| JOSE Working Group | M.B. Jones |
| Internet-Draft | Microsoft |
| Intended status: Standards Track | E. Rescorla |
| Expires: October 28, 2013 | RTFM |
| J. Hildebrand | |
| Cisco | |
| April 26, 2013 |
JSON Web Encryption (JWE)
draft-ietf-jose-json-web-encryption-10
JSON Web Encryption (JWE) is a means of representing encrypted content using JavaScript Object Notation (JSON) data structures. Cryptographic algorithms and identifiers for use with this specification are described in the separate JSON Web Algorithms (JWA) specification. Related digital signature and MAC capabilities are described in the separate JSON Web Signature (JWS) specification.
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JSON Web Encryption (JWE) is a compact encryption format intended for space constrained environments such as HTTP Authorization headers and URI query parameters. It represents this content using JavaScript Object Notation (JSON) [RFC4627] based data structures. The JWE cryptographic mechanisms encrypt and provide integrity protection for arbitrary sequences of octets.
Cryptographic algorithms and identifiers for use with this specification are described in the separate JSON Web Algorithms (JWA) [JWA] specification. Related digital signature and MAC capabilities are described in the separate JSON Web Signature (JWS) [JWS] specification.
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].
JWE represents encrypted content using JSON data structures and base64url encoding. Five values are represented in a JWE: the JWE Header, the JWE Encrypted Key, the JWE Initialization Vector, the JWE Ciphertext, and the JWE Authentication Tag. In the Compact Serialization, the five values are base64url-encoded for transmission, and represented as the concatenation of the encoded strings in that order, with the five strings being separated by four period ('.') characters. A JSON Serialization for this information is also defined in Section 7.
JWE utilizes authenticated encryption to ensure the confidentiality and integrity of the Plaintext.
This example encrypts the plaintext "The true sign of intelligence is not knowledge but imagination." to the recipient using RSAES OAEP and AES GCM.
The following example JWE Header declares that:
{"alg":"RSA-OAEP","enc":"A256GCM"}
Base64url encoding the octets of the UTF-8 representation of the JWE Header yields this Encoded JWE Header value:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ
The remaining steps to finish creating this JWE are:
The final result in this example (with line breaks for display purposes only) is:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ. ApfOLCaDbqs_JXPYy2I937v_xmrzj-Iss1mG6NAHmeJViM6j2l0MHvfseIdHVyU2 BIoGVu9ohvkkWiRq5DL2jYZTPA9TAdwq3FUIVyoH-Pedf6elHIVFi2KGDEspYMtQ ARMMSBcS7pslx6flh1Cfh3GBKysztVMEhZ_maFkm4PYVCsJsvq6Ct3fg2CJPOs0X 1DHuxZKoIGIqcbeK4XEO5a0h5TAuJObKdfO0dKwfNSSbpu5sFrpRFwV2FTTYoqF4 zI46N9-_hMIznlEpftRXhScEJuZ9HG8C8CHB1WRZ_J48PleqdhF4o7fB5J1wFqUX BtbtuGJ_A2Xe6AEhrlzCOw. 48V1_ALb6US04U3b. 5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji SdiwkIr3ajwQzaBtQD_A. ghEgxninkHEAMp4xZtB2mA
See Appendix A.1 for the complete details of computing this JWE.
This example encrypts the plaintext "Live long and prosper." to the recipient using RSAES-PKCS1-V1_5 and AES_128_CBC_HMAC_SHA_256.
The following example JWE Header (with line breaks for display purposes only) declares that:
{"alg":"RSA1_5","enc":"A128CBC-HS256"}
Base64url encoding the octets of the UTF-8 representation of the JWE Header yields this Encoded JWE Header value:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDK0hTMjU2In0
The remaining steps to finish creating this JWE are the same as for the previous example, but using RSAES-PKCS1-v1_5 instead of RSAES OAEP and using the AES_128_CBC_HMAC_SHA_256 algorithm (which is specified in Sections 4.8 and 4.8.3 of JWA) instead of AES GCM.
The final result in this example (with line breaks for display purposes only) is:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0. nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMkmOm kkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZjDYENR WiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfEJmNmfsx5f cB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWyEHW6WzQ4iH9S IcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_NSsx24LxtK6fIkej RlMBmCfxv0Tg8CtxpURigg. AxY8DCtDaGlsbGljb3RoZQ. KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY. fY2U_Hx5VcfXmipEldHhMA
See Appendix A.2 for the complete details of computing this JWE.
The members of the JSON object represented by the JWE Header describe the encryption applied to the Plaintext and optionally additional properties of the JWE. The Header Parameter Names within this object MUST be unique; JWEs with duplicate Header Parameter Names MUST be rejected.
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 4.1.15, all other header parameters MUST be ignored when not understood.
There are two ways of distinguishing whether a header is a JWS Header or a JWE Header. The first is by examining the alg (algorithm) header parameter value. If the value represents a digital signature or MAC algorithm, or is the value none, it is for a JWS; if it represents a Key Encryption, Key Wrapping, Direct Key Agreement, Key Agreement with Key Wrapping, or Direct Encryption algorithm, it is for a JWE. A second method is determining whether an enc (encryption method) member exists. If the enc member exists, it is a JWE; otherwise, it is a JWS. Both methods will yield the same result for all legal input values.
There are three classes of Header Parameter Names: Reserved Header Parameter Names, Public Header Parameter Names, and Private 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 JWE Compact Serialization to be compact.
Additional reserved Header Parameter Names MAY be defined via the IANA JSON Web Signature and Encryption Header Parameters registry [JWS]. 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.
The alg (algorithm) header parameter identifies the cryptographic algorithm used to encrypt or determine the value of the Content Encryption Key (CEK). The algorithm specified by the alg value MUST be supported by the implementation and there MUST be a key for use with that algorithm associated with the intended recipient or the JWE MUST be rejected. 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 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 4.1 of the JSON Web Algorithms (JWA) [JWA] specification.
The enc (encryption method) header parameter identifies the block encryption algorithm used to encrypt the Plaintext to produce the Ciphertext. This algorithm MUST be an Authenticated Encryption algorithm with a specified key length. The algorithm specified by the enc value MUST be supported by the implementation or the JWE MUST be rejected. enc 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 enc 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 enc 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 4.2 of the JSON Web Algorithms (JWA) [JWA] specification.
The epk (ephemeral public key) value created by the originator for the use in key agreement algorithms. This key is represented as a JSON Web Key [JWK] value. Use of this header parameter is OPTIONAL, although its use is REQUIRED with some alg algorithms. When its use is REQUIRED, this header parameter MUST be understood by implementations.
The zip (compression algorithm) applied to the Plaintext before encryption, if any. If present, the value of the zip header parameter MUST be the case sensitive string "DEF". Compression is performed with the DEFLATE [RFC1951] algorithm. If no zip parameter is present, no compression is applied to the Plaintext before encryption. Use of this header parameter is OPTIONAL. This header parameter MUST be understood by implementations.
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 is the key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE. 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 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.
