draft-ietf-ace-oscore-profile-09.txt   draft-ietf-ace-oscore-profile-10.txt 
ACE Working Group F. Palombini ACE Working Group F. Palombini
Internet-Draft Ericsson AB Internet-Draft Ericsson AB
Intended status: Standards Track L. Seitz Intended status: Standards Track L. Seitz
Expires: September 3, 2020 Combitech Expires: September 10, 2020 Combitech
G. Selander G. Selander
Ericsson AB Ericsson AB
M. Gunnarsson M. Gunnarsson
RISE RISE
March 2, 2020 March 9, 2020
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-09 draft-ietf-ace-oscore-profile-10
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.
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Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 3 2. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 4
3. Client-AS Communication . . . . . . . . . . . . . . . . . . . 6 3. Client-AS Communication . . . . . . . . . . . . . . . . . . . 6
3.1. C-to-AS: POST to token endpoint . . . . . . . . . . . . . 6 3.1. C-to-AS: POST to token endpoint . . . . . . . . . . . . . 6
3.2. AS-to-C: Access Token . . . . . . . . . . . . . . . . . . 8 3.2. AS-to-C: Access Token . . . . . . . . . . . . . . . . . . 8
3.2.1. OSCORE_Security_Context Object . . . . . . . . . . . 13 3.2.1. OSCORE_Security_Context Object . . . . . . . . . . . 13
4. Client-RS Communication . . . . . . . . . . . . . . . . . . . 16 4. Client-RS Communication . . . . . . . . . . . . . . . . . . . 16
4.1. C-to-RS: POST to authz-info endpoint . . . . . . . . . . 17 4.1. C-to-RS: POST to authz-info endpoint . . . . . . . . . . 17
4.1.1. The Nonce 1 Parameter . . . . . . . . . . . . . . . . 18
4.2. RS-to-C: 2.01 (Created) . . . . . . . . . . . . . . . . . 18 4.2. RS-to-C: 2.01 (Created) . . . . . . . . . . . . . . . . . 18
4.2.1. The Nonce 2 Parameter . . . . . . . . . . . . . . . . 19
4.3. OSCORE Setup . . . . . . . . . . . . . . . . . . . . . . 19 4.3. OSCORE Setup . . . . . . . . . . . . . . . . . . . . . . 19
4.4. Access rights verification . . . . . . . . . . . . . . . 21 4.4. Access rights verification . . . . . . . . . . . . . . . 21
5. Secure Communication with AS . . . . . . . . . . . . . . . . 21 5. Secure Communication with AS . . . . . . . . . . . . . . . . 21
6. Discarding the Security Context . . . . . . . . . . . . . . . 21 6. Discarding the Security Context . . . . . . . . . . . . . . . 21
7. Security Considerations . . . . . . . . . . . . . . . . . . . 22 7. Security Considerations . . . . . . . . . . . . . . . . . . . 22
8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 23 8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 23
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24
9.1. ACE OAuth Profile Registry . . . . . . . . . . . . . . . 24 9.1. ACE OAuth Profile Registry . . . . . . . . . . . . . . . 24
9.2. OSCORE Security Context Parameters Registry . . . . . . . 24 9.2. OAuth Parameters Registry . . . . . . . . . . . . . . . . 24
9.3. CWT Confirmation Methods Registry . . . . . . . . . . . . 25 9.3. OAuth Parameters CBOR Mappings Registry . . . . . . . . . 24
9.4. JWT Confirmation Methods Registry . . . . . . . . . . . . 25 9.4. OSCORE Security Context Parameters Registry . . . . . . . 25
9.5. Expert Review Instructions . . . . . . . . . . . . . . . 25 9.5. CWT Confirmation Methods Registry . . . . . . . . . . . . 25
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 26 9.6. JWT Confirmation Methods Registry . . . . . . . . . . . . 26
10.1. Normative References . . . . . . . . . . . . . . . . . . 26 9.7. Expert Review Instructions . . . . . . . . . . . . . . . 26
10.2. Informative References . . . . . . . . . . . . . . . . . 27 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
10.1. Normative References . . . . . . . . . . . . . . . . . . 27
10.2. Informative References . . . . . . . . . . . . . . . . . 28
Appendix A. Profile Requirements . . . . . . . . . . . . . . . . 28 Appendix A. Profile Requirements . . . . . . . . . . . . . . . . 28
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 28 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29
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. Note that this profile uses a access to the resource server. Note that this profile uses a
symmetric-crypto-based scheme, where the symmetric secret is used as symmetric-crypto-based scheme, where the symmetric secret is used as
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context to run OSCORE. Usually it is assumed that constrained context to run OSCORE. Usually it is assumed that constrained
devices will be pre-configured with the necessary profile, so that devices will be pre-configured with the necessary profile, so that
this kind of profile negotiation can be omitted. this kind of profile negotiation can be omitted.
