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JOSE Working Group M. Jones
Internet-Draft Microsoft
Intended status: Standards Track J. Bradley
Expires: January 12, 2014 Ping Identity
N. Sakimura
NRI
July 11, 2013
JSON Web Signature (JWS)
draft-ietf-jose-json-web-signature-12
Abstract
JSON Web Signature (JWS) is a means of representing content secured
with digital signatures or Message Authentication Codes (MACs) using
JavaScript Object Notation (JSON) based data structures.
Cryptographic algorithms and identifiers for use with this
specification are described in the separate JSON Web Algorithms (JWA)
specification. Related encryption capabilities are described in the
separate JSON Web Encryption (JWE) specification.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 12, 2014.
Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Notational Conventions . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. JSON Web Signature (JWS) Overview . . . . . . . . . . . . . . 6
3.1. Example JWS . . . . . . . . . . . . . . . . . . . . . . . 6
4. JWS Header . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Reserved Header Parameter Names . . . . . . . . . . . . . 8
4.1.1. "alg" (Algorithm) Header Parameter . . . . . . . . . . 8
4.1.2. "jku" (JWK Set URL) Header Parameter . . . . . . . . . 9
4.1.3. "jwk" (JSON Web Key) Header Parameter . . . . . . . . 9
4.1.4. "x5u" (X.509 URL) Header Parameter . . . . . . . . . . 9
4.1.5. "x5t" (X.509 Certificate Thumbprint) Header
Parameter . . . . . . . . . . . . . . . . . . . . . . 10
4.1.6. "x5c" (X.509 Certificate Chain) Header Parameter . . . 10
4.1.7. "kid" (Key ID) Header Parameter . . . . . . . . . . . 10
4.1.8. "typ" (Type) Header Parameter . . . . . . . . . . . . 11
4.1.9. "cty" (Content Type) Header Parameter . . . . . . . . 11
4.1.10. "crit" (Critical) Header Parameter . . . . . . . . . . 11
4.2. Public Header Parameter Names . . . . . . . . . . . . . . 12
4.3. Private Header Parameter Names . . . . . . . . . . . . . . 12
5. Producing and Consuming JWSs . . . . . . . . . . . . . . . . . 12
5.1. Message Signing or MACing . . . . . . . . . . . . . . . . 12
5.2. Message Signature or MAC Validation . . . . . . . . . . . 13
5.3. String Comparison Rules . . . . . . . . . . . . . . . . . 15
6. Key Identification . . . . . . . . . . . . . . . . . . . . . . 15
7. Serializations . . . . . . . . . . . . . . . . . . . . . . . . 16
7.1. JWS Compact Serialization . . . . . . . . . . . . . . . . 16
7.2. JWS JSON Serialization . . . . . . . . . . . . . . . . . . 16
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
8.1. JSON Web Signature and Encryption Header Parameters
Registry . . . . . . . . . . . . . . . . . . . . . . . . . 19
8.1.1. Registration Template . . . . . . . . . . . . . . . . 19
8.1.2. Initial Registry Contents . . . . . . . . . . . . . . 19
8.2. JSON Web Signature and Encryption Type Values Registry . . 21
8.2.1. Registration Template . . . . . . . . . . . . . . . . 21
8.2.2. Initial Registry Contents . . . . . . . . . . . . . . 21
8.3. Media Type Registration . . . . . . . . . . . . . . . . . 22
8.3.1. Registry Contents . . . . . . . . . . . . . . . . . . 22
9. Security Considerations . . . . . . . . . . . . . . . . . . . 23
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9.1. Cryptographic Security Considerations . . . . . . . . . . 23
9.2. JSON Security Considerations . . . . . . . . . . . . . . . 24
9.3. Unicode Comparison Security Considerations . . . . . . . . 25
9.4. TLS Requirements . . . . . . . . . . . . . . . . . . . . . 25
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 25
10.1. Normative References . . . . . . . . . . . . . . . . . . . 25
10.2. Informative References . . . . . . . . . . . . . . . . . . 27
Appendix A. JWS Examples . . . . . . . . . . . . . . . . . . . . 28
A.1. Example JWS using HMAC SHA-256 . . . . . . . . . . . . . . 28
A.1.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 28
A.1.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 30
A.1.3. Validating . . . . . . . . . . . . . . . . . . . . . . 30
A.2. Example JWS using RSASSA-PKCS-v1_5 SHA-256 . . . . . . . . 30
A.2.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 31
A.2.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 33
A.2.3. Validating . . . . . . . . . . . . . . . . . . . . . . 33
A.3. Example JWS using ECDSA P-256 SHA-256 . . . . . . . . . . 34
A.3.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 34
A.3.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 36
A.3.3. Validating . . . . . . . . . . . . . . . . . . . . . . 36
A.4. Example JWS using ECDSA P-521 SHA-512 . . . . . . . . . . 36
A.4.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 36
A.4.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 38
A.4.3. Validating . . . . . . . . . . . . . . . . . . . . . . 39
A.5. Example Plaintext JWS . . . . . . . . . . . . . . . . . . 39
A.6. Example JWS Using JWS JSON Serialization . . . . . . . . . 40
A.6.1. JWS Protected Header . . . . . . . . . . . . . . . . . 40
A.6.2. JWS Per-Signature Unprotected Headers . . . . . . . . 40
A.6.3. Complete JWS Header Values . . . . . . . . . . . . . . 41
A.6.4. Complete JWS JSON Serialization Representation . . . . 41
A.6.5. RSA Key Used for Second Signature . . . . . . . . . . 42
Appendix B. "x5c" (X.509 Certificate Chain) Example . . . . . . . 42
Appendix C. Notes on implementing base64url encoding without
padding . . . . . . . . . . . . . . . . . . . . . . . 44
Appendix D. Negative Test Case for "crit" Header Parameter . . . 45
Appendix E. Acknowledgements . . . . . . . . . . . . . . . . . . 45
Appendix F. Document History . . . . . . . . . . . . . . . . . . 46
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 51
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1. Introduction
JSON Web Signature (JWS) is a means of representing content secured
with digital signatures or Message Authentication Codes (MACs) using
JavaScript Object Notation (JSON) [RFC4627] based data structures.
The JWS cryptographic mechanisms provide integrity protection for
arbitrary sequences of octets.
Two closely related representations for JWS objects are defined. The
JWS Compact Serialization is a compact, URL-safe representation
intended for space constrained environments such as HTTP
Authorization headers and URI query parameters. The JWS JSON
Serialization represents JWS objects as JSON objects and enables
multiple signatures and/or MACs to be applied to the same content.
Both share the same cryptographic underpinnings.
Cryptographic algorithms and identifiers for use with this
specification are described in the separate JSON Web Algorithms (JWA)
[JWA] specification. Related encryption capabilities are described
in the separate JSON Web Encryption (JWE) [JWE] specification.
1.1. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in Key words for use in
RFCs to Indicate Requirement Levels [RFC2119].
2. Terminology
JSON Web Signature (JWS) A data structure representing a digitally
signed or MACed message. The structure represents three values:
the JWS Header, the JWS Payload, and the JWS Signature.
JSON Text Object A UTF-8 [RFC3629] encoded text string representing
a JSON object; the syntax of JSON objects is defined in Section
2.2 of [RFC4627].
JWS Header A JSON Text Object (or JSON Text Objects, when using the
JWS JSON Serialization) that describes the digital signature or
MAC operation applied to create the JWS Signature value. The
members of the JWS Header object(s) are Header Parameters.
JWS Payload The sequence of octets to be secured -- a.k.a., the
message. The payload can contain an arbitrary sequence of octets.
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JWS Signature A sequence of octets containing the cryptographic
material that ensures the integrity of the JWS Protected Header
and the JWS Payload. The JWS Signature value is a digital
signature or MAC value calculated over the JWS Signing Input using
the parameters specified in the JWS Header.
JWS Protected Header A JSON Text Object that contains the portion of
the JWS Header that is integrity protected. For the JWS Compact
Serialization, this comprises the entire JWS Header. For the JWS
JSON Serialization, this is one component of the JWS Header.
Header Parameter A name/value pair that is member of the JWS Header.
Header Parameter Name The name of a member of the JWS Header.
Header Parameter Value The value of a member of the JWS Header.
Base64url Encoding The URL- and filename-safe Base64 encoding
described in RFC 4648 [RFC4648], Section 5, with the (non URL-
safe) '=' padding characters omitted, as permitted by Section 3.2.
(See Appendix C for notes on implementing base64url encoding
without padding.)
Encoded JWS Header Base64url encoding of the JWS Protected Header.
Encoded JWS Payload Base64url encoding of the JWS Payload.
Encoded JWS Signature Base64url encoding of the JWS Signature.
JWS Signing Input The concatenation of the Encoded JWS Header, a
period ('.') character, and the Encoded JWS Payload.
JWS Compact Serialization A representation of the JWS as the
concatenation of the Encoded JWS Header, the Encoded JWS Payload,
and the Encoded JWS Signature in that order, with the three
strings being separated by two period ('.') characters. This
representation is compact and URL-safe.
JWS JSON Serialization A representation of the JWS as a JSON
structure containing JWS Header, Encoded JWS Payload, and Encoded
JWS Signature values. Unlike the JWS Compact Serialization, the
JWS JSON Serialization enables multiple digital signatures and/or
MACs to be applied to the same content. This representation is
neither compact nor URL-safe.
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Collision Resistant Namespace A namespace that allows names to be
allocated in a manner such that they are highly unlikely to
collide with other names. For instance, collision resistance can
be achieved through administrative delegation of portions of the
namespace or through use of collision-resistant name allocation
functions. Examples of Collision Resistant Namespaces include:
Domain Names, Object Identifiers (OIDs) as defined in the ITU-T
X.660 and X.670 Recommendation series, and Universally Unique
IDentifiers (UUIDs) [RFC4122]. When using an administratively
delegated namespace, the definer of a name needs to take
reasonable precautions to ensure they are in control of the
portion of the namespace they use to define the name.
StringOrURI A JSON string value, with the additional requirement
that while arbitrary string values MAY be used, any value
containing a ":" character MUST be a URI [RFC3986]. StringOrURI
values are compared as case-sensitive strings with no
transformations or canonicalizations applied.
3. JSON Web Signature (JWS) Overview
JWS represents digitally signed or MACed content using JSON data
structures and base64url encoding. Three values are represented in a
JWS: the JWS Header, the JWS Payload, and the JWS Signature. In the
Compact Serialization, the three values are base64url-encoded for
transmission, and represented as the concatenation of the encoded
strings in that order, with the three strings being separated by two
period ('.') characters. A JSON Serialization for this information
is also defined in Section 7.2.
The JWS Header describes the signature or MAC method and parameters
employed. The JWS Payload is the message content to be secured. The
JWS Signature ensures the integrity of both the JWS Protected Header
and the JWS Payload.
3.1. Example JWS
The following example JWS Header declares that the encoded object is
a JSON Web Token (JWT) [JWT] and the JWS Header and the JWS Payload
are secured using the HMAC SHA-256 algorithm:
{"typ":"JWT",
"alg":"HS256"}
Base64url encoding the octets of the UTF-8 representation of the JWS
Header yields this Encoded JWS Header value:
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eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9
The following is an example of a JSON object that can be used as a
JWS Payload. (Note that the payload can be any content, and need not
be a representation of a JSON object.)
