draft-ietf-ace-oscore-profile-01.txt   draft-ietf-ace-oscore-profile-02.txt 
ACE Working Group L. Seitz ACE Working Group L. Seitz
Internet-Draft RISE SICS AB Internet-Draft RISE SICS AB
Intended status: Standards Track F. Palombini Intended status: Standards Track F. Palombini
Expires: September 6, 2018 Ericsson AB Expires: December 30, 2018 Ericsson AB
M. Gunnarsson M. Gunnarsson
RISE SICS AB RISE SICS AB
G. Selander G. Selander
Ericsson AB Ericsson AB
March 5, 2018 June 28, 2018
OSCORE profile of the Authentication and Authorization for Constrained OSCORE profile of the Authentication and Authorization for Constrained
Environments Framework Environments Framework
draft-ietf-ace-oscore-profile-01 draft-ietf-ace-oscore-profile-02
Abstract Abstract
This memo specifies a profile for the Authentication and This memo specifies a profile for the Authentication and
Authorization for Constrained Environments (ACE) framework. It Authorization for Constrained Environments (ACE) framework. It
utilizes Object Security for Constrained RESTful Environments utilizes Object Security for Constrained RESTful Environments
(OSCORE) to provide communication security, server authentication, (OSCORE) to provide communication security, server authentication,
and proof-of-possession for a key owned by the client and bound to an and proof-of-possession for a key owned by the client and bound to an
OAuth 2.0 access token. OAuth 2.0 access token.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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 https://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 September 6, 2018. This Internet-Draft will expire on December 30, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 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 (https://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
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Client to Resource Server . . . . . . . . . . . . . . . . . . 3 2. Client to Resource Server . . . . . . . . . . . . . . . . . . 3
2.1. Signaling the use of OSCORE . . . . . . . . . . . . . . . 3 2.1. Signaling the use of OSCORE . . . . . . . . . . . . . . . 3
2.2. Key establishment for OSCORE . . . . . . . . . . . . . . 4 2.2. Key establishment for OSCORE . . . . . . . . . . . . . . 4
3. Client to Authorization Server . . . . . . . . . . . . . . . 7 3. Client to Authorization Server . . . . . . . . . . . . . . . 8
4. Resource Server to Authorization Server . . . . . . . . . . . 7 4. Resource Server to Authorization Server . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8
6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 8 6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 9
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.1. Normative References . . . . . . . . . . . . . . . . . . 9 8.1. Normative References . . . . . . . . . . . . . . . . . . 10
8.2. Informative References . . . . . . . . . . . . . . . . . 10 8.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Profile Requirements . . . . . . . . . . . . . . . . 10 Appendix A. Profile Requirements . . . . . . . . . . . . . . . . 11
Appendix B. Using the pop-key with EDHOC (EDHOC+OSCORE) . . . . 11 Appendix B. Using the pop-key with EDHOC (EDHOC+OSCORE) . . . . 12
B.1. Using Asymmetric Keys . . . . . . . . . . . . . . . . . . 12 B.1. Using Asymmetric Keys . . . . . . . . . . . . . . . . . . 13
B.2. Using Symmetric Keys . . . . . . . . . . . . . . . . . . 13 B.2. Using Symmetric Keys . . . . . . . . . . . . . . . . . . 14
B.3. Processing . . . . . . . . . . . . . . . . . . . . . . . 15 B.3. Processing . . . . . . . . . . . . . . . . . . . . . . . 16
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 16 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction 1. Introduction
This memo specifies a profile of the ACE framework This memo specifies a profile of the ACE framework
[I-D.ietf-ace-oauth-authz]. In this profile, a client and a resource [I-D.ietf-ace-oauth-authz]. In this profile, a client and a resource
server use CoAP [RFC7252] to communicate. The client uses an access server use CoAP [RFC7252] to communicate. The client uses an access
token, bound to a key (the proof-of-possession key) to authorize its token, bound to a key (the proof-of-possession key) to authorize its
access to the resource server. In order to provide communication access to the resource server. In order to provide communication
security, proof of possession, and server authentication they use security, proof of possession, and server authentication they use
Object Security for Constrained RESTful Environments (OSCORE) Object Security for Constrained RESTful Environments (OSCORE)
skipping to change at page 3, line 39 skipping to change at page 3, line 39
document that a given resource on a specific RS is associated to a document that a given resource on a specific RS is associated to a
unique AS. unique AS.
