draft-ietf-httpauth-mutual-03.txt   draft-ietf-httpauth-mutual-04.txt 
HTTPAUTH Working Group Y. Oiwa HTTPAUTH Working Group Y. Oiwa
Internet-Draft H. Watanabe Internet-Draft H. Watanabe
Intended status: Experimental H. Takagi Intended status: Experimental H. Takagi
Expires: February 20, 2015 RISEC, AIST Expires: August 23, 2015 RISEC, AIST
K. Maeda K. Maeda
T. Hayashi T. Hayashi
Lepidum Lepidum
Y. Ioku Y. Ioku
Individual Individual
August 19, 2014 February 19, 2015
Mutual Authentication Protocol for HTTP Mutual Authentication Protocol for HTTP
draft-ietf-httpauth-mutual-03 draft-ietf-httpauth-mutual-04
Abstract Abstract
This document specifies a mutual authentication method for the Hyper- This document specifies a mutual authentication method for the Hyper-
text Transfer Protocol (HTTP). This method provides a true mutual text Transfer Protocol (HTTP). This method provides a true mutual
authentication between an HTTP client and an HTTP server using authentication between an HTTP client and an HTTP server using
password-based authentication. Unlike the Basic and Digest password-based authentication. Unlike the Basic and Digest
authentication methods, the Mutual authentication method specified in authentication methods, the Mutual authentication method specified in
this document assures the user that the server truly knows the user's this document assures the user that the server truly knows the user's
encrypted password. encrypted password.
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 20, 2015. This Internet-Draft will expire on August 23, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Document Structure and Related Documents . . . . . . . . . 5 1.2. Document Structure and Related Documents . . . . . . . . . 5
2. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 5 2. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Messages Overview . . . . . . . . . . . . . . . . . . . . 6 2.1. Messages Overview . . . . . . . . . . . . . . . . . . . . 6
2.2. Typical Flows of the Protocol . . . . . . . . . . . . . . 6 2.2. Typical Flows of the Protocol . . . . . . . . . . . . . . 6
2.3. Alternative Flows . . . . . . . . . . . . . . . . . . . . 9 2.3. Alternative Flows . . . . . . . . . . . . . . . . . . . . 9
3. Message Syntax . . . . . . . . . . . . . . . . . . . . . . . . 10 3. Message Syntax . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1. Values . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.1. Non-ASCII extended header parameters . . . . . . . . . . . 11
3.1.1. Tokens . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2. Values . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.2. Strings . . . . . . . . . . . . . . . . . . . . . . . 12 3.2.1. Tokens . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.3. Numbers . . . . . . . . . . . . . . . . . . . . . . . 12 3.2.2. Strings . . . . . . . . . . . . . . . . . . . . . . . 13
4. Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.2.3. Numbers . . . . . . . . . . . . . . . . . . . . . . . 13
4.1. 401-INIT and 401-STALE . . . . . . . . . . . . . . . . . . 14 4. Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1. 401-INIT and 401-STALE . . . . . . . . . . . . . . . . . . 15
4.2. req-KEX-C1 . . . . . . . . . . . . . . . . . . . . . . . . 17 4.2. req-KEX-C1 . . . . . . . . . . . . . . . . . . . . . . . . 17
4.3. 401-KEX-S1 . . . . . . . . . . . . . . . . . . . . . . . . 17 4.3. 401-KEX-S1 . . . . . . . . . . . . . . . . . . . . . . . . 18
4.4. req-VFY-C . . . . . . . . . . . . . . . . . . . . . . . . 18 4.4. req-VFY-C . . . . . . . . . . . . . . . . . . . . . . . . 19
4.5. 200-VFY-S . . . . . . . . . . . . . . . . . . . . . . . . 19 4.5. 200-VFY-S . . . . . . . . . . . . . . . . . . . . . . . . 20
5. Authentication Realms . . . . . . . . . . . . . . . . . . . . 19 5. Authentication Realms . . . . . . . . . . . . . . . . . . . . 20
5.1. Resolving Ambiguities . . . . . . . . . . . . . . . . . . 21 5.1. Resolving Ambiguities . . . . . . . . . . . . . . . . . . 22
6. Session Management . . . . . . . . . . . . . . . . . . . . . . 22 6. Session Management . . . . . . . . . . . . . . . . . . . . . . 22
7. Host Validation Methods . . . . . . . . . . . . . . . . . . . 23 7. Host Validation Methods . . . . . . . . . . . . . . . . . . . 24
7.1. Applicability notes . . . . . . . . . . . . . . . . . . . 25 7.1. Applicability notes . . . . . . . . . . . . . . . . . . . 26
7.2. Interoperability notes on tls-unique . . . . . . . . . . . 25 7.2. Interoperability notes on tls-unique . . . . . . . . . . . 26
8. Authentication Extensions . . . . . . . . . . . . . . . . . . 26 8. Authentication Extensions . . . . . . . . . . . . . . . . . . 27
9. Decision Procedure for Clients . . . . . . . . . . . . . . . . 26 9. String Preparation . . . . . . . . . . . . . . . . . . . . . . 27
9.1. General Principles and Requirements . . . . . . . . . . . 26 10. Decision Procedure for Clients . . . . . . . . . . . . . . . . 28
9.2. State machine for the client-side . . . . . . . . . . . . 28 10.1. General Principles and Requirements . . . . . . . . . . . 28
10. Decision Procedure for Servers . . . . . . . . . . . . . . . . 33 10.2. State machine for the client-side . . . . . . . . . . . . 29
11. Authentication Algorithms . . . . . . . . . . . . . . . . . . 35 11. Decision Procedure for Servers . . . . . . . . . . . . . . . . 34
11.1. Support Functions and Notations . . . . . . . . . . . . . 36 12. Authentication Algorithms . . . . . . . . . . . . . . . . . . 36
11.2. Default Functions for Algorithms . . . . . . . . . . . . . 37 12.1. Support Functions and Notations . . . . . . . . . . . . . 37
12. Application Channel Binding . . . . . . . . . . . . . . . . . 38 12.2. Default Functions for Algorithms . . . . . . . . . . . . . 38
13. Application for Proxy Authentication . . . . . . . . . . . . . 39 13. Application Channel Binding . . . . . . . . . . . . . . . . . 39
14. Methods to Extend This Protocol . . . . . . . . . . . . . . . 39 14. Application for Proxy Authentication . . . . . . . . . . . . . 40
15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 40 15. Methods to Extend This Protocol . . . . . . . . . . . . . . . 40
16. Security Considerations . . . . . . . . . . . . . . . . . . . 40 16. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 41
16.1. Security Properties . . . . . . . . . . . . . . . . . . . 40 17. Security Considerations . . . . . . . . . . . . . . . . . . . 41
16.2. Denial-of-service Attacks to Servers . . . . . . . . . . . 41 17.1. Security Properties . . . . . . . . . . . . . . . . . . . 41
16.2.1. On-line Active Password Attacks . . . . . . . . . . . 41 17.2. Denial-of-service Attacks to Servers . . . . . . . . . . . 42
16.3. Communicating the status of mutual authentication with 17.2.1. On-line Active Password Attacks . . . . . . . . . . . 42
users . . . . . . . . . . . . . . . . . . . . . . . . . . 42 17.3. Communicating the status of mutual authentication with
16.4. Implementation Considerations . . . . . . . . . . . . . . 42 users . . . . . . . . . . . . . . . . . . . . . . . . . . 43
16.5. Usage Considerations . . . . . . . . . . . . . . . . . . . 43 17.4. Implementation Considerations . . . . . . . . . . . . . . 43
17. Notice on Intellectual Properties . . . . . . . . . . . . . . 43 17.5. Usage Considerations . . . . . . . . . . . . . . . . . . . 44
18. References . . . . . . . . . . . . . . . . . . . . . . . . . . 44 18. Notice on Intellectual Properties . . . . . . . . . . . . . . 44
18.1. Normative References . . . . . . . . . . . . . . . . . . . 44 19. References . . . . . . . . . . . . . . . . . . . . . . . . . . 45
18.2. Informative References . . . . . . . . . . . . . . . . . . 44 19.1. Normative References . . . . . . . . . . . . . . . . . . . 45
Appendix A. (Informative) Draft Remarks from Authors . . . . . . 46 19.2. Informative References . . . . . . . . . . . . . . . . . . 46
Appendix B. (Informative) Draft Change Log . . . . . . . . . . . 46 Appendix A. (Informative) Draft Remarks from Authors . . . . . . 47
B.1. Changes in Httpauth WG Revision 03 . . . . . . . . . . . . 46 Appendix B. (Informative) Draft Change Log . . . . . . . . . . . 47
B.2. Changes in Httpauth WG Revision 02 . . . . . . . . . . . . 46 B.1. Changes in Httpauth WG Revision 04 . . . . . . . . . . . . 47
B.3. Changes in Httpauth WG Revision 01 . . . . . . . . . . . . 47 B.2. Changes in Httpauth WG Revision 03 . . . . . . . . . . . . 48
B.4. Changes in Httpauth Revision 00 . . . . . . . . . . . . . 47 B.3. Changes in Httpauth WG Revision 02 . . . . . . . . . . . . 48
B.5. Changes in HttpBis Revision 00 . . . . . . . . . . . . . . 47 B.4. Changes in Httpauth WG Revision 01 . . . . . . . . . . . . 48
B.6. Changes in Revision 12 . . . . . . . . . . . . . . . . . . 47 B.5. Changes in Httpauth Revision 00 . . . . . . . . . . . . . 48
B.7. Changes in Revision 11 . . . . . . . . . . . . . . . . . . 47 B.6. Changes in HttpBis Revision 00 . . . . . . . . . . . . . . 49
B.8. Changes in Revision 10 . . . . . . . . . . . . . . . . . . 48 B.7. Changes in Revision 12 . . . . . . . . . . . . . . . . . . 49
B.9. Changes in Revision 09 . . . . . . . . . . . . . . . . . . 48 B.8. Changes in Revision 11 . . . . . . . . . . . . . . . . . . 49
B.10. Changes in Revision 08 . . . . . . . . . . . . . . . . . . 49 B.9. Changes in Revision 10 . . . . . . . . . . . . . . . . . . 49
B.11. Changes in Revision 07 . . . . . . . . . . . . . . . . . . 49 B.10. Changes in Revision 09 . . . . . . . . . . . . . . . . . . 50
B.12. Changes in Revision 06 . . . . . . . . . . . . . . . . . . 49 B.11. Changes in Revision 08 . . . . . . . . . . . . . . . . . . 50
B.13. Changes in Revision 05 . . . . . . . . . . . . . . . . . . 50 B.12. Changes in Revision 07 . . . . . . . . . . . . . . . . . . 50
B.14. Changes in Revision 04 . . . . . . . . . . . . . . . . . . 50 B.13. Changes in Revision 06 . . . . . . . . . . . . . . . . . . 51
B.15. Changes in Revision 03 . . . . . . . . . . . . . . . . . . 50 B.14. Changes in Revision 05 . . . . . . . . . . . . . . . . . . 51
B.16. Changes in Revision 02 . . . . . . . . . . . . . . . . . . 50 B.15. Changes in Revision 04 . . . . . . . . . . . . . . . . . . 51
B.17. Changes in Revision 01 . . . . . . . . . . . . . . . . . . 51 B.16. Changes in Revision 03 . . . . . . . . . . . . . . . . . . 52
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 51 B.17. Changes in Revision 02 . . . . . . . . . . . . . . . . . . 52
B.18. Changes in Revision 01 . . . . . . . . . . . . . . . . . . 52
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 52
1. Introduction 1. Introduction
This document specifies a mutual authentication method for Hyper-Text This document specifies a mutual authentication method for Hyper-Text
Transfer Protocol (HTTP). The method, called "Mutual Authentication Transfer Protocol (HTTP). The method, called "Mutual Authentication
Protocol" in this document, provides a true mutual authentication Protocol" in this document, provides a true mutual authentication
between an HTTP client and an HTTP server, using just a simple between an HTTP client and an HTTP server, using just a simple
password as a credential. password as a credential.