{"iss":"joe",
"exp":1300819380,
"http://example.com/is_root":true}
The following octet sequence, which is the UTF-8 representation of
the JSON object above, is the JWS Payload:
[123, 34, 105, 115, 115, 34, 58, 34, 106, 111, 101, 34, 44, 13, 10,
32, 34, 101, 120, 112, 34, 58, 49, 51, 48, 48, 56, 49, 57, 51, 56,
48, 44, 13, 10, 32, 34, 104, 116, 116, 112, 58, 47, 47, 101, 120, 97,
109, 112, 108, 101, 46, 99, 111, 109, 47, 105, 115, 95, 114, 111,
111, 116, 34, 58, 116, 114, 117, 101, 125]
Base64url encoding the JWS Payload yields this Encoded JWS Payload
(with line breaks for display purposes only):
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
Computing the HMAC of the octets of the ASCII [USASCII]
representation of the JWS Signing Input (the concatenation of the
Encoded JWS Header, a period ('.') character, and the Encoded JWS
Payload) with the HMAC SHA-256 algorithm using the key specified in
Appendix A.1 and base64url encoding the result yields this Encoded
JWS Signature value:
dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk
Concatenating these values in the order Header.Payload.Signature with
period ('.') characters between the parts yields this complete JWS
representation using the JWS Compact Serialization (with line breaks
for display purposes only):
eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
.
dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk
This computation is illustrated in more detail in Appendix A.1. See
Appendix A for additional examples.
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4. JWS Header
The members of the JSON object(s) representing the JWS Header
describe the digital signature or MAC applied to the Encoded JWS
Header and the Encoded JWS Payload and optionally additional
properties of the JWS. The Header Parameter Names within the JWS
Header MUST be unique; receipients MUST either reject JWSs with
duplicate Header Parameter Names or use a JSON parser that returns
only the lexically last duplicate member name, as specified in
Section 15.12 (The JSON Object) of ECMAScript 5.1 [ECMAScript].
Implementations are required to understand the specific header
parameters defined by this specification that are designated as "MUST
be understood" and process them in the manner defined in this
specification. All other header parameters defined by this
specification that are not so designated MUST be ignored when not
understood. Unless listed as a critical header parameter, per
Section 4.1.10, all header parameters not defined by this
specification MUST be ignored when not understood.
There are three classes of Header Parameter Names: Reserved Header
Parameter Names, Public Header Parameter Names, and Private Header
Parameter Names.
4.1. Reserved Header Parameter Names
The following Header Parameter Names are reserved with meanings as
defined below. All the names are short because a core goal of this
specification is for the resulting representations using the JWS
Compact Serialization to be compact.
Additional reserved Header Parameter Names can be defined via the
IANA JSON Web Signature and Encryption Header Parameters registry
Section 8.1. As indicated by the common registry, JWSs and JWEs
share a common header parameter space; when a parameter is used by
both specifications, its usage must be compatible between the
specifications.
4.1.1. "alg" (Algorithm) Header Parameter
The "alg" (algorithm) header parameter identifies a cryptographic
algorithm used to secure the JWS. The recipient MUST reject the JWS
if the "alg" value does not represent a supported algorithm, or if
there is not a key for use with that algorithm associated with the
party that digitally signed or MACed the content. "alg" values SHOULD
either be registered in the IANA JSON Web Signature and Encryption
Algorithms registry [JWA] or be a value that contains a Collision
Resistant Namespace. The "alg" value is a case sensitive string
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containing a StringOrURI value. Use of this header parameter is
REQUIRED. This header parameter MUST be understood by
implementations.
A list of defined "alg" values can be found in the IANA JSON Web
Signature and Encryption Algorithms registry [JWA]; the initial
contents of this registry are the values defined in Section 3.1 of
the JSON Web Algorithms (JWA) [JWA] specification.
4.1.2. "jku" (JWK Set URL) Header Parameter
The "jku" (JWK Set URL) header parameter is a URI [RFC3986] that
refers to a resource for a set of JSON-encoded public keys, one of
which corresponds to the key used to digitally sign the JWS. The
keys MUST be encoded as a JSON Web Key Set (JWK Set) [JWK]. The
protocol used to acquire the resource MUST provide integrity
protection; an HTTP GET request to retrieve the JWK Set MUST use TLS
[RFC2818] [RFC5246]; the identity of the server MUST be validated, as
per Section 3.1 of HTTP Over TLS [RFC2818]. Use of this header
parameter is OPTIONAL.
4.1.3. "jwk" (JSON Web Key) Header Parameter
The "jwk" (JSON Web Key) header parameter is the public key that
corresponds to the key used to digitally sign the JWS. This key is
represented as a JSON Web Key [JWK]. Use of this header parameter is
OPTIONAL.
4.1.4. "x5u" (X.509 URL) Header Parameter
The "x5u" (X.509 URL) header parameter is a URI [RFC3986] that refers
to a resource for the X.509 public key certificate or certificate
chain [RFC5280] corresponding to the key used to digitally sign the
JWS. The identified resource MUST provide a representation of the
certificate or certificate chain that conforms to RFC 5280 [RFC5280]
in PEM encoded form [RFC1421]. The certificate containing the public
key corresponding to the key used to digitally sign the JWS MUST be
the first certificate. This MAY be followed by additional
certificates, with each subsequent certificate being the one used to
certify the previous one. The protocol used to acquire the resource
MUST provide integrity protection; an HTTP GET request to retrieve
the certificate MUST use TLS [RFC2818] [RFC5246]; the identity of the
server MUST be validated, as per Section 3.1 of HTTP Over TLS
[RFC2818]. Use of this header parameter is OPTIONAL.
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4.1.5. "x5t" (X.509 Certificate Thumbprint) Header Parameter
The "x5t" (X.509 Certificate Thumbprint) header parameter is a
base64url encoded SHA-1 thumbprint (a.k.a. digest) of the DER
encoding of the X.509 certificate [RFC5280] corresponding to the key
used to digitally sign the JWS. Use of this header parameter is
OPTIONAL.
If, in the future, certificate thumbprints need to be computed using
hash functions other than SHA-1, it is suggested that additional
related header parameters be defined for that purpose. For example,
it is suggested that a new "x5t#S256" (X.509 Certificate Thumbprint
using SHA-256) header parameter could be defined by registering it in
the IANA JSON Web Signature and Encryption Header Parameters registry
Section 8.1.
4.1.6. "x5c" (X.509 Certificate Chain) Header Parameter
The "x5c" (X.509 Certificate Chain) header parameter contains the
X.509 public key certificate or certificate chain [RFC5280]
corresponding to the key used to digitally sign the JWS. The
certificate or certificate chain is represented as a JSON array of
certificate value strings. Each string in the array is a base64
encoded ([RFC4648] Section 4 -- not base64url encoded) DER
[ITU.X690.1994] PKIX certificate value. The certificate containing
the public key corresponding to the key used to digitally sign the
JWS MUST be the first certificate. This MAY be followed by
additional certificates, with each subsequent certificate being the
one used to certify the previous one. The recipient MUST verify the
certificate chain according to [RFC5280] and reject the JWS if any
validation failure occurs. Use of this header parameter is OPTIONAL.
See Appendix B for an example "x5c" value.
4.1.7. "kid" (Key ID) Header Parameter
The "kid" (key ID) header parameter is a hint indicating which key
was used to secure the JWS. This parameter allows originators to
explicitly signal a change of key to recipients. Should the
recipient be unable to locate a key corresponding to the "kid" value,
they SHOULD treat that condition as an error. The interpretation of
the "kid" value is unspecified. Its value MUST be a string. Use of
this header parameter is OPTIONAL.
When used with a JWK, the "kid" value can be used to match a JWK
"kid" parameter value.
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4.1.8. "typ" (Type) Header Parameter
The "typ" (type) header parameter MAY be used to declare the type of
this complete JWS object in an application-specific manner in
contexts where this is useful to the application. This parameter has
no effect upon the JWS processing. The type value "JOSE" MAY be used
to indicate that this object is a JWS or JWE using the JWS Compact
Serialization or the JWE Compact Serialization. The type value
"JOSE+JSON" MAY be used to indicate that this object is a JWS or JWE
using the JWS JSON Serialization or the JWE JSON Serialization.
Other type values MAY be used, and if not understood, SHOULD be
ignored. The "typ" value is a case sensitive string. Use of this
header parameter is OPTIONAL.
MIME Media Type [RFC2046] values MAY be used as "typ" values.
"typ" values SHOULD either be registered in the IANA JSON Web
Signature and Encryption Type Values registry Section 8.2 or be a
value that contains a Collision Resistant Namespace.
4.1.9. "cty" (Content Type) Header Parameter
The "cty" (content type) header parameter MAY be used to declare the
type of the secured content (the payload) in an application-specific
manner in contexts where this is useful to the application. This
parameter has no effect upon the JWS processing. Content type values
that are not understood SHOULD be ignored. The "cty" value is a case
sensitive string. Use of this header parameter is OPTIONAL.
The values used for the "cty" header parameter come from the same
value space as the "typ" header parameter, with the same rules
applying.
4.1.10. "crit" (Critical) Header Parameter
The "crit" (critical) header parameter indicates that extensions to
[[ this specification ]] are being used that MUST be understood and
processed. Its value is an array listing the header parameter names
defined by those extensions that are used in the JWS Header. If any
of the listed extension header parameters are not understood and
supported by the receiver, it MUST reject the JWS. Senders MUST NOT
include header parameter names defined by [[ this specification ]] or
by [JWA] for use with JWS, duplicate names, or names that do not
occur as header parameter names within the JWS Header in the "crit"
list. Senders MUST not use the empty list "[]" as the "crit" value.
Recipients MAY reject the JWS if the critical list contains any
header parameter names defined by [[ this specification ]] or by
[JWA] for use with JWS, or any other constraints on its use are
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violated. This header parameter MUST be integrity protected, and
therefore MUST occur only with the JWS Protected Header, when used.
Use of this header parameter is OPTIONAL. This header parameter MUST
be understood by implementations.
An example use, along with a hypothetical "exp" (expiration-time)
field is:
{"alg":"ES256",
"crit":["exp"],
"exp":1363284000
}
4.2. Public Header Parameter Names
Additional Header Parameter Names can be defined by those using JWSs.
However, in order to prevent collisions, any new Header Parameter
Name SHOULD either be registered in the IANA JSON Web Signature and
Encryption Header Parameters registry Section 8.1 or be a Public
Name: a value that contains a Collision Resistant Namespace. In each
case, the definer of the name or value needs to take reasonable
precautions to make sure they are in control of the part of the
namespace they use to define the Header Parameter Name.
New header parameters should be introduced sparingly, as they can
result in non-interoperable JWSs.
4.3. Private Header Parameter Names
A producer and consumer of a JWS may agree to use Header Parameter
Names that are Private Names: names that are not Reserved Names
Section 4.1 or Public Names Section 4.2. Unlike Public Names,
Private Names are subject to collision and should be used with
caution.
5. Producing and Consuming JWSs
5.1. Message Signing or MACing
To create a JWS, one MUST perform these steps. The order of the
steps is not significant in cases where there are no dependencies
between the inputs and outputs of the steps.
1. Create the content to be used as the JWS Payload.
2. Base64url encode the octets of the JWS Payload. This encoding
becomes the Encoded JWS Payload.
