JOSE Working Group M. Jones Internet-Draft Microsoft Intended status: Standards Track~~March~~May12, 2012 Expires:~~September~~November13, 2012 JSON Web Algorithms (JWA)~~draft-ietf-jose-json-web-algorithms-01~~draft-ietf-jose-json-web-algorithms-02Abstract The JSON Web Algorithms (JWA) specification enumerates cryptographic algorithms and identifiers to be used with the JSON Web Signature (JWS) and JSON Web Encryption (JWE) specifications. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on~~September~~November13, 2012. Copyright Notice Copyright (c) 2012 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . .~~3~~42. Terminology . . . . . . . . . . . . . . . . . . . . . . . . .~~3~~43. Cryptographic Algorithms for JWS . . . . . . . . . . . . . . .~~3~~43.1.~~Creating a~~"alg" (Algorithm) Header Parameter Values forJWS. . . . 4 3.2. MACwith HMAC SHA-256, HMAC SHA-384, or HMAC SHA-512 . . .~~. . . . . . . . . . . . . . . . . . . . 4 3.2. Creating a JWS~~5 3.3. Digital Signaturewith RSA SHA-256, RSA SHA-384, or RSA SHA-512 . . . . . . . . . . . . . . . . . . . . . . .~~. . 5 3.3. Creating a JWS~~6 3.4. Digital Signaturewith ECDSA P-256 SHA-256, ECDSA P-384 SHA-384, or ECDSA P-521 SHA-512 . . . . . . . . . .~~. . . 6 3.4.~~7 3.5.Creating a Plaintext JWS . . . . . . . . . . . . . . . . .~~7 3.5.~~9 3.6.Additional Digital~~Signature/HMAC~~Signature/MACAlgorithmsand Parameters. . . . . . .~~7~~. . . . . . . . . . . . . . . . . 94. Cryptographic Algorithms for JWE . . . . . . . . . . . . . . .~~8~~94.1.~~Encrypting a~~"alg" (Algorithm) Header Parameter Values forJWE~~with TBD .~~. . . .9 4.2. "enc" (Encryption Method) Header Parameter Values for JWE. . . . . . . . . . .~~9 4.2. Additional Encryption Algorithms~~. . . . . . . . . . . . .~~9 5. IANA Considerations~~. . .10 4.3. "int" (Integrity Algorithm) Header Parameter Values for JWE. . . . . . . . . . . . . . . . . .~~10 6. Security Considerations~~. . . . . . .11 4.4. Key Encryption with RSA using RSA-PKCS1-1.5 Padding. . .11 4.5. Key Encryption with RSA using Optimal Asymmetric Encryption Padding (OAEP). . . . . . . . .~~10 7. Open Issues and Things To Be Done (TBD)~~. . . . . . .11 4.6. Key Agreement with Elliptic Curve Diffie-Hellman Ephemeral Static (ECDH-ES). . . .~~10 8. References~~. . . . . . . . . . . .12 4.7. Key Encryption with AES Key Wrap. . . . . . . . . . . . .12 4.8. Plaintext Encryption with AES Cipher Block Chaining (CBC) Mode.~~11 8.1. Normative References~~. . . . . . . . . . . . . . . . . . .~~11 8.2. Informative References~~. . . .12 4.9. Plaintext Encryption with AES Galois/Counter Mode (GCM).12 4.10. Integrity Calculation with HMAC SHA-256, HMAC SHA-384, or HMAC SHA-512. . . . . . . . . . . . .~~12 Appendix A. Digital Signature/HMAC Algorithm Identifier Cross-Reference~~. . . . . . . .13 4.11. Additional Encryption Algorithms and Parameters. . . . .13 5. Cryptographic Algorithms for JWK. . . . . .~~13 Appendix B. Encryption Algorithm Identifier Cross-Reference~~. . .~~15 Appendix C. Acknowledgements~~. . . . . .13 5.1. "alg" (Algorithm Family) Parameter Values for JWK. . . .14 5.2. JWK Parameters for Elliptic Curve Keys. . . . . . . .~~19 Appendix D. Document History~~. .14 5.2.1. "crv" (Curve) Parameter. . . . . . . . . . . . . . .14 5.2.2. "x" (X Coordinate) Parameter.~~19 Author's Address~~. . . . . . . . . . . .14 5.2.3. "y" (Y Coordinate) Parameter. . . . . . . . . . . . .~~19 1. Introduction The~~14 5.3. JWK Parameters for RSA Keys . . . . . . . . . . . . . . . 14 5.3.1. "mod" (Modulus) Parameter . . . . . . . . . . . . . . 15 5.3.2. "exp" (Exponent) Parameter . . . . . . . . . . . . . . 15 5.4. Additional Key Algorithm Families and Parameters . . . . . 15 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 6.1. JSON Web Signature and Encryption Header Parameters Registry . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.2.JSON WebSignature and EncryptionAlgorithms~~(JWA) specification enumerates cryptographic algorithms~~Registry . . 15 6.3. JSON Web Signature and Encryption "typ" Values Registry . 16 6.4. JSON Web Key Parameters Registry . . . . . . . . . . . . . 16 6.5. JSON Web Key Algorithm Families Registry . . . . . . . . . 16 7. Security Considerations . . . . . . . . . . . . . . . . . . . 16 8. Open Issues and Things To Be Done (TBD) . . . . . . . . . . . 17 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 9.1. Normative References . . . . . . . . . . . . . . . . . . . 17 9.2. Informative References . . . . . . . . . . . . . . . . . . 18 Appendix A. Digital Signature/MAC Algorithm Identifier Cross-Reference . . . . . . . . . . . . . . . . . . . 19 Appendix B. Encryption Algorithm Identifier Cross-Reference . . . 21 Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 25 Appendix D. Document History . . . . . . . . . . . . . . . . . . 25 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 26 1. Introduction The JSON Web Algorithms (JWA) specification enumerates cryptographic algorithms and identifiers to be used with the JSON Web Signature (JWS) [JWS] and JSON Web Encryption (JWE) [JWE] specifications. Enumerating the algorithms and identifiers for them in this specification, rather than in the JWS and JWE specifications, is intended to allow them to remain unchanged in the face of changes in the set of required, recommended, optional, and deprecated algorithms over time. This specification also describes the semantics and operations that are specific to these algorithms and algorithm families. 2. Terminology This specification uses the terminology defined by the JSON Web Signature (JWS) [JWS] and JSON Web Encryption (JWE) [JWE] specifications. 3. Cryptographic Algorithms for JWS JWS uses cryptographic algorithms to digitally sign or MAC the contents of the JWS Header and the JWS Payload. The use of the following algorithms for producing JWSs is defined in this section. 