JSON Web Algorithms (JWA)
RFC 7518

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Internet Engineering Task Force (IETF)                          M. Jones
Request for Comments: 7518                                     Microsoft
Category: Standards Track                                       May 2015
ISSN: 2070-1721

                       JSON Web Algorithms (JWA)

Abstract

   This specification registers cryptographic algorithms and identifiers
   to be used with the JSON Web Signature (JWS), JSON Web Encryption
   (JWE), and JSON Web Key (JWK) specifications.  It defines several
   IANA registries for these identifiers.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7518.

Copyright Notice

   Copyright (c) 2015 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Jones                        Standards Track                    [Page 1]
RFC 7518                JSON Web Algorithms (JWA)               May 2015

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.1.  Notational Conventions  . . . . . . . . . . . . . . . . .   4
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Cryptographic Algorithms for Digital Signatures and MACs  . .   6
     3.1.  "alg" (Algorithm) Header Parameter Values for JWS . . . .   6
     3.2.  HMAC with SHA-2 Functions . . . . . . . . . . . . . . . .   7
     3.3.  Digital Signature with RSASSA-PKCS1-v1_5  . . . . . . . .   8
     3.4.  Digital Signature with ECDSA  . . . . . . . . . . . . . .   9
     3.5.  Digital Signature with RSASSA-PSS . . . . . . . . . . . .  10
     3.6.  Using the Algorithm "none"  . . . . . . . . . . . . . . .  11
   4.  Cryptographic Algorithms for Key Management . . . . . . . . .  11
     4.1.  "alg" (Algorithm) Header Parameter Values for JWE . . . .  12
     4.2.  Key Encryption with RSAES-PKCS1-v1_5  . . . . . . . . . .  13
     4.3.  Key Encryption with RSAES OAEP  . . . . . . . . . . . . .  14
     4.4.  Key Wrapping with AES Key Wrap  . . . . . . . . . . . . .  14
     4.5.  Direct Encryption with a Shared Symmetric Key . . . . . .  15
     4.6.  Key Agreement with Elliptic Curve Diffie-Hellman
           Ephemeral Static (ECDH-ES)  . . . . . . . . . . . . . . .  15
       4.6.1.  Header Parameters Used for ECDH Key Agreement . . . .  16
         4.6.1.1.  "epk" (Ephemeral Public Key) Header Parameter . .  16
         4.6.1.2.  "apu" (Agreement PartyUInfo) Header Parameter . .  17
         4.6.1.3.  "apv" (Agreement PartyVInfo) Header Parameter . .  17
       4.6.2.  Key Derivation for ECDH Key Agreement . . . . . . . .  17
     4.7.  Key Encryption with AES GCM . . . . . . . . . . . . . . .  18
       4.7.1.  Header Parameters Used for AES GCM Key Encryption . .  19
         4.7.1.1.  "iv" (Initialization Vector) Header Parameter . .  19
         4.7.1.2.  "tag" (Authentication Tag) Header Parameter . . .  19
     4.8.  Key Encryption with PBES2 . . . . . . . . . . . . . . . .  20
       4.8.1.  Header Parameters Used for PBES2 Key Encryption . . .  20
         4.8.1.1.  "p2s" (PBES2 Salt Input) Header Parameter . . . .  21
         4.8.1.2.  "p2c" (PBES2 Count) Header Parameter  . . . . . .  21
   5.  Cryptographic Algorithms for Content Encryption . . . . . . .  21
     5.1.  "enc" (Encryption Algorithm) Header Parameter Values for
           JWE . . . . . . . . . . . . . . . . . . . . . . . . . . .  22
     5.2.  AES_CBC_HMAC_SHA2 Algorithms  . . . . . . . . . . . . . .  22
       5.2.1.  Conventions Used in Defining AES_CBC_HMAC_SHA2  . . .  23
       5.2.2.  Generic AES_CBC_HMAC_SHA2 Algorithm . . . . . . . . .  23
         5.2.2.1.  AES_CBC_HMAC_SHA2 Encryption  . . . . . . . . . .  23
         5.2.2.2.  AES_CBC_HMAC_SHA2 Decryption  . . . . . . . . . .  25
       5.2.3.  AES_128_CBC_HMAC_SHA_256  . . . . . . . . . . . . . .  25
       5.2.4.  AES_192_CBC_HMAC_SHA_384  . . . . . . . . . . . . . .  26
       5.2.5.  AES_256_CBC_HMAC_SHA_512  . . . . . . . . . . . . . .  26