2. Client to Resource Server 2. Client to Resource Server
The use of OSCORE for arbitrary CoAP messages is specified in The use of OSCORE for arbitrary CoAP messages is specified in
[I-D.ietf-core-object-security]. This section defines the specific [I-D.ietf-core-object-security]. This section defines the specific
uses and their purpose for securing the communication between a uses and their purpose for securing the communication between a
client and a resource server, and the parameters needed to negotiate client and a resource server, and the parameters needed to negotiate
the use of this profile with the token resource at the authorization the use of this profile with the token resource at the authorization
server as specified in section 5.6 of the ACE framework server as specified in section 5.6 of [I-D.ietf-ace-oauth-authz].
[I-D.ietf-ace-oauth-authz].
2.1. Signaling the use of OSCORE 2.1. Signaling the use of OSCORE
A client requests a token at an AS via the /token resource. This A client requests a token at an AS via the /token resource. This
follows the message formats specified in section 5.6.1 of the ACE follows the message formats specified in section 5.6.1 of
framework [I-D.ietf-ace-oauth-authz]. [I-D.ietf-ace-oauth-authz].
The AS responding to a successful access token request as defined in The AS responding to a successful access token request as defined in
section 5.6.2 of the ACE framework can signal that the use of OSCORE section 5.6.2 of [I-D.ietf-ace-oauth-authz] can signal that the use
is REQUIRED for a specific access token by including the "profile" of OSCORE is REQUIRED for a specific access token by including the
parameter with the value "coap_oscore" in the access token response. "profile" parameter with the value "coap_oscore" in the access token
This means that the client MUST use OSCORE towards all resource response. This means that the client MUST use OSCORE towards all
servers for which this access token is valid, and follow Section 2.2 resource servers for which this access token is valid, and follow
to derive the security context to run OSCORE. Section 2.2 to derive the security context to run OSCORE.
The error response procedures defined in section 5.6.3 of the ACE The error response procedures defined in section 5.6.3 of the ACE
framework are unchanged by this profile. framework are unchanged by this profile.
Note the the client and the authorization server MAY OPTIONALLY use Note the the client and the authorization server MAY OPTIONALLY use
OSCORE to protect the interaction via the /token resource. See OSCORE to protect the interaction via the /token resource. See
Section 3 for details. Section 3 for details.
2.2. Key establishment for OSCORE 2.2. Key establishment for OSCORE
Section 3.2 of OSCORE [I-D.ietf-core-object-security] defines how to Section 3.2 of [I-D.ietf-core-object-security] defines how to derive
derive a security context based on a shared master secret and a set a security context based on a shared master secret and a set of other
of other parameters, established between client and server. The parameters, established between client and server. The proof-of-
proof-of-possession key (pop-key) provisioned from the AS MAY, in possession key (pop-key) provisioned from the AS MAY, in case of pre-
case of pre-shared keys, be used directly as master secret in OSCORE. shared keys, be used directly as master secret in OSCORE.
If OSCORE is used directly with the symmetric pop-key as master If OSCORE is used directly with the symmetric pop-key as master
secret, then the AS MUST provision the following data, in response to secret, then the AS MUST provision the following data, in response to
the access token request: the access token request:
o a master secret o a master secret
o the sender identifier o the sender identifier
o the recipient identifier o the recipient identifier
Additionally, the AS MAY provision the following data, in the same Additionally, the AS MAY provision the following data, in the same
response. In case these parameters are omitted, the default values response. In case these parameters are omitted, the default values
are used as described in section 3.2 of are used as described in section 3.2 of
[I-D.ietf-core-object-security]. [I-D.ietf-core-object-security].
o an AEAD algorithm o an AEAD algorithm
o a KDF algorithm o a KDF algorithm
o a salt o a salt
o a replay window type and size o a replay window type and size
The master secret MUST be communicated as COSE_Key in the 'cnf' The master secret MUST be communicated as COSE_Key in the 'cnf'
parameter of the access token response as defined in section 5.6.4.5 parameter of the access token response as defined in Section 5.6.4.5
of [I-D.ietf-ace-oauth-authz]. The AEAD algorithm MAY be included as of [I-D.ietf-ace-oauth-authz]. The AEAD algorithm MAY be included as
the 'alg' parameter in the COSE_Key; the KDF algorithm MAY be the 'alg' parameter in the COSE_Key; the KDF algorithm MAY be
included as the 'kdf' parameter of the COSE_Key and the salt MAY be included as the 'kdf' parameter of the COSE_Key and the salt MAY be
included as the 'slt' parameter of the COSE_Key as defined in table included as the 'slt' parameter of the COSE_Key as defined in table
1. 1.