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3. Create a JWS Header containing the desired set of header
parameters. Note that white space is explicitly allowed in the
representation and no canonicalization need be performed before
encoding.
4. Base64url encode the octets of the UTF-8 representation of the
JWS Protected Header to create the Encoded JWS Header. If the
JWS Protected Header is not present (which can only happen when
using the JWS JSON Serialization and no "protected" member is
present), let the Encoded JWS Header be the empty string.
5. Compute the JWS Signature in the manner defined for the
particular algorithm being used over the JWS Signing Input (the
concatenation of the Encoded JWS Header, a period ('.')
character, and the Encoded JWS Payload). The "alg" (algorithm)
header parameter MUST be present in the JWS Header, with the
algorithm value accurately representing the algorithm used to
construct the JWS Signature.
6. Base64url encode the representation of the JWS Signature to
create the Encoded JWS Signature.
7. The three encoded parts are result values used in both the JWS
Compact Serialization and the JWS JSON Serialization
representations.
8. If the JWS JSON Serialization is being used, repeat this process
for each digital signature or MAC value being applied.
9. Create the desired serialized output. The JWS Compact
Serialization of this result is the concatenation of the Encoded
JWS Header, the Encoded JWS Payload, and the Encoded JWS
Signature in that order, with the three strings being separated
by two period ('.') characters. The JWS JSON Serialization is
described in Section 7.2.
5.2. Message Signature or MAC Validation
When validating a JWS, the following steps MUST be taken. The order
of the steps is not significant in cases where there are no
dependencies between the inputs and outputs of the steps. If any of
the listed steps fails, then the JWS MUST be rejected.
1. Parse the serialized input to determine the values of the JWS
Header, the Encoded JWS Payload, and the Encoded JWS Signature.
When using the JWS Compact Serialization, the Encoded JWS
Header, the Encoded JWS Payload, and the Encoded JWS Signature
are represented as text strings in that order, separated by two
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period ('.') characters. The JWS JSON Serialization is
described in Section 7.2.
2. The Encoded JWS Header MUST be successfully base64url decoded
following the restriction given in this specification that no
padding characters have been used.
3. Let the JWS Protected Header value be the result of base64url
decoding the Encoded JWS Header.
4. The resulting JWS Protected Header MUST be a completely valid
JSON object conforming to RFC 4627 [RFC4627].
5. If using the JWS Compact Serialization, let the JWS Header be
the JWS Protected Header; otherwise, when using the JWS JSON
Serialization, let the JWS Header be the union of the members of
the JWS Protected Header, the members of the "unprotected"
value, and the members of the corresponding "header" value, all
of which must be completely valid JSON objects.
6. The resulting JWS Header MUST NOT contain duplicate Header
Parameter Names. When using the JWS JSON Serialization, this
restriction includes that the same Header Parameter Name also
MUST NOT occur in distinct JSON Text Object values that together
comprise the JWS Header.
7. The resulting JWS Header MUST be validated to only include
parameters and values whose syntax and semantics are both
understood and supported or that are specified as being ignored
when not understood.
8. The Encoded JWS Payload MUST be successfully base64url decoded
following the restriction given in this specification that no
padding characters have been used.
9. The Encoded JWS Signature MUST be successfully base64url decoded
following the restriction given in this specification that no
padding characters have been used.
10. The JWS Signature MUST be successfully validated against the JWS
Signing Input (the concatenation of the Encoded JWS Header, a
period ('.') character, and the Encoded JWS Payload) in the
manner defined for the algorithm being used, which MUST be
accurately represented by the value of the "alg" (algorithm)
header parameter, which MUST be present.
11. If the JWS JSON Serialization is being used, repeat this process
for each digital signature or MAC value contained in the
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representation.
5.3. String Comparison Rules
Processing a JWS inevitably requires comparing known strings to
values in JSON objects. For example, in checking what the algorithm
is, the Unicode string encoding "alg" will be checked against the
member names in the JWS Header to see if there is a matching Header
Parameter Name. A similar process occurs when determining if the
value of the "alg" header parameter represents a supported algorithm.
Comparisons between JSON strings and other Unicode strings MUST be
performed as specified below:
1. Remove any JSON escaping from the input JSON string and convert
the string into a sequence of Unicode code points.
2. Likewise, convert the string to be compared against into a
sequence of Unicode code points.
3. Unicode Normalization [USA15] MUST NOT be applied at any point to
either the JSON string or to the string it is to be compared
against.
4. Comparisons between the two strings MUST be performed as a
Unicode code point to code point equality comparison. (Note that
values that originally used different Unicode encodings (UTF-8,
UTF-16, etc.) may result in the same code point values.)
Also, see the JSON security considerations in Section 9.2 and the
Unicode security considerations in Section 9.3.
6. Key Identification
It is necessary for the recipient of a JWS to be able to determine
the key that was employed for the digital signature or MAC operation.
The key employed can be identified using the Header Parameter methods
described in Section 4.1 or can be identified using methods that are
outside the scope of this specification. Specifically, the Header
Parameters "jku", "jwk", "x5u", "x5t", "x5c", and "kid" can be used
to identify the key used. The sender SHOULD include sufficient
information in the Header Parameters to identify the key used, unless
the application uses another means or convention to determine the key
used. Recipients MUST reject the input when the algorithm used
requires a key (which is true of all algorithms except for "none")
and the key used cannot be determined.
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7. Serializations
JWS objects use one of two serializations, the JWS Compact
Serialization or the JWS JSON Serialization. The JWS Compact
Serialization is mandatory to implement. Implementation of the JWS
JSON Serialization is OPTIONAL.
7.1. JWS Compact Serialization
The JWS Compact Serialization represents digitally signed or MACed
content as a compact URL-safe string. This string is the
concatenation of the Encoded JWS Header, the Encoded JWS Payload, and
the Encoded JWS Signature in that order, with the three strings being
separated by two period ('.') characters. Only one signature/MAC is
supported by the JWS Compact Serialization.
7.2. JWS JSON Serialization
The JWS JSON Serialization represents digitally signed or MACed
content as a JSON object. Unlike the JWS Compact Serialization,
content using the JWS JSON Serialization can be secured with more
than one digital signature and/or MAC value.
The representation is closely related to that used in the JWS Compact
Serialization, with the following differences for the JWS JSON
Serialization:
o Values in the JWS JSON Serialization are represented as members of
a JSON object, rather than as base64url encoded strings separated
by period ('.') characters. (However binary values and values
that are integrity protected are still base64url encoded.)
o The Encoded JWS Header value, if non-empty, is stored in the
"protected" member.
o The Encoded JWS Payload value is stored in the "payload" member.
o There can be multiple signature and/or MAC values, rather than
just one. A JSON array in the "signatures" member is used to hold
values that are specific to a particular signature or MAC
computation, with one array element per signature/MAC represented.
These array elements are JSON objects.
o Each Encoded JWS Signature value is stored in the "signature"
member of a JSON object that is an element of the "signatures"
array.
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o Some header parameter values, such as the "alg" value and
parameters used for selecting keys, can also differ for different
signature/MAC computations. Per-signature/MAC header parameter
values are stored in the "header" members of the same JSON objects
that are elements of the "signatures" array.
o Some header parameters, including the "alg" parameter, can be
shared among all signature/MAC computations. These header
parameters are stored in either of two top-level member(s) of the
JSON object: the "protected" member and the "unprotected" member.
The values of these members are JSON Text Objects containing
Header Parameters.
o Not all header parameters are integrity protected. The shared
header parameters in the "protected" member are integrity
protected, and are base64url encoded. The per-signature/MAC
header parameters in the "header" array element members and the
shared header parameters in the "unprotected" member are not
integrity protected. These JSON Text Objects containing header
parameters that are not integrity protected are not base64url
encoded.
o The header parameter values used when creating or validating
individual signature or MAC values are the union of the three sets
of header parameter values that may be present: (1) the per-
signature/MAC values in the "header" member of the signature/MAC's
array element, (2) the shared integrity-protected values in the
"protected" member, and (3) the shared non-integrity-protected
values in the "unprotected" member. The union of these sets of
header parameters comprises the JWS Header. The header parameter
names in the three locations MUST be disjoint.
The syntax of a JWS using the JWS JSON Serialization is as follows:
{"protected":<integrity-protected shared header contents>",
"unprotected":<non-integrity-protected shared header contents>",
"payload":"<payload contents>"
"signatures":[
{"header":"<per-signature unprotected header 1 contents>",
"signature":"<signature 1 contents>"},
...
{"header":"<per-signature unprotected header N contents>",
"signature":"<signature N contents>"}],
}
Of these members, only the "payload", "signatures", and "signature"
members MUST be present. At least one of the "header", "protected",
and "unprotected" members MUST be present so that an "alg" header
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parameter value is conveyed for each signature/MAC computation.
The contents of the Encoded JWS Payload and Encoded JWS Signature
values are exactly as defined in the rest of this specification.
They are interpreted and validated in the same manner, with each
corresponding Encoded JWS Signature and set of header parameter
values being created and validated together. The JWS Header values
used are the union of the header parameters in the "protected",
"unprotected", and corresponding "header" members, as described
earlier.
Each JWS Signature value is computed on the JWS Signing Input using
the parameters of the corresponding JWS Header value in the same
manner as for the JWS Compact Serialization. This has the desirable
property that each Encoded JWS Signature value in the "signatures"
array is identical to the value that would have been computed for the
same parameter in the JWS Compact Serialization, provided that the
Encoded JWS Header value (which represents the integrity-protected
header parameter values) matches that used in the JWS Compact
Serialization.
See Appendix A.6 for an example of computing a JWS using the JWS JSON
Serialization.
8. IANA Considerations
The following registration procedure is used for all the registries
established by this specification.
Values are registered with a Specification Required [RFC5226] after a
two-week review period on the [TBD]@ietf.org mailing list, on the
advice of one or more Designated Experts. However, to allow for the
allocation of values prior to publication, the Designated Expert(s)
may approve registration once they are satisfied that such a
specification will be published.
Registration requests must be sent to the [TBD]@ietf.org mailing list
for review and comment, with an appropriate subject (e.g., "Request
for access token type: example"). [[ Note to RFC-EDITOR: The name of
the mailing list should be determined in consultation with the IESG
and IANA. Suggested name: jose-reg-review. ]]
Within the review period, the Designated Expert(s) will either
approve or deny the registration request, communicating this decision
to the review list and IANA. Denials should include an explanation
and, if applicable, suggestions as to how to make the request
successful.
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IANA must only accept registry updates from the Designated Expert(s)
and should direct all requests for registration to the review mailing
list.
8.1. JSON Web Signature and Encryption Header Parameters Registry
This specification establishes the IANA JSON Web Signature and
Encryption Header Parameters registry for reserved JWS and JWE Header
Parameter Names. The registry records the reserved Header Parameter
Name and a reference to the specification that defines it. The same
Header Parameter Name MAY be registered multiple times, provided that
the parameter usage is compatible between the specifications.
Different registrations of the same Header Parameter Name will
typically use different Header Parameter Usage Location(s) values.
8.1.1. Registration Template
Header Parameter Name:
The name requested (e.g., "example"). This name is case
sensitive. Names that match other registered names in a case
insensitive manner SHOULD NOT be accepted.
Header Parameter Usage Location(s):
The header parameter usage locations, which should be one or more
of the values "JWS" or "JWE".
