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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.
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 (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 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.
1.
Introduction
1.1.
Notational Conventions
2.
Terminology
3.
JSON Web Signature (JWS) Overview
3.1.
Example JWS
4.
JWS Header
4.1.
Reserved Header Parameter Names
4.1.1.
"alg" (Algorithm) Header Parameter
4.1.2.
"jku" (JWK Set URL) Header Parameter
4.1.3.
"jwk" (JSON Web Key) Header Parameter
4.1.4.
"x5u" (X.509 URL) Header Parameter
4.1.5.
"x5t" (X.509 Certificate Thumbprint) Header Parameter
4.1.6.
"x5c" (X.509 Certificate Chain) Header Parameter
4.1.7.
"kid" (Key ID) Header Parameter
4.1.8.
"typ" (Type) Header Parameter
4.1.9.
"cty" (Content Type) Header Parameter
4.1.10.
"crit" (Critical) Header Parameter
4.2.
Public Header Parameter Names
4.3.
Private Header Parameter Names
5.
Producing and Consuming JWSs
5.1.
Message Signing or MACing
5.2.
Message Signature or MAC Validation
5.3.
String Comparison Rules
6.
Key Identification
7.
Serializations
7.1.
JWS Compact Serialization
7.2.
JWS JSON Serialization
8.
IANA Considerations
8.1.
JSON Web Signature and Encryption Header Parameters Registry
8.1.1.
Registration Template
8.1.2.
Initial Registry Contents
8.2.
JSON Web Signature and Encryption Type Values Registry
8.2.1.
Registration Template
8.2.2.
Initial Registry Contents
8.3.
Media Type Registration
8.3.1.
Registry Contents
9.
Security Considerations
9.1.
Cryptographic Security Considerations
9.2.
JSON Security Considerations
9.3.
Unicode Comparison Security Considerations
9.4.
TLS Requirements
10.
References
10.1.
Normative References
10.2.
Informative References
Appendix A.
JWS Examples
A.1.
Example JWS using HMAC SHA-256
A.1.1.
Encoding
A.1.2.
Decoding
A.1.3.
Validating
A.2.
Example JWS using RSASSA-PKCS-v1_5 SHA-256
A.2.1.
Encoding
A.2.2.
Decoding
A.2.3.
Validating
A.3.
Example JWS using ECDSA P-256 SHA-256
A.3.1.
Encoding
A.3.2.
Decoding
A.3.3.
Validating
A.4.
Example JWS using ECDSA P-521 SHA-512
A.4.1.
Encoding
A.4.2.
Decoding
A.4.3.
Validating
A.5.
Example Plaintext JWS
A.6.
Example JWS Using JWS JSON Serialization
A.6.1.
JWS Protected Header
A.6.2.
JWS Per-Signature Unprotected Headers
A.6.3.
Complete JWS Header Values
A.6.4.
Complete JWS JSON Serialization Representation
A.6.5.
RSA Key Used for Second Signature
Appendix B.
"x5c" (X.509 Certificate Chain) Example
Appendix C.
Notes on implementing base64url encoding without padding
Appendix D.
Negative Test Case for "crit" Header Parameter
Appendix E.
Acknowledgements
Appendix F.
Document History
§
Authors' Addresses
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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] (Crockford, D., “The application/json Media Type for JavaScript Object Notation (JSON),” July 2006.) 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] (Jones, M., “JSON Web Algorithms (JWA),” July 2013.) specification. Related encryption capabilities are described in the separate JSON Web Encryption (JWE) [JWE] (Jones, M., Rescorla, E., and J. Hildebrand, “JSON Web Encryption (JWE),” July 2013.) specification.
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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] (Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.).
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- 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] (Yergeau, F., “UTF-8, a transformation format of ISO 10646,” November 2003.) encoded text string representing a JSON object; the syntax of JSON objects is defined in Section 2.2 of [RFC4627] (Crockford, D., “The application/json Media Type for JavaScript Object Notation (JSON),” July 2006.).