Moreover, the AS MUST send the following data: Moreover, the AS MUST send the following data:
o a master secret o a master secret
o a server identifier o a server identifier
o a client identifier
Additionally, the AS MAY send the following data, in the same Additionally, the AS MAY send the following data, in the same
response. response.
o a client identifier
o a context identifier o a context identifier
o an AEAD algorithm o an AEAD algorithm
o an HKDF algorithm o an HKDF algorithm
o a salt o a salt
o the OSCORE version number o the OSCORE version number
The OSCORE_Security_Context is a CBOR map object, defined in The OSCORE_Security_Context is a CBOR map object, defined in
Section 3.2.1. This object is transported in the 'cnf' parameter of Section 3.2.1. This object is transported in the 'cnf' parameter of
the access token response as defined in Section 3.2 of the access token response as defined in Section 3.2 of
[I-D.ietf-ace-oauth-params], as value of a field named 'osc' [I-D.ietf-ace-oauth-params], as value of a field named 'osc'
registered in Section 9.3 and Section 9.4. The master secret MUST be registered in Section 9.5 and Section 9.6. The master secret MUST be
communicated as the 'ms' field in the 'osc' field in the 'cnf' communicated as the 'ms' field in the 'osc' field in the 'cnf'
parameter of the access token response as defined in Section 3.2 of parameter of the access token response as defined in Section 3.2 of
[I-D.ietf-ace-oauth-params]. The AEAD algorithm may be included as [I-D.ietf-ace-oauth-params]. The AEAD algorithm may be included as
the 'alg' parameter in the OSCORE_Security_Context; the HKDF the 'alg' parameter in the OSCORE_Security_Context; the HKDF
algorithm may be included as the 'hkdf' parameter of the algorithm may be included as the 'hkdf' parameter of the
OSCORE_Security_Context, a salt may be included as the 'salt' OSCORE_Security_Context, a salt may be included as the 'salt'
parameter of the OSCORE_Security_Context, and the OSCORE version parameter of the OSCORE_Security_Context, and the OSCORE version
number may be included as the 'version' parameter of the number may be included as the 'version' parameter of the
OSCORE_Security_Context. OSCORE_Security_Context.
The same parameters MUST be included as part of the access token. The same parameters MUST be included as part of the access token.
This profile RECOMMENDS the use of CBOR web token (CWT) as specified This profile RECOMMENDS the use of CBOR web token (CWT) as specified
in [RFC8392]. If the token is a CWT, the same in [RFC8392]. If the token is a CWT, the same
OSCORE_Security_Context structure defined above MUST be placed in the OSCORE_Security_Context structure defined above MUST be placed in the
'osc' field of the 'cnf' claim of this token. The access token MUST 'osc' field of the 'cnf' claim of this token. The access token MUST
be encrypted, since it will be transferred from the client to the RS be encrypted, since it will be transferred from the client to the RS
over an unprotected channel. over an unprotected channel.