Change Controller:
For Standards Track RFCs, state "IETF". For others, give the name
of the responsible party. Other details (e.g., postal address,
email address, home page URI) may also be included.
Specification Document(s):
Reference to the document(s) that specify the parameter,
preferably including URI(s) that can be used to retrieve copies of
the document(s). An indication of the relevant sections may also
be included but is not required.
8.1.2. Initial Registry Contents
This specification registers the Header Parameter Names defined in
Section 4.1 in this registry.
o Header Parameter Name: "alg"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification Document(s): Section 4.1.1 of [[ this document ]]
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o Header Parameter Name: "jku"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification Document(s): Section 4.1.2 of [[ this document ]]
o Header Parameter Name: "jwk"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification document(s): Section 4.1.3 of [[ this document ]]
o Header Parameter Name: "x5u"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification Document(s): Section 4.1.4 of [[ this document ]]
o Header Parameter Name: "x5t"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification Document(s): Section 4.1.5 of [[ this document ]]
o Header Parameter Name: "x5c"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification Document(s): Section 4.1.6 of [[ this document ]]
o Header Parameter Name: "kid"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification Document(s): Section 4.1.7 of [[ this document ]]
o Header Parameter Name: "typ"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification Document(s): Section 4.1.8 of [[ this document ]]
o Header Parameter Name: "cty"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification Document(s): Section 4.1.9 of [[ this document ]]
o Header Parameter Name: "crit"
o Header Parameter Usage Location(s): JWS
o Change Controller: IETF
o Specification Document(s): Section 4.1.10 of [[ this document ]]
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8.2. JSON Web Signature and Encryption Type Values Registry
This specification establishes the IANA JSON Web Signature and
Encryption Type Values registry for values of the JWS and JWE "typ"
(type) header parameter. It is RECOMMENDED that all registered "typ"
values also include a MIME Media Type [RFC2046] value that the
registered value is a short name for. The registry records the "typ"
value, the MIME type value that it is an abbreviation for (if any),
and a reference to the specification that defines it.
MIME Media Type [RFC2046] values MUST NOT be directly registered as
new "typ" values; rather, new "typ" values MAY be registered as short
names for MIME types.
8.2.1. Registration Template
"typ" Header Parameter Value:
The name requested (e.g., "example"). This name is case
sensitive. Names that match other registered names in a case
insensitive manner SHOULD NOT be accepted.
Abbreviation for MIME Type:
The MIME type that this name is an abbreviation for (e.g.,
"application/example").
Change Controller:
For Standards Track RFCs, state "IETF". For others, give the name
of the responsible party. Other details (e.g., postal address,
email address, home page URI) may also be included.
Specification Document(s):
Reference to the document(s) that specify the parameter,
preferably including URI(s) that can be used to retrieve copies of
the document(s). An indication of the relevant sections may also
be included but is not required.
8.2.2. Initial Registry Contents
This specification registers the "JOSE" and "JOSE+JSON" type values
in this registry:
o "typ" Header Parameter Value: "JOSE"
o Abbreviation for MIME type: application/jose
o Change Controller: IETF
o Specification Document(s): Section 4.1.8 of [[ this document ]]
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o "typ" Header Parameter Value: "JOSE+JSON"
o Abbreviation for MIME type: application/jose+json
o Change Controller: IETF
o Specification Document(s): Section 4.1.8 of [[ this document ]]
8.3. Media Type Registration
8.3.1. Registry Contents
This specification registers the "application/jose" Media Type
[RFC2046] in the MIME Media Type registry [RFC4288], which can be
used to indicate that the content is a JWS or JWE object using the
JWS Compact Serialization or the JWE Compact Serialization and the
"application/jose+json" Media Type in the MIME Media Type registry,
which can be used to indicate that the content is a JWS or JWE object
using the JWS JSON Serialization or the JWE JSON Serialization.
o Type name: application
o Subtype name: jose
o Required parameters: n/a
o Optional parameters: n/a
o Encoding considerations: application/jose values are encoded as a
series of base64url encoded values (some of which may be the empty
string) separated by period ('.') characters.
o Security considerations: See the Security Considerations section
of [[ this document ]]
o Interoperability considerations: n/a
o Published specification: [[ this document ]]
o Applications that use this media type: OpenID Connect, Mozilla
Persona, Salesforce, Google, numerous others that use signed JWTs
o Additional information: Magic number(s): n/a, File extension(s):
n/a, Macintosh file type code(s): n/a
o Person & email address to contact for further information: Michael
B. Jones, mbj@microsoft.com
o Intended usage: COMMON
o Restrictions on usage: none
o Author: Michael B. Jones, mbj@microsoft.com
o Change Controller: IETF
o Type name: application
o Subtype name: jose+json
o Required parameters: n/a
o Optional parameters: n/a
o Encoding considerations: application/jose+json values are
represented as a JSON Object; UTF-8 encoding SHOULD be employed
for the JSON object.
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o Security considerations: See the Security Considerations section
of [[ this document ]]
o Interoperability considerations: n/a
o Published specification: [[ this document ]]
o Applications that use this media type: TBD
o Additional information: Magic number(s): n/a, File extension(s):
n/a, Macintosh file type code(s): n/a
o Person & email address to contact for further information: Michael
B. Jones, mbj@microsoft.com
o Intended usage: COMMON
o Restrictions on usage: none
o Author: Michael B. Jones, mbj@microsoft.com
o Change Controller: IETF
9. Security Considerations
9.1. Cryptographic Security Considerations
All of the security issues faced by any cryptographic application
must be faced by a JWS/JWE/JWK agent. Among these issues are
protecting the user's private and symmetric keys, preventing various
attacks, and helping the user avoid mistakes such as inadvertently
encrypting a message for the wrong recipient. The entire list of
security considerations is beyond the scope of this document, but
some significant concerns are listed here.
All the security considerations in XML DSIG 2.0
[W3C.CR-xmldsig-core2-20120124], also apply to this specification,
other than those that are XML specific. Likewise, many of the best
practices documented in XML Signature Best Practices
[W3C.WD-xmldsig-bestpractices-20110809] also apply to this
specification, other than those that are XML specific.
Keys are only as strong as the amount of entropy used to generate
them. A minimum of 128 bits of entropy should be used for all keys,
and depending upon the application context, more may be required. In
particular, it may be difficult to generate sufficiently random
values in some browsers and application environments.
Creators of JWSs should not allow third parties to insert arbitrary
content into the message without adding entropy not controlled by the
third party.
When utilizing TLS to retrieve information, the authority providing
the resource MUST be authenticated and the information retrieved MUST
be free from modification.
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When cryptographic algorithms are implemented in such a way that
successful operations take a different amount of time than
unsuccessful operations, attackers may be able to use the time
difference to obtain information about the keys employed. Therefore,
such timing differences must be avoided.
A SHA-1 hash is used when computing "x5t" (x.509 certificate
thumbprint) values, for compatibility reasons. Should an effective
means of producing SHA-1 hash collisions be developed, and should an
attacker wish to interfere with the use of a known certificate on a
given system, this could be accomplished by creating another
certificate whose SHA-1 hash value is the same and adding it to the
certificate store used by the intended victim. A prerequisite to
this attack succeeding is the attacker having write access to the
intended victim's certificate store.
If, in the future, certificate thumbprints need to be computed using
hash functions other than SHA-1, it is suggested that additional
related header parameters be defined for that purpose. For example,
it is suggested that a new "x5t#S256" (X.509 Certificate Thumbprint
using SHA-256) header parameter could be defined and used.
9.2. JSON Security Considerations
Strict JSON validation is a security requirement. If malformed JSON
is received, then the intent of the sender is impossible to reliably
discern. Ambiguous and potentially exploitable situations could
arise if the JSON parser used does not reject malformed JSON syntax.
Section 2.2 of the JavaScript Object Notation (JSON) specification
[RFC4627] states "The names within an object SHOULD be unique",
whereas this specification states that "Header Parameter Names within
this object MUST be unique; receipients MUST either reject JWSs with
duplicate Header Parameter Names or use a JSON parser that returns
only the lexically last duplicate member name, as specified in
Section 15.12 (The JSON Object) of ECMAScript 5.1 [ECMAScript]".
Thus, this specification requires that the Section 2.2 "SHOULD" be
treated as a "MUST" by senders and that it be either treated as a
"MUST" or in the manner specfied in ECMAScript 5.1 by receivers.
Ambiguous and potentially exploitable situations could arise if the
JSON parser used does not enforce the uniqueness of member names or
returns an unpredictable value for duplicate member names.
Some JSON parsers might not reject input that contains extra
significant characters after a valid input. For instance, the input
"{"tag":"value"}ABCD" contains a valid JSON object followed by the
extra characters "ABCD". Such input MUST be rejected in its
entirety.
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9.3. Unicode Comparison Security Considerations
Header Parameter Names and algorithm names are Unicode strings. For
security reasons, the representations of these names must be compared
verbatim after performing any escape processing (as per RFC 4627
[RFC4627], Section 2.5). This means, for instance, that these JSON
strings must compare as being equal ("sig", "\u0073ig"), whereas
these must all compare as being not equal to the first set or to each
other ("SIG", "Sig", "si\u0047").
JSON strings can contain characters outside the Unicode Basic
Multilingual Plane. For instance, the G clef character (U+1D11E) may
be represented in a JSON string as "\uD834\uDD1E". Ideally, JWS
implementations SHOULD ensure that characters outside the Basic
Multilingual Plane are preserved and compared correctly;
alternatively, if this is not possible due to these characters
exercising limitations present in the underlying JSON implementation,
then input containing them MUST be rejected.
9.4. TLS Requirements
Implementations MUST support TLS. Which version(s) ought to be
implemented will vary over time, and depend on the widespread
deployment and known security vulnerabilities at the time of
implementation. At the time of this writing, TLS version 1.2
[RFC5246] is the most recent version, but has very limited actual
deployment, and might not be readily available in implementation
toolkits. TLS version 1.0 [RFC2246] is the most widely deployed
version, and will give the broadest interoperability.
To protect against information disclosure and tampering,
confidentiality protection MUST be applied using TLS with a
ciphersuite that provides confidentiality and integrity protection.
Whenever TLS is used, a TLS server certificate check MUST be
performed, per RFC 6125 [RFC6125].
10. References
10.1. Normative References
[ECMAScript]
Ecma International, "ECMAScript Language Specification,
5.1 Edition", ECMA 262, June 2011.
[ITU.X690.1994]
International Telecommunications Union, "Information
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Technology - ASN.1 encoding rules: Specification of Basic
Encoding Rules (BER), Canonical Encoding Rules (CER) and
Distinguished Encoding Rules (DER)", ITU-T Recommendation
X.690, 1994.
[JWA] Jones, M., "JSON Web Algorithms (JWA)",
draft-ietf-jose-json-web-algorithms (work in progress),
July 2013.
[JWK] Jones, M., "JSON Web Key (JWK)",
draft-ietf-jose-json-web-key (work in progress),
July 2013.
[RFC1421] Linn, J., "Privacy Enhancement for Internet Electronic
Mail: Part I: Message Encryption and Authentication
Procedures", RFC 1421, February 1993.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046,
November 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0",
RFC 2246, January 1999.
[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", RFC 4288, December 2005.