3.1. "alg" (Algorithm) Header Parameter Values for JWS The table below is the set of "alg" (algorithm) header parameter values defined by this specification for use with JWS, each of which is explained in more detail in the following sections: +--------------------+----------------------------------------------+ | alg Parameter | Digital Signature or MAC Algorithm | | Value | | +--------------------+----------------------------------------------+ | HS256 | HMAC using SHA-256 hash algorithm | | HS384 | HMAC using SHA-384 hash algorithm | | HS512 | HMAC using SHA-512 hash algorithm | | RS256 | RSA using SHA-256 hash algorithm | | RS384 | RSA using SHA-384 hash algorithm | | RS512 | RSA using SHA-512 hash algorithm | | ES256 | ECDSA using P-256 curve and SHA-256 hash | | | algorithm | | ES384 | ECDSA using P-384 curve and SHA-384 hash | | | algorithm | | ES512 | ECDSA using P-521 curve and SHA-512 hash | | | algorithm | | none | No digital signature or MAC value included | +--------------------+----------------------------------------------+ See Appendix A for a table cross-referencing the digital signature and MAC "alg" (algorithm) values used in this specification with the equivalent identifiers used by other standards and software packages. Of these algorithms, only HMAC SHA-256 and "none" MUST be implemented by conforming JWS implementations. It is RECOMMENDED that implementations also support the RSA SHA-256 and ECDSA P-256 SHA-256 algorithms. Support for other algorithms and key sizes is OPTIONAL. 3.2. MAC with HMAC SHA-256, HMAC SHA-384, or HMAC SHA-512 Hash-based Message Authentication Codes (HMACs) enable one to use a secret plus a cryptographic hash function to generate a Message Authentication Code (MAC). This can be used to demonstrate that the MAC matches the hashed content, in this case the JWS Secured Input, which therefore demonstrates that whoever generated the MAC was in possession of the secret. The means of exchanging the shared key is outside the scope of this specification. The algorithm for implementing and validating HMACs is provided in RFC 2104 [RFC2104]. This section defines the use of the HMAC SHA- 256, HMAC SHA-384, and HMAC SHA-512 cryptographic hash functions as defined in FIPS 180-3 [FIPS.180-3]. The "alg" (algorithm) header parameter values "HS256", "HS384",and~~identifiers to be~~"HS512" areused~~with~~inthe~~JSON Web~~JWS Header to indicate that the Encoded JWSSignature~~(JWS) [JWS] and JSON Web Encryption (JWE) [JWE] specifications. Enumerating~~contains a base64url encoded HMAC value usingthe~~algorithms and identifiers~~respective hash function. A key of the same size as the hash output (for instance, 256 bitsfor~~them in~~"HS256") or larger MUST be used withthis~~specification, rather than in~~algorithm. The HMAC SHA-256 MAC is generated as follows: 1. Apply the HMAC SHA-256 algorithm to the bytes of the UTF-8 representation ofthe JWS~~and JWE specifications,~~Secured Input (whichis~~intended~~the same as the ASCII representation) using the shared keyto~~allow them~~produce an HMAC value. 2. Base64url encode the resulting HMAC value. The output is the Encoded JWS Signature for that JWS. The HMAC SHA-256 MAC for a JWS is validated as follows: 1. Apply the HMAC SHA-256 algorithmto~~remain unchanged in~~the~~face~~bytesof~~changes in~~the~~set~~UTF-8 representationof~~required, recommended, optional, and deprecated algorithms over time. This specification also describes~~the~~semantics~~JWS Secured Input (which is the same as the ASCII representation) of the JWS using the shared key. 2. Base64url encode the resulting HMAC value. 3. If the Encoded JWS Signatureand~~operations~~the base64url encoded HMAC value exactly match, then one has confirmationthat~~are specific~~the shared key was usedto~~these algorithms~~generate the HMAC on the JWSand~~algorithm families. 2. Terminology This specification uses~~that the contents of the JWS have not be tampered with. 4. If the validation fails, the JWS MUST be rejected. Alternatively,the~~terminology defined by~~Encoded JWS Signature MAY be base64url decoded to producethe~~JSON Web~~JWSSignature~~(JWS) [JWS]~~and~~JSON Web Encryption (JWE) [JWE] specifications. 3. Cryptographic Algorithms for JWS JWS uses cryptographic~~this value can be compared with the computed HMAC value, as this comparison produces the same result as comparing the encoded values. Securing content with the HMAC SHA-384 and HMAC SHA-512algorithmsis performed identicallyto~~sign the contents of~~the~~JWS Header~~procedure for HMAC SHA-256 - just with correspondingly larger minimum key sizesandresult values. 3.3. Digital Signature with RSA SHA-256, RSA SHA-384, or RSA SHA-512 This section definesthe~~JWS Payload. The~~use of the~~following algorithms for producing JWSs is~~RSASSA-PKCS1-v1_5 digital signature algorithm asdefined in~~this section.~~RFC 3447 [RFC3447], Section 8.2 (commonly known as PKCS#1), using SHA-256, SHA-384, or SHA-512 as the hash function.The~~table below Table 1~~RSASSA-PKCS1-v1_5 algorithmisdescribed in FIPS 186-3 [FIPS.186-3], Section 5.5, andthe~~set of~~SHA-256, SHA-384, and SHA- 512 cryptographic hash functions are defined in FIPS 180-3 [FIPS.180-3]. The"alg" (algorithm) header parameter values~~defined by this specification for use with JWS, each of which is explained in more detail~~"RS256", "RS384", and "RS512" are usedin the~~following sections: +--------------------+----------------------------------------------+ | Alg Parameter | Algorithm | | Value | | +--------------------+----------------------------------------------+ | HS256 | HMAC using SHA-256 hash algorithm | | HS384 | HMAC using SHA-384 hash algorithm | | HS512 | HMAC using SHA-512 hash algorithm | | RS256 | RSA using SHA-256 hash algorithm | | RS384 | RSA using SHA-384 hash algorithm | | RS512 |~~JWS Header to indicate that the Encoded JWS Signature contains a base64url encodedRSAdigital signatureusing~~SHA-512~~the respectivehash~~algorithm | | ES256 | ECDSA using P-256 curve~~function. A key of size 2048 bits or larger MUST be used with these algorithms. Note that while Section 8 of RFC 3447 [RFC3447] explicitly calls for people not to adopt RSASSA-PKCS1 for new applicationsandinstead requests that people transition to RSASSA-PSS, for interoperability reasons, this specification does use RSASSA-PKCS1 because it commonly implemented. The RSASHA-256~~hash | | | algorithm | | ES384 | ECDSA using P-384 curve and SHA-384 hash | | | algorithm | | ES512 | ECDSA~~digital signature is generated as follows: 1. Generate a digital signature of the bytes of the UTF-8 representation of the JWS Secured Input (which is the same as the ASCII representation)using~~P-521 curve~~RSASSA-PKCS1-V1_5-SIGNand~~SHA-512~~the SHA- 256hash~~| | | algorithm | | none | No~~function with the desired private key. The output will be a byte array. 