draft-ietf-oauth-spop-03.txt   draft-ietf-oauth-spop-04.txt 
OAuth Working Group N. Sakimura, Ed. OAuth Working Group N. Sakimura, Ed.
Internet-Draft Nomura Research Institute Internet-Draft Nomura Research Institute
Intended status: Standards Track J. Bradley Intended status: Standards Track J. Bradley
Expires: May 14, 2015 Ping Identity Expires: May 16, 2015 Ping Identity
N. Agarwal N. Agarwal
Google Google
November 12, 2014 November 12, 2014
Symmetric Proof of Possession for the OAuth Authorization Code Grant Symmetric Proof of Possession for the OAuth Authorization Code Grant
draft-ietf-oauth-spop-03 draft-ietf-oauth-spop-04
Abstract Abstract
The OAuth 2.0 public client utilizing Authorization Code Grant (RFC The OAuth 2.0 public client utilizing Authorization Code Grant (RFC
6749 - 4.1) is susceptible to the code interception attack. This 6749 - 4.1) is susceptible to the code interception attack. This
specification describes a mechanism that acts as a control against specification describes a mechanism that acts as a control against
this threat. this threat.
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 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
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This Internet-Draft will expire on May 14, 2015. This Internet-Draft will expire on May 16, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Protocol Flow . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Protocol Flow . . . . . . . . . . . . . . . . . . . . . . 3
2. Notational Conventions . . . . . . . . . . . . . . . . . . . . 3 2. Notational Conventions . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Client creates a code verifier . . . . . . . . . . . . . . 4 4.1. Client creates a code verifier . . . . . . . . . . . . . 5
4.2. Client creates the code challenge . . . . . . . . . . . . 5 4.2. Client creates the code challenge . . . . . . . . . . . . 5
4.3. Client sends the code challenge with the authorization 4.3. Client sends the code challenge with the authorization
request . . . . . . . . . . . . . . . . . . . . . . . . . 5 request . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.4. Server returns the code . . . . . . . . . . . . . . . . . 5 4.4. Server returns the code . . . . . . . . . . . . . . . . . 6
4.5. Client sends the code and the secret to the token endpoint 6 4.4.1. Error Response . . . . . . . . . . . . . . . . . . . 6
4.6. Server verifies code_verifier before returning the tokens 6 4.5. Client sends the code and the secret to the token
5. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 6 endpoint . . . . . . . . . . . . . . . . . . . . . . . . 7
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 4.6. Server verifies code_verifier before returning the tokens 7
6.1. OAuth Parameters Registry . . . . . . . . . . . . . . . . 7 5. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
7.1. Entropy of the code verifier . . . . . . . . . . . . . . . 7 6.1. OAuth Parameters Registry . . . . . . . . . . . . . . . . 8
7.2. Protection against eavesdroppers . . . . . . . . . . . . . 7 7. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7.3. Checking the Server support . . . . . . . . . . . . . . . 7 7.1. Entropy of the code verifier . . . . . . . . . . . . . . 8
7.4. OAuth security considerations . . . . . . . . . . . . . . 8 7.2. Protection against eavesdroppers . . . . . . . . . . . . 9
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8 7.3. Checking the Server support . . . . . . . . . . . . . . . 9
9. Revision History . . . . . . . . . . . . . . . . . . . . . . . 8 7.4. OAuth security considerations . . . . . . . . . . . . . . 9
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
10.1. Normative References . . . . . . . . . . . . . . . . . . 9 9. Revision History . . . . . . . . . . . . . . . . . . . . . . 10
10.2. Informative References . . . . . . . . . . . . . . . . . 9 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
Appendix A. Notes on implementing base64url encoding without paddi 10 10.1. Normative References . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 10.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Notes on implementing base64url encoding without
padding . . . . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction 1. Introduction
Public clients in OAuth 2.0 [RFC6749] are susceptible to the Public clients in OAuth 2.0 [RFC6749] are susceptible to the
authorization "code" interception attack. A malicious client authorization "code" interception attack. A malicious client
intercepts the authorization code returned from the authorization intercepts the authorization code returned from the authorization
endpoint and uses it to obtain the access token. This is possible on endpoint within communication path not protected by TLS, such as
a public client as there is no client secret associated for it to be inter-app communication, and uses it to obtain the access token.
sent to the token endpoint. This is especially true on Smartphone This is possible on a public client as there is no client secret
applications where the authorization code can be returned through associated for it to be sent to the token endpoint. This is
custom URL Schemes where the same scheme can be registered by especially true on Smartphone applications where the authorization
multiple applications. Under this scenario, the mitigation strategy code can be returned through custom URL Schemes where the same scheme
stated in section 4.4.1 of [RFC6819] does not work as they rely on can be registered by multiple applications. Under this scenario, the
per-client instance secret or per client instance redirect URI. mitigation strategy stated in section 4.4.1 of [RFC6819] does not
work as they rely on per-client instance secret or per client
instance redirect URI.
