draft-ietf-keyprov-dskpp-00.txt   draft-ietf-keyprov-dskpp-01.txt 
KEYPROV Working Group A. Doherty KEYPROV Working Group A. Doherty
Internet-Draft RSA, The Security Division of EMC Internet-Draft RSA, The Security Division of EMC
Intended status: Standards Track M. Pei Intended status: Standards Track M. Pei
Expires: January 27, 2008 VeriSign, Inc. Expires: May 1, 2008 Verisign, Inc.
M. Nystroem
RSA, The Security Division of EMC
S. Machani S. Machani
Diversinet Corp. Diversinet Corp.
July 26, 2007 M. Nystrom
RSA, The Security Division of EMC
October 29, 2007
Dynamic Symmetric Key Provisioning Protocol (DSKPP) Dynamic Symmetric Key Provisioning Protocol (DSKPP)
draft-ietf-keyprov-dskpp-00.txt draft-ietf-keyprov-dskpp-01.txt
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Copyright Notice Copyright Notice
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2007).
Abstract Abstract
DSKPP is a client-server protocol for initialization (and DSKPP is a client-server protocol for initialization (and
configuration) of symmetric keys to locally and remotely accessible configuration) of symmetric keys to locally and remotely accessible
cryptographic modules. The protocol can be run with or without cryptographic modules. The protocol can be run with or without
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liaison requests. It is intended, therefore, that this document or a liaison requests. It is intended, therefore, that this document or a
successor version thereto will become the basis for subsequent successor version thereto will become the basis for subsequent
progression of a symmetric key provisioning protocol specification on progression of a symmetric key provisioning protocol specification on
the standards track. the standards track.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 7
1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2. Background . . . . . . . . . . . . . . . . . . . . . . . 7 1.2. Background . . . . . . . . . . . . . . . . . . . . . . . 7
2. Notation and Terminology . . . . . . . . . . . . . . . . . . 8 2. Requirements Notation and Terminology . . . . . . . . . . . . 8
3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1. A cryptographic module obtains a symmetric key . . . . . 9 3.1. Single Key Request . . . . . . . . . . . . . . . . . . . 11
3.2. A cryptographic module acquires multiple symmetric 3.2. Multiple Key Requests . . . . . . . . . . . . . . . . . . 11
keys of different types . . . . . . . . . . . . . . . . . 9 3.3. Session Time-Out Policy . . . . . . . . . . . . . . . . . 11
3.3. A provisioning server imposes a validity period policy 3.4. Outsourced Provisioning . . . . . . . . . . . . . . . . . 12
for provisioning sessions . . . . . . . . . . . . . . . . 10 3.5. Key Renewal . . . . . . . . . . . . . . . . . . . . . . . 12
3.4. A symmetric key issuer uses a third party provisioning 3.6. Pre-Loaded Key Replacement . . . . . . . . . . . . . . . 12
service provider . . . . . . . . . . . . . . . . . . . . 10 3.7. Pre-Shared Transport Key . . . . . . . . . . . . . . . . 12
3.5. A cryptographic module renews its symmetric key with 3.8. SMS-Based Key Transport . . . . . . . . . . . . . . . . . 13
the same key ID . . . . . . . . . . . . . . . . . . . . . 10 3.9. Non-Protected Transport Layer . . . . . . . . . . . . . . 13
3.6. An administrator initiates a symmetric key replacement 3.10. Non-Authenticated Transport Layer . . . . . . . . . . . . 13
before it can be used . . . . . . . . . . . . . . . . . . 10 4. DSKPP Overview . . . . . . . . . . . . . . . . . . . . . . . 13
3.7. A cryptographic module hosted by a smart card uses a 4.1. Entities . . . . . . . . . . . . . . . . . . . . . . . . 13
pre-shared transport key to communicate with the 4.2. Overview of Protocol Usage . . . . . . . . . . . . . . . 15
provisioning server . . . . . . . . . . . . . . . . . . . 11 4.3. Four-Pass Protocol Usage . . . . . . . . . . . . . . . . 18
3.8. A cryptographic module hosted by a mobile device 4.3.1. Message Flow . . . . . . . . . . . . . . . . . . . . 19
downloads a symmetric key through SMS . . . . . . . . . . 11 4.3.2. Generation of Symmetric Keys for Cryptographic
3.9. A cryptographic module acquires a symmetric key over a Modules . . . . . . . . . . . . . . . . . . . . . . . 20
transport protocol that does not ensure data 4.3.3. Client Authentication . . . . . . . . . . . . . . . . 23
confidentiality . . . . . . . . . . . . . . . . . . . . . 12 4.3.4. Key Confirmation . . . . . . . . . . . . . . . . . . 23
3.10. A cryptographic module acquires a symmetric key over a 4.3.5. Server Authentication . . . . . . . . . . . . . . . . 23
transport protocol that does not provide authentication . 12 4.4. Two-Pass Protocol Usage . . . . . . . . . . . . . . . . . 24
4. DSKPP . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4.4.1. Message Flow . . . . . . . . . . . . . . . . . . . . 26
4.1. Entities . . . . . . . . . . . . . . . . . . . . . . . . 12 4.4.2. Key Confirmation . . . . . . . . . . . . . . . . . . 27
4.2. Principles of Operation . . . . . . . . . . . . . . . . . 14 4.4.3. Server Authentication . . . . . . . . . . . . . . . . 27
4.2.1. Four-pass DSKPP . . . . . . . . . . . . . . . . . . . 15 4.5. One-Pass Protocol Usage . . . . . . . . . . . . . . . . . 28
4.2.2. Two-pass DSKPP . . . . . . . . . . . . . . . . . . . 19 4.5.1. Message Flow . . . . . . . . . . . . . . . . . . . . 29
4.2.3. One-pass DSKPP . . . . . . . . . . . . . . . . . . . 21 4.5.2. Key Confirmation . . . . . . . . . . . . . . . . . . 30
4.3. Authentication . . . . . . . . . . . . . . . . . . . . . 22 4.5.3. Server Authentication . . . . . . . . . . . . . . . . 30
4.3.1. Client Authentication (Applicable to Four- and 5. Methods Common to More Than One Protocol Variant . . . . . . 31
Two-Pass DSKPP) . . . . . . . . . . . . . . . . . . . 22 5.1. The DSKPP One-Way Pseudorandom Function, DSKPP-PRF . . . 31
4.3.2. Server Authentication . . . . . . . . . . . . . . . . 25 5.1.1. Introduction . . . . . . . . . . . . . . . . . . . . 31
4.4. Symmetric Key Container Format . . . . . . . . . . . . . 25 5.1.2. Declaration . . . . . . . . . . . . . . . . . . . . . 32
4.5. The DSKPP One-Way Pseudorandom Function, DSKPP-PRF . . . 25 5.2. Encryption of Pseudorandom Nonces Sent from the DSKPP
4.5.1. Introduction . . . . . . . . . . . . . . . . . . . . 25 Client (Applicable to Four-Pass and Two-Pass DSKPP) . . . 32
4.5.2. Declaration . . . . . . . . . . . . . . . . . . . . . 26 5.3. Client Authentication Mechanisms (Applicable to Four-
4.6. Generation of Symmetric Keys for Cryptographic Modules . 26 and Two-Pass DSKPP) . . . . . . . . . . . . . . . . . . . 32
4.7. Encryption of Pseudorandom Nonces Sent from the DSKPP 5.3.1. Device Certificate . . . . . . . . . . . . . . . . . 33
Client . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.3.2. Device Identifier . . . . . . . . . . . . . . . . . . 33
4.8. MAC calculations . . . . . . . . . . . . . . . . . . . . 27 5.3.3. Authentication Code . . . . . . . . . . . . . . . . . 33
4.8.1. Four-pass DSKPP . . . . . . . . . . . . . . . . . . . 27 5.4. Client Authentication Examples . . . . . . . . . . . . . 36
4.8.2. Two-pass DSKPP . . . . . . . . . . . . . . . . . . . 28 5.4.1. Example Using a MAC from an Authentication Code . . . 36
4.8.3. One-pass DSKPP . . . . . . . . . . . . . . . . . . . 29 5.4.2. Example Using a Device Certificate . . . . . . . . . 36
4.9. DSKPP Schema Basics . . . . . . . . . . . . . . . . . . . 30 6. Four-Pass Protocol . . . . . . . . . . . . . . . . . . . . . 36
4.9.1. The AbstractRequestType Type . . . . . . . . . . . . 31 6.1. XML Basics . . . . . . . . . . . . . . . . . . . . . . . 36
4.9.2. The AbstractResponseType Type . . . . . . . . . . . . 31 6.2. Round-Trip #1: <KeyProvClientHello> and
4.9.3. The VersionType Type . . . . . . . . . . . . . . . . 32 <KeyProvServerHello> . . . . . . . . . . . . . . . . . . 37
4.9.4. The IdentifierType Type . . . . . . . . . . . . . . . 32 6.2.1. Examples . . . . . . . . . . . . . . . . . . . . . . 37
4.9.5. The StatusCode Type . . . . . . . . . . . . . . . . . 32 6.2.2. Components of the <KeyProvClientHello> Request . . . 41
4.9.6. The DeviceIdentifierDataType Type . . . . . . . . . . 34 6.2.3. Components of the <KeyProvServerHello> Response . . . 45
4.9.7. The TokenPlatformInfoType and PlatformType Types . . 35 6.3. Round-Trip #2: <KeyProvClientNonce> and
4.9.8. The NonceType Type . . . . . . . . . . . . . . . . . 35 <KeyProvServerFinished> . . . . . . . . . . . . . . . . . 46
4.9.9. The AlgorithmsType Type . . . . . . . . . . . . . . . 36 6.3.1. Examples . . . . . . . . . . . . . . . . . . . . . . 46
4.9.10. The ProtocolVariantsType and the 6.3.2. Components of a <KeyProvClientNonce> Request . . . . 47
TwoPassSupportType Types . . . . . . . . . . . . . . 36 6.3.3. Components of a <KeyProvServerFinished> Response . . 48
4.9.11. The KeyContainersFormatTypeType . . . . . . . . . . . 37 6.4. DSKPP Server Results: The StatusCode Type . . . . . . . 49
4.9.12. The AuthenticationDataType Type . . . . . . . . . . . 38 7. Two-Pass Protocol . . . . . . . . . . . . . . . . . . . . . . 50
4.9.13. The PayloadType Type . . . . . . . . . . . . . . . . 40 7.1. XML Basics . . . . . . . . . . . . . . . . . . . . . . . 50
4.9.14. The MacType Type . . . . . . . . . . . . . . . . . . 40 7.2. Round-Trip #1: <KeyProvClientHello> and
4.9.15. The KeyContainerType Type . . . . . . . . . . . . . . 40 <KeyProvServerFinished> . . . . . . . . . . . . . . . . . 51
4.9.16. The ExtensionsType and the AbstractExtensionType 7.2.1. Examples . . . . . . . . . . . . . . . . . . . . . . 51
Types . . . . . . . . . . . . . . . . . . . . . . . . 41 7.2.2. Components of the <KeyProvClientHello> Request . . . 59
4.10. DSKPP Messages . . . . . . . . . . . . . . . . . . . . . 41 7.2.3. Components of a <KeyProvServerFinished> Response . . 60
4.10.1. Introduction . . . . . . . . . . . . . . . . . . . . 41 7.3. DSKPP Server Results: The StatusCode Type . . . . . . . 62
4.10.2. DSKPP Initialization (OPTIONAL) . . . . . . . . . . . 41 8. One-Pass Protocol . . . . . . . . . . . . . . . . . . . . . . 63
4.10.3. The DSKPP Client's Initial PDU (2- and 4-Pass) . . . 43 8.1. XML Basics . . . . . . . . . . . . . . . . . . . . . . . 63
4.10.4. The DSKPP Server's Initial PDU (4-Pass Only) . . . . 46 8.2. Server to Client Only: <KeyProvServerFinished> . . . . . 64
4.10.5. The DSKPP Client's Second PDU (4-Pass Only) . . . . . 47 8.2.1. Example . . . . . . . . . . . . . . . . . . . . . . . 64
4.10.6. The DSKPP Server's Final PDU (1-, 2-, and 4-Pass) . . 48 8.2.2. Components of a <KeyProvServerFinished> Response . . 65
4.11. Protocol Extensions . . . . . . . . . . . . . . . . . . . 50 9. Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.11.1. The ClientInfoType Type . . . . . . . . . . . . . . . 50 9.1. XML Basics . . . . . . . . . . . . . . . . . . . . . . . 66
4.11.2. The ServerInfoType Type . . . . . . . . . . . . . . . 50 9.2. Example . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.11.3. The KeyInitializationDataType Type . . . . . . . . . 51 9.3. Components of the <KeyProvTrigger> Message . . . . . . . 67
5. Protocol Bindings . . . . . . . . . . . . . . . . . . . . . . 52 10. Extensibility . . . . . . . . . . . . . . . . . . . . . . . . 68
5.1. General Requirements . . . . . . . . . . . . . . . . . . 52 10.1. The ClientInfoType Type . . . . . . . . . . . . . . . . . 68
5.2. HTTP/1.1 Binding for DSKPP . . . . . . . . . . . . . . . 52 10.2. The ServerInfoType Type . . . . . . . . . . . . . . . . . 68
5.2.1. Introduction . . . . . . . . . . . . . . . . . . . . 52 10.3. The KeyInitializationDataType Type . . . . . . . . . . . 68
5.2.2. Identification of DSKPP Messages . . . . . . . . . . 53 11. Key Initialization Profiles of Two- and One-Pass DSKPP . . . 69
5.2.3. HTTP Headers . . . . . . . . . . . . . . . . . . . . 53 11.1. Introduction . . . . . . . . . . . . . . . . . . . . . . 69
5.2.4. HTTP Operations . . . . . . . . . . . . . . . . . . . 53 11.2. Key Transport Profile . . . . . . . . . . . . . . . . . . 69
5.2.5. HTTP Status Codes . . . . . . . . . . . . . . . . . . 53 11.2.1. Introduction . . . . . . . . . . . . . . . . . . . . 69
5.2.6. HTTP Authentication . . . . . . . . . . . . . . . . . 54 11.2.2. Identification . . . . . . . . . . . . . . . . . . . 69
5.2.7. Initialization of DSKPP . . . . . . . . . . . . . . . 54 11.2.3. Payloads . . . . . . . . . . . . . . . . . . . . . . 69
5.2.8. Example Messages . . . . . . . . . . . . . . . . . . 54 11.3. Key Wrap Profile . . . . . . . . . . . . . . . . . . . . 70
6. DSKPP Schema . . . . . . . . . . . . . . . . . . . . . . . . 55 11.3.1. Introduction . . . . . . . . . . . . . . . . . . . . 70
7. Security Considerations . . . . . . . . . . . . . . . . . . . 63 11.3.2. Identification . . . . . . . . . . . . . . . . . . . 71
7.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 63 11.3.3. Payloads . . . . . . . . . . . . . . . . . . . . . . 71
7.2. Active Attacks . . . . . . . . . . . . . . . . . . . . . 63 11.4. Passphrase-Based Key Wrap Profile . . . . . . . . . . . . 72
7.2.1. Introduction . . . . . . . . . . . . . . . . . . . . 63 11.4.1. Introduction . . . . . . . . . . . . . . . . . . . . 72
7.2.2. Message Modifications . . . . . . . . . . . . . . . . 64 11.4.2. Identification . . . . . . . . . . . . . . . . . . . 72
7.2.3. Message Deletion . . . . . . . . . . . . . . . . . . 65 11.4.3. Payloads . . . . . . . . . . . . . . . . . . . . . . 72
7.2.4. Message Insertion . . . . . . . . . . . . . . . . . . 65 12. Protocol Bindings . . . . . . . . . . . . . . . . . . . . . . 73
7.2.5. Message Replay . . . . . . . . . . . . . . . . . . . 66 12.1. General Requirements . . . . . . . . . . . . . . . . . . 74
7.2.6. Message Reordering . . . . . . . . . . . . . . . . . 66 12.2. HTTP/1.1 Binding for DSKPP . . . . . . . . . . . . . . . 74
7.2.7. Man-in-the-Middle . . . . . . . . . . . . . . . . . . 66 12.2.1. Introduction . . . . . . . . . . . . . . . . . . . . 74
7.3. Passive Attacks . . . . . . . . . . . . . . . . . . . . . 66 12.2.2. Identification of DSKPP Messages . . . . . . . . . . 74
7.4. Cryptographic Attacks . . . . . . . . . . . . . . . . . . 67 12.2.3. HTTP Headers . . . . . . . . . . . . . . . . . . . . 74
7.5. Attacks on the Interaction between DSKPP and User 12.2.4. HTTP Operations . . . . . . . . . . . . . . . . . . . 74
Authentication . . . . . . . . . . . . . . . . . . . . . 67 12.2.5. HTTP Status Codes . . . . . . . . . . . . . . . . . . 75
7.6. Additional Considerations Specific to 2- and 1-pass 12.2.6. HTTP Authentication . . . . . . . . . . . . . . . . . 75
DSKPP . . . . . . . . . . . . . . . . . . . . . . . . . . 68 12.2.7. Initialization of DSKPP . . . . . . . . . . . . . . . 75
7.6.1. Client Contributions to K_TOKEN Entropy . . . . . . . 68 12.2.8. Example Messages . . . . . . . . . . . . . . . . . . 75
7.6.2. Key Confirmation . . . . . . . . . . . . . . . . . . 68 13. DSKPP Schema . . . . . . . . . . . . . . . . . . . . . . . . 76
7.6.3. Server Authentication . . . . . . . . . . . . . . . . 68 14. Security Considerations . . . . . . . . . . . . . . . . . . . 85
7.6.4. Client Authentication . . . . . . . . . . . . . . . . 68 14.1. General . . . . . . . . . . . . . . . . . . . . . . . . . 85
7.6.5. Key Protection in the Passphrase Profile . . . . . . 69 14.2. Active Attacks . . . . . . . . . . . . . . . . . . . . . 85
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 70 14.2.1. Introduction . . . . . . . . . . . . . . . . . . . . 85
9. Intellectual Property Considerations . . . . . . . . . . . . 70 14.2.2. Message Modifications . . . . . . . . . . . . . . . . 85
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 70 14.2.3. Message Deletion . . . . . . . . . . . . . . . . . . 87
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 70 14.2.4. Message Insertion . . . . . . . . . . . . . . . . . . 87
11.1. Normative references . . . . . . . . . . . . . . . . . . 70 14.2.5. Message Replay . . . . . . . . . . . . . . . . . . . 87
11.2. Informative references . . . . . . . . . . . . . . . . . 71 14.2.6. Message Reordering . . . . . . . . . . . . . . . . . 88
Appendix A. Key Initialization Profiles of DSKPP . . . . . . . . 72 14.2.7. Man-in-the-Middle . . . . . . . . . . . . . . . . . . 88
A.1. Introduction . . . . . . . . . . . . . . . . . . . . . . 73 14.3. Passive Attacks . . . . . . . . . . . . . . . . . . . . . 88
A.2. Key Transport Profile . . . . . . . . . . . . . . . . . . 73 14.4. Cryptographic Attacks . . . . . . . . . . . . . . . . . . 88
A.2.1. Introduction . . . . . . . . . . . . . . . . . . . . 73 14.5. Attacks on the Interaction between DSKPP and User
A.2.2. Identification . . . . . . . . . . . . . . . . . . . 73 Authentication . . . . . . . . . . . . . . . . . . . . . 89
A.2.3. Payloads . . . . . . . . . . . . . . . . . . . . . . 73 14.6. Additional Considerations Specific to 2- and 1-pass
A.3. Key wrap profile . . . . . . . . . . . . . . . . . . . . 74 DSKPP . . . . . . . . . . . . . . . . . . . . . . . . . . 89
A.3.1. Introduction . . . . . . . . . . . . . . . . . . . . 74 14.6.1. Client Contributions to K_TOKEN Entropy . . . . . . . 89
A.3.2. Identification . . . . . . . . . . . . . . . . . . . 74 14.6.2. Key Confirmation . . . . . . . . . . . . . . . . . . 90
A.3.3. Payloads . . . . . . . . . . . . . . . . . . . . . . 74 14.6.3. Server Authentication . . . . . . . . . . . . . . . . 90
A.4. Passphrase-based key wrap profile . . . . . . . . . . . . 76 14.6.4. Client Authentication . . . . . . . . . . . . . . . . 90
A.4.1. Introduction . . . . . . . . . . . . . . . . . . . . 76 14.6.5. Key Protection in the Passphrase Profile . . . . . . 91
A.4.2. Identification . . . . . . . . . . . . . . . . . . . 76 15. Internationalization Considerations . . . . . . . . . . . . . 91
A.4.3. Payloads . . . . . . . . . . . . . . . . . . . . . . 76 16. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 92
Appendix B. Example Messages . . . . . . . . . . . . . . . . . . 77 17. Intellectual Property Considerations . . . . . . . . . . . . 92
B.1. Example Messages in a Four-pass Exchange . . . . . . . . 77 18. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 92
B.1.1. Example of a DSKPP Initialization (Trigger) Message . 78 19. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 92
B.1.2. Example of a <ClientHello> Message . . . . . . . . . 79 20. References . . . . . . . . . . . . . . . . . . . . . . . . . 93
B.1.3. Example of a <ServerHello> Message . . . . . . . . . 80 20.1. Normative references . . . . . . . . . . . . . . . . . . 93
B.1.4. Example of a <ClientNonce> Message . . . . . . . . . 80 20.2. Informative references . . . . . . . . . . . . . . . . . 94
B.1.5. Example of a <ServerFinished> Message . . . . . . . . 80 Appendix A. Integration with PKCS #11 . . . . . . . . . . . . . 95
B.2. Example Messages in a Two- or One-pass Exchange . . . . . 81 A.1. The 4-pass Variant . . . . . . . . . . . . . . . . . . . 96
B.2.1. Example of a <ClientHello> Message Indicating A.2. The 2-pass Variant . . . . . . . . . . . . . . . . . . . 96
Support for Two-pass DSKPP . . . . . . . . . . . . . 81 A.3. The 1-pass Variant . . . . . . . . . . . . . . . . . . . 98
B.2.2. Example of a <ServerFinished> Message Using the Appendix B. Example of DSKPP-PRF Realizations . . . . . . . . . 100
Key Transport Profile . . . . . . . . . . . . . . . . 83 B.1. Introduction . . . . . . . . . . . . . . . . . . . . . . 101
B.2.3. Example of a <ServerFinished> Message Using the B.2. DSKPP-PRF-AES . . . . . . . . . . . . . . . . . . . . . . 101
Key Wrap Profile . . . . . . . . . . . . . . . . . . 85 B.2.1. Identification . . . . . . . . . . . . . . . . . . . 101
B.2.4. Example of a <ServerFinished> Message using the B.2.2. Definition . . . . . . . . . . . . . . . . . . . . . 101
Passphrase-based Key Wrap Profile . . . . . . . . . . 86 B.2.3. Example . . . . . . . . . . . . . . . . . . . . . . . 102
Appendix C. Requirements . . . . . . . . . . . . . . . . . . . . 88 B.3. DSKPP-PRF-SHA256 . . . . . . . . . . . . . . . . . . . . 102
Appendix D. Integration with PKCS #11 . . . . . . . . . . . . . 90 B.3.1. Identification . . . . . . . . . . . . . . . . . . . 102
D.1. The 4-pass Variant . . . . . . . . . . . . . . . . . . . 91 B.3.2. Definition . . . . . . . . . . . . . . . . . . . . . 103
D.2. The 2-pass Variant . . . . . . . . . . . . . . . . . . . 91 B.3.3. Example . . . . . . . . . . . . . . . . . . . . . . . 104
D.3. The 1-pass Variant . . . . . . . . . . . . . . . . . . . 93 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 104
Appendix E. Example of DSKPP-PRF Realizations . . . . . . . . . 95 Intellectual Property and Copyright Statements . . . . . . . . . 106
E.1. Introduction . . . . . . . . . . . . . . . . . . . . . . 96
E.2. DSKPP-PRF-AES . . . . . . . . . . . . . . . . . . . . . . 96
E.2.1. Identification . . . . . . . . . . . . . . . . . . . 96
E.2.2. Definition . . . . . . . . . . . . . . . . . . . . . 96
E.2.3. Example . . . . . . . . . . . . . . . . . . . . . . . 97
E.3. DSKPP-PRF-SHA256 . . . . . . . . . . . . . . . . . . . . 97
E.3.1. Identification . . . . . . . . . . . . . . . . . . . 97
E.3.2. Definition . . . . . . . . . . . . . . . . . . . . . 98
E.3.3. Example . . . . . . . . . . . . . . . . . . . . . . . 99
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 99
Intellectual Property and Copyright Statements . . . . . . . . . 100
1. Introduction 1. Introduction
1.1. Scope 1.1. Scope
This document describes a client-server protocol for initialization This document describes a client-server protocol for initialization
(and configuration) of symmetric keys to locally and remotely (and configuration) of symmetric keys to locally and remotely
accessible cryptographic modules. The protocol can be run with or accessible cryptographic modules. The protocol can be run with or
without private-key capabilities in the cryptographic modules, and without private-key capabilities in the cryptographic modules, and
with or without an established public-key infrastructure. The with or without an established public-key infrastructure. The
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to any other entities than the server and the cryptographic to any other entities than the server and the cryptographic
module itself. module itself.
o Provide a secure method of generating and transporting o Provide a secure method of generating and transporting
symmetric keys to a cryptographic module in environments where symmetric keys to a cryptographic module in environments where
near real-time communication is not possible. near real-time communication is not possible.
o Provide a secure method of transporting pre-generated (i.e., o Provide a secure method of transporting pre-generated (i.e.,
legacy) keys to a cryptographic module. legacy) keys to a cryptographic module.
o Provide a solution that is easy to administer and scales well. o Provide a solution that is easy to administer and scales well.
The mechanism is intended for general use within computer and The mechanism is intended for general use within computer and
communications systems employing symmetric cryptographic modules that communications systems employing symmetric key cryptographic modules
are locally (i.e., over-the-wire) or remotely (i.e., over-the-air) that are locally (i.e., over-the-wire) or remotely (i.e., over-the-
accessible. air) accessible.
1.2. Background 1.2. Background
A symmetric cryptographic module may be hosted by a hand-held A locally accessible symmetric key cryptographic module may be hosted
hardware device (e.g., a mobile phone), a hardware device connected by, for example, a hardware device connected to a personal computer
to a personal computer through an electronic interface, such as USB, through an electronic interface, such as USB, or a software
or a software application resident on a personal computer. The application resident on a personal computer. A remotely accessible
cryptographic module offers symmetric cryptographic functionality symmetric key cryptographic module may be hosted by, for example, any
that may be used to authenticate a user towards some service, perform device that can support over-the-air communication, such as a hand-
data encryption, etc. Increasingly, these modules enable their held hardware device (e.g., a mobile phone). The cryptographic
module itself offers symmetric key cryptographic functionality that
may be used to authenticate a user towards some service, perform data
encryption, etc. Increasingly, these modules enable their
programmatic initialization as well as programmatic retrieval of programmatic initialization as well as programmatic retrieval of
their output values. This document intends to meet the need for an their output values. This document intends to meet the need for an
open and inter-operable mechanism to programmatically initialize and open and inter-operable mechanism to programmatically initialize and
configure symmetric keys to locally and remotely accessible configure symmetric keys to locally and remotely accessible
cryptographic modules. cryptographic modules.
The target mechanism addressed herein is a symmetric key provisioning The target mechanism makes use of a symmetric key provisioning
server. In an ideal deployment scenario, near real-time server. In an ideal deployment scenario, near real-time
communication is possible between the provisioning server and the communication is possible between the provisioning server and the
cryptographic module. In such an environment, it is possible for the cryptographic module. In such an environment, it is possible for the
cryptographic module and provisioning server to mutually generate a cryptographic module and provisioning server to mutually generate a
symmetric key, and to ensure that keys are not transported between symmetric key, and to ensure that keys are not transported between
them. them.
There are, however, several deployment scenarios that make mutual key There are, however, several deployment scenarios that make mutual key
generation less suitable. Specifically, scenarios where near real- generation less suitable. Specifically, scenarios where near real-
time communication between the symmetric key provisioning server and time communication between the symmetric key provisioning server and
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describing three variations to DSKPP for the provisioning of describing three variations to DSKPP for the provisioning of
symmetric keys in two round trips or less. The four-pass (i.e., two symmetric keys in two round trips or less. The four-pass (i.e., two
round-trip) variant enables key generation in near real-time. With round-trip) variant enables key generation in near real-time. With
this variant, keys are mutually generated by the provisioning server this variant, keys are mutually generated by the provisioning server
and cryptographic module; provisioned keys are not transferred over- and cryptographic module; provisioned keys are not transferred over-
the-wire or over-the-air. In contrast, two- and one-pass variants the-wire or over-the-air. In contrast, two- and one-pass variants
enable secure and efficient download and installation of symmetric enable secure and efficient download and installation of symmetric
keys to a cryptographic module in environments where near real-time keys to a cryptographic module in environments where near real-time
communication is not possible. communication is not possible.