The jwk (JSON Web Key) header parameter is the public key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE. This key is represented as a JSON Web Key [JWK]. Use of this header parameter is OPTIONAL.
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] containing the key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE. 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 to which the JWE was encrypted 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.
The x5t (X.509 Certificate Thumbprint) header parameter provides a base64url encoded SHA-1 thumbprint (a.k.a. digest) of the DER encoding of the X.509 certificate [RFC5280] containing the key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE. 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 [JWS].
The x5c (X.509 Certificate Chain) header parameter contains the X.509 public key certificate or certificate chain [RFC5280] containing the key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE. The certificate or certificate chain is represented as an array of certificate value strings. Each string is a base64 encoded ([RFC4648] Section 4 -- not base64url encoded) DER [ITU.X690.1994] PKIX certificate value. The certificate containing the public key to which the JWE was encrypted 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. Use of this header parameter is OPTIONAL.
See Appendix B of [JWS] for an example x5c value.
The kid (key ID) header parameter is a hint indicating which key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE. 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.
The typ (type) header parameter is used to declare the type of this object. The type value JWE is used to indicate that this object is a JWE using the JWE Compact Serialization. The type value JWE-JS is used to indicate that this object is a JWE using the JWE JSON Serialization. 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 [JWS] or be a value that contains a Collision Resistant Namespace.
The cty (content type) header parameter is used to declare the type of the encrypted content (the Plaintext). For example, the JSON Web Token (JWT) [JWT] specification uses the cty value JWT to indicate that the Plaintext is a JSON Web Token (JWT). 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.
The apu (agreement PartyUInfo) value for key agreement algorithms using it (such as ECDH-ES), represented as a base64url encoded string. Use of this header parameter is OPTIONAL. When the alg value used identifies an algorithm for which apu is a parameter, this header parameter MUST be understood by implementations.
The apv (agreement PartyVInfo) value for key agreement algorithms using it (such as ECDH-ES), represented as a base64url encoded string. Use of this header parameter is OPTIONAL. When the alg value used identifies an algorithm for which apv is a parameter, this header parameter MUST be understood by implementations.
The crit (critical) header parameter is array listing the names of header parameters that are present in the JWE Header that MUST be understood and processed by the implementation or if not understood, MUST cause the JWE to be rejected. This list MUST NOT include header parameters defined by this specification, duplicate names, or names that do not occur as header parameters within the JWE. 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":"RSA-OAEP",
"enc":"A256GCM",
"crit":["exp"],
"exp":1363284000
}
Additional Header Parameter Names can be defined by those using JWEs. 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 [JWS] 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 JWEs.
A producer and consumer of a JWE 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.
The message encryption process is as follows. The order of the steps is not significant in cases where there are no dependencies between the inputs and outputs of the steps.
The message decryption process is the reverse of the encryption process. 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 these steps fails, the JWE MUST be rejected.
Processing a JWE inevitably requires comparing known strings to values in JSON objects. For example, in checking what the encryption method is, the Unicode string encoding enc will be checked against the member names in the JWE Header to see if there is a matching Header Parameter Name.
Comparisons between JSON strings and other Unicode strings MUST be performed by comparing Unicode code points without normalization as specified in the String Comparison Rules in Section 5.3 of [JWS].
JWE uses cryptographic algorithms to encrypt the Plaintext and the Content Encryption Key (CEK) and to provide integrity protection for the JWE Header, JWE Encrypted Key, and JWE Ciphertext. The JSON Web Algorithms (JWA) [JWA] specification specifies a set of cryptographic algorithms and identifiers to be used with this specification and defines registries for additional such algorithms. Specifically, Section 4.1 specifies a set of alg (algorithm) header parameter values and Section 4.2 specifies a set of enc (encryption method) header parameter values intended for use this specification. It also describes the semantics and operations that are specific to these algorithms.
Public keys employed for encryption can be identified using the Header Parameter methods described in Section 4.1 or can be distributed using methods that are outside the scope of this specification.
JWE supports three forms of Content Encryption Key (CEK) encryption: enc usage in the IANA JSON Web Signature and Encryption Algorithms registry [JWA] and Section 4.1 of the JSON Web Algorithms (JWA) [JWA] specification for lists of encryption algorithms that can be used for CEK encryption.
See the algorithms registered for
The JWE JSON Serialization represents encrypted content as a JSON object with a recipients member containing an array of per-recipient information, an initialization_vector member containing a shared Encoded JWE Initialization Vector value, a ciphertext member containing a shared Encoded JWE Ciphertext value, and an authentication_tag member containing a shared Encoded JWE Authentication Tag value. Each member of the recipients array is a JSON object with a header member containing an Encoded JWE Header value and an encrypted_key member containing an Encoded JWE Encrypted Key value.
Unlike the JWE Compact Serialization, content using the JWE JSON Serialization MAY be encrypted to more than one recipient. Each recipient requires:
Therefore, the syntax is:
{"recipients":[
{"header":"<header 1 contents>",
"encrypted_key":"<encrypted key 1 contents>"},
...
{"header":"<header N contents>",
"encrypted_key":"<encrypted key N contents>"}],
"initialization_vector":"<initialization vector contents>",
"ciphertext":"<ciphertext contents>",
"authentication_tag":"<authentication tag contents>"
}
The contents of the Encoded JWE Header, Encoded JWE Encrypted Key, Encoded JWE Initialization Vector, Encoded JWE Ciphertext, and Encoded JWE Authentication Tag values are exactly as specified in the rest of this specification. They are interpreted and validated in the same manner, with each corresponding header and encrypted_key value being created and validated together.
All recipients use the same JWE Ciphertext, JWE Initialization Vector, and JWE Authentication Tag values, resulting in potentially significant space savings if the message is large. Therefore, all header parameters that specify the treatment of the JWE Ciphertext value MUST be the same for all recipients. This primarily means that the enc (encryption method) header parameter value in the JWE Header for each recipient MUST be the same.
This section contains an example using the JWE JSON Serialization. This example demonstrates the capability for encrypting the same plaintext to multiple recipients.
Two recipients are present in this example: the first using the RSAES-PKCS1-V1_5 algorithm to encrypt the Content Encryption Key (CEK) and the second using RSAES OAEP to encrypt the CEK. The Plaintext is encrypted using the AES_128_CBC_HMAC_SHA_256 algorithm and the same block encryption parameters to produce the common JWE Ciphertext value. The two Decoded JWE Header Segments used are:
{"alg":"RSA1_5","enc":"A128CBC-HS256"}
and:
{"alg":"RSA-OAEP","enc":"A128CBC-HS256"}
The keys used for the first recipient are the same as those in Appendix A.2, as is the Plaintext used. The encryption key used for the second recipient is the same as that used in Appendix A.3; the block encryption keys and parameters for the second recipient are the same as those for the first recipient (which must be the case, since the Initialization Vector and Ciphertext are shared). Thus, the same two Encoded JWE Header and JWE Encoded Encrypted Key values are used in this example as are used in those examples.