The authentication method proposed in this document has the following The authentication method proposed in this document has the following
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This document treats target (codomain) of hash functions to be octet This document treats target (codomain) of hash functions to be octet
strings. The notation INT(H(s)) gives a numerical (natural-number) strings. The notation INT(H(s)) gives a numerical (natural-number)
output of hash function H applied to string s. output of hash function H applied to string s.
1.2. Document Structure and Related Documents 1.2. Document Structure and Related Documents
The entire document is organized as follows: The entire document is organized as follows:
o Section 2 presents an overview of the protocol design. o Section 2 presents an overview of the protocol design.
o Sections 3 to 10 define a general framework of the Mutual o Sections 3 to 11 define a general framework of the Mutual
authentication protocol. This framework is independent of authentication protocol. This framework is independent of
specific cryptographic primitives. specific cryptographic primitives.
o Section 11 describes properties needed for cryptographic o Section 12 describes properties needed for cryptographic
algorithms used with this protocol framework, and defines a few algorithms used with this protocol framework, and defines a few
functions which will be shared among such cryptographic functions which will be shared among such cryptographic
algorithms. algorithms.
o The sections after that contain general normative and informative o The sections after that contain general normative and informative
information about the protocol. information about the protocol.
o The appendices contain some information that may help developers o The appendices contain some information that may help developers
to implement the protocol. to implement the protocol.
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| | | |
| <------ 401-KEX-S1 --- | | <------ 401-KEX-S1 --- |
| | | |
| --- req-VFY-C -------> | | --- req-VFY-C -------> |
| | | |
| <------- 200-VFY-S --- | | <------- 200-VFY-S --- |
| | | |
Figure 2: Several alternative flows on protocol Figure 2: Several alternative flows on protocol
For more details, see Sections 9 and 10. For more details, see Sections 10 and 11.
3. Message Syntax 3. Message Syntax
Throughout this specification, The syntax is denoted in the extended Throughout this specification, The syntax is denoted in the extended
augmented BNF syntax defined in [RFC7230] and [RFC5234]. The augmented BNF syntax defined in [RFC7230] and [RFC5234]. The
following elements are quoted from [RFC5234], [RFC7230] and following elements are quoted from [RFC5234], [RFC7230] and
[RFC7235]: DIGIT, ALPHA, SP, auth-scheme, quoted-string, auth-param, [RFC7235]: DIGIT, ALPHA, SP, auth-scheme, quoted-string, auth-param,
header-field, token, challenge, and credential. header-field, token, challenge, and credential.
The Mutual authentication protocol uses three headers: The Mutual authentication protocol uses three headers:
WWW-Authenticate (in responses with status code 401), Authorization WWW-Authenticate (in responses with status code 401), Authorization
(in requests), and Authentication-Info (in responses other than 401 (in requests), and Authentication-Info (in responses other than 401
status). These headers follow a common framework described in status). These headers follow a common framework described in
[RFC7235]. The detailed meanings for these headers are contained in [RFC7235] and [I-D.ietf-httpbis-auth-info]. The detailed meanings
Section 4. for these headers are contained in Section 4.
The framework in [RFC7235] defines the syntax for the headers The framework in [RFC7235] defines the syntax for the headers
WWW-Authenticate and Authorization as the syntax elements "challenge" WWW-Authenticate and Authorization as the syntax elements "challenge"
and "credentials", respectively. The "auth-scheme" contained in and "credentials", respectively. The "auth-scheme" contained in
those headers MUST be "Mutual" throughout this protocol those headers MUST be "Mutual" throughout this protocol
specification. The syntax for "challenge" and "credentials" to be specification. The syntax for "challenge" and "credentials" to be
used with the "Mutual" auth-scheme SHALL be name-value pairs (#auth- used with the "Mutual" auth-scheme SHALL be name-value pairs (#auth-
param), not the "b64token" defined in [RFC7235]. param), not the "b64token" defined in [RFC7235].
The Authentication-Info: header used in this protocol SHALL contain The Authentication-Info: header used in this protocol SHALL follow
the value in same syntax as those the "WWW-Authenticate" header, i.e. the syntax defined in [I-D.ietf-httpbis-auth-info].
the "challenge" syntax element.
In HTTP, the WWW-Authenticate header may contain more than one In HTTP, the WWW-Authenticate header may contain more than one
challenges. Client implementations SHOULD be aware of and be capable challenges. Client implementations SHOULD be aware of and be capable
of handle those cases correctly. of handle those cases correctly.
3.1. Values 3.1. Non-ASCII extended header parameters
All of parameters contained in the above three headers, except the
"realm" field, MAY be extended to ISO 10646-1 values using the
framework described in [RFC5987]. All servers and clients MUST be
capable of receiving and sending values encoded in [RFC5987] syntax.
If a value to be sent contains only ASCII characters, the field MUST
be sent in clear using plain RFC 7235 syntax. The syntax extended by
RFC 5987 MUST NOT be used in this case.
If a value (except the "realm" header) contains one or more non-ASCII
characters, the parameter SHOULD be sent using the syntax defined in
Section 3.2 of [RFC5987] as "ext-parameter". Such parameter MUST
have charset value of "UTF-8", and the language value MUST always be
omitted (have an empty value). The same parameter MUST NOT be sent
twice or more, those in both plain- and extended-syntax.
For example, a parameter "user" with value "Renee or France" SHOULD
be sent as < user="Renee of France" >. If the value is "Ren<e
acute>e of France", it SHOULD be sent as < user*=UTF-
8''Ren%C3%89e%20of%20France > instead.
[RFC7235] requires realm parameter to be exist as its plain form (not
as extended "realm*" parameter), so RFC 5987 syntax MUST NOT be used
for this parameter.
3.2. Values
The parameter values contained in challenge/credentials MUST be The parameter values contained in challenge/credentials MUST be
parsed strictly conforming to the HTTP semantics (especially un- parsed strictly conforming to the HTTP semantics (especially un-
quoting of the string parameter values). In this protocol, those quoting of the string parameter values). In this protocol, those
values are further categorized into the following value types: tokens values are further categorized into the following value types: tokens
(bare-token and extensive-token), string, integer, hex-fixed-number, (bare-token and extensive-token), string, integer, hex-fixed-number,
and base64-fixed-number. and base64-fixed-number.
For clarity, implementations are RECOMMENDED to use the canonical For clarity, implementations are RECOMMENDED to use the canonical
representations specified in the following subsections for sending representations specified in the following subsections for sending
values. Recipients SHOULD accept both quoted and unquoted values. Recipients SHOULD accept both quoted and unquoted
representations interchangeably as specified in HTTP. representations interchangeably as specified in HTTP.
3.1.1. Tokens 3.2.1. Tokens
For sustaining both security and extensibility at the same time, this For sustaining both security and extensibility at the same time, this
protocol defines a stricter sub-syntax for the "token" to be used. protocol defines a stricter sub-syntax for the "token" to be used.
The extensive-token values SHOULD follow the following syntax (after The extensive-token values SHOULD follow the following syntax (after
HTTP value parsing): HTTP value parsing):
bare-token = 1*(DIGIT / ALPHA / "-" / "_") bare-token = 1*(DIGIT / ALPHA / "-" / "_")
extension-token = "-" bare-token 1*("." bare-token) extension-token = "-" bare-token 1*("." bare-token)
extensive-token = bare-token / extension-token extensive-token = bare-token / extension-token
Figure 3: BNF syntax for token values Figure 3: BNF syntax for token values
The tokens (bare-token and extension-token) are case insensitive; The tokens (bare-token and extension-token) are case insensitive;
Senders SHOULD send these in lower-case, and receivers MUST accept Senders SHOULD send these in lower-case, and receivers MUST accept
both upper- and lower-cases. When tokens are used as (partial) both upper- and lower-cases. When tokens are used as (partial)
inputs to any hash or other mathematical functions, it MUST always be inputs to any hash or other mathematical functions, it MUST always be
used in lower-case. used in lower-case.
Extensive-tokens are used in this protocol where the set of Extensive-tokens are used in this protocol where the set of
acceptable tokens may include non-standard extensions. Any non- acceptable tokens may include non-standard extensions. Any non-
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with format "-<bare-token>.<domain-name>", where <domain-name> is a with format "-<bare-token>.<domain-name>", where <domain-name> is a
validly registered (sub-)domain name on the Internet owned by the validly registered (sub-)domain name on the Internet owned by the
party who defines the extensions. party who defines the extensions.
Bare-tokens and extensive-tokens are also used for parameter names Bare-tokens and extensive-tokens are also used for parameter names
(of course in the unquoted form). Requirements for using the (of course in the unquoted form). Requirements for using the
extension-token for the parameter names are the same as the above. extension-token for the parameter names are the same as the above.
The canonical format for bare-tokens and tokens are unquoted tokens. The canonical format for bare-tokens and tokens are unquoted tokens.