- 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.
- 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 (Josefsson, S., “The Base16, Base32, and Base64 Data Encodings,” October 2006.) [RFC4648], Section 5, with the (non URL-safe) '=' padding characters omitted, as permitted by Section 3.2. (See Appendix C (Notes on implementing base64url encoding without padding) 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.
- 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] (Leach, P., Mealling, M., and R. Salz, “A Universally Unique IDentifier (UUID) URN Namespace,” July 2005.). 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] (Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” January 2005.). StringOrURI values are compared as case-sensitive strings with no transformations or canonicalizations applied.
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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 (JWS JSON Serialization).
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.
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The following example JWS Header declares that the encoded object is a JSON Web Token (JWT) [JWT] (Jones, M., Bradley, J., and N. Sakimura, “JSON Web Token (JWT),” July 2013.) 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:
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] (American National Standards Institute, “Coded Character Set -- 7-bit American Standard Code for Information Interchange,” 1986.) 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 (Example JWS using HMAC SHA-256) 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 (Example JWS using HMAC SHA-256). See Appendix A (JWS Examples) for additional examples.
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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] (Ecma International, “ECMAScript Language Specification, 5.1 Edition,” June 2011.).
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 ("crit" (Critical) Header Parameter), 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.
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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 (JSON Web Signature and Encryption Header Parameters Registry). 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.
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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] (Jones, M., “JSON Web Algorithms (JWA),” July 2013.) or be a value that contains a Collision Resistant Namespace. The alg value is a case sensitive string 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] (Jones, M., “JSON Web Algorithms (JWA),” July 2013.); the initial contents of this registry are the values defined in Section 3.1 of the JSON Web Algorithms (JWA) [JWA] (Jones, M., “JSON Web Algorithms (JWA),” July 2013.) specification.
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The jku (JWK Set URL) header parameter is a URI [RFC3986] (Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” January 2005.) 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] (Jones, M., “JSON Web Key (JWK),” July 2013.). The protocol used to acquire the resource MUST provide integrity protection; an HTTP GET request to retrieve the JWK Set MUST use TLS [RFC2818] (Rescorla, E., “HTTP Over TLS,” May 2000.) [RFC5246] (Dierks, T. and E. Rescorla, “The Transport Layer Security (TLS) Protocol Version 1.2,” August 2008.); the identity of the server MUST be validated, as per Section 3.1 of HTTP Over TLS [RFC2818] (Rescorla, E., “HTTP Over TLS,” May 2000.). Use of this header parameter is OPTIONAL.
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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] (Jones, M., “JSON Web Key (JWK),” July 2013.). Use of this header parameter is OPTIONAL.
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The x5u (X.509 URL) header parameter is a URI [RFC3986] (Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” January 2005.) that refers to a resource for the X.509 public key certificate or certificate chain [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,” May 2008.) 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 (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,” May 2008.) [RFC5280] in PEM encoded form [RFC1421] (Linn, J., “Privacy Enhancement for Internet Electronic Mail: Part I: Message Encryption and Authentication Procedures,” February 1993.). 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] (Rescorla, E., “HTTP Over TLS,” May 2000.) [RFC5246] (Dierks, T. and E. Rescorla, “The Transport Layer Security (TLS) Protocol Version 1.2,” August 2008.); the identity of the server MUST be validated, as per Section 3.1 of HTTP Over TLS [RFC2818] (Rescorla, E., “HTTP Over TLS,” May 2000.). Use of this header parameter is OPTIONAL.
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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] (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,” May 2008.) 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 (JSON Web Signature and Encryption Header Parameters Registry).
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The x5c (X.509 Certificate Chain) header parameter contains the X.509 public key certificate or certificate chain [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,” May 2008.) 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] (Josefsson, S., “The Base16, Base32, and Base64 Data Encodings,” October 2006.) Section 4 -- not base64url encoded) DER [ITU.X690.1994] (International Telecommunications Union, “Information Technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER),” 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] (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,” May 2008.) and reject the JWS if any validation failure occurs. Use of this header parameter is OPTIONAL.