2. Base64url encode the resulting byte array. The output is the Encoded JWS Signature for that JWS. The RSA SHA-256digital signature~~or HMAC value included | +--------------------+----------------------------------------------+ Table 1: JWS Defined "alg" Parameter Values See Appendix A~~for a~~table cross-referencing~~JWS is validated as follows: 1. Takethe~~digital signature~~Encoded JWS Signatureand~~HMAC "alg" (algorithm) values used in this specification with~~base64url decode it into a byte array. If decoding fails,the~~equivalent identifiers used by other standards~~JWS MUST be rejected. 2. Submit the bytes of the UTF-8 representation of the JWS Secured Input (which is the same as the ASCII representation)and~~software packages. Of these algorithms, only HMAC~~the public key corresponding to the private key used by the signer to the RSASSA-PKCS1-V1_5-VERIFY algorithm usingSHA-256~~and "none"~~as the hash function. 3. If the validation fails, the JWSMUST be~~implemented by conforming JWS implementations. It is RECOMMENDED that implementations also support~~rejected. Signing withthe RSA~~SHA-256~~SHA-384and~~ECDSA P-256 SHA-256 algorithms. Support for other~~RSA SHA-512algorithms~~and key sizes~~is~~OPTIONAL. 3.1. Creating a JWS~~performed identically to the procedure for RSA SHA-256 - justwith~~HMAC~~correspondingly larger result values. 3.4. Digital Signature with ECDSA P-256SHA-256,~~HMAC~~ECDSA P-384SHA-384, or~~HMAC~~ECDSA P-521SHA-512~~Hash based Message Authentication Codes (HMACs) enable one to~~The Elliptic Curve Digital Signature Algorithm (ECDSA) is defined by FIPS 186-3 [FIPS.186-3]. ECDSA provides for theuse~~a secret plus a cryptographic hash function~~of Elliptic Curve cryptography, which is ableto~~generate a Message Authentication Code (MAC). This can be used~~provide equivalent securityto~~demonstrate that the MAC matches the hashed content, in this case the JWS Secured Input, which therefore demonstrates~~RSA cryptography but using shorter key sizes and with greater processing speed. This meansthat~~whoever generated the MAC was~~ECDSA digital signatures will be substantially smallerin~~possession~~termsoflength than equivalently strong RSA digital signatures. This specification definesthe~~secret. The means~~useof~~exchanging~~ECDSA withthe~~shared key is outside~~P-256 curve andthe~~scope of this specification. The algorithm for implementing~~SHA-256 cryptographic hash function, ECDSA with the P-384 curveand~~validating HMACs is provided in RFC 2104 [RFC2104]. This section defines~~the~~use of~~SHA-384 hash function, and ECDSA withthe~~HMAC SHA- 256, HMAC SHA-384,~~P-521 curve and the SHA-512 hash function. The P-256, P-384,and~~HMAC SHA-512 cryptographic hash functions as~~P-521 curves are alsodefined in FIPS~~180-3 [FIPS.180-3].~~186-3.The "alg" (algorithm) header parameter values~~"HS256", "HS384",~~"ES256", "ES384",and~~"HS512"~~"ES512"are used in the JWS Header to indicate that the Encoded JWS Signature contains a base64url encoded~~HMAC value using the respective hash function.~~ECDSA P-256 SHA-256, ECDSA P-384 SHA-384, or ECDSA P-521 SHA-512 digital signature, respectively. A key of size 160 bits or larger MUST be used with these algorithms.The~~HMAC~~ECDSA P-256SHA-256~~MAC~~digital signatureis generated as follows: 1.~~Apply~~Generate a digital signature ofthe~~HMAC SHA-256 algorithm to~~bytes ofthe UTF-8 representation of the JWS Secured Input(which is the same as the ASCII representation)usingECDSA P-256 SHA-256 withthe~~shared key to produce an HMAC value.~~desired private key. The output will be the EC point (R, S), where R and S are unsigned integers.2.Turn R and S into byte arrays in big endian order. Each array will be 32 bytes long. 3. Concatenate the two byte arrays in the order R and then S. 4.Base64url encode the resulting~~HMAC value.~~64 byte array.The output is the Encoded JWS Signature for~~that~~theJWS. The~~HMAC~~ECDSA P-256SHA-256~~MAC~~digital signaturefor a JWS is validated as follows: 1.~~Apply the HMAC SHA-256 algorithm to the UTF-8 representation of~~TaketheEncodedJWS~~Secured Input of~~Signature and base64url decode it into a byte array. If decoding fails,the JWS~~using the shared key.~~MUST be rejected.2.~~Base64url encode~~The output ofthe~~resulting HMAC value.~~base64url decoding MUST be a 64 byte array.3.~~If~~Splitthe~~Encoded JWS Signature~~64 byte array into two 32 byte arrays. The first array will be Rand the~~base64url encoded HMAC value exactly match, then one has confirmation that~~second S (with both being in big endian byte order). 4. Submitthe~~shared key was used to generate~~bytes ofthe~~HMAC on~~UTF-8 representation ofthe JWSSecured Input (which is the same as the ASCII representation), R, Sand~~that~~the~~contents of~~public key (x, y) tothe~~JWS have not be tampered with. 4.~~ECDSA P-256 SHA-256 validator. 5.If the validation fails, the JWS MUST be rejected.~~Alternatively,~~The ECDSA validator will then determine ifthe~~Encoded JWS Signature MAY be base64url decoded to produce~~digital signature is valid, giventhe~~JWS Signature and this~~inputs. Note that ECDSA digital signature contains avalue~~can be compared with the computed HMAC value,~~referred toas~~this comparison produces~~K, which is a random number generated for each digital signature instance. This means that two ECDSA digital signatures using exactlythe same~~result as comparing~~input parameters will output different signature values because their K values will be different. The consequence of this is that one must validate an ECDSA digital signature by submittingthe~~encoded values. Securing content~~previously specified inputs to an ECDSA validator. Signingwith the~~HMAC~~ECDSA P-384SHA-384 and~~HMAC~~ECDSA P-521SHA-512 algorithms is performed identically to the procedure for~~HMAC~~ECDSA P-256SHA-256 - just with correspondingly~~longer minimum key sizes and~~largerresult values.~~3.2.~~3.5.Creating aPlaintextJWS~~with RSA SHA-256, RSA SHA-384, or RSA SHA-512 This section defines the~~To supportuse~~of~~cases wherethe~~RSASSA-PKCS1-v1_5~~content is secured by a means other than adigital signature~~algorithm as~~or MAC value, JWSs MAY also be created without them. These are called "Plaintext JWSs". Plaintext JWSs MUST use the "alg" value "none", and are formatted identically to other JWSs, but with an empty JWS Signature value. 