2. Notation and Terminology 2. Requirements Notation and Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
The following notations are used in this document: The following notations are used in this document:
|| String concatenation || String concatenation
[x] Optional element x [x] Optional element x
A ^ B Exclusive-OR operation on strings A and B (where A A ^ B Exclusive-OR operation on strings A and B (where A
and B are of equal length) and B are of equal length)
DSKPP client Manages communication between the symmetric ENC_X(Y) Encryption of message Y with symmetric key X, using a
defined block cipher
ENC_PX(Y) Encryption using message Y with a public key X
KDF_X(Y) Key derivation function that generates an arbitrary
number of octets of output using secret X and seed Y
DSKPP-PRF_X(Y,Z) Pseudo random function that generates a fixed
number Z of octets using secret X and seed Y (used in
DSKPP methods for MAC computations and key
derivation)
MAC_X(Y) Keyed message authentication code computed over Y
with symmetric key X
SIGN_x(Y) Function that provides authentication and integrity
protection of message content Y using private key x
B64(X) Base 64 encoding of string X
H(X) Hash function applied to X
Alg_List List of encryption and MAC algorithms supported by
the client
Alg_Sel Algorithms list selected by the server for the DSKPP
protocol run
DSKPP client Manages communication between the symmetric key
cryptographic module and the DSKPP server cryptographic module and the DSKPP server
DSKPP server The symmetric key provisioning server that DSKPP server The symmetric key provisioning server that
participates in the DSKPP protocol run participates in the DSKPP protocol run
Issuer The organization that issues or authorizes issuance
of the symmetric key to the end user of the symmetric
key cryptographic module (e.g., a bank who issues
one-time password authentication tokens to their
retail banking users)
ID_C Identifier for DSKPP client ID_C Identifier for DSKPP client
ID_S Identifier for DSKPP server ID_S Identifier for DSKPP server
AUTHCODE Client Authentication Code comprised of a string of
numeric characters known to the device and the server
and containing an identifier and a password (the
AUTHCODE may be used to derive the AUTHDATA during
the DSKPP protocol exchange)
AUTHDATA Client Authentication Data that may be derived from
the AUTHCODE or using the client private key,
k_CLIENT
K Key used to encrypt R_C (either K_SERVER or K_SHARED) K Key used to encrypt R_C (either K_SERVER or K_SHARED)
K_AUTH Secret key used for server authentication purposes in
4-pass DSKPP K_AUTHCODE Secret key that is derived from AUTHCODE and used for
client authentication purposes
k_CLIENT Private key of the DSKPP client
K_CLIENT Public key of the DSKPP client K_CLIENT Public key of the DSKPP client
K_DERIVED Secret key derived from a passphrase that is known to K_DERIVED Secret key derived from a passphrase that is known to
both the DSKPP client or user and the DSKPP server both the DSKPP client or user and the DSKPP server
K_MAC Secret key used for key confirmation and server K_MAC Secret key used for key confirmation and server
authentication purposes, and generated in DSKPP authentication purposes, and generated in DSKPP
K_MAC' A second secret key used for server authentication K_MAC' A second secret key used for server authentication
purposes in 2- and 1-pass DSKPP purposes in 2- and 1-pass DSKPP
K_SERVER Public key of the DSKPP server K_SERVER Public key of the DSKPP server
K_SHARED Secret key shared between the DSKPP client and the K_SHARED Secret key shared between the DSKPP client and the
DSKPP server DSKPP server
K_TOKEN Secret key used for cryptographic module K_TOKEN Secret key used for cryptographic module
computations, and generated in DSKPP computations, and generated in DSKPP
K_CONFDATA Key configuration data carried within the key
container
R Pseudorandom value chosen by the DSKPP client and R Pseudorandom value chosen by the DSKPP client and
used for MAC computations, which is mandatory for used for MAC computations, which is mandatory for
2-pass DSKPP and optional for 4-pass 2-pass DSKPP and optional for 4-pass
R_C Pseudorandom value chosen by the DSKPP client and R_C Pseudorandom value chosen by the DSKPP client and
used as input to the generation of K_TOKEN used as input to the generation of K_TOKEN
R_S Pseudorandom value chosen by the DSKPP server and R_S Pseudorandom value chosen by the DSKPP server and
used as input to the generation of K_TOKEN used as input to the generation of K_TOKEN
URL_S Server address as a URL
I Unsigned integer representing a counter value that is
monotonically increasing and guaranteed not to be
used again by the server towards the cryptographic
module
I' Similar to I except I' is always higher than I
The following typographical convention is used in the body of the The following typographical convention is used in the body of the
text: <XMLElement>. text: <XMLElement>.
3. Use Cases 3. Use Cases
This section describes typical use cases. This section describes typical use cases.
3.1. A cryptographic module obtains a symmetric key 3.1. Single Key Request
A cryptographic module hosted by a device, such as a mobile phone, A cryptographic module hosted by a device, such as a mobile phone,
makes a request for a symmetric key from a provisioning server. makes a request for a symmetric key from a provisioning server.
Depending upon how the system is deployed, the provisioning server Depending upon how the system is deployed, the provisioning server
may generate a new key on-the-fly or use a pre-generated key, e.g., may generate a new key on-the-fly or use a pre-generated key, e.g.,
one provided by a legacy back-end issuance server. The provisioning one provided by a legacy back-end issuance server. The provisioning
server assigns a unique key ID to the symmetric key and provisions it server assigns a unique key ID to the symmetric key and provisions it
to the cryptographic module. to the cryptographic module.
3.2. A cryptographic module acquires multiple symmetric keys of 3.2. Multiple Key Requests
different types
A cryptographic module makes multiple requests for symmetric keys A cryptographic module makes multiple requests for symmetric keys
from the same provisioning server. The symmetric keys may or may not from the same provisioning server. The symmetric keys may or may not
be of the same type, i.e., the keys may be used with different be of the same type, i.e., the keys may be used with different
symmetric cryptographic algorithms, including the HMAC-Based One-Time symmetric key cryptographic algorithms, including one-time password
Password (HOTP), RSA SecurID, challenge-response, etc. authentication algorithms, and AES encryption algorithm.
3.3. A provisioning server imposes a validity period policy for 3.3. Session Time-Out Policy
provisioning sessions
Once a cryptographic module initiates a symmetric key request, the Once a cryptographic module initiates a symmetric key request, the
provisioning server may require that any subsequent actions to provisioning server may require that any subsequent actions to
complete the provisioning cycle occur within a certain time window. complete the provisioning cycle occur within a certain time window.
For example, an issuer may provide a time-limited authentication code For example, an issuer may provide a time-limited authentication code
to a user during registration, which the user will input into the to a user during registration, which the user will input into the
cryptographic module to authenticate themselves with the provisioning cryptographic module to authenticate themselves with the provisioning
server. As long as the user inputs a valid authentication code server. If the user inputs a valid authentication code within the
within the fixed time period established by the issuer, the server fixed time period established by the issuer, the server will allow a
will provision a key to the cryptographic module hosted by the user's key to be provisioned to the cryptographic module hosted by the
device. user's device.
3.4. A symmetric key issuer uses a third party provisioning service 3.4. Outsourced Provisioning
provider
A symmetric key issuer outsources its key provisioning to a third A symmetric key issuer outsources its key provisioning to a third
party key provisioning server provider. The issuer is responsible party key provisioning server provider. The issuer is responsible
for authenticating and granting rights to users to acquire keys while for authenticating and granting rights to users to acquire keys while
acting as a proxy to the cryptographic module to acquire symmetric acting as a proxy to the cryptographic module to acquire symmetric
keys from the provisioning server; the cryptographic module keys from the provisioning server; the cryptographic module
communicates with the issuer proxy server, which forwards communicates with the issuer proxy server, which forwards
provisioning requests to the provisioning server. provisioning requests to the provisioning server.
3.5. A cryptographic module renews its symmetric key with the same key 3.5. Key Renewal
ID
A cryptographic module requests renewal of a symmetric key using the A cryptographic module requests renewal of a symmetric key using the
same key ID already associated with the key. Such a need may occur same key ID already associated with the key. Such a need may occur
in the case when a user wants to upgrade her device that houses the in the case when a user wants to upgrade her device that houses the
cryptographic module or when a key has expired. When a user uses the cryptographic module or when a key has expired. When a user uses the
same cryptographic module to, for example, perform strong same cryptographic module to, for example, perform strong
authentication at multiple Web login sites, keeping the same key ID authentication at multiple Web login sites, keeping the same key ID
removes the need for the user to register a new key ID at each site. removes the need for the user to register a new key ID at each site.
3.6. An administrator initiates a symmetric key replacement before it 3.6. Pre-Loaded Key Replacement
can be used
This use case represents a special case of symmetric key renewal in This use case represents a special case of symmetric key renewal in
which a local administrator can authenticate the user procedurally which a local administrator can authenticate the user procedurally
before initiating the provisioning process. It also allows for an before initiating the provisioning process. It also allows for an
issuer to pre-load a key onto a cryptographic module with a issuer to pre-load a key onto a cryptographic module with a
restriction that the key is replaced with a new key prior to use of restriction that the key is replaced with a new key prior to use of
the cryptographic module. the cryptographic module. Another variation of this use case is the
issuer who recycles devices. In this case, an issuer would provision
Bulk initialization under controlled conditions, e.g., during a new symmetric key to a cryptographic module hosted on a device that
manufacture, is likely to meet the security needs of most was previously owned by another user.
applications. However, reliance on a pre-disclosed secret is
unacceptable in some circumstances. One such circumstance is when
cryptographic modules are issued for classified government use or
high security applications. In such cases, the issuer requires the
ability to remove all secret information already installed on the
cryptographic module and replace it with symmetric keys established
under conditions controlled by the issuer.
Another variation of this use case is the issuer who recycles
devices. In this case, an issuer would provision a new symmetric key
to a cryptographic module hosted on a device that was previously
owned by another user.
Note that this use case is essentially the same as the last use case Note that this use case is essentially the same as the last use case
wherein the same key ID is used for renewal. wherein the same key ID is used for renewal.
3.7. A cryptographic module hosted by a smart card uses a pre-shared 3.7. Pre-Shared Transport Key
transport key to communicate with the provisioning server
A cryptographic module is loaded onto a smart card after the card is A cryptographic module is loaded onto a smart card after the card is
issued to a user. The symmetric key for the cryptographic module issued to a user. The symmetric key for the cryptographic module
will then be provisioned using a secure channel mechanism present in will then be provisioned using a secure channel mechanism present in
many smart card platforms. This allows a direct secure channel to be many smart card platforms. This allows a direct secure channel to be
established between the smart card chip and the provisioning server. established between the smart card chip and the provisioning server.
For example, the card commands (i.e., Application Protocol Data For example, the card commands (i.e., Application Protocol Data
Units, or APDUs) are encrypted with a pre-shared transport key and Units, or APDUs) are encrypted with a pre-shared transport key and
sent directly to the smart card chip, allowing secure post-issuance sent directly to the smart card chip, allowing secure post-issuance
in-the-field provisioning. This secure flow can pass Transport Layer in-the-field provisioning. This secure flow can pass Transport Layer
Security (TLS) and other transport security boundaries. Security (TLS) and other transport security boundaries.
Note that two pre-conditions for this use case are for the protocol Note that two pre-conditions for this use case are for the protocol
to be tunneled and the provisioning server to know the correct pre- to be tunneled and the provisioning server to know the correct pre-
established transport key. established transport key.
3.8. A cryptographic module hosted by a mobile device downloads a 3.8. SMS-Based Key Transport
symmetric key through SMS
A mobile device supports Short Message Service (SMS) but is not able A mobile device supports Short Message Service (SMS) but is not able
to support a data service allowing for HTTP or HTTPS transports. In to support a data service allowing for HTTP or HTTPS transports. In
addition, the cryptographic module can ensure that SMS will provide addition, an application may use a cryptographic module to enforce an
an acceptable level of protection for download of the symmetric key. acceptable level of protection for download of the symmetric key via
In such a case, the cryptographic module hosted by the mobile device SMS. In such a case, the cryptographic module hosted by the mobile
may initiate a symmetric key request from a desktop computer and ask device may initiate a symmetric key request from a desktop computer
the server to send the key to the mobile device through SMS. User and ask the server to send the key to the mobile device through SMS.
authentication is carried out via the online communication User authentication is carried out via the online communication
established between the desktop computer and the provisioning server. established between the desktop computer and the provisioning server.
3.9. A cryptographic module acquires a symmetric key over a transport 3.9. Non-Protected Transport Layer
protocol that does not ensure data confidentiality
Some devices are not able to support a secure transport channel such Some devices are not able to support a secure transport channel such
as SSL or TLS to provide data confidentiality. A cryptographic as SSL or TLS to provide data confidentiality. A cryptographic
module hosted by such a device requests a symmetric key from the module hosted by such a device requests a symmetric key from the
provisioning server. It is up to DSKPP to ensure data provisioning server. It is up to DSKPP to ensure data
confidentiality over non-secure networks. confidentiality over non-secure networks.
3.10. A cryptographic module acquires a symmetric key over a transport 3.10. Non-Authenticated Transport Layer
protocol that does not provide authentication
Some devices are not able to use a transport protocol that provides Some devices are not able to use a transport protocol that provides
server authentication such as SSL or TLS. A cryptographic module server authentication such as SSL or TLS. A cryptographic module
hosted by such a device wants to be sure that it sends a request for hosted by such a device wants to be sure that it sends a request for
a symmetric key to a legitimate provisioning server. It is up to a symmetric key to a legitimate provisioning server. It is up to
DSKPP to provide proper client and server authentication. DSKPP to provide proper client and server authentication.
4. DSKPP 4. DSKPP Overview
4.1. Entities 4.1. Entities
In principle, the protocol involves a DSKPP client and a DSKPP In principle, the protocol involves a DSKPP client and a DSKPP
server. The DSKPP client manages communication between the server. The DSKPP client manages communication between the
cryptographic module and the provisioning server. The DSKPP server cryptographic module and the provisioning server. The DSKPP server
herein represents the provisioning server. herein represents the provisioning server.
A high-level object model that describes the client-side entities and A high-level object model that describes the client-side entities and
how they relate to each other is shown in Figure 1. Conceptually, how they relate to each other is shown in Figure 1.
each entity represents the following:
User The person or client to whom devices are
issued
UserID A unique identifier for the user or client
Device A physical piece of hardware that hosts
symmetric cryptographic modules
DeviceID A unique identifier for the device
Cryptographic Module A low-level component of an application,
which enables symmetric cryptographic
functionality
CryptoModuleID A unique identifier for an instance of the
cryptographic module
Encryption Algorithms Encryption algorithms supported by the
cryptographic module
MAC Algorithms MAC algorithms supported by the cryptographic
module
Key Container An object that encapsulates a symmetric key
and its configuration data
KeyID A unique identifier for the symmetric key
Key Type The type of symmetric cryptographic methods
for which the key will be used (e.g., OATH
HOTP or RSA SecurID authentication, AES
encryption, etc.)
----------- ------------- ----------- -------------
| User | | Device | | User | | Device |
|---------|* owns *|-----------| |---------|* owns *|-----------|
| UserID |--------->| DeviceID | | UserID |--------->| DeviceID |
| ... | | ... | | ... | | ... |
----------- ------------- ----------- -------------
| 1 | 1
| |
| contains | contains
skipping to change at page 13, line 50 skipping to change at page 14, line 41
----------------------- -----------------------
|Key Container | |Key Container |
|---------------------| |---------------------|
|KeyID | |KeyID |
|Key Type | |Key Type |
|... | |... |
----------------------- -----------------------
Figure 1: Object Model Figure 1: Object Model
Conceptually, each entity represents the following:
User: The person or client to whom devices are
issued
UserID: A unique identifier for the user or client
Device: A physical piece of hardware or software
framework that hosts symmetric key
cryptographic modules
DeviceID: A unique identifier for the device
Cryptographic Module: A component of an application, which enables
symmetric key cryptographic functionality
CryptoModuleID: A unique identifier for an instance of the
cryptographic module
Encryption Algorithms: Encryption algorithms supported by the
cryptographic module
MAC Algorithms: MAC algorithms supported by the cryptographic
module
Key Container: An object that encapsulates a symmetric key
and its configuration data
KeyID: A unique identifier for the symmetric key
Key Type: The type of symmetric key cryptographic
methods for which the key will be used (e.g.,
OATH HOTP or RSA SecurID authentication, AES
encryption, etc.)
It is assumed that a device will host an application layered above It is assumed that a device will host an application layered above
the cryptographic module, and this application will manage the cryptographic module, and this application will manage
communication between the DSKPP client and cryptographic module. The communication between the DSKPP client and cryptographic module. The
manner in which the communicating application will transfer DSKPP manner in which the communicating application will transfer DSKPP
protocol elements to and from the cryptographic module is transparent protocol elements to and from the cryptographic module is transparent
to the DSKPP server. One method for this transfer is described in to the DSKPP server. One method for this transfer is described in
[CT-KIP-P11]. [CT-KIP-P11].
4.2. Principles of Operation 4.2. Overview of Protocol Usage
To initiate a DSKPP session, a user may use a browser to connect to a DSKPP enables symmetric key provisioning between a DSKPP server and
web server. The user may then identify and optionally authenticate DSKPP client. The DSKPP protocol supports the following types of
herself and possibly indicate how the DSKPP client has to contact the requests and responses:
DSKPP server. There are also other alternatives for DSKPP session
initiation, such as the DSKPP client being pre-configured to contact <KeyProvClientHello>
a certain DSKPP server, or the user being informed out-of-band about
the address of the DSKPP server. With this request, a DSKPP client initiates contact with the
DSKPP server, indicating what protocol versions and variants,
key types, encryption and MAC algorithms that it supports. In
addition, the request may include client authentication data
that the DSKPP server uses to verify proof-of-possession of
the device.
<KeyProvServerHello>
Upon reception of a <KeyProvClientHello> request, the DSKPP
server uses the <KeyProvServerHello> response to specify which
protocol version and variant, key type, encryption algorithm,
and MAC algorithm that will be used by the DSKPP server and
DSKPP client during the protocol run. The decision of which
variant, key type, and cryptographic algorithms to pick is
policy- and implementation-dependent and therefore outside the
scope of this document.
The <KeyProvServerHello> response includes the DSKPP server's
random nonce, R_S. The response also consists of information
about either a shared secret key, or its own public key, that
the DSKPP client uses when sending its protected random nonce,
R_C, in the <KeyProvClientNonce> request (see below).
Optionally, the DSKPP server may provide a MAC that the DSKPP
client may use for server authentication.
<KeyProvClientNonce>
With this request, a DSKPP client and DSKPP server securely
exchange protected data, e.g., the protected random nonce R_C.
In addition, the request may include client authentication
data that the DSKPP server uses to verify proof-of-possession
of the device.
<KeyProvServerFinished>
The <KeyProvServerFinished> response is a confirmation message
that includes a key container that holds configuration data,
and may also contain protected key material (this depends on
the protocol variant, as discussed below).
Optionally, the DSKPP server may provide a MAC that the DSKPP
client may use for server authentication.
To initiate a DSKPP session:
1. A user may use a browser to connect to a web server that is
running on some host. The user may then identify (and optionally
authenticate) herself (through some means that essentially are
out of scope for this document) and request a symmetric key.
2. A client application may request a symmetric key by invoking the
DSKPP client.
3. A DSKPP server may send a trigger message to a client
application, which would then invoke the DSKPP client.
To contact the DSKPP server:
1. A user may indicate how the DSKPP client is to contact a certain
DSKPP server during a browsing session.
2. A DSKPP client may be pre-configured to contact a certain DSKPP
server.
3. A user may be informed out-of-band about the location of the
DSKPP server.
Once the location of the DSKPP server is known, the DSKPP client and Once the location of the DSKPP server is known, the DSKPP client and
the DSKPP server engage in a 4-pass, 2-pass, or 1-pass protocol. the DSKPP server engage in a 4-pass, 2-pass, or 1-pass protocol.
With the four-pass variant, keys are mutually generated by the Depending upon the policy and implementation, a DSKPP server selects
provisioning server and cryptographic module; provisioned keys are which variant of the protocol to use: 4-pass, 2-pass, or 1-pass.
not transferred over-the-wire or over-the-air. Two- and one-pass With the four-pass variant, keys are mutually generated by the DSKPP
variants enable secure and efficient download and installation of server and DSKPP client; provisioned keys are not transferred over-
symmetric keys to a cryptographic module in environments where near the-wire or over-the-air. Two- and one-pass variants enable secure
real-time communication may not be possible. and efficient download and installation of symmetric keys to a DSKPP
client in environments where near real-time communication may not be
possible.Figure 2 shows which messages get exchanged during each type
of protocol run (4-pass, 2-pass, or 1-pass).
+---------------+ +---------------+
| | | |
| DSKPP client | | DSKPP server |
| | | |
+---------------+ +---------------+
| |
| [ <---- DSKPP trigger ----- ] |
| |
| ------- Client Hello -------> |
| (Applicable to 4- and 2-pass) |
| |
| <------ Server Hello -------- |
| (Applicable to 4-pass only) |
| |
| ------- Client Nonce -------> |
| (Applicable to 4-pass only) |
| |
| <----- Server Finished ------ |
| (Applicable to 4-, 2-, and 1-pass) |
| |
DSKPP protocol variants may be applied to the use cases described in Figure 2: The DSKPP protocol (with OPTIONAL preceding trigger)
Section 3, as shown below:
========================================================== The table below identifies which protocol variants may be applied to
the use cases from Section 3:
----------------------------------------------------------
Protocol Applicable Applicable Protocol Applicable Applicable
Variant Use Cases Deployment Scenarios Variant Use Cases Deployment Scenarios
========================================================== ----------------------------------------------------------
4-pass All but 3.6 and Near real-time 4-pass All but 3.6 and Near real-time
3.8 if mutual key communication is 3.8 if mutual key communication is
generation is desired; possible generation is desired; possible
none if transport of none if transport of
a pre-generated key a pre-generated key
is required
-----------------------------------------------------------
2-pass All Either near real-time 2-pass All Either near real-time
or non real-time or non real-time
communication may be communication may be
possible possible
-----------------------------------------------------------
1-pass All but 3.8 Either near real-time 1-pass All but 3.8 Either near real-time
or non real-time or non real-time
communication may be communication may be
possible possible
==========================================================
Figure 2: Mapping of use cases to protocol variants Figure 3: Mapping of protocol variants to use cases
4.2.1. Four-pass DSKPP 4.3. Four-Pass Protocol Usage
The 4-pass protocol flow is suitable for environments wherein there The 4-pass protocol flow is suitable for environments wherein there
is near real-time communication possible between the DSKPP client and is near real-time communication possible between the DSKPP client and
DSKPP server. It is not suitable for environments wherein DSKPP server. It is not suitable for environments wherein
administrative approval is a required step in the flow, nor for administrative approval is a required step in the flow, nor for
provisioning of pre-generated keys. The 4-pass protocol flow, shown provisioning of pre-generated keys.
in Figure 3 and expanded in Figure 4, consists of two round trips
between the DSKPP client and server.
+---------------+ +---------------+ The full four-pass protocol exchange is as follows:
| | | |
| DSKPP client | | DSKPP server |
| | | |
+---------------+ +---------------+
| |
| [ <---- DSKPP trigger ----- ] |
| |
| ------- Client Hello -------> |
| |
| <------ Server Hello -------- |
| |
| ------- Client Nonce -------> |
| |
| <----- Server Finished ------ |
| |
Figure 3: The 4-pass DSKPP protocol (with OPTIONAL preceeding [<Trigger>]:
trigger)
a. The DSKPP client sends a <ClientHello> message to the DSKPP [ID_Device], [ID_K], [URL_S], [R_S]
server. The message provides information to the DSKPP server
about the DSKPP versions, protocol variants, key types, <KeyProvClientHello>:
encryption and MAC algorithms supported by the cryptographic
module for the purposes of this protocol. The message may also [ID_Device], [ID_K], [R_S], Alg_List
include client authentication data, such as a certificate or
authentication code. <KeyProvServerHello>:
b. The DSKPP server responds to the DSKPP client with a
<ServerHello> message, whose content includes a random nonce, R_S, Alg_Sel, [K_SERVER], [DSKPP-PRF_K_MAC'("MAC 1 Computation" ||
R_S, along with information about the type of key to generate, [R] || R_S, len(R_S))
and the encryption algorithm chosen to protect sensitive data
sent in the protocol. The length of the nonce R_S may depend <KeyProvClientNonce>:
on the selected key type. The <ServerHello> message also
provides information about either a shared secret key to use AUTHDATA, ENC_PK_SERVER(R_C) OR AUTHDATA, ENC_K_SHARED(R_C)
for encrypting the cryptographic module's random nonce (see
description of <ClientNonce> below), or its own public key. <KeyProvServerFinished>:
Optionally, <ServerHello> may include a MAC that the DSKPP
client may use for server authentication. K_CONFDATA, DSKPP-PRF_K_MAC("MAC 2 Computation"||R_C, len(R_C))
c. Based on information contained in the <ServerHello> message,
the cryptographic module generates a random nonce, R_C. The The following subsections describe the exchange in more detail.
length of the nonce R_C may depend on the selected key type.
The cryptographic module encrypts R_C using the selected 4.3.1. Message Flow
encryption algorithm and with a key, K, that is either the
DSKPP server's public key, K_SERVER, or a shared secret key, The 4-pass protocol flow consists of two round trips between the
K_SHARED, as indicated by the DSKPP server. If K is equivalent DSKPP client and DSKPP server (see Figure 2), where each round-trip
to K_SERVER, then the cryptographic module SHOULD verify the involves two "passes", i.e., one request message and one response
server's certificate before using it to encrypt R_C. The DSKPP message:
client then sends the encrypted random nonce to the DSKPP
server in a <ClientNonce> message, and may include client Round-trip #1: Pass 1 = <KeyProvClientHello>, Pass 2 =
authentication data, such as a certificate or authentication <KeyProvServerHello>
code. Finally, the cryptographic module calculates a symmetric
key, K_TOKEN, of the selected type from the combination of the Round-trip #2: Pass 3 = <KeyProvClientNonce>, Pass 4 =
two random nonces R_S and R_C, the encryption key K, and <KeyProvServerFinished>
possibly some other data, using the DSKPP-PRF function defined
in Section 4.5. 4.3.1.1. Round-trip #1: <KeyProvClientHello> and <KeyProvServerHello>
d. The DSKPP server decrypts R_C, calculates K_TOKEN from the
combination of the two random nonces R_S and R_C, the The DSKPP client sends a <KeyProvClientHello> message to the DSKPP
encryption key K, and possibly some other data, using the server. The message provides information to the DSKPP server about
DSKPP-PRF function defined in Section 4.5. The server then the DSKPP versions, protocol variants, key types, encryption and MAC
associates K_TOKEN with the cryptographic module in a server- algorithms supported by the cryptographic module for the purposes of
side data store. The intent is that the data store later on this protocol.
will be used by some service that needs to verify or decrypt
data produced by the cryptographic module and the key. The DSKPP server responds to the DSKPP client with a
e. Once the association has been made, the DSKPP server sends a <KeyProvServerHello> message, whose content includes a random nonce,
R_S, along with information about the type of key to generate, and
the encryption algorithm chosen to protect sensitive data sent in the
protocol. The length of the nonce R_S may depend on the selected key
type. The <KeyProvServerHello> message also provides information
about either a shared secret key to use for encrypting the
cryptographic module's random nonce (see description of
<KeyProvClientNonce> below), or its own public key. Optionally,
<KeyProvServerHello> may include a MAC that the DSKPP client may use
for server authentication during key replacement.
4.3.1.2. Round-trip #2: <KeyProvClientNonce> and
<KeyProvServerFinished>
Based on information contained in the <KeyProvServerHello> message,
the cryptographic module generates a random nonce, R_C. The length of
the nonce R_C may depend on the selected key type. The cryptographic
module encrypts R_C using the selected encryption algorithm and with
a key, K, that is either the DSKPP server's public key, K_SERVER, or
a shared secret key, K_SHARED, as indicated by the DSKPP server. If
K is equivalent to K_SERVER, then the cryptographic module SHOULD
verify the server's certificate before using it to encrypt R_C in
accordance with [RFC3280]. The DSKPP client then sends the encrypted
random nonce to the DSKPP server in a <KeyProvClientNonce> message,
and may include client authentication data, such as a certificate or
MAC derived from an authentication code and R_C. Finally, the
cryptographic module calculates a symmetric key, K_TOKEN, of the
selected type from the combination of the two random nonces R_S and
R_C, the encryption key K, and possibly some other data, using the
DSKPP-PRF function defined in Section 5.1.