The AS MUST also assign an identifier to the RS (serverId), MAY The AS MUST also assign an identifier to the RS (serverId), and to
assign an identifier to the client (clientId), and MAY assign an the client (clientId), and MAY assign an identifier to the context
identifier to the context (contextId). These identifiers are then (contextId). These identifiers are then used as Sender ID, Recipient
used as Sender ID, Recipient ID and ID Context in the OSCORE context ID and ID Context in the OSCORE context as described in section 3.1
as described in section 3.1 of [RFC8613]. Applications need to of [RFC8613]. Applications need to consider that these identifiers
consider that these identifiers are sent in the clear and may reveal are sent in the clear and may reveal information about the endpoints,
information about the endpoints, as mentioned in section 12.8 of as mentioned in section 12.8 of [RFC8613]. The pair (client
[RFC8613]. The pair (client identifier, context identifier) MUST be identifier, context identifier) MUST be unique in the set of all
unique in the set of all clients for a single RS. Moreover, clients for a single RS. Moreover, clientId, serverId and (when
clientId, serverId and (when assigned) contextId MUST be included in assigned) contextId MUST be included in the OSCORE_Security_Context,
the OSCORE_Security_Context, as defined in Section 3.2.1. as defined in Section 3.2.1.
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 for the AS to enforce uniqueness single AS, which makes it possible for the AS to enforce uniqueness
of identifiers for each client requesting a particular resource to a of identifiers for each client requesting a particular resource to a
RS. If this is not the case, collisions of identifiers may occur at RS. If this is not the case, collisions of identifiers may occur at
the RS, in which case the RS needs to have a mechanism in place to the RS, in which case the RS needs to have a mechanism in place to
disambiguate identifiers or mitigate the effect of the collisions. disambiguate identifiers or mitigate the effect of the collisions.
Moreover, implementers of this specification need to be aware that if
other authentication mechanisms are used to set up OSCORE between the
same client and RS, that do not rely on AS assigning identifiers,
collisions may happen and need to be mitigated.
Note that in Section 4.3 C sets the Sender ID of its Security Context Note that in Section 4.3 C sets the Sender ID of its Security Context
to the clientId value received and the Recipient ID to the serverId to the clientId value received and the Recipient ID to the serverId
value, and RS does the opposite. value, and RS does the opposite.
Figure 5 shows an example of an AS response, with payload in CBOR Figure 5 shows an example of an AS response, with payload in CBOR
diagnostic notation without the tag and value abbreviations. The diagnostic notation without the tag and value abbreviations. The
access token has been truncated for readability. access token has been truncated for readability.
Header: Created (Code=2.01) Header: Created (Code=2.01)
Content-Type: "application/ace+cbor" Content-Type: "application/ace+cbor"
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An OSCORE_Security_Context is an object that represents part or all An OSCORE_Security_Context is an object that represents part or all
of an OSCORE Security Context, i.e., the local set of information of an OSCORE Security Context, i.e., the local set of information
elements necessary to carry out the cryptographic operations in elements necessary to carry out the cryptographic operations in
OSCORE (Section 3.1 of [RFC8613]). In particular, the OSCORE (Section 3.1 of [RFC8613]). In particular, the
OSCORE_Security_Context object is defined to be serialized and OSCORE_Security_Context object is defined to be serialized and
transported between nodes, as specified by this document, but can transported between nodes, as specified by this document, but can
also be used in this way by other specifications if needed. The also be used in this way by other specifications if needed. The
OSCORE_Security_Context object can either be encoded as a JSON object OSCORE_Security_Context object can either be encoded as a JSON object
or as a CBOR map. The set of common parameters that can appear in an or as a CBOR map. The set of common parameters that can appear in an
OSCORE_Security_Context object can be found in the IANA "OSCORE OSCORE_Security_Context object can be found in the IANA "OSCORE
Security Context Parameters" registry (Section 9.2), defined for Security Context Parameters" registry (Section 9.4), defined for
extensibility, and is specified below. All parameters are optional. extensibility, and is specified below. All parameters are optional.