3.1.2. Strings 3.2.2. Strings
All character strings MUST be encoded to octet strings using the All character strings MUST be encoded to octet strings using the
UTF-8 encoding [RFC3629] for the ISO 10646-1 character set UTF-8 encoding [RFC3629] for the ISO 10646-1 character set
[ISO.10646-1.1993]. Such strings MUST NOT contain any leading BOM [ISO.10646-1.1993]. Such strings MUST NOT contain any leading BOM
characters (ZERO WIDTH NO-BREAK SPACE, U+FEFF or EF BB BF). Both characters (ZERO WIDTH NO-BREAK SPACE, U+FEFF or EF BB BF). Both
peers are RECOMMENDED to reject any invalid UTF-8 sequences that peers are RECOMMENDED to reject any invalid UTF-8 sequences that
might cause decoding ambiguities (e.g., containing <"> in the second might cause decoding ambiguities (e.g., containing <"> in the second
or later bytes of the UTF-8 encoded characters). or later bytes of the UTF-8 encoded characters).
If strings are representing a domain name or URI that contains non- If strings are representing a domain name or URI that contains non-
ASCII characters, the host parts SHOULD be encoded as it is used in ASCII characters, the host parts SHOULD be encoded as it is used in
the HTTP protocol layer (e.g. in a Host: header); under current the HTTP protocol layer (e.g. in a Host: header); under current
standards it will be the one defined in [RFC5890]. It SHOULD use standards it will be the one defined in [RFC5890]. It SHOULD use
lower-case ASCII characters. lower-case ASCII characters.
The canonical format for strings are quoted-string (as it may contain The canonical format for strings are quoted-string (as it may contain
equal signs, plus signs and slashes). equal signs, plus signs and slashes), unless the parameter containing
the string value will use extended syntax defined in [RFC5987].
([RFC5987] extended parameter will have unquoted encoded value, as
defined there.)
3.1.3. Numbers 3.2.3. Numbers
The following syntax definitions gives a syntax for number-type The following syntax definitions gives a syntax for number-type
values: values:
integer = "0" / (%x31-39 *DIGIT) ; no leading zeros integer = "0" / (%x31-39 *DIGIT) ; no leading zeros
hex-fixed-number = 1*(2(DIGIT / %x41-46 / %x61-66)) hex-fixed-number = 1*(2(DIGIT / %x41-46 / %x61-66))
base64-fixed-number = 1*( ALPHA / DIGIT / "+" / "/" ) 0*2"=" base64-fixed-number = 1*( ALPHA / DIGIT / "+" / "/" ) 0*2"="
Figure 4: BNF syntax for number types Figure 4: BNF syntax for number types
skipping to change at page 13, line 50 skipping to change at page 14, line 29
The canonical format for integer and hex-fixed-number are unquoted The canonical format for integer and hex-fixed-number are unquoted
tokens, and that for base64-fixed-number is quoted-string. tokens, and that for base64-fixed-number is quoted-string.
4. Messages 4. Messages
In this section we define the seven kinds of messages used in the In this section we define the seven kinds of messages used in the
authentication protocol along with the formats and requirements of authentication protocol along with the formats and requirements of
the headers for each message. the headers for each message.
To determine which message are expected to be sent, see Sections 9 To determine which message are expected to be sent, see Sections 10
and 10. and 11.
In the descriptions below, the type of allowable values for each In the descriptions below, the type of allowable values for each
header parameter is shown in parenthesis after each parameter name. header parameter is shown in parenthesis after each parameter name.
The "algorithm-determined" type means that the acceptable value for The "algorithm-determined" type means that the acceptable value for
the parameter is one of the types defined in Section 3, and is the parameter is one of the types defined in Section 3, and is
determined by the value of the "algorithm" parameter. The parameters determined by the value of the "algorithm" parameter. The parameters
marked "mandatory" SHALL be contained in the message. The parameters marked "mandatory" SHALL be contained in the message. The parameters
marked "non-mandatory" MAY either be contained or omitted in the marked "non-mandatory" MAY either be contained or omitted in the
message. Each parameter SHALL appear in each headers exactly once at message. Each parameter SHALL appear in each headers exactly once at
most. most.
All credentials and challenges MAY contain any parameters not All credentials and challenges MAY contain any parameters not
explicitly specified in the following sections. Recipients who do explicitly specified in the following sections. Recipients who do
not understand such parameters MUST silently ignore those. However, not understand such parameters MUST silently ignore those. However,
all credentials and challenges MUST meet the following criteria: all credentials and challenges MUST meet the following criteria:
o For responses, the parameters "reason", any "ks*" (where * stands o For responses, the parameters "reason", any "ks#" (where # stands
for any decimal integers), and "vks" are mutually exclusive: any for any decimal integers), and "vks" are mutually exclusive: any
challenge MUST NOT contain two or more parameters among them. challenge MUST NOT contain two or more parameters among them.
They MUST NOT contain any "kc*" and "vkc" parameters. They MUST NOT contain any "kc#" and "vkc" parameters.
o For requests, the parameters "kc*" (where * stands for any decimal o For requests, the parameters "kc#" (where # stands for any decimal
integers), and "vkc" are mutually exclusive and any challenge integers), and "vkc" are mutually exclusive and any challenge
MUST NOT contain two or more parameters among them. They MUST NOT MUST NOT contain two or more parameters among them. They MUST NOT
contain any "ks*" and "vks" parameters. contain any "ks#" and "vks" parameters.
Every message in this section contains a "version" field, to detect Every message in this section contains a "version" field, to detect
future incompatible revisions of the protocol. Implementations of future incompatible revisions of the protocol. Implementations of
the protocol described in this specification MUST always send a token the protocol described in this specification MUST always send a token
"-wg-draft03", and recipients MUST reject messages which contain any "-wg-draft04", and recipients MUST reject messages which contain any
other value as a version, unless another specification defines a other value as a version, unless another specification defines a
behavior for that version. [[Editorial Note: This token is updated behavior for that version. [[Editorial Note: This token is updated
on every draft revisions which will affect the wire protocol. It on every draft revisions which will affect the wire protocol. It
will (shall) be updated to "1" in the final published RFC.]] will (shall) be updated to "1" in the final published RFC.]]
4.1. 401-INIT and 401-STALE 4.1. 401-INIT and 401-STALE
Every 401-INIT or 401-STALE message SHALL be a valid HTTP 401-status Every 401-INIT or 401-STALE message SHALL be a valid HTTP 401-status
(Authentication Required) message containing one (and only one: (Authentication Required) message containing one (and only one:
hereafter not explicitly noticed) "WWW-Authenticate" header hereafter not explicitly noticed) "WWW-Authenticate" header
containing a "reason" parameter in the challenge. The challenge containing a "reason" parameter in the challenge. The challenge
SHALL contain all of the parameters marked "mandatory" below, and MAY SHALL contain all of the parameters marked "mandatory" below, and MAY
contain those marked "non-mandatory". contain those marked "non-mandatory".
version: (mandatory extensive-token) should be the token "-wg- version: (mandatory extensive-token) should be the token "-wg-
draft03". draft04".
algorithm: (mandatory extensive-token) specifies the algorithm: (mandatory extensive-token) specifies the
authentication algorithm to be used. The value MUST authentication algorithm to be used. The value MUST
be one of the tokens specified in be one of the tokens specified in
[I-D.ietf-httpauth-mutual-algo] or other supplemental [I-D.ietf-httpauth-mutual-algo] or other supplemental
specification documentation. specification documentation.
validation: (mandatory extensive-token) specifies the method of validation: (mandatory extensive-token) specifies the method of
host validation. The value MUST be one of the tokens host validation. The value MUST be one of the tokens
described in Section 7, or the tokens specified in described in Section 7, or the tokens specified in
other supplemental specification documentation. other supplemental specification documentation.
auth-domain: (non-mandatory string) specifies the authentication auth-domain: (non-mandatory string) specifies the authentication
domain, the set of hosts for which the authentication domain, the set of hosts for which the authentication
credentials are valid. It MUST be one of the strings credentials are valid. It MUST be one of the strings
described in Section 5. If the value is omitted, it described in Section 5. If the value is omitted, it
is assumed to be the "single-server" type domain in is assumed to be the "single-server" type domain in
Section 5. Section 5.
realm: (mandatory string) is a UTF-8 encoded string realm: (mandatory string) is a string representing the name
representing the name of the authentication realm of the authentication realm inside the authentication
inside the authentication domain. As specified in domain. As specified in [RFC7235], this value MUST
[RFC7235], this value MUST always be sent in the always be sent in the quoted-string form, and an
quoted-string form.
[RFC5987] encoding MUST NOT be used.
The realm value sent from the server SHOULD be an
ASCII string. Clients MAY treat any non-ASCII value
received in this field as one of a binary blob, an
NFC-normalized UTF-8 string, or an error.
pwd-hash: (non-mandatory extensive-token) specifies the hash pwd-hash: (non-mandatory extensive-token) specifies the hash
algorithm (hereafter referred to by ph) used for algorithm (hereafter referred to by ph) used for
additionally hashing the password. The valid tokens additionally hashing the password. The valid tokens
are are
* none: ph(p) = p * none: ph(p) = p
* md5: ph(p) = MD5(p) * md5: ph(p) = MD5(p)
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4.2. req-KEX-C1 4.2. req-KEX-C1
Every req-KEX-C1 message SHALL be a valid HTTP request message Every req-KEX-C1 message SHALL be a valid HTTP request message
containing an "Authorization" header with a credential containing a containing an "Authorization" header with a credential containing a
"kc1" parameter. "kc1" parameter.
The credential SHALL contain the parameters with the following names: The credential SHALL contain the parameters with the following names:
version: (mandatory, extensive-token) should be the token "-wg- version: (mandatory, extensive-token) should be the token "-wg-
draft03". draft04".
algorithm, validation, auth-domain, realm: MUST be the same value as algorithm, validation, auth-domain, realm: MUST be the same value as
it is when received from the server. it is when received from the server.
user: (mandatory, string) is the UTF-8 encoded name of the user: (mandatory, string) is the UTF-8 encoded name of the
user. If this name comes from a user input, client user. The string SHOULD be prepared according to the
software SHOULD prepare the string using HTTPAUTHprep method presented in Section 9.
[I-D.oiwa-precis-httpauthprep] before encoding it to
UTF-8. [[Editorial: merger with new SASLprep is being
considered and discussed in precis WG. Replace the
reference once it is done.]]
kc1: (mandatory, algorithm-determined) is the client-side kc1: (mandatory, algorithm-determined) is the client-side
key exchange value K_c1, which is specified by the key exchange value K_c1, which is specified by the
algorithm that is used. algorithm that is used.
4.3. 401-KEX-S1 4.3. 401-KEX-S1
Every 401-KEX-S1 message SHALL be a valid HTTP 401-status Every 401-KEX-S1 message SHALL be a valid HTTP 401-status
(Authentication Required) response message containing a (Authentication Required) response message containing a
"WWW-Authenticate" header with a challenge containing a "ks1" "WWW-Authenticate" header with a challenge containing a "ks1"
parameter. parameter.