[RFC4627] Crockford, D., "The application/json Media Type for
JavaScript Object Notation (JSON)", RFC 4627, July 2006.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, October 2006.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
Jones, et al. Expires January 12, 2014 [Page 26]
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[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008.
[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and
Verification of Domain-Based Application Service Identity
within Internet Public Key Infrastructure Using X.509
(PKIX) Certificates in the Context of Transport Layer
Security (TLS)", RFC 6125, March 2011.
[USA15] Davis, M., Whistler, K., and M. Deurst, "Unicode
Normalization Forms", Unicode Standard Annex 15, 09 2009.
[USASCII] American National Standards Institute, "Coded Character
Set -- 7-bit American Standard Code for Information
Interchange", ANSI X3.4, 1986.
[W3C.WD-xmldsig-bestpractices-20110809]
Datta, P. and F. Hirsch, "XML Signature Best Practices",
World Wide Web Consortium WD WD-xmldsig-bestpractices-
20110809, August 2011, <http://www.w3.org/TR/2011/
WD-xmldsig-bestpractices-20110809>.
10.2. Informative References
[CanvasApp]
Facebook, "Canvas Applications", 2010.
[JSS] Bradley, J. and N. Sakimura (editor), "JSON Simple Sign",
September 2010.
[JWE] Jones, M., Rescorla, E., and J. Hildebrand, "JSON Web
Encryption (JWE)", draft-ietf-jose-json-web-encryption
(work in progress), July 2013.
[JWT] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
(JWT)", draft-ietf-oauth-json-web-token (work in
progress), July 2013.
[MagicSignatures]
Panzer (editor), J., Laurie, B., and D. Balfanz, "Magic
Signatures", January 2011.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Jones, et al. Expires January 12, 2014 [Page 27]
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Unique IDentifier (UUID) URN Namespace", RFC 4122,
July 2005.
[W3C.CR-xmldsig-core2-20120124]
Eastlake, D., Reagle, J., Yiu, K., Solo, D., Datta, P.,
Hirsch, F., Cantor, S., and T. Roessler, "XML Signature
Syntax and Processing Version 2.0", World Wide Web
Consortium CR CR-xmldsig-core2-20120124, January 2012,
<http://www.w3.org/TR/2012/CR-xmldsig-core2-20120124>.
Appendix A. JWS Examples
This section provides several examples of JWSs. While these examples
all represent JSON Web Tokens (JWTs) [JWT], the payload can be any
base64url encoded content.
A.1. Example JWS using HMAC SHA-256
A.1.1. Encoding
The following example JWS Header declares that the data structure is
a JSON Web Token (JWT) [JWT] and the JWS Signing Input is secured
using the HMAC SHA-256 algorithm.
{"typ":"JWT",
"alg":"HS256"}
The following octet sequence contains the UTF-8 representation of the
JWS Header:
[123, 34, 116, 121, 112, 34, 58, 34, 74, 87, 84, 34, 44, 13, 10, 32,
34, 97, 108, 103, 34, 58, 34, 72, 83, 50, 53, 54, 34, 125]
Base64url encoding these octets yields this Encoded JWS Header value:
eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9
The JWS Payload used in this example is the octets of the UTF-8
representation of the JSON object below. (Note that the payload can
be any base64url encoded octet sequence, and need not be a base64url
encoded JSON object.)
{"iss":"joe",
"exp":1300819380,
"http://example.com/is_root":true}
The following octet sequence, which is the UTF-8 representation of
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the JSON object above, is the JWS Payload:
[123, 34, 105, 115, 115, 34, 58, 34, 106, 111, 101, 34, 44, 13, 10,
32, 34, 101, 120, 112, 34, 58, 49, 51, 48, 48, 56, 49, 57, 51, 56,
48, 44, 13, 10, 32, 34, 104, 116, 116, 112, 58, 47, 47, 101, 120, 97,
109, 112, 108, 101, 46, 99, 111, 109, 47, 105, 115, 95, 114, 111,
111, 116, 34, 58, 116, 114, 117, 101, 125]
Base64url encoding the JWS Payload yields this Encoded JWS Payload
value (with line breaks for display purposes only):
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
Concatenating the Encoded JWS Header, a period ('.') character, and
the Encoded JWS Payload yields this JWS Signing Input value (with
line breaks for display purposes only):
eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
The ASCII representation of the JWS Signing Input is the following
octet sequence:
[101, 121, 74, 48, 101, 88, 65, 105, 79, 105, 74, 75, 86, 49, 81,
105, 76, 65, 48, 75, 73, 67, 74, 104, 98, 71, 99, 105, 79, 105, 74,
73, 85, 122, 73, 49, 78, 105, 74, 57, 46, 101, 121, 74, 112, 99, 51,
77, 105, 79, 105, 74, 113, 98, 50, 85, 105, 76, 65, 48, 75, 73, 67,
74, 108, 101, 72, 65, 105, 79, 106, 69, 122, 77, 68, 65, 52, 77, 84,
107, 122, 79, 68, 65, 115, 68, 81, 111, 103, 73, 109, 104, 48, 100,
72, 65, 54, 76, 121, 57, 108, 101, 71, 70, 116, 99, 71, 120, 108, 76,
109, 78, 118, 98, 83, 57, 112, 99, 49, 57, 121, 98, 50, 57, 48, 73,
106, 112, 48, 99, 110, 86, 108, 102, 81]
HMACs are generated using keys. This example uses the symmetric key
represented in JSON Web Key [JWK] format below (with line breaks for
display purposes only):
{"kty":"oct",
"k":"AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75
aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow"
}
Running the HMAC SHA-256 algorithm on the octets of the ASCII
representation of the JWS Signing Input with this key yields this
octet sequence:
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[116, 24, 223, 180, 151, 153, 224, 37, 79, 250, 96, 125, 216, 173,
187, 186, 22, 212, 37, 77, 105, 214, 191, 240, 91, 88, 5, 88, 83,
132, 141, 121]
Base64url encoding the above HMAC output yields this Encoded JWS
Signature value:
dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk
Concatenating these values in the order Header.Payload.Signature with
period ('.') characters between the parts yields this complete JWS
representation using the JWS Compact Serialization (with line breaks
for display purposes only):
eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
.
dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk
A.1.2. Decoding
Decoding the JWS requires base64url decoding the Encoded JWS Header,
Encoded JWS Payload, and Encoded JWS Signature to produce the JWS
Header, JWS Payload, and JWS Signature octet sequences. The octet
sequence containing the UTF-8 representation of the JWS Header is
decoded into the JWS Header string.
A.1.3. Validating
Next we validate the decoded results. Since the "alg" parameter in
the header is "HS256", we validate the HMAC SHA-256 value contained
in the JWS Signature. If any of the validation steps fail, the JWS
MUST be rejected.
First, we validate that the JWS Header string is legal JSON.
To validate the HMAC value, we repeat the previous process of using
the correct key and the ASCII representation of the JWS Signing Input
as input to the HMAC SHA-256 function and then taking the output and
determining if it matches the JWS Signature. If it matches exactly,
the HMAC has been validated.
A.2. Example JWS using RSASSA-PKCS-v1_5 SHA-256
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A.2.1. Encoding
The JWS Header in this example is different from the previous example
in two ways: First, because a different algorithm is being used, the
"alg" value is different. Second, for illustration purposes only,
the optional "typ" parameter is not used. (This difference is not
related to the algorithm employed.) The JWS Header used is:
{"alg":"RS256"}
The following octet sequence contains the UTF-8 representation of the
JWS Header:
[123, 34, 97, 108, 103, 34, 58, 34, 82, 83, 50, 53, 54, 34, 125]
Base64url encoding these octets yields this Encoded JWS Header value:
eyJhbGciOiJSUzI1NiJ9
The JWS Payload used in this example, which follows, is the same as
in the previous example. Since the Encoded JWS Payload will
therefore be the same, its computation is not repeated here.
{"iss":"joe",
"exp":1300819380,
"http://example.com/is_root":true}
Concatenating the Encoded JWS Header, a period ('.') character, and
the Encoded JWS Payload yields this JWS Signing Input value (with
line breaks for display purposes only):
eyJhbGciOiJSUzI1NiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
The ASCII representation of the JWS Signing Input is the following
octet sequence:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 83, 85, 122, 73,
49, 78, 105, 74, 57, 46, 101, 121, 74, 112, 99, 51, 77, 105, 79, 105,
74, 113, 98, 50, 85, 105, 76, 65, 48, 75, 73, 67, 74, 108, 101, 72,
65, 105, 79, 106, 69, 122, 77, 68, 65, 52, 77, 84, 107, 122, 79, 68,
65, 115, 68, 81, 111, 103, 73, 109, 104, 48, 100, 72, 65, 54, 76,
121, 57, 108, 101, 71, 70, 116, 99, 71, 120, 108, 76, 109, 78, 118,
98, 83, 57, 112, 99, 49, 57, 121, 98, 50, 57, 48, 73, 106, 112, 48,
99, 110, 86, 108, 102, 81]
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This example uses the RSA key represented in JSON Web Key [JWK]
format below (with line breaks for display purposes only):
{"kty":"RSA",
"n":"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx
HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs
D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH
SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV
MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8
NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ",
"e":"AQAB",
"d":"Eq5xpGnNCivDflJsRQBXHx1hdR1k6Ulwe2JZD50LpXyWPEAeP88vLNO97I
jlA7_GQ5sLKMgvfTeXZx9SE-7YwVol2NXOoAJe46sui395IW_GO-pWJ1O0
BkTGoVEn2bKVRUCgu-GjBVaYLU6f3l9kJfFNS3E0QbVdxzubSu3Mkqzjkn
439X0M_V51gfpRLI9JYanrC4D4qAdGcopV_0ZHHzQlBjudU2QvXt4ehNYT
CBr6XCLQUShb1juUO1ZdiYoFaFQT5Tw8bGUl_x_jTj3ccPDVZFD9pIuhLh
BOneufuBiB4cS98l2SR_RQyGWSeWjnczT0QU91p1DhOVRuOopznQ"
}
The RSA private key is then passed to the RSA signing function, which
also takes the hash type, SHA-256, and the octets of the ASCII
representation of the JWS Signing Input as inputs. The result of the
digital signature is an octet sequence, which represents a big endian
integer. In this example, it is:
[112, 46, 33, 137, 67, 232, 143, 209, 30, 181, 216, 45, 191, 120, 69,
243, 65, 6, 174, 27, 129, 255, 247, 115, 17, 22, 173, 209, 113, 125,
131, 101, 109, 66, 10, 253, 60, 150, 238, 221, 115, 162, 102, 62, 81,
102, 104, 123, 0, 11, 135, 34, 110, 1, 135, 237, 16, 115, 249, 69,
229, 130, 173, 252, 239, 22, 216, 90, 121, 142, 232, 198, 109, 219,
61, 184, 151, 91, 23, 208, 148, 2, 190, 237, 213, 217, 217, 112, 7,
16, 141, 178, 129, 96, 213, 248, 4, 12, 167, 68, 87, 98, 184, 31,
190, 127, 249, 217, 46, 10, 231, 111, 36, 242, 91, 51, 187, 230, 244,
74, 230, 30, 177, 4, 10, 203, 32, 4, 77, 62, 249, 18, 142, 212, 1,
48, 121, 91, 212, 189, 59, 65, 238, 202, 208, 102, 171, 101, 25, 129,
253, 228, 141, 247, 127, 55, 45, 195, 139, 159, 175, 221, 59, 239,
177, 139, 93, 163, 204, 60, 46, 176, 47, 158, 58, 65, 214, 18, 202,
173, 21, 145, 18, 115, 160, 95, 35, 185, 232, 56, 250, 175, 132, 157,
105, 132, 41, 239, 90, 30, 136, 121, 130, 54, 195, 212, 14, 96, 69,
34, 165, 68, 200, 242, 122, 122, 45, 184, 6, 99, 209, 108, 247, 202,
234, 86, 222, 64, 92, 178, 33, 90, 69, 178, 194, 85, 102, 181, 90,
193, 167, 72, 160, 112, 223, 200, 163, 42, 70, 149, 67, 208, 25, 238,
251, 71]
Base64url encoding the digital signature produces this value for the
Encoded JWS Signature (with line breaks for display purposes only):
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cC4hiUPoj9Eetdgtv3hF80EGrhuB__dzERat0XF9g2VtQgr9PJbu3XOiZj5RZmh7
AAuHIm4Bh-0Qc_lF5YKt_O8W2Fp5jujGbds9uJdbF9CUAr7t1dnZcAcQjbKBYNX4
BAynRFdiuB--f_nZLgrnbyTyWzO75vRK5h6xBArLIARNPvkSjtQBMHlb1L07Qe7K
0GarZRmB_eSN9383LcOLn6_dO--xi12jzDwusC-eOkHWEsqtFZESc6BfI7noOPqv
hJ1phCnvWh6IeYI2w9QOYEUipUTI8np6LbgGY9Fs98rqVt5AXLIhWkWywlVmtVrB
p0igcN_IoypGlUPQGe77Rw
Concatenating these values in the order Header.Payload.Signature with
period ('.') characters between the parts yields this complete JWS
representation using the JWS Compact Serialization (with line breaks
for display purposes only):
eyJhbGciOiJSUzI1NiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
.