Table 1 provides a summary of the OSCORE_Security_Context parameters Table 1 provides a summary of the OSCORE_Security_Context parameters
defined in this section. defined in this section.
+-----------+-------+----------------+--------------+---------------+ +-----------+-------+----------------+--------------+---------------+
| name | CBOR | CBOR type | registry | description | | name | CBOR | CBOR type | registry | description |
| | label | | | | | | label | | | |
+-----------+-------+----------------+--------------+---------------+ +-----------+-------+----------------+--------------+---------------+
| version | 0 | int | | OSCORE | | version | 0 | int | | OSCORE |
| | | | | Version | | | | | | Version |
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described in section 5.8.1 of [I-D.ietf-ace-oauth-authz] to transport described in section 5.8.1 of [I-D.ietf-ace-oauth-authz] to transport
the token and N1 to the RS. the token and N1 to the RS.
Note that the use of the payload and the Content-Format is different Note that the use of the payload and the Content-Format is different
from what described in section 5.8.1 of [I-D.ietf-ace-oauth-authz], from what described in section 5.8.1 of [I-D.ietf-ace-oauth-authz],
which only transports the token without any CBOR wrapping. In this which only transports the token without any CBOR wrapping. In this
profile, the client MUST wrap the token and N1 in a CBOR map. The profile, the client MUST wrap the token and N1 in a CBOR map. The
client MUST use the Content-Format "application/ace+cbor" defined in client MUST use the Content-Format "application/ace+cbor" defined in
section 8.14 of [I-D.ietf-ace-oauth-authz]. The client MUST include section 8.14 of [I-D.ietf-ace-oauth-authz]. The client MUST include
the access token using the correct CBOR label (e.g., "cwt" for CWT, the access token using the correct CBOR label (e.g., "cwt" for CWT,
"jwt" for JWT) and N1 using the 'cnonce' parameter defined in section "jwt" for JWT) and N1 using the 'nonce1' parameter defined in
5.1.2 of [I-D.ietf-ace-oauth-authz]. Section 4.1.1.
The authz-info endpoint is not protected, nor are the responses from The authz-info endpoint is not protected, nor are the responses from
this resource. this resource.
The access token MUST be encrypted, since it is transferred from the The access token MUST be encrypted, since it is transferred from the
client to the RS over an unprotected channel. client to the RS over an unprotected channel.
Note that a client may be required to re-POST the access token in Note that a client may be required to re-POST the access token in
order to complete a request, since an RS may delete a stored access order to complete a request, since an RS may delete a stored access
token at any time, for example due to all storage space being token at any time, for example due to all storage space being
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readability. readability.
Header: POST (Code=0.02) Header: POST (Code=0.02)
Uri-Host: "rs.example.com" Uri-Host: "rs.example.com"
Uri-Path: "authz-info" Uri-Path: "authz-info"
Content-Format: "application/ace+cbor" Content-Format: "application/ace+cbor"
Payload: Payload:
{ {
"access_token": h'a5037674656d7053656e73 ... "access_token": h'a5037674656d7053656e73 ...
(remainder of access token (CWT) omitted for brevity)', (remainder of access token (CWT) omitted for brevity)',
"cnonce": h'018a278f7faab55a' "nonce1": h'018a278f7faab55a'
} }
Figure 11: Example C-to-RS POST /authz-info request using CWT Figure 11: Example C-to-RS POST /authz-info request using CWT
4.1.1. The Nonce 1 Parameter
This parameter MUST be sent from the client to the RS, together with
the access token, if the ace profile used is coap_oscore. The
parameter is encoded as a byte string for CBOR-based interactions,
and as a string (Base64 encoded binary) for JSON-based interactions.
This parameter is registered in Section 9.2.
