< draft-ietf-jose-json-web-encryption-08.txt   draft-ietf-jose-json-web-encryption-09.txt >
JOSE Working Group M. Jones JOSE Working Group M. Jones
Internet-Draft Microsoft Internet-Draft Microsoft
Intended status: Standards Track E. Rescorla Intended status: Standards Track E. Rescorla
Expires: June 30, 2013 RTFM Expires: October 25, 2013 RTFM
J. Hildebrand J. Hildebrand
Cisco Cisco
December 27, 2012 April 23, 2013
JSON Web Encryption (JWE) JSON Web Encryption (JWE)
draft-ietf-jose-json-web-encryption-08 draft-ietf-jose-json-web-encryption-09
Abstract Abstract
JSON Web Encryption (JWE) is a means of representing encrypted JSON Web Encryption (JWE) is a means of representing encrypted
content using JavaScript Object Notation (JSON) data structures. content using JavaScript Object Notation (JSON) data structures.
Cryptographic algorithms and identifiers for use with this Cryptographic algorithms and identifiers for use with this
specification are described in the separate JSON Web Algorithms (JWA) specification are described in the separate JSON Web Algorithms (JWA)
specification. Related digital signature and MAC capabilities are specification. Related digital signature and MAC capabilities are
described in the separate JSON Web Signature (JWS) specification. described in the separate JSON Web Signature (JWS) specification.
skipping to change at page 1, line 38 skipping to change at page 1, line 38
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1. Notational Conventions . . . . . . . . . . . . . . . . . . 5 1.1. Notational Conventions . . . . . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. JSON Web Encryption (JWE) Overview . . . . . . . . . . . . . . 7 3. JSON Web Encryption (JWE) Overview . . . . . . . . . . . . . . 8
3.1. Example JWE using RSAES OAEP and AES GCM . . . . . . . . . 8 3.1. Example JWE using RSAES OAEP and AES GCM . . . . . . . . . 8
3.2. Example JWE using RSAES-PKCS1-V1_5 and AES CBC . . . . . . 9 3.2. Example JWE using RSAES-PKCS1-V1_5 and
AES_128_CBC_HMAC_SHA_256 . . . . . . . . . . . . . . . . . 10
4. JWE Header . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4. JWE Header . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1. Reserved Header Parameter Names . . . . . . . . . . . . . 12 4.1. Reserved Header Parameter Names . . . . . . . . . . . . . 12
4.1.1. "alg" (Algorithm) Header Parameter . . . . . . . . . . 12 4.1.1. "alg" (Algorithm) Header Parameter . . . . . . . . . . 12
4.1.2. "enc" (Encryption Method) Header Parameter . . . . . . 12 4.1.2. "enc" (Encryption Method) Header Parameter . . . . . . 12
4.1.3. "epk" (Ephemeral Public Key) Header Parameter . . . . 13 4.1.3. "epk" (Ephemeral Public Key) Header Parameter . . . . 13
4.1.4. "zip" (Compression Algorithm) Header Parameter . . . . 13 4.1.4. "zip" (Compression Algorithm) Header Parameter . . . . 13
4.1.5. "jku" (JWK Set URL) Header Parameter . . . . . . . . . 13 4.1.5. "jku" (JWK Set URL) Header Parameter . . . . . . . . . 13
4.1.6. "jwk" (JSON Web Key) Header Parameter . . . . . . . . 13 4.1.6. "jwk" (JSON Web Key) Header Parameter . . . . . . . . 13
4.1.7. "x5u" (X.509 URL) Header Parameter . . . . . . . . . . 13 4.1.7. "x5u" (X.509 URL) Header Parameter . . . . . . . . . . 13
4.1.8. "x5t" (X.509 Certificate Thumbprint) Header 4.1.8. "x5t" (X.509 Certificate Thumbprint) Header
Parameter . . . . . . . . . . . . . . . . . . . . . . 14 Parameter . . . . . . . . . . . . . . . . . . . . . . 14
4.1.9. "x5c" (X.509 Certificate Chain) Header Parameter . . . 14 4.1.9. "x5c" (X.509 Certificate Chain) Header Parameter . . . 14
4.1.10. "kid" (Key ID) Header Parameter . . . . . . . . . . . 15 4.1.10. "kid" (Key ID) Header Parameter . . . . . . . . . . . 15
4.1.11. "typ" (Type) Header Parameter . . . . . . . . . . . . 15 4.1.11. "typ" (Type) Header Parameter . . . . . . . . . . . . 15
4.1.12. "cty" (Content Type) Header Parameter . . . . . . . . 15 4.1.12. "cty" (Content Type) Header Parameter . . . . . . . . 15
4.1.13. "apu" (Agreement PartyUInfo) Header Parameter . . . . 15 4.1.13. "apu" (Agreement PartyUInfo) Header Parameter . . . . 15
4.1.14. "apv" (Agreement PartyVInfo) Header Parameter . . . . 15 4.1.14. "apv" (Agreement PartyVInfo) Header Parameter . . . . 16
4.1.15. "epu" (Encryption PartyUInfo) Header Parameter . . . . 16 4.1.15. "crit" (Critical) Header Parameter . . . . . . . . . . 16
4.1.16. "epv" (Encryption PartyVInfo) Header Parameter . . . . 16
4.2. Public Header Parameter Names . . . . . . . . . . . . . . 16 4.2. Public Header Parameter Names . . . . . . . . . . . . . . 16
4.3. Private Header Parameter Names . . . . . . . . . . . . . . 16 4.3. Private Header Parameter Names . . . . . . . . . . . . . . 16
5. Producing and Consuming JWEs . . . . . . . . . . . . . . . . . 16 5. Producing and Consuming JWEs . . . . . . . . . . . . . . . . . 17
5.1. Message Encryption . . . . . . . . . . . . . . . . . . . . 16 5.1. Message Encryption . . . . . . . . . . . . . . . . . . . . 17
5.2. Message Decryption . . . . . . . . . . . . . . . . . . . . 18 5.2. Message Decryption . . . . . . . . . . . . . . . . . . . . 19
5.3. String Comparison Rules . . . . . . . . . . . . . . . . . 19 5.3. String Comparison Rules . . . . . . . . . . . . . . . . . 20
6. Encrypting JWEs with Cryptographic Algorithms . . . . . . . . 20 6. Encrypting JWEs with Cryptographic Algorithms . . . . . . . . 21
6.1. CMK Encryption . . . . . . . . . . . . . . . . . . . . . . 20 6.1. CEK Encryption . . . . . . . . . . . . . . . . . . . . . . 21
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 7. JSON Serialization . . . . . . . . . . . . . . . . . . . . . . 21
7.1. Registration of JWE Header Parameter Names . . . . . . . . 20 7.1. Example JWE-JS . . . . . . . . . . . . . . . . . . . . . . 23
7.1.1. Registry Contents . . . . . . . . . . . . . . . . . . 21 8. Implementation Considerations . . . . . . . . . . . . . . . . 24
7.2. JSON Web Signature and Encryption Type Values 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24
Registration . . . . . . . . . . . . . . . . . . . . . . . 22 9.1. Registration of JWE Header Parameter Names . . . . . . . . 24
7.2.1. Registry Contents . . . . . . . . . . . . . . . . . . 22 9.1.1. Registry Contents . . . . . . . . . . . . . . . . . . 24
7.3. Media Type Registration . . . . . . . . . . . . . . . . . 23 9.2. JSON Web Signature and Encryption Type Values
7.3.1. Registry Contents . . . . . . . . . . . . . . . . . . 23 Registration . . . . . . . . . . . . . . . . . . . . . . . 26
8. Security Considerations . . . . . . . . . . . . . . . . . . . 23 9.2.1. Registry Contents . . . . . . . . . . . . . . . . . . 26
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 24 9.3. Media Type Registration . . . . . . . . . . . . . . . . . 26
9.1. Normative References . . . . . . . . . . . . . . . . . . . 24 9.3.1. Registry Contents . . . . . . . . . . . . . . . . . . 26
9.2. Informative References . . . . . . . . . . . . . . . . . . 25 10. Security Considerations . . . . . . . . . . . . . . . . . . . 28
Appendix A. JWE Examples . . . . . . . . . . . . . . . . . . . . 25 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28
A.1. Example JWE using RSAES OAEP and AES GCM . . . . . . . . . 26 11.1. Normative References . . . . . . . . . . . . . . . . . . . 28
A.1.1. JWE Header . . . . . . . . . . . . . . . . . . . . . . 26 11.2. Informative References . . . . . . . . . . . . . . . . . . 30
A.1.2. Encoded JWE Header . . . . . . . . . . . . . . . . . . 26 Appendix A. JWE Examples . . . . . . . . . . . . . . . . . . . . 30
A.1.3. Content Master Key (CMK) . . . . . . . . . . . . . . . 26 A.1. Example JWE using RSAES OAEP and AES GCM . . . . . . . . . 31
A.1.4. Key Encryption . . . . . . . . . . . . . . . . . . . . 26 A.1.1. JWE Header . . . . . . . . . . . . . . . . . . . . . . 31
A.1.5. Encoded JWE Encrypted Key . . . . . . . . . . . . . . 29 A.1.2. Encoded JWE Header . . . . . . . . . . . . . . . . . . 31
A.1.6. Initialization Vector . . . . . . . . . . . . . . . . 29 A.1.3. Content Encryption Key (CEK) . . . . . . . . . . . . . 31
A.1.7. "Additional Authenticated Data" Parameter . . . . . . 29 A.1.4. Key Encryption . . . . . . . . . . . . . . . . . . . . 31
A.1.8. Plaintext Encryption . . . . . . . . . . . . . . . . . 30 A.1.5. Encoded JWE Encrypted Key . . . . . . . . . . . . . . 34
A.1.9. Encoded JWE Ciphertext . . . . . . . . . . . . . . . . 30 A.1.6. Initialization Vector . . . . . . . . . . . . . . . . 34
A.1.10. Encoded JWE Integrity Value . . . . . . . . . . . . . 31 A.1.7. Additional Authenticated Data Parameter . . . . . . . 34
A.1.11. Complete Representation . . . . . . . . . . . . . . . 31 A.1.8. Plaintext Encryption . . . . . . . . . . . . . . . . . 35
A.1.12. Validation . . . . . . . . . . . . . . . . . . . . . . 31 A.1.9. Encoded JWE Ciphertext . . . . . . . . . . . . . . . . 35
A.2. Example JWE using RSAES-PKCS1-V1_5 and AES CBC . . . . . . 31 A.1.10. Encoded JWE Authentication Tag . . . . . . . . . . . . 36
A.2.1. JWE Header . . . . . . . . . . . . . . . . . . . . . . 32 A.1.11. Complete Representation . . . . . . . . . . . . . . . 36
A.2.2. Encoded JWE Header . . . . . . . . . . . . . . . . . . 32 A.1.12. Validation . . . . . . . . . . . . . . . . . . . . . . 36
A.2.3. Content Master Key (CMK) . . . . . . . . . . . . . . . 32 A.2. Example JWE using RSAES-PKCS1-V1_5 and
A.2.4. Key Encryption . . . . . . . . . . . . . . . . . . . . 32 AES_128_CBC_HMAC_SHA_256 . . . . . . . . . . . . . . . . . 36
A.2.5. Encoded JWE Encrypted Key . . . . . . . . . . . . . . 35 A.2.1. JWE Header . . . . . . . . . . . . . . . . . . . . . . 37
A.2.6. Key Derivation . . . . . . . . . . . . . . . . . . . . 35 A.2.2. Encoded JWE Header . . . . . . . . . . . . . . . . . . 37
A.2.7. Initialization Vector . . . . . . . . . . . . . . . . 35 A.2.3. Content Encryption Key (CEK) . . . . . . . . . . . . . 37
A.2.8. Plaintext Encryption . . . . . . . . . . . . . . . . . 35 A.2.4. Key Encryption . . . . . . . . . . . . . . . . . . . . 37
A.2.9. Encoded JWE Ciphertext . . . . . . . . . . . . . . . . 36 A.2.5. Encoded JWE Encrypted Key . . . . . . . . . . . . . . 40
A.2.10. Secured Input Value . . . . . . . . . . . . . . . . . 36 A.2.6. Initialization Vector . . . . . . . . . . . . . . . . 40
A.2.11. JWE Integrity Value . . . . . . . . . . . . . . . . . 37 A.2.7. Additional Authenticated Data Parameter . . . . . . . 40
A.2.12. Encoded JWE Integrity Value . . . . . . . . . . . . . 37 A.2.8. Plaintext Encryption . . . . . . . . . . . . . . . . . 41
A.2.13. Complete Representation . . . . . . . . . . . . . . . 37 A.2.9. Encoded JWE Ciphertext . . . . . . . . . . . . . . . . 41
A.2.14. Validation . . . . . . . . . . . . . . . . . . . . . . 38 A.2.10. Encoded JWE Authentication Tag . . . . . . . . . . . . 42
A.3. Example JWE using AES Key Wrap and AES GCM . . . . . . . . 38 A.2.11. Complete Representation . . . . . . . . . . . . . . . 42
A.3.1. JWE Header . . . . . . . . . . . . . . . . . . . . . . 38 A.2.12. Validation . . . . . . . . . . . . . . . . . . . . . . 42
A.3.2. Encoded JWE Header . . . . . . . . . . . . . . . . . . 39 A.3. Example JWE using AES Key Wrap and AES GCM . . . . . . . . 42
A.3.3. Content Master Key (CMK) . . . . . . . . . . . . . . . 39 A.3.1. JWE Header . . . . . . . . . . . . . . . . . . . . . . 43
A.3.4. Key Encryption . . . . . . . . . . . . . . . . . . . . 39 A.3.2. Encoded JWE Header . . . . . . . . . . . . . . . . . . 43
A.3.5. Encoded JWE Encrypted Key . . . . . . . . . . . . . . 39 A.3.3. Content Encryption Key (CEK) . . . . . . . . . . . . . 43
A.3.6. Initialization Vector . . . . . . . . . . . . . . . . 39 A.3.4. Key Encryption . . . . . . . . . . . . . . . . . . . . 43
A.3.7. "Additional Authenticated Data" Parameter . . . . . . 40 A.3.5. Encoded JWE Encrypted Key . . . . . . . . . . . . . . 44
A.3.8. Plaintext Encryption . . . . . . . . . . . . . . . . . 40 A.3.6. Initialization Vector . . . . . . . . . . . . . . . . 44
A.3.9. Encoded JWE Ciphertext . . . . . . . . . . . . . . . . 40 A.3.7. Additional Authenticated Data Parameter . . . . . . . 44
A.3.10. Encoded JWE Integrity Value . . . . . . . . . . . . . 41 A.3.8. Plaintext Encryption . . . . . . . . . . . . . . . . . 44
A.3.11. Complete Representation . . . . . . . . . . . . . . . 41 A.3.9. Encoded JWE Ciphertext . . . . . . . . . . . . . . . . 45
A.3.12. Validation . . . . . . . . . . . . . . . . . . . . . . 41 A.3.10. Encoded JWE Authentication Tag . . . . . . . . . . . . 45
A.4. Example Key Derivation for "enc" value "A128CBC+HS256" . . 41 A.3.11. Complete Representation . . . . . . . . . . . . . . . 45
A.4.1. CEK Generation . . . . . . . . . . . . . . . . . . . . 42 A.3.12. Validation . . . . . . . . . . . . . . . . . . . . . . 45
A.4.2. CIK Generation . . . . . . . . . . . . . . . . . . . . 43 Appendix B. Example AES_128_CBC_HMAC_SHA_256 Computation . . . . 46
A.5. Example Key Derivation for "enc" value "A256CBC+HS512" . . 44 B.1. Extract MAC_KEY and ENC_KEY from Key . . . . . . . . . . . 46
A.5.1. CEK Generation . . . . . . . . . . . . . . . . . . . . 44 B.2. Encrypt Plaintext to Create Ciphertext . . . . . . . . . . 46
A.5.2. CIK Generation . . . . . . . . . . . . . . . . . . . . 45 B.3. Create 64 Bit Big Endian Representation of AAD Length . . 47
Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 46 B.4. Initialization Vector Value . . . . . . . . . . . . . . . 47
Appendix C. Open Issues . . . . . . . . . . . . . . . . . . . . . 47 B.5. Create Input to HMAC Computation . . . . . . . . . . . . . 47
Appendix D. Document History . . . . . . . . . . . . . . . . . . 47 B.6. Compute HMAC Value . . . . . . . . . . . . . . . . . . . . 48
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 51 B.7. Truncate HMAC Value to Create Authentication Tag . . . . . 48
Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 48
Appendix D. Document History . . . . . . . . . . . . . . . . . . 49
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 54
1. Introduction 1. Introduction
JSON Web Encryption (JWE) is a compact encryption format intended for JSON Web Encryption (JWE) is a compact encryption format intended for
space constrained environments such as HTTP Authorization headers and space constrained environments such as HTTP Authorization headers and
URI query parameters. It represents this content using JavaScript URI query parameters. It represents this content using JavaScript
Object Notation (JSON) [RFC4627] based data structures. The JWE Object Notation (JSON) [RFC4627] based data structures. The JWE
cryptographic mechanisms encrypt and provide integrity protection for cryptographic mechanisms encrypt and provide integrity protection for
arbitrary sequences of bytes. arbitrary sequences of octets.
Cryptographic algorithms and identifiers for use with this Cryptographic algorithms and identifiers for use with this
specification are described in the separate JSON Web Algorithms (JWA) specification are described in the separate JSON Web Algorithms (JWA)
[JWA] specification. Related digital signature and MAC capabilities [JWA] specification. Related digital signature and MAC capabilities
are described in the separate JSON Web Signature (JWS) [JWS] are described in the separate JSON Web Signature (JWS) [JWS]
specification. specification.
1.1. Notational Conventions 1.1. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in Key words for use in document are to be interpreted as described in Key words for use in
RFCs to Indicate Requirement Levels [RFC2119]. RFCs to Indicate Requirement Levels [RFC2119].
2. Terminology 2. Terminology
JSON Web Encryption (JWE) A data structure representing an encrypted JSON Web Encryption (JWE) A data structure representing an encrypted
message. The structure consists of five parts: the JWE Header, message. The structure represents five values: the JWE Header,
the JWE Encrypted Key, the JWE Initialization Vector, the JWE the JWE Encrypted Key, the JWE Initialization Vector, the JWE
Ciphertext, and the JWE Integrity Value. Ciphertext, and the JWE Authentication Tag.
Plaintext The bytes to be encrypted -- a.k.a., the message. The Authenticated Encryption An Authenticated Encryption algorithm is
plaintext can contain an arbitrary sequence of bytes. one that provides an integrated content integrity check.
Authenticated Encryption algorithms accept two inputs, the
Plaintext and the Additional Authenticated Data value, and produce
two outputs, the Ciphertext and the Authentication Tag value. AES
Galois/Counter Mode (GCM) is one such algorithm.
Plaintext The sequence of octets to be encrypted -- a.k.a., the
message. The plaintext can contain an arbitrary sequence of
octets.
Ciphertext An encrypted representation of the Plaintext. Ciphertext An encrypted representation of the Plaintext.
Content Encryption Key (CEK) A symmetric key used to encrypt the Additional Associated Data (AAD) An input to an Authenticated
Plaintext for the recipient to produce the Ciphertext. Encryption operation that is integrity protected but not
encrypted.
Content Integrity Key (CIK) A key used with a MAC function to ensure Authentication Tag An output of an Authenticated Encryption
the integrity of the Ciphertext and the parameters used to create operation that ensures the integrity of the Ciphertext and the
it. Additional Associated Data.
Content Master Key (CMK) A key from which the CEK and CIK are Content Encryption Key (CEK) A symmetric key for the Authenticated
derived. When key wrapping or key encryption are employed, the Encryption algorithm used to encrypt the Plaintext for the
CMK is randomly generated and encrypted to the recipient as the recipient to produce the Ciphertext and the Authentication Tag.
JWE Encrypted Key. When direct encryption with a shared symmetric
key is employed, the CMK is the shared key. When key agreement
without key wrapping is employed, the CMK is the result of the key
agreement algorithm.
JSON Text Object A UTF-8 encoded text string representing a JSON JSON Text Object A UTF-8 [RFC3629] encoded text string representing
object; the syntax of JSON objects is defined in Section 2.2 of a JSON object; the syntax of JSON objects is defined in Section
[RFC4627]. 2.2 of [RFC4627].