The same parameters MUST be included as metadata of the access token; The same parameters MUST be included as metadata of the access token;
if the token is a CWT [I-D.ietf-ace-cbor-web-token], the same if the token is a CWT [RFC8392], the same COSE_Key structure MUST be
COSE_Key structure MUST be placed in the 'cnf' claim of this token. placed in the 'cnf' claim of this token. If a CWT is used it MUST be
encrypted, since the token is transferred from the client to the RS
If a CWT is used it MUST be encrypted, since the token is transferred over an unprotected channel.
from the client to the RS over an unprotected channel.
The AS MUST also assign identifiers to both client and RS, which are The AS MUST also assign identifiers to both client and RS, which are
then used as Sender ID and Recipient ID in the OSCORE context as then used as Sender ID and Recipient ID in the OSCORE context as
described in section 3.1 of [I-D.ietf-core-object-security]. These described in section 3.1 of [I-D.ietf-core-object-security]. These
identifiers MUST be unique in the set of all clients and RS identifiers MUST be unique in the set of all clients and RS
identifiers for a certain AS. Moreover, these MUST be included in identifiers for a certain AS. Moreover, these MUST be included in
the COSE_Key as header parameters, as defined in table 1. the COSE_Key as header parameters, as defined in table 1.
We assume in this document that a resource is associated to one We assume in this document that a resource is associated to one
single AS, which makes it possible to assume unique identifiers for single AS, which makes it possible to assume unique identifiers for
skipping to change at page 5, line 29 skipping to change at page 6, line 8
case the RS needs to have a mechanism in place to disambiguate case the RS needs to have a mechanism in place to disambiguate
identifiers or mitigate their effect. identifiers or mitigate their effect.
Note that C should set the Sender ID of its security context to the Note that C should set the Sender ID of its security context to the
clientId value received and the Recipient ID to the serverId value, clientId value received and the Recipient ID to the serverId value,
and RS should do the opposite. and RS should do the opposite.
+----------+-------+--------------+------------+-------------------+ +----------+-------+--------------+------------+-------------------+
| name | label | CBOR type | registry | description | | name | label | CBOR type | registry | description |
+----------+-------+--------------+------------+-------------------+ +----------+-------+--------------+------------+-------------------+
| clientId | 6 | bstr | | Identifies the | | clientId | TBD1 | bstr | | Identifies the |
| | | | | client in an | | | | | | client in an |
| | | | | OSCORE context | | | | | | OSCORE context |
| | | | | using this key | | | | | | using this key |
| | | | | | | | | | | |
| serverId | 7 | bstr | | Identifies the | | serverId | TBD2 | bstr | | Identifies the |
| | | | | server in an | | | | | | server in an |
| | | | | OSCORE context | | | | | | OSCORE context |
| | | | | using this key | | | | | | using this key |
| | | | | | | | | | | |
| kdf | 8 | bstr | | Identifies the | | kdf | TBD3 | bstr | | Identifies the |
| | | | | KDF algorithm in | | | | | | KDF algorithm in |
| | | | | an OSCORE context | | | | | | an OSCORE context |
| | | | | using this key | | | | | | using this key |
| | | | | | | | | | | |
| slt | 9 | bstr | | Identifies the | | slt | TBD4 | bstr | | Identifies the |
| | | | | master salt in | | | | | | master salt in |
| | | | | an OSCORE context | | | | | | an OSCORE context |
| | | | | using this key | | | | | | using this key |
+----------+-------+--------------+------------+-------------------+ +----------+-------+--------------+------------+-------------------+
Table 1: Additional common header parameters for COSE_Key Table 1: Additional COSE_Key Common Parameters
Figure 1 shows an example of such an AS response, in CBOR diagnostic Figure 1 shows an example of such an AS response, in CBOR diagnostic
notation without the tag and value abbreviations. notation without the tag and value abbreviations.
Header: Created (Code=2.01) Header: Created (Code=2.01)
Content-Type: "application/cose+cbor" Content-Type: "application/cose+cbor"
Payload: Payload:
{ {
"access_token" : b64'SlAV32hkKG ... "access_token" : b64'SlAV32hkKG ...
(remainder of access token omitted for brevity)', (remainder of access token omitted for brevity)',
skipping to change at page 7, line 10 skipping to change at page 8, line 7
Note that the proof-of-possession required to bind the access token Note that the proof-of-possession required to bind the access token
to the client is implicitly performed by generating the shared OSCORE to the client is implicitly performed by generating the shared OSCORE
context using the pop-key as master secret, both on the client and RS context using the pop-key as master secret, both on the client and RS
side. An attacker using a stolen token will not be able to generate side. An attacker using a stolen token will not be able to generate
a valid OSCORE context and thus not be able to prove possession of a valid OSCORE context and thus not be able to prove possession of
the pop-key. the pop-key.