The challenge SHALL contain the parameters with the following names: The challenge SHALL contain the parameters with the following names:
version: (mandatory, extensive-token) should be the token "-wg- version: (mandatory, extensive-token) should be the token "-wg-
draft03". draft04".
algorithm, validation, auth-domain, realm: MUST be the same value as algorithm, validation, auth-domain, realm: MUST be the same value as
it is when received from the client. it is when received from the client.
sid: (mandatory, hex-fixed-number) MUST be a session sid: (mandatory, hex-fixed-number) MUST be a session
identifier, which is a random integer. The sid SHOULD identifier, which is a random integer. The sid SHOULD
have uniqueness of at least 80 bits or the square of have uniqueness of at least 80 bits or the square of
the maximal estimated transactions concurrently the maximal estimated transactions concurrently
available in the session table, whichever is larger. available in the session table, whichever is larger.
See Section 6 for more details. See Section 6 for more details.
skipping to change at page 19, line 6 skipping to change at page 19, line 32
4.4. req-VFY-C 4.4. req-VFY-C
Every req-VFY-C message SHALL be a valid HTTP request message Every req-VFY-C message SHALL be a valid HTTP request message
containing an "Authorization" header with a credential containing a containing an "Authorization" header with a credential containing a
"vkc" parameter. "vkc" parameter.
The parameters contained in the header are as follows: The parameters contained in the header are as follows:
version: (mandatory, extensive-token) should be the token "-wg- version: (mandatory, extensive-token) should be the token "-wg-
draft03". draft04".
algorithm, validation, auth-domain, realm: MUST be the same value as algorithm, validation, auth-domain, realm: MUST be the same value as
it is when received from the server for the session. it is when received from the server for the session.
sid: (mandatory, hex-fixed-number) MUST be one of the sid sid: (mandatory, hex-fixed-number) MUST be one of the sid
values that was received from the server for the same values that was received from the server for the same
authentication realm. authentication realm.
nc: (mandatory, integer) is a nonce value that is unique nc: (mandatory, integer) is a nonce value that is unique
among the requests sharing the same sid. The values among the requests sharing the same sid. The values
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4.5. 200-VFY-S 4.5. 200-VFY-S
Every 200-VFY-S message SHALL be a valid HTTP message that is not of Every 200-VFY-S message SHALL be a valid HTTP message that is not of
the 401 (Authentication Required) status, containing an the 401 (Authentication Required) status, containing an
"Authentication-Info" header with a "vks" parameter. "Authentication-Info" header with a "vks" parameter.
The parameters contained in the header are as follows: The parameters contained in the header are as follows:
version: (mandatory, extensive-token) should be the token "-wg- version: (mandatory, extensive-token) should be the token "-wg-
draft03". draft04".
sid: (mandatory, hex-fixed-number) MUST be the value sid: (mandatory, hex-fixed-number) MUST be the value
received from the client. received from the client.
vks: (mandatory, algorithm-determined) is the server-side vks: (mandatory, algorithm-determined) is the server-side
authentication verification value VK_s, which is authentication verification value VK_s, which is
specified by the algorithm. specified by the algorithm.
The header MUST be sent before the content body: it MUST NOT be sent The header MUST be sent before the content body: it MUST NOT be sent
in the trailer of a chunked-encoded response. If a "100 Continue" in the trailer of a chunked-encoded response. If a "100 Continue"
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5.1. Resolving Ambiguities 5.1. Resolving Ambiguities
In the above definitions of authentication domains, several domains In the above definitions of authentication domains, several domains
will overlap each other. If a client has already been authenticated will overlap each other. If a client has already been authenticated
to several realms applicable to the same server, the client may have to several realms applicable to the same server, the client may have
a multiple list of the "path" parameters received with the a multiple list of the "path" parameters received with the
"401-KEX-S1" message (see Section 4). If these path lists have any "401-KEX-S1" message (see Section 4). If these path lists have any
overlap, a single URI may belong to multiple possible candidate of overlap, a single URI may belong to multiple possible candidate of
realms to be authenticated to. In such cases, clients faces an realms to be authenticated to. In such cases, clients faces an
ambiguity on deciding which credentials to be sent for a new request ambiguity on deciding which credentials to be sent for a new request
(in steps 3 and 4 of the decision procedure presented in Section 9). (in steps 3 and 4 of the decision procedure presented in Section 10).
In such cases, clients MAY send requests which belongs to any of In such cases, clients MAY send requests which belongs to any of
these candidate realms freely, or it MAY simply send an these candidate realms freely, or it MAY simply send an
unauthenticated request and see for which realm the server request an unauthenticated request and see for which realm the server request an
authentication. Server operators are RECOMMENDED to provide authentication. Server operators are RECOMMENDED to provide
properly-configured "path" parameters (more precisely, disjoint path properly-configured "path" parameters (more precisely, disjoint path
sets for each realms) for clients so that such ambiguities will not sets for each realms) for clients so that such ambiguities will not
occur. occur.
The following procedure are one of the possible tactics for resolving The following procedure are one of the possible tactics for resolving
skipping to change at page 23, line 22 skipping to change at page 24, line 5
The last condition allows servers to reject any nonce values that are The last condition allows servers to reject any nonce values that are
"significantly" smaller than the "current" value (defined by the "significantly" smaller than the "current" value (defined by the
value of nc-window) of the nonce used in the session involved. In value of nc-window) of the nonce used in the session involved. In
other words, servers MAY treat such nonces as "already received". other words, servers MAY treat such nonces as "already received".
This restriction enables servers to implement duplicated nonce This restriction enables servers to implement duplicated nonce
detection in a constant amount of memory (for each session). detection in a constant amount of memory (for each session).
Servers MUST check for duplication of the received nonces, and if any Servers MUST check for duplication of the received nonces, and if any
duplication is detected, the server MUST discard the session and duplication is detected, the server MUST discard the session and
respond with a 401-STALE message, as outlined in Section 10. The respond with a 401-STALE message, as outlined in Section 11. The
server MAY also reject other invalid nonce values (such as ones above server MAY also reject other invalid nonce values (such as ones above
the nc-max limit) by sending a 401-STALE message. the nc-max limit) by sending a 401-STALE message.
For example, assume the nc-window value of the current session is 32, For example, assume the nc-window value of the current session is 32,
nc-max is 100, and that the client has already used the following nc-max is 100, and that the client has already used the following
nonce values: {1-20, 22, 24, 30-38, 45-60, 63-72}. Then the nonce nonce values: {1-20, 22, 24, 30-38, 45-60, 63-72}. Then the nonce
values that can be used for next request is one of the following set: values that can be used for next request is one of the following set:
{41-44, 61-62, 73-100}. The values {0, 21, 23, 25-29, 39-40} MAY be {41-44, 61-62, 73-100}. The values {0, 21, 23, 25-29, 39-40} MAY be
rejected by the server because they are not above the current "window rejected by the server because they are not above the current "window
limit" (40 = 72 - 32). limit" (40 = 72 - 32).
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This specification also proposes (however, not mandates) default This specification also proposes (however, not mandates) default
"auth-style" to be "non-modal". Web applications SHOULD however "auth-style" to be "non-modal". Web applications SHOULD however
consider the security impacts of the behaviors of clients that do not consider the security impacts of the behaviors of clients that do not
support these headers. support these headers.
Authentication-initializing messages with the Authentication-initializing messages with the
Optional-WWW-Authenticate header are used only where 401-INIT Optional-WWW-Authenticate header are used only where 401-INIT
response is valid. It will not replace other 401-type messages such response is valid. It will not replace other 401-type messages such
as 401-STALE and 401-KEX-S1. as 401-STALE and 401-KEX-S1.
9. Decision Procedure for Clients 9. String Preparation
9.1. General Principles and Requirements It is important for interoperability that user-names and passwords
used in this protocol is binary-comparable regardless of the user's
input methods and/or environments. To ensure this, the following
preparation SHOULD be performed:
o User-names received from users SHOULD be prepared using the
"UsernameCasePreserved" profile defined in Section 3.3 of
[I-D.ietf-precis-saslprepbis].
o Passwords received from users SHOULD be prepared using the
"OpaqueString" profile defined in Section 4.2 of
[I-D.ietf-precis-saslprepbis].
In both cases, it is the sender's duty to correctly preparing the
character strings. If any non-normalized character string is
received from the other peer of the communication, recipients MAY
either use it as a bare UTF-8 string without any preparation, perform
any appropriate preparations (which may cause authentication
failure), or reject any ill-prepared inputs from the sender and
respond as a communication error.
Server applications SHOULD also prepare user-names and passwords
accordingly upon registration of user credentials.
In addition, binary-based "interfaces" of implementations MAY require
and assume that the string is already prepared accordingly; in
detail, when a string is already stored as an binary Unicode string
form, implementations MAY omit preparation and Unicode normalization
(performs UTF-8 encoding only) before using it. When a string is
already stored as an octet blob, implementations MAY send it as it
is.
10. Decision Procedure for Clients
10.1. General Principles and Requirements
To securely implement the protocol, the user client must be careful To securely implement the protocol, the user client must be careful
about accepting the authenticated responses from the server. This about accepting the authenticated responses from the server. This
also holds true for the reception of "normal responses" (responses also holds true for the reception of "normal responses" (responses
which do not contain Mutual-related headers) from HTTP servers. which do not contain Mutual-related headers) from HTTP servers.
As usual in the HTTP authentication, a single user-level request may As usual in the HTTP authentication, a single user-level request may
result in exchange of two-or-more HTTP requests and responses in result in exchange of two-or-more HTTP requests and responses in
sequence. The following care MUST be taken by the all clients sequence. The following care MUST be taken by the all clients
implementing this protocol: implementing this protocol:
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it is still RECOMMENDED, as it may possibly be forged by intermediate it is still RECOMMENDED, as it may possibly be forged by intermediate
attackers,) and the client will be in the "UNAUTHENTICATED" status attackers,) and the client will be in the "UNAUTHENTICATED" status
then. then.
If a request is a sub-request for a resource included in another If a request is a sub-request for a resource included in another
resources (e.g., embedded images, style sheets, frames etc.), clients resources (e.g., embedded images, style sheets, frames etc.), clients
MAY treat an AUTH-REQUESTED status as the same as UNAUTHENTICATED MAY treat an AUTH-REQUESTED status as the same as UNAUTHENTICATED
status. In other words, the client MAY ignore server's request to status. In other words, the client MAY ignore server's request to
start authentication with new credentials via sub-requests. start authentication with new credentials via sub-requests.