The DSKPP server decrypts R_C, calculates K_TOKEN from the
combination of the two random nonces R_S and R_C, the encryption key
K, and possibly some other data, using the DSKPP-PRF function defined
in Section 5.1. The server then associates K_TOKEN with the
cryptographic module in a server-side data store. The intent is that
the data store later on will be used by some service that needs to
verify or decrypt data produced by the cryptographic module and the
key.
Once the association has been made, the DSKPP server sends a
confirmation message to the DSKPP client called confirmation message to the DSKPP client called
<ServerFinished>. The confirmation message includes a key <KeyProvServerFinished>. Optionally, <KeyProvServerFinished> may
container that holds an identifier for the generated key (but include a MAC that the DSKPP client may use for server
not the key itself) and additional configuration information, authentication. The confirmation message includes a key container
e.g., the identity of the DSKPP server. Optionally, that holds an identifier for the generated key (but not the key
<ServerFinished> may include a MAC that the DSKPP client may itself) and additional configuration information, e.g., the identity
use for server authentication. of the DSKPP server. The default symmetric key container format that
f. Upon receipt of the DSKPP server's confirmation message, the is used in the <KeyProvServerFinished> message is based on the
cryptographic module associates the provided key container with Portable Symmetric Key Container (PSKC) defined in [PSKC].
the generated key K_TOKEN, and stores any provided Alternative formats MAY include PKCS#12 [PKCS-12] or PKCS#5 XML
configuration data. [PKCS-5-XML] format.
Note: Conceptually, although R_C is one pseudorandom string, it may
be viewed as consisting of two components, R_C1 and R_C2, where R_C1
is generated during the protocol run, and R_C2 can be pre-generated
and loaded on the cryptographic module before the device is issued to
the user. In that case, the latter string, R_C2, SHOULD be unique
for each cryptographic module.
The inclusion of the two random nonces R_S and R_C in the key Upon receipt of the DSKPP server's confirmation message, the
generation provides assurance to both sides (the cryptographic module cryptographic module associates the provided key container with the
and the DSKPP server) that they have contributed to the key's generated key K_TOKEN, and stores any provided configuration data.
randomness and that the key is unique. The inclusion of the
encryption key K ensures that no man-in-the-middle MAY be present, or
else the cryptographic module will end up with a key different from
the one stored by the legitimate DSKPP server.
Note: A man-in-the-middle (in the form of corrupt client software or 4.3.2. Generation of Symmetric Keys for Cryptographic Modules
a mistakenly contacted server) MAY present his own public key to the
cryptographic module. This will enable the attacker to learn the With 4-pass DSKPP, the symmetric key that is the target of
client's version of K_TOKEN. However, the attacker is not able to provisioning, is generated on-the-fly without being transferred
persuade the legitimate server to derive the same value for K_TOKEN, between the DSKPP client and DSKPP server. A sample data flow
since K_TOKEN is a function of the public key involved, and the depicting how this works followed by computational information are
attacker's public key must be different than the correct server's (or provided in the subsections below.
else the attacker would not be able to decrypt the information
received from the client). Therefore, once the attacker is no longer
"in the middle," the client and server will detect that they are "out
of synch" when they try to use their keys. In the case of encrypting
R_C with K_SERVER, it is therefore important to verify that K_SERVER
really is the legitimate server's key. One way to do this is to
independently validate a newly generated K_TOKEN against some
validation service at the server (e.g. by using a connection
independent from the one used for the key generation).
4.3.2.1. Data Flow
A sample data flow showing key generation during the 4-pass protocol
is shown in Figure 4.
+----------------------+ +-------+ +----------------------+ +----------------------+ +-------+ +----------------------+
| +------------+ | | | | | | +------------+ | | | | |
| | Server key | | | | | | | | Server key | | | | | |
| +<-| Public |------>------------->-------------+---------+ | | +<-| Public |------>------------->-------------+---------+ |
| | | Private | | | | | | | | | | | Private | | | | | | | |
| | +------------+ | | | | | | | | | +------------+ | | | | | | |
| | | | | | | | | | | | | | | | | | | |
| V V | | | | V V | | V V | | | | V V |
| | +---------+ | | | | +---------+ | | | | +---------+ | | | | +---------+ | |
| | | Decrypt |<-------<-------------<-----------| Encrypt | | | | | | Decrypt |<-------<-------------<-----------| Encrypt | | |
skipping to change at page 19, line 5 skipping to change at page 21, line 46
| +-------+ | | | | +-------+ | | +-------+ | | | | +-------+ |
| |Key Id |-------->------------->------|Key Id | | | |Key Id |-------->------------->------|Key Id | |
| +-------+ | | | | +-------+ | | +-------+ | | | | +-------+ |
+----------------------+ +-------+ +----------------------+ +----------------------+ +-------+ +----------------------+
DSKPP Server DSKPP Client DSKPP Client DSKPP Server DSKPP Client DSKPP Client
(PC Host) (cryptographic module) (PC Host) (cryptographic module)
Figure 4: Principal data flow for DSKPP key generation - Figure 4: Principal data flow for DSKPP key generation -
using public server key using public server key
4.2.2. Two-pass DSKPP Note: Conceptually, although R_C is one pseudorandom string, it may
be viewed as consisting of two components, R_C1 and R_C2, where R_C1
is generated during the protocol run, and R_C2 can be pre-generated
and loaded on the cryptographic module before the device is issued to
the user. In that case, the latter string, R_C2, SHOULD be unique
for each cryptographic module.
The inclusion of the two random nonces R_S and R_C in the key
generation provides assurance to both sides (the cryptographic module
and the DSKPP server) that they have contributed to the key's
randomness and that the key is unique. The inclusion of the
encryption key K ensures that no man-in-the-middle may be present, or
else the cryptographic module will end up with a key different from
the one stored by the legitimate DSKPP server.
Note: A man-in-the-middle (in the form of corrupt client software or
a mistakenly contacted server) may present his own public key to the
cryptographic module. This will enable the attacker to learn the
client's version of K_TOKEN. However, the attacker is not able to
persuade the legitimate server to derive the same value for K_TOKEN,
since K_TOKEN is a function of the public key involved, and the
attacker's public key must be different than the correct server's (or
else the attacker would not be able to decrypt the information
received from the client). Therefore, once the attacker is no longer
"in the middle," the client and server will detect that they are "out
of sync" when they try to use their keys. In the case of encrypting
R_C with K_SERVER, it is therefore important to verify that K_SERVER
really is the legitimate server's key. One way to do this is to
independently validate a newly generated K_TOKEN against some
validation service at the server (e.g. by using a connection
independent from the one used for the key generation).
4.3.2.2. Computing the Symmetric Key
In DSKPP, keys are generated using the DSKPP-PRF function defined in
Section 5.1, a secret random value R_C chosen by the DSKPP client, a
random value R_S chosen by the DSKPP server, and the key k used to
encrypt R_C. The input parameter s of DSKPP-PRF is set to the
concatenation of the (ASCII) string "Key generation", k, and R_S, and
the input parameter dsLen is set to the desired length of the key,
K_TOKEN (the length of K_TOKEN is given by the key's type):
dsLen = (desired length of K_TOKEN)
K_TOKEN = DSKPP-PRF (R_C, "Key generation" || k || R_S, dsLen)
When computing K_TOKEN above, the output of DSKPP-PRF MAY be subject
to an algorithm-dependent transform before being adopted as a key of
the selected type. One example of this is the need for parity in DES
keys.
4.3.3. Client Authentication
To ensure that a generated key K_TOKEN ends up associated with the
correct cryptographic module and user, the DSKPP client using any of
the methods described in Section 5.3. Whatever the method, the DSKPP
server MUST ensure that a generated key is associated with the
correct cryptographic module, and if applicable, the correct user.
4.3.4. Key Confirmation
In four-pass DSKPP, the client includes a nonce R_C in the
<KeyProvClientHello> message. The MAC value in the
<KeyProvServerFinished> message MUST be computed on the (ASCII)
string "MAC 2 computation", the client nonce R_C using a MAC key
K_MAC. This key MUST be generated together with K_TOKEN using R_C
and R_S.
The MAC value in <KeyProvServerFinished> MAY be computed by using the
DSKPP-PRF function of Section 5.1, in which case the input parameter
s MUST consist of the concatenation of the (ASCII) string "MAC 2
computation", R_C, the parameter dsLen MUST be set to the length of
R_C:
dsLen = len(R_C)
MAC = DSKPP-PRF (K_MAC, "MAC 2 computation" || R_C, dsLen)
4.3.5. Server Authentication
A DSKPP server MUST authenticate itself to avoid a false "Commit" of
a symmetric key that which could cause the cryptographic module to
end up in an initialized state for which the server does not know the
stored key. To do this, the DSKPP server authenticates itself by
including a MAC value in the <KeyProvServerHello> message when
replacing a existing key. The MAC value is generated using the
existing the MAC key K_MAC' (the MAC key that existed before this
protocol run). The MAC algorithm MUST be the same as the algorithm
used for key confirmation purposes. In addition, a DSKPP server can
leverage transport layer authentication if it is available.
When the MAC value is used for server authentication, the value MAY
be computed by using the DSKPP-PRF function of Section 5.1, in which
case the input parameter s MUST be set to the concatenation of the
(ASCII) string "MAC 1 computation", R (if sent by the client), and
R_S, and k MUST be set to the existing MAC key K_MAC' . The input
parameter dsLen MUST be set to the length of R_S:
dsLen = len(R_S)
MAC = DSKPP-PRF (K_MAC', "MAC 1 computation" || [R ||] R_S, dsLen)
4.4. Two-Pass Protocol Usage
The 2-pass protocol flow is suitable for environments wherein near The 2-pass protocol flow is suitable for environments wherein near
real-time communication between the DSKPP client and server may not real-time communication between the DSKPP client and server may not
be possible. It is also suitable for environments wherein be possible. It is also suitable for environments wherein
administrative approval is a required step in the flow, and for administrative approval is a required step in the flow, and for
provisioning of pre-generated keys. In the 2-pass protocol flow, provisioning of pre-generated keys. In the 2-pass protocol flow, the
shown in Figure 5, the client's initial <ClientHello> message is client's initial <KeyProvClientHello> message is directly followed by
directly followed by a <ServerFinished> message. There is no a <KeyProvServerFinished> message. There is no exchange of the
exchange of the <ServerHello> message or the <ClientNonce> message. <KeyProvServerHello> message or the <KeyProvClientNonce> message.
However, as the two-pass variant of DSKPP consists of one round trip However, as the two-pass variant of DSKPP consists of one round trip
to the server, the client is still able to include its random nonce, to the server, the client is still able to include its random nonce,
R_C, algorithm preferences and supported key types in the R_C, algorithm preferences and supported key types in the
<ClientHello> message. Note than by including R_C in <ClientHello>, <KeyProvClientHello> message. Note that by including R_C in
the DSKPP client is able to ensure the server is alive before <KeyProvClientHello>, the DSKPP client is able to ensure the server
"commiting" the key. Also note that the DSKPP "trigger" message MAY is alive before "committing" the key. Also note that the DSKPP
be used to trigger the client's sending of the <ClientHello> message. "trigger" message MAY be used to trigger the client's sending of the
<KeyProvClientHello> message.
Essentially, two-pass DSKPP is a transport of key material from the Essentially, two-pass DSKPP is a transport of key material from the
DSKPP server to the DSKPP client. Two-pass DSKPP supports multiple DSKPP server to the DSKPP client. Two-pass DSKPP supports multiple
key initialization methods that ensure K_TOKEN is not exposed to any key initialization methods that ensure K_TOKEN is not exposed to any
other entity than the DSKPP server and the cryptographic module other entity than the DSKPP server and the cryptographic module
itself. Currently, three such key initialization methods are defined itself. Currently, three such key initialization methods are defined
(refer to Appendix A), each supporting a different usage of 2-pass (refer to Section 11), each supporting a different usage of 2-pass
DSKPP: DSKPP:
Key Transport This profile is intended for PKI-capable Key Transport This profile is intended for PKI-capable
devices. Key transport is carried out devices. Key transport is carried out
using a public key, K_CLIENT, whose using a public key, K_CLIENT, whose
private key part resides in the private key part resides in the
cryptographic module as the transport cryptographic module as the transport
key. key.
Key Wrap This profile is ideal for pre-keyed Key Wrap This profile is ideal for pre-keyed
devices, e.g., SIM cards. Key wrap is devices, e.g., SIM cards. Key wrap is
carried out using a symmetric key- carried out using a symmetric key-
wrapping key, K_SHARED, which is known in wrapping key, K_SHARED, which is known in
advance by both the cryptographic module advance by both the cryptographic module
and the DSKPP server. and the DSKPP server.
Passphrase-based Key Wrap This profile is a variation of the Key Passphrase-Based Key Wrap This profile is a variation of the Key
Wrap Profile. It is applicable to Wrap Profile. It is applicable to
constrained devices with keypads, e.g., constrained devices with keypads, e.g.,
mobile phones. Key wrap is carried out mobile phones. Key wrap is carried out
using a passphrase-derived key-wrapping using a passphrase-derived key-wrapping
key, K_DERIVED, which is known in advance key, K_DERIVED, which is known in advance
by both the cryptographic module and by both the cryptographic module and
DSKPP server. DSKPP server.
+---------------+ +---------------+ The full 2-pass protocol exchange when the key is transported using
| | | | the client public key is as follows:
| DSKPP client | | DSKPP server |
| | | |
+---------------+ +---------------+
| |
| [ <---- DSKPP trigger ----- ] |
| |
| ------- Client Hello -------> |
| |
| <----- Server Finished ------ |
| |
Figure 5: The 2-pass DSKPP protocol (with OPTIONAL preceding trigger) [<Trigger>]:
a. The DSKPP client sends a <ClientHello> message to the DSKPP [ID_Device], [ID_K], [URL_S],[R_S]
server. The message provides the client nonce, R_C, and
<KeyProvClientHello>:
[ID_Device], ID_K, R_S, R_C, AUTHDATA, Alg_List
<KeyProvServerFinished>:
ENC_K_CLIENT ( K_TOKEN || K_MAC)), K_CONFDATA, ID_S, DSKPP-
PRF_K_MAC("MAC 1 Computation" || ID_S || R_C, len(R_C) ), [ DSKPP-
PRF_K_MAC'("MAC 1 Computation" || ID_S || R_C), 16]
The full 2-pass protocol exchange when the key is wrapped using a
shared key is as follows:
[<Trigger>]:
[ID_Device], [ID_K], [URL_S],[R_S]
<KeyProvClientHello>:
[ID_Device], ID_K, R_S, R_C, AUTHDATA, Alg_List
<KeyProvServerFinished>:
ENC_K_SHARED(K_TOKEN || K_MAC), K_CONFDATA, ID_S, DSKPP-
PRF_K_MAC("MAC 1 Computation" || ID_S || R_C), [ DSKPP-
PRF_K_MAC'("MAC 1 Computation "|| ID_S||R_C)]
The full 2-pass protocol when the key is wrapped using a passphrase
based derived key is as follows:
[<Trigger>]:
[ID_Device], [ID_K], [URL_S],[R_S]
<KeyProvClientHello>:
[ID_Device], ID_K, R_S, R_C, AUTHDATA, Alg_List
<KeyProvServerFinished>:
ENC_K_DERIVED(K_TOKEN || K_MAC), K_CONFDATA, ID_S, DSKPP-
PRF_K_MAC("MAC 1 Computation" || ID_S || R_C), [ DSKPP-
PRF_K_MAC'("MAC 1 Computation" || ID_S || R_C)]
The following subsections describe these exchanges in more detail.
4.4.1. Message Flow
The 2-pass protocol flow consists of one round trip between the DSKPP
client and DSKPP server, which consists of two "passes", i.e., one
request message and one response message:
Round-trip #1: Pass 1=<KeyProvClientHello>, Pass
2=<KeyProvServerFinished>
a. The DSKPP client sends a <KeyProvClientHello> message to the
DSKPP server. The message provides the client nonce, R_C, and
information about the DSKPP versions, protocol variants, key information about the DSKPP versions, protocol variants, key
types, encryption and MAC algorithms supported by the types, encryption and MAC algorithms supported by the
cryptographic module for the purposes of this protocol. The cryptographic module for the purposes of this protocol. The
message may also include client authentication data, such as a message may also include client authentication data, such as
certificate or authentication code. Unlike 4-pass DSKPP, device certificate or MAC derived from authentication code and
2-pass DSKPP client uses the <ClientHello> message to declare R_C. Authentication code is sent in clear only when underlying
which key initialization method it supports, providing required transport layer can ensure data confidentiality. Unlike 4-pass
payload information, e.g., K_CLIENT for the Key Transport DSKPP, 2-pass DSKPP client uses the <KeyProvClientHello> message
Profile. to declare which key initialization method it supports, providing
required payload information, e.g., K_CLIENT for the Key
Transport Profile.
b. The DSKPP server generates a key K from which two keys, K_TOKEN b. The DSKPP server generates a key K from which two keys, K_TOKEN
and K_MAC are derived. K is either transported or wrapped in and K_MAC are derived. (Alternatively, the key K may have been
accordance with the key initialization method specified by the pre-generated as described in Section 3.1. K is either
DSKPP client in the <ClientHello> message. The server then transported or wrapped in accordance with the key initialization
associates K_TOKEN with the cryptographic module in a server- method specified by the DSKPP client in the <KeyProvClientHello>
side data store. The intent is that the data store later on message. The server then associates K_TOKEN with the
will be used by some service that needs to verify or decrypt cryptographic module in a server-side data store. The intent is
data produced by the cryptographic module and the key. that the data store later on will be used by some service that
needs to verify or decrypt data produced by the cryptographic
module and the key.
c. Once the association has been made, the DSKPP server sends a c. Once the association has been made, the DSKPP server sends a
confirmation message to the DSKPP client called confirmation message to the DSKPP client called
<ServerFinished>. The confirmation message includes a key <KeyProvServerFinished>. The confirmation message includes a key
container that holds an identifier for the key, the key K from container that holds an identifier for the key, the key K from
which K_TOKEN and K_MAC are derived, and additional which K_TOKEN and K_MAC are derived, and additional configuration
configuration information (note that the latter MUST include information (note that the latter MUST include the identity of
the identity of the DSKPP server for authentication purposes). the DSKPP server for authentication purposes). In addition,
In addition, <ServerFinished> MUST include two MACs whose <KeyProvServerFinished> MUST include two MACs whose values are
values are calculated with contribution from the client nonce, calculated with contribution from the client nonce, R_C, provided
R_C, provided in the <ClientHello> message. The MAC values in the <KeyProvClientHello> message. The data will allow the
will allow the cryptographic module to perform key confirmation cryptographic module to perform key confirmation and server
and server authentication before "commiting" the key. authentication before "committing" the key. Note that the second
MAC value that is intended for key confirmation MAY only be used
for replacing and existing key.
d. Upon receipt of the DSKPP server's confirmation message, the d. Upon receipt of the DSKPP server's confirmation message, the
cryptographic module extracts the key data from the provided cryptographic module extracts the key data from the provided key
key container, uses the two MAC values to perform key container, uses the provided MAC values to perform key
confirmation and server authentication, and stores the key confirmation and server authentication, and stores the key
material locally. material locally.
4.2.3. One-pass DSKPP 4.4.2. Key Confirmation
In two-pass DSKPP, the client is REQUIRED to include a nonce R in the
<KeyProvClientHello> message. Further, the server is REQUIRED to
include an identifier, ID_S, for itself (via the key container) in
the <KeyProvServerFinished> message. The MAC value in the
<KeyProvServerFinished> message MUST be computed on the (ASCII)
string "MAC 1 computation", the server identifier ID_S, and R using a
MAC key K_MAC. This key MUST be provided together with K_TOKEN to
the cryptographic module.
If DSKPP-PRF is used as the MAC algorithm, then the input parameter s
MUST consist of the concatenation of the (ASCII) string "MAC 1
computation" and R, and the parameter dsLen MUST be set to the length
of R:
dsLen = len(R)
MAC = DSKPP-PRF (K_MAC, "MAC 1 computation" || ID_S || R, dsLen)
4.4.3. Server Authentication
A server MUST authenticate itself when attempting to replace an
existing K_TOKEN. In 2-pass DSKPP, servers authenticate themselves
by including a second MAC value in the AuthenticationDataType element
of <KeyProvServerFinished>. The MAC value in the
AuthenticationDataType element MUST be computed on the (ASCII) string
"MAC 1 computation", the server identifier ID_S, and R, using the
existing MAC key K_MAC' (the MAC key that existed before this
protocol run). The MAC algorithm MUST be the same as the algorithm
used for key confirmation purposes.
If DSKPP-PRF is used as the MAC algorithm, then the input parameter s
MUST consist of the concatenation of the (ASCII) string "MAC 1
computation" ID_S, and R. The parameter dsLen MUST be set to at least
16 (i.e. the length of the MAC MUST be at least 16 octets):
dsLen >= 16
MAC = DSKPP-PRF (K_MAC', "MAC 1 computation" || ID_S || R, dsLen)
4.5. One-Pass Protocol Usage
The one-pass protocol flow is suitable for environments wherein near The one-pass protocol flow is suitable for environments wherein near
real-time communication between the DSKPP client and server may not real-time communication between the DSKPP client and server may not
be possible. It is also suitable for environments wherein be possible. It is also suitable for environments wherein
administrative approval is a required step in the flow, and for administrative approval is a required step in the flow, and for
provisioning of pre-generated keys. In one-pass DSKPP, shown in provisioning of pre-generated keys. In one-pass DSKPP, the server
Figure 6, the server simply sends a <ServerFinished> message to the simply sends a <KeyProvServerFinished> message to the DSKPP client.
DSKPP client. In this case, there is no exchange of the In this case, there is no exchange of the <KeyProvClientHello>,
<ClientHello>, <ServerHello>, and <ClientNonce> DSKPP messages, and <KeyProvServerHello>, and <KeyProvClientNonce> DSKPP messages, and
hence there is no way for the client to express supported algorithms hence there is no way for the client to express supported algorithms
or key types. Before attempting one-pass DSKPP, the server MUST or key types. Before attempting one-pass DSKPP, the server MUST
therefore have prior knowledge not only that the client is able and therefore have prior knowledge not only that the client is able and
willing to accept this variant of DSKPP, but also of algorithms and willing to accept this variant of DSKPP, but also of algorithms and
key types supported by the client. key types supported by the client.
Essentially, one-pass DSKPP is a transport of key material from the Essentially, one-pass DSKPP is a transport of key material from the
DSKPP server to the DSKPP client. As with two-pass DSKPP, the one- DSKPP server to the DSKPP client. As with two-pass DSKPP, the one-
pass variant relies on key initialization methods that ensure K_TOKEN pass variant relies on key initialization methods that ensure K_TOKEN
is not exposed to any other entity than the DSKPP server and the is not exposed to any other entity than the DSKPP server and the
cryptographic module itself. The same key initialization profiles cryptographic module itself. The same key initialization profiles
are defined as described in Section 4.2.2 and Appendix A. are defined as described in Section 4.4 and Section 11.
Outside the specific cases where one-pass DSKPP is desired, clients Outside the specific cases where one-pass DSKPP is desired, clients
SHOULD be constructed and configured to only accept DSKPP server SHOULD be constructed and configured to only accept DSKPP server
messages in response to client-initiated transactions. messages in response to client-initiated transactions.
+---------------+ +---------------+ The 1-pass protocol when the key is transported using the client
| | | | public Key is as follows:
| DSKPP client | | DSKPP server |
| | | |
+---------------+ +---------------+
| |
| <----- Server Finished ------ |
| |
Figure 6: The 1-pass DSKPP protocol
a. The DSKPP server generates a key K from which two keys, K_TOKEN
and K_MAC are derived. K is either transported or wrapped in
accordance with the key initialization method known in advance
by the DSKPP server. The server then associates K_TOKEN with
the cryptographic module in a server-side data store. The
intent is that the data store later on will be used by some
service that needs to verify or decrypt data produced by the
cryptographic module and the key.
b. Once the association has been made, the DSKPP server sends a
confirmation message to the DSKPP client called
<ServerFinished>. The confirmation message includes a key
container that holds an identifier for the key, the key K from
which K_TOKEN and K_MAC are derived, and additional
configuration information (note that the latter MUST include
the identity of the DSKPP server for authentication purposes).
In addition, <ServerFinished> MUST include two MACs, which will
allow the cryptographic module to perform key confirmation and
server authentication before "commiting" the key. Note that
unlike two-pass DSKPP, in the one-pass variant, the server does
not have the client nonce, R_C, and therefore the MACs values
are calculated with contribution from an unsigned integer, I,
generated by the server during the protocol run.
c. Upon receipt of the DSKPP server's confirmation message, the
cryptographic module extracts the key data from the provided
key container, uses the two MAC values to perform key
confirmation and server authentication, and stores the key
material locally.
4.3. Authentication
4.3.1. Client Authentication (Applicable to Four- and Two-Pass DSKPP)
To ensure that a generated K_TOKEN ends up associated with the
correct cryptographic module and user, the DSKPP server MAY couple an
initial user authentication to the DSKPP execution in several ways,
as discussed in the following sub-sections. Whatever the method, the
DSKPP server MUST ensure that a generated key is associated with the
correct cryptographic module, and if applicable, the correct user.
For a further discussion of this, and threats related to man-in-the-
middle attacks in this context, see Section 7.
4.3.1.1. Device Certificate
Instead of requiring an Authentication Code for in-band <KeyProvServerFinished>:
authentication, a device certificate could be used, which was
supplied with the cryptographic module by its issuer.
4.3.1.2. Device Identifier ENC_K_CLIENT ( K_TOKEN || K_MAC)), K_CONFDATA, DSKPP-PRF_K_MAC
("MAC 1 Computation" || ID_S || I), [ DSKPP-PRF_K_MAC'("MAC 2
Computation"||ID_S||I')]
The provisioning server could be pre-configured with a device The 1-pass protocol when the key is wrapped using a shared key is as
identifier. The DSKPP server MAY then include this identifier in the follows:
DSKPP initialization trigger, and the DSKPP client would include it
in its message(s) to the DSKPP server for authentication. Note that
it is also legitimate for a DSKPP client to initiate the DSKPP
protocol run without having received an initialization message from a
server, but in this case any provided device identifier MUST NOT be
accepted by the DSKPP server unless the server has access to a unique
key for the identified device and that key will be used in the
protocol.
4.3.1.3. One-time Use Authentication Code <KeyProvServerFinished>:
A key issuer may provide a one-time value, called an Authentication ENC_K_SHARED (K_TOKEN || K_MAC), K_CONFDATA, DSKPP-PRF_K_MAC("MAC
Code, to the user or device out-of-band and require this value to be 1 Computation" || ID_S || I), [ PRF_K_MAC'("MAC 2 Computation" ||
used by the DSKPP client when contacting the DSKPP server. The DSKPP ID_S || I')]
client MAY include the authentication data in its <ClientHello> (and
<ClientNonce> for four-pass) message, and the DSKPP server MUST
verify the data before continuing with the protocol run. Note: An
alternate method for getting the Authentication Code to the client,
is for the DSKPP server to place the value in the <TriggerNonce>
element of the DSKPP initialization trigger (if triggers are used;
see Section 5.2.7) .
+------------+ Get Authentication Code +------------+ The 1-pass protocol when the key is wrapped using a passphrase
| User |<------------------------->| Issuer | derived key is as follows:
+------------+ +------------+
| |
| |
| |
V V
+--------------+ +--------------+
| Provisioning | Authentication Data | Provisioning |
| Client |----------------------->| Server |
+--------------+ +--------------+
Figure 7: User Authentication with One-Time Code <KeyProvServerFinished>:
Considering an Authentication Code as a special form of shared secret ENC_K_DERIVED(K_TOKEN || K_MAC), K_CONFDATA, DSKPP-PRF_K_MAC("MAC
between a user and a provisioning server, Authentication Data can 1 Computation" || ID_S || I), [DSKPP-PRF_K_MAC'("MAC 2
have one of the following forms: Computation" || ID_S || I')]
o AuthenticationData = Hash (Authentication Code) The subsections below describe the 1-pass protocol in more detail.