See Appendix B ("x5c" (X.509 Certificate Chain) Example) for an example x5c value.
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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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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] (Freed, N. and N. Borenstein, “Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types,” November 1996.) 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 (JSON Web Signature and Encryption Type Values Registry) or be a value that contains a Collision Resistant Namespace.
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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.
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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] (Jones, M., “JSON Web Algorithms (JWA),” July 2013.) 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] (Jones, M., “JSON Web Algorithms (JWA),” July 2013.) for use with JWS, or any other constraints on its use are 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
}
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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 (JSON Web Signature and Encryption Header Parameters Registry) 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.
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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 (Reserved Header Parameter Names) or Public Names Section 4.2 (Public Header Parameter Names). Unlike Public Names, Private Names are subject to collision and should be used with caution.
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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.
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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.
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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:
Also, see the JSON security considerations in Section 9.2 (JSON Security Considerations) and the Unicode security considerations in Section 9.3 (Unicode Comparison Security Considerations).
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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 (Reserved Header Parameter Names) 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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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.
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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.
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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:
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 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 (Example JWS Using JWS JSON Serialization) for an example of computing a JWS using the JWS JSON Serialization.
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The following registration procedure is used for all the registries established by this specification.
Values are registered with a Specification Required [RFC5226] (Narten, T. and H. Alvestrand, “Guidelines for Writing an IANA Considerations Section in RFCs,” May 2008.) 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.
IANA must only accept registry updates from the Designated Expert(s) and should direct all requests for registration to the review mailing list.
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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.
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- 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.
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This specification registers the Header Parameter Names defined in Section 4.1 (Reserved Header Parameter Names) in this registry.
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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] (Freed, N. and N. Borenstein, “Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types,” November 1996.) 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] (Freed, N. and N. Borenstein, “Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types,” November 1996.) values MUST NOT be directly registered as new typ values; rather, new typ values MAY be registered as short names for MIME types.
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- "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.
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This specification registers the JOSE and JOSE+JSON type values in this registry:
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This specification registers the application/jose Media Type [RFC2046] (Freed, N. and N. Borenstein, “Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types,” November 1996.) in the MIME Media Type registry [RFC4288] (Freed, N. and J. Klensin, “Media Type Specifications and Registration Procedures,” December 2005.), 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.
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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 (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,” January 2012.) [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 (Datta, P. and F. Hirsch, “XML Signature Best Practices,” August 2011.) [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.
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.
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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] (Crockford, D., “The application/json Media Type for JavaScript Object Notation (JSON),” July 2006.) 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] (Ecma International, “ECMAScript Language Specification, 5.1 Edition,” June 2011.)". 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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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 (Crockford, D., “The application/json Media Type for JavaScript Object Notation (JSON),” July 2006.) [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.
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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] (Dierks, T. and E. Rescorla, “The Transport Layer Security (TLS) Protocol Version 1.2,” August 2008.) 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] (Dierks, T. and C. Allen, “The TLS Protocol Version 1.0,” January 1999.) 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 (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),” March 2011.) [RFC6125].