4.2. RS-to-C: 2.01 (Created) 4.2. RS-to-C: 2.01 (Created)
The RS MUST follow the procedures defined in section 5.8.1 of The RS MUST follow the procedures defined in section 5.8.1 of
[I-D.ietf-ace-oauth-authz]: the RS must verify the validity of the [I-D.ietf-ace-oauth-authz]: the RS must verify the validity of the
token. If the token is valid, the RS must respond to the POST token. If the token is valid, the RS must respond to the POST
request with 2.01 (Created). If the token is valid but is associated request with 2.01 (Created). If the token is valid but is associated
to claims that the RS cannot process (e.g., an unknown scope), or if to claims that the RS cannot process (e.g., an unknown scope), or if
any of the expected parameters in the 'osc' is missing (e.g., any of any of the expected parameters in the 'osc' is missing (e.g., any of
the mandatory parameters from the AS), or if any parameters received the mandatory parameters from the AS), or if any parameters received
in the 'osc' is unrecognized, the RS must respond with an error in the 'osc' is unrecognized, the RS must respond with an error
response code equivalent to the CoAP code 4.00 (Bad Request). In the response code equivalent to the CoAP code 4.00 (Bad Request). In the
latter two cases, the RS may provide additional information in the latter two cases, the RS may provide additional information in the
error response, in order to clarify what went wrong. The RS may make error response, in order to clarify what went wrong. The RS may make
an introspection request to validate the token before responding to an introspection request to validate the token before responding to
the POST request to the authz-info endpoint. the POST request to the authz-info endpoint.
Additionally, the RS MUST generate a nonce N2 very unlikely to have Additionally, the RS MUST generate a nonce N2 very unlikely to have
been previously used with the same input keying material, and send it been previously used with the same input keying material, and send it
within the 2.01 (Created) response. The payload of the 2.01 within the 2.01 (Created) response. The payload of the 2.01
(Created) response MUST be a CBOR map containing the 'cnonce' (Created) response MUST be a CBOR map containing the 'nonce2'
parameter defined in section 5.1.2 of [I-D.ietf-ace-oauth-authz], set parameter defined in Section 4.2.1, set to N2. This profile
to N2. This profile RECOMMENDS to use a 64-bit long random number as RECOMMENDS to use a 64-bit long random number as nonce's value. The
nonce's value. Moreover, if the 'osc' field in the token did not RS MUST use the Content-Format "application/ace+cbor" defined in
contain a 'clientId' parameter, the RS MUST generate an identifier, section 8.14 of [I-D.ietf-ace-oauth-authz].
unique in the set of all its existing client identifiers, and send it
in a 'clientId' parameter in the CBOR map as a CBOR bstr. The RS MAY
generate and send a 'ClientId' identifier even though the 'osc' field
contained such a parameter, in order to guarantee the uniqueness of
the client identifier. The RS MUST use the Content-Format
"application/ace+cbor" defined in section 8.14 of
[I-D.ietf-ace-oauth-authz].
Figure 12 shows an example of the response sent from the RS to the Figure 12 shows an example of the response sent from the RS to the
client, with payload in CBOR diagnostic notation without the tag and client, with payload in CBOR diagnostic notation without the tag and
value abbreviations. value abbreviations.
Header: Created (Code=2.01) Header: Created (Code=2.01)
Content-Format: "application/ace+cbor" Content-Format: "application/ace+cbor"
Payload: Payload:
{ {
"cnonce": h'25a8991cd700ac01' "nonce2": h'25a8991cd700ac01'
} }
Figure 12: Example RS-to-C 2.01 (Created) response Figure 12: Example RS-to-C 2.01 (Created) response
As specified in section 5.8.1 of [I-D.ietf-ace-oauth-authz], when As specified in section 5.8.1 of [I-D.ietf-ace-oauth-authz], when
receiving an updated access token with updated authorization receiving an updated access token with updated authorization
information from the client (see Section 3.1), it is recommended that information from the client (see Section 3.1), it is recommended that
the RS overwrites the previous token, that is only the latest the RS overwrites the previous token, that is only the latest
authorization information in the token received by the RS is valid. authorization information in the token received by the RS is valid.