3. Client to Authorization Server 3. Client to Authorization Server
As specified in the ACE framework section 5.6 As specified in the ACE framework (section 5.6 of
[I-D.ietf-ace-oauth-authz], the Client and AS can also use CoAP [I-D.ietf-ace-oauth-authz]), the Client and AS can also use CoAP
instead of HTTP to communicate via the token resource. This section instead of HTTP to communicate via the token resource. This section
specifies how to use OSCORE between Client and AS together with CoAP. specifies how to use OSCORE between Client and AS together with CoAP.
The use of OSCORE for this communication is OPTIONAL in this profile, The use of OSCORE for this communication is OPTIONAL in this profile,
other security protocols (such as DTLS) MAY be used instead. other security protocols (such as DTLS) MAY be used instead.
The client and the AS are expected to have pre-established security The client and the AS are expected to have pre-established security
contexts in place. How these security contexts are established is contexts in place. How these security contexts are established is
out of scope for this profile. Furthermore the client and the AS out of scope for this profile. Furthermore the client and the AS
communicate using OSCORE ([I-D.ietf-core-object-security]) through communicate using OSCORE ([I-D.ietf-core-object-security]) through
the introspection resource as specified in section 5.7 of the introspection resource as specified in section 5.7 of
[I-D.ietf-ace-oauth-authz]. [I-D.ietf-ace-oauth-authz].
4. Resource Server to Authorization Server 4. Resource Server to Authorization Server
As specified in the ACE framework section 5.7 As specified in the ACE framework (section 5.7 of
[I-D.ietf-ace-oauth-authz], the RS and AS can also use CoAP instead [I-D.ietf-ace-oauth-authz]), the RS and AS can also use CoAP instead
of HTTP to communicate via the introspection resource. This section of HTTP to communicate via the introspection resource. This section
specifies how to use OSCORE between RS and AS. The use of OSCORE for specifies how to use OSCORE between RS and AS. The use of OSCORE for
this communication is OPTIONAL in this profile, other security this communication is OPTIONAL in this profile, other security
protocols (such as DTLS) MAY be used instead. protocols (such as DTLS) MAY be used instead.
The RS and the AS are expected to have pre-established security The RS and the AS are expected to have pre-established security
contexts in place. How these security contexts are established is contexts in place. How these security contexts are established is
out of scope for this profile. Furthermore the RS and the AS out of scope for this profile. Furthermore the RS and the AS
communicate using OSCORE ([I-D.ietf-core-object-security]) through communicate using OSCORE ([I-D.ietf-core-object-security]) through
the introspection resource as specified in section 5.7 of the introspection resource as specified in section 5.7 of
skipping to change at page 8, line 31 skipping to change at page 9, line 25
this paragraph. this paragraph.
The following registration is done for the ACE OAuth Profile Registry The following registration is done for the ACE OAuth Profile Registry
following the procedure specified in section 8.6 of following the procedure specified in section 8.6 of
[I-D.ietf-ace-oauth-authz]: [I-D.ietf-ace-oauth-authz]:
o Profile name: coap_oscore o Profile name: coap_oscore
o Profile Description: Profile for using OSCORE to secure o Profile Description: Profile for using OSCORE to secure
communication between constrained nodes using the Authentication communication between constrained nodes using the Authentication
and Authorization for Constrained Environments framework. and Authorization for Constrained Environments framework.
o Profile ID: 2 o Profile ID: TBD (value between 1 and 255)
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): [[this specification]] o Specification Document(s): [[this specification]]
The following registrations are done for the COSE Key Common The following registrations are done for the COSE Key Common
Parameter Registry specified in section 16.5 of [RFC8152]: Parameter Registry specified in section 16.5 of [RFC8152]:
o Name: clientId o Name: clientId
o Label: 6 o Label: TBD1 (value between 1 and 255)
o CBOR Type: bstr o CBOR Type: bstr
o Value Registry: N/A o Value Registry: N/A
o Description: Identifies the client in an OSCORE context o Description: Identifies the client in an OSCORE context
o Reference: [[this specification]] o Reference: [[this specification]]
o Name: serverId o Name: serverId
o Label: 7 o Label: TBD2 (value between 1 and 255)
o Value Type: bstr o Value Type: bstr
o Value Registry: N/A o Value Registry: N/A
o Description: Identifies the server in an OSCORE context o Description: Identifies the server in an OSCORE context
o Reference: [[this specification]] o Reference: [[this specification]]
o Name: kdf o Name: kdf
o Label: 8 o Label: TBD3 (value between 1 and 255)
o Value Type: bstr o Value Type: bstr
o Value Registry: COSE Algorithms registry o Value Registry: COSE Algorithms registry
o Description: Identifies the KDF algorithm to be used in an OSCORE o Description: Identifies the KDF algorithm to be used in an OSCORE
context context
o Reference: [[this specification]] o Reference: [[this specification]]
o Name: slt o Name: slt
o Label: 9 o Label: TBD4 (value between 1 and 255)
o Value Type: bstr o Value Type: bstr
o Value Registry: N/A o Value Registry: N/A
o Description: Identifies the master salt of to be used in an OSCORE o Description: Identifies the master salt of to be used in an OSCORE
context context
o Reference: [[this specification]] o Reference: [[this specification]]
8. References 8. References
8.1. Normative References 8.1. Normative References
[I-D.ietf-ace-cbor-web-token]
Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig,
"CBOR Web Token (CWT)", draft-ietf-ace-cbor-web-token-12
(work in progress), February 2018.