The value X used as part of the AAD value is the concatenation of the Encoded JWE Header values, separated by a tilde ('~') character. In this example, the value of X (with line breaks for display purposes only) is:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0 ~ eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0
The value Y used as part of the AAD value is the concatenation of the Encoded JWE Encrypted Key values, separated by a tilde ('~') character. In this example, the value of Y (with line breaks for display purposes only) is:
nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMk mOmkkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZ jDYENRWiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfE JmNmfsx5fcB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWy EHW6WzQ4iH9SIcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_N Ssx24LxtK6fIkejRlMBmCfxv0Tg8CtxpURigg ~ 6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ
The AAD value used for the block encryption is the octets of the ASCII representation of the concatenation of X, a period ('.') character, and Y. This concatenation (with line breaks for display purposes only) is:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0 ~ eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0 . nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMk mOmkkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZ jDYENRWiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfE JmNmfsx5fcB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWy EHW6WzQ4iH9SIcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_N Ssx24LxtK6fIkejRlMBmCfxv0Tg8CtxpURigg ~ 6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ
The complete JSON Web Encryption JSON Serialization (JWE-JS) for these values is as follows (with line breaks for display purposes only):
{"recipients":[
{"header":
"eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0",
"encrypted_key":
"nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMk
mOmkkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZ
jDYENRWiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfE
JmNmfsx5fcB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWy
EHW6WzQ4iH9SIcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_N
Ssx24LxtK6fIkejRlMBmCfxv0Tg8CtxpURigg"},
{"header":
"eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0",
"encrypted_key":
"6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ"}],
"initialization_vector":
"AxY8DCtDaGlsbGljb3RoZQ",
"ciphertext":
"KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY",
"authentication_tag":
"LlhRZFfphc2f5X3nTTJP6g"
}
The JWE Compact Serialization is mandatory to implement. Implementation of the JWE JSON Serialization is OPTIONAL.
This specification registers the Header Parameter Names defined in Section 4.1 in the IANA JSON Web Signature and Encryption Header Parameters registry [JWS].
This specification registers the JWE and JWE-JS type values in the IANA JSON Web Signature and Encryption Type Values registry [JWS]:
This specification registers the application/jwe and application/jwe-js Media Types [RFC2046] in the MIME Media Type registry [RFC4288] to indicate, respectively, that the content is a JWE using the JWE Compact Serialization or a JWE using the JWE JSON Serialization.
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.
All the security considerations in the JWS specification also apply to this specification. Likewise, all the security considerations in XML Encryption 1.1 [W3C.CR-xmlenc-core1-20120313] also apply, other than those that are XML specific.
When decrypting, particular care must be taken not to allow the JWE recipient to be used as an oracle for decrypting messages. RFC 3218 [RFC3218] should be consulted for specific countermeasures to attacks on RSAES-PKCS1-V1_5. An attacker might modify the contents of the alg parameter from RSA-OAEP to RSA1_5 in order to generate a formatting error that can be detected and used to recover the CEK even if RSAES OAEP was used to encrypt the CEK. It is therefore particularly important to report all formatting errors to the CEK, Additional Authenticated Data, or ciphertext as a single error when the JWE is rejected.
| [RFC3218] | Rescorla, E., "Preventing the Million Message Attack on Cryptographic Message Syntax", RFC 3218, January 2002. |
| [RFC4122] | Leach, P., Mealling, M. and R. Salz, "A Universally Unique IDentifier (UUID) URN Namespace", RFC 4122, July 2005. |
| [RFC5652] | Housley, R., "Cryptographic Message Syntax (CMS)", STD 70, RFC 5652, September 2009. |
| [I-D.rescorla-jsms] | Rescorla, E. and J. Hildebrand, "JavaScript Message Security Format", Internet-Draft draft-rescorla-jsms-00, March 2011. |
| [I-D.mcgrew-aead-aes-cbc-hmac-sha2] | McGrew, D. and K. Paterson, "Authenticated Encryption with AES-CBC and HMAC-SHA", Internet-Draft draft-mcgrew-aead-aes-cbc-hmac-sha2-01, October 2012. |
| [JWT] | Jones, M.B., Bradley, J. and N. Sakimura, "JSON Web Token (JWT)", Internet-Draft draft-ietf-oauth-json-web-token, April 2013. |
| [JSE] | Bradley, J. and N. Sakimura (editor), "JSON Simple Encryption", September 2010. |