When an Authentication Code is used to initiate the protocol run,
the Authentication Code MUST be sent to the DSKPP server in a
secure manner. If the underlying transport channel is secure, the
authentication data MAY contain the plaintext format or the hashed
format of the Authentication Code using a hash function.
o AuthenticationData = HMAC(Authentication Code, K_AUTH) 4.5.1. Message Flow
If the underlying transport is not secure, the client MUST use a The 1-pass protocol flow consists of one "pass", i.e., a single
key K_AUTH and the Authentication Code to derive authentication message sent from the DSKPP server to the DSKPP client:
data. For example, if the Authentication Code has a fixed format,
e.g.,
AuthenticationCode = passwordLength || ID || password || checksum Pass 1: <KeyProvServerFinished>
then AuthenticationData MAY be calculated as follows: a. The DSKPP server generates a key K from which two keys, K_TOKEN
and K_MAC are derived. K is either transported or wrapped in
accordance with the key initialization method known in advance by
the DSKPP server. The server then associates K_TOKEN with the
cryptographic module in a server-side data store. The intent is
that the data store later on will be used by some service that
needs to verify or decrypt data produced by the cryptographic
module and the key.
b. Once the association has been made, the DSKPP server sends a
confirmation message to the DSKPP client called
<KeyProvServerFinished>. The confirmation message includes a key
container that holds an identifier for the key, the key K from
which K_TOKEN and K_MAC are derived, and additional configuration
information (note that the latter MUST include the identity of
the DSKPP server for authentication purposes). In addition,
<KeyProvServerFinished> MUST include two MACs, which will allow
the cryptographic module to perform key confirmation and server
authentication before "commuting" the key. Note that unlike two-
pass DSKPP, in the one-pass variant, the server does not have the
client nonce, R_C, and therefore the MACs values are calculated
with contribution from an unsigned integer, I, generated by the
server during the protocol run.
AuthenticationData = AuthenticationCode->ID || B64(Digest) c. Upon receipt of the DSKPP server's confirmation message, the
cryptographic module extracts the key data from the provided key
container, uses the two MAC values to perform key confirmation
and server authentication, and stores the key material locally.
where for four-pass DSKPP, the cryptographic module uses the 4.5.2. Key Confirmation
server nonce R_S in combination with the server URL to calculate
the Digest:
Digest = DSKPP-PRF-AES(K_AUTH, AuthCode->ID || serverURL || R_S, In one-pass DSKPP, the server MUST include an identifier, ID_S, for
16) itself (via the key container) in the <KeyProvServerFinished>
message. The MAC value in the <KeyProvServerFinished> message MUST
be computed on the (ASCII) string "MAC 1 computation", the server
identifier ID_S, and an unsigned integer value I, using a MAC key
K_MAC. The value I MUST be monotonically increasing and guaranteed
not to be used again by this server towards this cryptographic
module. It could for example be the number of seconds since some
point in time with sufficient granularity, a counter value, or a
combination of the two where the counter value is reset for each new
time value. In contrast to the MAC calculation in four-pass DSKPP,
the MAC key K_MAC MUST be provided together with K_TOKEN to the
cryptographic module.
Refer to Section 4.5 for a description of DSKPP-PRF in general and Note: The integer I does not necessarily need to be maintained by the
Appendix E for a description of DSKPP-PRF-AES. DSKPP server on a per cryptographic module basis (it is enough if the
server can guarantee that the same value is never being sent twice to
the same cryptographic module).
For two-pass DSKPP, the cryptographic module does not have access If DSKPP-PRF is used as the MAC algorithm, then the input parameter s
to the server nonce R_S in combination and so: MUST consist of the concatenation of the (ASCII) string "MAC 1
computation", ID_S, and I. The parameter dsLen MUST be set to at
least 16 (i.e. the length of the MAC MUST be at least 16 octets):
Digest = DSKPP-PRF-AES(K_AUTH, AuthenticationCode->ID || dsLen >= 16
serverURL, 16)
In either case, K_AUTH MAY be derived AES key from MAC = DSKPP-PRF (K_MAC, "MAC 1 computation" || ID_S || I, dsLen)
AuthenticationCode->password as in:
K_AUTH = truncate( Hash( Hash(...n times...( AuthCode->password ) The server MUST provide I to the client in the Nonce attribute of the
) ) ) <Mac> element of the <KeyProvServerFinished> message using the
AuthenticationCodeMacType defined in Section 6.2.2.4.
where truncate() returns the first 16 bytes from the result of the 4.5.3. Server Authentication
last hash iteration, and n is the number of hash iterations (set
to fixed values, e.g., between 10 and 100).
o AuthenticationData = <Signed data with a client certificate> As discussed in , servers need to authenticate themselves when
attempting to replace an existing K_TOKEN. In 1-pass DSKPP, servers
authenticate themselves by including a second MAC value in the
AuthenticationDataType element of <KeyProvServerFinished>. The MAC
value in the AuthenticationDataType element MUST be computed on the
(ASCII) string "MAC 1 computation", the server identifier ID_S, and a
new value I', I' > I, using the existing MAC key K_MAC' (the MAC key
that existed before this protocol run). The MAC algorithm MUST be
the same as the algorithm used for key confirmation purposes.
When a certificate is used for authentication, the authentication If DSKPP-PRF is used as the MAC algorithm, then the input parameter s
data MAY be client-signed. Authentication data MAY be omitted if MUST consist of the concatenation of the (ASCII) string "MAC 1
client certificate authentication has been provided by the computation" ID_S, and I'. The parameter dsLen MUST be set to at
transport channel such as TLS. least 16 (i.e. the length of the MAC MUST be at least 16 octets):
When an issuer delegates symmetric key provisioning to a third party dsLen >= 16
provisioning service provider, both client authentication and issuer
authentication are required by the provisioning server. Client
authentication to the Issuer MAY be in-band or out-of-band as
described above. The issuer acts as a proxy for the provisioning
server. The issuer authenticates to the provisioning service
provider either using a certificate or a pre-established secret key.
4.3.2. Server Authentication MAC = DSKPP-PRF (K_MAC', "MAC 1 computation" || ID_S || I', dsLen)
A DSKPP server MUST authenticate itself to avoid a false "Commit" of The server MUST provide I' to the client in the Nonce attribute of
a symmetric key that which could cause the cryptographic module to the <Mac> element of the AuthenticationDataType extension. If the
end up in an initialized state for which the server does not know the protocol run is successful, the client stores I' as the new value of
stored key. To do this, the DSKPP server authenticates itself by I for this server.
including a MAC in each of its responses to the client. In 2-pass
and 1-pass DSKPP, servers authenticate themselves by including a
second MAC value in the response message. In addition, a DSKPP
server can leverage transport layer authentication if it is
available.
4.4. Symmetric Key Container Format 5. Methods Common to More Than One Protocol Variant
The default symmetric key container format that is used in the The mechanisms contained in this section are used in more than one
<ServerFinished> message is based on the Portable Symmetric Key variant of DSKPP.
Container (PSKC) defined in [PSKC]. Alternative formats MAY include
PKCS#12 [PKCS-12] or PKCS#5 XML [PKCS-5-XML] format.
4.5. The DSKPP One-Way Pseudorandom Function, DSKPP-PRF 5.1. The DSKPP One-Way Pseudorandom Function, DSKPP-PRF
4.5.1. Introduction 5.1.1. Introduction
The general requirements on DSKPP-PRF are the same as on keyed hash All of the protocol variants depend on DSKPP-PRF. The general
functions: It MUST take an arbitrary length input, and be one-way and requirements on DSKPP-PRF are the same as on keyed hash functions: It
collision-free (for a definition of these terms, see, e.g., [FAQ]). MUST take an arbitrary length input, and be one-way and collision-
Further, the DSKPP-PRF function MUST be capable of generating a free (for a definition of these terms, see, e.g., [FAQ]). Further,
variable-length output, and its output MUST be unpredictable even if the DSKPP-PRF function MUST be capable of generating a variable-
other outputs for the same key are known. length output, and its output MUST be unpredictable even if other
outputs for the same key are known.
It is assumed that any realization of DSKPP-PRF takes three input It is assumed that any realization of DSKPP-PRF takes three input
parameters: A secret key k, some combination of variable data, and parameters: A secret key k, some combination of variable data, and
the desired length of the output. The combination of variable data the desired length of the output. The combination of variable data
can, without loss of generalization, be considered as a salt value can, without loss of generalization, be considered as a salt value
(see PKCS#5 Version 2.0 [PKCS-5], Section 4), and this (see PKCS#5 Version 2.0 [PKCS-5], Section 4), and this
characterization of DSKPP-PRF SHOULD fit all actual PRF algorithms characterization of DSKPP-PRF SHOULD fit all actual PRF algorithms
implemented by cryptographic modules. From the point of view of this implemented by cryptographic modules. From the point of view of this
specification, DSKPP-PRF is a "black-box" function that, given the specification, DSKPP-PRF is a "black-box" function that, given the
inputs, generates a pseudorandom value. inputs, generates a pseudorandom value.
Separate specifications MAY define the implementation of DSKPP-PRF Separate specifications MAY define the implementation of DSKPP-PRF
for various types of cryptographic modules. Appendix E contains two for various types of cryptographic modules. Appendix B contains two
example realizations of DSKPP-PRF. example realizations of DSKPP-PRF.
4.5.2. Declaration 5.1.2. Declaration
DSKPP-PRF (k, s, dsLen) DSKPP-PRF (k, s, dsLen)
Input: Input:
k secret key in octet string format k secret key in octet string format
s octet string of varying length consisting of variable data s octet string of varying length consisting of variable data
distinguishing the particular string being derived distinguishing the particular string being derived
dsLen desired length of the output dsLen desired length of the output
Output: Output:
DS pseudorandom string, dsLen-octets long DS pseudorandom string, dsLen-octets long
For the purposes of this document, the secret key k MUST be 16 octets For the purposes of this document, the secret key k MUST be at least
long. 16 octets long.
4.6. Generation of Symmetric Keys for Cryptographic Modules
In DSKPP, keys are generated using the DSKPP-PRF function, a secret
random value R_C chosen by the DSKPP client, a random value R_S
chosen by the DSKPP server, and the key k used to encrypt R_C. The
input parameter s of DSKPP-PRF is set to the concatenation of the
(ASCII) string "Key generation", k, and R_S, and the input parameter
dsLen is set to the desired length of the key, K_TOKEN (the length of
K_TOKEN is given by the key's type):
dsLen = (desired length of K_TOKEN)
K_TOKEN = DSKPP-PRF (R_C, "Key generation" || k || R_S, dsLen)
When computing K_TOKEN above, the output of DSKPP-PRF MAY be subject
to an algorithm-dependent transform before being adopted as a key of
the selected type. One example of this is the need for parity in DES
keys.
4.7. Encryption of Pseudorandom Nonces Sent from the DSKPP Client 5.2. Encryption of Pseudorandom Nonces Sent from the DSKPP Client
(Applicable to Four-Pass and Two-Pass DSKPP)
DSKPP client random nonce(s) are either encrypted with the public key During 4- and 2-pass message exchanges, DSKPP client random nonce(s)
provided by the DSKPP server or by a shared secret key. For example, are either encrypted with the public key provided by the DSKPP server
in the case of a public RSA key, an RSA encryption scheme from PKCS or by a shared secret key. For example, in the case of a public RSA
#1 [PKCS-1] MAY be used. key, an RSA encryption scheme from PKCS #1 [PKCS-1] MAY be used.
In the case of a shared secret key, to avoid dependence on other In the case of a shared secret key, to avoid dependence on other
algorithms, the DSKPP client MAY use the DSKPP-PRF function described algorithms, the DSKPP client MAY use the DSKPP-PRF function described
herein with the shared secret key K_SHARED as input parameter k (in herein with the shared secret key K_SHARED as input parameter k (in
this case, K_SHARED SHOULD be used solely for this purpose), the this case, K_SHARED SHOULD be used solely for this purpose), the
concatenation of the (ASCII) string "Encryption" and the server's concatenation of the (ASCII) string "Encryption" and the server's
nonce R_S as input parameter s, and dsLen set to the length of R_C: nonce R_S as input parameter s, and dsLen set to the length of R_C:
dsLen = len(R_C) dsLen = len(R_C)
DS = DSKPP-PRF(K_SHARED, "Encryption" || R_S, dsLen) DS = DSKPP-PRF(K_SHARED, "Encryption" || R_S, dsLen)
This will produce a pseudorandom string DS of length equal to R_C. This will produce a pseudorandom string DS of length equal to R_C.
Encryption of R_C MAY then be achieved by XOR-ing DS with R_C: Encryption of R_C MAY then be achieved by XOR-ing DS with R_C:
Enc-R_C = DS ^ R_C Enc-R_C = DS ^ R_C
The DSKPP server will then perform the reverse operation to extract The DSKPP server will then perform the reverse operation to extract
R_C from Enc-R_C. R_C from Enc-R_C.
Note: It may appear that an attacker, who learns a previous value of 5.3. Client Authentication Mechanisms (Applicable to Four- and Two-Pass
R_C, may be able to replay the corresponding R_S and, hence, learn a DSKPP)
new R_C as well. However, this attack is mitigated by the
requirement for a server to show knowledge of K_AUTH (see below) in
order to successfully complete a key re-generation.
4.8. MAC calculations To ensure that a generated K_TOKEN ends up associated with the
correct cryptographic module and user, the DSKPP server MAY couple an
initial user authentication to the DSKPP execution in several ways,
as discussed in the following sub-sections. Whatever the method, the
DSKPP server MUST ensure that a generated key is associated with the
correct cryptographic module, and if applicable, the correct user.
For a further discussion of this, and threats related to man-in-the-
middle attacks in this context, see Section 14.
4.8.1. Four-pass DSKPP 5.3.1. Device Certificate
4.8.1.1. Server Authentication: <ServerHello> Instead of requiring an Authentication Code for in-band
authentication, a device private key and certificate could be used,
which was supplied with the cryptographic module by its issuer for
client authentication at the transport layer e.g TLS/HTTPS. When the
Device certificate is available and client authentication is not
provided in the transport layer, the DSKPP client may include a
device's certificate signed data for the authentication data.
The MAC value MUST be computed on the (ASCII) string "MAC 1 5.3.2. Device Identifier
computation", the client's nonce R (if sent), and the server's nonce
R_S using an authentication key K_AUTH that SHOULD be a special
authentication key used only for this purpose but MAY be the current
K_TOKEN.
The MAC value MAY be computed by using the DSKPP-PRF function of The DSKPP server could be pre-configured with a unique device
Section 4.5, in which case the input parameter s MUST be set to the identifier corresponding to a particular cryptographic module. The
concatenation of the (ASCII) string "MAC 1 computation", R (if sent DSKPP server MAY then include this identifier in the DSKPP
by the client), and R_S, and k MUST be set to K_AUTH. The input initialization trigger, and the DSKPP client would include it in its
parameter dsLen MUST be set to the length of R_S: message(s) to the DSKPP server for authentication. Note that it is
also legitimate for a DSKPP client to initiate the DSKPP protocol run
without having received an initialization message from a server, but
in this case any provided device identifier MUST NOT be accepted by
the DSKPP server unless the server has access to a unique key for the
identified device and that key will be used in the protocol.
dsLen = len(R_S) 5.3.3. Authentication Code
MAC = DSKPP-PRF (K_AUTH, "MAC 1 computation" || [R ||] R_S, dsLen) As shown in Figure 5, a key issuer may provide a one-time value,
called an Authentication Code, to the user or device out-of-band and
require this value to be used by the DSKPP client when contacting the
DSKPP server. The DSKPP client MAY include the authentication data
in its <KeyProvClientHello> (and <KeyProvClientNonce> for four-pass)
message, and the DSKPP server MUST verify the data before continuing
with the protocol run.
4.8.1.2. Server Authentication: <ServerFinished> Note: An alternate method for getting the Authentication Code to the
client, is for the DSKPP server to place the value in the
<TriggerNonce> element of the DSKPP initialization trigger (if
triggers are used; see Section 12.2.7) . When this method is used, a
transport providing privacy and integrity MUST be used to deliver the
DSKPP initialization trigger from the DSKPP server to the DSKPP
client, e.g. HTTPS.
The MAC value MUST be computed on the (ASCII) string "MAC 2 +------------+ Get Authentication Code +------------+
computation" and R_C using an authentication key K_AUTH. Again, this | User |<------------------------->| Issuer |
SHOULD be a special authentication key used only for this purpose, +------------+ +------------+
but MAY also be an existing K_TOKEN. (In this case, implementations | |
MUST protect against attacks where K_TOKEN is used to pre-compute MAC | |
values.) If no authentication key is present in the cryptographic | |
module, and no K_TOKEN existed before the DSKPP run, K_AUTH MUST be V V
the newly generated K_TOKEN. +--------------+ +--------------+
| DSKPP | Authentication Data | DSKPP |
| Client |----------------------->| Server |
+--------------+ +--------------+
If DSKPP-PRF is used as the MAC algorithm, then the input parameter s Figure 5: User Authentication with One-Time Code
MUST consist of the concatenation of the (ASCII) string "MAC 2
computation", R_C, the parameter dsLen MUST be set to the length of
R_C:
dsLen = len(R_C) The Authentication Code, AUTHCODE, may be considered as a special
form of a shared secret between a User and a DSKPP server. The
Issuer may generate the Authentication Code as follows:
MAC = DSKPP-PRF (K_AUTH, "MAC 2 computation" || R_C, dsLen) AUTHCODE = passwordLen || identifier || password || checksum
4.8.2. Two-pass DSKPP where
4.8.2.1. Key Confirmation passwordLen : 1 digit indicating the 'password' length. The maximum
length of the password is 10. A passwordLen value '0'
indicates a password of 10 digits.
In two-pass DSKPP, the client is REQUIRED to include a nonce R in the identifier : A globally unique identifier of the user's order for
<ClientHello> message. Further, the server is REQUIRED to include an token provisioning. The length of the identifier may be
identifier, ID_S, for itself (via the key container) in the fixed e.g. 10 digits or variable e.g. 1 to 20 digits. The
<ServerFinished> message. The MAC value in the <ServerFinished> identifier may be generated as a sequence number.
message MUST be computed on the (ASCII) string "MAC 1 computation",
the server identifier ID_S, and R using a MAC key K_MAC. Again, in
contrast with the MAC calculation in the four-pass DSKPP, this key
MUST be provided together with K_TOKEN to the cryptographic module,
and hence there is no need for a K_AUTH for key confirmation
purposes.
If DSKPP-PRF is used as the MAC algorithm, then the input parameter s password : 6 to 10 digits. The password should be generated by the
MUST consist of the concatenation of the (ASCII) string "MAC 1 system as a random number to make the AUTHCODE more
computation" and R, and the parameter dsLen MUST be set to the length difficult to guess.
of R:
dsLen = len(R) checksum : 1 digit calculated from the remaining digits in the code.
MAC = DSKPP-PRF (K_MAC, "MAC 1 computation" || ID_S || R, dsLen)
4.8.2.2. Server Authentication The Authentication Data, AUTHDATA, may be derived from the AUTHCODE
and other information as follows:
As discussed in Section 4.3.2, servers need to authenticate MAC = DSKPP-PRF-AES(K_AUTHCODE, AUTHCODE->Identifier || URL_S ||
themselves when attempting to replace an existing K_TOKEN. In 2-pass [R_S], 16)
DSKPP, servers authenticate themselves by including a second MAC
value in the AuthenticationDataType element. The MAC value in the
AuthenticationDataType element MUST be computed on the (ASCII) string
"MAC 1 computation", the server identifier ID_S, and R, using the
existing MAC key K_MAC' (the MAC key that existed before this
protocol run). The MAC algorithm MUST be the same as the algorithm
used for key confirmation purposes.
If DSKPP-PRF is used as the MAC algorithm, then the input parameter s where
MUST consist of the concatenation of the (ASCII) string "MAC 1 Refer to Section 5.1 for a description of DSKPP-PRF in general and
computation" ID_S, and R. The parameter dsLen MUST be set to at least Appendix B for a description of DSKPP-PRF-AES.
16 (i.e. the length of the MAC MUST be at least 16 octets):
dsLen >= 16 In four-pass DSKPP, the cryptographic module uses the client nonce
R_C, the server nonce R_S, and the server URL URL_S to calculate
the MAC. In two-pass DSKPP, the cryptographic module does not
have access to the server nonce R_S therefore only the client
nonce R_C is used in combination with the server URL URL_S to
produce the MAC.
MAC = DSKPP-PRF (K_MAC', "MAC 1 computation" || ID_S || R, dsLen) The K_AUTHCODE MAY be derived from AUTHCODE>password as follows:
K_AUTHCODE = truncate( Hash( Hash(...n times...(
AUTHCODE->password ||R_C||[K]) ) ) )
4.8.3. One-pass DSKPP where
4.8.3.1. Key Confirmation K is optional and MAY be one of the following:
In one-pass DSKPP, the server MUST include an identifier, ID_S, for K_CLIENT: The device public key when a device
itself (via the key container) in the <ServerFinished> message. The certificate is available and used for key transport
MAC value in the <ServerFinished> message MUST be computed on the in 2-pass
(ASCII) string "MAC 1 computation", the server identifier ID_S, and
an unsigned integer value I, using a MAC key K_MAC. The value I MUST
be monotonically increasing and guaranteed not to be used again by
this server towards this cryptographic module. It could for example
be the number of seconds since some point in time with sufficient
granularity, a counter value, or a combination of the two where the
counter value is reset for each new time value. In contrast to the
MAC calculation in four-pass DSKPP, the MAC key K_MAC MUST be
provided together with K_TOKEN to the cryptographic module, and hence
there is no need for a K_AUTH for key confirmation purposes.
Note: The integer I does not necessarily need to be maintained per K_SHARED: The shared key between the Client and the
cryptographic module by the DSKPP server (it is enough if the server Server when it is used for key wrap in two-pass or
can guarantee that the same value is never being sent twice to the for R_C protection in four-pass
same cryptographic module).
If DSKPP-PRF is used as the MAC algorithm, then the input parameter s K_DERIVED: when a passphrase derived key is used for
MUST consist of the concatenation of the (ASCII) string "MAC 1 key wrap in two-pass.
computation", ID_S, and I. The parameter dsLen MUST be set to at
least 16 (i.e. the length of the MAC MUST be at least 16 octets):
dsLen >= 16 'truncate()' returns the first 16 bytes from the result of the
last hash iteration, and n is the number of hash iterations. n
may be any number between 10 and 1000.
MAC = DSKPP-PRF (K_MAC, "MAC 1 computation" || ID_S || I, dsLen) Notes:
1 Authentication data MAY be omitted if client certificate
authentication has been provided by the transport channel such as
TLS.
The server MUST provide I to the client in the Nonce attribute of the 2 When an issuer delegates symmetric key provisioning to a third
<Mac> element of the <ServerFinished> message using the party provisioning service provider, both client authentication
AuthenticationCodeMacType defined in Section 4.9.12. and issuer authentication are required by the provisioning server.
Client authentication to the issuer MAY be in-band or out-of-band
as described above. The issuer acts as a proxy for the
provisioning server. The issuer authenticates to the provisioning
service provider either using a certificate or a pre-established
secret key.
4.8.3.2. Server Authentication 5.4. Client Authentication Examples
As discussed in Section 4.3.2, servers need to authenticate 5.4.1. Example Using a MAC from an Authentication Code
themselves when attempting to replace an existing K_TOKEN. In 1-pass
DSKPP, servers authenticate themselves by including a second MAC
value in the AuthenticationDataType element. The MAC value in the
AuthenticationDataType element MUST be computed on the (ASCII) string
"MAC 1 computation", the server identifier ID_S, and a new value I',
I' > I, using the existing MAC key K_MAC' (the MAC key that existed
before this protocol run). The MAC algorithm MUST be the same as the
algorithm used for key confirmation purposes.
If DSKPP-PRF is used as the MAC algorithm, then the input parameter s <AuthenticationData>
MUST consist of the concatenation of the (ASCII) string "MAC 1 <ClientID>31300257</ClientID>
computation" ID_S, and I'. The parameter dsLen MUST be set to at <AuthenticationCodeMac>
least 16 (i.e. the length of the MAC MUST be at least 16 octets): <IterationCount>512</IterationCount>
<Mac>4bRJf9xXd3KchKoTenHJiw==</Mac>
</AuthenticationCodeMac>
</AuthenticationData>
dsLen >= 16 5.4.2. Example Using a Device Certificate
MAC = DSKPP-PRF (K_MAC', "MAC 1 computation" || ID_S || I', dsLen) <AuthenticationData>
<DigitalSignature>
<ds:SignedInfo>
<ds:CanonicalizationMethod
Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" />
<ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
<ds:Reference URI="#Nonce">
<ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
<ds:DigestValue></ds:DigestValue>
</ds:Reference>
</ds:SignedInfo>
<ds:SignatureValue></ds:SignatureValue>
<ds:KeyInfo>
<ds:X509Data>
<ds:X509Certificate>miib</ds:X509Certificate>
</ds:X509Data>
</ds:KeyInfo>
<ds:Object Id="Nonce">xwQzwEl0CjPAiQeDxwRJdQ==</ds:Object>
</DigitalSignature>
The server MUST provide I' to the client in the Nonce attribute of 6. Four-Pass Protocol
the <Mac> element of the AuthenticationDataType extension. If the
protocol run is successful, the client stores I' as the new value of
I for this server.
4.9. DSKPP Schema Basics In this section, example messages are used to describe parameters,
encoding and semantics in a 4-pass DSKPP exchanges. The examples are
written using XML. While they are syntactically correct, MAC and
cipher values are fictitious.
This section describes the schema used by DSKPP. The DSKPP XML 6.1. XML Basics
schema itself can be found in Section 6. Specific protocol message
elements are defined in Section 4.10. Examples can be found in
Appendix B.
Some DSKPP elements rely on the parties being able to compare The DSKPP XML schema can be found in Section 13. Some DSKPP elements
received values with stored values. Unless otherwise noted, all rely on the parties being able to compare received values with stored
elements in this document that have the XML Schema "xs:string" type, values. Unless otherwise noted, all elements in this document that
or a type derived from it, MUST be compared using an exact binary have the XML Schema "xs:string" type, or a type derived from it, MUST
comparison. In particular, DSKPP implementations MUST NOT depend on be compared using an exact binary comparison. In particular, DSKPP
case-insensitive string comparisons, normalization or trimming of implementations MUST NOT depend on case-insensitive string
white space, or conversion of locale-specific formats such as comparisons, normalization or trimming of white space, or conversion
numbers. of locale-specific formats such as numbers.
Implementations that compare values that are represented using Implementations that compare values that are represented using
different character encodings MUST use a comparison method that different character encodings MUST use a comparison method that
returns the same result as converting both values to the Unicode returns the same result as converting both values to the Unicode
character encoding, Normalization Form C [UNICODE], and then character encoding, Normalization Form C [UNICODE], and then
performing an exact binary comparison. performing an exact binary comparison.
No collation or sorting order for attributes or element values is No collation or sorting order for attributes or element values is
defined. Therefore, DSKPP implementations MUST NOT depend on defined. Therefore, DSKPP implementations MUST NOT depend on
specific sorting orders for values. specific sorting orders for values.
4.9.1. The AbstractRequestType Type 6.2. Round-Trip #1: <KeyProvClientHello> and <KeyProvServerHello>
All DSKPP requests are defined as extensions to the abstract
AbstractRequestType type. The elements of the AbstractRequestType,
therefore, apply to all DSKPP requests. All DSKPP requests MUST
contain a Version attribute. For this version of this specification,
Version MUST be set to "1.0".
<xs:complexType name="AbstractRequestType" abstract="true">
<xs:attribute name="Version" type="VersionType" use="required"/>
</xs:complexType>
4.9.2. The AbstractResponseType Type
All DSKPP responses are defined as extensions to the abstract
AbstractResponseType type. The elements of the AbstractResponseType,
therefore, apply to all DSKPP responses. All DSKPP responses contain
a Version attribute indicating the version that was used. A Status
attribute, which indicates whether the preceding request was
successful or not MUST also be present. Finally, all responses MAY
contain a SessionID attribute identifying the particular DSKPP
session. The SessionID attribute needs only be present if more than
one roundtrip is REQUIRED for a successful protocol run (this is the
case with the protocol version described herein).
<xs:complexType name="AbstractResponseType" abstract="true">
<xs:attribute name="Version" type="VersionType" use="required"/>
<xs:attribute name="SessionID" type="IdentifierType"/>
<xs:attribute name="Status" type="StatusCode" use="required"/>
</xs:complexType>
4.9.3. The VersionType Type
The VersionType type is used within DSKPP messages to identify the
highest version of this protocol supported by the DSKPP client and
server.
<xs:simpleType name="VersionType">
<xs:restriction base="xs:string">
<xs:pattern value="\d{1,2}\.\d{1,3}"/>
</xs:restriction>
</xs:simpleType>
4.9.4. The IdentifierType Type 6.2.1. Examples
The IdentifierType type is used to identify various DSKPP elements, 6.2.1.1. Example Without a Preceding Trigger
such as sessions, users, and services. Identifiers MUST NOT be
longer than 128 octets.