[I-D.ietf-ace-oauth-authz] [I-D.ietf-ace-oauth-authz]
Seitz, L., Selander, G., Wahlstroem, E., Erdtman, S., and Seitz, L., Selander, G., Wahlstroem, E., Erdtman, S., and
H. Tschofenig, "Authentication and Authorization for H. Tschofenig, "Authentication and Authorization for
Constrained Environments (ACE)", draft-ietf-ace-oauth- Constrained Environments (ACE) using the OAuth 2.0
authz-10 (work in progress), February 2018. Framework (ACE-OAuth)", draft-ietf-ace-oauth-authz-12
(work in progress), May 2018.
[I-D.ietf-core-object-security] [I-D.ietf-core-object-security]
Selander, G., Mattsson, J., Palombini, F., and L. Seitz, Selander, G., Mattsson, J., Palombini, F., and L. Seitz,
"Object Security for Constrained RESTful Environments "Object Security for Constrained RESTful Environments
(OSCORE)", draft-ietf-core-object-security-08 (work in (OSCORE)", draft-ietf-core-object-security-13 (work in
progress), January 2018. progress), June 2018.
[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, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, <https://www.rfc- DOI 10.17487/RFC2119, March 1997,
editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained [RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
Application Protocol (CoAP)", RFC 7252, Application Protocol (CoAP)", RFC 7252,
DOI 10.17487/RFC7252, June 2014, <https://www.rfc- DOI 10.17487/RFC7252, June 2014,
editor.org/info/rfc7252>. <https://www.rfc-editor.org/info/rfc7252>.
[RFC8152] Schaad, J., "CBOR Object Signing and Encryption (COSE)", [RFC8152] Schaad, J., "CBOR Object Signing and Encryption (COSE)",
RFC 8152, DOI 10.17487/RFC8152, July 2017, RFC 8152, DOI 10.17487/RFC8152, July 2017,
<https://www.rfc-editor.org/info/rfc8152>. <https://www.rfc-editor.org/info/rfc8152>.
[RFC8392] Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig,
"CBOR Web Token (CWT)", RFC 8392, DOI 10.17487/RFC8392,
May 2018, <https://www.rfc-editor.org/info/rfc8392>.
8.2. Informative References 8.2. Informative References
[I-D.gerdes-ace-dcaf-authorize] [I-D.gerdes-ace-dcaf-authorize]
Gerdes, S., Bergmann, O., and C. Bormann, "Delegated CoAP Gerdes, S., Bergmann, O., and C. Bormann, "Delegated CoAP
Authentication and Authorization Framework (DCAF)", draft- Authentication and Authorization Framework (DCAF)", draft-
gerdes-ace-dcaf-authorize-04 (work in progress), October gerdes-ace-dcaf-authorize-04 (work in progress), October
2015. 2015.
[I-D.ietf-ace-actors] [I-D.ietf-ace-actors]
Gerdes, S., Seitz, L., Selander, G., and C. Bormann, "An Gerdes, S., Seitz, L., Selander, G., and C. Bormann, "An
architecture for authorization in constrained architecture for authorization in constrained
environments", draft-ietf-ace-actors-06 (work in environments", draft-ietf-ace-actors-06 (work in
progress), November 2017. progress), November 2017.
[I-D.selander-ace-cose-ecdhe] [I-D.selander-ace-cose-ecdhe]
Selander, G., Mattsson, J., and F. Palombini, "Ephemeral Selander, G., Mattsson, J., and F. Palombini, "Ephemeral
Diffie-Hellman Over COSE (EDHOC)", draft-selander-ace- Diffie-Hellman Over COSE (EDHOC)", draft-selander-ace-
cose-ecdhe-07 (work in progress), July 2017. cose-ecdhe-08 (work in progress), March 2018.