This section provides examples of JWE computations.
This example encrypts the plaintext "The true sign of intelligence is not knowledge but imagination." to the recipient using RSAES OAEP and AES GCM. The representation of this plaintext is:
[84, 104, 101, 32, 116, 114, 117, 101, 32, 115, 105, 103, 110, 32, 111, 102, 32, 105, 110, 116, 101, 108, 108, 105, 103, 101, 110, 99, 101, 32, 105, 115, 32, 110, 111, 116, 32, 107, 110, 111, 119, 108, 101, 100, 103, 101, 32, 98, 117, 116, 32, 105, 109, 97, 103, 105, 110, 97, 116, 105, 111, 110, 46]
The following example JWE Header declares that:
{"alg":"RSA-OAEP","enc":"A256GCM"}
Base64url encoding the octets of the UTF-8 representation of the JWE Header yields this Encoded JWE Header value:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ
Generate a 256 bit random Content Encryption Key (CEK). In this example, the value is:
[177, 161, 244, 128, 84, 143, 225, 115, 63, 180, 3, 255, 107, 154, 212, 246, 138, 7, 110, 91, 112, 46, 34, 105, 47, 130, 203, 46, 122, 234, 64, 252]
Encrypt the CEK with the recipient's public key using the RSAES OAEP algorithm to produce the JWE Encrypted Key. In this example, the RSA key parameters are:
| Parameter Name | Value |
|---|---|
| Modulus | [161, 168, 84, 34, 133, 176, 208, 173, 46, 176, 163, 110, 57, 30, 135, 227, 9, 31, 226, 128, 84, 92, 116, 241, 70, 248, 27, 227, 193, 62, 5, 91, 241, 145, 224, 205, 141, 176, 184, 133, 239, 43, 81, 103, 9, 161, 153, 157, 179, 104, 123, 51, 189, 34, 152, 69, 97, 69, 78, 93, 140, 131, 87, 182, 169, 101, 92, 142, 3, 22, 167, 8, 212, 56, 35, 79, 210, 222, 192, 208, 252, 49, 109, 138, 173, 253, 210, 166, 201, 63, 102, 74, 5, 158, 41, 90, 144, 108, 160, 79, 10, 89, 222, 231, 172, 31, 227, 197, 0, 19, 72, 81, 138, 78, 136, 221, 121, 118, 196, 17, 146, 10, 244, 188, 72, 113, 55, 221, 162, 217, 171, 27, 57, 233, 210, 101, 236, 154, 199, 56, 138, 239, 101, 48, 198, 186, 202, 160, 76, 111, 234, 71, 57, 183, 5, 211, 171, 136, 126, 64, 40, 75, 58, 89, 244, 254, 107, 84, 103, 7, 236, 69, 163, 18, 180, 251, 58, 153, 46, 151, 174, 12, 103, 197, 181, 161, 162, 55, 250, 235, 123, 110, 17, 11, 158, 24, 47, 133, 8, 199, 235, 107, 126, 130, 246, 73, 195, 20, 108, 202, 176, 214, 187, 45, 146, 182, 118, 54, 32, 200, 61, 201, 71, 243, 1, 255, 131, 84, 37, 111, 211, 168, 228, 45, 192, 118, 27, 197, 235, 232, 36, 10, 230, 248, 190, 82, 182, 140, 35, 204, 108, 190, 253, 186, 186, 27] |
| Exponent | [1, 0, 1] |
| Private Exponent | [144, 183, 109, 34, 62, 134, 108, 57, 44, 252, 10, 66, 73, 54, 16, 181, 233, 92, 54, 219, 101, 42, 35, 178, 63, 51, 43, 92, 119, 136, 251, 41, 53, 23, 191, 164, 164, 60, 88, 227, 229, 152, 228, 213, 149, 228, 169, 237, 104, 71, 151, 75, 88, 252, 216, 77, 251, 231, 28, 97, 88, 193, 215, 202, 248, 216, 121, 195, 211, 245, 250, 112, 71, 243, 61, 129, 95, 39, 244, 122, 225, 217, 169, 211, 165, 48, 253, 220, 59, 122, 219, 42, 86, 223, 32, 236, 39, 48, 103, 78, 122, 216, 187, 88, 176, 89, 24, 1, 42, 177, 24, 99, 142, 170, 1, 146, 43, 3, 108, 64, 194, 121, 182, 95, 187, 134, 71, 88, 96, 134, 74, 131, 167, 69, 106, 143, 121, 27, 72, 44, 245, 95, 39, 194, 179, 175, 203, 122, 16, 112, 183, 17, 200, 202, 31, 17, 138, 156, 184, 210, 157, 184, 154, 131, 128, 110, 12, 85, 195, 122, 241, 79, 251, 229, 183, 117, 21, 123, 133, 142, 220, 153, 9, 59, 57, 105, 81, 255, 138, 77, 82, 54, 62, 216, 38, 249, 208, 17, 197, 49, 45, 19, 232, 157, 251, 131, 137, 175, 72, 126, 43, 229, 69, 179, 117, 82, 157, 213, 83, 35, 57, 210, 197, 252, 171, 143, 194, 11, 47, 163, 6, 253, 75, 252, 96, 11, 187, 84, 130, 210, 7, 121, 78, 91, 79, 57, 251, 138, 132, 220, 60, 224, 173, 56, 224, 201] |
The resulting JWE Encrypted Key value is:
[2, 151, 206, 44, 38, 131, 110, 171, 63, 37, 115, 216, 203, 98, 61, 223, 187, 255, 198, 106, 243, 143, 226, 44, 179, 89, 134, 232, 208, 7, 153, 226, 85, 136, 206, 163, 218, 93, 12, 30, 247, 236, 120, 135, 71, 87, 37, 54, 4, 138, 6, 86, 239, 104, 134, 249, 36, 90, 36, 106, 228, 50, 246, 141, 134, 83, 60, 15, 83, 1, 220, 42, 220, 85, 8, 87, 42, 7, 248, 247, 157, 127, 167, 165, 28, 133, 69, 139, 98, 134, 12, 75, 41, 96, 203, 80, 1, 19, 12, 72, 23, 18, 238, 155, 37, 199, 167, 229, 135, 80, 159, 135, 113, 129, 43, 43, 51, 181, 83, 4, 133, 159, 230, 104, 89, 38, 224, 246, 21, 10, 194, 108, 190, 174, 130, 183, 119, 224, 216, 34, 79, 58, 205, 23, 212, 49, 238, 197, 146, 168, 32, 98, 42, 113, 183, 138, 225, 113, 14, 229, 173, 33, 229, 48, 46, 36, 230, 202, 117, 243, 180, 116, 172, 31, 53, 36, 155, 166, 238, 108, 22, 186, 81, 23, 5, 118, 21, 52, 216, 162, 161, 120, 204, 142, 58, 55, 223, 191, 132, 194, 51, 158, 81, 41, 126, 212, 87, 133, 39, 4, 38, 230, 125, 28, 111, 2, 240, 33, 193, 213, 100, 89, 252, 158, 60, 62, 87, 170, 118, 17, 120, 163, 183, 193, 228, 157, 112, 22, 165, 23, 6, 214, 237, 184, 98, 127, 3, 101, 222, 232, 1, 33, 174, 92, 194, 59]
Base64url encode the JWE Encrypted Key to produce the Encoded JWE Encrypted Key. This result (with line breaks for display purposes only) is:
ApfOLCaDbqs_JXPYy2I937v_xmrzj-Iss1mG6NAHmeJViM6j2l0MHvfseIdHVyU2 BIoGVu9ohvkkWiRq5DL2jYZTPA9TAdwq3FUIVyoH-Pedf6elHIVFi2KGDEspYMtQ ARMMSBcS7pslx6flh1Cfh3GBKysztVMEhZ_maFkm4PYVCsJsvq6Ct3fg2CJPOs0X 1DHuxZKoIGIqcbeK4XEO5a0h5TAuJObKdfO0dKwfNSSbpu5sFrpRFwV2FTTYoqF4 zI46N9-_hMIznlEpftRXhScEJuZ9HG8C8CHB1WRZ_J48PleqdhF4o7fB5J1wFqUX BtbtuGJ_A2Xe6AEhrlzCOw