<xs:simpleType name="IdentifierType"> <?xml version="1.0" encoding="UTF-8"?>
<xs:restriction base="xs:string"> <dskpp:KeyProvClientHello Version="1.0"
<xs:maxLength value="128"/> xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
</xs:restriction> xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
</xs:simpleType> xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<DeviceIdentifierData>
<DeviceId>
<pskc:Manufacturer>ManufacturerABC</pskc:Manufacturer>
<pskc:SerialNo>XL0000000001234</pskc:SerialNo>
<pskc:Model>U2</pskc:Model>
</DeviceId>
</DeviceIdentifierData>
<SupportedKeyTypes>
<Algorithm>urn:ietf:params:xml:schema:keyprov:otpalg#HOTP</Algorithm>
<Algorithm>
http://www.rsa.com/rsalabs/otps/schemas/2005/09/otps-wst#SecurID-AES
</Algorithm>
</SupportedKeyTypes>
<SupportedEncryptionAlgorithms>
<Algorithm>http://www.w3.org/2001/05/xmlenc#rsa_1_5</Algorithm>
<Algorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</Algorithm>
</SupportedEncryptionAlgorithms>
<SupportedMacAlgorithms>
<Algorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</Algorithm>
</SupportedMacAlgorithms>
<SupportedProtocolVariants><FourPass/></SupportedProtocolVariants>
<SupportedKeyContainers>
<KeyContainerFormat>
urn:ietf:params:xml:schema:keyprov:container#KeyContainer
</KeyContainerFormat>
</SupportedKeyContainers>
</dskpp:KeyProvClientHello>
4.9.5. The StatusCode Type <?xml version="1.0" encoding="UTF-8"?>
<dskpp:KeyProvServerHello Version="1.0" SessionID="4114" Status="Success"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<KeyType>
urn:ietf:params:xml:schema:keyprov:otpalg#SecurID-AES
</KeyType>
<EncryptionAlgorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</EncryptionAlgorithm>
<MacAlgorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</MacAlgorithm>
<EncryptionKey>
<ds:KeyName>KEY-1</ds:KeyName>
</EncryptionKey>
<KeyContainerFormat>
urn:ietf:params:xml:schema:keyprov:container#KeyContainer
</KeyContainerFormat>
<Payload>
<Nonce>qw2ewasde312asder394jw==</Nonce>
</Payload>
</dskpp:KeyProvServerHello>
The StatusCode type enumerates all possible return codes: 6.2.1.2. Example Assuming a Preceding Trigger
<xs:simpleType name="StatusCode"> <?xml version="1.0" encoding="UTF-8"?>
<xs:restriction base="xs:string">
<xs:enumeration value="Continue"/>
<xs:enumeration value="Success"/>
<xs:enumeration value="Abort"/>
<xs:enumeration value="AccessDenied"/>
<xs:enumeration value="MalformedRequest"/>
<xs:enumeration value="UnknownRequest"/>
<xs:enumeration value="UnknownCriticalExtension"/>
<xs:enumeration value="UnsupportedVersion"/>
<xs:enumeration value="NoSupportedKeyTypes"/>
<xs:enumeration value="NoSupportedEncryptionAlgorithms"/>
<xs:enumeration value="NoSupportedMACAlgorithms"/>
<xs:enumeration value="NoProtocolVariants"/>
<xs:enumeration value="NoSupportedKeyContainers"/>
<xs:enumeration value="AuthenticationDataInvalid"/>
<xs:enumeration value="InitializationFailed"/>
</xs:restriction>
</xs:simpleType>
Upon transmission or receipt of a message for which the Status <dskpp:KeyProvClientHello Version="1.0"
attribute's value is not "Success" or "Continue", the default xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
behavior, unless explicitly stated otherwise below, is that both the xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
DSKPP server and the DSKPP client MUST immediately terminate the xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
DSKPP session. DSKPP servers and DSKPP clients MUST delete any xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
secret values generated as a result of failed runs of the DSKPP xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
protocol. Session identifiers MAY be retained from successful or keyprov-dskpp-1.0.xsd">
failed protocol runs for replay detection purposes, but such retained <DeviceIdentifierData>
identifiers MUST not be reused for subsequent runs of the protocol. <DeviceId>
<pskc:Manufacturer>ManufacturerABC</pskc:Manufacturer>
<pskc:SerialNo>XL0000000001234</pskc:SerialNo>
<pskc:Model>U2</pskc:Model>
</DeviceId>
</DeviceIdentifierData>
<KeyID>SE9UUDAwMDAwMDAx</KeyID>
<TriggerNonce>112dsdfwf312asder394jw==</TriggerNonce>
<SupportedKeyTypes>
<Algorithm>urn:ietf:params:xml:schema:keyprov:otpalg#HOTP</Algorithm>
<Algorithm>
http://www.rsa.com/rsalabs/otps/schemas/2005/09/otps-wst#SecurID-AES
</Algorithm>
</SupportedKeyTypes>
<SupportedEncryptionAlgorithms>
<Algorithm>http://www.w3.org/2001/05/xmlenc#rsa_1_5</Algorithm>
<Algorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</Algorithm>
</SupportedEncryptionAlgorithms>
<SupportedMacAlgorithms>
<Algorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</Algorithm>
</SupportedMacAlgorithms>
<SupportedProtocolVariants><FourPass/></SupportedProtocolVariants>
<SupportedKeyContainers>
<KeyContainerFormat>
urn:ietf:params:xml:schema:keyprov:container#KeyContainer
</KeyContainerFormat>
</SupportedKeyContainers>
</dskpp:KeyProvClientHello>
When possible, the DSKPP client SHOULD present an appropriate error <?xml version="1.0" encoding="UTF-8"?>
message to the user. <dskpp:KeyProvServerHello Version="1.0" SessionID="4114" Status="Success"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<KeyType>
http://www.rsa.com/rsalabs/otps/schemas/2005/09/otps-wst#SecurID-AES
</KeyType>
<EncryptionAlgorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</EncryptionAlgorithm>
<MacAlgorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</MacAlgorithm>
<EncryptionKey>
<ds:KeyName>KEY-1</ds:KeyName>
</EncryptionKey>
<KeyContainerFormat>
urn:ietf:params:xml:schema:keyprov:container#KeyContainer
</KeyContainerFormat>
<Payload>
<Nonce>qw2ewasde312asder394jw==</Nonce>
</Payload>
<Mac MacAlgorithm=
"urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes">
cXcycmFuZG9tMzEyYXNkZXIzOTRqdw==
</Mac>
</dskpp:KeyProvServerHello>
These status codes are valid in all DSKPP Response messages unless 6.2.2. Components of the <KeyProvClientHello> Request
explicitly stated otherwise:
o "Continue" indicates that the DSKPP server is ready for a
subsequent request from the DSKPP client. It cannot be sent in
the server's final message.
o "Success" indicates successful completion of the DSKPP session.
It can only be sent in the server's final message.
o "Abort" indicates that the DSKPP server rejected the DSKPP
client's request for unspecified reasons.
o "AccessDenied" indicates that the DSKPP client is not authorized
to contact this DSKPP server.
o "MalformedRequest" indicates that the DSKPP server failed to parse
the DSKPP client's request.
o "UnknownRequest" indicates that the DSKPP client made a request The components of this message have the following meaning:
that is unknown to the DSKPP server. o Version: (attribute inherited from the AbstractRequestType type)
o "UnknownCriticalExtension" indicates that a critical DSKPP The highest version of this protocol the client supports. Only
extension (see below) used by the DSKPP client was not supported version one ("1.0") is currently specified.
or recognized by the DSKPP server. o <DeviceIdentifierData>: An identifier for the cryptographic module
o "UnsupportedVersion" indicates that the DSKPP client used a DSKPP as defined in Section 5.3 above. The identifier MUST only be
protocol version not supported by the DSKPP server. This error is present if such shared secrets exist or if the identifier was
only valid in the DSKPP server's first response message. provided by the server in a <KeyProvTrigger> element (see
o "NoSupportedKeyTypes" indicates that the DSKPP client only Section 12.2.7 below). In the latter case, it MUST have the same
suggested key types that are not supported by the DSKPP server. value as the identifier provided in that element.
This error is only valid in the DSKPP server's first response o <KeyID>: An identifier for the key that will be overwritten if the
message. protocol run is successful. The identifier MUST only be present
o "NoSupportedEncryptionAlgorithms" indicates that the DSKPP client if the key exists or if the identifier was provided by the server
only suggested encryption algorithms that are not supported by the in a <KeyProvTrigger> element, in which case, it MUST have the
DSKPP server. This error is only valid in the DSKPP server's same value as the identifier provided in that element (see a
first response message. Note that the error will only occur if (Section 9) and Section 12.2.7 below).
the DSKPP server does not support any of the DSKPP client's o <KeyProvClientNonce>: This is the nonce R, which, when present,
suggested encryption algorithms. MUST be used by the server when calculating MAC values (see
o "NoSupportedMACAlgorithms" indicates that the DSKPP client only below). It is RECOMMENDED that clients include this element
suggested MAC algorithms that are not supported by the DSKPP whenever the <KeyID> element is present.
server. This error is only valid in the DSKPP server's first o <TriggerNonce>: This OPTIONAL element MUST be present if and only
response message. Note that the error will only occur if the if the DSKPP run was initialized with a <KeyProvTrigger> message
DSKPP server does not support any of the DSKPP client's suggested (see Section 12.2.7 below), and MUST, in that case, have the same
MAC algorithms. value as the <TriggerNonce> child of that message. A server using
o "NoProtocolVariants" indicates that the DSKPP client only nonces in this way MUST verify that the nonce is valid and that
suggested a protocol variant (either 2-pass or 4-pass) that is not any device or key identifier values provided in the
supported by the DSKPP server. This error is only valid in the <KeyProvTrigger> message match the corresponding identifier values
DSKPP server's first response message. Note that the error will in the <KeyProvClientHello> message.
only occur if the DSKPP server does not support any of the DSKPP o <SupportedKeyTypes>: A sequence of URIs indicating the key types
client's suggested protocol variants. for which the cryptographic module is willing to generate keys
o "NoSupportedKeyContainers" indicates that the DSKPP client only through DSKPP.
suggested key container formats that are not supported by the o <SupportedEncryptionAlgorithms>: A sequence of URIs indicating the
DSKPP server. This error is only valid in the DSKPP server's encryption algorithms supported by the cryptographic module for
first response message. Note that the error will only occur if the purposes of DSKPP. The DSKPP client MAY indicate the same
the DSKPP server does not support any of the DSKPP client's algorithm both as a supported key type and as an encryption
suggested key container formats. algorithm.
o "AuthenticationDataInvalid" indicates that the DSKPP client o <SupportedMacAlgorithms>: A sequence of URIs indicating the MAC
supplied user or device authentication data that the DSKPP server algorithms supported by the cryptographic module for the purposes
failed to validate. of DSKPP. The DSKPP client MAY indicate the same algorithm both
o "InitializationFailed" indicates that the DSKPP server could not as an encryption algorithm and as a MAC algorithm (e.g.,
generate a valid key given the provided data. When this status urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes defined
code is received, the DSKPP client SHOULD try to restart DSKPP, as in Appendix B).
it is possible that a new run will succeed. o <SupportedProtocolVariants>: This OPTIONAL element is used by the
DSKPP client to indicate support for four-pass or two-pass DSKPP.
If two-pass support is specified, then <KeyProvClientNonce> MUST
be set to nonce R in the <KeyProvClientHello> message unless
<TriggerNonce> is already present.
o <SupportedKeyContainers>: This OPTIONAL element is a sequence of
URIs indicating the key container formats supported by the DSKPP
client. If this element is not provided, then the DSKPP server
MUST proceed with
"urn:ietf:params:xml:schema:keyprov:container#KeyContainer" (see
[PSKC]).
o <AuthenticationData>: This OPTIONAL element contains data that the
DSKPP client uses to authenticate the user or device to the DSKPP
server. The element is set as specified in Section 5.3.
o <Extensions>: A sequence of extensions. One extension is defined
for this message in this version of DSKPP: the ClientInfoType (see
Section 10).
4.9.6. The DeviceIdentifierDataType Type 6.2.2.1. The DSKPP Client: The DeviceIdentifierDataType Type
The DeviceIdentifierDataType type is used to uniquely identify the The DeviceIdentifierDataType type is used to uniquely identify the
device that houses the cryptographic module, e.g., a mobile phone. device that houses the cryptographic module, e.g., a mobile phone.
The device identifier allows the DSKPP server to find, e.g., a pre- The device identifier allows the DSKPP server to find, e.g., a pre-
shared transport key for 2-pass DSKPP and/or the correct shared shared transport key for 2-pass DSKPP and/or the correct shared
secret for MAC'ing purposes. The default DeviceIdentifierDataType is secret for MAC'ing purposes. The default DeviceIdentifierDataType is
defined in [PSKC]. defined in [PSKC].
<xs:complexType name="DeviceIdentifierDataType"> 6.2.2.2. Selecting a Protocol Variant: The ProtocolVariantsType Type
<xs:choice>
<xs:element name="DeviceID" type="pskc:DeviceIdType"/>
<xs:any namespace="##other" processContents="strict"/>
</xs:choice>
</xs:complexType>
4.9.7. The TokenPlatformInfoType and PlatformType Types
The TokenPlatformInfoType type is used to carry characteristics of
the intended cryptographic module platform, and applies in the
public-key variant of DSKPP in situations when the client potentially
needs to select a cryptographic module to initialize.
<xs:simpleType name="PlatformType">
<xs:restriction base="xs:string">
<xs:enumeration value="Hardware"/>
<xs:enumeration value="Software"/>
<xs:enumeration value="Unspecified"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="TokenPlatformInfoType">
<xs:attribute name="KeyLocation" type="dskpp:PlatformType"/>
<xs:attribute name="AlgorithmLocation" type="dskpp:PlatformType"/>
</xs:complexType>
4.9.8. The NonceType Type
The NonceType type is used to carry pseudorandom values in DSKPP
messages. A nonce, as the name implies, MUST be used only once. For
each DSKPP message that requires a nonce element to be sent, a fresh
nonce MUST be generated each time. Nonce values MUST be at least 16
octets long.
<xs:simpleType name="NonceType">
<xs:restriction base="xs:base64Binary">
<xs:minLength value="16"/>
</xs:restriction>
</xs:simpleType>
4.9.9. The AlgorithmsType Type
The AlgorithmsType type is a list of type-value pairs that define
algorithms supported by a DSKPP client or server. Algorithms are
identified through URIs.
<xs:complexType name="AlgorithmsType">
<xs:sequence maxOccurs="unbounded">
<xs:element name="Algorithm" type="AlgorithmType"/>
</xs:sequence>
</xs:complexType>
<xs:simpleType name="AlgorithmType">
<xs:restriction base="xs:anyURI"/>
</xs:simpleType>
4.9.10. The ProtocolVariantsType and the TwoPassSupportType Types
The ProtocolVariantsType type is OPTIONALLY used by the DSKPP client
to indicate the number of passes of the DSKPP protocol that it
supports (see Section 4.2). The ProtocolVariantsType MAY be used to
indicate support for 4-pass or 2-pass DSKPP. Because 1-pass DSKPP
does not include a client request to the server, the
ProtocolVariantsType type MAY NOT be used to indicate support for
1-pass DSKPP. If the ProtocolVariantsType is not used, then the
DSKPP server will proceed with ordinary 4-pass DSKPP. However, it
does not support 4-pass DSKPP, then the server MUST find a suitable
two-pass variant or else the protocol run will fail.
<xs:complexType name="ProtocolVariantsType">
<xs:sequence>
<xs:element name="FourPass" minOccurs="0"/>
<xs:element name="TwoPass" type="dskpp:TwoPassSupportType"
minOccurs="0"/>
<xs:element name="OnePass" minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="TwoPassSupportType"> The ProtocolVariantsType type is OPTIONAL for a DSKPP client, who MAY
<xs:sequence maxOccurs="unbounded"> use it to indicate the number of passes of the DSKPP protocol that it
<xs:element name="SupportedKeyInitializationMethod" supports. The ProtocolVariantsType MAY be used to indicate support
type="xs:anyURI"/> for 4-pass or 2-pass DSKPP. Because 1-pass DSKPP does not include a
<xs:element name="Payload" minOccurs="0"/> client request to the server, the ProtocolVariantsType type MAY NOT
</xs:sequence> be used to indicate support for 1-pass DSKPP. If the
</xs:complexType> ProtocolVariantsType is not used, then the DSKPP server will proceed
with ordinary 4-pass DSKPP. However, it does not support 4-pass
DSKPP, then the server MUST find a suitable two-pass variant or else
the protocol run will fail.
The TwoPassSupportType type signals client support for the 2-pass The TwoPassSupportType type signals client support for the 2-pass
version of DSKPP, informs the server of supported two-pass variants, version of DSKPP, informs the server of supported two-pass variants,
and provides OPTIONAL payload data to the DSKPP server. The payload and provides OPTIONAL payload data to the DSKPP server. The payload
is sent in an opportunistic fashion, and MAY be discarded by the is sent in an opportunistic fashion, and MAY be discarded by the
DSKPP server if the server does not support the two-pass variant the DSKPP server if the server does not support the two-pass variant the
payload is associated with. The elements of this type have the payload is associated with. The elements of this type have the
following meaning: following meaning:
o <SupportedKeyInitializationMethod>: A two-pass key initialization o <SupportedKeyInitializationMethod>: A two-pass key initialization
method supported by the DSKPP client. Multiple supported methods method supported by the DSKPP client. Multiple supported methods
MAY be present, in which case they MUST be listed in order of MAY be present, in which case they MUST be listed in order of
precedence. precedence.
o <Payload>: An OPTIONAL payload associated with each supported key o <Payload>: An OPTIONAL payload associated with each supported key
initialization method. initialization method.
A DSKPP client that indicates support for two-pass DSKPP MUST also A DSKPP client that indicates support for two-pass DSKPP MUST also
include the nonce R in its <ClientHello> message (this will enable include the nonce R in its <KeyProvClientHello> message (this will
the client to verify that the DSKPP server it is communicating with enable the client to verify that the DSKPP server it is communicating
is alive). with is alive).
4.9.11. The KeyContainersFormatTypeType
The KeyContainersFormatType type is a list of type-value pairs that
are OPTIONALLY used to define key container formats supported by a
DSKPP client or server. Key container formats are identified through
URIs, e.g., the PSKC URI
"http://www.openauthentication.org/OATH/2006/10/PSKC#KeyContainer"
(see [PSKC].
<xs:complexType name="KeyContainersFormatType"> 6.2.2.3. Selecting a Key Container Format: The KeyContainersFormatType
<xs:sequence maxOccurs="unbounded"> Type
<xs:element name="KeyContainerFormat"
type="dskpp:KeyContainerFormatType"/>
</xs:sequence>
</xs:complexType>
<xs:simpleType name="KeyContainerFormatType"> The OPTIONAL KeyContainersFormatType type is a list of type-value
<xs:restriction base="xs:anyURI"/> pairs that a DSKPP client or server MAY use to define key container
</xs:simpleType> formats it supports. Key container formats are identified through
URIs, e.g., the PSKC KeyContainer URI
"urn:ietf:params:xml:schema:keyprov:container#KeyContainer" (see
[PSKC]).
4.9.12. The AuthenticationDataType Type 6.2.2.4. Selecting a Client and Server Authentication Mechanism: The
AuthenticationDataType Type
The AuthenticationDataType type is OPTIONALLY used to carry client or The OPTIONAL AuthenticationDataType type is used by DSKPP clients and
server authentication values in DSKPP messages (see Section 4.3). server to carry authentication values in DSKPP messages. The element
The element MAY be used as follows: MAY contain a device certificate or MAC derived from an
authentication code as follows:
a. A DSKPP client MAY include a one-time use AuthenticationCode that a. A DSKPP client MAY include a one-time use AuthenticationCode that
was given by the issuer to the user for acquiring a symmetric was given by the issuer to the user for acquiring a symmetric
key. An AuthenticationCode MAY or MAY NOT contain alphanumeric key. An AuthenticationCode MAY or MAY NOT contain alphanumeric
characters in addition to numeric digits depending on the device characters in addition to numeric digits depending on the device
type and policy of the issuer. For example, if the device is a type and policy of the issuer. For example, if the device is a
mobile phone, a code that the user enters on the keypad would mobile phone, a code that the user enters on the keypad would
typically be restricted to numeric digits for ease of use. An typically be restricted to numeric digits for ease of use. An
activation code can be sent to the DSKPP server in plaintext authentication code MAY be sent to the DSKPP server as MAC data
form, hashed data form, or keyed hash data form depending on the calculated according to section Section 5.3.3.
underlying transport protocol. b. A DSKPP client MAY contain Authentication Data consisting of
b. A DSKPP client MAY include an AuthenticationCertificate that signed data of client Nonce with a client certificate's private
contains a certificate issued with the device by the issuer. key. A service provider may have a policy to issue symmetric
keys for a device only if it has a trusted device certificate.
An authentication code isn't required in this case.
c. A DSKPP server MAY use the AuthenticationDataType element c. A DSKPP server MAY use the AuthenticationDataType element
AuthenticationCodeMac to carry a MAC for authenticating itself to AuthenticationCodeMac to carry a MAC for authenticating itself to
the client. For example, when a successful 1- or 2-pass DSKPP the client. For example, when a successful 1- or 2-pass DSKPP
protocol run will result in an existing key being replaced, then protocol run will result in an existing key being replaced, then
the DSKPP server MUST include a MAC proving to the DSKPP client the DSKPP server MUST include a MAC proving to the DSKPP client
that the server knows the value of the key it is about to that the server knows the value of the key it is about to
replace. replace.
<xs:complextype name="AuthenticationDataType">
<xs:sequence>
<xs:element name="ClientID" type="dskpp:IdentifierType"
minOccurs="0"/>
<xs:choice minOccurs="0">
<xs:element name="AuthenticationCode"
type="dskpp:AuthenticationCodeType"/>
<xs:element name="AuthenticationCodeDigest"
type="dskpp:AuthenticationCodeDigestType"/>
<xs:element name="AuthenticationCodeMac"
type="dskpp:AuthenticationCodeMacType"/>
<xs:element name="AuthenticationCertificate"
type="ds:KeyInfoType"/>
</xs:choice>
</xs:sequence>
</xs:complexType>
<xs:simpleType name="AuthenticationCodeType">
<xs:restriction base="xs:string">
<xs:maxLength value="20"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="AuthenticationCodeDigestType">
<xs:simpleContent>
<xs:extension base="xs:base64Binary">
<xs:attribute name="HashAlgorithm" type="xs:anyURI"
use="required"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:complexType name="AuthenticationCodeMacType">
<xs:sequence>
<xs:element name="Data" type="xs:base64Binary">
<xs:element name="Nonce" type="dskpp:NonceType"/>
</xs:sequence>
<attribute name="HMACAlgorithm" type="xs:anyURI"
use="required"/>
<attribute name="NonceId" type="dskpp:IdentifierType"/>
</xs:complexType>
The element of the AuthenticationDataType type have the following The element of the AuthenticationDataType type have the following
meaning: meaning:
o <ClientID>: A requestor's identifier. The value MAY be a user ID, o <ClientID>: A requester's identifier. The value MAY be a user ID,
a device ID, or a keyID associated with the requestor's a device ID, or a keyID associated with the requester's
authentication value. When the authentication data is based on a authentication value. When the authentication data is based on a
certificate, <ClientID> can be omitted, as the certificate itself certificate, <ClientID> can be omitted, as the certificate itself
is typically sufficient to identify the requestor. Also, if a is typically sufficient to identify the requester. Also, if a
<DSKPPTrigger> message was provided by the server to initiate the <KeyProvTrigger> message was provided by the server to initiate
DSKPP protocol run, <ClientID> can be omitted, as the DeviceID, the DSKPP protocol run, <ClientID> can be omitted, as the
KeyID, and/or nonce provided in the <InitializationTriggerType> DeviceID, KeyID, and/or nonce provided in the
element ought to be sufficient to identify the requestor. <InitializationTriggerType> element ought to be sufficient to
o <AuthenticationCode>: A one-time use value sent in the clear to identify the requester.
the DSKPP server.
o <AuthenticationCodeDigest>: A one-time use value sent in digest
form to the DSKPP server.
o <AuthenticationCodeMac>: An authentication MAC and OPTIONAL o <AuthenticationCodeMac>: An authentication MAC and OPTIONAL
additional information (e.g., MAC algorithm). The value could be additional information (e.g., MAC algorithm). The value could be
a one-time use value sent as a MAC value to the DSKPP server; or, a one-time use value sent as a MAC value to the DSKPP server; or,
it could be a MAC value sent to the DSKPP client, where the MAC is it could be a MAC value sent to the DSKPP client. Refer to
calculated as described in Section 4.8. section Section 5.3.3 for calculation of MAC with an
o <AuthenticationCertificate>: A device certificate sent to the authentication code.
DSKPP server. o <DigitalSignature>: Client nonce R_C signed using the device
certificate and sent in KeyProvClientHello for two-pass protocol
or in KeyProvClientNonce for four-pass protocol.
4.9.13. The PayloadType Type 6.2.3. Components of the <KeyProvServerHello> Response
The PayloadType type is used to carry data in a DSKPP client or This message is the first message sent from the DSKPP server to the
server message. For this version of the protocol, only one payload DSKPP client (assuming a trigger message has not been sent to
is defined, the pseudorandom string R_S, for one message, the DSKPP initiate the protocol, in which case, this message is the second
<ServerHello>. message sent from the DSKPP server to the DSKPP client). It is sent
upon reception of a <KeyProvClientHello> message. The components of
this message have the following meaning:
<xs:complexType name="PayloadType"> o Version: (attribute inherited from the AbstractResponseType type)
<xs:choice> The version selected by the DSKPP server. MAY be lower than the
<xs:element name="Nonce" type="dskpp:NonceType"/> version indicated by the DSKPP client, in which case, local policy
<xs:any namespace="##other" processContents="strict"/> at the client MUST determine whether or not to continue the
</xs:choice> session.
</xs:complexType> o SessionID: (attribute inherited from the AbstractResponseType
type) An identifier for this session.
o Status: (attribute inherited from the AbstractResponseType type)
Return code for the <KeyProvClientHello>. If Status is not
"Continue", only the Status and Version attributes will be
present; otherwise, all the other element MUST be present as well.
o <KeyType>: The type of the key to be generated.
o <EncryptionAlgorithm>: The encryption algorithm to use when
protecting R_C.
o <MacAlgorithm>: The MAC algorithm to be used by the DSKPP server.
o <EncryptionKey>: Information about the key to use when encrypting
R_C. It will either be the server's public key (the <ds:KeyValue>
alternative of ds:KeyInfoType) or an identifier for a shared
secret key (the <ds:KeyName> alternative of ds:KeyInfoType).
o <KeyContainerFormat>: The key container format type to be used by
the DSKPP server. The default setting relies on the
KeyContainerType element defined in
"urn:ietf:params:xml:schema:keyprov:container" [PSKC].
o <Payload>: The actual payload. For this version of the protocol,
only one payload is defined: the pseudorandom string R_S.
o <Extensions>: A list of server extensions. Two extensions are
defined for this message in this version of DSKPP: the
ClientInfoType and the ServerInfoType (see Section 10).
o <Mac>: The MAC MUST be present if the DSKPP run will result in the
replacement of an existing symmetric key with a new one (i.e., if
the <KeyID> element was present in the <ClientHello message). In
this case, the DSKPP server MUST prove to the cryptographic module
that it is authorized to replace it.
4.9.14. The MacType Type The DSKPP client MUST verify the MAC if the successful execution
of the protocol will result in the replacement of an existing
symmetric key with a newly generated one. The DSKPP client MUST
terminate the DSKPP session if the MAC does not verify, and MUST
delete any nonces, keys, and/or secrets associated with the failed
run of the DSKPP protocol.
The MacType's MacAlgorithm attribute MUST, when present, identify
the negotiated MAC algorithm.
The MacType type is used by the DSKPP server to carry a MAC value 6.3. Round-Trip #2: <KeyProvClientNonce> and <KeyProvServerFinished>
that the DSKPP server uses to authenticate itself to the client.
<xs:complexType name="MacType"> 6.3.1. Examples
<xs:simpleContent>
<xs:extension base="xs:base64Binary">
<xs:attribute name="MacAlgorithm" type="xs:anyURI"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
4.9.15. The KeyContainerType Type 6.3.1.1. Example Using Default Encryption
The KeyContainerType type is used by the DSKPP server in its final This message contains the nonce chosen by the cryptographic module,
message to carry symmetric key(s) (in the 2- and 1-pass exchanges) R_C, encrypted by the specified encryption key and encryption
and configuration data. The default element defined for the algorithm.
KeyContainerType is contained in the namespace defined in the PSKC
namespace as KeyContainerType (see [PSKC].