9.2. State machine for the client-side 10.2. State machine for the client-side
The following state machine describes the possible request-response The following state machine describes the possible request-response
sequences derived from the above general rules. If implementors are sequences derived from the above general rules. If implementors are
not quite sure on the security consequences of the above rules, it is not quite sure on the security consequences of the above rules, it is
strongly RECOMMENDED to follow the decision procedure below. In strongly RECOMMENDED to follow the decision procedure below. In
particular, clients SHOULD NOT accept "normal responses" unless particular, clients SHOULD NOT accept "normal responses" unless
explicitly allowed in the rules. The labels on the steps are for explicitly allowed in the rules. The labels on the steps are for
informational purposes only. Action entries within each step are informational purposes only. Action entries within each step are
checked in top-to-bottom order, and the first clause satisfied SHOULD checked in top-to-bottom order, and the first clause satisfied SHOULD
be taken. be taken.
skipping to change at page 33, line 5 skipping to change at page 34, line 5
| |200-VFY-S | 200-VFY-S| ^ | |200-VFY-S | 200-VFY-S| ^
|normal | |200-VFY-S / | |normal | |200-VFY-S / |
|response | v / ================== |response | v / ==================
v \ -(14)--------- / USER/PASS INPUTTED v \ -(14)--------- / USER/PASS INPUTTED
-(11)------------ ------->( AUTH-SUCCEED )<-- ================== -(11)------------ ------->( AUTH-SUCCEED )<-- ==================
( UNAUTHENTICATED ) -------------- ( UNAUTHENTICATED ) --------------
----------------- -----------------
Figure 5: State diagram for clients Figure 5: State diagram for clients
10. Decision Procedure for Servers 11. Decision Procedure for Servers
Each server SHOULD have a table of session states. This table need Each server SHOULD have a table of session states. This table need
not be persistent over a long term; it MAY be cleared upon server not be persistent over a long term; it MAY be cleared upon server
restart, reboot, or others. Each entry in the table SHOULD contain restart, reboot, or others. Each entry in the table SHOULD contain
at least the following information: at least the following information:
o The session identifier, the value of the sid parameter. o The session identifier, the value of the sid parameter.
o The algorithm used. o The algorithm used.
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401-INIT messages marked with the asterisks can not be replaced with 401-INIT messages marked with the asterisks can not be replaced with
a successful responses with an Optional-WWW-Authenticate header. a successful responses with an Optional-WWW-Authenticate header.
Every other 401-INIT can be a response with an Every other 401-INIT can be a response with an
Optional-WWW-Authenticate. Optional-WWW-Authenticate.
Note 2: the server SHOULD NOT send a 401-INIT response in this case, Note 2: the server SHOULD NOT send a 401-INIT response in this case,
because it will leak the information to the client that the specified because it will leak the information to the client that the specified
user will not be accepted. Instead, postpone it to the response for user will not be accepted. Instead, postpone it to the response for
the next req-VFY-C request. the next req-VFY-C request.
11. Authentication Algorithms 12. Authentication Algorithms
Cryptographic authentication algorithms which are used with this Cryptographic authentication algorithms which are used with this
protocol will be defined separately. The algorithm definition MUST protocol will be defined separately. The algorithm definition MUST
at least provide a definitions for the following functions: at least provide a definitions for the following functions:
o The server-side authentication credential J, derived from user- o The server-side authentication credential J, derived from user-
side authentication credential pi. side authentication credential pi.
o Key exchange values K_c1, K_s1 (exchanged on wire) and S_c1, S_s1 o Key exchange values K_c1, K_s1 (exchanged on wire) and S_c1, S_s1
(kept secret in each peer). (kept secret in each peer).
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cryptographically strong shared secret value z, equivalently strong cryptographically strong shared secret value z, equivalently strong
to or stronger than the hash function H. If any passwords (or pass- to or stronger than the hash function H. If any passwords (or pass-
phrases or any equivalents, i.e. weak secrets) are involved, these phrases or any equivalents, i.e. weak secrets) are involved, these
SHOULD NOT be guessable from any data transmitted in the protocol, SHOULD NOT be guessable from any data transmitted in the protocol,
even if an attacker (either an eavesdropper or an active server) even if an attacker (either an eavesdropper or an active server)
knows the possible thoroughly-searchable candidate list of the knows the possible thoroughly-searchable candidate list of the
passwords. Furthermore, if possible, the function for deriving passwords. Furthermore, if possible, the function for deriving
server-side authentication credential J is RECOMMENDED to be one-way server-side authentication credential J is RECOMMENDED to be one-way
so that pi should not be easily computed from J(pi). so that pi should not be easily computed from J(pi).
11.1. Support Functions and Notations 12.1. Support Functions and Notations
In this section we define several support functions and notations to In this section we define several support functions and notations to
be shared by several algorithm definitions: be shared by several algorithm definitions:
The integers in the specification are in decimal, or in hexadecimal The integers in the specification are in decimal, or in hexadecimal
when prefixed with "0x". when prefixed with "0x".
The function octet(c) generates a single octet string whose code The function octet(c) generates a single octet string whose code
value is equal to c. The operator |, when applied to octet strings, value is equal to c. The operator |, when applied to octet strings,
denotes the concatenation of two operands. denotes the concatenation of two operands.
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VS([10000 "a"s]) = "\316\020aaaaa..." (10002 octets) VS([10000 "a"s]) = "\316\020aaaaa..." (10002 octets)
(Note: Unlike the colon-separated notion used in the Basic/Digest (Note: Unlike the colon-separated notion used in the Basic/Digest
HTTP authentication scheme, the string generated by a concatenation HTTP authentication scheme, the string generated by a concatenation
of the VS-encoded strings will be unique, regardless of the of the VS-encoded strings will be unique, regardless of the
characters included in the strings to be encoded.) characters included in the strings to be encoded.)
The function OCTETS converts an integer into the corresponding radix- The function OCTETS converts an integer into the corresponding radix-
256 big-endian octet string having its natural length: See 256 big-endian octet string having its natural length: See
Section 3.1.3 for the definition of "natural length". Section 3.2.3 for the definition of "natural length".
The function INT converts an octet string into a natural number, The function INT converts an octet string into a natural number,
where the input string is treated as a radix-256 big-endian notation. where the input string is treated as a radix-256 big-endian notation.
The identity INT(OCTETS(n)) = n always holds for any natural number The identity INT(OCTETS(n)) = n always holds for any natural number
n. n.
11.2. Default Functions for Algorithms 12.2. Default Functions for Algorithms
The functions defined in this section are common default functions The functions defined in this section are common default functions
among authentication algorithms. among authentication algorithms.
The client-side password-based (credential) pi used by this The client-side password-based (credential) pi used by this
authentication is a natural number derived in the following manner: authentication is a natural number derived in the following manner:
pi = INT(PBKDF2(HMAC_H, ph(password), VS(algorithm) | VS(auth-domain) pi = INT(PBKDF2(HMAC_H, ph(password), VS(algorithm) | VS(auth-domain)
| VS(realm) | VS(username), nIterPi, hSize / 8)), | VS(realm) | VS(username), nIterPi, hSize / 8)),
where where
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o HMAC_H is the HMAC function, defined in [RFC2104], composed from o HMAC_H is the HMAC function, defined in [RFC2104], composed from
the hash function H, and the hash function H, and
o hSize is the output size of hash H, counted in bits. o hSize is the output size of hash H, counted in bits.
The values of algorithm, realm, and auth-domain are taken from the The values of algorithm, realm, and auth-domain are taken from the
values contained in the 401-INIT message. The function ph is values contained in the 401-INIT message. The function ph is
determined by the value of the pwd-hash parameter given in a 401-INIT determined by the value of the pwd-hash parameter given in a 401-INIT
message. If the password comes from a user input, it SHOULD first be message. If the password comes from a user input, it SHOULD first be
prepared using [I-D.oiwa-precis-httpauthprep]. Then, the password prepared according to the method presented in Section 9. Then, the
SHALL be encoded as a UTF-8 string before passed to ph. password SHALL be encoded as a UTF-8 string before passed to ph.
The values VK_c and VK_s are derived by the following equation. The values VK_c and VK_s are derived by the following equation.
VK_c = INT(H(octet(4) | OCTETS(K_c1) | OCTETS(K_s1) | OCTETS(z) | VK_c = INT(H(octet(4) | OCTETS(K_c1) | OCTETS(K_s1) | OCTETS(z) |
VI(nc) | VS(vh))) VI(nc) | VS(vh)))
VK_s = INT(H(octet(3) | OCTETS(K_c1) | OCTETS(K_s1) | OCTETS(z) | VK_s = INT(H(octet(3) | OCTETS(K_c1) | OCTETS(K_s1) | OCTETS(z) |
VI(nc) | VS(vh))) VI(nc) | VS(vh)))
12. Application Channel Binding 13. Application Channel Binding
Applications and upper-layer communication protocols may need Applications and upper-layer communication protocols may need
authentication binding to the HTTP-layer authenticated user. Such authentication binding to the HTTP-layer authenticated user. Such
applications MAY use the following values as a standard shared applications MAY use the following values as a standard shared
secret. secret.
These values are parameterized with an optional octet string (t) These values are parameterized with an optional octet string (t)
which may be arbitrarily chosen by each applications or protocols. which may be arbitrarily chosen by each applications or protocols.
If there is no appropriate value to be specified, use a null string If there is no appropriate value to be specified, use a null string
for t. for t.
skipping to change at page 39, line 11 skipping to change at page 40, line 11
For applications requiring binding to a specific request (to ensure For applications requiring binding to a specific request (to ensure
that the payload data is generated for the exact HTTP request), the that the payload data is generated for the exact HTTP request), the
following value b_2 MAY be used. following value b_2 MAY be used.
b_2 = H(H(octet(7) | OCTETS(K_c1) | OCTETS(K_s1) | OCTETS(z) | VI(nc) b_2 = H(H(octet(7) | OCTETS(K_c1) | OCTETS(K_s1) | OCTETS(z) | VI(nc)
| VS(vh)) | VS(t)). | VS(vh)) | VS(t)).
Note: Channel bindings to lower-layer transports (TCP and TLS) are Note: Channel bindings to lower-layer transports (TCP and TLS) are
defined in Section 7. defined in Section 7.