This simplifies for the RS to keep track of authorization information This simplifies for the RS to keep track of authorization information
for a given client. for a given client.
As specified in section 5.8.3 of [I-D.ietf-ace-oauth-authz], the RS As specified in section 5.8.3 of [I-D.ietf-ace-oauth-authz], the RS
must notify the client with an error response with code 4.01 must notify the client with an error response with code 4.01
(Unauthorized) for any long running request before terminating the (Unauthorized) for any long running request before terminating the
session, when the access token expires. session, when the access token expires.
4.2.1. The Nonce 2 Parameter
This parameter MUST be sent from the RS to the Client if the ace
profile used is coap_oscore. The parameter is encoded as a byte
string for CBOR-based interactions, and as a string (Base64 encoded
binary) for JSON-based interactions. This parameter is registered in
Section 9.2
4.3. OSCORE Setup 4.3. OSCORE Setup
Once receiving the 2.01 (Created) response from the RS, following the Once receiving the 2.01 (Created) response from the RS, following the
POST request to authz-info endpoint, the client MUST extract the CBOR POST request to authz-info endpoint, the client MUST extract the CBOR
bstr nonce N2 from the 'cnonce' parameter and the client identifier bstr nonce N2 from the 'nonce2' parameter in the CBOR map in the
from the 'clientId' in the CBOR map in the payload of the response. payload of the response. Then, the client MUST set the Master Salt
Then, the client MUST set the Master Salt of the Security Context of the Security Context created to communicate with the RS to the
created to communicate with the RS to the concatenation of salt, N1, concatenation of salt, N1, and N2, in this order: Master Salt =
and N2, in this order: Master Salt = salt | N1 | N2, where | denotes salt | N1 | N2, where | denotes byte string concatenation, where salt
byte string concatenation, where salt was received from the AS in was received from the AS in Section 3.2, and where N1 and N2 are the
Section 3.2, and where N1 and N2 are the two nonces encoded as CBOR two nonces encoded as CBOR bstr. The client MUST set the Master
bstr. The client MUST set the Master Secret and Recipient ID from Secret, Sender ID and Recipient ID from the parameters received from
the parameters received from the AS in Section 3.2. The client MUST the AS in Section 3.2. The client MUST set the AEAD Algorithm, ID
set the AEAD Algorithm, ID Context, HKDF, and OSCORE Version from the Context, HKDF, and OSCORE Version from the parameters received from
parameters received from the AS in Section 3.2, if present. In case the AS in Section 3.2, if present. In case these parameters are
these parameters are omitted, the default values are used as omitted, the default values are used as described in sections 3.2 and
described in sections 3.2 and 5.4 of [RFC8613]. The client MUST set 5.4 of [RFC8613]. After that, the client MUST derive the complete
the Sender ID from the 'clientId in the 2.01 (Created) response, if Security Context following section 3.2.1 of [RFC8613]. From this
present; otherwise, the client MUST set the Sender ID from the point on, the client MUST use this Security Context to communicate
parameters received from the AS in Section 3.2. After that, the with the RS when accessing the resources as specified by the
client MUST derive the complete Security Context following section authorization information.
3.2.1 of [RFC8613]. From this point on, the client MUST use this
Security Context to communicate with the RS when accessing the
resources as specified by the authorization information.
If any of the expected parameters is missing (e.g., any of the If any of the expected parameters is missing (e.g., any of the
mandatory parameters from the AS, or the 'clientId', either received mandatory parameters from the AS, the client MUST stop the exchange,
from the AS or in the 2.01 (Created) response from the RS), the and MUST NOT derive the Security Context. The client MAY restart the
client MUST stop the exchange, and MUST NOT derive the Security exchange, to get the correct security material.
Context. The client MAY restart the exchange, to get the correct
security material.
The client then uses this Security Context to send requests to RS The client then uses this Security Context to send requests to RS
using OSCORE. using OSCORE.