To mitigate this attack, this extension utilizes a dynamically To mitigate this attack, this extension utilizes a dynamically
created cryptographically random key called 'code verifier'. The code created cryptographically random key called 'code verifier'. The
verifier is created for every authorization request and its code verifier is created for every authorization request and its
transformed value, called 'code challenge', is sent to the transformed value, called 'code challenge', is sent to the
authorization server to obtain the authorization code. The authorization server to obtain the authorization code. The
authorization "code" obtained is then sent to the token endpoint with authorization "code" obtained is then sent to the token endpoint with
the 'code verifier' and the server compares it with the previously the 'code verifier' and the server compares it with the previously
received request code so that it can perform the proof of possession received request code so that it can perform the proof of possession
of the 'code verifier' by the client. This works as the mitigation of the 'code verifier' by the client. This works as the mitigation
since the attacker would not know this one-time key. since the attacker would not know this one-time key.
1.1. Protocol Flow 1.1. Protocol Flow
+--------+ +---------------+
| |--(A)-- Authorization Request --->| | +--------+ +---------------+
| | + t(code_verifier), t | Resource | | |--(A)-- Authorization Request --->| |
| | | Owner | | | + t(code_verifier), t | Resource |
| |<-(B)--- Authorization Grant -----| | | | | Owner |
| | +---------------+ | |<-(B)--- Authorization Grant -----| |
| Client | | | +---------------+
| | +---------------+ | Client |
| |--(C)--- Access Token Request --->| | | | +---------------+
| | + code_verifier | Authorization | | |--(C)--- Access Token Request --->| |
| | | Server | | | + code_verifier | Authorization |
| |<-(D)------ Access Token ---------| | | | | Server |
+--------+ +---------------+ | |<-(D)------ Access Token ---------| |
+--------+ +---------------+
Figure 1: Abstract Protocol Flow
This specification adds additional parameters to the OAuth 2.0 This specification adds additional parameters to the OAuth 2.0
Authorization and Access Token Requests, shown in abstract form in Authorization and Access Token Requests, shown in abstract form in
Figure 1. Figure 1.
A. The client creates and records a secret named the "code_verifier", A. The client creates and records a secret named the "code_verifier",
and derives a transformed version "t(code_verifier)" (referred to and derives a transformed version "t(code_verifier)" (referred to
as the "code_challenge") which is sent in the OAuth 2.0 as the "code_challenge") which is sent in the OAuth 2.0
Authorization Request, along with the transformation method "t". Authorization Request, along with the transformation method "t".
B. The resource owner responds as usual, but records B. The resource owner responds as usual, but records
"t(code_verifier)" and the transformation method. "t(code_verifier)" and the transformation method.
C. The client then sends the code to the Access Token Request as C. The client then sends the code to the Access Token Request as
usual, but includes the "code_verifier" secret generated at (A). usual, but includes the "code_verifier" secret generated at (A).
D. The authorization server transforms "code_verifier" and compares D. The authorization server transforms "code_verifier" and compares
it to "t(code_verifier)" from (B). Access is denied if they are it to "t(code_verifier)" from (B). Access is denied if they are
not equal. not equal.
An attacker who intercepts the Authorization Grant at (B) is unable An attacker who intercepts the Authorization Grant at (B) is unable
to redeem it for an Access Token, as they are not in possession of to redeem it for an Access Token, as they are not in possession of
the "code_verifier" secret. the "code_verifier" secret.
2. Notational Conventions 2. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
skipping to change at page 4, line 24 skipping to change at page 4, line 46
ASCII(STRING) denotes the octets of the ASCII [US-ASCII] ASCII(STRING) denotes the octets of the ASCII [US-ASCII]
representation of STRING. representation of STRING.