13. Application for Proxy Authentication 14. Application for Proxy Authentication
The authentication scheme defined by the previous sections can be The authentication scheme defined by the previous sections can be
applied (with modifications) for proxy authentications. In such applied (with modifications) for proxy authentications. In such
cases, the following alterations MUST be applied: cases, the following alterations MUST be applied:
o The 407 status is to be sent and recognized for places where the o The 407 status is to be sent and recognized for places where the
401 status is used, 401 status is used,
o Proxy-Authenticate: header is to be used for places where WWW- o Proxy-Authenticate: header is to be used for places where WWW-
Authenticate: is used, Authenticate: is used,
skipping to change at page 39, line 46 skipping to change at page 40, line 46
o The omission of the path parameter of 401-KEX-S1 messages means o The omission of the path parameter of 401-KEX-S1 messages means
that the authentication realm will potentially cover all requests that the authentication realm will potentially cover all requests
processed by the proxy, processed by the proxy,
o The scheme, host name and the port of the proxy is used for host o The scheme, host name and the port of the proxy is used for host
validation tokens, and validation tokens, and
o Authentication extensions in [I-D.ietf-httpauth-extension] are not o Authentication extensions in [I-D.ietf-httpauth-extension] are not
applicable. applicable.
14. Methods to Extend This Protocol 15. Methods to Extend This Protocol
If a private extension to this protocol is implemented, it MUST use If a private extension to this protocol is implemented, it MUST use
the extension-tokens defined in Section 3 to avoid conflicts with the extension-tokens defined in Section 3 to avoid conflicts with
this protocol and other extensions. (standardized or being- this protocol and other extensions. (standardized or being-
standardizing extensions MAY use either bare-tokens or extension- standardizing extensions MAY use either bare-tokens or extension-
tokens.) tokens.)
Specifications defining authentication algorithms MAY use other Specifications defining authentication algorithms MAY use other
representations for the parameters "kc1", "ks1", "vkc", and "vks", representations for the parameters "kc1", "ks1", "vkc", and "vks",
replace those parameter names, and/or add parameters to the messages replace those parameter names, and/or add parameters to the messages
skipping to change at page 40, line 23 skipping to change at page 41, line 23
"vkc" or "vks" and followed by decimal natural numbers (e.g. kc2, "vkc" or "vks" and followed by decimal natural numbers (e.g. kc2,
ks0, vkc1, vks3 etc.) are reserved for this purpose. If those ks0, vkc1, vks3 etc.) are reserved for this purpose. If those
specifications use names other than those mentioned above, it is specifications use names other than those mentioned above, it is
RECOMMENDED to use extension-tokens to avoid any parameter name RECOMMENDED to use extension-tokens to avoid any parameter name
conflict with the future extension of this protocol. conflict with the future extension of this protocol.
Extension-tokens MAY be freely used for any non-standard, private, Extension-tokens MAY be freely used for any non-standard, private,
and/or experimental uses for those parameters provided that the and/or experimental uses for those parameters provided that the
domain part in the token is appropriately used. domain part in the token is appropriately used.
15. IANA Considerations 16. IANA Considerations
When bare-tokens are used for the authentication-algorithm, pwd-hash, When bare-tokens are used for the authentication-algorithm, pwd-hash,
and validation parameters MUST be allocated by IANA. To acquire and validation parameters MUST be allocated by IANA. To acquire
registered tokens, a specification for the use of such tokens MUST be registered tokens, a specification for the use of such tokens MUST be
available as an RFC, as outlined in [RFC5226]. available as an RFC, as outlined in [RFC5226].
Note: More formal declarations will be added in the future drafts to Note: More formal declarations will be added in the future drafts to
meet the RFC 5226 requirements. meet the RFC 5226 requirements.
16. Security Considerations 17. Security Considerations
16.1. Security Properties 17.1. Security Properties
o The protocol is secure against passive eavesdropping and replay o The protocol is secure against passive eavesdropping and replay
attacks. However, the protocol relies on transport security attacks. However, the protocol relies on transport security
including DNS integrity for data secrecy and integrity. HTTP/TLS including DNS integrity for data secrecy and integrity. HTTP/TLS
SHOULD be used where transport security is not assured and/or data SHOULD be used where transport security is not assured and/or data
confidentiality is important. confidentiality is important.
o When used with HTTP/TLS, if TLS server certificates are reliably o When used with HTTP/TLS, if TLS server certificates are reliably
verified, the protocol provides true protection against active verified, the protocol provides true protection against active
man-in-the-middle attacks. man-in-the-middle attacks.
o Even if the server certificate is not used or is unreliable, the o Even if the server certificate is not used or is unreliable, the
protocol provides protection against active man-in-the-middle protocol provides protection against active man-in-the-middle
attacks for each HTTP request/response pair. However, in such attacks for each HTTP request/response pair. However, in such
cases, JavaScript or similar scripting facilities can be used to cases, JavaScript or similar scripting facilities can be used to
affect the Mutually-authenticated contents from other contents not affect the Mutually-authenticated contents from other contents not
protected by this authentication mechanism. This is the reason protected by this authentication mechanism. This is the reason
why this protocol requires that valid TLS server certificates MUST why this protocol requires that valid TLS server certificates MUST
be presented (Section 7). be presented (Section 7).
16.2. Denial-of-service Attacks to Servers 17.2. Denial-of-service Attacks to Servers
The protocol requires a server-side table of active sessions, which The protocol requires a server-side table of active sessions, which
may become a critical point of the server resource consumptions. For may become a critical point of the server resource consumptions. For
proper operation, the protocol requires that at least one key proper operation, the protocol requires that at least one key
verification request is processed for each session identifier. After verification request is processed for each session identifier. After
that, servers MAY discard sessions internally at any time, without that, servers MAY discard sessions internally at any time, without
causing any operational problems to clients. Clients will silently causing any operational problems to clients. Clients will silently
reestablishes a new session then. reestablishes a new session then.
However, if a malicious client sends too many requests of key However, if a malicious client sends too many requests of key
skipping to change at page 41, line 39 skipping to change at page 42, line 39
kind of negotiations or states, including Digest authentication kind of negotiations or states, including Digest authentication
method and most Cookie-based authentication implementations. method and most Cookie-based authentication implementations.
However, regarding the resource consumption, a situation of the However, regarding the resource consumption, a situation of the
mutual authentication method is a slightly better than the Digest, mutual authentication method is a slightly better than the Digest,
because HTTP requests without any kind of authentication requests because HTTP requests without any kind of authentication requests
will not generate any kind of sessions. Session identifiers are only will not generate any kind of sessions. Session identifiers are only
generated after a client starts a key negotiation. It means that generated after a client starts a key negotiation. It means that
simple clients such as web crawlers will not accidentally consume simple clients such as web crawlers will not accidentally consume
server-side resources for session managements. server-side resources for session managements.
16.2.1. On-line Active Password Attacks 17.2.1. On-line Active Password Attacks
Although the protocol provides very strong protection against off- Although the protocol provides very strong protection against off-
line dictionary attacks from eavesdropped traffics, the protocol, by line dictionary attacks from eavesdropped traffics, the protocol, by
its nature, can not prevent an active password attacks which the its nature, can not prevent an active password attacks which the
attackers sends so many authentication trial requests for every attackers sends so many authentication trial requests for every
possible passwords. possible passwords.
Possible countermeasures for preventing such attacks may be rate- Possible countermeasures for preventing such attacks may be rate-
limiting of the password authentication trials, statistics-based limiting of the password authentication trials, statistics-based
intrusion detection measures or similar protection schemes. If the intrusion detection measures or similar protection schemes. If the
server operators assume that the passwords of users are not strong server operators assume that the passwords of users are not strong
enough, it may be desirable to introduce such ad-hoc countermeasures. enough, it may be desirable to introduce such ad-hoc countermeasures.
16.3. Communicating the status of mutual authentication with users 17.3. Communicating the status of mutual authentication with users
This protocol is designed for two goals. The first goal is just This protocol is designed for two goals. The first goal is just
providing a secure alternative for existing Basic and Digest providing a secure alternative for existing Basic and Digest
authentication. The second goal is to provide users a way to detect authentication. The second goal is to provide users a way to detect
forged rogue servers imitating user's registered account on server- forged rogue servers imitating user's registered account on server-
side, commonly known as (a part or kind of) Phishing attacks. side, commonly known as (a part or kind of) Phishing attacks.
For this protocol to effectively work as some countermeasures to such For this protocol to effectively work as some countermeasures to such
attacks, it is very important that end users of clients will be attacks, it is very important that end users of clients will be
notified of the result of mutual authentication performed by this notified of the result of mutual authentication performed by this
protocol, especially the three states "AUTH-SUCCEED", protocol, especially the three states "AUTH-SUCCEED",
"UNAUTHENTICATED" and "AUTH-REQUIRED" defined in Section 9. The "UNAUTHENTICATED" and "AUTH-REQUIRED" defined in Section 10. The
design of secure users' interfaces of the HTTP interactive clients design of secure users' interfaces of the HTTP interactive clients
are out of the scope of this document, but if possible, having some are out of the scope of this document, but if possible, having some
kind of UI indication for the three states above will be desirable kind of UI indication for the three states above will be desirable
for user's benefits on their security. for user's benefits on their security.
Of course, in such cases, the user interfaces for asking passwords Of course, in such cases, the user interfaces for asking passwords
for this authentication shall be clearly identifiable against for this authentication shall be clearly identifiable against
imitation by other insecure password input fields (such as forms). imitation by other insecure password input fields (such as forms).
If the passwords are known to malicious attackers outside of the If the passwords are known to malicious attackers outside of the
protocol, the protocol can not work as an effective security protocol, the protocol can not work as an effective security
measures. measures.
16.4. Implementation Considerations 17.4. Implementation Considerations
o To securely implement the protocol, the Authentication-Info o To securely implement the protocol, the Authentication-Info
headers in the 200-VFY-S messages MUST always be validated by the headers in the 200-VFY-S messages MUST always be validated by the
client. If the validation fails, the client MUST NOT process any client. If the validation fails, the client MUST NOT process any
content sent with the message, including other headers and the content sent with the message, including other headers and the
body part. Non-compliance to this requirement will allow phishing body part. Non-compliance to this requirement will allow phishing
attacks. attacks.
o For HTTP/TLS communications, when a web form is submitted from o For HTTP/TLS communications, when a web form is submitted from
Mutually-authenticated pages with the "tls-server-end-point" Mutually-authenticated pages with the "tls-server-end-point"
skipping to change at page 43, line 5 skipping to change at page 44, line 5
RECOMMENDED to be revalidated using a req-KEX-C1 message with an RECOMMENDED to be revalidated using a req-KEX-C1 message with an
"Expect: 100-continue" header. The same applies when the page is "Expect: 100-continue" header. The same applies when the page is
received with the "tls-unique" validation method, and when the TLS received with the "tls-unique" validation method, and when the TLS
session has expired. session has expired.
o For better protection against possible password database steal, o For better protection against possible password database steal,
Server-side storages of user passwords are better containing the Server-side storages of user passwords are better containing the
values encrypted by one-way function J(pi), instead of the real values encrypted by one-way function J(pi), instead of the real
passwords, those hashed by ph, or pi. passwords, those hashed by ph, or pi.