JWE Header A JSON Text Object that describes the encryption JWE Header A JSON Text Object that describes the encryption
operations applied to create the JWE Encrypted Key, the JWE operations applied to create the JWE Encrypted Key, the JWE
Ciphertext, and the JWE Integrity Value. Ciphertext, and the JWE Authentication Tag.
JWE Encrypted Key When key wrapping or key encryption are employed, JWE Encrypted Key The result of encrypting the Content Encryption
the Content Master Key (CMK) is encrypted with the intended Key (CEK) with the intended recipient's key using the specified
recipient's key and the resulting encrypted content is recorded as algorithm. Note that for some algorithms, the JWE Encrypted Key
a byte array, which is referred to as the JWE Encrypted Key. value is specified as being the empty octet sequence.
Otherwise, when direct encryption with a shared or agreed upon
symmetric key is employed, the JWE Encrypted Key is the empty byte
array.
JWE Initialization Vector A byte array containing the Initialization JWE Initialization Vector A sequence of octets containing the
Vector used when encrypting the Plaintext. Initialization Vector used when encrypting the Plaintext. Note
that some algorithms may not use an Initialization Vector, in
which case this value is the empty octet sequence.
JWE Ciphertext A byte array containing the Ciphertext. JWE Ciphertext A sequence of octets containing the Ciphertext for a
JWE.
JWE Integrity Value A byte array containing a MAC value that ensures JWE Authentication Tag A sequence of octets containing the
the integrity of the Ciphertext and the parameters used to create Authentication Tag for a JWE.
it.
Base64url Encoding The URL- and filename-safe Base64 encoding Base64url Encoding The URL- and filename-safe Base64 encoding
described in RFC 4648 [RFC4648], Section 5, with the (non URL- described in RFC 4648 [RFC4648], Section 5, with the (non URL-
safe) '=' padding characters omitted, as permitted by Section 3.2. safe) '=' padding characters omitted, as permitted by Section 3.2.
(See Appendix C of [JWS] for notes on implementing base64url (See Appendix C of [JWS] for notes on implementing base64url
encoding without padding.) encoding without padding.)
Encoded JWE Header Base64url encoding of the JWE Header. Encoded JWE Header Base64url encoding of the JWE Header.
Encoded JWE Encrypted Key Base64url encoding of the JWE Encrypted Encoded JWE Encrypted Key Base64url encoding of the JWE Encrypted
Key. Key.
Encoded JWE Initialization Vector Base64url encoding of the JWE Encoded JWE Initialization Vector Base64url encoding of the JWE
Initialization Vector. Initialization Vector.
Encoded JWE Ciphertext Base64url encoding of the JWE Ciphertext. Encoded JWE Ciphertext Base64url encoding of the JWE Ciphertext.
Encoded JWE Integrity Value Base64url encoding of the JWE Integrity Encoded JWE Authentication Tag Base64url encoding of the JWE
Value. Authentication Tag.
Header Parameter Name The name of a member of the JWE Header. Header Parameter Name The name of a member of the JWE Header.
Header Parameter Value The value of a member of the JWE Header. Header Parameter Value The value of a member of the JWE Header.
JWE Compact Serialization A representation of the JWE as the JWE Compact Serialization A representation of the JWE as the
concatenation of the Encoded JWE Header, the Encoded JWE Encrypted concatenation of the Encoded JWE Header, the Encoded JWE Encrypted
Key, the Encoded JWE Initialization Vector, the Encoded JWE Key, the Encoded JWE Initialization Vector, the Encoded JWE
Ciphertext, and the Encoded JWE Integrity Value in that order, Ciphertext, and the Encoded JWE Authentication Tag in that order,
with the five strings being separated by four period ('.') with the five strings being separated by four period ('.')
characters. characters. This results in a compact, URL-safe representation.
Authenticated Encryption An Authenticated Encryption algorithm is JWE JSON Serialization A representation of the JWE as a JSON
one that provides an integrated content integrity check. structure containing Encoded JWE Header, Encoded JWE Encrypted
Authenticated Encryption algorithms accept two inputs, the Key, Encoded JWE Initialization Vector, Encoded JWE Ciphertext,
plaintext and the "additional authenticated data" value, and and Encoded JWE Authentication Tag values. Unlike the JWE Compact
produce two outputs, the ciphertext and the "authentication tag" Serialization, the JWE JSON Serialization enables the same content
value. AES Galois/Counter Mode (GCM) is one such algorithm. to be encrypted to multiple parties. This representation is
neither compact nor URL-safe.
Collision Resistant Namespace A namespace that allows names to be Collision Resistant Namespace A namespace that allows names to be
allocated in a manner such that they are highly unlikely to allocated in a manner such that they are highly unlikely to
collide with other names. For instance, collision resistance can collide with other names. For instance, collision resistance can
be achieved through administrative delegation of portions of the be achieved through administrative delegation of portions of the
namespace or through use of collision-resistant name allocation namespace or through use of collision-resistant name allocation
functions. Examples of Collision Resistant Namespaces include: functions. Examples of Collision Resistant Namespaces include:
Domain Names, Object Identifiers (OIDs) as defined in the ITU-T Domain Names, Object Identifiers (OIDs) as defined in the ITU-T
X.660 and X.670 Recommendation series, and Universally Unique X.660 and X.670 Recommendation series, and Universally Unique
IDentifiers (UUIDs) [RFC4122]. When using an administratively IDentifiers (UUIDs) [RFC4122]. When using an administratively
delegated namespace, the definer of a name needs to take delegated namespace, the definer of a name needs to take
reasonable precautions to ensure they are in control of the reasonable precautions to ensure they are in control of the
portion of the namespace they use to define the name. portion of the namespace they use to define the name.
StringOrURI A JSON string value, with the additional requirement StringOrURI A JSON string value, with the additional requirement
that while arbitrary string values MAY be used, any value that while arbitrary string values MAY be used, any value
containing a ":" character MUST be a URI [RFC3986]. StringOrURI containing a ":" character MUST be a URI [RFC3986]. StringOrURI
values are compared as case-sensitive strings with no values are compared as case-sensitive strings with no
transformations or canonicalizations applied. transformations or canonicalizations applied.
Key Management Mode A method of determining the Content Encryption
Key (CEK) value to use. Each algorithm used for determining the
CEK value uses a specific Key Management Mode. Key Management
Modes employed by this specification are Key Encryption, Key
Wrapping, Direct Key Agreement, Key Agreement with Key Wrapping,
and Direct Encryption.
Key Encryption A Key Management Mode in which the Content Encryption
Key (CEK) value is encrypted to the intended recipient using an
asymmetric encryption algorithm.
Key Wrapping A Key Management Mode in which the Content Encryption
Key (CEK) value is encrypted to the intended recipient using a
symmetric key wrapping algorithm.
Direct Key Agreement A Key Management Mode in which a key agreement
algorithm is used to agree upon the Content Encryption Key (CEK)
value.
Key Agreement with Key Wrapping A Key Management Mode in which a key
agreement algorithm is used to agree upon a symmetric key used to
encrypt the Content Encryption Key (CEK) value to the intended
recipient using a symmetric key wrapping algorithm.
Direct Encryption A Key Management Mode in which the Content
Encryption Key (CEK) value used is the secret symmetric key value
shared between the parties.
3. JSON Web Encryption (JWE) Overview 3. JSON Web Encryption (JWE) Overview
JWE represents encrypted content using JSON data structures and JWE represents encrypted content using JSON data structures and
base64url encoding. The representation consists of five parts: the base64url encoding. Five values are represented in a JWE: the JWE
JWE Header, the JWE Encrypted Key, the JWE Initialization Vector, the Header, the JWE Encrypted Key, the JWE Initialization Vector, the JWE
JWE Ciphertext, and the JWE Integrity Value. In the Compact Ciphertext, and the JWE Authentication Tag. In the Compact
Serialization, the five parts are base64url-encoded for transmission, Serialization, the five values are base64url-encoded for
and represented as the concatenation of the encoded strings in that transmission, and represented as the concatenation of the encoded
order, with the five strings being separated by four period ('.') strings in that order, with the five strings being separated by four
characters. (A JSON Serialization for this information is defined in period ('.') characters. A JSON Serialization for this information
the separate JSON Web Encryption JSON Serialization (JWE-JS) [JWE-JS] is also defined in Section 7.
specification.)
JWE utilizes encryption to ensure the confidentiality of the JWE utilizes authenticated encryption to ensure the confidentiality
Plaintext. JWE adds a content integrity check if not provided by the and integrity of the Plaintext.
underlying encryption algorithm.
3.1. Example JWE using RSAES OAEP and AES GCM 3.1. Example JWE using RSAES OAEP and AES GCM
This example encrypts the plaintext "Live long and prosper." to the This example encrypts the plaintext "The true sign of intelligence is
recipient using RSAES OAEP and AES GCM. The AES GCM algorithm has an not knowledge but imagination." to the recipient using RSAES OAEP and
integrated integrity check. AES GCM.
The following example JWE Header declares that: The following example JWE Header declares that:
o the Content Master Key is encrypted to the recipient using the o the Content Encryption Key is encrypted to the recipient using the
RSAES OAEP algorithm to produce the JWE Encrypted Key and RSAES OAEP algorithm to produce the JWE Encrypted Key and
o the Plaintext is encrypted using the AES GCM algorithm with a 256 o the Plaintext is encrypted using the AES GCM algorithm with a 256
bit key to produce the Ciphertext. bit key to produce the Ciphertext.
{"alg":"RSA-OAEP","enc":"A256GCM"} {"alg":"RSA-OAEP","enc":"A256GCM"}
Base64url encoding the bytes of the UTF-8 representation of the JWE Base64url encoding the octets of the UTF-8 representation of the JWE
Header yields this Encoded JWE Header value: Header yields this Encoded JWE Header value:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ
The remaining steps to finish creating this JWE are: The remaining steps to finish creating this JWE are:
o Generate a random Content Master Key (CMK) o Generate a random Content Encryption Key (CEK)
o Encrypt the CMK with the recipient's public key using the RSAES o Encrypt the CEK with the recipient's public key using the RSAES
OAEP algorithm to produce the JWE Encrypted Key OAEP algorithm to produce the JWE Encrypted Key
o Base64url encode the JWE Encrypted Key to produce the Encoded JWE o Base64url encode the JWE Encrypted Key to produce the Encoded JWE
Encrypted Key Encrypted Key
o Generate a random JWE Initialization Vector o Generate a random JWE Initialization Vector
o Base64url encode the JWE Initialization Vector to produce the o Base64url encode the JWE Initialization Vector to produce the
Encoded JWE Initialization Vector Encoded JWE Initialization Vector
o Concatenate the Encoded JWE Header value, a period character o Concatenate the Encoded JWE Header value, a period ('.')
('.'), the Encoded JWE Encrypted Key, a second period character character, and the Encoded JWE Encrypted Key to create the
('.'), and the Encoded JWE Initialization Vector to create the Additional Authenticated Data parameter
"additional authenticated data" parameter for the AES GCM
algorithm
o Encrypt the Plaintext with AES GCM, using the CMK as the o Encrypt the Plaintext with AES GCM using the CEK as the encryption
encryption key, the JWE Initialization Vector, and the "additional key, the JWE Initialization Vector, and the Additional
authenticated data" value above, requesting a 128 bit Authenticated Data value, requesting a 128 bit Authentication Tag
"authentication tag" output output
o Base64url encode the resulting Ciphertext to create the Encoded o Base64url encode the Ciphertext to create the Encoded JWE
JWE Ciphertext Ciphertext
o Base64url encode the resulting "authentication tag" to create the o Base64url encode the Authentication Tag to create the Encoded JWE
Encoded JWE Integrity Value Authentication Tag
o Assemble the final representation: The Compact Serialization of o Assemble the final representation: The Compact Serialization of
this result is the concatenation of the Encoded JWE Header, the this result is the concatenation of the Encoded JWE Header, the
Encoded JWE Encrypted Key, the Encoded JWE Initialization Vector, Encoded JWE Encrypted Key, the Encoded JWE Initialization Vector,
the Encoded JWE Ciphertext, and the Encoded JWE Integrity Value in the Encoded JWE Ciphertext, and the Encoded JWE Authentication Tag
that order, with the five strings being separated by four period in that order, with the five strings being separated by four
('.') characters. period ('.') characters.
The final result in this example (with line breaks for display The final result in this example (with line breaks for display
purposes only) is: purposes only) is:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ. eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ.
M2XxpbORKezKSzzQL_95-GjiudRBTqn_omS8z9xgoRb7L0Jw5UsEbxmtyHn2T71m ApfOLCaDbqs_JXPYy2I937v_xmrzj-Iss1mG6NAHmeJViM6j2l0MHvfseIdHVyU2
rZLkjg4Mp8gbhYoltPkEOHvAopz25-vZ8C2e1cOaAo5WPcbSIuFcB4DjBOM3t0UA BIoGVu9ohvkkWiRq5DL2jYZTPA9TAdwq3FUIVyoH-Pedf6elHIVFi2KGDEspYMtQ
O6JHkWLuAEYoe58lcxIQneyKdaYSLbV9cKqoUoFQpvKWYRHZbfszIyfsa18rmgTj ARMMSBcS7pslx6flh1Cfh3GBKysztVMEhZ_maFkm4PYVCsJsvq6Ct3fg2CJPOs0X
zrtLDTPnc09DSJE24aQ8w3i8RXEDthW9T1J6LsTH_vwHdwUgkI-tC2PNeGrnM-dN 1DHuxZKoIGIqcbeK4XEO5a0h5TAuJObKdfO0dKwfNSSbpu5sFrpRFwV2FTTYoqF4
SfzF3Y7-lwcGy0FsdXkPXytvDV7y4pZeeUiQ-0VdibIN2AjjfW60nfrPuOjepMFG zI46N9-_hMIznlEpftRXhScEJuZ9HG8C8CHB1WRZ_J48PleqdhF4o7fB5J1wFqUX
6BBBbR37pHcyzext9epOAQ. BtbtuGJ_A2Xe6AEhrlzCOw.
48V1_ALb6US04U3b. 48V1_ALb6US04U3b.
_e21tGGhac_peEFkLXr2dMPUZiUkrw. 5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji
7V5ZDko0v_mf2PAc4JMiUg SdiwkIr3ajwQzaBtQD_A.
ghEgxninkHEAMp4xZtB2mA
See Appendix A.1 for the complete details of computing this JWE. See Appendix A.1 for the complete details of computing this JWE.
3.2. Example JWE using RSAES-PKCS1-V1_5 and AES CBC 3.2. Example JWE using RSAES-PKCS1-V1_5 and AES_128_CBC_HMAC_SHA_256
This example encrypts the plaintext "No matter where you go, there This example encrypts the plaintext "Live long and prosper." to the
you are." to the recipient using RSAES-PKCS1-V1_5 and AES CBC. AES recipient using RSAES-PKCS1-V1_5 and AES_128_CBC_HMAC_SHA_256.
CBC does not have an integrated integrity check, so a separate
integrity check calculation is performed using HMAC SHA-256, with
separate encryption and integrity keys being derived from a master
key using the Concat KDF with the SHA-256 digest function.
The following example JWE Header (with line breaks for display The following example JWE Header (with line breaks for display
purposes only) declares that: purposes only) declares that:
o the Content Master Key is encrypted to the recipient using the o the Content Encryption Key is encrypted to the recipient using the
RSAES-PKCS1-V1_5 algorithm to produce the JWE Encrypted Key and RSAES-PKCS1-V1_5 algorithm to produce the JWE Encrypted Key and
o the Plaintext is encrypted using the AES CBC algorithm with a 128 o the Plaintext is encrypted using the AES_128_CBC_HMAC_SHA_256
bit key to produce the Ciphertext, with the integrity of the algorithm to produce the Ciphertext.
Ciphertext and the parameters used to create it being secured
using the HMAC SHA-256 algorithm.
{"alg":"RSA1_5","enc":"A128CBC+HS256"} {"alg":"RSA1_5","enc":"A128CBC-HS256"}
Base64url encoding the bytes of the UTF-8 representation of the JWE Base64url encoding the octets of the UTF-8 representation of the JWE
Header yields this Encoded JWE Header value: Header yields this Encoded JWE Header value:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDK0hTMjU2In0 eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDK0hTMjU2In0
The remaining steps to finish creating this JWE are like the previous The remaining steps to finish creating this JWE are the same as for
example, but with an additional step to compute the separate the previous example, but using RSAES-PKCS1-v1_5 instead of RSAES
integrity value: 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.
o Generate a random Content Master Key (CMK)
o Encrypt the CMK with the recipient's public key using the RSAES-
PKCS1-V1_5 algorithm to produce the JWE Encrypted Key
o Base64url encode the JWE Encrypted Key to produce the Encoded JWE
Encrypted Key
o Generate a random JWE Initialization Vector
o Base64url encode the JWE Initialization Vector to produce the
Encoded JWE Initialization Vector
o Use the Concat key derivation function to derive Content
Encryption Key (CEK) and Content Integrity Key (CIK) values from
the CMK
o Encrypt the Plaintext with AES CBC using the CEK and JWE
Initialization Vector to produce the Ciphertext
o Base64url encode the resulting Ciphertext to create the Encoded
JWE Ciphertext
o Concatenate the Encoded JWE Header value, a period character
('.'), the Encoded JWE Encrypted Key, a second period character
('.'), the Encoded JWE Initialization Vector, a third period ('.')
character, and the Encoded JWE Ciphertext to create the value to
integrity protect
o Compute the HMAC SHA-256 of this value using the CIK to create the
JWE Integrity Value
o Base64url encode the resulting JWE Integrity Value to create the
Encoded JWE Integrity Value
o 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 Integrity Value in
that order, with the five strings being separated by four period
('.') characters.
The final result in this example (with line breaks for display The final result in this example (with line breaks for display
purposes only) is: purposes only) is:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDK0hTMjU2In0. eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.
O6AqXqgVlJJ4c4lp5sXZd7bpGHAw6ARkHUeXQxD1cAW4-X1x0qtj_AN0mukqEOl4 nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMkmOm
Y6UOwJXIJY9-G1ELK-RQWrKH_StR-AM9H7GpKmSEji8QYOcMOjr-u9H1Lt_pBEie kkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZjDYENR
G802SxWz0rbFTXRcj4BWLxcpCtjUZ31AP-sc-L_eCZ5UNl0aSRNqFskuPkzRsFZR WiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfEJmNmfsx5f
DJqSSJeVOyJ7pZCQ83fli19Vgi_3R7XMUqluQuuc7ZHOWixi47jXlBTlWRZ5iFxa cB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWyEHW6WzQ4iH9S
S8G6J8wUrd4BKggAw3qX5XoIfXQVlQZE0Vmkq_zQSIo5LnFKyowooRcdsEuNh9B9 IcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_NSsx24LxtK6fIkej
Mkyt0ZQElG-jGdtHWjZSOA. RlMBmCfxv0Tg8CtxpURigg.
AxY8DCtDaGlsbGljb3RoZQ. AxY8DCtDaGlsbGljb3RoZQ.
1eBWFgcrz40wC88cgv8rPgu3EfmC1p4zT0kIxxfSF2zDJcQ-iEHk1jQM95xAdr5Z. KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.
RBGhYzE8_cZLHjJqqHuLhzbgWgL_wV3LDSUrcbkOiIA fY2U_Hx5VcfXmipEldHhMA
See Appendix A.2 for the complete details of computing this JWE. See Appendix A.2 for the complete details of computing this JWE.
4. JWE Header 4. JWE Header
The members of the JSON object represented by the JWE Header describe The members of the JSON object represented by the JWE Header describe
the encryption applied to the Plaintext and optionally additional the encryption applied to the Plaintext and optionally additional
properties of the JWE. The Header Parameter Names within this object properties of the JWE. The Header Parameter Names within this object
MUST be unique; JWEs with duplicate Header Parameter Names MUST be MUST be unique; JWEs with duplicate Header Parameter Names MUST be
rejected. Implementations MUST understand the entire contents of the rejected.
header; otherwise, the JWE 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 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) or a JWE Header. The first is by examining the "alg" (algorithm)
header value. If the value represents a digital signature or MAC header parameter value. If the value represents a digital signature
algorithm, or is the value "none", it is for a JWS; if it represents or MAC algorithm, or is the value "none", it is for a JWS; if it
an encryption or key agreement algorithm, it is for a JWE. A second represents a Key Encryption, Key Wrapping, Direct Key Agreement, Key
method is determining whether an "enc" (encryption method) member Agreement with Key Wrapping, or Direct Encryption algorithm, it is
exists. If the "enc" member exists, it is a JWE; otherwise, it is a for a JWE. A second method is determining whether an "enc"
JWS. Both methods will yield the same result for all legal input (encryption method) member exists. If the "enc" member exists, it is
values. 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 There are three classes of Header Parameter Names: Reserved Header
Parameter Names, Public Header Parameter Names, and Private Header Parameter Names, Public Header Parameter Names, and Private Header
Parameter Names. Parameter Names.