Generate a random 96 bit JWE Initialization Vector. In this example, the value is:
[227, 197, 117, 252, 2, 219, 233, 68, 180, 225, 77, 219]
Base64url encoding this value yields the Encoded JWE Initialization Vector value:
48V1_ALb6US04U3b
Concatenate the Encoded JWE Header value, a period ('.') character, and the Encoded JWE Encrypted Key to create the Additional Authenticated Data parameter. This result (with line breaks for display purposes only) is:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ. ApfOLCaDbqs_JXPYy2I937v_xmrzj-Iss1mG6NAHmeJViM6j2l0MHvfseIdHVyU2 BIoGVu9ohvkkWiRq5DL2jYZTPA9TAdwq3FUIVyoH-Pedf6elHIVFi2KGDEspYMtQ ARMMSBcS7pslx6flh1Cfh3GBKysztVMEhZ_maFkm4PYVCsJsvq6Ct3fg2CJPOs0X 1DHuxZKoIGIqcbeK4XEO5a0h5TAuJObKdfO0dKwfNSSbpu5sFrpRFwV2FTTYoqF4 zI46N9-_hMIznlEpftRXhScEJuZ9HG8C8CHB1WRZ_J48PleqdhF4o7fB5J1wFqUX BtbtuGJ_A2Xe6AEhrlzCOw
The representation of this value is:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 83, 85, 48, 69, 116, 84, 48, 70, 70, 85, 67, 73, 115, 73, 109, 86, 117, 89, 121, 73, 54, 73, 107, 69, 121, 78, 84, 90, 72, 81, 48, 48, 105, 102, 81, 46, 65, 112, 102, 79, 76, 67, 97, 68, 98, 113, 115, 95, 74, 88, 80, 89, 121, 50, 73, 57, 51, 55, 118, 95, 120, 109, 114, 122, 106, 45, 73, 115, 115, 49, 109, 71, 54, 78, 65, 72, 109, 101, 74, 86, 105, 77, 54, 106, 50, 108, 48, 77, 72, 118, 102, 115, 101, 73, 100, 72, 86, 121, 85, 50, 66, 73, 111, 71, 86, 117, 57, 111, 104, 118, 107, 107, 87, 105, 82, 113, 53, 68, 76, 50, 106, 89, 90, 84, 80, 65, 57, 84, 65, 100, 119, 113, 51, 70, 85, 73, 86, 121, 111, 72, 45, 80, 101, 100, 102, 54, 101, 108, 72, 73, 86, 70, 105, 50, 75, 71, 68, 69, 115, 112, 89, 77, 116, 81, 65, 82, 77, 77, 83, 66, 99, 83, 55, 112, 115, 108, 120, 54, 102, 108, 104, 49, 67, 102, 104, 51, 71, 66, 75, 121, 115, 122, 116, 86, 77, 69, 104, 90, 95, 109, 97, 70, 107, 109, 52, 80, 89, 86, 67, 115, 74, 115, 118, 113, 54, 67, 116, 51, 102, 103, 50, 67, 74, 80, 79, 115, 48, 88, 49, 68, 72, 117, 120, 90, 75, 111, 73, 71, 73, 113, 99, 98, 101, 75, 52, 88, 69, 79, 53, 97, 48, 104, 53, 84, 65, 117, 74, 79, 98, 75, 100, 102, 79, 48, 100, 75, 119, 102, 78, 83, 83, 98, 112, 117, 53, 115, 70, 114, 112, 82, 70, 119, 86, 50, 70, 84, 84, 89, 111, 113, 70, 52, 122, 73, 52, 54, 78, 57, 45, 95, 104, 77, 73, 122, 110, 108, 69, 112, 102, 116, 82, 88, 104, 83, 99, 69, 74, 117, 90, 57, 72, 71, 56, 67, 56, 67, 72, 66, 49, 87, 82, 90, 95, 74, 52, 56, 80, 108, 101, 113, 100, 104, 70, 52, 111, 55, 102, 66, 53, 74, 49, 119, 70, 113, 85, 88, 66, 116, 98, 116, 117, 71, 74, 95, 65, 50, 88, 101, 54, 65, 69, 104, 114, 108, 122, 67, 79, 119]
Encrypt the Plaintext with AES GCM using the CEK as the encryption key, the JWE Initialization Vector, and the Additional Authenticated Data value above, requesting a 128 bit Authentication Tag output. The resulting Ciphertext is:
[229, 236, 166, 241, 53, 191, 115, 196, 174, 43, 73, 109, 39, 122, 233, 96, 140, 206, 120, 52, 51, 237, 48, 11, 190, 219, 186, 80, 111, 104, 50, 142, 47, 167, 59, 61, 181, 127, 196, 21, 40, 82, 242, 32, 123, 143, 168, 226, 73, 216, 176, 144, 138, 247, 106, 60, 16, 205, 160, 109, 64, 63, 192]
The resulting Authentication Tag value is:
[130, 17, 32, 198, 120, 167, 144, 113, 0, 50, 158, 49, 102, 208, 118, 152]
Base64url encode the Ciphertext to create the Encoded JWE Ciphertext. This result (with line breaks for display purposes only) is:
5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji SdiwkIr3ajwQzaBtQD_A
Base64url encode the Authentication Tag to create the Encoded JWE Authentication Tag. This result is:
ghEgxninkHEAMp4xZtB2mA
Assemble the final representation: The Compact Serialization of this result is the concatenation of the Encoded JWE Header, the Encoded JWE Encrypted Key, the Encoded JWE Initialization Vector, the Encoded JWE Ciphertext, and the Encoded JWE Authentication Tag in that order, with the five strings being separated by four period ('.') characters.
The final result in this example (with line breaks for display purposes only) is:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ. ApfOLCaDbqs_JXPYy2I937v_xmrzj-Iss1mG6NAHmeJViM6j2l0MHvfseIdHVyU2 BIoGVu9ohvkkWiRq5DL2jYZTPA9TAdwq3FUIVyoH-Pedf6elHIVFi2KGDEspYMtQ ARMMSBcS7pslx6flh1Cfh3GBKysztVMEhZ_maFkm4PYVCsJsvq6Ct3fg2CJPOs0X 1DHuxZKoIGIqcbeK4XEO5a0h5TAuJObKdfO0dKwfNSSbpu5sFrpRFwV2FTTYoqF4 zI46N9-_hMIznlEpftRXhScEJuZ9HG8C8CHB1WRZ_J48PleqdhF4o7fB5J1wFqUX BtbtuGJ_A2Xe6AEhrlzCOw. 48V1_ALb6US04U3b. 5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji SdiwkIr3ajwQzaBtQD_A. ghEgxninkHEAMp4xZtB2mA
This example illustrates the process of creating a JWE with RSA OAEP and AES GCM. These results can be used to validate JWE decryption implementations for these algorithms. Note that since the RSAES OAEP computation includes random values, the encryption results above will not be completely reproducible. However, since the AES GCM computation is deterministic, the JWE Encrypted Ciphertext values will be the same for all encryptions performed using these inputs.