16.5. Usage Considerations 17.5. Usage Considerations
o The user-names inputted by a user may be sent automatically to any o The user-names inputted by a user may be sent automatically to any
servers sharing the same auth-domain. This means that when host- servers sharing the same auth-domain. This means that when host-
type auth-domain is used for authentication on an HTTPS site, and type auth-domain is used for authentication on an HTTPS site, and
when an HTTP server on the same host requests Mutual when an HTTP server on the same host requests Mutual
authentication within the same realm, the client will send the authentication within the same realm, the client will send the
user-name in a clear text. If user-names have to be kept secret user-name in a clear text. If user-names have to be kept secret
against eavesdropping, the server must use full-scheme-type auth- against eavesdropping, the server must use full-scheme-type auth-
domain parameter and HTTPS. Contrarily, passwords are not exposed domain parameter and HTTPS. Contrarily, passwords are not exposed
to eavesdroppers even on HTTP requests. to eavesdroppers even on HTTP requests.
skipping to change at page 43, line 31 skipping to change at page 44, line 31
passwords were not exposed to the public. Note that hashed passwords were not exposed to the public. Note that hashed
password databases for plain-text authentications are usually not password databases for plain-text authentications are usually not
considered secret. considered secret.
o If the server provides several ways for storing server-side o If the server provides several ways for storing server-side
password secrets into the password database, it is desirable for password secrets into the password database, it is desirable for
better security to store the values encrypted by using the one-way better security to store the values encrypted by using the one-way
function J(pi), instead of the real passwords, those hashed by ph, function J(pi), instead of the real passwords, those hashed by ph,
or pi. or pi.
17. Notice on Intellectual Properties 18. Notice on Intellectual Properties
The National Institute of Advanced Industrial Science and Technology The National Institute of Advanced Industrial Science and Technology
(AIST) and Yahoo! Japan, Inc. has jointly submitted a patent (AIST) and Yahoo! Japan, Inc. has jointly submitted a patent
application on the protocol proposed in this documentation to the application on the protocol proposed in this documentation to the
Patent Office of Japan. The patent is intended to be open to any Patent Office of Japan. The patent is intended to be open to any
implementors of this protocol and its variants under non-exclusive implementors of this protocol and its variants under non-exclusive
royalty-free manner. For the details of the patent application and royalty-free manner. For the details of the patent application and
its status, please contact the author of this document. its status, please contact the author of this document.
The elliptic-curve based authentication algorithms might involve The elliptic-curve based authentication algorithms might involve
several existing third-party patents. The authors of the document several existing third-party patents. The authors of the document
take no position regarding the validity or scope of such patents, and take no position regarding the validity or scope of such patents, and
other patents as well. other patents as well.
18. References 19. References
18.1. Normative References 19.1. Normative References
[I-D.ietf-httpauth-extension] [I-D.ietf-httpauth-extension]
Oiwa, Y., Watanabe, H., Takagi, H., Hayashi, T., and Y. Oiwa, Y., Watanabe, H., Takagi, H., Hayashi, T., and Y.
Ioku, "HTTP Authentication Extensions for Interactive Ioku, "HTTP Authentication Extensions for Interactive
Clients", draft-ietf-httpauth-extension-02 (work in Clients", draft-ietf-httpauth-extension-03 (work in
progress), August 2014. progress), February 2015.
[I-D.oiwa-precis-httpauthprep] [I-D.ietf-httpbis-auth-info]
Oiwa, Y., Nemoto, T., and B. Kihara, "HTTPAuthPrep: PRECIS Reschke, J., "The Hypertext Transfer Protocol (HTTP)
profile for HTTP Authentication", Authentication-Info and Proxy- Authentication-Info
draft-oiwa-precis-httpauthprep-00 (work in progress), Response Header Fields", draft-ietf-httpbis-auth-info-02
July 2013. (work in progress), February 2015.
[I-D.ietf-precis-saslprepbis]
Saint-Andre, P. and A. Melnikov, "Preparation,
Enforcement, and Comparison of Internationalized Strings
Representing Usernames and Passwords",
draft-ietf-precis-saslprepbis-13 (work in progress),
December 2014.
[RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
Hashing for Message Authentication", RFC 2104, Hashing for Message Authentication", RFC 2104,
February 1997. February 1997.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2898] Kaliski, B., "PKCS #5: Password-Based Cryptography [RFC2898] Kaliski, B., "PKCS #5: Password-Based Cryptography
Specification Version 2.0", RFC 2898, September 2000. Specification Version 2.0", RFC 2898, September 2000.
skipping to change at page 44, line 40 skipping to change at page 45, line 47
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, October 2006. Encodings", RFC 4648, October 2006.
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008. Specifications: ABNF", STD 68, RFC 5234, January 2008.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008. (TLS) Protocol Version 1.2", RFC 5246, August 2008.
[RFC5987] Reschke, J., "Character Set and Language Encoding for
Hypertext Transfer Protocol (HTTP) Header Field
Parameters", RFC 5987, August 2010.
[RFC7230] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol [RFC7230] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol
(HTTP/1.1): Message Syntax and Routing", RFC 7230, (HTTP/1.1): Message Syntax and Routing", RFC 7230,
June 2014. June 2014.
[RFC7235] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol [RFC7235] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol
(HTTP/1.1): Authentication", RFC 7235, June 2014. (HTTP/1.1): Authentication", RFC 7235, June 2014.
18.2. Informative References 19.2. Informative References
[I-D.ietf-httpauth-mutual-algo] [I-D.ietf-httpauth-mutual-algo]
Oiwa, Y., Watanabe, H., Takagi, H., Maeda, K., Hayashi, Oiwa, Y., Watanabe, H., Takagi, H., Maeda, K., Hayashi,
T., and Y. Ioku, "Mutual Authentication Protocol for HTTP: T., and Y. Ioku, "Mutual Authentication Protocol for HTTP:
KAM3-based Cryptographic Algorithms", KAM3-based Cryptographic Algorithms",
draft-ietf-httpauth-mutual-algo-01 (work in progress), draft-ietf-httpauth-mutual-algo-02 (work in progress),
August 2014. February 2015.
[I-D.ietf-precis-framework] [I-D.ietf-precis-framework]
Saint-Andre, P. and M. Blanchet, "PRECIS Framework: Saint-Andre, P. and M. Blanchet, "PRECIS Framework:
Preparation and Comparison of Internationalized Strings in Preparation, Enforcement, and Comparison of
Application Protocols", draft-ietf-precis-framework-17 Internationalized Strings in Application Protocols",
(work in progress), May 2014. draft-ietf-precis-framework-22 (work in progress),
February 2015.
[ISO.10646-1.1993] [ISO.10646-1.1993]
International Organization for Standardization, International Organization for Standardization,
"Information Technology - Universal Multiple-octet coded "Information Technology - Universal Multiple-octet coded
Character Set (UCS) - Part 1: Architecture and Basic Character Set (UCS) - Part 1: Architecture and Basic
Multilingual Plane", ISO Standard 10646-1, May 1993. Multilingual Plane", ISO Standard 10646-1, May 1993.
[ITU.X690.1994] [ITU.X690.1994]
International Telecommunications Union, "Information International Telecommunications Union, "Information
Technology - ASN.1 encoding rules: Specification of Basic Technology - ASN.1 encoding rules: Specification of Basic
skipping to change at page 46, line 31 skipping to change at page 47, line 43
o Whether to keep ph() function for legacy migration or not. o Whether to keep ph() function for legacy migration or not.
o Adding test vectors for ensuring implementation correctness. o Adding test vectors for ensuring implementation correctness.
o Possibly adding a method for servers to detect availability of o Possibly adding a method for servers to detect availability of
Mutual authentication on client-side. Mutual authentication on client-side.
Appendix B. (Informative) Draft Change Log Appendix B. (Informative) Draft Change Log
B.1. Changes in Httpauth WG Revision 03 B.1. Changes in Httpauth WG Revision 04
o Merged httpauthprep proposal into general PRECIS Username/Password
profile.
o Adopting RFC 5987 extended syntax for non-ASCII parameter values.
o Refer draft-ietf-httpbis-auth-info for Authentication-Info header.
This results in a different syntax for that header.
B.2. Changes in Httpauth WG Revision 03
o Incompatible change: Single-port type authentication realm label o Incompatible change: Single-port type authentication realm label
has been changed to harmonize with Web Origin. (That is, the has been changed to harmonize with Web Origin. (That is, the
default ports (80 and 443) are to be omitted.) default ports (80 and 443) are to be omitted.)
B.2. Changes in Httpauth WG Revision 02 B.3. Changes in Httpauth WG Revision 02
o Major change: introduction of password-strengtheing function o Major change: introduction of password-strengtheing function
PBKDF2. PBKDF2.
o Changed Section 9 to adopt "list of requirements" style. Strict o Changed Section 10 to adopt "list of requirements" style. Strict
definition of state machine is now a derived, informational definition of state machine is now a derived, informational
definition. definition.
B.3. Changes in Httpauth WG Revision 01 B.4. Changes in Httpauth WG Revision 01
o Changed "tls-key" verification to "tls-unique" verification, and o Changed "tls-key" verification to "tls-unique" verification, and
"tls-cert" to "tls-server-end-point", adopting RFC 5929. "tls-cert" to "tls-server-end-point", adopting RFC 5929.
o Adopted [I-D.ietf-precis-framework]. o Adopted [I-D.ietf-precis-framework].
o Reverted reservation of "rekey-sid" and "rekey-method" parameters. o Reverted reservation of "rekey-sid" and "rekey-method" parameters.
o Degraded secure UI requirement to application note level, non- o Degraded secure UI requirement to application note level, non-
normative. normative.
o Adjusted levels of several requirements. o Adjusted levels of several requirements.
o Added warning text for handling of exceptional 5XX responses. o Added warning text for handling of exceptional 5XX responses.
o Dropped several references for optional authentications, except o Dropped several references for optional authentications, except
one "Note". one "Note".
o Several textual fixes, improvements and revisions. o Several textual fixes, improvements and revisions.
B.4. Changes in Httpauth Revision 00 B.5. Changes in Httpauth Revision 00
o Changed the version token. o Changed the version token.
o Renamed "verification tokens" to "Host verification tokens" and o Renamed "verification tokens" to "Host verification tokens" and
variables "v" to "vh" for clarification. (Back-ported from variables "v" to "vh" for clarification. (Back-ported from
draft-oiwa-httpauth-multihop-template-00) draft-oiwa-httpauth-multihop-template-00)
B.5. Changes in HttpBis Revision 00 B.6. Changes in HttpBis Revision 00
None. None.