<xs:complexType name="KeyContainerType"> <?xml version="1.0" encoding="UTF-8"?>
<xs:choice> <dskpp:KeyProvClientNonce Version="1.0" SessionID="4114"
<xs:element name="KeyContainer" xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
type="pskc:KeyContainerType"/> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
<xs:element name="##other" processContents="strict"/> xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
</xs:choice> keyprov-dskpp-1.0.xsd">
</xs:complexType> <EncryptedNonce>VXENc+Um/9/NvmYKiHDLaErK0gk=</EncryptedNonce>
<AuthenticationData>
<ClientID>31300257</ClientID>
<AuthenticationCodeMac>
<IterationCount>512</IterationCount>
<Mac>4bRJf9xXd3KchKoTenHJiw==</Mac>
</AuthenticationCodeMac>
</AuthenticationData>
</dskpp:KeyProvClientNonce>
4.9.16. The ExtensionsType and the AbstractExtensionType Types <?xml version="1.0" encoding="UTF-8"?>
<dskpp:KeyProvServerFinished Version="1.0" SessionID="4114" Status="Success"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<KeyContainer>
<KeyContainer Version="1.0">
<pskc:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1"/>
<pskc:Device>
<pskc:Key
KeyAlgorithm=
"http://www.rsa.com/rsalabs/otps/schemas/2005/09/otps-wst#SecurID-AES"
KeyId="XL0000000001234">
<pskc:Issuer>CredentialIssuer</pskc:Issuer>
<pskc:Usage otp="true">
<pskc:ResponseFormat format="DECIMAL" length="6"/>
</pskc:Usage>
<pskc:FriendlyName>MyFirstToken</pskc:FriendlyName>
<pskc:Data Name="TIME">
<pskc:Value>AAAAADuaygA=</pskc:Value>
</pskc:Data>
<pskc:Expiry>10/30/2012</pskc:Expiry>
</pskc:Key>
</pskc:Device>
</KeyContainer>
</KeyContainer>
<Mac
MacAlgorithm="urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes">
miidfasde312asder394jw==
</Mac>
</dskpp:KeyProvServerFinished>
The ExtensionsType type is a list of type-value pairs that define 6.3.2. Components of a <KeyProvClientNonce> Request
OPTIONAL DSKPP features supported by a DSKPP client or server.
Extensions MAY be sent with any DSKPP message. Please see the
description of individual DSKPP messages in Section 4.11 of this
document for applicable extensions. All DSKPP extensions are defined
as extensions to the AbstractExtensionType type. The elements of the
AbstractExtensionType, therefore, apply to all DSKPP extensions.
Unless an extension is marked as Critical, a receiving party need not
be able to interpret it. A receiving party is always free to
disregard any (non-critical) extensions.
<xs:complexType name="ExtensionsType"> The components of this message have the following meaning:
<xs:sequence maxOccurs="unbounded">
<xs:element name="Extension" type="AbstractExtensionType"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="AbstractExtensionType" abstract="true"> o Version: (inherited from the AbstractRequestType type) MUST be the
<xs:attribute name="Critical" type="xs:boolean"/> same version as in the <KeyProvServerHello> message.
</xs:complexType> o <SessionID>: MUST have the same value as the SessionID attribute
in the received <KeyProvServerHello> message.
o <EncryptedNonce>: The nonce generated and encrypted by the
cryptographic module. The encryption MUST be made using the
selected encryption algorithm and identified key, and as specified
in Section 5.1.
4.10. DSKPP Messages o <AuthenticationData>: The authentication data value MUST be set as
specified in Section 5.3 and Section 6.2.2.4.
o <Extensions>: A list of extensions. Two extensions are defined
for this message in this version of DSKPP: the ClientInfoType and
the ServerInfoType (see Section 10)
4.10.1. Introduction 6.3.3. Components of a <KeyProvServerFinished> Response
In this section, DSKPP messages, including their parameters, encoding This message is the last message of the DSKPP protocol run. In a
and semantics are defined. 4-pass exchange, the DSKPP server sends this message in response to a
<KeyProvClientNonce> message, whereas in a 2-pass exchange, the DSKPP
server sends this message in response to a <KeyProvClientHello>
message. In a 1-pass exchange, the DSKPP server sends only this
message to the client. The components of this message have the
following meaning:
4.10.2. DSKPP Initialization (OPTIONAL) o Version: (inherited from the AbstractResponseType type) The DSKPP
version used in this session.
o SessionID: (inherited from the AbstractResponseType type) The
previously established identifier for this session.
o Status: (inherited from the AbstractResponseType type) Return code
for the <KeyProvServerFinished> message. If Status is not
"Success", only the Status, SessionID, and Version attributes will
be present (the presence of the SessionID attribute is dependent
on the type of reported error); otherwise, all the other elements
MUST be present as well. In this latter case, the
<KeyProvServerFinished> message can be seen as a "Commit" message,
instructing the cryptographic module to store the generated key
and associate the given key identifier with this key.
o <KeyContainer>: The key container containing symmetric key values
(in the case of a 2- or 1-pass exchange) and configuration data.
The default container format is based on the KeyContainerType type
from PSKC, as defined in [PSKC].
o <Extensions>: A list of extensions chosen by the DSKPP server.
For this message, this version of DSKPP defines one extension, the
ClientInfoType (see Section 10).
o <Mac>: To avoid a false "Commit" message causing the cryptographic
module to end up in an initialized state for which the server does
not know the stored key, <KeyProvServerFinished> messages MUST
always be authenticated with a MAC. The MAC MUST be made using
the already established MAC algorithm.
When receiving a <KeyProvServerFinished> message with
Status="Success" for which the MAC verifies, the DSKPP client MUST
associate the generated key K_TOKEN with the provided key
identifier and store this data permanently. After this operation,
it MUST NOT be possible to overwrite the key unless knowledge of
an authorizing key is proven through a MAC on a later
<KeyProvServerHello> (and <KeyProvServerFinished>) message.
The DSKPP server MAY initialize the DSKPP protocol by sending a The DSKPP client MUST verify the MAC. The DSKPP client MUST
<DSKPPTrigger> message. This message MAY, e.g., be sent in response terminate the DSKPP session if the MAC does not verify, and MUST,
to a user requesting key initialization in a browsing session. in this case, also delete any nonces, keys, and/or secrets
associated with the failed run of the DSKPP protocol.
The MacType's MacAlgorithm attribute MUST, when present, identify
the negotiated MAC algorithm.
<xs:complexType name="InitializationTriggerType"> 6.4. DSKPP Server Results: The StatusCode Type
<xs:sequence>
<xs:element name="DeviceIdentifierData"
type="dskpp:DeviceIdentifierDataType" minOccurs="0"/>
<xs:element name="KeyID" type="xs:base64Binary" minOccurs="0"/>
<xs:element name="TokenPlatformInfo"
type="dskpp:TokenPlatformInfoType" minOccurs="0"/>
<xs:element name="TriggerNonce" type="dskpp:NonceType"/>
<xs:element name="DSKPP_URL" type="xs:anyURI" minOccurs="0"/>
<xs:any namespace="##other" processContents="strict"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:element name="DSKPPTrigger" type="DSKPPTriggerType"/> The StatusCode type enumerates all possible return codes. Upon
transmission or receipt of a message for which the Status attribute's
value is not "Success" or "Continue", the default behavior, unless
explicitly stated otherwise below, is that both the DSKPP server and
the DSKPP client MUST immediately terminate the DSKPP session. DSKPP
servers and DSKPP clients MUST delete any secret values generated as
a result of failed runs of the DSKPP protocol. Session identifiers
MAY be retained from successful or failed protocol runs for replay
detection purposes, but such retained identifiers MUST NOT be reused
for subsequent runs of the protocol.
<xs:complexType name="DSKPPTriggerType"> When possible, the DSKPP client SHOULD present an appropriate error
<xs:annotation> message to the user.
<xs:documentation xml:lang="en">
Message used to trigger the device to initiate a
DSKPP protocol run.
</xs:documentation>
</xs:annotation>
<xs:sequence>
<xs:choice>
<xs:element name="InitializationTrigger"
type="dskpp:InitializationTriggerType"/>
<xs:any namespace="##other" processContents="strict"/>
</xs:choice>
</xs:sequence>
<xs:attribute name="Version" type="dskpp:VersionType"/>
</xs:complexType>
The <DSKPPTrigger> element is intended for the DSKPP client and MAY These status codes are valid in all 4-Pass DSKPP Response messages
inform the DSKPP client about the identifier for the device that unless explicitly stated otherwise:
houses the cryptographic module to be initialized, and, OPTIONALLY, o "Continue" indicates that the DSKPP server is ready for a
of the identifier for the key on that module. The latter would apply subsequent request from the DSKPP client. It cannot be sent in
to key renewal. The trigger always contains a nonce to allow the the server's final message.
DSKPP server to couple the trigger with a later DSKPP <ClientHello> o "Success" indicates successful completion of the DSKPP session.
request. Finally, the trigger MAY contain a URL to use when It can only be sent in the server's final message.
contacting the DSKPP server. The <xs:any> elements are for future o "Abort" indicates that the DSKPP server rejected the DSKPP
extensibility. Any provided <DeviceIdentifierData> or <KeyID> values client's request for unspecified reasons.
MUST be used by the DSKPP client in the subsequent <ClientHello> o "AccessDenied" indicates that the DSKPP client is not authorized
request. The OPTIONAL <TokenPlatformInfo> element informs the DSKPP to contact this DSKPP server.
client about the characteristics of the intended cryptographic module o "MalformedRequest" indicates that the DSKPP server failed to parse
platform, and applies in the public-key variant of DSKPP in the DSKPP client's request.
situations when the client potentially needs to decide which one of o "UnknownRequest" indicates that the DSKPP client made a request
several modules to initialize. that is unknown to the DSKPP server.
o "UnknownCriticalExtension" indicates that a critical DSKPP
extension (see below) used by the DSKPP client was not supported
or recognized by the DSKPP server.
o "UnsupportedVersion" indicates that the DSKPP client used a DSKPP
protocol version not supported by the DSKPP server. This error is
only valid in the DSKPP server's first response message.
o "NoSupportedKeyTypes" indicates that the DSKPP client only
suggested key types that are not supported by the DSKPP server.
This error is only valid in the DSKPP server's first response
message.
The Version attribute MUST be set to "1.0" for this version of DSKPP. o "NoSupportedEncryptionAlgorithms" indicates that the DSKPP client
only suggested encryption algorithms that are not supported by the
DSKPP server. This error is only valid in the DSKPP server's
first response message.
o "NoSupportedMacAlgorithms" indicates that the DSKPP client only
suggested MAC algorithms that are not supported by the DSKPP
server. This error is only valid in the DSKPP server's first
response message.
o "NoProtocolVariants" indicates that the DSKPP client only
suggested a protocol variant (either 2-pass or 4-pass) that is not
supported by the DSKPP server. This error is only valid in the
DSKPP server's first response messagei
o "NoSupportedKeyContainers" indicates that the DSKPP client only
suggested key container formats that are not supported by the
DSKPP server. This error is only valid in the DSKPP server's
first response message.
o "AuthenticationDataMissing" indicates that the DSKPP client didn't
provide authentication data that the DSKPP server required.
o "AuthenticationDataInvalid" indicates that the DSKPP client
supplied user or device authentication data that the DSKPP server
failed to validate.
o "InitializationFailed" indicates that the DSKPP server could not
generate a valid key given the provided data. When this status
code is received, the DSKPP client SHOULD try to restart DSKPP, as
it is possible that a new run will succeed.
o "ProvisioningPeriodExpired" indicates that the provisioning period
set by the DSKPP server has expired. When the status code is
received, the DSKPP client SHOULD report the key initialization
failure reason to the user and the user MUST register with the
DSKPP server to initialize a new key.
4.10.3. The DSKPP Client's Initial PDU (2- and 4-Pass) 7. Two-Pass Protocol
This message is the initial message sent from the DSKPP client to the In this section, example messages are used to describe parameters,
DSKPP server. encoding and semantics in a 2-pass DSKPP exchanges. The examples are
written using XML. While they are syntactically correct, MAC and
cipher values are fictitious.
<xs:element name="ClientHello" type="ClientHelloPDU"/> 7.1. XML Basics
<xs:complexType name="ClientHelloPDU"> The DSKPP XML schema can be found in Section 13. Some DSKPP elements
<xs:annotation> rely on the parties being able to compare received values with stored
<xs:documentation xml:lang="en"> values. Unless otherwise noted, all elements in this document that
Message sent from DSKPP client to DSKPP server to initiate a have the XML Schema "xs:string" type, or a type derived from it, MUST
DSKPP session. be compared using an exact binary comparison. In particular, DSKPP
</xs:documentation> implementations MUST NOT depend on case-insensitive string
</xs:annotation> comparisons, normalization or trimming of white space, or conversion
<xs:complexContent> of locale-specific formats such as numbers.
<xs:extension base="AbstractRequestType">
<xs:sequence> Implementations that compare values that are represented using
<xs:element name="DeviceIdentifierData" different character encodings MUST use a comparison method that
type="dskpp:DeviceIdentifierDataType" minOccurs="0"/> returns the same result as converting both values to the Unicode
<xs:element name="KeyID" type="xs:base64Binary" character encoding, Normalization Form C [UNICODE], and then
minOccurs="0"/> performing an exact binary comparison.
<xs:element name="ClientNonce" type="dskpp:NonceType"
minOccurs="0"/> No collation or sorting order for attributes or element values is
<xs:element name="TriggerNonce" type="dskpp:NonceType" defined. Therefore, DSKPP implementations MUST NOT depend on
minOccurs="0"/> specific sorting orders for values.
<xs:element name="SupportedKeyTypes"
type="dskpp:AlgorithmsType"/> 7.2. Round-Trip #1: <KeyProvClientHello> and <KeyProvServerFinished>
<xs:element name="SupportedEncryptionAlgorithms"
type="dskpp:AlgorithmsType"/> 7.2.1. Examples
<xs:element name="SupportedMACAlgorithms"
type="dskpp:AlgorithmsType"/> 7.2.1.1. Example Using the Key Transport Profile
<xs:element name="SupportedProtocolVariants"
type="dskpp:ProtocolVariantsType" minOccurs="0"/> The client indicates support all the Key Transport, Key Wrap, and
<xs:element name="SupportedKeyContainers" Passphrase-Based Key Wrap profiles (see Section 11):
type="dskpp:KeyContainersFormatType" minOccurs="0"/>
<xs:element name="AuthenticationData" <?xml version="1.0" encoding="UTF-8"?>
type="dskpp:AuthenticationDataType" minOccurs="0"/> <dskpp:KeyProvClientHello Version="1.0"
<xs:element name="Extensions" type="dskpp:ExtensionsType" xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
minOccurs="0"/> xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
</xs:sequence> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
</xs:extension> xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
</xs:complexContent> xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
</xs:complexType> keyprov-dskpp-1.0.xsd">
<DeviceIdentifierData>
<DeviceId>
<pskc:Manufacturer>ManufacturerABC</pskc:Manufacturer>
<pskc:SerialNo>XL0000000001234</pskc:SerialNo>
<pskc:Model>U2</pskc:Model>
</DeviceId>
</DeviceIdentifierData>
<ClientNonce>xwQzwEl0CjPAiQeDxwRJdQ==</ClientNonce>
<SupportedKeyTypes>
<Algorithm>urn:ietf:params:xml:schema:keyprov:otpalg#HOTP</Algorithm>
<Algorithm>
http://www.rsa.com/rsalabs/otps/schemas/2005/09/otps-wst#SecurID-AES
</Algorithm>
</SupportedKeyTypes>
<SupportedEncryptionAlgorithms>
<Algorithm>http://www.w3.org/2001/05/xmlenc#rsa_1_5</Algorithm>
<Algorithm>http://www.w3.org/2001/04/xmlenc#kw-aes128</Algorithm>
<Algorithm>urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes</Algorithm>
</SupportedEncryptionAlgorithms>
<SupportedMacAlgorithms>
<Algorithm>urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes</Algorithm>
</SupportedMacAlgorithms>
<SupportedProtocolVariants>
<TwoPass>
<SupportedKeyInitializationMethod>
urn:ietf:params:xml:schema:keyprov:protocol#wrap
</SupportedKeyInitializationMethod>
<Payload xsi:type="ds:KeyInfoType">
<ds:KeyName>Key_001</ds:KeyName>
</Payload>
<SupportedKeyInitializationMethod>
urn:ietf:params:xml:schema:keyprov:protocol#transport
</SupportedKeyInitializationMethod>
<SupportedKeyInitializationMethod>
urn:ietf:params:xml:schema:keyprov:protocol#passphrase-wrap
</SupportedKeyInitializationMethod>
<Payload xsi:type="ds:KeyInfoType">
<ds:X509Data>
<ds:X509Certificate>miib</ds:X509Certificate>
</ds:X509Data>
</Payload>
</TwoPass>
</SupportedProtocolVariants>
<SupportedKeyContainers>
<KeyContainerFormat>
urn:ietf:params:xml:schema:keyprov:container#KeyContainer
</KeyContainerFormat>
</SupportedKeyContainers>
<AuthenticationData>
<DigitalSignature>
<ds:SignedInfo>
<ds:CanonicalizationMethod
Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" />
<ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
<ds:Reference URI="#Nonce">
<ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
<ds:DigestValue></ds:DigestValue>
</ds:Reference>
</ds:SignedInfo>
<ds:SignatureValue></ds:SignatureValue>
<ds:KeyInfo>
<ds:X509Data>
<ds:X509Certificate>miib</ds:X509Certificate>
</ds:X509Data>
</ds:KeyInfo>
<ds:Object Id="Nonce">xwQzwEl0CjPAiQeDxwRJdQ==</ds:Object>
</DigitalSignature>
</AuthenticationData>
</dskpp:KeyProvClientHello>
In this example, the server responds to the previous request using
the key transport profile.
<?xml version="1.0" encoding="UTF-8"?>
<dskpp:KeyProvServerFinished Version="1.0" SessionID="4114" Status="Success"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:xenc="http://www.w3.org/2001/04/xmlenc#"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<KeyContainer>
<KeyContainer Version="1.0">
<pskc:EncryptionMethod
Algorithm="http://www.w3.org/2001/05/xmlenc#rsa_1_5">
<pskc:KeyInfo>
<ds:X509Data>
<ds:X509Certificate>miib</ds:X509Certificate>
</ds:X509Data>
</pskc:KeyInfo>
</pskc:EncryptionMethod>
<pskc:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1"/>
<Device xmlns="urn:ietf:params:xml:ns:keyprov:1.0:container">
<Key KeyAlgorithm="urn:ietf:params:xml:schema:keyprov:otpalg#HOTP"
KeyId="SDU312345678">
<Issuer>CredentialIssuer</Issuer>
<Usage otp="true">
<ResponseFormat format="DECIMAL" length="6"/>
</Usage>
<FriendlyName>MyFirstToken</FriendlyName>
<Data Name="SECRET">
<Value>
7JHUyp3azOkqJENSsh6b2vxXzwGBYypzJxEr+ikQAa229KV/BgZhGA==
</Value>
<ValueDigest>
i8j+kpbfKQsSlwmJYS99lQ==
</ValueDigest>
</Data>
<Data Name="COUNTER">
<Value>AAAAAAAAAAA=</Value>
</Data>
<Expiry>10/30/2012</Expiry>
</Key>
</Device>
</KeyContainer>
</KeyContainer>
<Mac
MacAlgorithm="urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes">
miidfasde312asder394jw==
</Mac>
<AuthenticationData>
<AuthenticationCodeMac>
<Mac>4bRJf9xXd3KchKoTenHJiw==</Mac>
</AuthenticationCodeMac>
</AuthenticationData>
</dskpp:KeyProvServerFinished>
7.2.1.2. Example Using the Key Wrap Profile
The client sends a request that specifies a shared key to protect the
K_TOKEN, and the server responds using the Key Wrap Profile.
Authentication data in this example is basing on an authentication
code rather than a device certificate.
<?xml version="1.0" encoding="UTF-8"?>
<dskpp:KeyProvClientHello Version="1.0"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:pkcs-5="http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5v2-0#"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<DeviceIdentifierData>
<DeviceId>
<pskc:Manufacturer>ManufacturerABC</pskc:Manufacturer>
<pskc:SerialNo>XL0000000001234</pskc:SerialNo>
<pskc:Model>U2</pskc:Model>
</DeviceId>
</DeviceIdentifierData>
<ClientNonce>xwQzwEl0CjPAiQeDxwRJdQ==</ClientNonce>
<SupportedKeyTypes>
<Algorithm>urn:ietf:params:xml:schema:keyprov:otpalg#HOTP</Algorithm>
<Algorithm>
http://www.rsa.com/rsalabs/otps/schemas/2005/09/otps-wst#SecurID-AES
</Algorithm>
</SupportedKeyTypes>
<SupportedEncryptionAlgorithms>
<Algorithm>http://www.w3.org/2001/05/xmlenc#rsa_1_5</Algorithm>
<Algorithm>http://www.w3.org/2001/04/xmlenc#kw-aes128</Algorithm>
<Algorithm>
http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5#pbes2
</Algorithm>
<Algorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</Algorithm>
</SupportedEncryptionAlgorithms>
<SupportedMacAlgorithms>
<Algorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</Algorithm>
</SupportedMacAlgorithms>
<SupportedProtocolVariants>
<TwoPass>
<SupportedKeyInitializationMethod>
urn:ietf:params:xml:schema:keyprov:protocol#wrap
</SupportedKeyInitializationMethod>
<Payload xsi:type="ds:KeyInfoType">
<ds:KeyName>Key_001</ds:KeyName>
</Payload>
</TwoPass>
</SupportedProtocolVariants>
<SupportedKeyContainers>
<KeyContainerFormat>
urn:ietf:params:xml:schema:keyprov:container#KeyContainer
</KeyContainerFormat>
</SupportedKeyContainers>
<AuthenticationData>
<ClientID>31300257</ClientID>
<AuthenticationCodeMac>
<IterationCount>512</IterationCount>
<Mac>4bRJf9xXd3KchKoTenHJiw==</Mac>
</AuthenticationCodeMac>
</AuthenticationData>
</dskpp:KeyProvClientHello>
In this example, the server responds to the previous request using
the key wrap profile.
<?xml version="1.0" encoding="UTF-8"?>
<dskpp:KeyProvServerFinished Version="1.0" Status="Success"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:xenc="http://www.w3.org/2001/04/xmlenc#"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<KeyContainer>
<ServerID>https://www.somedskppservice.com/</ServerID>
<KeyContainer Version="1.0">
<EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#kw-aes128"
xmlns="urn:ietf:params:xml:ns:keyprov:1.0:container">
<KeyInfo>
<ds:KeyName>Key-001</ds:KeyName>
</KeyInfo>
</EncryptionMethod>
<pskc:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1"/>
<Device xmlns="urn:ietf:params:xml:ns:keyprov:1.0:container">
<Key KeyAlgorithm="urn:ietf:params:xml:schema:keyprov:otpalg#HOTP"
KeyId="SDU312345678">
<Issuer>CredentialIssuer</Issuer>
<Usage otp="true">
<ResponseFormat format="DECIMAL" length="6"/>
</Usage>
<FriendlyName>MyFirstToken</FriendlyName>
<Data Name="SECRET">
<Value>
JSPUyp3azOkqJENSsh6b2hdXz1WBYypzJxEr+ikQAa22M6V/BgZhRg==
</Value>
<ValueDigest>
i8j+kpbfKQsSlwmJYS99lQ==
</ValueDigest>
</Data>
<Data Name="COUNTER">
<Value>AAAAAAAAAAA=</Value>
</Data>
<Expiry>10/30/2012</Expiry>
</Key>
</Device>
</KeyContainer>
</KeyContainer>
<Mac MacAlgorithm="urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes">
miidfasde312asder394jw==
</Mac>
<AuthenticationData>
<AuthenticationCodeMac>
<Mac>4bRJf9xXd3KchKoTenHJiw==</Mac>
</AuthenticationCodeMac>
</AuthenticationData>
</dskpp:KeyProvServerFinished>
7.2.1.3. Example Using the Passphrase-Based Key Wrap Profile
The client sends a request similar to that in Section 7.2.1.1 with
authentication data basing on an authentication code, and the server
responds using the Passphrase-Based Key Wrap Profile. The
authentication data is set in clear text when it is sent over a
secure transport channel such as TLS.
<?xml version="1.0" encoding="UTF-8"?>
<dskpp:KeyProvClientHello Version="1.0"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:pkcs-5="http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5v2-0#"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<DeviceIdentifierData>
<DeviceId>
<pskc:Manufacturer>ManufacturerABC</pskc:Manufacturer>
<pskc:SerialNo>XL0000000001234</pskc:SerialNo>
<pskc:Model>U2</pskc:Model>
</DeviceId>
</DeviceIdentifierData>
<ClientNonce>xwQzwEl0CjPAiQeDxwRJdQ==</ClientNonce>
<SupportedKeyTypes>
<Algorithm>urn:ietf:params:xml:schema:keyprov:otpalg#HOTP</Algorithm>
<Algorithm>
http://www.rsa.com/rsalabs/otps/schemas/2005/09/otps-wst#SecurID-AES
</Algorithm>
</SupportedKeyTypes>
<SupportedEncryptionAlgorithms>
<Algorithm>http://www.w3.org/2001/05/xmlenc#rsa_1_5</Algorithm>
<Algorithm>http://www.w3.org/2001/04/xmlenc#kw-aes128</Algorithm>
<Algorithm>
http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5#pbes2
</Algorithm>
<Algorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</Algorithm>
</SupportedEncryptionAlgorithms>
<SupportedMacAlgorithms>
<Algorithm>
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes
</Algorithm>
</SupportedMacAlgorithms>
<SupportedProtocolVariants>
<TwoPass>
<SupportedKeyInitializationMethod>
urn:ietf:params:xml:schema:keyprov:protocol#wrap
</SupportedKeyInitializationMethod>
<Payload xsi:type="ds:KeyInfoType">
<ds:KeyName>Key_001</ds:KeyName>
</Payload>
<SupportedKeyInitializationMethod>
urn:ietf:params:xml:schema:keyprov:protocol#passphrase-wrap
</SupportedKeyInitializationMethod>
</TwoPass>
</SupportedProtocolVariants>
<SupportedKeyContainers>
<KeyContainerFormat>
urn:ietf:params:xml:schema:keyprov:container#KeyContainer
</KeyContainerFormat>
</SupportedKeyContainers>
<AuthenticationData>
<ClientID>31300257</ClientID>
<AuthenticationCodeMac>
<IterationCount>512</IterationCount>
<Mac>4bRJf9xXd3KchKoTenHJiw==</Mac>
</AuthenticationCodeMac>
</AuthenticationData>
</dskpp:KeyProvClientHello>
In this example, the server responds to the previous request using
the Passphrase-Based Key Wrap Profile.