4.1. Reserved Header Parameter Names 4.1. Reserved Header Parameter Names
The following Header Parameter Names are reserved with meanings as The following Header Parameter Names are reserved with meanings as
defined below. All the names are short because a core goal of JWE is defined below. All the names are short because a core goal of this
for the representations to be compact. specification is for the resulting representations using the JWE
Compact Serialization to be compact.
Additional reserved Header Parameter Names MAY be defined via the Additional reserved Header Parameter Names MAY be defined via the
IANA JSON Web Signature and Encryption Header Parameters registry IANA JSON Web Signature and Encryption Header Parameters registry
[JWS]. As indicated by the common registry, JWSs and JWEs share a [JWS]. As indicated by the common registry, JWSs and JWEs share a
common header parameter space; when a parameter is used by both common header parameter space; when a parameter is used by both
specifications, its usage must be compatible between the specifications, its usage must be compatible between the
specifications. specifications.
4.1.1. "alg" (Algorithm) Header Parameter 4.1.1. "alg" (Algorithm) Header Parameter
The "alg" (algorithm) header parameter identifies the cryptographic The "alg" (algorithm) header parameter identifies the cryptographic
algorithm used to encrypt or determine the value of the Content algorithm used to encrypt or determine the value of the Content
Master Key (CMK). The algorithm specified by the "alg" value MUST be Encryption Key (CEK). The algorithm specified by the "alg" value
supported by the implementation and there MUST be a key for use with MUST be supported by the implementation and there MUST be a key for
that algorithm associated with the intended recipient or the JWE MUST use with that algorithm associated with the intended recipient or the
be rejected. "alg" values SHOULD either be registered in the IANA JWE MUST be rejected. "alg" values SHOULD either be registered in the
JSON Web Signature and Encryption Algorithms registry [JWA] or be a IANA JSON Web Signature and Encryption Algorithms registry [JWA] or
value that contains a Collision Resistant Namespace. The "alg" value be a value that contains a Collision Resistant Namespace. The "alg"
is a case sensitive string containing a StringOrURI value. Use of value is a case sensitive string containing a StringOrURI value. Use
this header parameter is REQUIRED. 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 A list of defined "alg" values can be found in the IANA JSON Web
Signature and Encryption Algorithms registry [JWA]; the initial Signature and Encryption Algorithms registry [JWA]; the initial
contents of this registry are the values defined in Section 4.1 of contents of this registry are the values defined in Section 4.1 of
the JSON Web Algorithms (JWA) [JWA] specification. the JSON Web Algorithms (JWA) [JWA] specification.
4.1.2. "enc" (Encryption Method) Header Parameter 4.1.2. "enc" (Encryption Method) Header Parameter
The "enc" (encryption method) header parameter identifies the block The "enc" (encryption method) header parameter identifies the block
encryption algorithm used to encrypt the Plaintext to produce the encryption algorithm used to encrypt the Plaintext to produce the
Ciphertext. This algorithm MUST be an Authenticated Encryption Ciphertext. This algorithm MUST be an Authenticated Encryption
algorithm with a specified key length. The algorithm specified by algorithm with a specified key length. The algorithm specified by
the "enc" value MUST be supported by the implementation or the JWE the "enc" value MUST be supported by the implementation or the JWE
MUST be rejected. "enc" values SHOULD either be registered in the MUST be rejected. "enc" values SHOULD either be registered in the
IANA JSON Web Signature and Encryption Algorithms registry [JWA] or IANA JSON Web Signature and Encryption Algorithms registry [JWA] or
be a value that contains a Collision Resistant Namespace. The "enc" be a value that contains a Collision Resistant Namespace. The "enc"
value is a case sensitive string containing a StringOrURI value. Use value is a case sensitive string containing a StringOrURI value. Use
of this header parameter is REQUIRED. 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 A list of defined "enc" values can be found in the IANA JSON Web
Signature and Encryption Algorithms registry [JWA]; the initial Signature and Encryption Algorithms registry [JWA]; the initial
contents of this registry are the values defined in Section 4.2 of contents of this registry are the values defined in Section 4.2 of
the JSON Web Algorithms (JWA) [JWA] specification. the JSON Web Algorithms (JWA) [JWA] specification.
4.1.3. "epk" (Ephemeral Public Key) Header Parameter 4.1.3. "epk" (Ephemeral Public Key) Header Parameter
The "epk" (ephemeral public key) value created by the originator for The "epk" (ephemeral public key) value created by the originator for
the use in key agreement algorithms. This key is represented as a the use in key agreement algorithms. This key is represented as a
JSON Web Key [JWK] value. Use of this header parameter is OPTIONAL, JSON Web Key [JWK] value. Use of this header parameter is OPTIONAL,
although its use is REQUIRED with some "alg" algorithms. although its use is REQUIRED with some "alg" algorithms. When its
use is REQUIRED, this header parameter MUST be understood by
implementations.
4.1.4. "zip" (Compression Algorithm) Header Parameter 4.1.4. "zip" (Compression Algorithm) Header Parameter
The "zip" (compression algorithm) applied to the Plaintext before The "zip" (compression algorithm) applied to the Plaintext before
encryption, if any. If present, the value of the "zip" header encryption, if any. If present, the value of the "zip" header
parameter MUST be the case sensitive string "DEF". Compression is parameter MUST be the case sensitive string "DEF". Compression is
performed with the DEFLATE [RFC1951] algorithm. If no "zip" performed with the DEFLATE [RFC1951] algorithm. If no "zip"
parameter is present, no compression is applied to the Plaintext parameter is present, no compression is applied to the Plaintext
before encryption. Use of this header parameter is OPTIONAL. before encryption. Use of this header parameter is OPTIONAL. This
header parameter MUST be understood by implementations.
4.1.5. "jku" (JWK Set URL) Header Parameter 4.1.5. "jku" (JWK Set URL) Header Parameter
The "jku" (JWK Set URL) header parameter is a URI [RFC3986] that 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 refers to a resource for a set of JSON-encoded public keys, one of
which corresponds to the key used to encrypt the JWE; this can be which is the key to which the JWE was encrypted; this can be used to
used to determine the private key needed to decrypt the JWE. The determine the private key needed to decrypt the JWE. The keys MUST
keys MUST be encoded as a JSON Web Key Set (JWK Set) [JWK]. The be encoded as a JSON Web Key Set (JWK Set) [JWK]. The protocol used
protocol used to acquire the resource MUST provide integrity to acquire the resource MUST provide integrity protection; an HTTP
protection; an HTTP GET request to retrieve the certificate MUST use GET request to retrieve the certificate MUST use TLS [RFC2818]
TLS [RFC2818] [RFC5246]; the identity of the server MUST be [RFC5246]; the identity of the server MUST be validated, as per
validated, as per Section 3.1 of HTTP Over TLS [RFC2818]. Use of Section 3.1 of HTTP Over TLS [RFC2818]. Use of this header parameter
this header parameter is OPTIONAL. is OPTIONAL.
4.1.6. "jwk" (JSON Web Key) Header Parameter 4.1.6. "jwk" (JSON Web Key) Header Parameter
The "jwk" (JSON Web Key) header parameter is a public key that The "jwk" (JSON Web Key) header parameter is the public key to which
corresponds to the key used to encrypt the JWE; this can be used to the JWE was encrypted; this can be used to determine the private key
determine the private key needed to decrypt the JWE. This key is needed to decrypt the JWE. This key is represented as a JSON Web Key
represented as a JSON Web Key [JWK]. Use of this header parameter is [JWK]. Use of this header parameter is OPTIONAL.
OPTIONAL.
4.1.7. "x5u" (X.509 URL) Header Parameter 4.1.7. "x5u" (X.509 URL) Header Parameter
The "x5u" (X.509 URL) header parameter is a URI [RFC3986] that refers 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 to a resource for the X.509 public key certificate or certificate
chain [RFC5280] corresponding to the key used to encrypt the JWE; chain [RFC5280] containing the key to which the JWE was encrypted;
this can be used to determine the private key needed to decrypt the this can be used to determine the private key needed to decrypt the
JWE. The identified resource MUST provide a representation of the JWE. The identified resource MUST provide a representation of the
certificate or certificate chain that conforms to RFC 5280 [RFC5280] certificate or certificate chain that conforms to RFC 5280 [RFC5280]
in PEM encoded form [RFC1421]. The certificate containing the public in PEM encoded form [RFC1421]. The certificate containing the public
key of the entity that encrypted the JWE MUST be the first key to which the JWE was encrypted MUST be the first certificate.
certificate. This MAY be followed by additional certificates, with This MAY be followed by additional certificates, with each subsequent
each subsequent certificate being the one used to certify the certificate being the one used to certify the previous one. The
previous one. The protocol used to acquire the resource MUST provide protocol used to acquire the resource MUST provide integrity
integrity protection; an HTTP GET request to retrieve the certificate protection; an HTTP GET request to retrieve the certificate MUST use
MUST use TLS [RFC2818] [RFC5246]; the identity of the server MUST be TLS [RFC2818] [RFC5246]; the identity of the server MUST be
validated, as per Section 3.1 of HTTP Over TLS [RFC2818]. Use of validated, as per Section 3.1 of HTTP Over TLS [RFC2818]. Use of
this header parameter is OPTIONAL. this header parameter is OPTIONAL.
4.1.8. "x5t" (X.509 Certificate Thumbprint) Header Parameter 4.1.8. "x5t" (X.509 Certificate Thumbprint) Header Parameter
The "x5t" (X.509 Certificate Thumbprint) header parameter provides a The "x5t" (X.509 Certificate Thumbprint) header parameter provides a
base64url encoded SHA-1 thumbprint (a.k.a. digest) of the DER base64url encoded SHA-1 thumbprint (a.k.a. digest) of the DER
encoding of the X.509 certificate [RFC5280] corresponding to the key encoding of the X.509 certificate [RFC5280] containing the key to
used to encrypt the JWE; this can be used to determine the private which the JWE was encrypted; this can be used to determine the
key needed to decrypt the JWE. Use of this header parameter is private key needed to decrypt the JWE. Use of this header parameter
OPTIONAL. is OPTIONAL.
If, in the future, certificate thumbprints need to be computed using If, in the future, certificate thumbprints need to be computed using
hash functions other than SHA-1, it is suggested that additional hash functions other than SHA-1, it is suggested that additional
related header parameters be defined for that purpose. For example, related header parameters be defined for that purpose. For example,
it is suggested that a new "x5t#S256" (X.509 Certificate Thumbprint it is suggested that a new "x5t#S256" (X.509 Certificate Thumbprint
using SHA-256) header parameter could be defined by registering it in using SHA-256) header parameter could be defined by registering it in
the IANA JSON Web Signature and Encryption Header Parameters registry the IANA JSON Web Signature and Encryption Header Parameters registry
[JWS]. [JWS].
4.1.9. "x5c" (X.509 Certificate Chain) Header Parameter 4.1.9. "x5c" (X.509 Certificate Chain) Header Parameter
The "x5c" (X.509 Certificate Chain) header parameter contains the The "x5c" (X.509 Certificate Chain) header parameter contains the
X.509 public key certificate or certificate chain [RFC5280] X.509 public key certificate or certificate chain [RFC5280]
corresponding to the key used to encrypt the JWE; this can be used to containing the key to which the JWE was encrypted; this can be used
determine the private key needed to decrypt the JWE. The certificate to determine the private key needed to decrypt the JWE. The
or certificate chain is represented as an array of certificate value certificate or certificate chain is represented as an array of
strings. Each string is a base64 encoded ([RFC4648] Section 4 -- not certificate value strings. Each string is a base64 encoded
base64url encoded) DER [ITU.X690.1994] PKIX certificate value. The ([RFC4648] Section 4 -- not base64url encoded) DER [ITU.X690.1994]
certificate containing the public key of the entity that encrypted PKIX certificate value. The certificate containing the public key to
the JWE MUST be the first certificate. This MAY be followed by which the JWE was encrypted MUST be the first certificate. This MAY
additional certificates, with each subsequent certificate being the be followed by additional certificates, with each subsequent
one used to certify the previous one. The recipient MUST verify the certificate being the one used to certify the previous one. Use of
certificate chain according to [RFC5280] and reject the JWE if any this header parameter is OPTIONAL.
validation failure occurs. Use of this header parameter is OPTIONAL.
See Appendix B of [JWS] for an example "x5c" value. See Appendix B of [JWS] for an example "x5c" value.
4.1.10. "kid" (Key ID) Header Parameter 4.1.10. "kid" (Key ID) Header Parameter
The "kid" (key ID) header parameter is a hint indicating which key The "kid" (key ID) header parameter is a hint indicating which key to
was used to encrypt the JWE; this can be used to determine the which the JWE was encrypted; this can be used to determine the
private key needed to decrypt the JWE. This parameter allows private key needed to decrypt the JWE. This parameter allows
originators to explicitly signal a change of key to recipients. originators to explicitly signal a change of key to recipients.
Should the recipient be unable to locate a key corresponding to the Should the recipient be unable to locate a key corresponding to the
"kid" value, they SHOULD treat that condition as an error. The "kid" value, they SHOULD treat that condition as an error. The
interpretation of the "kid" value is unspecified. Its value MUST be interpretation of the "kid" value is unspecified. Its value MUST be
a string. Use of this header parameter is OPTIONAL. a string. Use of this header parameter is OPTIONAL.
When used with a JWK, the "kid" value MAY be used to match a JWK When used with a JWK, the "kid" value can be used to match a JWK
"kid" parameter value. "kid" parameter value.
4.1.11. "typ" (Type) Header Parameter 4.1.11. "typ" (Type) Header Parameter
The "typ" (type) header parameter is used to declare the type of this The "typ" (type) header parameter is used to declare the type of this
object. The type value "JWE" MAY be used to indicate that this object. The type value "JWE" is used to indicate that this object is
object is a JWE. The "typ" value is a case sensitive string. Use of 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. this header parameter is OPTIONAL.
MIME Media Type [RFC2046] values MAY be used as "typ" values. MIME Media Type [RFC2046] values MAY be used as "typ" values.
"typ" values SHOULD either be registered in the IANA JSON Web "typ" values SHOULD either be registered in the IANA JSON Web
Signature and Encryption Type Values registry [JWS] or be a value Signature and Encryption Type Values registry [JWS] or be a value
that contains a Collision Resistant Namespace. that contains a Collision Resistant Namespace.
4.1.12. "cty" (Content Type) Header Parameter 4.1.12. "cty" (Content Type) Header Parameter
The "cty" (content type) header parameter is used to declare the type The "cty" (content type) header parameter is used to declare the type
of the encrypted content (the Plaintext). The "cty" value is a case of the encrypted content (the Plaintext). For example, the JSON Web
sensitive string. Use of this header parameter is OPTIONAL. 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 The values used for the "cty" header parameter come from the same
value space as the "typ" header parameter, with the same rules value space as the "typ" header parameter, with the same rules
applying. applying.
4.1.13. "apu" (Agreement PartyUInfo) Header Parameter 4.1.13. "apu" (Agreement PartyUInfo) Header Parameter
The "apu" (agreement PartyUInfo) value for key agreement algorithms The "apu" (agreement PartyUInfo) value for key agreement algorithms
using it (such as "ECDH-ES"), represented as a base64url encoded using it (such as "ECDH-ES"), represented as a base64url encoded
string. Use of this header parameter is OPTIONAL. 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.
4.1.14. "apv" (Agreement PartyVInfo) Header Parameter 4.1.14. "apv" (Agreement PartyVInfo) Header Parameter
The "apv" (agreement PartyVInfo) value for key agreement algorithms The "apv" (agreement PartyVInfo) value for key agreement algorithms
using it (such as "ECDH-ES"), represented as a base64url encoded using it (such as "ECDH-ES"), represented as a base64url encoded
string. Use of this header parameter is OPTIONAL. 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.
4.1.15. "epu" (Encryption PartyUInfo) Header Parameter 4.1.15. "crit" (Critical) Header Parameter
The "epu" (encryption PartyUInfo) value for plaintext encryption The "crit" (critical) header parameter is array listing the names of
algorithms using it (such as "A128CBC+HS256"), represented as a header parameters that are present in the JWE Header that MUST be
base64url encoded string. Use of this header parameter is OPTIONAL. 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.
4.1.16. "epv" (Encryption PartyVInfo) Header Parameter An example use, along with a hypothetical "exp" (expiration-time)
field is:
The "epv" (encryption PartyVInfo) value for plaintext encryption {"alg":"RSA-OAEP",
algorithms using it (such as "A128CBC+HS256"), represented as a "enc":"A256GCM",
base64url encoded string. Use of this header parameter is OPTIONAL. "crit":["exp"],
"exp":1363284000
}
4.2. Public Header Parameter Names 4.2. Public Header Parameter Names
Additional Header Parameter Names can be defined by those using JWEs. Additional Header Parameter Names can be defined by those using JWEs.
However, in order to prevent collisions, any new Header Parameter However, in order to prevent collisions, any new Header Parameter
Name SHOULD either be registered in the IANA JSON Web Signature and Name SHOULD either be registered in the IANA JSON Web Signature and
Encryption Header Parameters registry [JWS] or be a Public Name: a Encryption Header Parameters registry [JWS] or be a Public Name: a
value that contains a Collision Resistant Namespace. In each case, value that contains a Collision Resistant Namespace. In each case,
the definer of the name or value needs to take reasonable precautions 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 to make sure they are in control of the part of the namespace they
skipping to change at page 16, line 47 skipping to change at page 17, line 16
caution. caution.
5. Producing and Consuming JWEs 5. Producing and Consuming JWEs
5.1. Message Encryption 5.1. Message Encryption
The message encryption process is as follows. The order of the steps The message encryption process is as follows. The order of the steps
is not significant in cases where there are no dependencies between is not significant in cases where there are no dependencies between
the inputs and outputs of the steps. the inputs and outputs of the steps.
1. When key wrapping, key encryption, or key agreement with key 1. Determine the Key Management Mode employed by the algorithm used
wrapping are employed, generate a random Content Master Key to determine the Content Encryption Key (CEK) value. (This is
(CMK). See RFC 4086 [RFC4086] for considerations on generating the algorithm recorded in the "alg" (algorithm) header parameter
random values. The CMK MUST have a length equal to that of the resulting JWE.)
required for the block encryption algorithm.
2. When key agreement is employed, use the key agreement algorithm 2. When Key Wrapping, Key Encryption, or Key Agreement with Key
to compute the value of the agreed upon key. When key agreement Wrapping are employed, generate a random Content Encryption Key
without key wrapping is employed, let the Content Master Key (CEK) value. See RFC 4086 [RFC4086] for considerations on
(CMK) be the agreed upon key. When key agreement with key generating random values. The CEK MUST have a length equal to
wrapping is employed, the agreed upon key will be used to wrap that required for the block encryption algorithm.
the CMK.
3. When key wrapping, key encryption, or key agreement with key 3. When Direct Key Agreement or Key Agreement with Key Wrapping are
wrapping are employed, encrypt the CMK for the recipient (see employed, use the key agreement algorithm to compute the value
of the agreed upon key. When Direct Key Agreement is employed,
let the Content Encryption Key (CEK) be the agreed upon key.
When Key Agreement with Key Wrapping is employed, the agreed
upon key will be used to wrap the CEK.
4. When Key Wrapping, Key Encryption, or Key Agreement with Key
Wrapping are employed, encrypt the CEK to the recipient (see
Section 6.1) and let the result be the JWE Encrypted Key. Section 6.1) and let the result be the JWE Encrypted Key.
Otherwise, when direct encryption with a shared or agreed upon
symmetric key is employed, let the JWE Encrypted Key be the
empty byte array.