B.6. Changes in Revision 12 B.7. Changes in Revision 12
o Added a reason "authz-failed". o Added a reason "authz-failed".
B.7. Changes in Revision 11 B.8. Changes in Revision 11
o Message syntax definition reverted to pre-07 style as httpbis-p1 o Message syntax definition reverted to pre-07 style as httpbis-p1
and p7 now defines a precise rule for parameter value parsing. and p7 now defines a precise rule for parameter value parsing.
o Replaced "stale" parameter with more infomative/extensive "reason" o Replaced "stale" parameter with more infomative/extensive "reason"
parameter in 401-INIT and 401-STALE. parameter in 401-INIT and 401-STALE.
o Reserved "rekey-sid" and "rekey-method" parameters for future o Reserved "rekey-sid" and "rekey-method" parameters for future
extensions. extensions.
o Added descriptions for replacing/non-replacing existing o Added descriptions for replacing/non-replacing existing
technologies. technologies.
B.8. Changes in Revision 10 B.9. Changes in Revision 10
o The authentication extension parts (non-mandatory authentication o The authentication extension parts (non-mandatory authentication
and authentication controls) are separated to yet another draft. and authentication controls) are separated to yet another draft.
o The default auth-domain parameter is changed to the full scheme- o The default auth-domain parameter is changed to the full scheme-
host-port syntax, which is consistent with usual HTTP host-port syntax, which is consistent with usual HTTP
authentication framework behavior. authentication framework behavior.
o Provision for application channel binding is added. o Provision for application channel binding is added.
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+------------+----------+-------------------------------------------+ +------------+----------+-------------------------------------------+
| S_c1, S_s1 | s_a, s_b | client/server-side secret randoms | | S_c1, S_s1 | s_a, s_b | client/server-side secret randoms |
| K_c1, K_s1 | w_a, w_b | client/server-side exchanged key | | K_c1, K_s1 | w_a, w_b | client/server-side exchanged key |
| | | components | | | | components |
| kc1, ks1 | wa, wb | parameter names for those | | kc1, ks1 | wa, wb | parameter names for those |
| VK_c, VK_s | o_a, o_b | client/server-side key verifiers | | VK_c, VK_s | o_a, o_b | client/server-side key verifiers |
| vkc, vks | oa, ob | parameter names for those | | vkc, vks | oa, ob | parameter names for those |
| z | z | session secrets | | z | z | session secrets |
+------------+----------+-------------------------------------------+ +------------+----------+-------------------------------------------+
B.9. Changes in Revision 09 B.10. Changes in Revision 09
o The (default) cryptographic algorithms are separated to another o The (default) cryptographic algorithms are separated to another
draft. draft.
o Names of the messages are changed to more informative ones than o Names of the messages are changed to more informative ones than
before. The following is the correspondence table of those names: before. The following is the correspondence table of those names:
+-------------------+-----------------+-----------------------------+ +-------------------+-----------------+-----------------------------+
| new name | old name | description | | new name | old name | description |
+-------------------+-----------------+-----------------------------+ +-------------------+-----------------+-----------------------------+
skipping to change at page 49, line 23 skipping to change at page 50, line 41
| req-KEX-C1 | req-A1 | client->server key exchange | | req-KEX-C1 | req-A1 | client->server key exchange |
| 401-KEX-S1 | 401-B1 | server->client key exchange | | 401-KEX-S1 | 401-B1 | server->client key exchange |
| req-VFY-C | req-A3 | client->server auth. | | req-VFY-C | req-A3 | client->server auth. |
| | | verification | | | | verification |
| 200-VFY-S | 200-B4 | server->client auth. | | 200-VFY-S | 200-B4 | server->client auth. |
| | | verification | | | | verification |
| 200-Optional-INIT | 200-Optional-B0 | initial with non-mandatory | | 200-Optional-INIT | 200-Optional-B0 | initial with non-mandatory |
| | | authentication | | | | authentication |
+-------------------+-----------------+-----------------------------+ +-------------------+-----------------+-----------------------------+
B.10. Changes in Revision 08 B.11. Changes in Revision 08
o The English text has been revised. o The English text has been revised.
B.11. Changes in Revision 07 B.12. Changes in Revision 07
o Adapt to httpbis HTTP/1.1 drafts: o Adapt to httpbis HTTP/1.1 drafts:
* Changed definition of extensive-token. * Changed definition of extensive-token.
* LWSP continuation-line (%0D.0A.20) deprecated. * LWSP continuation-line (%0D.0A.20) deprecated.
o To simplify the whole spec, the type of nonce-counter related o To simplify the whole spec, the type of nonce-counter related
parameters are change from hex-integer to integer. parameters are change from hex-integer to integer.
o Algorithm tokens are renamed to include names of hash algorithms. o Algorithm tokens are renamed to include names of hash algorithms.
o Clarified the session management, added details of server-side o Clarified the session management, added details of server-side
protocol decisions. protocol decisions.
o The whole draft was reorganized; introduction and overview has o The whole draft was reorganized; introduction and overview has
been rewritten. been rewritten.
B.12. Changes in Revision 06 B.13. Changes in Revision 06
o Integrated Optional Mutual Authentication to the main part. o Integrated Optional Mutual Authentication to the main part.
o Clarified the decision procedure for message recognitions. o Clarified the decision procedure for message recognitions.
o Clarified that a new authentication request for any sub-requests o Clarified that a new authentication request for any sub-requests
in interactive clients may be silently discarded. in interactive clients may be silently discarded.
o Typos and confusing phrases are fixed. o Typos and confusing phrases are fixed.
o Several "future considerations" are added. o Several "future considerations" are added.
B.13. Changes in Revision 05 B.14. Changes in Revision 05
o A new parameter called "version" is added for supporting future o A new parameter called "version" is added for supporting future
incompatible changes with a single implementation. In the (first) incompatible changes with a single implementation. In the (first)
final specification its value will be changed to 1. final specification its value will be changed to 1.
o A new header "Authentication-Control" is added for precise control o A new header "Authentication-Control" is added for precise control
of application-level authentication behavior. of application-level authentication behavior.
B.14. Changes in Revision 04 B.15. Changes in Revision 04
o Changed text of patent licenses: the phrase "once the protocol is o Changed text of patent licenses: the phrase "once the protocol is
accepted as an Internet standard" is removed so that the sentence accepted as an Internet standard" is removed so that the sentence
also covers the draft versions of this protocol. also covers the draft versions of this protocol.
o The "tls-key" verification is now OPTIONAL. o The "tls-key" verification is now OPTIONAL.
o Several description fixes and clarifications. o Several description fixes and clarifications.
B.15. Changes in Revision 03 B.16. Changes in Revision 03
o Wildcard domain specifications (e.g. "*.example.com") are allowed o Wildcard domain specifications (e.g. "*.example.com") are allowed
for auth-domain parameters (Section 4.1). for auth-domain parameters (Section 4.1).
o Specification of the tls-cert verification is updated o Specification of the tls-cert verification is updated
(incompatible change). (incompatible change).
o State transitions fixed. o State transitions fixed.
o Requirements for servers concerning w_a values are clarified. o Requirements for servers concerning w_a values are clarified.
o RFC references are updated. o RFC references are updated.
B.16. Changes in Revision 02 B.17. Changes in Revision 02
o Auth-realm is extended to allow full-scheme type. o Auth-realm is extended to allow full-scheme type.
o A decision diagram for clients and decision procedures for servers o A decision diagram for clients and decision procedures for servers
are added. are added.
o 401-B1 and req-A3 messages are changed to contain authentication o 401-B1 and req-A3 messages are changed to contain authentication
realm information. realm information.
o Bugs on equations for o_A and o_B are fixed. o Bugs on equations for o_A and o_B are fixed.
o Detailed equations for the entire algorithm are included. o Detailed equations for the entire algorithm are included.
o Elliptic-curve algorithms are updated. o Elliptic-curve algorithms are updated.
o Several clarifications and other minor updates. o Several clarifications and other minor updates.
B.17. Changes in Revision 01 B.18. Changes in Revision 01
o Several texts are rewritten for clarification. o Several texts are rewritten for clarification.
o Added several security consideration clauses. o Added several security consideration clauses.
Authors' Addresses Authors' Addresses
Yutaka Oiwa Yutaka Oiwa
National Institute of Advanced Industrial Science and Technology National Institute of Advanced Industrial Science and Technology
Research Institute for Secure Systems Research Institute for Secure Systems
3-11-46 Nakouji 3-11-46 Nakouji
Amagasaki, Hyogo Tsukuba Central 2
1-1-1 Umezono
Tsukuba-shi, Ibaraki
JP JP
Email: mutual-auth-contact-ml@aist.go.jp Email: mutual-auth-contact-ml@aist.go.jp
Hajime Watanabe Hajime Watanabe
National Institute of Advanced Industrial Science and Technology National Institute of Advanced Industrial Science and Technology
Research Institute for Secure Systems Research Institute for Secure Systems
Tsukuba Central 2 Tsukuba Central 2
1-1-1 Umezono 1-1-1 Umezono
Tsukuba-shi, Ibaraki Tsukuba-shi, Ibaraki
skipping to change at page 52, line 4 skipping to change at page 53, line 33
Tsukuba-shi, Ibaraki Tsukuba-shi, Ibaraki
JP JP
Hiromitsu Takagi Hiromitsu Takagi
National Institute of Advanced Industrial Science and Technology National Institute of Advanced Industrial Science and Technology
Research Institute for Secure Systems Research Institute for Secure Systems
Tsukuba Central 2 Tsukuba Central 2
1-1-1 Umezono 1-1-1 Umezono
Tsukuba-shi, Ibaraki Tsukuba-shi, Ibaraki
JP JP
Kaoru Maeda Kaoru Maeda
Lepidum Co. Ltd. Lepidum Co. Ltd.
#602, Village Sasazuka 3 Village Sasazuka 3, Suite #602
1-30-3 Sasazuka 1-30-3 Sasazuka
Shibuya-ku, Tokyo Shibuya-ku, Tokyo
JP JP
Tatsuya Hayashi Tatsuya Hayashi
Lepidum Co. Ltd. Lepidum Co. Ltd.
#602, Village Sasazuka 3 Village Sasazuka 3, Suite #602
1-30-3 Sasazuka 1-30-3 Sasazuka
Shibuya-ku, Tokyo Shibuya-ku, Tokyo
JP JP
Yuichi Ioku Yuichi Ioku
Individual Individual
 End of changes. 87 change blocks. 
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