This example encrypts the plaintext "Live long and prosper." to the recipient using RSAES-PKCS1-V1_5 and AES_128_CBC_HMAC_SHA_256. The representation of this plaintext is:
[76, 105, 118, 101, 32, 108, 111, 110, 103, 32, 97, 110, 100, 32, 112, 114, 111, 115, 112, 101, 114, 46]
The following example JWE Header (with line breaks for display purposes only) declares that:
{"alg":"RSA1_5","enc":"A128CBC-HS256"}
Base64url encoding the octets of the UTF-8 representation of the JWE Header yields this Encoded JWE Header value:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0
Generate a 256 bit random Content Encryption Key (CEK). In this example, the key value is:
[4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106, 206, 107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156, 44, 207]
Encrypt the CEK with the recipient's public key using the RSAES-PKCS1-V1_5 algorithm to produce the JWE Encrypted Key. In this example, the RSA key parameters are:
| Parameter Name | Value |
|---|---|
| Modulus | [177, 119, 33, 13, 164, 30, 108, 121, 207, 136, 107, 242, 12, 224, 19, 226, 198, 134, 17, 71, 173, 75, 42, 61, 48, 162, 206, 161, 97, 108, 185, 234, 226, 219, 118, 206, 118, 5, 169, 224, 60, 181, 90, 85, 51, 123, 6, 224, 4, 122, 29, 230, 151, 12, 244, 127, 121, 25, 4, 85, 220, 144, 215, 110, 130, 17, 68, 228, 129, 138, 7, 130, 231, 40, 212, 214, 17, 179, 28, 124, 151, 178, 207, 20, 14, 154, 222, 113, 176, 24, 198, 73, 211, 113, 9, 33, 178, 80, 13, 25, 21, 25, 153, 212, 206, 67, 154, 147, 70, 194, 192, 183, 160, 83, 98, 236, 175, 85, 23, 97, 75, 199, 177, 73, 145, 50, 253, 206, 32, 179, 254, 236, 190, 82, 73, 67, 129, 253, 252, 220, 108, 136, 138, 11, 192, 1, 36, 239, 228, 55, 81, 113, 17, 25, 140, 63, 239, 146, 3, 172, 96, 60, 227, 233, 64, 255, 224, 173, 225, 228, 229, 92, 112, 72, 99, 97, 26, 87, 187, 123, 46, 50, 90, 202, 117, 73, 10, 153, 47, 224, 178, 163, 77, 48, 46, 154, 33, 148, 34, 228, 33, 172, 216, 89, 46, 225, 127, 68, 146, 234, 30, 147, 54, 146, 5, 133, 45, 78, 254, 85, 55, 75, 213, 86, 194, 218, 215, 163, 189, 194, 54, 6, 83, 36, 18, 153, 53, 7, 48, 89, 35, 66, 144, 7, 65, 154, 13, 97, 75, 55, 230, 132, 3, 13, 239, 71] |
| Exponent | [1, 0, 1] |
| Private Exponent | [84, 80, 150, 58, 165, 235, 242, 123, 217, 55, 38, 154, 36, 181, 221, 156, 211, 215, 100, 164, 90, 88, 40, 228, 83, 148, 54, 122, 4, 16, 165, 48, 76, 194, 26, 107, 51, 53, 179, 165, 31, 18, 198, 173, 78, 61, 56, 97, 252, 158, 140, 80, 63, 25, 223, 156, 36, 203, 214, 252, 120, 67, 180, 167, 3, 82, 243, 25, 97, 214, 83, 133, 69, 16, 104, 54, 160, 200, 41, 83, 164, 187, 70, 153, 111, 234, 242, 158, 175, 28, 198, 48, 211, 45, 148, 58, 23, 62, 227, 74, 52, 117, 42, 90, 41, 249, 130, 154, 80, 119, 61, 26, 193, 40, 125, 10, 152, 174, 227, 225, 205, 32, 62, 66, 6, 163, 100, 99, 219, 19, 253, 25, 105, 80, 201, 29, 252, 157, 237, 69, 1, 80, 171, 167, 20, 196, 156, 109, 249, 88, 0, 3, 152, 38, 165, 72, 87, 6, 152, 71, 156, 214, 16, 71, 30, 82, 51, 103, 76, 218, 63, 9, 84, 163, 249, 91, 215, 44, 238, 85, 101, 240, 148, 1, 82, 224, 91, 135, 105, 127, 84, 171, 181, 152, 210, 183, 126, 24, 46, 196, 90, 173, 38, 245, 219, 186, 222, 27, 240, 212, 194, 15, 66, 135, 226, 178, 190, 52, 245, 74, 65, 224, 81, 100, 85, 25, 204, 165, 203, 187, 175, 84, 100, 82, 15, 11, 23, 202, 151, 107, 54, 41, 207, 3, 136, 229, 134, 131, 93, 139, 50, 182, 204, 93, 130, 89] |
The resulting JWE Encrypted Key value is:
[156, 150, 191, 184, 77, 131, 211, 9, 74, 207, 227, 156, 193, 38, 202, 23, 56, 247, 211, 108, 88, 72, 143, 145, 44, 19, 58, 133, 181, 70, 152, 254, 26, 198, 210, 80, 60, 15, 82, 210, 154, 55, 179, 115, 76, 146, 99, 166, 146, 70, 176, 157, 252, 15, 54, 58, 92, 210, 103, 55, 207, 191, 92, 185, 5, 164, 64, 241, 80, 163, 233, 131, 198, 106, 32, 207, 199, 113, 5, 200, 94, 105, 53, 32, 221, 155, 233, 108, 96, 151, 197, 152, 195, 96, 67, 81, 90, 38, 121, 51, 208, 98, 47, 45, 61, 4, 129, 121, 152, 122, 124, 229, 2, 250, 92, 64, 245, 36, 70, 76, 58, 31, 181, 185, 61, 101, 168, 240, 220, 12, 62, 253, 169, 107, 107, 9, 241, 9, 152, 217, 159, 179, 30, 95, 112, 29, 143, 124, 7, 21, 181, 13, 45, 253, 137, 142, 95, 30, 127, 26, 237, 34, 183, 89, 200, 44, 165, 203, 71, 102, 39, 127, 217, 159, 46, 17, 28, 11, 146, 222, 110, 149, 178, 16, 117, 186, 91, 52, 56, 136, 127, 82, 33, 194, 46, 164, 245, 117, 136, 160, 179, 152, 151, 15, 172, 48, 73, 228, 87, 63, 40, 192, 92, 92, 24, 167, 105, 47, 255, 193, 251, 77, 203, 6, 134, 129, 248, 191, 53, 43, 49, 219, 130, 241, 180, 174, 159, 34, 71, 163, 70, 83, 1, 152, 39, 241, 191, 68, 224, 240, 43, 113, 165, 68, 98, 130]
Base64url encode the JWE Encrypted Key to produce the Encoded JWE Encrypted Key. This result (with line breaks for display purposes only) is:
nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMkmOm kkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZjDYENR WiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfEJmNmfsx5f cB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWyEHW6WzQ4iH9S IcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_NSsx24LxtK6fIkej RlMBmCfxv0Tg8CtxpURigg
Generate a random 128 bit JWE Initialization Vector. In this example, the value is:
[3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104, 101]
Base64url encoding this value yields the Encoded JWE Initialization Vector value:
AxY8DCtDaGlsbGljb3RoZQ
Concatenate the Encoded JWE Header value, a period ('.') character, and the Encoded JWE Encrypted Key to create the Additional Authenticated Data parameter. This result (with line breaks for display purposes only) is:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0. nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMkmOm kkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZjDYENR WiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfEJmNmfsx5f cB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWyEHW6WzQ4iH9S IcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_NSsx24LxtK6fIkej RlMBmCfxv0Tg8CtxpURigg