The concatenation of two values A and B is denoted as A || B. The concatenation of two values A and B is denoted as A || B.
3. Terminology 3. Terminology
In addition to the terms defined in OAuth 2.0 [RFC6749], this In addition to the terms defined in OAuth 2.0 [RFC6749], this
specification defines the following terms: specification defines the following terms:
code verifier A cryptographically random string that is used to code verifier A cryptographically random string that is used to
correlate the authorization request to the token request. correlate the authorization request to the token request.
code challenge A challenge derived from the code verifier that is code challenge A challenge derived from the code verifier that is
sent in the authorization request, to be verified against later. sent in the authorization request, to be verified against later.
Base64url Encoding Base64 encoding using the URL- and filename-safe Base64url Encoding Base64 encoding using the URL- and filename-safe
character set defined in Section 5 of RFC 4648 [RFC4648], with all character set defined in Section 5 of RFC 4648 [RFC4648], with all
trailing '=' characters omitted (as permitted by Section 3.2) and trailing '=' characters omitted (as permitted by Section 3.2) and
without the inclusion of any line breaks, whitespace, or other without the inclusion of any line breaks, whitespace, or other
additional characters. (See Appendix Appendix A for notes on additional characters. (See Appendix A for notes on implementing
implementing base64url encoding without padding.) base64url encoding without padding.)
4. Protocol 4. Protocol
4.1. Client creates a code verifier 4.1. Client creates a code verifier
The client first creates a code verifier, "code_verifier", for each The client first creates a code verifier, "code_verifier", for each
OAuth 2.0 [RFC6749] Authorization Request, in the following manner: OAuth 2.0 [RFC6749] Authorization Request, in the following manner:
code_verifier = high entropy cryptographic random [US-ASCII] sequence code_verifier = high entropy cryptographic random [US-ASCII] sequence
using the url and filename safe Alphabet [A-Z] / [a-z] / [0-9] / "-" using the url and filename safe Alphabet [A-Z] / [a-z] / [0-9] / "-"
/ "_" from Sec 5 of RFC 4648 [RFC4648], with length less than 128 / "_" from Sec 5 of RFC 4648 [RFC4648], with length less than 128
characters. characters.
ABNF for "code_verifier" is as follows. ABNF for "code_verifier" is as follows.
code_verifier = 42*128unreserved code_verifier = 42*128unreserved
unreserved = [A-Z] / [a-z] / [0-9] / "-" / "_" unreserved = [A-Z] / [a-z] / [0-9] / "-" / "_"
NOTE: code verifier SHOULD have enough entropy to make it impractical NOTE: code verifier SHOULD have enough entropy to make it impractical
to guess the value. It is RECOMMENDED that the output of a suitable to guess the value. It is RECOMMENDED that the output of a suitable
random number generator be used to create a 32-octet sequence. The random number generator be used to create a 32-octet sequence. The
Octet sequence is then BASE64URL encoded to produce a 42-octet URL Octet sequence is then BASE64URL encoded to produce a 42-octet URL
safe string to use as the code verifier. safe string to use as the code verifier.
4.2. Client creates the code challenge 4.2. Client creates the code challenge
The client then creates a code challenge, "code_challenge", derived The client then creates a code challenge, "code_challenge", derived
from the "code_verifier" by using one of the following from the "code_verifier" by using one of the following
transformations on the "code_verifier": transformations on the "code_verifier":
plain "code_challenge" = "code_verifier" plain "code_challenge" = "code_verifier"
S256 "code_challenge" = BASE64URL(SHA256("code_verifier")) S256 "code_challenge" = BASE64URL(SHA256("code_verifier"))
It is RECOMMENDED to use the S256 transformation when possible. It is RECOMMENDED to use the S256 transformation when possible.
ABNF for "code_challenge" is as follows. ABNF for "code_challenge" is as follows.
code_challenge = 42*128unreserved code_challenge = 42*128unreserved
unreserved = [A-Z] / [a-z] / [0-9] / "-" / "_" unreserved = [A-Z] / [a-z] / [0-9] / "-" / "_"
4.3. Client sends the code challenge with the authorization request 4.3. Client sends the code challenge with the authorization request
The client sends the code challenge as part of the OAuth 2.0 The client sends the code challenge as part of the OAuth 2.0
[RFC6749] Authorization Request (Section 4.1.1.) using the following [RFC6749] Authorization Request (Section 4.1.1.) using the following
additional parameters: additional parameters:
code_challenge REQUIRED. Code challenge. code_challenge REQUIRED. Code challenge.
code_challenge_method OPTIONAL, defaults to "plain". Code verifier code_challenge_method OPTIONAL, defaults to "plain". Code verifier
transformation method, "S256" or "plain". transformation method, "S256" or "plain".