After sending the 2.01 (Created) response, the RS MUST set the Master After sending the 2.01 (Created) response, the RS MUST set the Master
Salt of the Security Context created to communicate with the client Salt of the Security Context created to communicate with the client
to the concatenation of salt, N1, and N2, in this order: Master Salt to the concatenation of salt, N1, and N2, in this order: Master Salt
= salt | N1 | N2, where | denotes byte string concatenation, where = salt | N1 | N2, where | denotes byte string concatenation, where
salt was received from the AS in Section 4.2, and where N1 and N2 are salt was received from the AS in Section 4.2, and where N1 and N2 are
the two nonces encoded as CBOR bstr. The RS MUST set the Master the two nonces encoded as CBOR bstr. The RS MUST set the Master
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responses are used, as specified in section 8 of [RFC8613]. responses are used, as specified in section 8 of [RFC8613].
Additionally, if OSCORE verification succeeds, the verification of Additionally, if OSCORE verification succeeds, the verification of
access rights is performed as described in section Section 4.4. The access rights is performed as described in section Section 4.4. The
RS MUST NOT use the Security Context after the related token has RS MUST NOT use the Security Context after the related token has
expired, and MUST respond with a unprotected 4.01 (Unauthorized) expired, and MUST respond with a unprotected 4.01 (Unauthorized)
error message to requests received that correspond to a Security error message to requests received that correspond to a Security
Context with an expired token. Context with an expired token.
If the exchange was an update of access rights, i.e., a new Security If the exchange was an update of access rights, i.e., a new Security
Context was derived from a client that already had a Security Context Context was derived from a client that already had a Security Context
in place, the is RECOMMENDED to delete the old Security Context after in place, the RS is RECOMMENDED to delete the old Security Context
OSCORE verification and verification of access rights succeed. The after OSCORE verification and verification of access rights succeed.
RS MUST delete the Security Context if it deletes the access token The RS MUST delete the Security Context if it deletes the access
associated to it. token associated to it.
4.4. Access rights verification 4.4. Access rights verification
The RS MUST follow the procedures defined in section 5.8.2 of The RS MUST follow the procedures defined in section 5.8.2 of
[I-D.ietf-ace-oauth-authz]: if an RS receives an OSCORE-protected [I-D.ietf-ace-oauth-authz]: if an RS receives an OSCORE-protected
request from a client, then the RS processes it according to request from a client, then the RS processes it according to
[RFC8613]. If OSCORE verification succeeds, and the target resource [RFC8613]. If OSCORE verification succeeds, and the target resource
requires authorization, the RS retrieves the authorization requires authorization, the RS retrieves the authorization
information using the access token associated to the Security information using the access token associated to the Security
Context. The RS then must verify that the authorization information Context. The RS then must verify that the authorization information
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[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: TBD (value between 1 and 255) 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]]
9.2. OSCORE Security Context Parameters Registry 9.2. OAuth Parameters Registry
The following registrations are done for the OAuth Parameters
Registry following the procedure specified in section 11.2 of
[RFC6749]:
o Parameter name: nonce1
o Parameter usage location: token request
o Change Controller: IESG
o Specification Document(s): [[this specification]]
o Parameter name: nonce2
o Parameter usage location: token response
o Change Controller: IESG
o Specification Document(s): [[this specification]]
9.3. OAuth Parameters CBOR Mappings Registry
The following registrations are done for the OAuth Parameters CBOR
Mappings Registry following the procedure specified in section 8.9 of
[I-D.ietf-ace-oauth-authz]:
o Name: nonce1
o CBOR Key: TBD1
o Value Type: bstr
o Reference: [[this specification]]
o Name: nonce2
o CBOR Key: TBD2
o Value Type: IESG
o Reference: [[this specification]]
9.4. OSCORE Security Context Parameters Registry
It is requested that IANA create a new registry entitled "OSCORE It is requested that IANA create a new registry entitled "OSCORE
Security Context Parameters" registry. The registry is to be created Security Context Parameters" registry. The registry is to be created
as Expert Review Required. Guidelines for the experts is provided as Expert Review Required. Guidelines for the experts is provided
Section 9.5. It should be noted that in addition to the expert Section 9.7. It should be noted that in addition to the expert
review, some portions of the registry require a specification, review, some portions of the registry require a specification,
potentially on standards track, be supplied as well. potentially on standards track, be supplied as well.