The representation of this value is:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 83, 85, 48, 69, 120, 88, 122, 85, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73, 110, 48, 46, 110, 74, 97, 95, 117, 69, 50, 68, 48, 119, 108, 75, 122, 45, 79, 99, 119, 83, 98, 75, 70, 122, 106, 51, 48, 50, 120, 89, 83, 73, 45, 82, 76, 66, 77, 54, 104, 98, 86, 71, 109, 80, 52, 97, 120, 116, 74, 81, 80, 65, 57, 83, 48, 112, 111, 51, 115, 51, 78, 77, 107, 109, 79, 109, 107, 107, 97, 119, 110, 102, 119, 80, 78, 106, 112, 99, 48, 109, 99, 51, 122, 55, 57, 99, 117, 81, 87, 107, 81, 80, 70, 81, 111, 45, 109, 68, 120, 109, 111, 103, 122, 56, 100, 120, 66, 99, 104, 101, 97, 84, 85, 103, 51, 90, 118, 112, 98, 71, 67, 88, 120, 90, 106, 68, 89, 69, 78, 82, 87, 105, 90, 53, 77, 57, 66, 105, 76, 121, 48, 57, 66, 73, 70, 53, 109, 72, 112, 56, 53, 81, 76, 54, 88, 69, 68, 49, 74, 69, 90, 77, 79, 104, 45, 49, 117, 84, 49, 108, 113, 80, 68, 99, 68, 68, 55, 57, 113, 87, 116, 114, 67, 102, 69, 74, 109, 78, 109, 102, 115, 120, 53, 102, 99, 66, 50, 80, 102, 65, 99, 86, 116, 81, 48, 116, 95, 89, 109, 79, 88, 120, 53, 95, 71, 117, 48, 105, 116, 49, 110, 73, 76, 75, 88, 76, 82, 50, 89, 110, 102, 57, 109, 102, 76, 104, 69, 99, 67, 53, 76, 101, 98, 112, 87, 121, 69, 72, 87, 54, 87, 122, 81, 52, 105, 72, 57, 83, 73, 99, 73, 117, 112, 80, 86, 49, 105, 75, 67, 122, 109, 74, 99, 80, 114, 68, 66, 74, 53, 70, 99, 95, 75, 77, 66, 99, 88, 66, 105, 110, 97, 83, 95, 95, 119, 102, 116, 78, 121, 119, 97, 71, 103, 102, 105, 95, 78, 83, 115, 120, 50, 52, 76, 120, 116, 75, 54, 102, 73, 107, 101, 106, 82, 108, 77, 66, 109, 67, 102, 120, 118, 48, 84, 103, 56, 67, 116, 120, 112, 85, 82, 105, 103, 103]
Encrypt the Plaintext with AES_128_CBC_HMAC_SHA_256 using the CEK as the encryption key, the JWE Initialization Vector, and the Additional Authenticated Data value above. The steps for doing this using the values from Appendix A.3 are detailed in Appendix B. The resulting Ciphertext is:
[40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143, 112, 56, 102]
The resulting Authentication Tag value is:
[125, 141, 148, 252, 124, 121, 85, 199, 215, 154, 42, 68, 149, 209, 225, 48]
Base64url encode the Ciphertext to create the Encoded JWE Ciphertext. This result is:
KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY
Base64url encode the Authentication Tag to create the Encoded JWE Authentication Tag. This result is:
fY2U_Hx5VcfXmipEldHhMA
Assemble the final representation: The Compact Serialization of this result is the concatenation of the Encoded JWE Header, the Encoded JWE Encrypted Key, the Encoded JWE Initialization Vector, the Encoded JWE Ciphertext, and the Encoded JWE Authentication Tag in that order, with the five strings being separated by four period ('.') characters.
The final result in this example (with line breaks for display purposes only) is:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0. nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMkmOm kkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZjDYENR WiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfEJmNmfsx5f cB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWyEHW6WzQ4iH9S IcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_NSsx24LxtK6fIkej RlMBmCfxv0Tg8CtxpURigg. AxY8DCtDaGlsbGljb3RoZQ. KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY. fY2U_Hx5VcfXmipEldHhMA
This example illustrates the process of creating a JWE with RSAES-PKCS1-V1_5 and AES_CBC_HMAC_SHA2. These results can be used to validate JWE decryption implementations for these algorithms. Note that since the RSAES-PKCS1-V1_5 computation includes random values, the encryption results above will not be completely reproducible. However, since the AES CBC computation is deterministic, the JWE Encrypted Ciphertext values will be the same for all encryptions performed using these inputs.
This example encrypts the plaintext "Live long and prosper." to the recipient using AES Key Wrap and AES GCM. The representation of this plaintext is:
[76, 105, 118, 101, 32, 108, 111, 110, 103, 32, 97, 110, 100, 32, 112, 114, 111, 115, 112, 101, 114, 46]
The following example JWE Header declares that:
{"alg":"A128KW","enc":"A128CBC-HS256"}
Base64url encoding the octets of the UTF-8 representation of the JWE Header yields this Encoded JWE Header value:
eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0
Generate a 256 bit random Content Encryption Key (CEK). In this example, the value is:
[4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106, 206, 107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156, 44, 207]
Encrypt the CEK with the shared symmetric key using the AES Key Wrap algorithm to produce the JWE Encrypted Key. In this example, the shared symmetric key value is:
[25, 172, 32, 130, 225, 114, 26, 181, 138, 106, 254, 192, 95, 133, 74, 82]
The resulting JWE Encrypted Key value is:
[232, 160, 123, 211, 183, 76, 245, 132, 200, 128, 123, 75, 190, 216, 22, 67, 201, 138, 193, 186, 9, 91, 122, 31, 246, 90, 28, 139, 57, 3, 76, 124, 193, 11, 98, 37, 173, 61, 104, 57]
Base64url encode the JWE Encrypted Key to produce the Encoded JWE Encrypted Key. This result is:
6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ
Generate a random 128 bit JWE Initialization Vector. In this example, the value is:
[3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104, 101]
Base64url encoding this value yields the Encoded JWE Initialization Vector value:
AxY8DCtDaGlsbGljb3RoZQ
Concatenate the Encoded JWE Header value, a period ('.') character, and the Encoded JWE Encrypted Key to create the Additional Authenticated Data parameter. This result (with line breaks for display purposes only) is:
eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0. 6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ
The representation of this value is:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 66, 77, 84, 73, 52, 83, 49, 99, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73, 110, 48, 46, 54, 75, 66, 55, 48, 55, 100, 77, 57, 89, 84, 73, 103, 72, 116, 76, 118, 116, 103, 87, 81, 56, 109, 75, 119, 98, 111, 74, 87, 51, 111, 102, 57, 108, 111, 99, 105, 122, 107, 68, 84, 72, 122, 66, 67, 50, 73, 108, 114, 84, 49, 111, 79, 81]
Encrypt the Plaintext with AES_128_CBC_HMAC_SHA_256 using the CEK as the encryption key, the JWE Initialization Vector, and the Additional Authenticated Data value above. The steps for doing this using the values from this example are detailed in Appendix B. The resulting Ciphertext is:
[40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143, 112, 56, 102]
The resulting Authentication Tag value is:
[8, 65, 248, 101, 45, 185, 28, 218, 232, 112, 83, 79, 84, 221, 18, 172]
Base64url encode the Ciphertext to create the Encoded JWE Ciphertext. This result is:
KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY
Base64url encode the Authentication Tag to create the Encoded JWE Authentication Tag. This result is:
CEH4ZS25HNrocFNPVN0SrA
Assemble the final representation: The Compact Serialization of this result is the concatenation of the Encoded JWE Header, the Encoded JWE Encrypted Key, the Encoded JWE Initialization Vector, the Encoded JWE Ciphertext, and the Encoded JWE Authentication Tag in that order, with the five strings being separated by four period ('.') characters.