3.6. Additional Digital Signature/MAC Algorithms and Parameters Additional algorithms MAY be used to protect JWSs with corresponding "alg" (algorithm) header parameter values being defined to refer to them. New "alg" header parameter values SHOULD either bedefined in~~RFC 3447 [RFC3447],~~the IANA JSON Web Signature and Encryption Algorithms registrySection~~8.2 (commonly known as PKCS#1), using SHA-256, SHA-384,~~6.2or~~SHA-512 as~~be a URI that contains a collision resistant namespace. In particular, it is permissible to usethe~~hash function. The RSASSA-PKCS1-v1_5~~algorithm~~is described~~identifiers definedin~~FIPS 186-3 [FIPS.186-3], Section 5.5,~~XML DSIG [RFC3275], XML DSIG 2.0 [W3C.CR-xmldsig-core2-20120124],andrelated specifications as "alg" values. As indicated bythe~~SHA-256, SHA-384,~~common registry, JWSsand~~SHA- 512 cryptographic hash functions are defined in FIPS 180-3 [FIPS.180-3]. The~~JWEs share a common"alg"~~(algorithm) header parameter~~value space. Thevalues~~"RS256", "RS384", and "RS512" are~~used~~in the JWS Header to indicate that the Encoded JWS Signature contains a base64url encoded RSA digital signature using~~bythe~~respective hash function. A 2048-bit or longer key length~~two specificationsMUST be~~used with this algorithm. The RSA SHA-256 digital signature is generated~~distinct,as~~follows: 1. Generate a digital signature of~~the~~UTF-8 representation of~~"alg" value MAY be used to determine whethertheobject is aJWS~~Secured Input using RSASSA-PKCS1-V1_5-SIGN and~~or JWE. Likewise, additional reserved header parameter names MAY be defined viathe~~SHA-256 hash function with~~IANA JSON Web Signature and Encryption Header Parameters registry Section 6.1. As indicated bythe~~desired private key. The output will be~~common registry, JWSs and JWEs sharea~~byte array. 2. Base64url encode the resulting byte array. The output~~common header parameter space; when a parameterisused by both specifications, its usage must be compatible betweenthe~~Encoded JWS Signature for that JWS. The RSA SHA-256 digital signature~~specifications. 4. Cryptographic Algorithmsfor~~a JWS is validated as follows: 1. Take~~JWE JWE uses cryptographic algorithms to encryptthe~~Encoded JWS Signature~~Content Master Key (CMK)and~~base64url decode it into a byte array. If decoding fails,~~the~~JWS MUST be rejected. 2. Submit~~Plaintext. This section specifies a set of specific algorithms for these purposes. 4.1. "alg" (Algorithm) Header Parameter Values for JWE The table below isthe~~UTF-8 representation~~setof"alg" (algorithm) header parameter values that are defined by this specification for use with JWE. These algorithms are used to encryptthe~~JWS Secured Input and~~CMK, producingthe~~public key corresponding~~JWE Encrypted Key, orto~~the private~~usekey~~used by the signer~~agreementtoagree uponthe~~RSASSA-PKCS1-V1_5-VERIFY algorithm~~CMK. +-----------+-------------------------------------------------------+ | alg | Key Encryption or Agreement Algorithm | | Parameter | | | Value | | +-----------+-------------------------------------------------------+ | RSA1_5 | RSAusing~~SHA-256~~RSA-PKCS1-1.5 padding,as~~the hash function. 3. If the validation fails, the JWS MUST be rejected. Signing with the~~defined in RFC | | | 3447 [RFC3447] | | RSA-OAEP |RSA~~SHA-384~~using Optimal Asymmetric Encryption Padding | | | (OAEP), as defined in RFC 3447 [RFC3447] | | ECDH-ES | Elliptic Curve Diffie-Hellman Ephemeral Static, as | | | defined in RFC 6090 [RFC6090],and~~RSA SHA-512 algorithms is performed identically to~~usingthe~~procedure for RSA~~Concat | | | KDF, as defined in Section 5.8.1 of [NIST.800-56A], | | | where the Digest Method isSHA-256~~- just with correspondingly longer minimum key sizes~~and~~result values. 3.3. Creating a JWS with ECDSA P-256 SHA-256, ECDSA P-384 SHA-384, or ECDSA P-521 SHA-512 The Elliptic Curve Digital Signature~~all OtherInfo | | | parameters are the empty bit string | | A128KW | Advanced Encryption Standard (AES) Key WrapAlgorithm~~(ECDSA) is~~| | | using 128 bit keys, as defined in RFC 3394 [RFC3394] | | A256KW | Advanced Encryption Standard (AES) Key Wrap Algorithm | | | using 256 bit keys, asdefined~~by FIPS 186-3 [FIPS.186-3]. ECDSA provides~~in RFC 3394 [RFC3394] | +-----------+-------------------------------------------------------+ 4.2. "enc" (Encryption Method) Header Parameter ValuesforJWE The table below isthe~~use~~setof~~Elliptic Curve cryptography, which is able to provide equivalent security to RSA cryptography but using shorter key lengths and with greater processing speed. This means~~"enc" (encryption method) header parameter valuesthat~~ECDSA digital signatures will be substantially smaller in terms of length than equivalently strong RSA digital signatures. This~~are defined by thisspecification~~defines the~~foruse~~of ECDSA with the P-256 curve and the SHA-256 cryptographic hash function, ECDSA~~withJWE. These algorithms are used to encryptthe~~P-384 curve and~~Plaintext, which producesthe~~SHA-384 hash function,~~Ciphertext. +-----------+-------------------------------------------------------+ | enc | Block Encryption Algorithm | | Parameter | | | Value | | +-----------+-------------------------------------------------------+ | A128CBC | Advanced Encryption Standard (AES) using 128 bit keys | | | in Cipher Block Chaining (CBC) mode using PKCS #5 | | | padding, as defined in [FIPS.197]and~~ECDSA with the P-521 curve~~[NIST.800-38A] | | A256CBC | Advanced Encryption Standard (AES) using 256 bit keys | | | in Cipher Block Chaining (CBC) mode using PKCS #5 | | | padding, as defined in [FIPS.197]and~~the SHA-512 hash function. The P-256, P-384,~~[NIST.800-38A] | | A128GCM | Advanced Encryption Standard (AES) using 128 bit keys | | | in Galois/Counter Mode (GCM), as defined in | | | [FIPS.197]and~~P-521 curves are also~~[NIST.800-38D] | | A256GCM | Advanced Encryption Standard (AES) using 256 bit keys | | | in Galois/Counter Mode (GCM), asdefined in~~FIPS 186-3. The~~| | | [FIPS.197] and [NIST.800-38D] | +-----------+-------------------------------------------------------+ See Appendix B for a table cross-referencing the encryption"alg" (algorithm)~~header parameter values "ES256", "ES384",~~and~~"ES512" are~~"enc" (encryption method) valuesused inthis specification withthe~~JWS Header to indicate~~equivalent identifiers used by other standards and software packages. Of these "alg" and "enc" algorithms, only RSA-PKCS1-1.5 with 2048 bit keys, AES-128-KW, AES-256-KW, AES-128-CBC, and AES-256-CBC MUST be implemented by conforming JWE implementations. It is RECOMMENDEDthat~~the Encoded JWS Signature contains a base64url encoded ECDSA P-256 SHA-256, ECDSA P-384 SHA-384, or ECDSA P-521 SHA-512 digital signature, respectively.