4.4. Server returns the code 4.4. Server returns the code
When the server issues the "code" in the Authorization Response, it When the server issues the "code" in the Authorization Response, it
MUST associate the "code_challenge" and "code_challenge_method" MUST associate the "code_challenge" and "code_challenge_method"
values with the "code" so it can be verified later. values with the "code" so it can be verified later.
Typically, the "code_challenge" and "code_challenge_method" values Typically, the "code_challenge" and "code_challenge_method" values
are stored in encrypted form in the "code" itself, but could are stored in encrypted form in the "code" itself, but could
alternatively be stored on the server, associated with the code. The alternatively be stored on the server, associated with the code. The
server MUST NOT include the "code_challenge" value in client requests server MUST NOT include the "code_challenge" value in client requests
in a form that other entities can extract. in a form that other entities can extract.
The exact method that the server uses to associate the The exact method that the server uses to associate the
"code_challenge" with the issued "code" is out of scope for this "code_challenge" with the issued "code" is out of scope for this
specification. specification.
4.4.1. Error Response
If the server requires SPOP, and the client does not send the
"code_challenge" in the request, the authorization endpoint MUST
return the authorization error response as described in 4.1.2.1. of
OAuth 2.0 [RFC6749] with "error" value set to "invalid_request" and
"error_description" or "error_uri" whose content explaining the
nature of error.
If the server supporting SPOP only supports "S256", and the client
requests plain transformation, the authorization endpoint MUST return
the authorization error response as described in 4.1.2.1. of OAuth
2.0 [RFC6749] with "error" value set to "unsupported_spop_transform".
The "error_description" or the response of "error_uri" SHOULD explain
the nature of error, e.g., transform algorithm not supported.
If the client is capable of using "S256", it MUST use "S256", as
"S256" is MTI on the server. Clients MAY use plain only if they
cannot support "S256" for some technical reason and knows that the
server supports "plain".
4.5. Client sends the code and the secret to the token endpoint 4.5. Client sends the code and the secret to the token endpoint
Upon receipt of the "code", the client sends the Access Token Request Upon receipt of the "code", the client sends the Access Token Request
to the token endpoint. In addition to the parameters defined in to the token endpoint. In addition to the parameters defined in
OAuth 2.0 [RFC6749] Access Token Request (Section 4.1.3.), it sends OAuth 2.0 [RFC6749] Access Token Request (Section 4.1.3.), it sends
the following parameter: the following parameter:
code_verifier REQUIRED. Code verifier code_verifier REQUIRED. Code verifier
4.6. Server verifies code_verifier before returning the tokens 4.6. Server verifies code_verifier before returning the tokens
Upon receipt of the request at the Access Token endpoint, the server Upon receipt of the request at the Access Token endpoint, the server
verifies it by calculating the code challenge from received verifies it by calculating the code challenge from received
"code_verifier" and comparing it with the previously associated "code_verifier" and comparing it with the previously associated
"code_challenge", after first transforming it according to the "code_challenge", after first transforming it according to the
"code_challenge_method" method specified by the client. "code_challenge_method" method specified by the client.
If the "code_challenge_method" from 3.2 was "S256", the received If the "code_challenge_method" from 3.2 was "S256", the received
"code_verifier" is first hashed with SHA-256 then compared to the "code_verifier" is first hashed with SHA-256 then compared to the
base64url decoded "code_challenge". i.e., base64url decoded "code_challenge". i.e.,
SHA256("code_verifier" ) == BASE64URL-DECODE("code_challenge"). SHA256("code_verifier" ) == BASE64URL-DECODE("code_challenge").
If the "code_challenge_method" from 3.2 was "none", they are compared If the "code_challenge_method" from 3.2 was "none", they are compared
directly. i.e., directly. i.e.,
"code_challenge" == "code_verifier". "code_challenge" == "code_verifier".