4. When direct encryption with a shared symmetric key is employed, 5. Otherwise, when Direct Key Agreement or Direct Encryption are
let the Content Master Key (CMK) be the shared key. employed, let the JWE Encrypted Key be the empty octet sequence.
5. Base64url encode the JWE Encrypted Key to create the Encoded JWE 6. When Direct Encryption is employed, let the Content Encryption
Key (CEK) be the shared symmetric key.
7. Base64url encode the JWE Encrypted Key to create the Encoded JWE
Encrypted Key. Encrypted Key.
6. Generate a random JWE Initialization Vector of the correct size 8. Generate a random JWE Initialization Vector of the correct size
for the block encryption algorithm (if required for the for the block encryption algorithm (if required for the
algorithm); otherwise, let the JWE Initialization Vector be the algorithm); otherwise, let the JWE Initialization Vector be the
empty byte string. empty octet sequence.
7. Base64url encode the JWE Initialization Vector to create the 9. Base64url encode the JWE Initialization Vector to create the
Encoded JWE Initialization Vector. Encoded JWE Initialization Vector.
8. Compress the Plaintext if a "zip" parameter was included. 10. Compress the Plaintext if a "zip" parameter was included.
9. Serialize the (compressed) Plaintext into a byte sequence M. 11. Serialize the (compressed) Plaintext into an octet sequence M.
10. Create a JWE Header containing the encryption parameters used. 12. Create a JWE Header containing the encryption parameters used.
Note that white space is explicitly allowed in the Note that white space is explicitly allowed in the
representation and no canonicalization need be performed before representation and no canonicalization need be performed before
encoding. encoding.
11. Base64url encode the bytes of the UTF-8 representation of the 13. Base64url encode the octets of the UTF-8 representation of the
JWE Header to create the Encoded JWE Header. JWE Header to create the Encoded JWE Header.
12. Let the "additional authenticated data" value be the bytes of 14. Let the Additional Authenticated Data value be the octets of the
the ASCII representation of the concatenation of the Encoded JWE ASCII representation of the concatenation of the Encoded JWE
Header, a period ('.') character, the Encoded JWE Encrypted Key, Header, a period ('.') character, and the Encoded JWE Encrypted
a second period character ('.'), and the Encoded JWE Key.
Initialization Vector.
13. Encrypt M using the CMK, the JWE Initialization Vector, and the 15. Encrypt M using the CEK, the JWE Initialization Vector, and the
"additional authenticated data" value using the specified block Additional Authenticated Data value using the specified block
encryption algorithm to create the JWE Ciphertext value and the encryption algorithm to create the JWE Ciphertext value and the
JWE Integrity Value (which is the "authentication tag" output JWE Authentication Tag (which is the Authentication Tag output
from the calculation). from the calculation).
14. Base64url encode the JWE Ciphertext to create the Encoded JWE 16. Base64url encode the JWE Ciphertext to create the Encoded JWE
Ciphertext. Ciphertext.
15. Base64url encode the JWE Integrity Value to create the Encoded 17. Base64url encode the JWE Authentication Tag to create the
JWE Integrity Value. Encoded JWE Authentication Tag.
16. The five encoded parts, taken together, are the result. 18. The five encoded parts are the result values used in both the
JWE Compact Serialization and the JWE JSON Serialization
representations.
17. The Compact Serialization of this result is the concatenation of 19. If the JWE JSON Serialization is being used, repeat this process
the Encoded JWE Header, the Encoded JWE Encrypted Key, the for each recipient.
Encoded JWE Initialization Vector, the Encoded JWE Ciphertext,
and the Encoded JWE Integrity Value in that order, with the five 20. Create the desired serialized output. The JWE Compact
strings being separated by four period ('.') characters. 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
JWE JSON Serialization is described in Section 7.
5.2. Message Decryption 5.2. Message Decryption
The message decryption process is the reverse of the encryption The message decryption process is the reverse of the encryption
process. The order of the steps is not significant in cases where process. The order of the steps is not significant in cases where
there are no dependencies between the inputs and outputs of the there are no dependencies between the inputs and outputs of the
steps. If any of these steps fails, the JWE MUST be rejected. steps. If any of these steps fails, the JWE MUST be rejected.
1. Determine the Encoded JWE Header, the Encoded JWE Encrypted Key, 1. Parse the serialized input to determine the values of the
the Encoded JWE Initialization Vector, the Encoded JWE Encoded JWE Header, the Encoded JWE Encrypted Key, the Encoded
Ciphertext, and the Encoded JWE Integrity Value values contained JWE Initialization Vector, the Encoded JWE Ciphertext, and the
in the JWE. When using the Compact Serialization, these five Encoded JWE Authentication Tag. When using the JWE Compact
values are represented in that order, separated by four period Serialization, these five values are represented as text strings
('.') characters. in that order, separated by four period ('.') characters. The
JWE JSON Serialization is described in Section 7.
2. The Encoded JWE Header, the Encoded JWE Encrypted Key, the 2. The Encoded JWE Header, the Encoded JWE Encrypted Key, the
Encoded JWE Initialization Vector, the Encoded JWE Ciphertext, Encoded JWE Initialization Vector, the Encoded JWE Ciphertext,
and the Encoded JWE Integrity Value MUST be successfully and the Encoded JWE Authentication Tag MUST be successfully
base64url decoded following the restriction that no padding base64url decoded following the restriction that no padding
characters have been used. characters have been used.
3. The resulting JWE Header MUST be completely valid JSON syntax 3. The resulting JWE Header MUST be completely valid JSON syntax
conforming to RFC 4627 [RFC4627]. conforming to RFC 4627 [RFC4627].
4. The resulting JWE Header MUST be validated to only include 4. The resulting JWE Header MUST be validated to only include
parameters and values whose syntax and semantics are both parameters and values whose syntax and semantics are both
understood and supported. understood and supported or that are specified as being ignored
when not understood.
5. Verify that the JWE uses a key known to the recipient. 5. Determine the Key Management Mode employed by the algorithm
specified by the "alg" (algorithm) header parameter.
6. When key agreement is employed, use the key agreement algorithm 6. Verify that the JWE uses a key known to the recipient.
to compute the value of the agreed upon key. When key agreement
without key wrapping is employed, let the Content Master Key
(CMK) be the agreed upon key. When key agreement with key
wrapping is employed, the agreed upon key will be used to
decrypt the JWE Encrypted Key.
7. When key wrapping, key encryption, or key agreement with key 7. When Direct Key Agreement or Key Agreement with Key Wrapping are
wrapping are employed, decrypt the JWE Encrypted Key to produce employed, use the key agreement algorithm to compute the value
the Content Master Key (CMK). The CMK MUST have a length equal of the agreed upon key. When Direct Key Agreement is employed,
to that required for the block encryption algorithm. let the Content Encryption Key (CEK) be the agreed upon key.
When Key Agreement with Key Wrapping is employed, the agreed
upon key will be used to decrypt the JWE Encrypted Key.
8. When direct encryption with a shared symmetric key is employed, 8. When Key Wrapping, Key Encryption, or Key Agreement with Key
let the Content Master Key (CMK) be the shared key. Wrapping are employed, decrypt the JWE Encrypted Key to produce
the Content Encryption Key (CEK). The CEK MUST have a length
equal to that required for the block encryption algorithm. To
mitigate against attacks described in RFC 3218 [RFC3218], the
recipient MUST NOT distinguish between format, padding, and
length errors of encrypted keys. It is strongly recommended, in
the event of receiving an improperly formatted key, that the
receiver substitute a randomly generated CEK and proceed to the
next step, to mitigate timing attacks.
9. Let the "additional authenticated data" value be the bytes of 9. Otherwise, when Direct Key Agreement or Direct Encryption are
the ASCII representation of the concatenation of the Encoded JWE employed, verify that the JWE Encrypted Key value is empty octet
Header, a period ('.') character, the Encoded JWE Encrypted Key, sequence.
a second period character ('.'), and the Encoded JWE
Initialization Vector.
10. Decrypt the JWE Ciphertext using the CMK, the JWE Initialization 10. When Direct Encryption is employed, let the Content Encryption
Vector, the "additional authenticated data" value, and the JWE Key (CEK) be the shared symmetric key.
Integrity Value (which is the "authentication tag" input to the
11. Let the Additional Authenticated Data value be the octets of the
ASCII representation of the concatenation of the Encoded JWE
Header, a period ('.') character, and the Encoded JWE Encrypted
Key.
12. Decrypt the JWE Ciphertext using the CEK, the JWE Initialization
Vector, the Additional Authenticated Data value, and the JWE
Authentication Tag (which is the Authentication Tag input to the
calculation) using the specified block encryption algorithm, calculation) using the specified block encryption algorithm,
returning the decrypted plaintext and verifying the JWE returning the decrypted plaintext and verifying the JWE
Integrity Value in the manner specified for the algorithm, Authentication Tag in the manner specified for the algorithm,
rejecting the input without emitting any decrypted output if the rejecting the input without emitting any decrypted output if the
JWE Integrity Value is incorrect. JWE Authentication Tag is incorrect.
11. Uncompress the decrypted plaintext if a "zip" parameter was 13. Uncompress the decrypted plaintext if a "zip" parameter was
included. included.
12. Output the resulting Plaintext. 14. Output the resulting Plaintext.
15. If the JWE JSON Serialization is being used, repeat this process
for each recipient contained in the representation.
5.3. String Comparison Rules 5.3. String Comparison Rules
Processing a JWE inevitably requires comparing known strings to Processing a JWE inevitably requires comparing known strings to
values in JSON objects. For example, in checking what the encryption values in JSON objects. For example, in checking what the encryption
method is, the Unicode string encoding "enc" will be checked against 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 the member names in the JWE Header to see if there is a matching
Header Parameter Name. Header Parameter Name.
Comparisons between JSON strings and other Unicode strings MUST be Comparisons between JSON strings and other Unicode strings MUST be
performed by comparing Unicode code points without normalization as performed by comparing Unicode code points without normalization as
specified in the String Comparison Rules in Section 5.3 of [JWS]. specified in the String Comparison Rules in Section 5.3 of [JWS].
6. Encrypting JWEs with Cryptographic Algorithms 6. Encrypting JWEs with Cryptographic Algorithms
JWE uses cryptographic algorithms to encrypt the Plaintext and the JWE uses cryptographic algorithms to encrypt the Plaintext and the
Content Encryption Key (CMK) and to provide integrity protection for Content Encryption Key (CEK) and to provide integrity protection for
the JWE Header, JWE Encrypted Key, and JWE Ciphertext. The JSON Web the JWE Header, JWE Encrypted Key, and JWE Ciphertext. The JSON Web
Algorithms (JWA) [JWA] specification specifies a set of cryptographic Algorithms (JWA) [JWA] specification specifies a set of cryptographic
algorithms and identifiers to be used with this specification and algorithms and identifiers to be used with this specification and
defines registries for additional such algorithms. Specifically, defines registries for additional such algorithms. Specifically,
Section 4.1 specifies a set of "alg" (algorithm) header parameter Section 4.1 specifies a set of "alg" (algorithm) header parameter
values and Section 4.2 specifies a set of "enc" (encryption method) values and Section 4.2 specifies a set of "enc" (encryption method)
header parameter values intended for use this specification. It also header parameter values intended for use this specification. It also
describes the semantics and operations that are specific to these describes the semantics and operations that are specific to these
algorithms. algorithms.
Public keys employed for encryption can be identified using the Public keys employed for encryption can be identified using the
Header Parameter methods described in Section 4.1 or can be Header Parameter methods described in Section 4.1 or can be
distributed using methods that are outside the scope of this distributed using methods that are outside the scope of this
specification. specification.
6.1. CMK Encryption 6.1. CEK Encryption
JWE supports three forms of Content Master Key (CMK) encryption: JWE supports three forms of Content Encryption Key (CEK) encryption:
o Asymmetric encryption under the recipient's public key. o Asymmetric encryption under the recipient's public key.
o Symmetric encryption under a key shared between the sender and o Symmetric encryption under a key shared between the sender and
receiver. receiver.
o Symmetric encryption under a key agreed upon between the sender o Symmetric encryption under a key agreed upon between the sender
and receiver. and receiver.
See the algorithms registered for "enc" usage in the IANA JSON Web See the algorithms registered for "enc" usage in the IANA JSON Web
Signature and Encryption Algorithms registry [JWA] and Section 4.1 of Signature and Encryption Algorithms registry [JWA] and Section 4.1 of
the JSON Web Algorithms (JWA) [JWA] specification for lists of the JSON Web Algorithms (JWA) [JWA] specification for lists of
encryption algorithms that can be used for CMK encryption. encryption algorithms that can be used for CEK encryption.
7. IANA Considerations 7. JSON Serialization
7.1. Registration of JWE Header Parameter Names 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, and a "ciphertext"
member containing a shared Encoded JWE Ciphertext value. Each member
of the "recipients" array is a JSON object with a "header" member
containing an Encoded JWE Header value, an "encrypted_key" member
containing an Encoded JWE Encrypted Key value, and an
"authentication_tag" member containing an Encoded JWE Authentication
Tag value.
Unlike the JWE Compact Serialization, content using the JWE JSON
Serialization MAY be encrypted to more than one recipient. Each
recipient requires:
o a JWE Header value specifying the cryptographic parameters used to
encrypt the JWE Encrypted Key to that recipient and the parameters
used to encrypt the plaintext to produce the JWE Ciphertext; this
is represented as an Encoded JWE Header value in the "header"
member of an object in the "recipients" array.
o a JWE Encrypted Key value used to encrypt the ciphertext; this is
represented as an Encoded JWE Encrypted Key value in the
"encrypted_key" member of the same object in the "recipients"
array.
o a JWE Authentication Tag that ensures the integrity of the
Ciphertext and the parameters used to create it; this is
represented as an Encoded JWE Authentication Tag value in the
"authentication_tag" member of the same object in the "recipients"
array.
Therefore, the syntax is:
{"recipients":[
{"header":"<header 1 contents>",
"encrypted_key":"<encrypted key 1 contents>",
"authentication_tag":"<authentication tag 1 contents>"},
...
{"header":"<header N contents>",
"encrypted_key":"<encrypted key N contents>",
"authentication_tag":"<authentication tag N contents>"}],
"initialization_vector":"<initialization vector contents>",
"ciphertext":"<ciphertext 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", "encrypted_key",
and "authentication_tag" value being created and validated together.
Each JWE Encrypted Key value and the corresponding JWE Authentication
Tag are computed using the parameters of the corresponding JWE Header
value in the same manner as for the JWE Compact Serialization. This
has the desirable result that each Encoded JWE Encrypted Key value in
the "recipients" array and each Encoded JWE Authentication Tag in the
same array element are identical to the values that would have been
computed for the same parameters in the JWE Compact Serialization, as
are the shared JWE Ciphertext and JWE Initialization Vector values.
All recipients use the same JWE Ciphertext and JWE Initialization
Vector 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.
7.1. Example JWE-JS
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).
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",
"authentication_tag":
"fY2U_Hx5VcfXmipEldHhMA"},
{"header":
"eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0",
"encrypted_key":
"6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ",
"authentication_tag":
"CEH4ZS25HNrocFNPVN0SrA"}],
"initialization_vector":
"AxY8DCtDaGlsbGljb3RoZQ",
"ciphertext":
"KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY"
}
8. Implementation Considerations
The JWE Compact Serialization is mandatory to implement.
Implementation of the JWE JSON Serialization is OPTIONAL.
9. IANA Considerations
9.1. Registration of JWE Header Parameter Names
This specification registers the Header Parameter Names defined in This specification registers the Header Parameter Names defined in
Section 4.1 in the IANA JSON Web Signature and Encryption Header Section 4.1 in the IANA JSON Web Signature and Encryption Header
Parameters registry [JWS]. Parameters registry [JWS].
7.1.1. Registry Contents 9.1.1. Registry Contents
o Header Parameter Name: "alg" o Header Parameter Name: "alg"
o Header Parameter Usage Location(s): JWE o Header Parameter Usage Location(s): JWE
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1.1 of [[ this document ]] o Specification Document(s): Section 4.1.1 of [[ this document ]]
o Header Parameter Name: "enc" o Header Parameter Name: "enc"
o Header Parameter Usage Location(s): JWE o Header Parameter Usage Location(s): JWE
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1.2 of [[ this document ]] o Specification Document(s): Section 4.1.2 of [[ this document ]]
o Header Parameter Name: "epk" o Header Parameter Name: "epk"
o Header Parameter Usage Location(s): JWE o Header Parameter Usage Location(s): JWE
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1.3 of [[ this document ]] o Specification Document(s): Section 4.1.3 of [[ this document ]]
skipping to change at page 22, line 29 skipping to change at page 26, line 23
o Header Parameter Name: "apu" o Header Parameter Name: "apu"
o Header Parameter Usage Location(s): JWE o Header Parameter Usage Location(s): JWE
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1.13 of [[ this document ]] o Specification Document(s): Section 4.1.13 of [[ this document ]]
o Header Parameter Name: "apv" o Header Parameter Name: "apv"
o Header Parameter Usage Location(s): JWE o Header Parameter Usage Location(s): JWE
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1.14 of [[ this document ]] o Specification Document(s): Section 4.1.14 of [[ this document ]]
o Header Parameter Name: "epu" o Header Parameter Name: "crit"
o Header Parameter Usage Location(s): JWE o Header Parameter Usage Location(s): JWS
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1.15 of [[ this document ]] o Specification Document(s): Section 4.1.15 of [[ this document ]]
o Header Parameter Name: "epv" 9.2. JSON Web Signature and Encryption Type Values Registration
o Header Parameter Usage Location(s): JWE
o Change Controller: IETF
o Specification Document(s): Section 4.1.16 of [[ this document ]]
7.2. JSON Web Signature and Encryption Type Values Registration
7.2.1. Registry Contents 9.2.1. Registry Contents
This specification registers the "JWE" type value in the IANA JSON This specification registers the "JWE" and "JWE-JS" type values in
Web Signature and Encryption Type Values registry [JWS]: the IANA JSON Web Signature and Encryption Type Values registry
[JWS]:
o "typ" Header Parameter Value: "JWE" o "typ" Header Parameter Value: "JWE"
o Abbreviation for MIME Type: application/jwe o Abbreviation for MIME Type: application/jwe
o Change Controller: IETF o Change Controller: IETF
o Specification Document(s): Section 4.1.11 of [[ this document ]] o Specification Document(s): Section 4.1.11 of [[ this document ]]
7.3. Media Type Registration o "typ" Header Parameter Value: "JWE-JS"
o Abbreviation for MIME Type: application/jwe-js
o Change Controller: IETF
o Specification Document(s): Section 4.1.11 of [[ this document ]]
7.3.1. Registry Contents 9.3. Media Type Registration
This specification registers the "application/jwe" Media Type 9.3.1. Registry Contents
[RFC2046] in the MIME Media Type registry [RFC4288] to indicate that
the content is a JWE using the Compact Serialization. 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.
o Type Name: application o Type Name: application
o Subtype Name: jwe o Subtype Name: jwe
o Required Parameters: n/a o Required Parameters: n/a
o Optional Parameters: n/a o Optional Parameters: n/a
o Encoding considerations: JWE values are encoded as a series of o Encoding considerations: JWE values are encoded as a series of
base64url encoded values (some of which may be the empty string) base64url encoded values (some of which may be the empty string)
separated by period ('.') characters separated by period ('.') characters
o Security Considerations: See the Security Considerations section o Security Considerations: See the Security Considerations section
of this document of [[ this document ]]
o Interoperability Considerations: n/a o Interoperability Considerations: n/a
o Published Specification: [[ this document ]] o Published Specification: [[ this document ]]
o Applications that use this media type: OpenID Connect and other o Applications that use this media type: OpenID Connect and other
applications using encrypted JWTs applications using encrypted JWTs
o Additional Information: Magic number(s): n/a, File extension(s): o Additional Information: Magic number(s): n/a, File extension(s):
n/a, Macintosh file type code(s): n/a n/a, Macintosh file type code(s): n/a
o Person & email address to contact for further information: Michael o Person & email address to contact for further information: Michael
B. Jones, mbj@microsoft.com B. Jones, mbj@microsoft.com
o Intended Usage: COMMON o Intended Usage: COMMON
o Restrictions on Usage: none o Restrictions on Usage: none
o Author: Michael B. Jones, mbj@microsoft.com o Author: Michael B. Jones, mbj@microsoft.com
o Change Controller: IETF o Change Controller: IETF
8. Security Considerations o Type Name: application
o Subtype Name: jwe-js
o Required Parameters: n/a
o Optional Parameters: n/a
o Encoding considerations: JWE-JS values are represented as a JSON
Object; UTF-8 encoding SHOULD be employed for the JSON object.
o Security Considerations: See the Security Considerations section
of [[ this document ]]
o Interoperability Considerations: n/a
o Published Specification: [[ this document ]]
o Applications that use this media type: TBD
o Additional Information: Magic number(s): n/a, File extension(s):
n/a, Macintosh file type code(s): n/a
o Person & email address to contact for further information: Michael
B. Jones, mbj@microsoft.com
o Intended Usage: COMMON
o Restrictions on Usage: none
o Author: Michael B. Jones, mbj@microsoft.com
o Change Controller: IETF
10. Security Considerations
All of the security issues faced by any cryptographic application All of the security issues faced by any cryptographic application
must be faced by a JWS/JWE/JWK agent. Among these issues are must be faced by a JWS/JWE/JWK agent. Among these issues are
protecting the user's private and symmetric keys, preventing various protecting the user's private and symmetric keys, preventing various
attacks, and helping the user avoid mistakes such as inadvertently attacks, and helping the user avoid mistakes such as inadvertently
encrypting a message for the wrong recipient. The entire list of encrypting a message for the wrong recipient. The entire list of
security considerations is beyond the scope of this document. security considerations is beyond the scope of this document.