~~implementations also support ECDH-ES with 256 bit keys, AES-128- GCM, and AES-256-GCM. Support for other algorithms and key sizes is OPTIONAL. 4.3. "int" (Integrity Algorithm) Header Parameter Values for JWEThe~~ECDSA P-256 SHA-256 digital signature~~table belowis~~generated as follows: 1. Generate a digital signature~~the setof"int" (integrity algorithm) header parameter values defined by this specification for use with JWE. Note that these arethe~~UTF-8 representation~~HMAC SHA subsetof the"alg" (algorithm) header parameter values defined for use withJWS~~Secured Input~~Section 3.1. /> +---------------------+-----------------------------------+ | int Parameter Value | Algorithm | +---------------------+-----------------------------------+ | HS256 | HMACusing~~ECDSA P-256~~SHA-256~~with the desired private key. The output will be the EC point (R, S), where R and S are unsigned integers. 2. Turn R and S into byte arrays in big endian order. Each array will be 32 bytes long. 3. Concatenate the two byte arrays in the order R and then S. 4. Base64url encode the resulting 64 byte array. The output~~hash algorithm | | HS384 | HMAC using SHA-384 hash algorithm | | HS512 | HMAC using SHA-512 hash algorithm | +---------------------+-----------------------------------+ Of these "int" algorithms, only HMAC SHA-256 MUST be implemented by conforming JWE implementations. ItisRECOMMENDED that implementations also supportthe~~Encoded JWS Signature for the JWS. The~~RSA SHA-256 andECDSA P-256 SHA-256~~digital signature for a JWS is validated as follows: 1. Take~~algorithms. 4.4. Key Encryption with RSA using RSA-PKCS1-1.5 Padding This section definesthe~~Encoded JWS Signature and base64url decode it into~~specifics of encryptinga~~byte array. If decoding fails, the JWS MUST be rejected. 2.~~JWE CMK with RSA using RSA-PKCS1-1.5 padding, as defined in RFC 3447 [RFC3447].The~~output~~"alg" header parameter value "RSA1_5" is used in this case. A keyof~~the base64url decoding~~size 2048 bits or largerMUST be~~a 64 byte array. 3. Split~~used with this algorithm. 4.5. Key Encryption with RSA using Optimal Asymmetric Encryption Padding (OAEP) This section definesthe~~64 byte array into two 32 byte arrays.~~specifics of encrypting a JWE CMK with RSA using Optimal Asymmetric Encryption Padding (OAEP), as defined in RFC 3447 [RFC3447].The~~first array will~~"alg" header parameter value "RSA-OAEP" is used in this case. A key of size 2048 bits or larger MUSTbe~~R and the second S. Remember that~~used with this algorithm. 4.6. Key Agreement with Elliptic Curve Diffie-Hellman Ephemeral Static (ECDH-ES) This section definesthe~~byte arrays are~~specifics of agreeing upon a JWE CMK with Elliptic Curve Diffie-Hellman Ephemeral Static, as definedin~~big endian byte order; please check~~RFC 6090 [RFC6090], and usingthe~~ECDSA validator~~Concat KDF, as definedin~~use to see what byte order it requires. 4. Submit the UTF-8 representation~~Section 5.8.1of[NIST.800-56A], wherethe~~JWS Secured Input, R, S and the public key (x, y) to the ECDSA P-256 SHA-256 validator. 5. If the validation fails, the JWS MUST be rejected. The ECDSA validator will then determine if the digital signature~~Digest Methodis~~valid, given~~SHA-256 and all OtherInfo parameters arethe~~inputs. Note that ECDSA digital signature contains a~~empty bit string. The "alg" header parametervalue~~referred to as K, which~~"ECDH-ES"is~~a random number generated~~used in this case. A key of size 160 bits or larger MUST be usedfor~~each digital signature instance. This means that two ECDSA digital signatures using exactly~~the~~same input parameters will~~Elliptic Curve keys used with this algorithm. Theoutput~~different signature values because their K values will~~of the Concat KDF MUSTbe~~different. The consequence~~a keyof~~this is~~the same length asthat~~one must validate an ECDSA digital signature~~usedby~~submitting~~the~~previously specified inputs to an ECDSA validator. Signing with the ECDSA P-384 SHA-384 and ECDSA P-521 SHA-512 algorithms is performed identically to the procedure~~"enc" algorithm. An "epk" (ephemeral public key) value MUST only be usedfor~~ECDSA P-256 SHA-256 - just with correspondingly longer minimum key sizes and result values. 3.4. Creating~~a~~Plaintext JWS To support use cases where~~single key agreement transaction. 4.7. Key Encryption with AES Key Wrap This section definesthe~~content is secured by a means other than~~specifics of encryptinga~~digital signature or HMAC value, JWSs MAY also be created without them. These are called "Plaintext JWSs". Plaintext JWSs MUST use~~JWE CMK withtheAdvanced Encryption Standard (AES) Key Wrap Algorithm using 128 or 256 bit keys, as defined in RFC 3394 [RFC3394]. The"alg"~~value "none", and~~header parameter values "A128KW" or "A256KW"are~~formatted identically to other JWSs, but with an empty JWS Signature value. 3.5. Additional Digital Signature/HMAC Algorithms Additional algorithms MAY be~~used~~to protect JWSs~~in this case. 4.8. Plaintext Encryption with AES Cipher Block Chaining (CBC) Mode This section defines the specifics of encrypting the JWE Plaintextwith~~corresponding "alg" (algorithm) header parameter values being~~Advanced Encryption Standard (AES) in Cipher Block Chaining (CBC) mode using PKCS #5 padding using 128 or 256 bit keys, asdefined~~to refer to them. New "alg"~~in [FIPS.197] and [NIST.800-38A]. The "enc"header parameter values~~SHOULD either be defined in the IANA JSON Web Signature Algorithms registry~~"A128CBC"or~~be a URI that contains a collision resistant namespace. In particular, it~~"A256CBC" are used in this case. Use of an Initialization Vector (IV) of size 128 bitsis~~permissible to use~~RECOMMENDED with this algorithm. 4.9. Plaintext Encryption with AES Galois/Counter Mode (GCM) This section definesthe~~algorithm identifiers~~specifics of encrypting the JWE Plaintext with Advanced Encryption Standard (AES) in Galois/Counter Mode (GCM) using 128 or 256 bit keys, asdefined in~~XML DSIG [RFC3275]~~[FIPS.197]and~~related specifications as "alg" values. 