If the values are equal, the Access Token endpoint MUST continue If the values are equal, the Access Token endpoint MUST continue
processing as normal (as defined by OAuth 2.0 [RFC6749]). If the processing as normal (as defined by OAuth 2.0 [RFC6749]). If the
values are not equal, an error response indicating "invalid_grant" as values are not equal, an error response indicating "invalid_grant" as
described in section 5.2 of OAuth 2.0 [RFC6749] MUST be returned. described in section 5.2 of OAuth 2.0 [RFC6749] MUST be returned.
5. Compatibility 5. Compatibility
Server implementations of this specification MAY accept OAuth2.0 Server implementations of this specification MAY accept OAuth2.0
Clients that do not implement this extension. If the "code_verifier" Clients that do not implement this extension. If the "code_verifier"
is not received from the client in the Authorization Request, servers is not received from the client in the Authorization Request, servers
supporting backwards compatibility SHOULD revert to a normal OAuth supporting backwards compatibility SHOULD revert to a normal OAuth
2.0 [RFC6749] protocol. 2.0 [RFC6749] protocol.
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The security model relies on the fact that the code verifier is not The security model relies on the fact that the code verifier is not
learned or guessed by the attacker. It is vitally important to learned or guessed by the attacker. It is vitally important to
adhere to this principle. As such, the code verifier has to be adhere to this principle. As such, the code verifier has to be
created in such a manner that it is cryptographically random and has created in such a manner that it is cryptographically random and has
high entropy that it is not practical for the attacker to guess. It high entropy that it is not practical for the attacker to guess. It
is RECOMMENDED that the output of a suitable random number generator is RECOMMENDED that the output of a suitable random number generator
be used to create a 32-octet sequence. be used to create a 32-octet sequence.
7.2. Protection against eavesdroppers 7.2. Protection against eavesdroppers
Unless there is a compelling reason, implementations SHOULD use Clients MUST NOT try down grading the algorithm after trying "S256"
"S256" method to protect against eavesdroppers intercepting the method. If the server is SPOP compliant, then "S256" method works.
"code_challenge". If the no transformation algorithm, which is the If the server does not support SPOP, it does not generate error.
default algorithm, is used, the client SHOULD make sure that the Only the time that the server returns that it does not support "S256"
authorization request is adequately protected from an eavesdropper. is there is a MITM trying the algorithm downgrade attack.
If "code_challenge" is to be returned inside authorization "code", it
has to be encrypted in such a manner that only the server can decrypt "S256" method protects against eavesdroppers observing or
and extract it. intercepting the "code_challenge". If the "plain" method is used,
there is a chance that it will be observed by the attacker on the
device. The use of "S256" protects against it.
If "code_challenge" is to be returned inside authorization "code" to
achieve a stateless server, it has to be encrypted in such a manner
that only the server can decrypt and extract it.
7.3. Checking the Server support 7.3. Checking the Server support
Before starting the authorization process, the client SHOULD check if Before starting the authorization process, the client SHOULD check if
the server supports this specification. Confirmation of the server the server supports this specification. Confirmation of the server
support may be obtained out-of-band or through some other mechanisms support may be obtained out-of-band or through some other mechanisms
such as the discovery document in OpenID Connect Discovery such as the discovery document in OpenID Connect Discovery
[OpenID.Discovery]. The exact mechanism on how the client obtains [OpenID.Discovery]. The exact mechanism on how the client obtains
this information, or the action it takes as a result is out of scope this information, or the action it takes as a result is out of scope
of this specification. of this specification.
7.4. OAuth security considerations 7.4. OAuth security considerations
skipping to change at page 8, line 32 skipping to change at page 10, line 4
o Naveen Agarwal, Google o Naveen Agarwal, Google
o Dirk Balfanz, Google o Dirk Balfanz, Google
o Sergey Beryozkin o Sergey Beryozkin
o John Bradley, Ping Identity o John Bradley, Ping Identity
o Brian Campbell, Ping Identity o Brian Campbell, Ping Identity
o William Denniss, Google o William Denniss, Google
o Eduardo Gueiros, Jive Communications o Eduardo Gueiros, Jive Communications
o Phil Hunt, Oracle o Phil Hunt, Oracle
o Ryo Ito, mixi o Ryo Ito, mixi
o Michael B. Jones, Microsoft o Michael B. Jones, Microsoft
o Torsten Lodderstedt, Deutsche Telekom o Torsten Lodderstedt, Deutsche Telekom
o Breno de Medeiros, Google o Breno de Medeiros, Google
o Prateek Mishra, Oracle o Prateek Mishra, Oracle
o Anthony Nadalin, Microsoft o Anthony Nadalin, Microsoft
o Axel Nenker, Deutsche Telekom o Axel Nenker, Deutsche Telekom
o Nat Sakimura, Nomura Research Institute o Nat Sakimura, Nomura Research Institute
9. Revision History 9. Revision History
-04
o Added error response to authorization response.