cC4hiUPoj9Eetdgtv3hF80EGrhuB__dzERat0XF9g2VtQgr9PJbu3XOiZj5RZmh7
AAuHIm4Bh-0Qc_lF5YKt_O8W2Fp5jujGbds9uJdbF9CUAr7t1dnZcAcQjbKBYNX4
BAynRFdiuB--f_nZLgrnbyTyWzO75vRK5h6xBArLIARNPvkSjtQBMHlb1L07Qe7K
0GarZRmB_eSN9383LcOLn6_dO--xi12jzDwusC-eOkHWEsqtFZESc6BfI7noOPqv
hJ1phCnvWh6IeYI2w9QOYEUipUTI8np6LbgGY9Fs98rqVt5AXLIhWkWywlVmtVrB
p0igcN_IoypGlUPQGe77Rw
A.2.2. Decoding
Decoding the JWS requires base64url decoding the Encoded JWS Header,
Encoded JWS Payload, and Encoded JWS Signature to produce the JWS
Header, JWS Payload, and JWS Signature octet sequences. The octet
sequence containing the UTF-8 representation of the JWS Header is
decoded into the JWS Header string.
A.2.3. Validating
Since the "alg" parameter in the header is "RS256", we validate the
RSASSA-PKCS-v1_5 SHA-256 digital signature contained in the JWS
Signature. If any of the validation steps fail, the JWS MUST be
rejected.
First, we validate that the JWS Header string is legal JSON.
Validating the JWS Signature is a little different from the previous
example. First, we base64url decode the Encoded JWS Signature to
produce a digital signature S to check. We then pass (n, e), S and
the octets of the ASCII representation of the JWS Signing Input to an
RSASSA-PKCS-v1_5 signature verifier that has been configured to use
the SHA-256 hash function.
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A.3. Example JWS using ECDSA P-256 SHA-256
A.3.1. Encoding
The JWS Header for this example differs from the previous example
because a different algorithm is being used. The JWS Header used is:
{"alg":"ES256"}
The following octet sequence contains the UTF-8 representation of the
JWS Header:
[123, 34, 97, 108, 103, 34, 58, 34, 69, 83, 50, 53, 54, 34, 125]
Base64url encoding these octets yields this Encoded JWS Header value:
eyJhbGciOiJFUzI1NiJ9
The JWS Payload used in this example, which follows, is the same as
in the previous examples. Since the Encoded JWS Payload will
therefore be the same, its computation is not repeated here.
{"iss":"joe",
"exp":1300819380,
"http://example.com/is_root":true}
Concatenating the Encoded JWS Header, a period ('.') character, and
the Encoded JWS Payload yields this JWS Signing Input value (with
line breaks for display purposes only):
eyJhbGciOiJFUzI1NiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
The ASCII representation of the JWS Signing Input is the following
octet sequence:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 70, 85, 122, 73,
49, 78, 105, 74, 57, 46, 101, 121, 74, 112, 99, 51, 77, 105, 79, 105,
74, 113, 98, 50, 85, 105, 76, 65, 48, 75, 73, 67, 74, 108, 101, 72,
65, 105, 79, 106, 69, 122, 77, 68, 65, 52, 77, 84, 107, 122, 79, 68,
65, 115, 68, 81, 111, 103, 73, 109, 104, 48, 100, 72, 65, 54, 76,
121, 57, 108, 101, 71, 70, 116, 99, 71, 120, 108, 76, 109, 78, 118,
98, 83, 57, 112, 99, 49, 57, 121, 98, 50, 57, 48, 73, 106, 112, 48,
99, 110, 86, 108, 102, 81]
This example uses the elliptic curve key represented in JSON Web Key
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[JWK] format below:
{"kty":"EC",
"crv":"P-256",
"x":"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU",
"y":"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0",
"d":"jpsQnnGQmL-YBIffH1136cspYG6-0iY7X1fCE9-E9LI"
}
The ECDSA private part d is then passed to an ECDSA signing function,
which also takes the curve type, P-256, the hash type, SHA-256, and
the octets of the ASCII representation of the JWS Signing Input as
inputs. The result of the digital signature is the EC point (R, S),
where R and S are unsigned integers. In this example, the R and S
values, given as octet sequences representing big endian integers
are:
+--------+----------------------------------------------------------+
| Result | Value |
| Name | |
+--------+----------------------------------------------------------+
| R | [14, 209, 33, 83, 121, 99, 108, 72, 60, 47, 127, 21, 88, |
| | 7, 212, 2, 163, 178, 40, 3, 58, 249, 124, 126, 23, 129, |
| | 154, 195, 22, 158, 166, 101] |
| S | [197, 10, 7, 211, 140, 60, 112, 229, 216, 241, 45, 175, |
| | 8, 74, 84, 128, 166, 101, 144, 197, 242, 147, 80, 154, |
| | 143, 63, 127, 138, 131, 163, 84, 213] |
+--------+----------------------------------------------------------+
Concatenating the S array to the end of the R array and base64url
encoding the result produces this value for the Encoded JWS Signature
(with line breaks for display purposes only):
DtEhU3ljbEg8L38VWAfUAqOyKAM6-Xx-F4GawxaepmXFCgfTjDxw5djxLa8ISlSA
pmWQxfKTUJqPP3-Kg6NU1Q
Concatenating these values in the order Header.Payload.Signature with
period ('.') characters between the parts yields this complete JWS
representation using the JWS Compact Serialization (with line breaks
for display purposes only):
eyJhbGciOiJFUzI1NiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
.
DtEhU3ljbEg8L38VWAfUAqOyKAM6-Xx-F4GawxaepmXFCgfTjDxw5djxLa8ISlSA
pmWQxfKTUJqPP3-Kg6NU1Q
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A.3.2. Decoding
Decoding the JWS requires base64url decoding the Encoded JWS Header,
Encoded JWS Payload, and Encoded JWS Signature to produce the JWS
Header, JWS Payload, and JWS Signature octet sequences. The octet
sequence containing the UTF-8 representation of the JWS Header is
decoded into the JWS Header string.
A.3.3. Validating
Since the "alg" parameter in the header is "ES256", we validate the
ECDSA P-256 SHA-256 digital signature contained in the JWS Signature.
If any of the validation steps fail, the JWS MUST be rejected.
First, we validate that the JWS Header string is legal JSON.
Validating the JWS Signature is a little different from the first
example. First, we base64url decode the Encoded JWS Signature as in
the previous examples but we then need to split the 64 member octet
sequence that must result into two 32 octet sequences, the first R
and the second S. We then pass (x, y), (R, S) and the octets of the
ASCII representation of the JWS Signing Input to an ECDSA signature
verifier that has been configured to use the P-256 curve with the
SHA-256 hash function.
As explained in Section 3.4 of the JSON Web Algorithms (JWA) [JWA]
specification, the use of the K value in ECDSA means that we cannot
validate the correctness of the digital signature in the same way we
validated the correctness of the HMAC. Instead, implementations MUST
use an ECDSA validator to validate the digital signature.
A.4. Example JWS using ECDSA P-521 SHA-512
A.4.1. Encoding
The JWS Header for this example differs from the previous example
because a different ECDSA curve and hash function are used. The JWS
Header used is:
{"alg":"ES512"}
The following octet sequence contains the UTF-8 representation of the
JWS Header:
[123, 34, 97, 108, 103, 34, 58, 34, 69, 83, 53, 49, 50, 34, 125]
Base64url encoding these octets yields this Encoded JWS Header value:
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eyJhbGciOiJFUzUxMiJ9
The JWS Payload used in this example, is the ASCII string "Payload".
The representation of this string is the octet sequence:
[80, 97, 121, 108, 111, 97, 100]
Base64url encoding these octets yields this Encoded JWS Payload
value:
UGF5bG9hZA
Concatenating the Encoded JWS Header, a period ('.') character, and
the Encoded JWS Payload yields this JWS Signing Input value:
eyJhbGciOiJFUzUxMiJ9.UGF5bG9hZA
The ASCII representation of the JWS Signing Input is the following
octet sequence:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 70, 85, 122, 85,
120, 77, 105, 74, 57, 46, 85, 71, 70, 53, 98, 71, 57, 104, 90, 65]
This example uses the elliptic curve key represented in JSON Web Key
[JWK] format below (with line breaks for display purposes only):
{"kty":"EC",
"crv":"P-521",
"x":"AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_
NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk",
"y":"ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDl
y79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2",
"d":"AY5pb7A0UFiB3RELSD64fTLOSV_jazdF7fLYyuTw8lOfRhWg6Y6rUrPA
xerEzgdRhajnu0ferB0d53vM9mE15j2C"
}
The ECDSA private part d is then passed to an ECDSA signing function,
which also takes the curve type, P-521, the hash type, SHA-512, and
the octets of the ASCII representation of the JWS Signing Input as
inputs. The result of the digital signature is the EC point (R, S),
where R and S are unsigned integers. In this example, the R and S
values, given as octet sequences representing big endian integers
are:
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+--------+----------------------------------------------------------+
| Result | Value |
| Name | |
+--------+----------------------------------------------------------+
| R | [1, 220, 12, 129, 231, 171, 194, 209, 232, 135, 233, |
| | 117, 247, 105, 122, 210, 26, 125, 192, 1, 217, 21, 82, |
| | 91, 45, 240, 255, 83, 19, 34, 239, 71, 48, 157, 147, |
| | 152, 105, 18, 53, 108, 163, 214, 68, 231, 62, 153, 150, |
| | 106, 194, 164, 246, 72, 143, 138, 24, 50, 129, 223, 133, |
| | 206, 209, 172, 63, 237, 119, 109] |
| S | [0, 111, 6, 105, 44, 5, 41, 208, 128, 61, 152, 40, 92, |
| | 61, 152, 4, 150, 66, 60, 69, 247, 196, 170, 81, 193, |
| | 199, 78, 59, 194, 169, 16, 124, 9, 143, 42, 142, 131, |
| | 48, 206, 238, 34, 175, 83, 203, 220, 159, 3, 107, 155, |
| | 22, 27, 73, 111, 68, 68, 21, 238, 144, 229, 232, 148, |
| | 188, 222, 59, 242, 103] |
+--------+----------------------------------------------------------+
Concatenating the S array to the end of the R array and base64url
encoding the result produces this value for the Encoded JWS Signature
(with line breaks for display purposes only):
AdwMgeerwtHoh-l192l60hp9wAHZFVJbLfD_UxMi70cwnZOYaRI1bKPWROc-mZZq
wqT2SI-KGDKB34XO0aw_7XdtAG8GaSwFKdCAPZgoXD2YBJZCPEX3xKpRwcdOO8Kp
EHwJjyqOgzDO7iKvU8vcnwNrmxYbSW9ERBXukOXolLzeO_Jn
Concatenating these values in the order Header.Payload.Signature with
period ('.') characters between the parts yields this complete JWS
representation using the JWS Compact Serialization (with line breaks
for display purposes only):
eyJhbGciOiJFUzUxMiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
.