4. Cryptographic Algorithms~~[NIST.800-38D]. The "enc" header parameter values "A128GCM" or "A256GCM" are used in this case. Use of an Initialization Vector (IV) of size 96 bits is REQUIRED with this algorithm. The "additional authenticated data" parameter valuefor~~JWE JWE uses cryptographic algorithms to encrypt~~the~~Content Encryption Key (CEK) and~~encryption isthe~~Plaintext. This section specifies~~concatenation of the Encoded JWE Header,a~~set~~period ('.') character, and the Encoded JWE Encrypted Key. The requested sizeof~~specific algorithms~~the "authentication tag" output MUST be the same as the key size (for instance, 128 bitsfor~~these purposes. The table below Table 2~~"A128GCM"). As GCMisan AEAD algorithm,theJWE Integrity Value isset~~of "alg" (algorithm) header parameter values that are defined by this specification for use with JWE. These algorithms are used~~to~~encrypt~~bethe~~CEK, which produces~~"authentication tag" value produced by the encryption. 4.10. Integrity Calculation with HMAC SHA-256, HMAC SHA-384, or HMAC SHA-512 This section definesthespecifics of computing aJWE~~Encrypted Key. +-----------+-------------------------------------------------------+ | alg | Encryption Algorithm | | Parameter | | |~~IntegrityValue~~| | +-----------+-------------------------------------------------------+ | RSA1_5 | RSA using RSA-PKCS1-1.5 padding,~~with HMAC SHA-256, HMAC SHA-384, or HMAC SHA-512as defined in~~RFC | | | 3447 [RFC3447] | | RSA-OAEP | RSA using Optimal Asymmetric Encryption Padding | | | (OAEP), as defined~~FIPS 180-3 [FIPS.180-3]. The "int" header parameter values "HS256", "HS384", or "HS512" are usedin~~RFC 3447 [RFC3447] | | ECDH-ES | Elliptic Curve Diffie-Hellman Ephemeral Static,~~this case. A key of the same sizeas~~| | |~~the hash output (for instance, 256 bits for "HS256") or larger MUST be used with this algorithm. 4.11. Additional Encryption Algorithms and Parameters Additional algorithms MAY be used to protect JWEs with corresponding "alg" (algorithm), "enc" (encryption method), and "int" (integrity algorithm) header parameter values beingdefined~~in RFC 6090 [RFC6090],~~to refer to them. New "alg", "enc",and~~using the Concat | | | KDF, as~~"int" header parameter values SHOULD either bedefined in~~[NIST-800-56A], where~~the~~Digest | | | Method is SHA-256~~IANA JSON Web Signatureand~~all OtherInfo parameters are | | | the empty bit string | | A128KW | Advanced~~Encryption~~Standard (AES) Key Wrap Algorithm | | | using 128 bit keys, as~~Algorithms registry Section 6.2 or be a URI that contains a collision resistant namespace. In particular, it is permissible to use the algorithm identifiersdefined in~~RFC 3394 [RFC3394] | | A256KW | Advanced~~XMLEncryption~~Standard (AES) Key Wrap Algorithm | | | using 256 bit keys, as defined in RFC 3394 [RFC3394] | | A512KW | Advanced~~[W3C.REC-xmlenc-core-20021210], XMLEncryption~~Standard (AES) Key Wrap Algorithm | | | using 512 bit keys,~~1.1 [W3C.CR-xmlenc-core1-20120313], and related specificationsas~~defined in RFC 3394 [RFC3394] | | A128GCM | Advanced Encryption Standard (AES) using 128 bit keys | | | in Galois/Counter Mode,~~"alg", "enc", and "int" values. As indicated by the common registry, JWSs and JWEs share a common "alg" value space. The values used by the two specifications MUST be distinct,asthe "alg" value MAY be used to determine whether the object is a JWS or JWE. Likewise, additional reserved header parameter names MAY bedefined~~in [FIPS-197]~~via the IANA JSON Web Signatureand~~| | | [NIST-800-38D] | | A256GCM | Advanced~~Encryption~~Standard (AES) using 256 bit~~Header Parameters registry Section 6.1. As indicated by the common registry, JWSs and JWEs share a common header parameter space; when a parameter is used by both specifications, its usage must be compatible between the specifications. 5. Cryptographic Algorithms for JWK A JSON Web Key (JWK) [JWK] is a JSON data structure that represents a public key. A JSON Web Key Set (JWK Set) is a JSON data structure for representing a set of JWKs. This section specifies a set of algorithm families to be used for those publickeys~~| | | in Galois/Counter Mode, as defined in [FIPS-197]~~and~~| | | [NIST-800-38D] | +-----------+-------------------------------------------------------+ Table 2: JWE Defined~~the algorithm family specific parameters for representing those keys. 5.1."alg"(Algorithm Family)Parameter Valuesfor JWKThe table below~~Table 3~~is the set of~~"enc" (encryption method) header~~"alg" (algorithm family)parameter values that are defined~~by this specification for use with JWE. These algorithms are used to encrypt the Plaintext, which produces the Ciphertext. +-----------+-------------------------------------------------------+ | enc | Symmetric Encryption Algorithm | | Parameter | | | Value | | +-----------+-------------------------------------------------------+ | A128CBC | Advanced Encryption Standard (AES) using 128 bit keys | | | in Cipher Block Chaining mode, as defined in | | | [FIPS-197] and [NIST-800-38A] | | A256CBC | Advanced Encryption Standard (AES) using 256 bit keys | | | in Cipher Block Chaining mode, as defined in | | | [FIPS-197] and [NIST-800-38A] | | A128GCM | Advanced Encryption Standard (AES) using 128 bit keys | | | in Galois/Counter Mode, as defined~~by this specification for usein~~[FIPS-197] and | |~~JWKs. +---------------------+----------------------------------------+|~~[NIST-800-38D] | | A256GCM~~alg Parameter Value|~~Advanced Encryption Standard (AES) using 256 bit keys~~Algorithm Family|+---------------------+----------------------------------------+|EC|~~in Galois/Counter Mode, as defined in [FIPS-197] and~~Elliptic Curve [FIPS.186-3] key family| |RSA|~~[NIST-800-38D]~~RSA [RFC3447] key family|~~+-----------+-------------------------------------------------------+ Table 3: JWE Defined "enc" Parameter Values See Appendix B~~+---------------------+----------------------------------------+ 5.2. JWK Parametersfor~~a table cross-referencing~~Elliptic Curve Keys JWKs can represent Elliptic Curve [FIPS.186-3] keys. In this case,the~~encryption~~"alg"~~(algorithm) and "enc" (encryption method) values~~member value MUST be "EC". Furthermore, these additional members MUST be present: 5.2.1. "crv" (Curve) Parameter The "crv" (curve) member identifies the cryptographic curveused~~in this specification~~with the~~equivalent identifiers used~~key. Values definedby~~other standards and software packages. Of these algorithms, only RSA-PKCS1-1.5 with 2048 bit keys, AES-128- CBC,~~this specification are "P-256", "P-384"and~~AES-256-CBC MUST~~"P-521". Additional "crv" values MAYbe~~implemented~~used, provided they are understoodby~~conforming JWE implementations.