<?xml version="1.0" encoding="UTF-8"?>
<dskpp:KeyProvServerFinished Version="1.0" SessionID="4114" Status="Success"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:xenc="http://www.w3.org/2001/04/xmlenc#"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<KeyContainer>
<KeyContainer Version="1.0">
<EncryptionMethod
Algorithm="http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5#pbes2"
xmlns="urn:ietf:params:xml:ns:keyprov:1.0:container">
<PBEEncryptionParam
EncryptionAlgorithm="http://www.w3.org/2001/04/xmlenc#kw-aes128-cbc">
<PBESalt>y6TzckeLRQw=</PBESalt>
<PBEIterationCount>1024</PBEIterationCount>
</PBEEncryptionParam>
<IV>c2FtcGxlaXY=</IV>
</EncryptionMethod>
<pskc:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1"/>
<Device xmlns="urn:ietf:params:xml:ns:keyprov:1.0:container">
<Key KeyAlgorithm="urn:ietf:params:xml:schema:keyprov:otpalg#HOTP"
KeyId="SDU312345678">
<Issuer>CredentialIssuer</Issuer>
<Usage otp="true">
<ResponseFormat format="DECIMAL" length="6"/>
</Usage>
<FriendlyName>MyFirstToken</FriendlyName>
<Data Name="SECRET">
<Value>
JSPUyp3azOkqJENSsh6b2hdXz1WBYypzJxEr+ikQAa22M6V/BgZhRg==
</Value>
<ValueDigest>
i8j+kpbfKQsSlwmJYS99lQ==
</ValueDigest>
</Data>
<Data Name="COUNTER">
<Value>AAAAAAAAAAA=</Value>
</Data>
<Expiry>10/30/2012</Expiry>
</Key>
</Device>
</KeyContainer>
</KeyContainer>
<Mac MacAlgorithm="urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes">
miidfasde312asder394jw==
</Mac>
<AuthenticationData>
<AuthenticationCodeMac>
<Mac>4bRJf9xXd3KchKoTenHJiw==</Mac>
</AuthenticationCodeMac>
</AuthenticationData>
</dskpp:KeyProvServerFinished>
7.2.2. Components of the <KeyProvClientHello> Request
The components of this message have the following meaning: The components of this message have the following meaning:
o Version: (attribute inherited from the AbstractRequestType type) o Version: (attribute inherited from the AbstractRequestType type)
The highest version of this protocol the client supports. Only The highest version of this protocol the client supports. Only
version one ("1.0") is currently specified. version one ("1.0") is currently specified.
o <DeviceIdentifierData>: An identifier for the cryptographic module o <DeviceIdentifierData>: An identifier for the cryptographic module
as defined in Section 4.3.1 above. The identifier MUST only be as defined in Section 5.3 above. The identifier MUST only be
present if such shared secrets exist or if the identifier was present if such shared secrets exist or if the identifier was
provided by the server in a <DSKPPTrigger> element (see provided by the server in a <KeyProvTrigger> element (see
Section 5.2.7 below). In the latter case, it MUST have the same Section 12.2.7 below). In the latter case, it MUST have the same
value as the identifier provided in that element. value as the identifier provided in that element.
o <KeyID>: An identifier for the key that will be overwritten if the o <KeyID>: An identifier for the key that will be overwritten if the
protocol run is successful. The identifier MUST only be present protocol run is successful. The identifier MUST only be present
if the key exists or was provided by the server in a if the key exists or the identifier was provided by the server in
<DSKPPTrigger> element (see Section 5.2.7 below). In the latter a <KeyProvTrigger> element (see Section 12.2.7 below). In the
case, it MUST have the same value as the identifier provided in latter case, it MUST have the same value as the identifier
that element. provided in that element.
o <ClientNonce>: This is the nonce R, which, when present, MUST be
used by the server when calculating MAC values (see below). It is o <KeyProvClientNonce>: This is the nonce R, which, when present,
RECOMMENDED that clients include this element whenever the <KeyID> MUST be used by the server when calculating MAC values (see
element is present. below). It is RECOMMENDED that clients include this element
whenever the <KeyID> element is present.
o <TriggerNonce>: This OPTIONAL element MUST be present if and only o <TriggerNonce>: This OPTIONAL element MUST be present if and only
if the DSKPP run was initialized with a <DSKPPTrigger> message if the DSKPP run was initialized with a <KeyProvTrigger> message
(see Section 5.2.7 below), and MUST, in that case, have the same (see Section 12.2.7 below), and MUST, in that case, have the same
value as the <TriggerNonce> child of that message. A server using value as the <TriggerNonce> child of that message. A server using
nonces in this way MUST verify that the nonce is valid and that nonces in this way MUST verify that the nonce is valid and that
any device or key identifier values provided in the <DSKPPTrigger> any device or key identifier values provided in the
message match the corresponding identifier values in the <KeyProvTrigger> message match the corresponding identifier values
<ClientHello> message. in the <KeyProvClientHello> message.
o <SupportedKeyTypes>: A sequence of URIs indicating the key types o <SupportedKeyTypes>: A sequence of URIs indicating the key types
for which the cryptographic module is willing to generate keys for which the cryptographic module is willing to generate keys
through DSKPP. through DSKPP.
o <SupportedEncryptionAlgorithms>: A sequence of URIs indicating the o <SupportedEncryptionAlgorithms>: A sequence of URIs indicating the
encryption algorithms supported by the cryptographic module for encryption algorithms supported by the cryptographic module for
the purposes of DSKPP. The DSKPP client MAY indicate the same the purposes of DSKPP. The DSKPP client MAY indicate the same
algorithm both as a supported key type and as an encryption algorithm both as a supported key type and as an encryption
algorithm. algorithm.
o <SupportedMACAlgorithms>: A sequence of URIs indicating the MAC o <SupportedMacAlgorithms>: A sequence of URIs indicating the MAC
algorithms supported by the cryptographic module for the purposes algorithms supported by the cryptographic module for the purposes
of DSKPP. The DSKPP client MAY indicate the same algorithm both of DSKPP. The DSKPP client MAY indicate the same algorithm both
as an encryption algorithm and as a MAC algorithm (e.g., as an encryption algorithm and as a MAC algorithm (e.g.,
urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes defined urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes defined
in Appendix E). in Appendix B).
o <SupportedProtocolVariants>: This OPTIONAL element is used by the o <SupportedProtocolVariants>: This OPTIONAL element is used by the
DSKPP client to indicate support for four-pass or two-pass DSKPP. DSKPP client to indicate support for four-pass or two-pass DSKPP.
If two-pass support is specified, then <ClientNonce> MUST be set If two-pass support is specified, then <KeyProvClientNonce> MUST
to nonce R in the <ClientHello> message unless <TriggerNonce> is be set to nonce R in the <KeyProvClientHello> message unless
already present. <TriggerNonce> is already present.
o <SupportedKeyContainers>: This OPTIONAL element is a sequence of o <SupportedKeyContainers>: This OPTIONAL element is a sequence of
URIs indicating the key container formats supported by the DSKPP URIs indicating the key container formats supported by the DSKPP
client. If this element is not provided, then the DSKPP server client. If this element is not provided, then the DSKPP server
MUST proceed with MUST proceed with
"http://www.openauthentication.org/OATH/2006/10/PSKC#KeyContainer" "urn:ietf:params:xml:schema:keyprov:container#KeyContainer" (see
(see [PSKC]. [PSKC].
o <AuthenticationData>: This OPTIONAL element contains data that the o <AuthenticationData>: This OPTIONAL element contains data that the
DSKPP client uses to authenticate the user or device to the DSKPP DSKPP client uses to authenticate the user or device to the DSKPP
server. The element is set as specified in Section 4.3.1. server. The element is set as specified in Section 5.3.
o <Extensions>: A sequence of extensions. One extension is defined o <Extensions>: A sequence of extensions. One extension is defined
for this message in this version of DSKPP: the ClientInfoType (see for this message in this version of DSKPP: the ClientInfoType (see
Section 4.11). Section 10).
4.10.4. The DSKPP Server's Initial PDU (4-Pass Only) 7.2.3. Components of a <KeyProvServerFinished> Response
This message is the first message sent from the DSKPP server to the This message is the last message of the DSKPP protocol run. In a
DSKPP client (assuming a trigger message has not been sent to 4-pass exchange, the DSKPP server sends this message in response to a
initiate the protocol, in which case, this message is the second <KeyProvClientNonce> message, whereas in a 2-pass exchange, the DSKPP
message sent from the DSKPP server to the DSKPP client). It is sent server sends this message in response to a <KeyProvClientHello>
upon reception of a <ClientHello> message. message. In a 1-pass exchange, the DSKPP server sends only this
message to the client. The components of this message have the
following meaning:
<xs:element name="ServerHello" type="ServerHelloPDU"/> o Version: (inherited from the AbstractResponseType type) The DSKPP
version used in this session.
o SessionID: (inherited from the AbstractResponseType type) The
previously established identifier for this session.
o Status: (inherited from the AbstractResponseType type) Return code
for the <KeyProvServerFinished> message. If Status is not
"Success", only the Status, SessionID, and Version attributes will
be present (the presence of the SessionID attribute is dependent
on the type of reported error); otherwise, all the other elements
MUST be present as well. In this latter case, the
<KeyProvServerFinished> message can be seen as a "Commit" message,
instructing the cryptographic module to store the generated key
and associate the given key identifier with this key.
o <KeyContainer>: The key container containing symmetric key values
(in the case of a 2- or 1-pass exchange) and configuration data.
The default container format is based on the KeyContainerType type
from PSKC, as defined in [PSKC].
o <Extensions>: A list of extensions chosen by the DSKPP server.
For this message, this version of DSKPP defines one extension, the
ClientInfoType (see Section 10).
o <Mac>: To avoid a false "Commit" message causing the cryptographic
module to end up in an initialized state for which the server does
not know the stored key, <KeyProvServerFinished> messages MUST
always be authenticated with a MAC. The MAC MUST be made using
the already established MAC algorithm.
o <AuthenticationData>: This OPTIONAL element contains data that
allows the DSKPP client to authenticate the DSKPP server. The MAC
value is calculated with K_MAC' as specified in Section 4.4.3.
When receiving a <KeyProvServerFinished> message with
Status="Success" for which the MAC verifies, the DSKPP client MUST
associate the generated key K_TOKEN with the provided key
identifier and store this data permanently. After this operation,
it MUST not be possible to overwrite the key unless knowledge of
an authorizing key is proven through a MAC on a later
<KeyProvServerHello> (and <KeyProvServerFinished>) message.
The DSKPP client MUST verify the MAC. The DSKPP client MUST
terminate the DSKPP session if the MAC does not verify, and MUST,
in this case, also delete any nonces, keys, and/or secrets
associated with the failed run of the DSKPP protocol.
The MacType's MacAlgorithm attribute MUST, when present, identify
the negotiated MAC algorithm.
<xs:complexType name="ServerHelloPDU"> 7.3. DSKPP Server Results: The StatusCode Type
<xs:annotation>
<xs:documentation xml:lang="en">
Message sent from DSKPP server to DSKPP client
in response to a received ClientHello PDU.
</xs:documentation>
</xs:annotation>
<xs:complexContent>
<xs:extension base="AbstractResponseType">
<xs:sequence minOccurs="0">
<xs:element name="KeyType"
type="dskpp:AlgorithmType"/>
<xs:element name="EncryptionAlgorithm"
type="dskpp:AlgorithmType"/>
<xs:element name="MacAlgorithm"
type="dskpp:AlgorithmType"/>
<xs:element name="EncryptionKey"
type="ds:KeyInfoType"/>
<xs:element name="KeyContainerFormat"
type="dskpp:KeyContainerFormatType"/>
<xs:element name="Payload"
type="dskpp:PayloadType"/>
<xs:element name="Extensions"
type="dskpp:ExtensionsType" minOccurs="0"/>
<xs:element name="Mac" type="dskpp:MacType"
minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
The components of this message have the following meaning: The StatusCode type enumerates all possible return codes. Upon
transmission or receipt of a message for which the Status attribute's
value is not "Success" or "Continue", the default behavior, unless
explicitly stated otherwise below, is that both the DSKPP server and
the DSKPP client MUST immediately terminate the DSKPP session. DSKPP
servers and DSKPP clients MUST delete any secret values generated as
a result of failed runs of the DSKPP protocol. Session identifiers
MAY be retained from successful or failed protocol runs for replay
detection purposes, but such retained identifiers MUST not be reused
for subsequent runs of the protocol.
o Version: (attribute inherited from the AbstractResponseType type) When possible, the DSKPP client SHOULD present an appropriate error
The version selected by the DSKPP server. MAY be lower than the message to the user.
version indicated by the DSKPP client, in which case, local policy
at the client MUST determine whether or not to continue the
session.
o SessionID: (attribute inherited from the AbstractResponseType
type) An identifier for this session.
o Status: (attribute inherited from the AbstractResponseType type)
Return code for the <ClientHello>. If Status is not "Continue",
only the Status and Version attributes will be present; otherwise,
all the other element MUST be present as well.
o <KeyType>: The type of the key to be generated.
o <EncryptionAlgorithm>: The encryption algorithm to use when
protecting R_C.
o <MacAlgorithm>: The MAC algorithm to be used by the DSKPP server.
o <EncryptionKey>: Information about the key to use when encrypting
R_C. It will either be the server's public key (the <ds:KeyValue>
alternative of ds:KeyInfoType) or an identifier for a shared
secret key (the <ds:KeyName> alternative of ds:KeyInfoType).
o <KeyContainerFormat>: The key container format type to be used by
the DSKPP server. The default setting relies on the
KeyContainerType element defined in
"urn:ietf:params:xml:schema:keyprov:container" [PSKC].
o <Payload>: The actual payload. For this version of the protocol,
only one payload is defined: the pseudorandom string R_S.
o <Extensions>: A list of server extensions. Two extensions are
defined for this message in this version of DSKPP: the
ClientInfoType and the ServerInfoType (see Section 4.11).
o <Mac>: The MAC MUST be present if the DSKPP run will result in the
replacement of an existing symmetric key with a new one (i.e., if
the <KeyID> element was present in the <ClientHello message). In
this case, the DSKPP server MUST prove to the cryptographic module
that it is authorized to replace it. The MAC value MUST be
computed as defined in Section 4.8.1.1.
The DSKPP client MUST verify the MAC if the successful execution
of the protocol will result in the replacement of an existing
symmetric key with a newly generated one. The DSKPP client MUST
terminate the DSKPP session if the MAC does not verify, and MUST
delete any nonces, keys, and/or secrets associated with the failed
run of the DSKPP protocol.
The MacType's MacAlgorithm attribute MUST, when present, identify
the negotiated MAC algorithm.
4.10.5. The DSKPP Client's Second PDU (4-Pass Only) These status codes are valid in all DSKPP Response messages unless
explicitly stated otherwise:
o "Continue" indicates that the DSKPP server is ready for a
subsequent request from the DSKPP client. It cannot be sent in
the server's final message.
o "Success" indicates successful completion of the DSKPP session.
It can only be sent in the server's final message.
o "Abort" indicates that the DSKPP server rejected the DSKPP
client's request for unspecified reasons.
o "AccessDenied" indicates that the DSKPP client is not authorized
to contact this DSKPP server.
o "MalformedRequest" indicates that the DSKPP server failed to parse
the DSKPP client's request.
o "UnknownRequest" indicates that the DSKPP client made a request
that is unknown to the DSKPP server.
o "UnknownCriticalExtension" indicates that a critical DSKPP
extension (see below) used by the DSKPP client was not supported
or recognized by the DSKPP server.
o "UnsupportedVersion" indicates that the DSKPP client used a DSKPP
protocol version not supported by the DSKPP server. This error is
only valid in the DSKPP server's first response message.
o "NoSupportedKeyTypes" indicates that the DSKPP client only
suggested key types that are not supported by the DSKPP server.
This error is only valid in the DSKPP server's first response
message.
o "NoSupportedEncryptionAlgorithms" indicates that the DSKPP client
only suggested encryption algorithms that are not supported by the
DSKPP server. This error is only valid in the DSKPP server's
first response message. Note that the error will only occur if
the DSKPP server does not support any of the DSKPP client's
suggested encryption algorithms.
This message contains the nonce chosen by the cryptographic module, o "NoSupportedMacAlgorithms" indicates that the DSKPP client only
R_C, encrypted by the specified encryption key and encryption suggested MAC algorithms that are not supported by the DSKPP
algorithm. server. This error is only valid in the DSKPP server's first
response message. Note that the error will only occur if the
DSKPP server does not support any of the DSKPP client's suggested
MAC algorithms.
o "NoProtocolVariants" indicates that the DSKPP client only
suggested a protocol variant (either 2-pass or 4-pass) that is not
supported by the DSKPP server. This error is only valid in the
DSKPP server's first response message. Note that the error will
only occur if the DSKPP server does not support any of the DSKPP
client's suggested protocol variants.
o "NoSupportedKeyContainers" indicates that the DSKPP client only
suggested key container formats that are not supported by the
DSKPP server. This error is only valid in the DSKPP server's
first response message. Note that the error will only occur if
the DSKPP server does not support any of the DSKPP client's
suggested key container formats.
o "AuthenticationDataMissing" indicates that the DSKPP client didn't
provide authentication data that the DSKPP server required.
o "AuthenticationDataInvalid" indicates that the DSKPP client
supplied user or device authentication data that the DSKPP server
failed to validate.
o "InitializationFailed" indicates that the DSKPP server could not
generate a valid key given the provided data. When this status
code is received, the DSKPP client SHOULD try to restart DSKPP, as
it is possible that a new run will succeed.
o "ProvisioningPeriodExpired" indicates that the provisioning period
set by the DSKPP server has expired. When the status code is
received, the DSKPP client SHOULD report the key initialization
failure reason to the user and the user MUST register with the
DSKPP server to initialize a new key.
<xs:element name="ClientNonce" type="ClientNoncePDU"/> 8. One-Pass Protocol
<xs:complexType name="ClientNoncePDU"> In this section, example messages are used to describe parameters,
<xs:annotation> encoding and semantics in a 1-pass DSKPP protocol. The examples are
<xs:documentation xml:lang="en"> written using XML. While they are syntactically correct, MAC and
Second message sent from DSKPP client to cipher values are fictitious.
DSKPP server in a DSKPP session.
</xs:documentation>
</xs:annotation>
<xs:complexContent>
<xs:extension base="AbstractRequestType">
<xs:sequence>
<xs:element name="EncryptedNonce"
type="xs:base64Binary"/>
<xs:element name="AuthenticationData"
type="dskpp:AuthenticationDataType" minOccurs="0"/>
<xs:element name="Extensions"
type="dskpp:ExtensionsType" minOccurs="0"/>
</xs:sequence>
<xs:attribute name="SessionID" type="dskpp:IdentifierType"
use="required"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
The components of this message have the following meaning: 8.1. XML Basics
o Version: (inherited from the AbstractRequestType type) MUST be the The DSKPP XML schema can be found in Section 13. Some DSKPP elements
same version as in the <ServerHello> message. rely on the parties being able to compare received values with stored
o <SessionID>: MUST have the same value as the SessionID attribute values. Unless otherwise noted, all elements in this document that
in the received <ServerHello> message. have the XML Schema "xs:string" type, or a type derived from it, MUST
o <EncryptedNonce>: The nonce generated and encrypted by the be compared using an exact binary comparison. In particular, DSKPP
cryptographic module. The encryption MUST be made using the implementations MUST NOT depend on case-insensitive string
selected encryption algorithm and identified key, and as specified comparisons, normalization or trimming of white space, or conversion
in Section 4.5. of locale-specific formats such as numbers.
o <AuthenticationData>: The authentication data value, which MAY
OPTIONALLY be the same as provided in the <ClientHello>, MUST be
set as specified in Section 4.3.1.
o <Extensions>: A list of extensions. Two extensions are defined
for this message in this version of DSKPP: the ClientInfoType and
the ServerInfoType (see Section 4.11).
4.10.6. The DSKPP Server's Final PDU (1-, 2-, and 4-Pass) Implementations that compare values that are represented using
different character encodings MUST use a comparison method that
returns the same result as converting both values to the Unicode
character encoding, Normalization Form C [UNICODE], and then
performing an exact binary comparison.
This message is the last message of the DSKPP protocol run. In a No collation or sorting order for attributes or element values is
4-pass exchange, the DSKPP server sends this message in response to a defined. Therefore, DSKPP implementations MUST NOT depend on
<ClientNonce> message, whereas in a 2-pass exchange, the DSKPP server specific sorting orders for values.
sends this message in response to a <ClientHello> message. In a
1-pass exchange, the DSKPP server sends only this message to the
client.
<xs:element name="ServerFinished" type="ServerFinishedPDU"/> 8.2. Server to Client Only: <KeyProvServerFinished>
<xs:complexType name="ServerFinishedPDU"> 8.2.1. Example
<xs:annotation>
<xs:documentation xml:lang="en">
Final message sent from DSKPP server to
DSKPP client in a DSKPP session.
</xs:documentation>
</xs:annotation>
<xs:complexContent>
<xs:extension base="AbstractResponseType">
<xs:sequence minOccurs="0">
<xs:element name="KeyContainer"
type="dskpp:KeyContainerType"/>
<xs:element name="Extensions"
type="dskpp:ExtensionsType" minOccurs="0"/>
<xs:element name="Mac"
type="dskpp:MacType"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
The components of this message have the following meaning: The Server sends a provisioned key to a client with prior knowledge
about the client's capabilities:
<?xml version="1.0" encoding="UTF-8"?>
<dskpp:KeyProvServerFinished Version="1.0" SessionID="4114" Status="Success"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:xenc="http://www.w3.org/2001/04/xmlenc#"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<KeyContainer>
<KeyContainer Version="1.0">
<pskc:EncryptionMethod
Algorithm="http://www.w3.org/2001/05/xmlenc#rsa_1_5">
<pskc:KeyInfo>
<ds:X509Data>
<ds:X509Certificate>miib</ds:X509Certificate>
</ds:X509Data>
</pskc:KeyInfo>
</pskc:EncryptionMethod>
<pskc:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#hmac-sha1"/>
<Device xmlns="urn:ietf:params:xml:ns:keyprov:1.0:container">
<Key KeyAlgorithm="urn:ietf:params:xml:schema:keyprov:otpalg#HOTP"
KeyId="SDU312345678">
<Issuer>CredentialIssuer</Issuer>
<Usage otp="true">
<ResponseFormat format="DECIMAL" length="6"/>
</Usage>
<FriendlyName>MyFirstToken</FriendlyName>
<Data Name="SECRET">
<Value>
7JHUyp3azOkqJENSsh6b2vxXzwGBYypzJxEr+ikQAa229KV/BgZhGA==
</Value>
<ValueDigest>
i8j+kpbfKQsSlwmJYS99lQ==
</ValueDigest>
</Data>
<Data Name="COUNTER">
<Value>AAAAAAAAAAA=</Value>
</Data>
<Expiry>10/30/2009</Expiry>
</Key>
</Device>
</KeyContainer>
</KeyContainer>
<Mac MacAlgorithm="urn:ietf:params:xml:schema:keyprov:protocol#dskpp-prf-aes">
miidfasde312asder394jw==
</Mac>
<AuthenticationData>
<AuthenticationCodeMac>
<Mac>4bRJf9xXd3KchKoTenHJiw==</Mac>
</AuthenticationCodeMac>
</AuthenticationData>
</dskpp:KeyProvServerFinished>
8.2.2. Components of a <KeyProvServerFinished> Response
This message is the last message of the DSKPP protocol run. In a
4-pass exchange, the DSKPP server sends this message in response to a
<KeyProvClientNonce> message, whereas in a 2-pass exchange, the DSKPP
server sends this message in response to a <KeyProvClientHello>
message. In a 1-pass exchange, the DSKPP server sends only this
message to the client. The components of this message have the
following meaning:
o Version: (inherited from the AbstractResponseType type) The DSKPP o Version: (inherited from the AbstractResponseType type) The DSKPP
version used in this session. version used in this session.
o SessionID: (inherited from the AbstractResponseType type) The o SessionID: (inherited from the AbstractResponseType type) The
previously established identifier for this session. previously established identifier for this session.
o Status: (inherited from the AbstractResponseType type) Return code o Status: (inherited from the AbstractResponseType type) Return code
for the <ServerFinished> message. If Status is not "Success", for the <KeyProvServerFinished> message. If Status is not
only the Status, SessionID, and Version attributes will be present "Success", only the Status, SessionID, and Version attributes will
(the presence of the SessionID attribute is dependent on the type be present (the presence of the SessionID attribute is dependent
of reported error); otherwise, all the other elements MUST be on the type of reported error); otherwise, all the other elements
present as well. In this latter case, the <ServerFinished> MUST be present as well. In this latter case, the
message can be seen as a "Commit" message, instructing the <KeyProvServerFinished> message can be seen as a "Commit" message,
cryptographic module to store the generated key and associate the instructing the cryptographic module to store the generated key
given key identifier with this key. and associate the given key identifier with this key.
o <KeyContainer>: The key container containing symmetric key values o <KeyContainer>: The key container containing symmetric key values
(in the case of a 2- or 1-pass exchange) and configuration data. (in the case of a 2- or 1-pass exchange) and configuration data.
The default container format is based on the KeyContainerType type The default container format is based on the KeyContainerType type
from PSKC, as defined in [PSKC]. from PSKC, as defined in [PSKC].
o <Extensions>: A list of extensions chosen by the DSKPP server. o <Extensions>: A list of extensions chosen by the DSKPP server.
For this message, this version of DSKPP defines one extension, the For this message, this version of DSKPP defines one extension, the
ClientInfoType (see Section 4.11). ClientInfoType (see Section 10).
o <Mac>: To avoid a false "Commit" message causing the cryptographic o <Mac>: To avoid a false "Commit" message causing the cryptographic
module to end up in an initialized state for which the server does module to end up in an initialized state for which the server does
not know the stored key, <ServerFinished> messages MUST always be not know the stored key, <KeyProvServerFinished> messages MUST
authenticated with a MAC. The MAC MUST be made using the already always be authenticated with a MAC. The MAC MUST be made using
established MAC algorithm. The MAC value MUST be computed as the already established MAC algorithm.
specified in Section 4.8.1.2. o <AuthenticationData>: This OPTIONAL element contains data that
When receiving a <ServerFinished> message with Status="Success" allows the DSKPP client to authenticate the DSKPP server. The MAC
for which the MAC verifies, the DSKPP client MUST associate the value is calculated with K_MAC' as specified in Section 4.5.3.
generated key K_TOKEN with the provided key identifier and store When receiving a <KeyProvServerFinished> message with
this data permanently. After this operation, it MUST not be Status="Success" for which the MAC verifies, the DSKPP client MUST
possible to overwrite the key unless knowledge of an authorizing associate the generated key K_TOKEN with the provided key
key is proven through a MAC on a later <ServerHello> (and identifier and store this data permanently. After this operation,
<ServerFinished>) message. it MUST not be possible to overwrite the key unless knowledge of
an authorizing key is proven through a MAC on a later
<KeyProvServerHello> (and <KeyProvServerFinished>) message.
The DSKPP client MUST verify the MAC. The DSKPP client MUST The DSKPP client MUST verify the MAC. The DSKPP client MUST
terminate the DSKPP session if the MAC does not verify, and MUST, terminate the DSKPP session if the MAC does not verify, and MUST,
in this case, also delete any nonces, keys, and/or secrets in this case, also delete any nonces, keys, and/or secrets
associated with the failed run of the DSKPP protocol. associated with the failed run of the DSKPP protocol.
The MacType's MacAlgorithm attribute MUST, when present, identify The MacType's MacAlgorithm attribute MUST, when present, identify
the negotiated MAC algorithm. the negotiated MAC algorithm.
4.11. Protocol Extensions 9. Trigger
4.11.1. The ClientInfoType Type In this section, an example is used to describe parameters, encoding
and semantics in a DSKPP Trigger message. The example is written
using XML.
When present in a <ClientHello> or a <ClientNonce> message, the 9.1. XML Basics
OPTIONAL ClientInfoType extension contains DSKPP client-specific
The DSKPP XML schema can be found in Section 13. Some DSKPP elements
rely on the parties being able to compare received values with stored
values. Unless otherwise noted, all elements in this document that
have the XML Schema "xs:string" type, or a type derived from it, MUST
be compared using an exact binary comparison. In particular, DSKPP
implementations MUST NOT depend on case-insensitive string
comparisons, normalization or trimming of white space, or conversion
of locale-specific formats such as numbers.
Implementations that compare values that are represented using
different character encodings MUST use a comparison method that
returns the same result as converting both values to the Unicode
character encoding, Normalization Form C [UNICODE], and then
performing an exact binary comparison.
No collation or sorting order for attributes or element values is
defined. Therefore, DSKPP implementations MUST NOT depend on
specific sorting orders for values.
9.2. Example
<dskpp:KeyProvTrigger Version="1.0"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:keyprov:1.0:protocol
keyprov-dskpp-1.0.xsd">
<InitializationTrigger>
<DeviceIdentifierData>
<DeviceId>
<pskc:Manufacturer>ManufacturerABC</pskc:Manufacturer>
<pskc:SerialNo>XL0000000001234</pskc:SerialNo>
<pskc:Model>U2</pskc:Model>
</DeviceId>
</DeviceIdentifierData>
<KeyID>SE9UUDAwMDAwMDAx</KeyID>
<TokenPlatformInfo KeyLocation="Hardware" AlgorithmLocation="Software"/>
<TriggerNonce>112dsdfwf312asder394jw==</TriggerNonce>
<DSKPPServerUrl>https://www.somekeyprovservice.com/</DSKPPServerUrl>
</InitializationTrigger>
</dskpp:KeyProvTrigger>
9.3. Components of the <KeyProvTrigger> Message
The DSKPP server MAY initialize the DSKPP protocol by sending a
<KeyProvTrigger> message. This message MAY, e.g., be sent in
response to a user requesting key initialization in a browsing
session.
The <KeyProvTrigger> element is intended for the DSKPP client and MAY
inform the DSKPP client about the identifier for the device that
houses the cryptographic module to be initialized, and optionally of
the identifier for the key on that module. The latter would apply to
key renewal. The trigger always contains a nonce to allow the DSKPP
server to couple the trigger with a later DSKPP <KeyProvClientHello>
request. Finally, the trigger MAY contain a URL to use when
contacting the DSKPP server. The <xs:any> elements are for future
extensibility. Any provided <DeviceIdentifierData> or <KeyID> values
MUST be used by the DSKPP client in the subsequent
<KeyProvClientHello> request. The OPTIONAL <TokenPlatformInfo>
element informs the DSKPP client about the characteristics of the
intended cryptographic module platform, and applies in the public-key
variant of DSKPP in situations when the client potentially needs to
decide which one of several modules to initialize.
10. Extensibility
10.1. The ClientInfoType Type
present in a <KeyProvClientHello> or a <KeyProvClientNonce> message,
the OPTIONAL ClientInfoType extension contains DSKPP client-specific
information. DSKPP servers MUST support this extension. DSKPP information. DSKPP servers MUST support this extension. DSKPP
servers MUST NOT attempt to interpret the data it carries and, if servers MUST NOT attempt to interpret the data it carries and, if
received, MUST include it unmodified in the current protocol run's received, MUST include it unmodified in the current protocol run's
next server response. Servers need not retain the ClientInfoType's next server response. Servers need not retain the ClientInfoType's
data after that response has been generated. data after that response has been generated.