AdwMgeerwtHoh-l192l60hp9wAHZFVJbLfD_UxMi70cwnZOYaRI1bKPWROc-mZZq
wqT2SI-KGDKB34XO0aw_7XdtAG8GaSwFKdCAPZgoXD2YBJZCPEX3xKpRwcdOO8Kp
EHwJjyqOgzDO7iKvU8vcnwNrmxYbSW9ERBXukOXolLzeO_Jn
A.4.2. Decoding
Decoding the JWS requires base64url decoding the Encoded JWS Header,
Encoded JWS Payload, and Encoded JWS Signature to produce the JWS
Header, JWS Payload, and JWS Signature octet sequences. The octet
sequence containing the UTF-8 representation of the JWS Header is
decoded into the JWS Header string.
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A.4.3. Validating
Since the "alg" parameter in the header is "ES512", we validate the
ECDSA P-521 SHA-512 digital signature contained in the JWS Signature.
If any of the validation steps fail, the JWS MUST be rejected.
First, we validate that the JWS Header string is legal JSON.
Validating the JWS Signature is similar to the previous example.
First, we base64url decode the Encoded JWS Signature as in the
previous examples but we then need to split the 132 member octet
sequence that must result into two 66 octet sequences, the first R
and the second S. We then pass (x, y), (R, S) and the octets of the
ASCII representation of the JWS Signing Input to an ECDSA signature
verifier that has been configured to use the P-521 curve with the
SHA-512 hash function.
As explained in Section 3.4 of the JSON Web Algorithms (JWA) [JWA]
specification, the use of the K value in ECDSA means that we cannot
validate the correctness of the digital signature in the same way we
validated the correctness of the HMAC. Instead, implementations MUST
use an ECDSA validator to validate the digital signature.
A.5. Example Plaintext JWS
The following example JWS Header declares that the encoded object is
a Plaintext JWS:
{"alg":"none"}
Base64url encoding the octets of the UTF-8 representation of the JWS
Header yields this Encoded JWS Header:
eyJhbGciOiJub25lIn0
The JWS Payload used in this example, which follows, is the same as
in the previous examples. Since the Encoded JWS Payload will
therefore be the same, its computation is not repeated here.
{"iss":"joe",
"exp":1300819380,
"http://example.com/is_root":true}
The Encoded JWS Signature is the empty string.
Concatenating these parts in the order Header.Payload.Signature with
period ('.') characters between the parts yields this complete JWS
(with line breaks for display purposes only):
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eyJhbGciOiJub25lIn0
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
.
A.6. Example JWS Using JWS JSON Serialization
This section contains an example using the JWS JSON Serialization.
This example demonstrates the capability for conveying multiple
digital signatures and/or MACs for the same payload.
The Encoded JWS Payload used in this example is the same as that used
in the examples in Appendix A.2 (with line breaks for display
purposes only):
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
Two digital signatures are used in this example: both using RSASSA-
PKCS-v1_5 SHA-256. For the first, the JWS Protected Header and key
are the same as in Appendix A.2, resulting in the same JWS Signature
value; therefore, its computation is not repeated here. For the
second a different key is used, which is provided in Appendix A.6.5;
its computation follows the same procedure as the first, so it is not
detailed here either, other than including the resulting Encoded JWS
Signature value.
A.6.1. JWS Protected Header
The JWS Protected Header value used for both computations is:
{"alg":"RS256"}
Base64url encoding these octets yields this Encoded JWS Header value:
eyJhbGciOiJSUzI1NiJ9
A.6.2. JWS Per-Signature Unprotected Headers
Key ID values are supplied for both keys using per-signature header
parameters. The two values used to represent these Key IDs are:
{"kid":"2010-12-29"}
and:
{"kid":"e9bc097a-ce51-4036-9562-d2ade882db0d"}
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A.6.3. Complete JWS Header Values
Combining the protected and per-signature header values supplied, the
JWS Header values used for the first and second signatures
respectively are:
{"alg":"RS256",
"kid":"2010-12-29"}
and:
{"alg":"RS256",
"kid":"e9bc097a-ce51-4036-9562-d2ade882db0d"}
A.6.4. Complete JWS JSON Serialization Representation
The complete JSON Web Signature JSON Serialization for these values
is as follows (with line breaks for display purposes only):
{"protected":"eyJhbGciOiJSUzI1NiJ9",
"payload":
"eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGF
tcGxlLmNvbS9pc19yb290Ijp0cnVlfQ",
"signatures":[
{"header":
{"kid":"2010-12-29"},
"signature":
"cC4hiUPoj9Eetdgtv3hF80EGrhuB__dzERat0XF9g2VtQgr9PJbu3XOiZj5RZ
mh7AAuHIm4Bh-0Qc_lF5YKt_O8W2Fp5jujGbds9uJdbF9CUAr7t1dnZcAcQjb
KBYNX4BAynRFdiuB--f_nZLgrnbyTyWzO75vRK5h6xBArLIARNPvkSjtQBMHl
b1L07Qe7K0GarZRmB_eSN9383LcOLn6_dO--xi12jzDwusC-eOkHWEsqtFZES
c6BfI7noOPqvhJ1phCnvWh6IeYI2w9QOYEUipUTI8np6LbgGY9Fs98rqVt5AX
LIhWkWywlVmtVrBp0igcN_IoypGlUPQGe77Rw"},
{"header":
{"kid":"e9bc097a-ce51-4036-9562-d2ade882db0d"},
"signature":
"m2nhGPQGjPEDIotJnzcnlhUZnXeg0xzLVbh6NZzthY8yU3klJYaENE1aLAUtL
cq-TmEeYIr30ruGH2kNFqW4-oc7LcTQu9-7ItRhfi0kKeN1zNAAUemfNYXaXA
1JayiiCl7m9ylhLKIsvdXhFvV7XDSbUMnVoO9Yu5_ROKOJMkeU6ywR8DDcHmu
B2KcLMfpHn1FqnUnojxwfOg1Eqyb_ppeDTm9t_h8FoQgHqRpNgsTTvxI9vSPE
ZrWTkSf_D4ci6p06DM_nE6FbptYF3ENHF8NpGgncv_D_h9AIrZU5-6ee2HB24
jtN9qOHw2pkVrvhtxdsSJdeG6uJqiFs0ArwQQ"}]
}
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A.6.5. RSA Key Used for Second Signature
The second signature in this example uses the RSA key represented in
JSON Web Key [JWK] format below (with line breaks for display
purposes only):
{"kty":"RSA",
"n":"oHiJbb8NGB0P2UQjpJghsz4WM4Y85HCsCz45EBqi1frHtzhnZawUsuJ8dI
fDw3xbrkHaxHFShKGRRwh18G10KMQarocrryim350FvFwHNNsLnWBjGUGX
bBlozpM_AZ2aOm_I-zbKYNwqxBX8wTrNLFnZOqRjA0zDtEwTZ24aAnqt0y
3ahtQaxpxu1Ysfh-MrAC3AJ86wwprZCrnjj46zdavuu1gMuSRuZEwiJxSR
uCwOZBVND1KWNZwuxOecmJhVkbjD1YZrSwp16UzXPs1fqgbq3YsE8e_LHC
BfwBikrIQKwe8tjJnGjHUR3wwaBS_f05d4D-Y8KjNody4p8rFMIQ",
"e":"AQAB",
"d":"djLy_3x3V6iocN-o5WcNg6qazc718Uow34MwovULtlOnYgTQ3GoZQP5kr6
0E_GwQV9W4H3RdVMZxbQIFZVgp9JEmGiIEgluONy3A-NJMmJkz__Lsa8EN
mRlKQsbg5P7CiIKoZqof_aKOeaq8Z1Q5po5z3KcTK24SxS44KLpHvESYK5
9Re4Bnp_OLvFokjpfZ1fSVtwkQlXfpoclrl7mdfO6TMjOqvL6aXO8uJbIx
StHcOBO6IjSYglY47QG64fQd-DkVAQo3sG6RlQSJDXnsV7ow2gNO2gL0X6
ja2ff8UQ0W0tsalSDZ05DnaPBFSe0BDhyhyt7RnGwbz34oTWZdAQ"
}
Appendix B. "x5c" (X.509 Certificate Chain) Example
The JSON array below is an example of a certificate chain that could
be used as the value of an "x5c" (X.509 Certificate Chain) header
parameter, per Section 4.1.6. Note that since these strings contain
base64 encoded (not base64url encoded) values, they are allowed to
contain white space and line breaks.
["MIIE3jCCA8agAwIBAgICAwEwDQYJKoZIhvcNAQEFBQAwYzELMAkGA1UEBhMCVVM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keS5jb20wRgYDVR0fBD8wPTA7oDmgN4Y1aHR0cDovL2NlcnRpZmljYXRlcy5nb2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",
"MIIE+zCCBGSgAwIBAgICAQ0wDQYJKoZIhvcNAQEFBQAwgbsxJDAiBgNVBAcTG1Z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",
"MIIC5zCCAlACAQEwDQYJKoZIhvcNAQEFBQAwgbsxJDAiBgNVBAcTG1ZhbGlDZXJ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vIWZJV16vYdA757tn2VUdZZUcOBVXc65g2PFxTXdMwzzjsvUGJ7SVCCSRrCl6zf
N1SLUzm1NZ9WlmpZdRJEy0kTRxQb7XBhVQ7/nHk01xC+YDgkRoKWzk2Z/M/VXwb
P7RfZHM047QSv4dk+NoS/zcnwbNDu+97bi5p9wIDAQABMA0GCSqGSIb3DQEBBQU
AA4GBADt/UG9vUJSZSWI4OB9L+KXIPqeCgfYrx+jFzug6EILLGACOTb2oWH+heQ
C1u+mNr0HZDzTuIYEZoDJJKPTEjlbVUjP9UNV+mWwD5MlM/Mtsq2azSiGM5bUMM
j4QssxsodyamEwCW/POuZ6lcg5Ktz885hZo+L7tdEy8W9ViH0Pd"]
Appendix C. Notes on implementing base64url encoding without padding
This appendix describes how to implement base64url encoding and
decoding functions without padding based upon standard base64
encoding and decoding functions that do use padding.