[RFC4949] Shirey, R., "Internet Security Glossary, Version 2", [RFC4949] Shirey, R., "Internet Security Glossary, Version 2",
FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007, FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,
<https://www.rfc-editor.org/info/rfc4949>. <https://www.rfc-editor.org/info/rfc4949>.
[RFC6749] Hardt, D., Ed., "The OAuth 2.0 Authorization Framework", [RFC6749] Hardt, D., Ed., "The OAuth 2.0 Authorization Framework",
RFC 6749, DOI 10.17487/RFC6749, October 2012, RFC 6749, DOI 10.17487/RFC6749, October 2012,
<https://www.rfc-editor.org/info/rfc6749>. <https://www.rfc-editor.org/info/rfc6749>.
[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object [RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049, Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
October 2013, <https://www.rfc-editor.org/info/rfc7049>. October 2013, <https://www.rfc-editor.org/info/rfc7049>.
[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer [RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231, Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
DOI 10.17487/RFC7231, June 2014, <https://www.rfc- DOI 10.17487/RFC7231, June 2014,
editor.org/info/rfc7231>. <https://www.rfc-editor.org/info/rfc7231>.
Appendix A. Profile Requirements Appendix A. Profile Requirements
This section lists the specifications on this profile based on the This section lists the specifications on this profile based on the
requirements on the framework, as requested in Appendix C. of requirements on the framework, as requested in Appendix C of
[I-D.ietf-ace-oauth-authz]. [I-D.ietf-ace-oauth-authz].
o (Optional) discovery process of how the client finds the right AS o (Optional) discovery process of how the client finds the right AS
for an RS it wants to send a request to: Not specified for an RS it wants to send a request to: Not specified
o communication protocol the client and the RS must use: CoAP o communication protocol the client and the RS must use: CoAP
o security protocol the client and RS must use: OSCORE o security protocol the client and RS must use: OSCORE
o how the client and the RS mutually authenticate: Implicitly by o how the client and the RS mutually authenticate: Implicitly by
possession of a common OSCORE security context possession of a common OSCORE security context
o Content-format of the protocol messages: "application/cose+cbor" o Content-format of the protocol messages: "application/cose+cbor"
o proof-of-possession protocol(s) and how to select one; which key o proof-of-possession protocol(s) and how to select one; which key
types (e.g. symmetric/asymmetric) supported: OSCORE algorithms; types (e.g. symmetric/asymmetric) supported: OSCORE algorithms;
pre-established symmetric keys pre-established symmetric keys
o profile identifier: coap_oscore o profile identifier: coap_oscore
o (Optional) how the RS talks to the AS for introspection: HTTP/CoAP o (Optional) how the RS talks to the AS for introspection: HTTP/CoAP
(+ TLS/DTLS/OSCORE) (+ TLS/DTLS/OSCORE)
o how the client talks to the AS for requesting a token: HTTP/CoAP o how the client talks to the AS for requesting a token: HTTP/CoAP
(+ TLS/DTLS/OSCORE) (+ TLS/DTLS/OSCORE)
o how/if the /authz-info endpoint is protected: Security protocol o how/if the /authz-info endpoint is protected: Security protocol
skipping to change at page 11, line 48 skipping to change at page 12, line 44
o a symmetric or public key (associated to the RS) o a symmetric or public key (associated to the RS)
o a key identifier; o a key identifier;
How these parameters are communicated depends on the type of key How these parameters are communicated depends on the type of key
(asymmetric or symmetric). Moreover, the AS MUST signal the use of (asymmetric or symmetric). Moreover, the AS MUST signal the use of
OSCORE + EDHOC with the 'profile' parameter set to OSCORE + EDHOC with the 'profile' parameter set to
"coap_oscore_edhoc" and follow Appendix B to derive the security "coap_oscore_edhoc" and follow Appendix B to derive the security
context to run OSCORE. context to run OSCORE.
Note that in the case described in this section, the 'expires_in' Note that in the case described in this section, the 'expires_in'
parameter, defined in section 4.2.2. of [RFC6749] defines the parameter, defined in Section 4.2.2. of [RFC6749] defines the
lifetime in seconds of both the access token and the shared secret. lifetime in seconds of both the access token and the shared secret.