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| [ECMAScript] | Ecma International, “ECMAScript Language Specification, 5.1 Edition,” ECMA 262, June 2011 (HTML, PDF). |
| [ITU.X690.1994] | International Telecommunications Union, “Information 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 (HTML). |
| [JWK] | Jones, M., “JSON Web Key (JWK),” draft-ietf-jose-json-web-key (work in progress), July 2013 (HTML). |
| [RFC1421] | Linn, J., “Privacy Enhancement for Internet Electronic Mail: Part I: Message Encryption and Authentication Procedures,” RFC 1421, February 1993 (TXT). |
| [RFC2046] | Freed, N. and N. Borenstein, “Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types,” RFC 2046, November 1996 (TXT). |
| [RFC2119] | Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” BCP 14, RFC 2119, March 1997 (TXT, HTML, XML). |
| [RFC2246] | Dierks, T. and C. Allen, “The TLS Protocol Version 1.0,” RFC 2246, January 1999 (TXT). |
| [RFC2818] | Rescorla, E., “HTTP Over TLS,” RFC 2818, May 2000 (TXT). |
| [RFC3629] | Yergeau, F., “UTF-8, a transformation format of ISO 10646,” STD 63, RFC 3629, November 2003 (TXT). |
| [RFC3986] | Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” STD 66, RFC 3986, January 2005 (TXT, HTML, XML). |
| [RFC4288] | Freed, N. and J. Klensin, “Media Type Specifications and Registration Procedures,” RFC 4288, December 2005 (TXT). |
| [RFC4627] | Crockford, D., “The application/json Media Type for JavaScript Object Notation (JSON),” RFC 4627, July 2006 (TXT). |
| [RFC4648] | Josefsson, S., “The Base16, Base32, and Base64 Data Encodings,” RFC 4648, October 2006 (TXT). |
| [RFC5226] | Narten, T. and H. Alvestrand, “Guidelines for Writing an IANA Considerations Section in RFCs,” BCP 26, RFC 5226, May 2008 (TXT). |
| [RFC5246] | Dierks, T. and E. Rescorla, “The Transport Layer Security (TLS) Protocol Version 1.2,” RFC 5246, August 2008 (TXT). |
| [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 (TXT). |
| [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 (TXT). |
| [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 (HTML). |
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| [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 (HTML). |
| [JWT] | Jones, M., Bradley, J., and N. Sakimura, “JSON Web Token (JWT),” draft-ietf-oauth-json-web-token (work in progress), July 2013 (HTML). |
| [MagicSignatures] | Panzer (editor), J., Laurie, B., and D. Balfanz, “Magic Signatures,” January 2011. |
| [RFC4122] | Leach, P., Mealling, M., and R. Salz, “A Universally Unique IDentifier (UUID) URN Namespace,” RFC 4122, July 2005 (TXT, HTML, XML). |
| [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 (HTML). |
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This section provides several examples of JWSs. While these examples all represent JSON Web Tokens (JWTs) [JWT] (Jones, M., Bradley, J., and N. Sakimura, “JSON Web Token (JWT),” July 2013.), the payload can be any base64url encoded content.
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The following example JWS Header declares that the data structure is a JSON Web Token (JWT) [JWT] (Jones, M., Bradley, J., and N. Sakimura, “JSON Web Token (JWT),” July 2013.) 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 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] (Jones, M., “JSON Web Key (JWK),” July 2013.) 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:
[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
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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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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.
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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]
This example uses the RSA key represented in JSON Web Key [JWK] (Jones, M., “JSON Web Key (JWK),” July 2013.) 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):
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
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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.
| TOC |
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.
| TOC |
| TOC |
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 [JWK] (Jones, M., “JSON Web Key (JWK),” July 2013.) 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 Name | Value |
|---|---|
| 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
| TOC |
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.
| TOC |
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] (Jones, M., “JSON Web Algorithms (JWA),” July 2013.) 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.
| TOC |
| TOC |
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:
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] (Jones, M., “JSON Web Key (JWK),” July 2013.) 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:
| Result Name | Value |
|---|---|
| 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
| TOC |
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.
| TOC |
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] (Jones, M., “JSON Web Algorithms (JWA),” July 2013.) 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.
| TOC |
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):
eyJhbGciOiJub25lIn0 . eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt cGxlLmNvbS9pc19yb290Ijp0cnVlfQ .
| TOC |
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 (Example JWS using RSASSA-PKCS-v1_5 SHA-256) (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 (Example JWS using RSASSA-PKCS-v1_5 SHA-256), 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 (RSA Key Used for Second Signature); 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.
| TOC |
The JWS Protected Header value used for both computations is:
{"alg":"RS256"}
Base64url encoding these octets yields this Encoded JWS Header value:
eyJhbGciOiJSUzI1NiJ9
| TOC |
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"}
| TOC |
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"}
| TOC |
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"}]
}
| TOC |
The second signature in this example uses the RSA key represented in JSON Web Key [JWK] (Jones, M., “JSON Web Key (JWK),” July 2013.) 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"
}
| TOC |
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 ("x5c" (X.509 Certificate Chain) Header Parameter). Note that since these strings contain base64 encoded (not base64url encoded) values, they are allowed to contain white space and line breaks.