To be concrete, example C# code implementing these functions is shown
below. Similar code could be used in other languages.
static string base64urlencode(byte [] arg)
{
string s = Convert.ToBase64String(arg); // Regular base64 encoder
s = s.Split('=')[0]; // Remove any trailing '='s
s = s.Replace('+', '-'); // 62nd char of encoding
s = s.Replace('/', '_'); // 63rd char of encoding
return s;
}
static byte [] base64urldecode(string arg)
{
string s = arg;
s = s.Replace('-', '+'); // 62nd char of encoding
s = s.Replace('_', '/'); // 63rd char of encoding
switch (s.Length % 4) // Pad with trailing '='s
{
case 0: break; // No pad chars in this case
case 2: s += "=="; break; // Two pad chars
case 3: s += "="; break; // One pad char
default: throw new System.Exception(
"Illegal base64url string!");
}
return Convert.FromBase64String(s); // Standard base64 decoder
}
As per the example code above, the number of '=' padding characters
that needs to be added to the end of a base64url encoded string
without padding to turn it into one with padding is a deterministic
function of the length of the encoded string. Specifically, if the
length mod 4 is 0, no padding is added; if the length mod 4 is 2, two
'=' padding characters are added; if the length mod 4 is 3, one '='
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padding character is added; if the length mod 4 is 1, the input is
malformed.
An example correspondence between unencoded and encoded values
follows. The octet sequence below encodes into the string below,
which when decoded, reproduces the octet sequence.
3 236 255 224 193
A-z_4ME
Appendix D. Negative Test Case for "crit" Header Parameter
Conforming implementations must reject input containing critical
extensions that are not understood or cannot be processed. The
following JWS must be rejected by all implementations, because it
uses an extension header parameter name
"http://example.invalid/UNDEFINED" that they do not understand. Any
other similar input, in which the use of the value
"http://example.invalid/UNDEFINED" is substituted for any other
header parameter name not understood by the implementation, must also
be rejected.
The JWS Header value for this JWS is:
{"alg":"none",
"crit":["http://example.invalid/UNDEFINED"],
"http://example.invalid/UNDEFINED":true
}
The complete JWS that must be rejected is as follows (with line
breaks for display purposes only):
eyJhbGciOiJub25lIiwNCiAiY3JpdCI6WyJodHRwOi8vZXhhbXBsZS5jb20vVU5ERU
ZJTkVEIl0sDQogImh0dHA6Ly9leGFtcGxlLmNvbS9VTkRFRklORUQiOnRydWUNCn0.
RkFJTA.
Appendix E. Acknowledgements
Solutions for signing JSON content were previously explored by Magic
Signatures [MagicSignatures], JSON Simple Sign [JSS], and Canvas
Applications [CanvasApp], all of which influenced this draft.
Thanks to Axel Nennker for his early implementation and feedback on
the JWS and JWE specifications.
This specification is the work of the JOSE Working Group, which
includes dozens of active and dedicated participants. In particular,
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the following individuals contributed ideas, feedback, and wording
that influenced this specification:
Dirk Balfanz, Richard Barnes, Brian Campbell, Breno de Medeiros, Dick
Hardt, Joe Hildebrand, Jeff Hodges, Edmund Jay, Yaron Y. Goland, Ben
Laurie, James Manger, Matt Miller, Tony Nadalin, Axel Nennker, John
Panzer, Emmanuel Raviart, Eric Rescorla, Jim Schaad, Paul Tarjan,
Hannes Tschofenig, and Sean Turner.
Jim Schaad and Karen O'Donoghue chaired the JOSE working group and
Sean Turner and Stephen Farrell served as Security area directors
during the creation of this specification.
Appendix F. Document History
[[ to be removed by the RFC editor before publication as an RFC ]]
-12
o Clarified that the "typ" and "cty" header parameters are used in
an application-specific manner and have no effect upon the JWS
processing.
o Replaced the MIME types "application/jws+json" and
"application/jws" with "application/jose+json" and
"application/jose".
o Stated that receipients MUST either reject JWSs with duplicate
Header Parameter Names or use a JSON parser that returns only the
lexically last duplicate member name.
o Added a Serializations section with parallel treatment of the JWS
Compact Serialization and the JWS JSON Serialization and also
moved the former Implementation Considerations content there.
-11
o Added Key Identification section.
o For the JWS JSON Serialization, enable header parameter values to
be specified in any of three parameters: the "protected" member
that is integrity protected and shared among all recipients, the
"unprotected" member that is not integrity protected and shared
among all recipients, and the "header" member that is not
integrity protected and specific to a particular recipient. (This
does not affect the JWS Compact Serialization, in which all header
parameter values are in a single integrity protected JWE Header
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value.)
o Removed suggested compact serialization for multiple digital
signatures and/or MACs.
o Changed the MIME type name "application/jws-js" to
"application/jws+json", addressing issue #22.
o Tightened the description of the "crit" (critical) header
parameter.
o Added a negative test case for the "crit" header parameter
-10
o Added an appendix suggesting a possible compact serialization for
JWSs with multiple digital signatures and/or MACs.
-09
o Added JWS JSON Serialization, as specified by
draft-jones-jose-jws-json-serialization-04.
o Registered "application/jws-js" MIME type and "JWS-JS" typ header
parameter value.
o Defined that the default action for header parameters that are not
understood is to ignore them unless specifically designated as
"MUST be understood" or included in the new "crit" (critical)
header parameter list. This addressed issue #6.
o Changed term "JWS Secured Input" to "JWS Signing Input".
o Changed from using the term "byte" to "octet" when referring to 8
bit values.
o Changed member name from "recipients" to "signatures" in the JWS
JSON Serialization.
o Added complete values using the JWS Compact Serialization for all
examples.
-08
o Applied editorial improvements suggested by Jeff Hodges and Hannes
Tschofenig. Many of these simplified the terminology used.
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o Clarified statements of the form "This header parameter is
OPTIONAL" to "Use of this header parameter is OPTIONAL".
o Added a Header Parameter Usage Location(s) field to the IANA JSON
Web Signature and Encryption Header Parameters registry.
o Added seriesInfo information to Internet Draft references.
-07
o Updated references.
-06
o Changed "x5c" (X.509 Certificate Chain) representation from being
a single string to being an array of strings, each containing a
single base64 encoded DER certificate value, representing elements
of the certificate chain.
o Applied changes made by the RFC Editor to RFC 6749's registry
language to this specification.
-05
o Added statement that "StringOrURI values are compared as case-
sensitive strings with no transformations or canonicalizations
applied".
o Indented artwork elements to better distinguish them from the body
text.
-04
o Completed JSON Security Considerations section, including
considerations about rejecting input with duplicate member names.
o Completed security considerations on the use of a SHA-1 hash when
computing "x5t" (x.509 certificate thumbprint) values.
o Refer to the registries as the primary sources of defined values
and then secondarily reference the sections defining the initial
contents of the registries.
o Normatively reference XML DSIG 2.0 [W3C.CR-xmldsig-core2-20120124]
for its security considerations.
o Added this language to Registration Templates: "This name is case
sensitive. Names that match other registered names in a case
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insensitive manner SHOULD NOT be accepted."
o Reference draft-jones-jose-jws-json-serialization instead of
draft-jones-json-web-signature-json-serialization.
o Described additional open issues.
o Applied editorial suggestions.
-03
o Added the "cty" (content type) header parameter for declaring type
information about the secured content, as opposed to the "typ"
(type) header parameter, which declares type information about
this object.
o Added "Collision Resistant Namespace" to the terminology section.
o Reference ITU.X690.1994 for DER encoding.
o Added an example JWS using ECDSA P-521 SHA-512. This has
particular illustrative value because of the use of the 521 bit
integers in the key and signature values. This is also an example
in which the payload is not a base64url encoded JSON object.
o Added an example "x5c" value.
o No longer say "the UTF-8 representation of the JWS Secured Input
(which is the same as the ASCII representation)". Just call it
"the ASCII representation of the JWS Secured Input".
o Added Registration Template sections for defined registries.
o Added Registry Contents sections to populate registry values.
o Changed name of the JSON Web Signature and Encryption "typ" Values
registry to be the JSON Web Signature and Encryption Type Values
registry, since it is used for more than just values of the "typ"
parameter.
o Moved registries JSON Web Signature and Encryption Header
Parameters and JSON Web Signature and Encryption Type Values to
the JWS specification.
o Numerous editorial improvements.
-02
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o Clarified that it is an error when a "kid" value is included and
no matching key is found.
o Removed assumption that "kid" (key ID) can only refer to an
asymmetric key.
o Clarified that JWSs with duplicate Header Parameter Names MUST be
rejected.
o Clarified the relationship between "typ" header parameter values
and MIME types.
o Registered application/jws MIME type and "JWS" typ header
parameter value.
o Simplified JWK terminology to get replace the "JWK Key Object" and
"JWK Container Object" terms with simply "JSON Web Key (JWK)" and
"JSON Web Key Set (JWK Set)" and to eliminate potential confusion
between single keys and sets of keys. As part of this change, the
Header Parameter Name for a public key value was changed from
"jpk" (JSON Public Key) to "jwk" (JSON Web Key).
o Added suggestion on defining additional header parameters such as
"x5t#S256" in the future for certificate thumbprints using hash
algorithms other than SHA-1.
o Specify RFC 2818 server identity validation, rather than RFC 6125
(paralleling the same decision in the OAuth specs).
o Generalized language to refer to Message Authentication Codes
(MACs) rather than Hash-based Message Authentication Codes (HMACs)
unless in a context specific to HMAC algorithms.
o Reformatted to give each header parameter its own section heading.
-01
o Moved definition of Plaintext JWSs (using "alg":"none") here from
the JWT specification since this functionality is likely to be
useful in more contexts that just for JWTs.
o Added "jpk" and "x5c" header parameters for including JWK public
keys and X.509 certificate chains directly in the header.
o Clarified that this specification is defining the JWS Compact
Serialization. Referenced the new JWS-JS spec, which defines the
JWS JSON Serialization.
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o Added text "New header parameters should be introduced sparingly
since an implementation that does not understand a parameter MUST
reject the JWS".
o Clarified that the order of the creation and validation steps is
not significant in cases where there are no dependencies between
the inputs and outputs of the steps.
o Changed "no canonicalization is performed" to "no canonicalization
need be performed".
o Corrected the Magic Signatures reference.
o Made other editorial improvements suggested by JOSE working group
participants.
-00
o Created the initial IETF draft based upon
draft-jones-json-web-signature-04 with no normative changes.
o Changed terminology to no longer call both digital signatures and
HMACs "signatures".
Authors' Addresses
Michael B. Jones
Microsoft
Email: mbj@microsoft.com
URI: http://self-issued.info/
John Bradley
Ping Identity
Email: ve7jtb@ve7jtb.com
Nat Sakimura
Nomura Research Institute
Email: n-sakimura@nri.co.jp
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