All the security considerations in the JWS specification also apply All the security considerations in the JWS specification also apply
to this specification. Likewise, all the security considerations in to this specification. Likewise, all the security considerations in
XML Encryption 1.1 [W3C.CR-xmlenc-core1-20120313] also apply to JWE, XML Encryption 1.1 [W3C.CR-xmlenc-core1-20120313] also apply, other
other than those that are XML specific. than those that are XML specific.
9. References When decrypting, particular care must be taken not to allow the JWE
9.1. Normative References 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.
AES GCM MUST NOT be used when using the JWE JSON Serialization for
multiple recipients, since this would result in the same
Initialization Vector and Plaintext values being used for multiple
GCM encryptions. This is prohibited by the GCM specification because
of severe security vulnerabilities that would result, were GCM used
in this way.
11. References
11.1. Normative References
[ITU.X690.1994] [ITU.X690.1994]
International Telecommunications Union, "Information International Telecommunications Union, "Information
Technology - ASN.1 encoding rules: Specification of Basic Technology - ASN.1 encoding rules: Specification of Basic
Encoding Rules (BER), Canonical Encoding Rules (CER) and Encoding Rules (BER), Canonical Encoding Rules (CER) and
Distinguished Encoding Rules (DER)", ITU-T Recommendation Distinguished Encoding Rules (DER)", ITU-T Recommendation
X.690, 1994. X.690, 1994.
[JWA] Jones, M., "JSON Web Algorithms (JWA)", [JWA] Jones, M., "JSON Web Algorithms (JWA)",
draft-ietf-jose-json-web-algorithms (work in progress), draft-ietf-jose-json-web-algorithms (work in progress),
December 2012. April 2013.
[JWK] Jones, M., "JSON Web Key (JWK)", [JWK] Jones, M., "JSON Web Key (JWK)",
draft-ietf-jose-json-web-key (work in progress), draft-ietf-jose-json-web-key (work in progress),
December 2012. April 2013.
[JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web [JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
Signature (JWS)", draft-ietf-jose-json-web-signature (work Signature (JWS)", draft-ietf-jose-json-web-signature (work
in progress), December 2012. in progress), April 2013.
[RFC1421] Linn, J., "Privacy Enhancement for Internet Electronic [RFC1421] Linn, J., "Privacy Enhancement for Internet Electronic
Mail: Part I: Message Encryption and Authentication Mail: Part I: Message Encryption and Authentication
Procedures", RFC 1421, February 1993. Procedures", RFC 1421, February 1993.
[RFC1951] Deutsch, P., "DEFLATE Compressed Data Format Specification [RFC1951] Deutsch, P., "DEFLATE Compressed Data Format Specification
version 1.3", RFC 1951, May 1996. version 1.3", RFC 1951, May 1996.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046, Extensions (MIME) Part Two: Media Types", RFC 2046,
skipping to change at page 25, line 4 skipping to change at page 29, line 40
10646", STD 63, RFC 3629, November 2003. 10646", STD 63, RFC 3629, November 2003.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005. RFC 3986, January 2005.
[RFC4086] Eastlake, D., Schiller, J., and S. Crocker, "Randomness [RFC4086] Eastlake, D., Schiller, J., and S. Crocker, "Randomness
Requirements for Security", BCP 106, RFC 4086, June 2005. Requirements for Security", BCP 106, RFC 4086, June 2005.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", BCP 13, RFC 4288, December 2005. Registration Procedures", RFC 4288, December 2005.
[RFC4627] Crockford, D., "The application/json Media Type for [RFC4627] Crockford, D., "The application/json Media Type for
JavaScript Object Notation (JSON)", RFC 4627, July 2006. JavaScript Object Notation (JSON)", RFC 4627, July 2006.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, October 2006. Encodings", RFC 4648, October 2006.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008. (TLS) Protocol Version 1.2", RFC 5246, August 2008.
skipping to change at page 25, line 27 skipping to change at page 30, line 14
Infrastructure Certificate and Certificate Revocation List Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008. (CRL) Profile", RFC 5280, May 2008.
[W3C.CR-xmlenc-core1-20120313] [W3C.CR-xmlenc-core1-20120313]
Eastlake, D., Reagle, J., Roessler, T., and F. Hirsch, Eastlake, D., Reagle, J., Roessler, T., and F. Hirsch,
"XML Encryption Syntax and Processing Version 1.1", World "XML Encryption Syntax and Processing Version 1.1", World
Wide Web Consortium CR CR-xmlenc-core1-20120313, Wide Web Consortium CR CR-xmlenc-core1-20120313,
March 2012, March 2012,
<http://www.w3.org/TR/2012/CR-xmlenc-core1-20120313>. <http://www.w3.org/TR/2012/CR-xmlenc-core1-20120313>.
9.2. Informative References 11.2. Informative References
[I-D.mcgrew-aead-aes-cbc-hmac-sha2]
McGrew, D. and K. Paterson, "Authenticated Encryption with
AES-CBC and HMAC-SHA",
draft-mcgrew-aead-aes-cbc-hmac-sha2-01 (work in progress),
October 2012.
[I-D.rescorla-jsms] [I-D.rescorla-jsms]
Rescorla, E. and J. Hildebrand, "JavaScript Message Rescorla, E. and J. Hildebrand, "JavaScript Message
Security Format", draft-rescorla-jsms-00 (work in Security Format", draft-rescorla-jsms-00 (work in
progress), March 2011. progress), March 2011.
[JSE] Bradley, J. and N. Sakimura (editor), "JSON Simple [JSE] Bradley, J. and N. Sakimura (editor), "JSON Simple
Encryption", September 2010. Encryption", September 2010.
[JWE-JS] Jones, M., "JSON Web Encryption JSON Serialization [JWT] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
(JWE-JS)", draft-jones-jose-jwe-json-serialization (work (JWT)", draft-ietf-oauth-json-web-token (work in
in progress), December 2012. progress), April 2013.
[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 [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122, Unique IDentifier (UUID) URN Namespace", RFC 4122,
July 2005. July 2005.
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70, [RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
RFC 5652, September 2009. RFC 5652, September 2009.
Appendix A. JWE Examples Appendix A. JWE Examples
This section provides examples of JWE computations. This section provides examples of JWE computations.
A.1. Example JWE using RSAES OAEP and AES GCM A.1. Example JWE using RSAES OAEP and AES GCM
This example encrypts the plaintext "Live long and prosper." to the This example encrypts the plaintext "The true sign of intelligence is
recipient using RSAES OAEP and AES GCM. The AES GCM algorithm has an not knowledge but imagination." to the recipient using RSAES OAEP and
integrated integrity check. The representation of this plaintext is: AES GCM. The representation of this plaintext is:
[76, 105, 118, 101, 32, 108, 111, 110, 103, 32, 97, 110, 100, 32, [84, 104, 101, 32, 116, 114, 117, 101, 32, 115, 105, 103, 110, 32,
112, 114, 111, 115, 112, 101, 114, 46] 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]
A.1.1. JWE Header A.1.1. JWE Header
The following example JWE Header declares that: The following example JWE Header declares that:
o the Content Master Key is encrypted to the recipient using the o the Content Encryption Key is encrypted to the recipient using the
RSAES OAEP algorithm to produce the JWE Encrypted Key and RSAES OAEP algorithm to produce the JWE Encrypted Key and
o the Plaintext is encrypted using the AES GCM algorithm with a 256 o the Plaintext is encrypted using the AES GCM algorithm with a 256
bit key to produce the Ciphertext. bit key to produce the Ciphertext.
{"alg":"RSA-OAEP","enc":"A256GCM"} {"alg":"RSA-OAEP","enc":"A256GCM"}
A.1.2. Encoded JWE Header A.1.2. Encoded JWE Header
Base64url encoding the bytes of the UTF-8 representation of the JWE Base64url encoding the octets of the UTF-8 representation of the JWE
Header yields this Encoded JWE Header value: Header yields this Encoded JWE Header value:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ
A.1.3. Content Master Key (CMK) A.1.3. Content Encryption Key (CEK)
Generate a 256 bit random Content Master Key (CMK). In this example, Generate a 256 bit random Content Encryption Key (CEK). In this
the value is: example, the value is:
[177, 161, 244, 128, 84, 143, 225, 115, 63, 180, 3, 255, 107, 154, [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, 212, 246, 138, 7, 110, 91, 112, 46, 34, 105, 47, 130, 203, 46, 122,
234, 64, 252] 234, 64, 252]
A.1.4. Key Encryption A.1.4. Key Encryption
Encrypt the CMK with the recipient's public key using the RSAES OAEP 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 algorithm to produce the JWE Encrypted Key. In this example, the RSA
key parameters are: key parameters are:
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| Parameter | Value | | Parameter | Value |
| Name | | | Name | |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| Modulus | [161, 168, 84, 34, 133, 176, 208, 173, 46, 176, 163, | | Modulus | [161, 168, 84, 34, 133, 176, 208, 173, 46, 176, 163, |
| | 110, 57, 30, 135, 227, 9, 31, 226, 128, 84, 92, 116, | | | 110, 57, 30, 135, 227, 9, 31, 226, 128, 84, 92, 116, |
| | 241, 70, 248, 27, 227, 193, 62, 5, 91, 241, 145, 224, | | | 241, 70, 248, 27, 227, 193, 62, 5, 91, 241, 145, 224, |
skipping to change at page 28, line 31 skipping to change at page 33, line 31
| | 38, 249, 208, 17, 197, 49, 45, 19, 232, 157, 251, | | | 38, 249, 208, 17, 197, 49, 45, 19, 232, 157, 251, |
| | 131, 137, 175, 72, 126, 43, 229, 69, 179, 117, 82, | | | 131, 137, 175, 72, 126, 43, 229, 69, 179, 117, 82, |
| | 157, 213, 83, 35, 57, 210, 197, 252, 171, 143, 194, | | | 157, 213, 83, 35, 57, 210, 197, 252, 171, 143, 194, |
| | 11, 47, 163, 6, 253, 75, 252, 96, 11, 187, 84, 130, | | | 11, 47, 163, 6, 253, 75, 252, 96, 11, 187, 84, 130, |
| | 210, 7, 121, 78, 91, 79, 57, 251, 138, 132, 220, 60, | | | 210, 7, 121, 78, 91, 79, 57, 251, 138, 132, 220, 60, |
| | 224, 173, 56, 224, 201] | | | 224, 173, 56, 224, 201] |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
The resulting JWE Encrypted Key value is: The resulting JWE Encrypted Key value is:
[51, 101, 241, 165, 179, 145, 41, 236, 202, 75, 60, 208, 47, 255, [2, 151, 206, 44, 38, 131, 110, 171, 63, 37, 115, 216, 203, 98, 61,
121, 248, 104, 226, 185, 212, 65, 78, 169, 255, 162, 100, 188, 207, 223, 187, 255, 198, 106, 243, 143, 226, 44, 179, 89, 134, 232, 208,
220, 96, 161, 22, 251, 47, 66, 112, 229, 75, 4, 111, 25, 173, 200, 7, 153, 226, 85, 136, 206, 163, 218, 93, 12, 30, 247, 236, 120, 135,
121, 246, 79, 189, 102, 173, 146, 228, 142, 14, 12, 167, 200, 27, 71, 87, 37, 54, 4, 138, 6, 86, 239, 104, 134, 249, 36, 90, 36, 106,
133, 138, 37, 180, 249, 4, 56, 123, 192, 162, 156, 246, 231, 235, 228, 50, 246, 141, 134, 83, 60, 15, 83, 1, 220, 42, 220, 85, 8, 87,
217, 240, 45, 158, 213, 195, 154, 2, 142, 86, 61, 198, 210, 34, 225, 42, 7, 248, 247, 157, 127, 167, 165, 28, 133, 69, 139, 98, 134, 12,
92, 7, 128, 227, 4, 227, 55, 183, 69, 0, 59, 162, 71, 145, 98, 238, 75, 41, 96, 203, 80, 1, 19, 12, 72, 23, 18, 238, 155, 37, 199, 167,
0, 70, 40, 123, 159, 37, 115, 18, 16, 157, 236, 138, 117, 166, 18, 229, 135, 80, 159, 135, 113, 129, 43, 43, 51, 181, 83, 4, 133, 159,
45, 181, 125, 112, 170, 168, 82, 129, 80, 166, 242, 150, 97, 17, 217, 230, 104, 89, 38, 224, 246, 21, 10, 194, 108, 190, 174, 130, 183,
109, 251, 51, 35, 39, 236, 107, 95, 43, 154, 4, 227, 206, 187, 75, 119, 224, 216, 34, 79, 58, 205, 23, 212, 49, 238, 197, 146, 168, 32,
13, 51, 231, 115, 79, 67, 72, 145, 54, 225, 164, 60, 195, 120, 188, 98, 42, 113, 183, 138, 225, 113, 14, 229, 173, 33, 229, 48, 46, 36,
69, 113, 3, 182, 21, 189, 79, 82, 122, 46, 196, 199, 254, 252, 7, 230, 202, 117, 243, 180, 116, 172, 31, 53, 36, 155, 166, 238, 108,
119, 5, 32, 144, 143, 173, 11, 99, 205, 120, 106, 231, 51, 231, 77, 22, 186, 81, 23, 5, 118, 21, 52, 216, 162, 161, 120, 204, 142, 58,
73, 252, 197, 221, 142, 254, 151, 7, 6, 203, 65, 108, 117, 121, 15, 55, 223, 191, 132, 194, 51, 158, 81, 41, 126, 212, 87, 133, 39, 4,
95, 43, 111, 13, 94, 242, 226, 150, 94, 121, 72, 144, 251, 69, 93, 38, 230, 125, 28, 111, 2, 240, 33, 193, 213, 100, 89, 252, 158, 60,
137, 178, 13, 216, 8, 227, 125, 110, 180, 157, 250, 207, 184, 232, 62, 87, 170, 118, 17, 120, 163, 183, 193, 228, 157, 112, 22, 165, 23,
222, 164, 193, 70, 232, 16, 65, 109, 29, 251, 164, 119, 50, 205, 236, 6, 214, 237, 184, 98, 127, 3, 101, 222, 232, 1, 33, 174, 92, 194, 59]
109, 245, 234, 78, 1]
A.1.5. Encoded JWE Encrypted Key A.1.5. Encoded JWE Encrypted Key
Base64url encode the JWE Encrypted Key to produce the Encoded JWE Base64url encode the JWE Encrypted Key to produce the Encoded JWE
Encrypted Key. This result (with line breaks for display purposes Encrypted Key. This result (with line breaks for display purposes
only) is: only) is:
M2XxpbORKezKSzzQL_95-GjiudRBTqn_omS8z9xgoRb7L0Jw5UsEbxmtyHn2T71m ApfOLCaDbqs_JXPYy2I937v_xmrzj-Iss1mG6NAHmeJViM6j2l0MHvfseIdHVyU2
rZLkjg4Mp8gbhYoltPkEOHvAopz25-vZ8C2e1cOaAo5WPcbSIuFcB4DjBOM3t0UA BIoGVu9ohvkkWiRq5DL2jYZTPA9TAdwq3FUIVyoH-Pedf6elHIVFi2KGDEspYMtQ
O6JHkWLuAEYoe58lcxIQneyKdaYSLbV9cKqoUoFQpvKWYRHZbfszIyfsa18rmgTj ARMMSBcS7pslx6flh1Cfh3GBKysztVMEhZ_maFkm4PYVCsJsvq6Ct3fg2CJPOs0X
zrtLDTPnc09DSJE24aQ8w3i8RXEDthW9T1J6LsTH_vwHdwUgkI-tC2PNeGrnM-dN 1DHuxZKoIGIqcbeK4XEO5a0h5TAuJObKdfO0dKwfNSSbpu5sFrpRFwV2FTTYoqF4
SfzF3Y7-lwcGy0FsdXkPXytvDV7y4pZeeUiQ-0VdibIN2AjjfW60nfrPuOjepMFG zI46N9-_hMIznlEpftRXhScEJuZ9HG8C8CHB1WRZ_J48PleqdhF4o7fB5J1wFqUX
6BBBbR37pHcyzext9epOAQ BtbtuGJ_A2Xe6AEhrlzCOw
A.1.6. Initialization Vector A.1.6. Initialization Vector
Generate a random 96 bit JWE Initialization Vector. In this example, Generate a random 96 bit JWE Initialization Vector. In this example,
the value is: the value is:
[227, 197, 117, 252, 2, 219, 233, 68, 180, 225, 77, 219] [227, 197, 117, 252, 2, 219, 233, 68, 180, 225, 77, 219]
Base64url encoding this value yields the Encoded JWE Initialization Base64url encoding this value yields the Encoded JWE Initialization
Vector value: Vector value:
48V1_ALb6US04U3b 48V1_ALb6US04U3b
A.1.7. "Additional Authenticated Data" Parameter A.1.7. Additional Authenticated Data Parameter
Concatenate the Encoded JWE Header value, a period character ('.'), Concatenate the Encoded JWE Header value, a period ('.') character,
the Encoded JWE Encrypted Key, a second period character ('.'), and and the Encoded JWE Encrypted Key to create the Additional
the Encoded JWE Initialization Vector to create the "additional Authenticated Data parameter. This result (with line breaks for
authenticated data" parameter for the AES GCM algorithm. This result display purposes only) is:
(with line breaks for display purposes only) is:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ. eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ.