~~implementations using that Elliptic Curve key. The "crv" value is case sensitive. Its value MUST be a string. 5.2.2. "x" (X Coordinate) Parameter The "x" (x coordinate) member contains the x coordinate for the elliptic curve point.It is~~RECOMMENDED that implementations also support ECDH-ES with 256 bit keys, AES-128-GCM, and AES-256-GCM. Support~~represented as the base64url encoding of the coordinate's big endian representation. 5.2.3. "y" (Y Coordinate) Parameter The "y" (y coordinate) member contains the y coordinatefor~~other algorithms and key sizes~~the elliptic curve point. Itis~~OPTIONAL. 4.1. Encrypting a JWE with TBD TBD: Descriptions~~represented as the base64url encoding of the coordinate's big endian representation. 5.3. JWK Parameters for RSA Keys JWKs can represent RSA [RFC3447] keys. In this case, the "alg" member value MUST be "RSA". Furthermore, these additional members MUST be present: 5.3.1. "mod" (Modulus) Parameter The "mod" (modulus) member contains the modulus value for the RSA public key. It is represented as the base64url encodingof the~~particulars~~value's big endian representation. 5.3.2. "exp" (Exponent) Parameter The "exp" (exponent) member contains the exponent value for the RSA public key. It is represented as the base64url encodingofthe value's big endian representation. 5.4. Additional Key Algorithm Families and Parameters Public keysusing~~each specified encryption~~additionalalgorithm~~go here. 4.2. Additional Encryption Algorithms Additional algorithms MAY be used to protect JWEs~~families MAY be represented using JWK data structureswith corresponding "alg"~~(algorithm) and "enc" (encryption method) header~~(algorithm family)parameter values being defined to refer to them. New "alg"~~and "enc" header~~parameter values SHOULD either be defined in the IANA JSON Web~~Encryption Algorithms~~Key Algorithm FamiliesregistrySection 6.5or be a URI that contains a collision resistant namespace.~~In particular,~~Likewise, parameters for representing keys for additional algorithm families or additional key properties SHOULD either be defined in the IANA JSON Web Key Parameters registry Section 6.4 or be a URI that contains a collision resistant namespace. 6. IANA Considerations 6.1. JSON Web Signature and Encryption Header Parameters Registry This specification establishes the IANA JSON Web Signature and Encryption Header Parameters registry for reserved JWS and JWE header parameter names. Inclusion in the registry is RFC Required in the RFC 5226 [RFC5226] sense. The registry records the reserved header parameter name and a reference to the RFC that defines it. This specification registers the header parameter names defined in JSON Web Signature (JWS) [JWS], Section 4.1 and JSON Web Encryption (JWE) [JWE], Section 4.1. 6.2. JSON Web Signature and Encryption Algorithms Registry This specification establishes the IANA JSON Web Signature and Encryption Algorithms registry for values of the JWS and JWE "alg" (algorithm), "enc" (encryption method), and "int" (integrity algorithm) header parameters. Inclusion in the registry is RFC Required in the RFC 5226 [RFC5226] sense. The registry records the algorithm usage "alg", "enc", or "int", the value, and a pointer to the RFC that defines it. This specification registers the values defined in Section 3.1, Section 4.1, Section 4.2, and Section 4.3. 6.3. JSON Web Signature and Encryption "typ" Values Registry This specification establishes the IANA JSON Web Signature and Encryption "typ" Values registry for values of the JWS and JWE "typ" (type) header parameter. Inclusion in the registry is RFC Required in the RFC 5226 [RFC5226] sense. It is RECOMMENDED that all registered "typ" values also register a MIME Media Type RFC 2045 [RFC2045] that the registered value is a short name for. The registry records the "typ" value, the MIME type value thatit is~~permissible~~an abbreviation for (if any), and a pointerto~~use~~the~~algorithm identifiers defined in XML Encryption [W3C.REC-xmlenc-core-20021210], XML Encryption 1.1 [W3C.CR-xmlenc-core1-20110303], and related specifications~~RFC that defines it. MIME Media Type RFC 2045 [RFC2045] values MUST NOT be directly registeredas~~"alg" and "enc" values. 5. IANA Considerations~~new "typ" values; rather, new "typ" values MAY be registered as short names for MIME types. 6.4. JSON Web Key Parameters RegistryThis specification~~calls for: o A new~~establishes theIANA~~registry entitled "JSON~~JSONWeb~~Signature Algorithms"~~Key Parameters registryfor~~values of the JWS "alg" (algorithm) header~~reserved JWKparameter~~is defined in Section 3.5.~~names.Inclusion in the registry is RFC Required in the RFC 5226 [RFC5226] sense. The registry~~will just record~~recordsthe~~"alg" value~~reserved parameter nameand a~~pointer~~referenceto the RFC that defines it. This specification~~defines inclusion of~~registersthe~~algorithm values~~parameter namesdefined in~~Table 1. o A new IANA registry entitled "JSON~~JSON Web Key (JWK) [JWK], Section 4.2, JSONWeb Encryption~~Algorithms"~~(JWE) [JWE], Section 4.1, Section 5.2, and Section 5.3. 6.5. JSON Web Key Algorithm Families Registry This specification establishes the IANA JSON Web Key Algorithm Families registryfor values~~used with~~ofthe~~JWE~~JWK"alg"~~(algorithm) and "enc" (encryption method) header parameters is defined in Section 4.2.~~(algorithm family) parameter.Inclusion in the registry is RFC Required in the RFC 5226 [RFC5226] sense. The registry~~will record~~recordsthe "alg"~~or "enc"~~value and a pointer to the RFC that defines it. This specification~~defines inclusion of~~registersthe~~algorithm~~values defined in~~Table 2 and Table 3. 