After expiration, C MUST acquire a new access token from the AS, and After expiration, C MUST acquire a new access token from the AS, and
run EDHOC again, as specified in this section run EDHOC again, as specified in this section
B.1. Using Asymmetric Keys B.1. Using Asymmetric Keys
In case of an asymmetric key, C MUST communicate its own asymmetric In case of an asymmetric key, C MUST communicate its own asymmetric
key to the AS in the 'cnf' parameter of the access token request, as key to the AS in the 'cnf' parameter of the access token request, as
specified in section 5.6.1 of [I-D.ietf-ace-oauth-authz]; the AS MUST specified in Section 5.6.1 of [I-D.ietf-ace-oauth-authz]; the AS MUST
communicate the RS's public key to C in the response, in the 'rs_cnf' communicate the RS's public key to C in the response, in the 'rs_cnf'
parameter, as specified in section 5.6.1 of parameter, as specified in Section 5.6.1 of
[I-D.ietf-ace-oauth-authz]. Note that the RS's public key MUST [I-D.ietf-ace-oauth-authz]. Note that the RS's public key MUST
include a 'kid' parameter, and that the value of the 'kid' MUST be include a 'kid' parameter, and that the value of the 'kid' MUST be
included in the access token, to let the RS know which of its public included in the access token, to let the RS know which of its public
keys C used. If the access token is a CWT keys C used. If the access token is a CWT [RFC8392], the key
[I-D.ietf-ace-cbor-web-token], the key identifier MUST be placed identifier MUST be placed directly in the 'cnf' structure (if the key
directly in the 'cnf' structure (if the key is only referenced). is only referenced).
Figure 3 shows an example of such a request in CBOR diagnostic Figure 3 shows an example of such a request in CBOR diagnostic
notation without tag and value abbreviations. notation without tag and value abbreviations.
Header: POST (Code=0.02) Header: POST (Code=0.02)
Uri-Host: "server.example.com" Uri-Host: "server.example.com"
Uri-Path: "token" Uri-Path: "token"
Content-Type: "application/cose+cbor" Content-Type: "application/cose+cbor"
Payload: Payload:
{ {
skipping to change at page 13, line 30 skipping to change at page 14, line 30
} }
} }
} }
Figure 4: Example AS response (EDHOC+OSCORE, asymmetric). Figure 4: Example AS response (EDHOC+OSCORE, asymmetric).
B.2. Using Symmetric Keys B.2. Using Symmetric Keys
In the case of a symmetric key, the AS MUST communicate the key to In the case of a symmetric key, the AS MUST communicate the key to
the client in the 'cnf' parameter of the access token response, as the client in the 'cnf' parameter of the access token response, as
specified in section 5.6.2. of [I-D.ietf-ace-oauth-authz]. AS MUST specified in Section 5.6.2. of [I-D.ietf-ace-oauth-authz]. AS MUST
also select a key identifier, that MUST be included as the 'kid' also select a key identifier, that MUST be included as the 'kid'
parameter either directly in the 'cnf' structure, as in figure 4 of parameter either directly in the 'cnf' structure, as in figure 4 of
[I-D.ietf-ace-oauth-authz], or as the 'kid' parameter of the [I-D.ietf-ace-oauth-authz], or as the 'kid' parameter of the
COSE_key, as in figure 6 of [I-D.ietf-ace-oauth-authz]. COSE_key, as in figure 6 of [I-D.ietf-ace-oauth-authz].
Figure 5 shows an example of the necessary parameters in the AS Figure 5 shows an example of the necessary parameters in the AS
response to the access token request when EDHOC is used. The example response to the access token request when EDHOC is used. The example
uses CBOR diagnostic notation without tag and value abbreviations. uses CBOR diagnostic notation without tag and value abbreviations.
Header: Created (Code=2.01) Header: Created (Code=2.01)
skipping to change at page 14, line 26 skipping to change at page 15, line 26
"kid" : b64'5tOS+h42dkw', "kid" : b64'5tOS+h42dkw',
"k" : b64'+a+Dg2jjU+eIiOFCa9lObw' "k" : b64'+a+Dg2jjU+eIiOFCa9lObw'
} }
} }
} }
Figure 5: Example AS response (EDHOC+OSCORE, symmetric). Figure 5: Example AS response (EDHOC+OSCORE, symmetric).
In both cases, the AS MUST also include the same key identifier as In both cases, the AS MUST also include the same key identifier as
'kid' parameter in the access token metadata. If the access token is 'kid' parameter in the access token metadata. If the access token is
a CWT [I-D.ietf-ace-cbor-web-token], the key identifier MUST be a CWT [RFC8392], the key identifier MUST be placed inside the 'cnf'
placed inside the 'cnf' claim as 'kid' parameter of the COSE_Key or claim as 'kid' parameter of the COSE_Key or directly in the 'cnf'
directly in the 'cnf' structure (if the key is only referenced). structure (if the key is only referenced).
Figure 6 shows an example CWT containing the necessary EDHOC+OSCORE Figure 6 shows an example CWT containing the necessary EDHOC+OSCORE
parameters in the 'cnf' claim, in CBOR diagnostic notation without parameters in the 'cnf' claim, in CBOR diagnostic notation without
tag and value abbreviations. tag and value abbreviations.