The columns of the registry are: The columns of the registry are:
name The JSON name requested (e.g., "ms"). Because a core goal of name The JSON name requested (e.g., "ms"). Because a core goal of
this specification is for the resulting representations to be this specification is for the resulting representations to be
compact, it is RECOMMENDED that the name be short. This name is compact, it is RECOMMENDED that the name be short. This name is
case sensitive. Names may not match other registered names in a case sensitive. Names may not match other registered names in a
case-insensitive manner unless the Designated Experts determine case-insensitive manner unless the Designated Experts determine
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registry This field denotes the registry that values may come from, registry This field denotes the registry that values may come from,
if one exists. if one exists.
description This field contains a brief description for the field. description This field contains a brief description for the field.
specification This contains a pointer to the public specification specification This contains a pointer to the public specification
for the field if one exists for the field if one exists
This registry will be initially populated by the values in Table 1. This registry will be initially populated by the values in Table 1.
The specification column for all of these entries will be this The specification column for all of these entries will be this
document and [RFC8613]. document and [RFC8613].
9.3. CWT Confirmation Methods Registry 9.5. CWT Confirmation Methods Registry
The following registration is done for the CWT Confirmation Methods The following registration is done for the CWT Confirmation Methods
Registry following the procedure specified in section 7.2.1 of Registry following the procedure specified in section 7.2.1 of
[I-D.ietf-ace-cwt-proof-of-possession]: [I-D.ietf-ace-cwt-proof-of-possession]:
o Confirmation Method Name: "osc" o Confirmation Method Name: "osc"
o Confirmation Method Description: OSCORE_Security_Context carrying o Confirmation Method Description: OSCORE_Security_Context carrying
the parameters for using OSCORE per-message security with implicit the parameters for using OSCORE per-message security with implicit
key confirmation key confirmation
o Confirmation Key: TBD (value between 4 and 255) o Confirmation Key: TBD (value between 4 and 255)
o Confirmation Value Type(s): map o Confirmation Value Type(s): map
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.2.1 of [[this specification]] o Specification Document(s): Section 3.2.1 of [[this specification]]
9.4. JWT Confirmation Methods Registry 9.6. JWT Confirmation Methods Registry
The following registration is done for the JWT Confirmation Methods The following registration is done for the JWT Confirmation Methods
Registry following the procedure specified in section 6.2.1 of Registry following the procedure specified in section 6.2.1 of
[RFC7800]: [RFC7800]:
o Confirmation Method Value: "osc" o Confirmation Method Value: "osc"
o Confirmation Method Description: OSCORE_Security_Context carrying o Confirmation Method Description: OSCORE_Security_Context carrying
the parameters for using OSCORE per-message security with implicit the parameters for using OSCORE per-message security with implicit
key confirmation key confirmation
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): Section 3.2.1 of [[this specification]] o Specification Document(s): Section 3.2.1 of [[this specification]]
9.5. Expert Review Instructions 9.7. Expert Review Instructions
The IANA registry established in this document is defined to use the The IANA registry established in this document is defined to use the
Expert Review registration policy. This section gives some general Expert Review registration policy. This section gives some general
guidelines for what the experts should be looking for, but they are guidelines for what the experts should be looking for, but they are
being designated as experts for a reason so they should be given being designated as experts for a reason so they should be given
substantial latitude. substantial latitude.
Expert reviewers should take into consideration the following points: Expert reviewers should take into consideration the following points:
o Point squatting should be discouraged. Reviewers are encouraged o Point squatting should be discouraged. Reviewers are encouraged
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