The final result in this example (with line breaks for display purposes only) is:
eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0. 6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ. AxY8DCtDaGlsbGljb3RoZQ. KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY. CEH4ZS25HNrocFNPVN0SrA
This example illustrates the process of creating a JWE with symmetric key wrap and AES_CBC_HMAC_SHA2. These results can be used to validate JWE decryption implementations for these algorithms. Also, since both the AES Key Wrap and AES GCM computations are deterministic, the resulting JWE value will be the same for all encryptions performed using these inputs. Since the computation is reproducible, these results can also be used to validate JWE encryption implementations for these algorithms.
This example shows the steps in the AES_128_CBC_HMAC_SHA_256 authenticated encryption computation using the values from the example in Appendix A.3. As described where this algorithm is defined in Sections 4.8 and 4.8.3 of JWA, the AES_CBC_HMAC_SHA2 family of algorithms are implemented using Advanced Encryption Standard (AES) in Cipher Block Chaining (CBC) mode with PKCS #5 padding to perform the encryption and an HMAC SHA-2 function to perform the integrity calculation - in this case, HMAC SHA-256.
The 256 bit AES_128_CBC_HMAC_SHA_256 key K used in this example is:
[4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106, 206, 107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156, 44, 207]
Use the first 128 bits of this key as the HMAC SHA-256 key MAC_KEY, which is:
[4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106, 206]
Use the last 128 bits of this key as the AES CBC key ENC_KEY, which is:
[107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156, 44, 207]
Note that the MAC key comes before the encryption key in the input key K; this is in the opposite order of the algorithm names in the identifiers "AES_128_CBC_HMAC_SHA_256" and A128CBC-HS256.
Encrypt the Plaintext with AES in Cipher Block Chaining (CBC) mode using PKCS #5 padding using the ENC_KEY above. The Plaintext in this example is:
[76, 105, 118, 101, 32, 108, 111, 110, 103, 32, 97, 110, 100, 32, 112, 114, 111, 115, 112, 101, 114, 46]
The encryption result is as follows, which is the Ciphertext output:
[40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143, 112, 56, 102]
The Additional Authenticated Data (AAD) in this example is:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 66, 77, 84, 73, 52, 83, 49, 99, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73, 110, 48, 46, 54, 75, 66, 55, 48, 55, 100, 77, 57, 89, 84, 73, 103, 72, 116, 76, 118, 116, 103, 87, 81, 56, 109, 75, 119, 98, 111, 74, 87, 51, 111, 102, 57, 108, 111, 99, 105, 122, 107, 68, 84, 72, 122, 66, 67, 50, 73, 108, 114, 84, 49, 111, 79, 81]
This AAD is 106 bytes long, which is 848 bits long. The octet string AL, which is the number of bits in AAD expressed as a big endian 64 bit unsigned integer is:
[0, 0, 0, 0, 0, 0, 3, 80]
The Initialization Vector value used in this example is:
[3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104, 101]
Concatenate the AAD, the Initialization Vector, the Ciphertext, and the AL value. The result of this concatenation is:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 66, 77, 84, 73, 52, 83, 49, 99, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73, 110, 48, 46, 54, 75, 66, 55, 48, 55, 100, 77, 57, 89, 84, 73, 103, 72, 116, 76, 118, 116, 103, 87, 81, 56, 109, 75, 119, 98, 111, 74, 87, 51, 111, 102, 57, 108, 111, 99, 105, 122, 107, 68, 84, 72, 122, 66, 67, 50, 73, 108, 114, 84, 49, 111, 79, 81, 3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104, 101, 40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143, 112, 56, 102, 0, 0, 0, 0, 0, 0, 3, 80]
Compute the HMAC SHA-256 of the concatenated value above. This result M is:
[8, 65, 248, 101, 45, 185, 28, 218, 232, 112, 83, 79, 84, 221, 18, 172, 50, 145, 207, 8, 14, 74, 44, 220, 100, 117, 32, 57, 239, 149, 173, 226]
Use the first half (128 bits) of the HMAC output M as the Authentication Tag output T. This truncated value is:
[8, 65, 248, 101, 45, 185, 28, 218, 232, 112, 83, 79, 84, 221, 18, 172]
The JWE encryption process in Section 5.1, and in particular in steps 15 and 16, hint at a possible compact serialization when there are multiple recipients. This possible compact serialization concatenates instances of the per-recipient fields, separating them with tilde ('~') characters, which are URL-safe.
The concatenation of the Encoded JWE Header values goes before the first period ('.') character in the compact serialization. The concatenation of the corresponding Encoded JWE Encoded Key values goes between the first and second period ('.') characters in the compact serialization.
A complete compact serialization of the multi-recipient JWE in Section 7.1 (with line breaks for display purposes only) would be:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0 ~ eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0 . nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMk mOmkkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZ jDYENRWiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfE JmNmfsx5fcB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWy EHW6WzQ4iH9SIcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_N Ssx24LxtK6fIkejRlMBmCfxv0Tg8CtxpURigg ~ 6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ . AxY8DCtDaGlsbGljb3RoZQ . KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY . LlhRZFfphc2f5X3nTTJP6g
Note that the octets of the UTF-8 representation of the first two parts of this serialization, including the period ('.') character separating them, are used as the AAD value in step 17 of the JWE encryption process in Section 5.1.
This representation is suggested for those who may desire or require a compact, URL-safe serialization of JWEs with multiple recipients. It is a suggestion to implementers for whom this functionality would be valuable, and not a normative part of this specification.
Solutions for encrypting JSON content were also explored by JSON Simple Encryption [JSE] and JavaScript Message Security Format [I-D.rescorla-jsms], both of which significantly influenced this draft. This draft attempts to explicitly reuse as many of the relevant concepts from XML Encryption 1.1 [W3C.CR-xmlenc-core1-20120313] and RFC 5652 [RFC5652] as possible, while utilizing simple compact JSON-based data structures.
Special thanks are due to John Bradley and Nat Sakimura for the discussions that helped inform the content of this specification and to Eric Rescorla and Joe Hildebrand for allowing the reuse of text from [I-D.rescorla-jsms] in this document.
Thanks to Axel Nennker, Emmanuel Raviart, Brian Campbell, and Edmund Jay for validating the examples in this specification.
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:
Richard Barnes, John Bradley, Brian Campbell, Breno de Medeiros, Dick Hardt, Jeff Hodges, Edmund Jay, James Manger, Tony Nadalin, Axel Nennker, Emmanuel Raviart, Nat Sakimura, Jim Schaad, 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.
[[ to be removed by the RFC editor before publication as an RFC ]]
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