M2XxpbORKezKSzzQL_95-GjiudRBTqn_omS8z9xgoRb7L0Jw5UsEbxmtyHn2T71m ApfOLCaDbqs_JXPYy2I937v_xmrzj-Iss1mG6NAHmeJViM6j2l0MHvfseIdHVyU2
rZLkjg4Mp8gbhYoltPkEOHvAopz25-vZ8C2e1cOaAo5WPcbSIuFcB4DjBOM3t0UA BIoGVu9ohvkkWiRq5DL2jYZTPA9TAdwq3FUIVyoH-Pedf6elHIVFi2KGDEspYMtQ
O6JHkWLuAEYoe58lcxIQneyKdaYSLbV9cKqoUoFQpvKWYRHZbfszIyfsa18rmgTj ARMMSBcS7pslx6flh1Cfh3GBKysztVMEhZ_maFkm4PYVCsJsvq6Ct3fg2CJPOs0X
zrtLDTPnc09DSJE24aQ8w3i8RXEDthW9T1J6LsTH_vwHdwUgkI-tC2PNeGrnM-dN 1DHuxZKoIGIqcbeK4XEO5a0h5TAuJObKdfO0dKwfNSSbpu5sFrpRFwV2FTTYoqF4
SfzF3Y7-lwcGy0FsdXkPXytvDV7y4pZeeUiQ-0VdibIN2AjjfW60nfrPuOjepMFG zI46N9-_hMIznlEpftRXhScEJuZ9HG8C8CHB1WRZ_J48PleqdhF4o7fB5J1wFqUX
6BBBbR37pHcyzext9epOAQ. BtbtuGJ_A2Xe6AEhrlzCOw
48V1_ALb6US04U3b
The representation of this value is: The representation of this value is:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 83, 85, 48, 69, [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, 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, 54, 73, 107, 69, 121, 78, 84, 90, 72, 81, 48, 48, 105, 102, 81, 46,
77, 50, 88, 120, 112, 98, 79, 82, 75, 101, 122, 75, 83, 122, 122, 81, 65, 112, 102, 79, 76, 67, 97, 68, 98, 113, 115, 95, 74, 88, 80, 89,
76, 95, 57, 53, 45, 71, 106, 105, 117, 100, 82, 66, 84, 113, 110, 95, 121, 50, 73, 57, 51, 55, 118, 95, 120, 109, 114, 122, 106, 45, 73,
111, 109, 83, 56, 122, 57, 120, 103, 111, 82, 98, 55, 76, 48, 74, 115, 115, 49, 109, 71, 54, 78, 65, 72, 109, 101, 74, 86, 105, 77, 54,
119, 53, 85, 115, 69, 98, 120, 109, 116, 121, 72, 110, 50, 84, 55, 106, 50, 108, 48, 77, 72, 118, 102, 115, 101, 73, 100, 72, 86, 121,
49, 109, 114, 90, 76, 107, 106, 103, 52, 77, 112, 56, 103, 98, 104, 85, 50, 66, 73, 111, 71, 86, 117, 57, 111, 104, 118, 107, 107, 87,
89, 111, 108, 116, 80, 107, 69, 79, 72, 118, 65, 111, 112, 122, 50, 105, 82, 113, 53, 68, 76, 50, 106, 89, 90, 84, 80, 65, 57, 84, 65,
53, 45, 118, 90, 56, 67, 50, 101, 49, 99, 79, 97, 65, 111, 53, 87, 100, 119, 113, 51, 70, 85, 73, 86, 121, 111, 72, 45, 80, 101, 100,
80, 99, 98, 83, 73, 117, 70, 99, 66, 52, 68, 106, 66, 79, 77, 51, 102, 54, 101, 108, 72, 73, 86, 70, 105, 50, 75, 71, 68, 69, 115, 112,
116, 48, 85, 65, 79, 54, 74, 72, 107, 87, 76, 117, 65, 69, 89, 111, 89, 77, 116, 81, 65, 82, 77, 77, 83, 66, 99, 83, 55, 112, 115, 108,
101, 53, 56, 108, 99, 120, 73, 81, 110, 101, 121, 75, 100, 97, 89, 120, 54, 102, 108, 104, 49, 67, 102, 104, 51, 71, 66, 75, 121, 115,
83, 76, 98, 86, 57, 99, 75, 113, 111, 85, 111, 70, 81, 112, 118, 75, 122, 116, 86, 77, 69, 104, 90, 95, 109, 97, 70, 107, 109, 52, 80, 89,
87, 89, 82, 72, 90, 98, 102, 115, 122, 73, 121, 102, 115, 97, 49, 56, 86, 67, 115, 74, 115, 118, 113, 54, 67, 116, 51, 102, 103, 50, 67,
114, 109, 103, 84, 106, 122, 114, 116, 76, 68, 84, 80, 110, 99, 48, 74, 80, 79, 115, 48, 88, 49, 68, 72, 117, 120, 90, 75, 111, 73, 71,
57, 68, 83, 74, 69, 50, 52, 97, 81, 56, 119, 51, 105, 56, 82, 88, 69, 73, 113, 99, 98, 101, 75, 52, 88, 69, 79, 53, 97, 48, 104, 53, 84,
68, 116, 104, 87, 57, 84, 49, 74, 54, 76, 115, 84, 72, 95, 118, 119, 65, 117, 74, 79, 98, 75, 100, 102, 79, 48, 100, 75, 119, 102, 78, 83,
72, 100, 119, 85, 103, 107, 73, 45, 116, 67, 50, 80, 78, 101, 71, 83, 98, 112, 117, 53, 115, 70, 114, 112, 82, 70, 119, 86, 50, 70, 84,
114, 110, 77, 45, 100, 78, 83, 102, 122, 70, 51, 89, 55, 45, 108, 84, 89, 111, 113, 70, 52, 122, 73, 52, 54, 78, 57, 45, 95, 104, 77,
119, 99, 71, 121, 48, 70, 115, 100, 88, 107, 80, 88, 121, 116, 118, 73, 122, 110, 108, 69, 112, 102, 116, 82, 88, 104, 83, 99, 69, 74,
68, 86, 55, 121, 52, 112, 90, 101, 101, 85, 105, 81, 45, 48, 86, 100, 117, 90, 57, 72, 71, 56, 67, 56, 67, 72, 66, 49, 87, 82, 90, 95, 74,
105, 98, 73, 78, 50, 65, 106, 106, 102, 87, 54, 48, 110, 102, 114, 52, 56, 80, 108, 101, 113, 100, 104, 70, 52, 111, 55, 102, 66, 53,
80, 117, 79, 106, 101, 112, 77, 70, 71, 54, 66, 66, 66, 98, 82, 51, 74, 49, 119, 70, 113, 85, 88, 66, 116, 98, 116, 117, 71, 74, 95, 65,
55, 112, 72, 99, 121, 122, 101, 120, 116, 57, 101, 112, 79, 65, 81, 50, 88, 101, 54, 65, 69, 104, 114, 108, 122, 67, 79, 119]
46, 52, 56, 86, 49, 95, 65, 76, 98, 54, 85, 83, 48, 52, 85, 51, 98]
A.1.8. Plaintext Encryption A.1.8. Plaintext Encryption
Encrypt the Plaintext with AES GCM using the CMK as the encryption Encrypt the Plaintext with AES GCM using the CEK as the encryption
key, the JWE Initialization Vector, and the "additional authenticated key, the JWE Initialization Vector, and the Additional Authenticated
data" value above, requesting a 128 bit "authentication tag" output. Data value above, requesting a 128 bit Authentication Tag output.
The resulting Ciphertext is: The resulting Ciphertext is:
[253, 237, 181, 180, 97, 161, 105, 207, 233, 120, 65, 100, 45, 122, [229, 236, 166, 241, 53, 191, 115, 196, 174, 43, 73, 109, 39, 122,
246, 116, 195, 212, 102, 37, 36, 175] 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: The resulting Authentication Tag value is:
[237, 94, 89, 14, 74, 52, 191, 249, 159, 216, 240, 28, 224, 147, 34, [130, 17, 32, 198, 120, 167, 144, 113, 0, 50, 158, 49, 102, 208, 118,
82] 152]
A.1.9. Encoded JWE Ciphertext A.1.9. Encoded JWE Ciphertext
Base64url encode the resulting Ciphertext to create the Encoded JWE Base64url encode the Ciphertext to create the Encoded JWE Ciphertext.
Ciphertext. This result is: This result (with line breaks for display purposes only) is:
_e21tGGhac_peEFkLXr2dMPUZiUkrw 5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji
SdiwkIr3ajwQzaBtQD_A
A.1.10. Encoded JWE Integrity Value A.1.10. Encoded JWE Authentication Tag
Base64url encode the resulting "authentication tag" to create the Base64url encode the Authentication Tag to create the Encoded JWE
Encoded JWE Integrity Value. This result is: Authentication Tag. This result is:
7V5ZDko0v_mf2PAc4JMiUg ghEgxninkHEAMp4xZtB2mA
A.1.11. Complete Representation A.1.11. Complete Representation
Assemble the final representation: The Compact Serialization of this Assemble the final representation: The Compact Serialization of this
result is the concatenation of the Encoded JWE Header, the Encoded result is the concatenation of the Encoded JWE Header, the Encoded
JWE Encrypted Key, the Encoded JWE Initialization Vector, the Encoded JWE Encrypted Key, the Encoded JWE Initialization Vector, the Encoded
JWE Ciphertext, and the Encoded JWE Integrity Value in that order, JWE Ciphertext, and the Encoded JWE Authentication Tag in that order,
with the five strings being separated by four period ('.') with the five strings being separated by four period ('.')
characters. characters.
The final result in this example (with line breaks for display The final result in this example (with line breaks for display
purposes only) is: purposes only) is:
eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ. eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ.
M2XxpbORKezKSzzQL_95-GjiudRBTqn_omS8z9xgoRb7L0Jw5UsEbxmtyHn2T71m ApfOLCaDbqs_JXPYy2I937v_xmrzj-Iss1mG6NAHmeJViM6j2l0MHvfseIdHVyU2
rZLkjg4Mp8gbhYoltPkEOHvAopz25-vZ8C2e1cOaAo5WPcbSIuFcB4DjBOM3t0UA BIoGVu9ohvkkWiRq5DL2jYZTPA9TAdwq3FUIVyoH-Pedf6elHIVFi2KGDEspYMtQ
O6JHkWLuAEYoe58lcxIQneyKdaYSLbV9cKqoUoFQpvKWYRHZbfszIyfsa18rmgTj ARMMSBcS7pslx6flh1Cfh3GBKysztVMEhZ_maFkm4PYVCsJsvq6Ct3fg2CJPOs0X
zrtLDTPnc09DSJE24aQ8w3i8RXEDthW9T1J6LsTH_vwHdwUgkI-tC2PNeGrnM-dN 1DHuxZKoIGIqcbeK4XEO5a0h5TAuJObKdfO0dKwfNSSbpu5sFrpRFwV2FTTYoqF4
SfzF3Y7-lwcGy0FsdXkPXytvDV7y4pZeeUiQ-0VdibIN2AjjfW60nfrPuOjepMFG zI46N9-_hMIznlEpftRXhScEJuZ9HG8C8CHB1WRZ_J48PleqdhF4o7fB5J1wFqUX
6BBBbR37pHcyzext9epOAQ. BtbtuGJ_A2Xe6AEhrlzCOw.
48V1_ALb6US04U3b. 48V1_ALb6US04U3b.
_e21tGGhac_peEFkLXr2dMPUZiUkrw. 5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji
7V5ZDko0v_mf2PAc4JMiUg SdiwkIr3ajwQzaBtQD_A.
ghEgxninkHEAMp4xZtB2mA
A.1.12. Validation A.1.12. Validation
This example illustrates the process of creating a JWE with an This example illustrates the process of creating a JWE with RSA OAEP
Authenticated Encryption algorithm. These results can be used to and AES GCM. These results can be used to validate JWE decryption
validate JWE decryption implementations for these algorithms. Note implementations for these algorithms. Note that since the RSAES OAEP
that since the RSAES OAEP computation includes random values, the computation includes random values, the encryption results above will
encryption results above will not be completely reproducible. not be completely reproducible. However, since the AES GCM
However, since the AES GCM computation is deterministic, the JWE computation is deterministic, the JWE Encrypted Ciphertext values
Encrypted Ciphertext values will be the same for all encryptions will be the same for all encryptions performed using these inputs.
performed using these inputs.
A.2. Example JWE using RSAES-PKCS1-V1_5 and AES CBC A.2. Example JWE using RSAES-PKCS1-V1_5 and AES_128_CBC_HMAC_SHA_256
This example encrypts the plaintext "No matter where you go, there This example encrypts the plaintext "Live long and prosper." to the
you are." to the recipient using RSAES-PKCS1-V1_5 and AES CBC. AES recipient using RSAES-PKCS1-V1_5 and AES_128_CBC_HMAC_SHA_256. The
CBC does not have an integrated integrity check, so a separate
integrity check calculation is performed using HMAC SHA-256, with
separate encryption and integrity keys being derived from a master
key using the Concat KDF with the SHA-256 digest function. The
representation of this plaintext is: representation of this plaintext is:
[78, 111, 32, 109, 97, 116, 116, 101, 114, 32, 119, 104, 101, 114, [76, 105, 118, 101, 32, 108, 111, 110, 103, 32, 97, 110, 100, 32,
101, 32, 121, 111, 117, 32, 103, 111, 44, 32, 116, 104, 101, 114, 112, 114, 111, 115, 112, 101, 114, 46]
101, 32, 121, 111, 117, 32, 97, 114, 101, 46]
A.2.1. JWE Header A.2.1. JWE Header
The following example JWE Header (with line breaks for display The following example JWE Header (with line breaks for display
purposes only) declares that: purposes only) declares that:
o the Content Master Key is encrypted to the recipient using the o the Content Encryption Key is encrypted to the recipient using the
RSAES-PKCS1-V1_5 algorithm to produce the JWE Encrypted Key and RSAES-PKCS1-V1_5 algorithm to produce the JWE Encrypted Key and
o the Plaintext is encrypted using the AES CBC algorithm with a 128 o the Plaintext is encrypted using the AES_128_CBC_HMAC_SHA_256
bit key to produce the Ciphertext, with the integrity of the algorithm to produce the Ciphertext.
Ciphertext and the parameters used to create it being secured with
the HMAC SHA-256 algorithm.
{"alg":"RSA1_5","enc":"A128CBC+HS256"} {"alg":"RSA1_5","enc":"A128CBC-HS256"}
A.2.2. Encoded JWE Header A.2.2. Encoded JWE Header
Base64url encoding the bytes of the UTF-8 representation of the JWE Base64url encoding the octets of the UTF-8 representation of the JWE
Header yields this Encoded JWE Header value: Header yields this Encoded JWE Header value:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDK0hTMjU2In0 eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0
A.2.3. Content Master Key (CMK) A.2.3. Content Encryption Key (CEK)
Generate a 256 bit random Content Master Key (CMK). In this example, Generate a 256 bit random Content Encryption Key (CEK). In this
the key value is: example, the key value is:
[4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106, [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, 206, 107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156,
44, 207] 44, 207]
A.2.4. Key Encryption A.2.4. Key Encryption
Encrypt the CMK with the recipient's public key using the RSAES- Encrypt the CEK with the recipient's public key using the RSAES-
PKCS1-V1_5 algorithm to produce the JWE Encrypted Key. In this PKCS1-V1_5 algorithm to produce the JWE Encrypted Key. In this
example, the RSA key parameters are: example, the RSA key parameters are:
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| Parameter | Value | | Parameter | Value |
| Name | | | Name | |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| Modulus | [177, 119, 33, 13, 164, 30, 108, 121, 207, 136, 107, | | Modulus | [177, 119, 33, 13, 164, 30, 108, 121, 207, 136, 107, |
| | 242, 12, 224, 19, 226, 198, 134, 17, 71, 173, 75, 42, | | | 242, 12, 224, 19, 226, 198, 134, 17, 71, 173, 75, 42, |
| | 61, 48, 162, 206, 161, 97, 108, 185, 234, 226, 219, | | | 61, 48, 162, 206, 161, 97, 108, 185, 234, 226, 219, |
skipping to change at page 34, line 31 skipping to change at page 39, line 31
| | 46, 196, 90, 173, 38, 245, 219, 186, 222, 27, 240, | | | 46, 196, 90, 173, 38, 245, 219, 186, 222, 27, 240, |
| | 212, 194, 15, 66, 135, 226, 178, 190, 52, 245, 74, | | | 212, 194, 15, 66, 135, 226, 178, 190, 52, 245, 74, |
| | 65, 224, 81, 100, 85, 25, 204, 165, 203, 187, 175, | | | 65, 224, 81, 100, 85, 25, 204, 165, 203, 187, 175, |
| | 84, 100, 82, 15, 11, 23, 202, 151, 107, 54, 41, 207, | | | 84, 100, 82, 15, 11, 23, 202, 151, 107, 54, 41, 207, |
| | 3, 136, 229, 134, 131, 93, 139, 50, 182, 204, 93, | | | 3, 136, 229, 134, 131, 93, 139, 50, 182, 204, 93, |
| | 130, 89] | | | 130, 89] |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
The resulting JWE Encrypted Key value is: The resulting JWE Encrypted Key value is:
[102, 105, 229, 169, 104, 35, 95, 42, 176, 142, 190, 220, 92, 124, [156, 150, 191, 184, 77, 131, 211, 9, 74, 207, 227, 156, 193, 38,
172, 240, 94, 253, 106, 114, 20, 35, 162, 118, 81, 103, 64, 201, 20, 202, 23, 56, 247, 211, 108, 88, 72, 143, 145, 44, 19, 58, 133, 181,
4, 112, 96, 84, 248, 163, 199, 177, 227, 204, 247, 93, 63, 70, 132, 70, 152, 254, 26, 198, 210, 80, 60, 15, 82, 210, 154, 55, 179, 115,
195, 26, 237, 72, 91, 141, 3, 159, 71, 111, 113, 213, 68, 142, 146, 76, 146, 99, 166, 146, 70, 176, 157, 252, 15, 54, 58, 92, 210, 103,
92, 60, 243, 72, 111, 53, 156, 51, 16, 226, 215, 125, 68, 141, 232, 55, 207, 191, 92, 185, 5, 164, 64, 241, 80, 163, 233, 131, 198, 106,
62, 111, 197, 98, 91, 150, 23, 230, 132, 93, 97, 216, 145, 226, 3, 32, 207, 199, 113, 5, 200, 94, 105, 53, 32, 221, 155, 233, 108, 96,
18, 12, 48, 119, 153, 185, 8, 156, 195, 84, 21, 63, 143, 43, 144, 151, 197, 152, 195, 96, 67, 81, 90, 38, 121, 51, 208, 98, 47, 45, 61,
174, 101, 25, 199, 7, 106, 212, 43, 151, 225, 62, 225, 122, 92, 90, 4, 129, 121, 152, 122, 124, 229, 2, 250, 92, 64, 245, 36, 70, 76, 58,
139, 45, 144, 134, 229, 15, 235, 38, 110, 132, 189, 236, 126, 92, 31, 181, 185, 61, 101, 168, 240, 220, 12, 62, 253, 169, 107, 107, 9,
183, 13, 64, 2, 77, 107, 95, 186, 8, 133, 53, 217, 104, 247, 152, 241, 9, 152, 217, 159, 179, 30, 95, 112, 29, 143, 124, 7, 21, 181,
241, 49, 199, 15, 111, 110, 123, 16, 13, 78, 193, 224, 23, 230, 133, 13, 45, 253, 137, 142, 95, 30, 127, 26, 237, 34, 183, 89, 200, 44,
220, 162, 126, 82, 192, 236, 7, 185, 100, 106, 21, 70, 93, 192, 255, 165, 203, 71, 102, 39, 127, 217, 159, 46, 17, 28, 11, 146, 222, 110,
252, 139, 61, 124, 81, 140, 113, 97, 164, 231, 131, 167, 246, 157, 149, 178, 16, 117, 186, 91, 52, 56, 136, 127, 82, 33, 194, 46, 164,
199, 195, 114, 122, 49, 121, 115, 63, 114, 12, 165, 11, 186, 3, 108, 245, 117, 136, 160, 179, 152, 151, 15, 172, 48, 73, 228, 87, 63, 40,
12, 199, 101, 29, 226, 80, 56, 193, 149, 45, 134, 146, 102, 221, 202, 192, 92, 92, 24, 167, 105, 47, 255, 193, 251, 77, 203, 6, 134, 129,
63, 166, 150, 53, 42, 133, 3, 83, 199, 14, 15, 181, 209, 199, 174, 248, 191, 53, 43, 49, 219, 130, 241, 180, 174, 159, 34, 71, 163, 70,
76, 75, 106, 254, 243, 196, 227, 225, 173, 122, 254, 13, 224, 174, 4, 83, 1, 152, 39, 241, 191, 68, 224, 240, 43, 113, 165, 68, 98, 130]
185, 217, 99, 225]
A.2.5. Encoded JWE Encrypted Key A.2.5. Encoded JWE Encrypted Key
Base64url encode the JWE Encrypted Key to produce the Encoded JWE Base64url encode the JWE Encrypted Key to produce the Encoded JWE
Encrypted Key. This result (with line breaks for display purposes Encrypted Key. This result (with line breaks for display purposes
only) is: only) is:
ZmnlqWgjXyqwjr7cXHys8F79anIUI6J2UWdAyRQEcGBU-KPHsePM910_RoTDGu1I nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMkmOm
W40Dn0dvcdVEjpJcPPNIbzWcMxDi131Ejeg-b8ViW5YX5oRdYdiR4gMSDDB3mbkI kkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZjDYENR
nMNUFT-PK5CuZRnHB2rUK5fhPuF6XFqLLZCG5Q_rJm6Evex-XLcNQAJNa1-6CIU1 WiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfEJmNmfsx5f
2Wj3mPExxw9vbnsQDU7B4BfmhdyiflLA7Ae5ZGoVRl3A__yLPXxRjHFhpOeDp_ad cB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWyEHW6WzQ4iH9S
x8NyejF5cz9yDKULugNsDMdlHeJQOMGVLYaSZt3KP6aWNSqFA1PHDg-10ceuTEtq IcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_NSsx24LxtK6fIkej
_vPE4-Gtev4N4K4Eudlj4Q RlMBmCfxv0Tg8CtxpURigg
A.2.6. Key Derivation
Use the Concat key derivation function to derive Content Encryption
Key (CEK) and Content Integrity Key (CIK) values from the CMK. The
details of this derivation are shown in Appendix A.4. The resulting
CEK value is:
[203, 165, 180, 113, 62, 195, 22, 98, 91, 153, 210, 38, 112, 35, 230,
236]
The resulting CIK value is:
[218, 24, 160, 17, 160, 50, 235, 35, 216, 209, 100, 174, 155, 163,
10, 117, 180, 111, 172, 200, 127, 201, 206, 173, 40, 45, 58, 170, 35,
93, 9, 60]
A.2.7. Initialization Vector A.2.6. Initialization Vector
Generate a random 128 bit JWE Initialization Vector. In this Generate a random 128 bit JWE Initialization Vector. In this
example, the value is: example, the value is:
[3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104, [3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104,
101] 101]
Base64url encoding this value yields the Encoded JWE Initialization Base64url encoding this value yields the Encoded JWE Initialization
Vector value: Vector value:
AxY8DCtDaGlsbGljb3RoZQ AxY8DCtDaGlsbGljb3RoZQ
A.2.8. Plaintext Encryption A.2.7. Additional Authenticated Data Parameter
Encrypt the Plaintext with AES CBC using the CEK and the JWE
Initialization Vector to produce the Ciphertext. The resulting
Ciphertext is:
[71, 27, 35, 131, 163, 200, 19, 23, 38, 25, 33, 123, 46, 116, 132, Concatenate the Encoded JWE Header value, a period ('.') character,
144, 58, 150, 32, 167, 192, 195, 92, 25, 207, 101, 233, 105, 181, and the Encoded JWE Encrypted Key to create the Additional
121, 63, 4, 44, 162, 82, 176, 17, 171, 150, 97, 147, 68, 245, 13, 97, Authenticated Data parameter. This result (with line breaks for
100, 145, 25] display purposes only) is:
A.2.9. Encoded JWE Ciphertext eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.
nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMkmOm
kkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZjDYENR
WiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfEJmNmfsx5f
cB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWyEHW6WzQ4iH9S
IcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_NSsx24LxtK6fIkej
RlMBmCfxv0Tg8CtxpURigg
Base64url encode the resulting Ciphertext to create the Encoded JWE The representation of this value is:
Ciphertext. This result is:
Rxsjg6PIExcmGSF7LnSEkDqWIKfAw1wZz2XpabV5PwQsolKwEauWYZNE9Q1hZJEZ [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]
A.2.10. Secured Input Value A.2.8. Plaintext Encryption
Concatenate the Encoded JWE Header value, a period character ('.'), Encrypt the Plaintext with AES_128_CBC_HMAC_SHA_256 using the CEK as
the Encoded JWE Encrypted Key, a second period character, the Encoded the encryption key, the JWE Initialization Vector, and the Additional
JWE Initialization Vector, a third period ('.') character, and the Authenticated Data value above. The steps for doing this using the
Encoded JWE Ciphertext to create the value to integrity protect. values from Appendix A.3 are detailed in Appendix B. The resulting
This result (with line breaks for display purposes only) is: Ciphertext is:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDK0hTMjU2In0. [40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6,
ZmnlqWgjXyqwjr7cXHys8F79anIUI6J2UWdAyRQEcGBU-KPHsePM910_RoTDGu1I 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143,
W40Dn0dvcdVEjpJcPPNIbzWcMxDi131Ejeg-b8ViW5YX5oRdYdiR4gMSDDB3mbkI 112, 56, 102]
nMNUFT-PK5CuZRnHB2rUK5fhPuF6XFqLLZCG5Q_rJm6Evex-XLcNQAJNa1-6CIU1
2Wj3mPExxw9vbnsQDU7B4BfmhdyiflLA7Ae5ZGoVRl3A__yLPXxRjHFhpOeDp_ad
x8NyejF5cz9yDKULugNsDMdlHeJQOMGVLYaSZt3KP6aWNSqFA1PHDg-10ceuTEtq
_vPE4-Gtev4N4K4Eudlj4Q.
AxY8DCtDaGlsbGljb3RoZQ.
Rxsjg6PIExcmGSF7LnSEkDqWIKfAw1wZz2XpabV5PwQsolKwEauWYZNE9Q1hZJEZ
The representation of this value is: The resulting Authentication Tag value is:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 83, 85, 48, 69, [125, 141, 148, 252, 124, 121, 85, 199, 215, 154, 42, 68, 149, 209,
120, 88, 122, 85, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 225, 48]
74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 75, 48, 104, 84, 77, 106, 85,
50, 73, 110, 48, 46, 90, 109, 110, 108, 113, 87, 103, 106, 88, 121,
113, 119, 106, 114, 55, 99, 88, 72, 121, 115, 56, 70, 55, 57, 97,
110, 73, 85, 73, 54, 74, 50, 85, 87, 100, 65, 121, 82, 81, 69, 99,
71, 66, 85, 45, 75, 80, 72, 115, 101, 80, 77, 57, 49, 48, 95, 82,
111, 84, 68, 71, 117, 49, 73, 87, 52, 48, 68, 110, 48, 100, 118, 99,
100, 86, 69, 106, 112, 74, 99, 80, 80, 78, 73, 98, 122, 87, 99, 77,
120, 68, 105, 49, 51, 49, 69, 106, 101, 103, 45, 98, 56, 86, 105, 87,
53, 89, 88, 53, 111, 82, 100, 89, 100, 105, 82, 52, 103, 77, 83, 68,
68, 66, 51, 109, 98, 107, 73, 110, 77, 78, 85, 70, 84, 45, 80, 75,
53, 67, 117, 90, 82, 110, 72, 66, 50, 114, 85, 75, 53, 102, 104, 80,
117, 70, 54, 88, 70, 113, 76, 76, 90, 67, 71, 53, 81, 95, 114, 74,
109, 54, 69, 118, 101, 120, 45, 88, 76, 99, 78, 81, 65, 74, 78, 97,
49, 45, 54, 67, 73, 85, 49, 50, 87, 106, 51, 109, 80, 69, 120, 120,
119, 57, 118, 98, 110, 115, 81, 68, 85, 55, 66, 52, 66, 102, 109,
104, 100, 121, 105, 102, 108, 76, 65, 55, 65, 101, 53, 90, 71, 111,
86, 82, 108, 51, 65, 95, 95, 121, 76, 80, 88, 120, 82, 106, 72, 70,
104, 112, 79, 101, 68, 112, 95, 97, 100, 120, 56, 78, 121, 101, 106,
70, 53, 99, 122, 57, 121, 68, 75, 85, 76, 117, 103, 78, 115, 68, 77,
100, 108, 72, 101, 74, 81, 79, 77, 71, 86, 76, 89, 97, 83, 90, 116,
51, 75, 80, 54, 97, 87, 78, 83, 113, 70, 65, 49, 80, 72, 68, 103, 45,
49, 48, 99, 101, 117, 84, 69, 116, 113, 95, 118, 80, 69, 52, 45, 71,
116, 101, 118, 52, 78, 52, 75, 52, 69, 117, 100, 108, 106, 52, 81,
46, 65, 120, 89, 56, 68, 67, 116, 68, 97, 71, 108, 115, 98, 71, 108,
106, 98, 51, 82, 111, 90, 81, 46, 82, 120, 115, 106, 103, 54, 80, 73,
69, 120, 99, 109, 71, 83, 70, 55, 76, 110, 83, 69, 107, 68, 113, 87,
73, 75, 102, 65, 119, 49, 119, 90, 122, 50, 88, 112, 97, 98, 86, 53,
80, 119, 81, 115, 111, 108, 75, 119, 69, 97, 117, 87, 89, 90, 78, 69,
57, 81, 49, 104, 90, 74, 69, 90]
A.2.11. JWE Integrity Value A.2.9. Encoded JWE Ciphertext
Compute the HMAC SHA-256 of this value using the CIK to create the Base64url encode the Ciphertext to create the Encoded JWE Ciphertext.
JWE Integrity Value. This result is: This result is:
[240, 181, 234, 49, 221, 9, 44, 107, 49, 49, 160, 121, 186, 131, 90, KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY
50, 152, 59, 185, 69, 191, 167, 141, 17, 149, 166, 71, 11, 3, 8, 203,
57]
A.2.12. Encoded JWE Integrity Value A.2.10. Encoded JWE Authentication Tag
Base64url encode the resulting JWE Integrity Value to create the Base64url encode the Authentication Tag to create the Encoded JWE
Encoded JWE Integrity Value. This result is: Authentication Tag. This result is:
8LXqMd0JLGsxMaB5uoNaMpg7uUW_p40RlaZHCwMIyzk fY2U_Hx5VcfXmipEldHhMA
A.2.13. Complete Representation A.2.11. Complete Representation
Assemble the final representation: The Compact Serialization of this Assemble the final representation: The Compact Serialization of this
result is the concatenation of the Encoded JWE Header, the Encoded result is the concatenation of the Encoded JWE Header, the Encoded
JWE Encrypted Key, the Encoded JWE Initialization Vector, the Encoded JWE Encrypted Key, the Encoded JWE Initialization Vector, the Encoded
JWE Ciphertext, and the Encoded JWE Integrity Value in that order, JWE Ciphertext, and the Encoded JWE Authentication Tag in that order,
with the five strings being separated by four period ('.') with the five strings being separated by four period ('.')
characters. characters.
The final result in this example (with line breaks for display The final result in this example (with line breaks for display
purposes only) is: purposes only) is:
eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDK0hTMjU2In0. eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.
ZmnlqWgjXyqwjr7cXHys8F79anIUI6J2UWdAyRQEcGBU-KPHsePM910_RoTDGu1I nJa_uE2D0wlKz-OcwSbKFzj302xYSI-RLBM6hbVGmP4axtJQPA9S0po3s3NMkmOm
W40Dn0dvcdVEjpJcPPNIbzWcMxDi131Ejeg-b8ViW5YX5oRdYdiR4gMSDDB3mbkI kkawnfwPNjpc0mc3z79cuQWkQPFQo-mDxmogz8dxBcheaTUg3ZvpbGCXxZjDYENR
nMNUFT-PK5CuZRnHB2rUK5fhPuF6XFqLLZCG5Q_rJm6Evex-XLcNQAJNa1-6CIU1 WiZ5M9BiLy09BIF5mHp85QL6XED1JEZMOh-1uT1lqPDcDD79qWtrCfEJmNmfsx5f
2Wj3mPExxw9vbnsQDU7B4BfmhdyiflLA7Ae5ZGoVRl3A__yLPXxRjHFhpOeDp_ad cB2PfAcVtQ0t_YmOXx5_Gu0it1nILKXLR2Ynf9mfLhEcC5LebpWyEHW6WzQ4iH9S
x8NyejF5cz9yDKULugNsDMdlHeJQOMGVLYaSZt3KP6aWNSqFA1PHDg-10ceuTEtq IcIupPV1iKCzmJcPrDBJ5Fc_KMBcXBinaS__wftNywaGgfi_NSsx24LxtK6fIkej
_vPE4-Gtev4N4K4Eudlj4Q. RlMBmCfxv0Tg8CtxpURigg.
AxY8DCtDaGlsbGljb3RoZQ. AxY8DCtDaGlsbGljb3RoZQ.
Rxsjg6PIExcmGSF7LnSEkDqWIKfAw1wZz2XpabV5PwQsolKwEauWYZNE9Q1hZJEZ. KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.
8LXqMd0JLGsxMaB5uoNaMpg7uUW_p40RlaZHCwMIyzk fY2U_Hx5VcfXmipEldHhMA
A.2.14. Validation A.2.12. Validation
This example illustrates the process of creating a JWE with a This example illustrates the process of creating a JWE with RSAES-
composite Authenticated Encryption algorithm created from a non- PKCS1-V1_5 and AES_CBC_HMAC_SHA2. These results can be used to
Authenticated Encryption algorithm by adding a separate integrity validate JWE decryption implementations for these algorithms. Note
check calculation. These results can be used to validate JWE that since the RSAES-PKCS1-V1_5 computation includes random values,
decryption implementations for these algorithms. Note that since the the encryption results above will not be completely reproducible.
RSAES-PKCS1-V1_5 computation includes random values, the encryption However, since the AES CBC computation is deterministic, the JWE
results above will not be completely reproducible. However, since Encrypted Ciphertext values will be the same for all encryptions
the AES CBC computation is deterministic, the JWE Encrypted performed using these inputs.
Ciphertext values will be the same for all encryptions performed
using these inputs.
A.3. Example JWE using AES Key Wrap and AES GCM A.3. Example JWE using AES Key Wrap and AES GCM
This example encrypts the plaintext "The true sign of intelligence is This example encrypts the plaintext "Live long and prosper." to the
not knowledge but imagination." to the recipient using AES Key Wrap recipient using AES Key Wrap and AES GCM. The representation of this
and AES GCM. The representation of this plaintext is: plaintext is:
[84, 104, 101, 32, 116, 114, 117, 101, 32, 115, 105, 103, 110, 32, [76, 105, 118, 101, 32, 108, 111, 110, 103, 32, 97, 110, 100, 32,
111, 102, 32, 105, 110, 116, 101, 108, 108, 105, 103, 101, 110, 99, 112, 114, 111, 115, 112, 101, 114, 46]
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]
A.3.1. JWE Header A.3.1. JWE Header
The following example JWE Header declares that: The following example JWE Header declares that:
o the Content Master Key is encrypted to the recipient using the AES o the Content Encryption Key is encrypted to the recipient using the
Key Wrap algorithm with a 128 bit key to produce the JWE Encrypted AES Key Wrap algorithm with a 128 bit key to produce the JWE
Key and Encrypted Key and
o the Plaintext is encrypted using the AES GCM algorithm with a 128 o the Plaintext is encrypted using the AES_128_CBC_HMAC_SHA_256
bit key to produce the Ciphertext. algorithm to produce the Ciphertext.
{"alg":"A128KW","enc":"A128GCM"} {"alg":"A128KW","enc":"A128CBC-HS256"}
A.3.2. Encoded JWE Header A.3.2. Encoded JWE Header
Base64url encoding the bytes of the UTF-8 representation of the JWE Base64url encoding the octets of the UTF-8 representation of the JWE
Header yields this Encoded JWE Header value: Header yields this Encoded JWE Header value:
eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIn0 eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0
A.3.3. Content Master Key (CMK) A.3.3. Content Encryption Key (CEK)
Generate a 128 bit random Content Master Key (CMK). In this example, Generate a 256 bit random Content Encryption Key (CEK). In this
the value is: example, the value is:
[64, 154, 239, 170, 64, 40, 195, 99, 19, 84, 192, 142, 192, 238, 207, [4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106,
217] 206, 107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156,
44, 207]
A.3.4. Key Encryption A.3.4. Key Encryption
Encrypt the CMK with the shared symmetric key using the AES Key Wrap Encrypt the CEK with the shared symmetric key using the AES Key Wrap
algorithm to produce the JWE Encrypted Key. In this example, the algorithm to produce the JWE Encrypted Key. In this example, the
shared symmetric key value is: shared symmetric key value is:
[25, 172, 32, 130, 225, 114, 26, 181, 138, 106, 254, 192, 95, 133, [25, 172, 32, 130, 225, 114, 26, 181, 138, 106, 254, 192, 95, 133,
74, 82] 74, 82]
The resulting JWE Encrypted Key value is: The resulting JWE Encrypted Key value is:
[164, 255, 251, 1, 64, 200, 65, 200, 34, 197, 81, 143, 43, 211, 240, [232, 160, 123, 211, 183, 76, 245, 132, 200, 128, 123, 75, 190, 216,
38, 191, 161, 181, 117, 119, 68, 44, 80] 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]
A.3.5. Encoded JWE Encrypted Key A.3.5. Encoded JWE Encrypted Key
Base64url encode the JWE Encrypted Key to produce the Encoded JWE Base64url encode the JWE Encrypted Key to produce the Encoded JWE
Encrypted Key. This result is: Encrypted Key. This result is:
pP_7AUDIQcgixVGPK9PwJr-htXV3RCxQ 6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ
A.3.6. Initialization Vector A.3.6. Initialization Vector
Generate a random 96 bit JWE Initialization Vector. In this example, Generate a random 128 bit JWE Initialization Vector. In this
the value is: example, the value is:
[253, 220, 80, 25, 166, 152, 178, 168, 97, 99, 67, 89] [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 Base64url encoding this value yields the Encoded JWE Initialization
Vector value: Vector value:
_dxQGaaYsqhhY0NZ AxY8DCtDaGlsbGljb3RoZQ
A.3.7. "Additional Authenticated Data" Parameter A.3.7. Additional Authenticated Data Parameter
Concatenate the Encoded JWE Header value, a period character ('.'), Concatenate the Encoded JWE Header value, a period ('.') character,
the Encoded JWE Encrypted Key, a second period character ('.'), and and the Encoded JWE Encrypted Key to create the Additional
the Encoded JWE Initialization Vector to create the "additional Authenticated Data parameter. This result (with line breaks for
authenticated data" parameter for the AES GCM algorithm. This result display purposes only) is:
(with line breaks for display purposes only) is:
eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIn0. eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.
pP_7AUDIQcgixVGPK9PwJr-htXV3RCxQ. 6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ
_dxQGaaYsqhhY0NZ
The representation of this value is: The representation of this value is:
[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 66, 77, 84, 73, 52, [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, 83, 49, 99, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66,
77, 84, 73, 52, 82, 48, 78, 78, 73, 110, 48, 46, 112, 80, 95, 55, 65, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73,
85, 68, 73, 81, 99, 103, 105, 120, 86, 71, 80, 75, 57, 80, 119, 74, 110, 48, 46, 54, 75, 66, 55, 48, 55, 100, 77, 57, 89, 84, 73, 103,
114, 45, 104, 116, 88, 86, 51, 82, 67, 120, 81, 46, 95, 100, 120, 81, 72, 116, 76, 118, 116, 103, 87, 81, 56, 109, 75, 119, 98, 111, 74,
71, 97, 97, 89, 115, 113, 104, 104, 89, 48, 78, 90] 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]
A.3.8. Plaintext Encryption A.3.8. Plaintext Encryption
Encrypt the Plaintext with AES GCM using the CMK as the encryption Encrypt the Plaintext with AES_128_CBC_HMAC_SHA_256 using the CEK as
key, the JWE Initialization Vector, and the "additional authenticated the encryption key, the JWE Initialization Vector, and the Additional
data" value above, requesting a 128 bit "authentication tag" output. Authenticated Data value above. The steps for doing this using the
The resulting Ciphertext is: values from this example are detailed in Appendix B. The resulting
Ciphertext is:
[227, 12, 89, 132, 185, 16, 248, 93, 145, 87, 53, 130, 95, 115, 62, [40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6,
104, 138, 96, 109, 71, 124, 211, 165, 103, 202, 99, 21, 193, 4, 226, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143,
84, 229, 254, 106, 144, 241, 39, 86, 148, 132, 160, 104, 88, 232, 112, 56, 102]
228, 109, 85, 7, 86, 80, 134, 106, 166, 24, 92, 199, 210, 188, 153,
187, 218, 69, 227]
The resulting "authentication tag" value is: The resulting Authentication Tag value is:
[154, 35, 80, 107, 37, 148, 81, 6, 103, 4, 60, 206, 171, 165, 113, [8, 65, 248, 101, 45, 185, 28, 218, 232, 112, 83, 79, 84, 221, 18,
67] 172]
A.3.9. Encoded JWE Ciphertext A.3.9. Encoded JWE Ciphertext
Base64url encode the resulting Ciphertext to create the Encoded JWE Base64url encode the Ciphertext to create the Encoded JWE Ciphertext.