-03 -03
o Added an abstract protocol diagram and explanation o Added an abstract protocol diagram and explanation
-02 -02
o Copy edits o Copy edits
-01 -01
skipping to change at page 10, line 4 skipping to change at page 11, line 36
6749, October 2012. 6749, October 2012.
[US-ASCII] [US-ASCII]
American National Standards Institute, "Coded Character American National Standards Institute, "Coded Character
Set -- 7-bit American Standard Code for Information Set -- 7-bit American Standard Code for Information
Interchange", ANSI X3.4, 1986. Interchange", ANSI X3.4, 1986.
10.2. Informative References 10.2. Informative References
[OpenID.Discovery] [OpenID.Discovery]
Sakimura, N., Bradley, J., Jones, M.B. and E. Jay, "OpenID Sakimura, N., Bradley, J., Jones, M., and E. Jay, "OpenID
Connect Discovery 1.0", February 2014. Connect Discovery 1.0", February 2014.
[RFC6819] Lodderstedt, T., McGloin, M. and P. Hunt, "OAuth 2.0 [RFC6819] Lodderstedt, T., McGloin, M., and P. Hunt, "OAuth 2.0
Threat Model and Security Considerations", RFC 6819, Threat Model and Security Considerations", RFC 6819,
January 2013. January 2013.
Appendix A. Notes on implementing base64url encoding without padding Appendix A. Notes on implementing base64url encoding without padding
This appendix describes how to implement base64url encoding and This appendix describes how to implement base64url encoding and
decoding functions without padding based upon standard base64 decoding functions without padding based upon standard base64
encoding and decoding functions that do use padding. encoding and decoding functions that do use padding.
To be concrete, example C# code implementing these functions is shown To be concrete, example C# code implementing these functions is shown
skipping to change at page 11, line 10 skipping to change at page 13, line 4
An example correspondence between unencoded and encoded values An example correspondence between unencoded and encoded values
follows. The octet sequence below encodes into the string below, follows. The octet sequence below encodes into the string below,
which when decoded, reproduces the octet sequence. which when decoded, reproduces the octet sequence.
3 236 255 224 193 3 236 255 224 193
A-z_4ME A-z_4ME
Authors' Addresses Authors' Addresses
Nat Sakimura (editor)
Nat Sakimura, editor
Nomura Research Institute Nomura Research Institute
1-6-5 Marunouchi, Marunouchi Kitaguchi Bldg. 1-6-5 Marunouchi, Marunouchi Kitaguchi Bldg.
Chiyoda-ku, Tokyo 100-0005 Chiyoda-ku, Tokyo 100-0005
Japan Japan
Phone: +81-3-5533-2111 Phone: +81-3-5533-2111
Email: n-sakimura@nri.co.jp Email: n-sakimura@nri.co.jp
URI: http://nat.sakimura.org/ URI: http://nat.sakimura.org/
John Bradley John Bradley
Ping Identity Ping Identity
Casilla 177, Sucursal Talagante Casilla 177, Sucursal Talagante
Talagante, RM Talagante, RM
Chile Chile
Phone: +44 20 8133 3718 Phone: +44 20 8133 3718
Email: ve7jtb@ve7jtb.com Email: ve7jtb@ve7jtb.com
URI: http://www.thread-safe.com/ URI: http://www.thread-safe.com/
Naveen Agarwal Naveen Agarwal
Google Google
1600 Amphitheatre Pkwy 1600 Amphitheatre Pkwy
Mountain View, CA 94043 Mountain View, CA 94043
USA USA
Phone: +1 650-253-0000 Phone: +1 650-253-0000
Email: naa@google.com Email: naa@google.com
URI: http://google.com/ URI: http://google.com/
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