{ {
"aud" : "tempSensorInLivingRoom", "aud" : "tempSensorInLivingRoom",
"iat" : "1360189224", "iat" : "1360189224",
"exp" : "1360289224", "exp" : "1360289224",
"scope" : "temperature_g firmware_p", "scope" : "temperature_g firmware_p",
skipping to change at page 15, line 16 skipping to change at page 16, line 16
To provide forward secrecy and mutual authentication in the case of To provide forward secrecy and mutual authentication in the case of
pre-shared keys, pre-established raw public keys or with X.509 pre-shared keys, pre-established raw public keys or with X.509
certificates it is RECOMMENDED to use EDHOC certificates it is RECOMMENDED to use EDHOC
[I-D.selander-ace-cose-ecdhe] to generate the keying material. EDHOC [I-D.selander-ace-cose-ecdhe] to generate the keying material. EDHOC
MUST be used as defined in Appendix C of MUST be used as defined in Appendix C of
[I-D.selander-ace-cose-ecdhe], with the following additions and [I-D.selander-ace-cose-ecdhe], with the following additions and
modifications. modifications.
The first EDHOC message is sent after the access token is posted to The first EDHOC message is sent after the access token is posted to
the /authz-info resource of the RS as specified in section 5.8.1 of the /authz-info resource of the RS as specified in Section 5.8.1 of
[I-D.ietf-ace-oauth-authz]. Then the EDHOC message_1 is sent and the [I-D.ietf-ace-oauth-authz]. Then the EDHOC message_1 is sent and the
EDHOC protocol is initiated [I-D.selander-ace-cose-ecdhe]). EDHOC protocol is initiated [I-D.selander-ace-cose-ecdhe]).
Before the RS continues with the EDHOC protocol and responds to this Before the RS continues with the EDHOC protocol and responds to this
token submission request, additional verifications on the access token submission request, additional verifications on the access
token are done: the RS SHALL process the access token according to token are done: the RS SHALL process the access token according to
[I-D.ietf-ace-oauth-authz]. If the token is valid then the RS [I-D.ietf-ace-oauth-authz]. If the token is valid then the RS
continues processing EDHOC following Appendix C of continues processing EDHOC following Appendix C of
[I-D.selander-ace-cose-ecdhe], otherwise it discontinues EDHOC and [I-D.selander-ace-cose-ecdhe], otherwise it discontinues EDHOC and
responds with the error code as specified in responds with the error code as specified in
skipping to change at page 15, line 41 skipping to change at page 16, line 41
o If RS has an access token for C but not for the resource that C o If RS has an access token for C but not for the resource that C
has requested, RS MUST reject the request with a 4.03 (Forbidden). has requested, RS MUST reject the request with a 4.03 (Forbidden).
o If RS has an access token for C but it does not cover the action C o If RS has an access token for C but it does not cover the action C
requested on the resource, RS MUST reject the request with a 4.05 requested on the resource, RS MUST reject the request with a 4.05
(Method Not Allowed). (Method Not Allowed).
o If all verifications above succeeds, further communication between o If all verifications above succeeds, further communication between
client and RS is protected with OSCORE, including the RS response client and RS is protected with OSCORE, including the RS response
to the OSCORE request. to the OSCORE request.
In the case of EDHOC being used with symmetric keys, the protocol in In the case of EDHOC being used with symmetric keys, the protocol in
section 5 of [I-D.selander-ace-cose-ecdhe] MUST be used. If the key Section 5 of [I-D.selander-ace-cose-ecdhe] MUST be used. If the key
is asymmetric, the RS MUST also use an asymmetric key for is asymmetric, the RS MUST also use an asymmetric key for
authentication. This key is known to the client through the access authentication. This key is known to the client through the access
token response (see section 5.6.2 of [I-D.ietf-ace-oauth-authz]). In token response (see Section 5.6.2 of [I-D.ietf-ace-oauth-authz]). In
this case the protocol in section 4 of [I-D.selander-ace-cose-ecdhe] this case the protocol in Section 4 of [I-D.selander-ace-cose-ecdhe]
MUST be used. MUST be used.
Figure 7 illustrates the message exchanges for using OSCORE+EDHOC Figure 7 illustrates the message exchanges for using OSCORE+EDHOC
(step C in figure 1 of [I-D.ietf-ace-oauth-authz]). (step C in figure 1 of [I-D.ietf-ace-oauth-authz]).
Resource Resource
Client Server Client Server
| | | |
| | | |
+--------->| Header: POST (Code=0.02) +--------->| Header: POST (Code=0.02)
 End of changes. 51 change blocks. 
88 lines changed or deleted 92 lines changed or added

This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/