["MIIE3jCCA8agAwIBAgICAwEwDQYJKoZIhvcNAQEFBQAwYzELMAkGA1UEBhMCVVM
xITAfBgNVBAoTGFRoZSBHbyBEYWRkeSBHcm91cCwgSW5jLjExMC8GA1UECxMoR2
8gRGFkZHkgQ2xhc3MgMiBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eTAeFw0wNjExM
TYwMTU0MzdaFw0yNjExMTYwMTU0MzdaMIHKMQswCQYDVQQGEwJVUzEQMA4GA1UE
CBMHQXJpem9uYTETMBEGA1UEBxMKU2NvdHRzZGFsZTEaMBgGA1UEChMRR29EYWR
keS5jb20sIEluYy4xMzAxBgNVBAsTKmh0dHA6Ly9jZXJ0aWZpY2F0ZXMuZ29kYW
RkeS5jb20vcmVwb3NpdG9yeTEwMC4GA1UEAxMnR28gRGFkZHkgU2VjdXJlIENlc
nRpZmljYXRpb24gQXV0aG9yaXR5MREwDwYDVQQFEwgwNzk2OTI4NzCCASIwDQYJ
KoZIhvcNAQEBBQADggEPADCCAQoCggEBAMQt1RWMnCZM7DI161+4WQFapmGBWTt
wY6vj3D3HKrjJM9N55DrtPDAjhI6zMBS2sofDPZVUBJ7fmd0LJR4h3mUpfjWoqV
Tr9vcyOdQmVZWt7/v+WIbXnvQAjYwqDL1CBM6nPwT27oDyqu9SoWlm2r4arV3aL
GbqGmu75RpRSgAvSMeYddi5Kcju+GZtCpyz8/x4fKL4o/K1w/O5epHBp+YlLpyo
7RJlbmr2EkRTcDCVw5wrWCs9CHRK8r5RsL+H0EwnWGu1NcWdrxcx+AuP7q2BNgW
JCJjPOq8lh8BJ6qf9Z/dFjpfMFDniNoW1fho3/Rb2cRGadDAW/hOUoz+EDU8CAw
EAAaOCATIwggEuMB0GA1UdDgQWBBT9rGEyk2xF1uLuhV+auud2mWjM5zAfBgNVH
SMEGDAWgBTSxLDSkdRMEXGzYcs9of7dqGrU4zASBgNVHRMBAf8ECDAGAQH/AgEA
MDMGCCsGAQUFBwEBBCcwJTAjBggrBgEFBQcwAYYXaHR0cDovL29jc3AuZ29kYWR
keS5jb20wRgYDVR0fBD8wPTA7oDmgN4Y1aHR0cDovL2NlcnRpZmljYXRlcy5nb2
RhZGR5LmNvbS9yZXBvc2l0b3J5L2dkcm9vdC5jcmwwSwYDVR0gBEQwQjBABgRVH
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| TOC |
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 '=' 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
| TOC |
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.
| TOC |
Solutions for signing JSON content were previously explored by Magic Signatures (Panzer (editor), J., Laurie, B., and D. Balfanz, “Magic Signatures,” January 2011.) [MagicSignatures], JSON Simple Sign (Bradley, J. and N. Sakimura (editor), “JSON Simple Sign,” September 2010.) [JSS], and Canvas Applications (Facebook, “Canvas Applications,” 2010.) [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, 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.
| TOC |
[[ to be removed by the RFC editor before publication as an RFC ]]
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| TOC |
| 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 |