Ciphertext. This result (with line breaks for display purposes only) This result is:
is:
4wxZhLkQ-F2RVzWCX3M-aIpgbUd806VnymMVwQTiVOX-apDxJ1aUhKBoWOjkbVUH KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY
VlCGaqYYXMfSvJm72kXj
A.3.10. Encoded JWE Integrity Value A.3.10. Encoded JWE Authentication Tag
Base64url encode the resulting "authentication tag" to create the Base64url encode the Authentication Tag to create the Encoded JWE
Encoded JWE Integrity Value. This result is: Authentication Tag. This result is:
miNQayWUUQZnBDzOq6VxQw CEH4ZS25HNrocFNPVN0SrA
A.3.11. Complete Representation A.3.11. Complete Representation
Assemble the final representation: The Compact Serialization of this Assemble the final representation: The Compact Serialization of this
result is the concatenation of the Encoded JWE Header, the Encoded result is the concatenation of the Encoded JWE Header, the Encoded
JWE Encrypted Key, the Encoded JWE Initialization Vector, the Encoded JWE Encrypted Key, the Encoded JWE Initialization Vector, the Encoded
JWE Ciphertext, and the Encoded JWE Integrity Value in that order, JWE Ciphertext, and the Encoded JWE Authentication Tag in that order,
with the five strings being separated by four period ('.') with the five strings being separated by four period ('.')
characters. characters.
The final result in this example (with line breaks for display The final result in this example (with line breaks for display
purposes only) is: purposes only) is:
eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIn0. eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.
pP_7AUDIQcgixVGPK9PwJr-htXV3RCxQ. 6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ.
_dxQGaaYsqhhY0NZ. AxY8DCtDaGlsbGljb3RoZQ.
4wxZhLkQ-F2RVzWCX3M-aIpgbUd806VnymMVwQTiVOX-apDxJ1aUhKBoWOjkbVUH KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.
VlCGaqYYXMfSvJm72kXj. CEH4ZS25HNrocFNPVN0SrA
miNQayWUUQZnBDzOq6VxQw
A.3.12. Validation A.3.12. Validation
This example illustrates the process of creating a JWE with symmetric This example illustrates the process of creating a JWE with symmetric
key wrap and an Authenticated Encryption algorithm. These results key wrap and AES_CBC_HMAC_SHA2. These results can be used to
can be used to validate JWE decryption implementations for these validate JWE decryption implementations for these algorithms. Also,
algorithms. Also, since both the AES Key Wrap and AES GCM since both the AES Key Wrap and AES GCM computations are
computations are deterministic, the resulting JWE value will be the deterministic, the resulting JWE value will be the same for all
same for all encryptions performed using these inputs. Since the encryptions performed using these inputs. Since the computation is
computation is reproducible, these results can also be used to reproducible, these results can also be used to validate JWE
validate JWE encryption implementations for these algorithms. encryption implementations for these algorithms.
A.4. Example Key Derivation for "enc" value "A128CBC+HS256" Appendix B. Example AES_128_CBC_HMAC_SHA_256 Computation
This example uses the Concat KDF to derive the Content Encryption Key This example shows the steps in the AES_128_CBC_HMAC_SHA_256
(CEK) and Content Integrity Key (CIK) from the Content Master Key authenticated encryption computation using the values from the
(CMK) in the manner described in Section 4.8.1 of [JWA]. In this example in Appendix A.3. As described where this algorithm is
example, a 256 bit CMK is used to derive a 128 bit CEK and a 256 bit defined in Sections 4.8 and 4.8.3 of JWA, the AES_CBC_HMAC_SHA2
CIK. 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 CMK value used is: B.1. Extract MAC_KEY and ENC_KEY from Key
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, [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, 206, 107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156,
44, 207] 44, 207]
A.4.1. CEK Generation Use the first 128 bits of this key as the HMAC SHA-256 key MAC_KEY,
which is:
These values are concatenated to produce the round 1 hash input:
o the round number 1 as a 32 bit big endian integer ([0, 0, 0, 1]),
o the CMK value (as above),
o the output bit size 128 as a 32 bit big endian number ([0, 0, 0,
128]),
o the bytes of the UTF-8 representation of the "enc" value
"A128CBC+HS256" -- [65, 49, 50, 56, 67, 66, 67, 43, 72, 83, 50,
53, 54],
o the Datalen value of zero for the omitted "epu" (encryption
PartyUInfo) value ([0, 0, 0, 0]),
o the Datalen value of zero for the omitted "epv" (encryption
PartyVInfo) value ([0, 0, 0, 0]),
o the bytes of the ASCII representation of the label "Encryption" --
[69, 110, 99, 114, 121, 112, 116, 105, 111, 110].
Thus the round 1 hash input is:
[0, 0, 0, 1, 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, 0, 0, 0, 128, 65, 49, 50, 56, 67, 66, 67, 43,
72, 83, 50, 53, 54, 0, 0, 0, 0, 0, 0, 0, 0, 69, 110, 99, 114, 121,
112, 116, 105, 111, 110]
The SHA-256 hash of this value, which is the round 1 hash output, is:
[203, 165, 180, 113, 62, 195, 22, 98, 91, 153, 210, 38, 112, 35, 230,
236, 181, 193, 129, 233, 251, 107, 70, 80, 36, 150, 216, 251, 182,
29, 104, 150]
Given that 128 bits are needed for the CEK and the hash has produced
256 bits, the CEK value is the first 128 bits of that value:
[203, 165, 180, 113, 62, 195, 22, 98, 91, 153, 210, 38, 112, 35, 230,
236]
A.4.2. CIK Generation
These values are concatenated to produce the round 1 hash input:
o the round number 1 as a 32 bit big endian integer ([0, 0, 0, 1]),
o the CMK value (as above),
o the output bit size 256 as a 32 bit big endian number ([0, 0, 1,
0]),
o the bytes of the UTF-8 representation of the "enc" value
"A128CBC+HS256" -- [65, 49, 50, 56, 67, 66, 67, 43, 72, 83, 50,
53, 54],
o the Datalen value of zero for the omitted "epu" (encryption
PartyUInfo) value ([0, 0, 0, 0]),
o the Datalen value of zero for the omitted "epv" (encryption
PartyVInfo) value ([0, 0, 0, 0]),
o the bytes of the ASCII representation of the label "Integrity" --
[73, 110, 116, 101, 103, 114, 105, 116, 121].
Thus the round 1 hash input is:
[0, 0, 0, 1, 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, 0, 0, 1, 0, 65, 49, 50, 56, 67, 66, 67, 43,
72, 83, 50, 53, 54, 0, 0, 0, 0, 0, 0, 0, 0, 73, 110, 116, 101, 103,
114, 105, 116, 121]
The SHA-256 hash of this value, which is the round 1 hash output, is:
[218, 24, 160, 17, 160, 50, 235, 35, 216, 209, 100, 174, 155, 163,
10, 117, 180, 111, 172, 200, 127, 201, 206, 173, 40, 45, 58, 170, 35,
93, 9, 60]
Given that 256 bits are needed for the CIK and the hash has produced
256 bits, the CIK value is that same value:
[218, 24, 160, 17, 160, 50, 235, 35, 216, 209, 100, 174, 155, 163,
10, 117, 180, 111, 172, 200, 127, 201, 206, 173, 40, 45, 58, 170, 35,
93, 9, 60]
A.5. Example Key Derivation for "enc" value "A256CBC+HS512"
This example uses the Concat KDF to derive the Content Encryption Key
(CEK) and Content Integrity Key (CIK) from the Content Master Key
(CMK) in the manner described in Section 4.8.1 of [JWA]. In this
example, a 512 bit CMK is used to derive a 256 bit CEK and a 512 bit
CIK.
The CMK value used is:
[148, 116, 199, 126, 2, 117, 233, 76, 150, 149, 89, 193, 61, 34, 239,
226, 109, 71, 59, 160, 192, 140, 150, 235, 106, 204, 49, 176, 68,
119, 13, 34, 49, 19, 41, 69, 5, 20, 252, 145, 104, 129, 137, 138, 67,
23, 153, 83, 81, 234, 82, 247, 48, 211, 41, 130, 35, 124, 45, 156,
249, 7, 225, 168]
A.5.1. CEK Generation
These values are concatenated to produce the round 1 hash input:
o the round number 1 as a 32 bit big endian integer ([0, 0, 0, 1]),
o the CMK value (as above),
o the output bit size 256 as a 32 bit big endian number ([0, 0, 1,
0]),
o the bytes of the UTF-8 representation of the "enc" value [4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106,
"A256CBC+HS512" -- [65, 50, 53, 54, 67, 66, 67, 43, 72, 83, 53, 206]
49, 50],
o the Datalen value of zero for the omitted "epu" (encryption Use the last 128 bits of this key as the AES CBC key ENC_KEY, which
PartyUInfo) value ([0, 0, 0, 0]), is:
o the Datalen value of zero for the omitted "epv" (encryption [107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156, 44,
PartyVInfo) value ([0, 0, 0, 0]), 207]
o the bytes of the ASCII representation of the label "Encryption" -- Note that the MAC key comes before the encryption key in the input
[69, 110, 99, 114, 121, 112, 116, 105, 111, 110]. key K; this is in the opposite order of the algorithm names in the
identifiers "AES_128_CBC_HMAC_SHA_256" and "A128CBC-HS256".
Thus the round 1 hash input is: B.2. Encrypt Plaintext to Create Ciphertext
[0, 0, 0, 1, 148, 116, 199, 126, 2, 117, 233, 76, 150, 149, 89, 193, Encrypt the Plaintext with AES in Cipher Block Chaining (CBC) mode
61, 34, 239, 226, 109, 71, 59, 160, 192, 140, 150, 235, 106, 204, 49, using PKCS #5 padding using the ENC_KEY above. The Plaintext in this
176, 68, 119, 13, 34, 49, 19, 41, 69, 5, 20, 252, 145, 104, 129, 137, example is:
138, 67, 23, 153, 83, 81, 234, 82, 247, 48, 211, 41, 130, 35, 124,
45, 156, 249, 7, 225, 168, 0, 0, 1, 0, 65, 50, 53, 54, 67, 66, 67,
43, 72, 83, 53, 49, 50, 0, 0, 0, 0, 0, 0, 0, 0, 69, 110, 99, 114,
121, 112, 116, 105, 111, 110]
The SHA-512 hash of this value, which is the round 1 hash output, 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:
[157, 19, 75, 205, 31, 190, 110, 46, 117, 217, 137, 19, 116, 166, [40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6,
126, 60, 18, 244, 226, 114, 38, 153, 78, 198, 26, 0, 181, 168, 113, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143,
45, 149, 89, 107, 213, 109, 183, 207, 164, 86, 131, 51, 105, 214, 29, 112, 56, 102]
229, 32, 243, 46, 40, 53, 123, 4, 13, 7, 250, 48, 227, 207, 167, 211,
147, 91, 0, 171]
Given that 256 bits are needed for the CEK and the hash has produced B.3. Create 64 Bit Big Endian Representation of AAD Length
512 bits, the CEK value is the first 256 bits of that value:
[157, 19, 75, 205, 31, 190, 110, 46, 117, 217, 137, 19, 116, 166, The Additional Authenticated Data (AAD) in this example is:
126, 60, 18, 244, 226, 114, 38, 153, 78, 198, 26, 0, 181, 168, 113,
45, 149, 89]
A.5.2. CIK Generation [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]
These values are concatenated to produce the round 1 hash input: 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:
o the round number 1 as a 32 bit big endian integer ([0, 0, 0, 1]), [0, 0, 0, 0, 0, 0, 3, 80]
o the CMK value (as above), B.4. Initialization Vector Value
o the output bit size 512 as a 32 bit big endian number ([0, 0, 2, The Initialization Vector value used in this example is:
0]),
o the bytes of the UTF-8 representation of the "enc" value [3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104,
"A256CBC+HS512" -- [65, 50, 53, 54, 67, 66, 67, 43, 72, 83, 53, 101]
49, 50],
o the Datalen value of zero for the omitted "epu" (encryption B.5. Create Input to HMAC Computation
PartyUInfo) value ([0, 0, 0, 0]),
o the Datalen value of zero for the omitted "epv" (encryption Concatenate the AAD, the Initialization Vector, the Ciphertext, and
PartyVInfo) value ([0, 0, 0, 0]), the AL value. The result of this concatenation is:
o the bytes of the ASCII representation of the label "Integrity" -- [101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 66, 77, 84, 73, 52,
[73, 110, 116, 101, 103, 114, 105, 116, 121]. 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]
Thus the round 1 hash input is: B.6. Compute HMAC Value
[0, 0, 0, 1, 148, 116, 199, 126, 2, 117, 233, 76, 150, 149, 89, 193, Compute the HMAC SHA-256 of the concatenated value above. This
61, 34, 239, 226, 109, 71, 59, 160, 192, 140, 150, 235, 106, 204, 49, result M is:
176, 68, 119, 13, 34, 49, 19, 41, 69, 5, 20, 252, 145, 104, 129, 137,
138, 67, 23, 153, 83, 81, 234, 82, 247, 48, 211, 41, 130, 35, 124,
45, 156, 249, 7, 225, 168, 0, 0, 2, 0, 65, 50, 53, 54, 67, 66, 67,
43, 72, 83, 53, 49, 50, 0, 0, 0, 0, 0, 0, 0, 0, 73, 110, 116, 101,
103, 114, 105, 116, 121]
The SHA-512 hash of this value, which is the round 1 hash output, 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]
[81, 249, 131, 194, 25, 166, 147, 155, 47, 249, 146, 160, 200, 236, B.7. Truncate HMAC Value to Create Authentication Tag
115, 72, 103, 248, 228, 30, 130, 225, 164, 61, 105, 172, 198, 31,
137, 170, 215, 141, 27, 247, 73, 236, 125, 113, 151, 33, 0, 251, 72,
53, 72, 63, 146, 117, 247, 13, 49, 20, 210, 169, 232, 156, 118, 1,
16, 45, 29, 21, 15, 208]
Given that 512 bits are needed for the CIK and the hash has produced Use the first half (128 bits) of the HMAC output M as the
512 bits, the CIK value is that same value: Authentication Tag output T. This truncated value is:
[81, 249, 131, 194, 25, 166, 147, 155, 47, 249, 146, 160, 200, 236, [8, 65, 248, 101, 45, 185, 28, 218, 232, 112, 83, 79, 84, 221, 18,
115, 72, 103, 248, 228, 30, 130, 225, 164, 61, 105, 172, 198, 31, 172]
137, 170, 215, 141, 27, 247, 73, 236, 125, 113, 151, 33, 0, 251, 72,
53, 72, 63, 146, 117, 247, 13, 49, 20, 210, 169, 232, 156, 118, 1,
16, 45, 29, 21, 15, 208]
Appendix B. Acknowledgements Appendix C. Acknowledgements
Solutions for encrypting JSON content were also explored by JSON Solutions for encrypting JSON content were also explored by JSON
Simple Encryption [JSE] and JavaScript Message Security Format Simple Encryption [JSE] and JavaScript Message Security Format
[I-D.rescorla-jsms], both of which significantly influenced this [I-D.rescorla-jsms], both of which significantly influenced this
draft. This draft attempts to explicitly reuse as many of the draft. This draft attempts to explicitly reuse as many of the
relevant concepts from XML Encryption 1.1 relevant concepts from XML Encryption 1.1
[W3C.CR-xmlenc-core1-20120313] and RFC 5652 [RFC5652] as possible, [W3C.CR-xmlenc-core1-20120313] and RFC 5652 [RFC5652] as possible,
while utilizing simple compact JSON-based data structures. while utilizing simple compact JSON-based data structures.
Special thanks are due to John Bradley and Nat Sakimura for the Special thanks are due to John Bradley and Nat Sakimura for the
skipping to change at page 47, line 9 skipping to change at page 49, line 6
Richard Barnes, John Bradley, Brian Campbell, Breno de Medeiros, Dick Richard Barnes, John Bradley, Brian Campbell, Breno de Medeiros, Dick
Hardt, Jeff Hodges, Edmund Jay, James Manger, Tony Nadalin, Axel Hardt, Jeff Hodges, Edmund Jay, James Manger, Tony Nadalin, Axel
Nennker, Emmanuel Raviart, Nat Sakimura, Jim Schaad, Hannes Nennker, Emmanuel Raviart, Nat Sakimura, Jim Schaad, Hannes
Tschofenig, and Sean Turner. Tschofenig, and Sean Turner.
Jim Schaad and Karen O'Donoghue chaired the JOSE working group and Jim Schaad and Karen O'Donoghue chaired the JOSE working group and
Sean Turner and Stephen Farrell served as Security area directors Sean Turner and Stephen Farrell served as Security area directors
during the creation of this specification. during the creation of this specification.
Appendix C. Open Issues Appendix D. Document History
[[ to be removed by the RFC editor before publication as an RFC ]] [[ to be removed by the RFC editor before publication as an RFC ]]
The following items remain to be considered or done in this draft: -09
o Should all header fields continue to be required to be understood o Added JWE JSON Serialization, as specified by
by implementations using them or should a means of declaring that draft-jones-jose-jwe-json-serialization-04.
specific header fields may be safely ignored if not understood
should be defined?
Appendix D. Document History o Registered "application/jwe-js" MIME type and "JWE-JS" typ header
parameter value.
[[ to be removed by the RFC editor before publication as an RFC ]] o Defined that the default action for header parameters that are not
understood is to ignore them unless specifically designated as
"MUST be understood" or included in the new "crit" (critical)
header parameter list. This addressed issue #6.
o Corrected "x5c" description. This addressed issue #12.
o Changed from using the term "byte" to "octet" when referring to 8
bit values.
o Added Key Management Mode definitions to terminology section and
used the defined terms to provide clearer key management
instructions. This addressed issue #5.
o Added text about preventing the recipient from behaving as an
oracle during decryption, especially when using RSAES-PKCS1-V1_5.
o Changed from using the term "Integrity Value" to "Authentication
Tag".
o Changed member name from "integrity_value" to "authentication_tag"
in the JWE JSON Serialization.
o Removed Initialization Vector from the AAD value since it is
already integrity protected by all of the authenticated encryption
algorithms specified in the JWA specification.
o Replaced "A128CBC+HS256" and "A256CBC+HS512" with "A128CBC-HS256"
and "A256CBC-HS512". The new algorithms perform the same
cryptographic computations as [I-D.mcgrew-aead-aes-cbc-hmac-sha2],
but with the Initialization Vector and Authentication Tag values
remaining separate from the Ciphertext value in the output
representation. Also deleted the header parameters "epu"
(encryption PartyUInfo) and "epv" (encryption PartyVInfo), since
they are no longer used.
-08 -08
o Replaced uses of the term "AEAD" with "Authenticated Encryption", o Replaced uses of the term "AEAD" with "Authenticated Encryption",
since the term AEAD in the RFC 5116 sense implied the use of a since the term AEAD in the RFC 5116 sense implied the use of a
particular data representation, rather than just referring to the particular data representation, rather than just referring to the
class of algorithms that perform authenticated encryption with class of algorithms that perform authenticated encryption with
associated data. associated data.
o Applied editorial improvements suggested by Jeff Hodges and Hannes o Applied editorial improvements suggested by Jeff Hodges and Hannes
skipping to change at page 50, line 16 skipping to change at page 52, line 46
o Added Registry Contents sections to populate registry values. o Added Registry Contents sections to populate registry values.
o Numerous editorial improvements. o Numerous editorial improvements.
-02 -02
o When using Authenticated Encryption algorithms (such as AES GCM), o When using Authenticated Encryption algorithms (such as AES GCM),
use the "additional authenticated data" parameter to provide use the "additional authenticated data" parameter to provide
integrity for the header, encrypted key, and ciphertext and use integrity for the header, encrypted key, and ciphertext and use
the resulting "authentication tag" value as the JWE Integrity the resulting "authentication tag" value as the JWE Authentication
Value. Tag.
o Defined KDF output key sizes. o Defined KDF output key sizes.
o Generalized text to allow key agreement to be employed as an o Generalized text to allow key agreement to be employed as an
alternative to key wrapping or key encryption. alternative to key wrapping or key encryption.
o Changed compression algorithm from gzip to DEFLATE. o Changed compression algorithm from gzip to DEFLATE.
o Clarified that it is an error when a "kid" value is included and o Clarified that it is an error when a "kid" value is included and
no matching key is found. no matching key is found.
 End of changes. 261 change blocks. 
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