<xs:complexType name="ClientInfoType"> 10.2. The ServerInfoType Type
<xs:complexContent>
<xs:extension base="AbstractExtensionType">
<xs:sequence>
<xs:element name="Data"
type="xs:base64Binary"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
4.11.2. The ServerInfoType Type
When present, the OPTIONAL ServerInfoType extension contains DSKPP When present, the OPTIONAL ServerInfoType extension contains DSKPP
server-specific information. This extension is only valid in server-specific information. This extension is only valid in
<ServerHello> messages for which Status = "Continue". DSKPP clients <KeyProvServerHello> messages for which Status = "Continue". DSKPP
MUST support this extension. DSKPP clients MUST NOT attempt to clients MUST support this extension. DSKPP clients MUST NOT attempt
interpret the data it carries and, if received, MUST include it to interpret the data it carries and, if received, MUST include it
unmodified in the current protocol run's next client request (i.e., unmodified in the current protocol run's next client request (i.e.,
the <ClientNonce> message). DSKPP clients need not retain the the <KeyProvClientNonce> message). DSKPP clients need not retain the
ServerInfoType's data after that request has been generated. This ServerInfoType's data after that request has been generated. This
extension MAY be used, e.g., for state management in the DSKPP extension MAY be used, e.g., for state management in the DSKPP
server. server.
<xs:complexType name="ServerInfoType"> 10.3. The KeyInitializationDataType Type
<xs:complexContent>
<xs:extension base="AbstractExtensionType">
<xs:sequence>
<xs:element name="Data"
type="xs:base64Binary"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
4.11.3. The KeyInitializationDataType Type
This extension is used for 2- and 1-pass DSKPP exchange; it carries This extension is used for 2- and 1-pass DSKPP exchange; it carries
an identifier for the selected key initialization method as well as an identifier for the selected key initialization method as well as
key initialization method-dependent payload data. key initialization method-dependent payload data.
Servers MAY include this extension in a <ServerFinished> message that Servers MAY include this extension in a <KeyProvServerFinished>
is being sent in response to a received <ClientHello> message if and message that is being sent in response to a received
only if that <ClientHello> message selected TwoPassSupport as the <KeyProvClientHello> message if and only if that <KeyProvClientHello>
ProtocolVariantType and the client indicated support for the selected message selected TwoPassSupport as the ProtocolVariantType and the
key initialization method. Servers MUST include this extension in a client indicated support for the selected key initialization method.
<ServerFinished> message that is sent as part of a 1-pass DSKPP. Servers MUST include this extension in a <KeyProvServerFinished>
message that is sent as part of a 1-pass DSKPP.
<xs:complexType name="KeyInitializationDataType">
<xs:annotation>
<xs:documentation xml:lang="en">
This extension is only valid in ServerFinished PDUs. It
contains key initialization data and its presence results in a
two-pass (or one-pass, if no ClientHello was sent) DSKPP
exchange.
</xs:documentation>
</xs:annotation>
<xs:complexContent>
<xs:extension base="dskpp:AbstractExtensionType">
<xs:sequence>
<xs:element name="KeyInitializationMethod" type="xs:anyURI"/>
<xs:element name="Payload"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
The elements of this type have the following meaning: The elements of this type have the following meaning:
o <KeyInitializationMethod>: A two-pass key initialization method o <KeyInitializationMethod>: A two-pass key initialization method
supported by the DSKPP client. supported by the DSKPP client.
o <Payload>: A payload associated with the key initialization o <Payload>: A payload associated with the key initialization
method. Since the syntax is a shorthand for <xs:element method. Since the syntax is a shorthand for <xs:element
name="Payload" type="xs:anyType"/>, any well-formed payloads can name="Payload" type="xs:anyType"/>, any well-formed payloads can
be carried in this element. be carried in this element.
5. Protocol Bindings 11. Key Initialization Profiles of Two- and One-Pass DSKPP
5.1. General Requirements 11.1. Introduction
This appendix introduces three profiles of DSKPP for key
initialization. They MAY all be used for two- as well as one-pass
initialization of cryptographic modules. Further profiles MAY be
defined by external entities or through the IETF process.
11.2. Key Transport Profile
11.2.1. Introduction
This profile initializes the cryptographic module with a symmetric
key, K_TOKEN, through key transport and key derivation. The key
transport is carried out using a public key, K_CLIENT, whose private
key part resides in the cryptographic module as the transport key. A
key K from which two keys, K_TOKEN and K_MAC are derived MUST be
transported.
11.2.2. Identification
This profile MUST be identified with the following URN:
urn:ietf:params:xml:schema:keyprov:protocol#transport
11.2.3. Payloads
In the two-pass version of DSKPP, the client MUST send a payload
associated with this key initialization method. The payload MUST be
of type ds:KeyInfoType ([XMLDSIG]), and only those choices of the ds:
KeyInfoType that identify a public key are allowed. The ds:
X509Certificate option of the ds:X509Data alternative is RECOMMENDED
when the public key corresponding to the private key on the
cryptographic module has been certified.
The server payload associated with this key initialization method
MUST be of type xenc:EncryptedKeyType ([XMLENC]), and only those
encryption methods utilizing a public key that are supported by the
DSKPP client (as indicated in the <SupportedEncryptionAlgorithms>
element of the <KeyProvClientHello> message in the case of 2-pass
DSKPP, or as otherwise known in the case of 1-pass DSKPP) are allowed
as values for the <xenc:EncryptionMethod> element. Further, in the
case of 2-pass DSKPP, the <ds:KeyInfo> element MUST contain the same
value (i.e. identify the same public key) as the <Payload> of the
corresponding supported key initialization method in the
<KeyProvClientHello> message that triggered the response. The
<CarriedKeyName> element MAY be present, but MUST, when present,
contain the same value as the <KeyID> element of the
<KeyProvServerFinished> message. The Type attribute of the xenc:
EncryptedKeyType MUST be present and MUST identify the type of the
wrapped key. The type MUST be one of the types supported by the
DSKPP client (as reported in the <SupportedKeyTypes> of the preceding
<KeyProvClientHello> message in the case of 2-pass DSKPP, or as
otherwise known in the case of 1-pass DSKPP). The transported key
MUST consist of two parts of equal length. The first half
constitutes K_MAC and the second half constitutes K_TOKEN. The
length of K_TOKEN (and hence also the length of K_MAC) is determined
by the type of K_TOKEN.
DSKPP servers and cryptographic modules supporting this profile MUST
support the http://www.w3.org/2001/04/xmlenc#rsa-1_5 key-wrapping
mechanism defined in [XMLENC].
When this profile is used, the MacAlgorithm attribute of the <Mac>
element of the <KeyProvServerFinished> message MUST be present and
MUST identify the selected MAC algorithm. The selected MAC algorithm
MUST be one of the MAC algorithms supported by the DSKPP client (as
indicated in the <SupportedMacAlgorithms> element of the
<KeyProvClientHello> message in the case of 2-pass DSKPP, or as
otherwise known in the case of 1-pass DSKPP). The MAC MUST be
calculated as described in Section 4.4 for Two-Pass DSKPP and
Section 4.5 for One-Pass DSKPP.
In addition, DSKPP servers MUST include the AuthenticationDataType
element in their <KeyProvServerFinished> messages whenever a
successful protocol run will result in an existing K_TOKEN being
replaced.
11.3. Key Wrap Profile
11.3.1. Introduction
This profile initializes the cryptographic module with a symmetric
key, K_TOKEN, through key wrap and key derivation. The key wrap MUST
be carried out using a (symmetric) key-wrapping key, K_SHARED, known
in advance by both the cryptographic module and the DSKPP server. A
key K from which two keys, K_TOKEN and K_MAC are derived MUST be
wrapped.
11.3.2. Identification
This profile MUST be identified with the following URI:
urn:ietf:params:xml:schema:keyprov:protocol#wrap
11.3.3. Payloads
In the 2-pass version of DSKPP, the client MUST send a payload
associated with this key initialization method. The payload MUST be
of type ds:KeyInfoType ([XMLDSIG]), and only those choices of the ds:
KeyInfoType that identify a symmetric key are allowed. The ds:
KeyName alternative is RECOMMENDED.
The server payload associated with this key initialization method
MUST be of type xenc:EncryptedKeyType ([XMLENC]), and only those
encryption methods utilizing a symmetric key that are supported by
the DSKPP client (as indicated in the <SupportedEncryptionAlgorithms>
element of the <KeyProvClientHello> message in the case of 2-pass
DSKPP, or as otherwise known in the case of 1-pass DSKPP) are allowed
as values for the <xenc:EncryptionMethod> element. Further, in the
case of 2-pass DSKPP, the <ds:KeyInfo> element MUST contain the same
value (i.e. identify the same symmetric key) as the <Payload> of the
corresponding supported key initialization method in the
<KeyProvClientHello> message that triggered the response. The
<CarriedKeyName> element MAY be present, and MUST, when present,
contain the same value as the <KeyID> element of the
<KeyProvServerFinished> message. The Type attribute of the xenc:
EncryptedKeyType MUST be present and MUST identify the type of the
wrapped key. The type MUST be one of the types supported by the
DSKPP client (as reported in the <SupportedKeyTypes> of the preceding
<KeyProvClientHello> message in the case of 2-pass DSKPP, or as
otherwise known in the case of 1-pass DSKPP). The wrapped key MUST
consist of two parts of equal length. The first half constitutes
K_MAC and the second half constitutes K_TOKEN. The length of K_TOKEN
(and hence also the length of K_MAC) is determined by the type of
K_TOKEN.
DSKPP servers and cryptographic modules supporting this profile MUST
support the http://www.w3.org/2001/04/xmlenc#kw-aes128 key-wrapping
mechanism defined in [XMLENC].
When this profile is used, the MacAlgorithm attribute of the <Mac>
element of the <KeyProvServerFinished> message MUST be present and
MUST identify the selected MAC algorithm. The selected MAC algorithm
MUST be one of the MAC algorithms supported by the DSKPP client (as
indicated in the <SupportedMacAlgorithms> element of the
<KeyProvClientHello> message in the case of 2-pass DSKPP, or as
otherwise known in the case of 1-pass DSKPP). The MAC MUST be
calculated as described in Section 4.4.
In addition, DSKPP servers MUST include the AuthenticationDataType
element in their <KeyProvServerFinished> messages whenever a
successful protocol run will result in an existing K_TOKEN being
replaced.
11.4. Passphrase-Based Key Wrap Profile
11.4.1. Introduction
This profile is a variation of the key wrap profile. It initializes
the cryptographic module with a symmetric key, K_TOKEN, through key
wrap and key derivation, using a passphrase-derived key-wrapping key,
K_DERIVED. The passphrase is known in advance by both the device
user and the DSKPP server. To preserve the property of not exposing
K_TOKEN to any other entity than the DSKPP server and the
cryptographic module itself, the method SHOULD be employed only when
the device contains facilities (e.g. a keypad) for direct entry of
the passphrase. A key K from which two keys, K_TOKEN and K_MAC are
derived MUST be wrapped.
11.4.2. Identification
This profile MUST be identified with the following URI:
urn:ietf:params:xml:schema:keyprov:protocol#passphrase-wrap
11.4.3. Payloads
In the 2-pass version of DSKPP, the client MUST send a payload
associated with this key initialization method. The payload MUST be
of type ds:KeyInfoType ([XMLDSIG]). The ds:KeyName option MUST be
used and the key name MUST identify the passphrase that will be used
by the server to generate the key-wrapping key. As an example, the
identifier could be a user identifier or a registration identifier
issued by the server to the user during a session preceding the DSKPP
protocol run.
The server payload associated with this key initialization method
MUST be of type xenc:EncryptedKeyType ([XMLENC]), and only those
encryption methods utilizing a passphrase to derive the key-wrapping
key that are supported by the DSKPP client (as indicated in the
<SupportedEncryptionAlgorithms> element of the <KeyProvClientHello>
message in the case of 2-pass DSKPP, or as otherwise known in the
case of 1-pass DSKPP) are allowed as values for the <xenc:
EncryptionMethod> element. Further, in the case of 2-pass DSKPP, the
<ds:KeyInfo> element MUST contain the same value (i.e. identify the
same passphrase) as the <Payload> of the corresponding supported key
initialization method in the <KeyProvClientHello> message that
triggered the response. The <CarriedKeyName> element MAY be present,
and MUST, when present, contain the same value as the <KeyID> element
of the <KeyProvServerFinished> message. The Type attribute of the
xenc:EncryptedKeyType MUST be present and MUST identify the type of
the wrapped key. The type MUST be one of the types supported by the
DSKPP client (as reported in the <SupportedKeyTypes> of the preceding
<KeyProvClientHello> message in the case of 2-pass DSKPP, or as
otherwise known in the case of 1-pass DSKPP). The wrapped key MUST
consist of two parts of equal length. The first half constitutes
K_MAC and the second half constitutes K_TOKEN. The length of K_TOKEN
(and hence also the length of K_MAC) is determined by the type of
K_TOKEN.
DSKPP servers and cryptographic modules supporting this profile MUST
support the PBES2 password based encryption scheme defined in
[PKCS-5] (and identified as
http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5#pbes2 in
[PKCS-5-XML]), the PBKDF2 passphrase-based key derivation function
also defined in [PKCS-5] (and identified as
http://www.rsasecurity.com/rsalabs/pkcs/schemas/pkcs-5#pbkdf2 in
[PKCS-5-XML]), and the http://www.w3.org/2001/04/xmlenc#kw-aes128
key-wrapping mechanism defined in [XMLENC].
When this profile is used, the MacAlgorithm attribute of the <Mac>
element of the <KeyProvServerFinished> message MUST be present and
MUST identify the selected MAC algorithm. The selected MAC algorithm
MUST be one of the MAC algorithms supported by the DSKPP client (as
indicated in the <SupportedMacAlgorithms> element of the
<KeyProvClientHello> message in the case of 2-pass DSKPP, or as
otherwise known in the case of 1-pass DSKPP). The MAC MUST be
calculated as described in Section 4.4.
In addition, DSKPP servers MUST include the AuthenticationDataType
element in their <KeyProvServerFinished> messages whenever a
successful protocol run will result in an existing K_TOKEN being
replaced.
12. Protocol Bindings
12.1. General Requirements
DSKPP assumes a reliable transport. DSKPP assumes a reliable transport.
5.2. HTTP/1.1 Binding for DSKPP 12.2. HTTP/1.1 Binding for DSKPP
5.2.1. Introduction 12.2.1. Introduction
This section presents a binding of the previous messages to HTTP/1.1 This section presents a binding of the previous messages to HTTP/1.1
[RFC2616]. Note that the HTTP client normally will be different from [RFC2616]. Note that the HTTP client normally will be different from
the DSKPP client, i.e., the HTTP client will only exist to "proxy" the DSKPP client, i.e., the HTTP client will only exist to "proxy"
DSKPP messages from the DSKPP client to the DSKPP server. Likewise, DSKPP messages from the DSKPP client to the DSKPP server. Likewise,
on the HTTP server side, the DSKPP server MAY receive DSKPP PDUs from on the HTTP server side, the DSKPP server MAY receive DSKPP PDUs from
a "front-end" HTTP server. a "front-end" HTTP server.
5.2.2. Identification of DSKPP Messages 12.2.2. Identification of DSKPP Messages
The MIME-type for all DSKPP messages MUST be The MIME-type for all DSKPP messages MUST be
application/vnd.ietf.keyprov.dskpp+xml application/vnd.ietf.keyprov.dskpp+xml
5.2.3. HTTP Headers 12.2.3. HTTP Headers
HTTP proxies MUST NOT cache responses carrying DSKPP messages. For HTTP proxies MUST NOT cache responses carrying DSKPP messages. For
this reason, the following holds: this reason, the following holds:
o When using HTTP/1.1, requesters SHOULD: o When using HTTP/1.1, requesters SHOULD:
* Include a Cache-Control header field set to "no-cache, no- * Include a Cache-Control header field set to "no-cache, no-
store". store".
* Include a Pragma header field set to "no-cache". * Include a Pragma header field set to "no-cache".
o When using HTTP/1.1, responders SHOULD: o When using HTTP/1.1, responders SHOULD:
* Include a Cache-Control header field set to "no-cache, no-must- * Include a Cache-Control header field set to "no-cache, no-must-
revalidate, private". revalidate, private".
* Include a Pragma header field set to "no-cache". * Include a Pragma header field set to "no-cache".
* NOT include a Validator, such as a Last-Modified or ETag * NOT include a Validator, such as a Last-Modified or ETag
header. header.
There are no other restrictions on HTTP headers, besides the There are no other restrictions on HTTP headers, besides the
requirement to set the Content-Type header value according to requirement to set the Content-Type header value according to
Section 5.2.2. Section 12.2.2.
5.2.4. HTTP Operations 12.2.4. HTTP Operations
Persistent connections as defined in HTTP/1.1 are assumed but not Persistent connections as defined in HTTP/1.1 are assumed but not
required. DSKPP requests are mapped to HTTP POST operations. DSKPP required. DSKPP requests are mapped to HTTP POST operations. DSKPP
responses are mapped to HTTP responses. responses are mapped to HTTP responses.
5.2.5. HTTP Status Codes 12.2.5. HTTP Status Codes
A DSKPP HTTP responder that refuses to perform a message exchange A DSKPP HTTP responder that refuses to perform a message exchange
with a DSKPP HTTP requester SHOULD return a 403 (Forbidden) response. with a DSKPP HTTP requester SHOULD return a 403 (Forbidden) response.
In this case, the content of the HTTP body is not significant. In In this case, the content of the HTTP body is not significant. In
the case of an HTTP error while processing a DSKPP request, the HTTP the case of an HTTP error while processing a DSKPP request, the HTTP
server MUST return a 500 (Internal Server Error) response. This type server MUST return a 500 (Internal Server Error) response. This type
of error SHOULD be returned for HTTP-related errors detected before of error SHOULD be returned for HTTP-related errors detected before
control is passed to the DSKPP processor, or when the DSKPP processor control is passed to the DSKPP processor, or when the DSKPP processor
reports an internal error (for example, the DSKPP XML namespace is reports an internal error (for example, the DSKPP XML namespace is
incorrect, or the DSKPP schema cannot be located). If the type of a incorrect, or the DSKPP schema cannot be located). If the type of a
skipping to change at page 54, line 10 skipping to change at page 75, line 29
In these cases (i.e., when the HTTP response code is 4xx or 5xx), the In these cases (i.e., when the HTTP response code is 4xx or 5xx), the
content of the HTTP body is not significant. content of the HTTP body is not significant.
Redirection status codes (3xx) apply as usual. Redirection status codes (3xx) apply as usual.
Whenever the HTTP POST is successfully invoked, the DSKPP HTTP Whenever the HTTP POST is successfully invoked, the DSKPP HTTP
responder MUST use the 200 status code and provide a suitable DSKPP responder MUST use the 200 status code and provide a suitable DSKPP
message (possibly with DSKPP error information included) in the HTTP message (possibly with DSKPP error information included) in the HTTP
body. body.
5.2.6. HTTP Authentication 12.2.6. HTTP Authentication
No support for HTTP/1.1 authentication is assumed. No support for HTTP/1.1 authentication is assumed.
5.2.7. Initialization of DSKPP 12.2.7. Initialization of DSKPP
The DSKPP server MAY initialize the DSKPP protocol by sending an HTTP The DSKPP server MAY initialize the DSKPP protocol by sending an HTTP
response with Content-Type set according to Section 5.2.2 and response with Content-Type set according to Section 12.2.2 and
response code set to 200 (OK). This message MAY, e.g., be sent in response code set to 200 (OK). This message MAY, e.g., be sent in
response to a user requesting key initialization in a browsing response to a user requesting key initialization in a browsing
session. The initialization message MAY carry data in its body. If session. The initialization message MAY carry data in its body. If
this is the case, the data MUST be a valid instance of a this is the case, the data MUST be a valid instance of a
<DSKPPTrigger> element. <KeyProvTrigger> element.
5.2.8. Example Messages 12.2.8. Example Messages
a. Initialization from DSKPP server: a. Initialization from DSKPP server:
HTTP/1.1 200 OK HTTP/1.1 200 OK
Cache-Control: no-store Cache-Control: no-store
Content-Type: application/vnd.ietf.keyprov.dskpp+xml Content-Type: application/vnd.ietf.keyprov.dskpp+xml
Content-Length: <some value> Content-Length: <some value>
DSKPP initialization data in XML form... DSKPP initialization data in XML form...
skipping to change at page 55, line 4 skipping to change at page 76, line 22
DSKPP data in XML form (supported version, supported DSKPP data in XML form (supported version, supported
algorithms...) algorithms...)
c. Initial response from DSKPP server: c. Initial response from DSKPP server:
HTTP/1.1 200 OK HTTP/1.1 200 OK
Cache-Control: no-store Cache-Control: no-store
Content-Type: application/vnd.ietf.keyprov.dskpp+xml Content-Type: application/vnd.ietf.keyprov.dskpp+xml
Content-Length: <some value> Content-Length: <some value>
DSKPP data in XML form (server random nonce, server public key, DSKPP data in XML form (server random nonce, server public key,
...) ...)
6. DSKPP Schema 13. DSKPP Schema
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<xs:schema <xs:schema
targetNamespace="urn:ietf:params:xml:ns:keyprov:protocol" xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
xmlns:dskpp="urn:ietf:params:xml:ns:keyprov:protocol" xmlns:pskc="urn:ietf:params:xml:ns:keyprov:1.0:container"
xmlns:pskc="urn:ietf:params:xml:ns:keyprov:protocol"
xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"> xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
targetNamespace="urn:ietf:params:xml:ns:keyprov:1.0:protocol"
elementFormDefault="unqualified" attributeFormDefault="unqualified"
version="1.0">
<xs:import namespace="http://www.w3.org/2000/09/xmldsig#" <xs:import namespace="http://www.w3.org/2000/09/xmldsig#"
schemaLocation="http://www.w3.org/TR/2002/ schemaLocation="http://www.w3.org/TR/2002/REC-xmldsig-core-20020212/xmldsig-core-schema.xsd"/>
REC-xmldsig-core-20020212/xmldsig-core-schema.xsd"/>
<xs:import namespace="urn:ietf:params:xml:ns:keyprov:1.0:container"
schemaLocation="keyprov-pskc-1.0.xsd"/>
<!-- Basic types --> <!-- Basic types -->
<xs:complexType name="AbstractRequestType" abstract="true"> <xs:complexType name="AbstractRequestType" abstract="true">
<xs:attribute name="Version" type="VersionType" use="required"/> <xs:attribute name="Version" type="dskpp:VersionType" use="required"/>
</xs:complexType> </xs:complexType>
<xs:complexType name="AbstractResponseType" abstract="true"> <xs:complexType name="AbstractResponseType" abstract="true">
<xs:attribute name="Version" type="VersionType" use="required"/> <xs:attribute name="Version" type="dskpp:VersionType" use="required"/>
<xs:attribute name="SessionID" type="IdentifierType"/> <xs:attribute name="SessionID" type="dskpp:IdentifierType"/>
<xs:attribute name="Status" type="StatusCode" use="required"/> <xs:attribute name="Status" type="dskpp:StatusCode" use="required"/>
</xs:complexType> </xs:complexType>
<xs:simpleType name="VersionType"> <xs:simpleType name="VersionType">
<xs:restriction base="xs:string"> <xs:restriction base="xs:string">
<xs:pattern value="\d{1,2}\.\d{1,3}"/> <xs:pattern value="\d{1,2}\.\d{1,3}"/>
</xs:restriction> </xs:restriction>
</xs:simpleType> </xs:simpleType>
<xs:simpleType name="IdentifierType"> <xs:simpleType name="IdentifierType">
<xs:restriction base="xs:string"> <xs:restriction base="xs:string">
skipping to change at page 56, line 11 skipping to change at page 77, line 33
<xs:enumeration value="Continue"/> <xs:enumeration value="Continue"/>
<xs:enumeration value="Success"/> <xs:enumeration value="Success"/>
<xs:enumeration value="Abort"/> <xs:enumeration value="Abort"/>
<xs:enumeration value="AccessDenied"/> <xs:enumeration value="AccessDenied"/>
<xs:enumeration value="MalformedRequest"/> <xs:enumeration value="MalformedRequest"/>
<xs:enumeration value="UnknownRequest"/> <xs:enumeration value="UnknownRequest"/>
<xs:enumeration value="UnknownCriticalExtension"/> <xs:enumeration value="UnknownCriticalExtension"/>
<xs:enumeration value="UnsupportedVersion"/> <xs:enumeration value="UnsupportedVersion"/>
<xs:enumeration value="NoSupportedKeyTypes"/> <xs:enumeration value="NoSupportedKeyTypes"/>
<xs:enumeration value="NoSupportedEncryptionAlgorithms"/> <xs:enumeration value="NoSupportedEncryptionAlgorithms"/>
<xs:enumeration value="NoSupportedMACAlgorithms"/> <xs:enumeration value="NoSupportedMacAlgorithms"/>
<xs:enumeration value="NoProtocolVariants"/> <xs:enumeration value="NoProtocolVariants"/>
<xs:enumeration value="NoSupportedKeyContainers"/> <xs:enumeration value="NoSupportedKeyContainers"/>
<xs:enumeration value="AuthenticationDataMissing"/>
<xs:enumeration value="AuthenticationDataInvalid"/> <xs:enumeration value="AuthenticationDataInvalid"/>
<xs:enumeration value="InitializationFailed"/> <xs:enumeration value="InitializationFailed"/>
</xs:restriction> </xs:restriction>
</xs:simpleType> </xs:simpleType>
<xs:complexType name="DeviceIdentifierDataType"> <xs:complexType name="DeviceIdentifierDataType">
<xs:choice> <xs:choice>
<xs:element name="DeviceID" type="pskc:DeviceIdType"/> <xs:element name="DeviceId" type="pskc:DeviceIdType"/>
<xs:any namespace="##other" processContents="strict"/> <xs:any namespace="##other" processContents="strict"/>
</xs:choice> </xs:choice>
</xs:complexType> </xs:complexType>
<xs:simpleType name="PlatformType"> <xs:simpleType name="PlatformType">
<xs:restriction base="xs:string"> <xs:restriction base="xs:string">
<xs:enumeration value="Hardware"/> <xs:enumeration value="Hardware"/>
<xs:enumeration value="Software"/> <xs:enumeration value="Software"/>
<xs:enumeration value="Unspecified"/> <xs:enumeration value="Unspecified"/>
</xs:restriction> </xs:restriction>
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</xs:complexType> </xs:complexType>
<xs:simpleType name="NonceType"> <xs:simpleType name="NonceType">
<xs:restriction base="xs:base64Binary"> <xs:restriction base="xs:base64Binary">
<xs:minLength value="16"/> <xs:minLength value="16"/>
</xs:restriction> </xs:restriction>
</xs:simpleType> </xs:simpleType>
<xs:complexType name="AlgorithmsType"> <xs:complexType name="AlgorithmsType">
<xs:sequence maxOccurs="unbounded"> <xs:sequence maxOccurs="unbounded">
<xs:element name="Algorithm" type="AlgorithmType"/> <xs:element name="Algorithm" type="dskpp:AlgorithmType"/>
</xs:sequence> </xs:sequence>
</xs:complexType> </xs:complexType>
<xs:simpleType name="AlgorithmType"> <xs:simpleType name="AlgorithmType">
<xs:restriction base="xs:anyURI"/> <xs:restriction base="xs:anyURI"/>
</xs:simpleType> </xs:simpleType>
<xs:complexType name="ProtocolVariantsType"> <xs:complexType name="ProtocolVariantsType">
<xs:sequence> <xs:sequence>
<xs:element name="FourPass" minOccurs="0"/> <xs:element name="FourPass" minOccurs="0"/>
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<xs:sequence maxOccurs="unbounded"> <xs:sequence maxOccurs="unbounded">
<xs:element name="KeyContainerFormat" <xs:element name="KeyContainerFormat"
type="dskpp:KeyContainerFormatType"/> type="dskpp:KeyContainerFormatType"/>
</xs:sequence> </xs:sequence>
</xs:complexType> </xs:complexType>
<xs:simpleType name="KeyContainerFormatType"> <xs:simpleType name="KeyContainerFormatType">
<xs:restriction base="xs:anyURI"/> <xs:restriction base="xs:anyURI"/>
</xs:simpleType> </xs:simpleType>
<xs:complextype name="AuthenticationDataType"> <xs:complexType name="AuthenticationDataType">
<xs:annotation>
<xs:documentation xml:lang="en">
Authentication data can consist of either authentication code
for authenticating a user of the protocol, or an X.509 Certificate for
authenticating a device. When a device certificate is used over a