6. Security Considerations TBD 7. Open Issues and Things To Be Done (TBD) The following items remain to be done in this draft: o Specify minimum required key sizes for all algorithms. o Specify which algorithms require Initialization Vectors (IVs) and minimum required lengths for those IVs. o Since RFC 3447~~Section~~8 explicitly calls for people NOT to adopt RSASSA-PKCS1 for new applications and instead requests that people transition to RSASSA-PSS, we probably need some~~5.1. 7.Security~~Considerations text explaining why RSASSA-PKCS1 is being used (it's what's commonly implemented) and what the potential consequences are. o Should we define the use of RFC 5649 key wrapping functions, which allow arbitrary key sizes, in addition to the current use of RFC 3394 key wrapping functions, which require that keys be multiples of 64 bits? Is this needed in practice? o Decide whether to move the JWK algorithm family definitions "EC" and "RSA" here. This would likely result in all the family- specific parameter definitions also moving here ("crv", "x", "y", "mod", "exp"), leaving very little normative text~~Considerations The security considerationsin the~~JWK spec itself. This seems like it would reduce spec readability~~JWS, JWE,and~~so was not done. o It would be good~~JWK specifications also applyto~~say somewhere, in normative language, that eventually~~this specification. Eventuallythe algorithms and/or key sizes currently~~specified~~described in this specificationwill no longer be considered sufficiently secure and will be removed. Therefore, implementers~~MUST~~and deployments mustbe prepared for this eventuality.~~o Write the Security Considerations section.~~8.Open Issues and Things To Be Done (TBD) The following items remain to be done in this draft: o Find values for encryption algorithm cross-reference table currently listed as "TBD" or determine that they do not exist. 9.References~~8.1.~~9.1.Normative References~~[FIPS-197] National Institute of Standards and Technology (NIST), "Advanced Encryption Standard (AES)", FIPS PUB 197, November 2001.~~[FIPS.180-3] National Institute of Standards and Technology, "Secure Hash Standard (SHS)", FIPS PUB 180-3, October 2008. [FIPS.186-3] National Institute of Standards and Technology, "Digital Signature Standard (DSS)", FIPS PUB 186-3, June 2009.[FIPS.197] National Institute of Standards and Technology (NIST), "Advanced Encryption Standard (AES)", FIPS PUB 197, November 2001.[JWE] Jones, M., Rescorla, E., and J. Hildebrand, "JSON Web Encryption (JWE)",~~March~~May 2012. [JWK] Jones, M., "JSON Web Key (JWK)", May2012. [JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Signature (JWS)",~~March~~May2012.~~[NIST-800-38A]~~[NIST.800-38A]National Institute of Standards and Technology (NIST), "Recommendation for Block Cipher Modes of Operation", NIST PUB 800-38A, December 2001.~~[NIST-800-38D]~~[NIST.800-38D]National Institute of Standards and Technology (NIST), "Recommendation for Block Cipher Modes of Operation: Galois/Counter Mode (GCM) and GMAC", NIST PUB 800-38D, December 2001.~~[NIST-800-56A]~~[NIST.800-56A]National Institute of Standards and Technology (NIST), "Recommendation for Pair-Wise Key Establishment Schemes Using Discrete Logarithm Cryptography (Revised)", NIST PUB 800-56A, March 2007.[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996.[RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- Hashing for Message Authentication", RFC 2104, February 1997. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3394] Schaad, J. and R. Housley, "Advanced Encryption Standard (AES) Key Wrap Algorithm", RFC 3394, September 2002. [RFC3447] Jonsson, J. and B. Kaliski, "Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1", RFC 3447, February 2003. [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. [RFC6090] McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic Curve Cryptography Algorithms", RFC 6090, February 2011.~~8.2.~~9.2.Informative References [CanvasApp] Facebook, "Canvas Applications", 2010. [I-D.rescorla-jsms] Rescorla, E. and J. Hildebrand, "JavaScript Message Security Format", draft-rescorla-jsms-00 (work in progress), March 2011. [JCA] Oracle, "Java Cryptography Architecture", 2011. [JSE] Bradley, J. and N. Sakimura (editor), "JSON Simple Encryption", September 2010. [JSS] Bradley, J. and N. Sakimura (editor), "JSON Simple Sign", September 2010. [MagicSignatures] Panzer (editor), J., Laurie, B., and D. Balfanz, "Magic Signatures", January 2011. [RFC3275] Eastlake, D., Reagle, J., and D. Solo, "(Extensible Markup Language) XML-Signature Syntax and Processing", RFC 3275, March 2002.~~[W3C.CR-xmlenc-core1-20110303]~~[W3C.CR-xmldsig-core2-20120124] Eastlake, D., Reagle, J., Yiu, K., Solo, D., Datta, P.,Hirsch, F.,Cantor, S., and T.Roessler,~~T.,~~"XML Signature Syntax and Processing Version 2.0", World Wide Web Consortium CR CR-xmldsig-core2-20120124, January 2012, <http://www.w3.org/TR/2012/CR-xmldsig-core2-20120124>. [W3C.CR-xmlenc-core1-20120313] Eastlake, D.,Reagle, J.,Roessler, T.,and~~D. Eastlake,~~F. Hirsch,"XML Encryption Syntax and Processing Version 1.1", World Wide Web Consortium CR~~CR-xmlenc-core1-20110303,~~CR-xmlenc-core1-20120313,March~~2011, <http://www.w3.org/TR/2011/CR-xmlenc-core1-20110303>.~~2012, <http://www.w3.org/TR/2012/CR-xmlenc-core1-20120313>.[W3C.REC-xmlenc-core-20021210] Eastlake, D. and J. Reagle, "XML Encryption Syntax and Processing", World Wide Web Consortium Recommendation REC- xmlenc-core-20021210, December 2002, <http://www.w3.org/TR/2002/REC-xmlenc-core-20021210>. Appendix A. Digital~~Signature/HMAC~~Signature/MACAlgorithm Identifier Cross-Reference This appendix contains a table cross-referencing the digital signature and~~HMAC~~MAC"alg" (algorithm) values used in this specification with the equivalent identifiers used by other standards and software packages. See XML DSIG~~[RFC3275]~~[RFC3275], XML DSIG 2.0 [W3C.CR-xmldsig-core2-20120124],and Java Cryptography Architecture [JCA] for more information about the names defined by those documents. +-------+-----+----------------------------+----------+-------------+ | Algor | JWS | XML DSIG | JCA | OID | | ithm | | | | | +-------+-----+----------------------------+----------+-------------+ | HMAC | HS2 | http://www.w3.org/2001/04/ | HmacSHA2 | 1.2.840.113 | | using | 56 | xmldsig-more#hmac-sha256 | 56 | 549.2.9 | | SHA-2 | | | | | | 56 | | | | | | hash | | | | | | algo | | | | | | rithm | | | | | | HMAC | HS3 | http://www.w3.org/2001/04/ | HmacSHA3 | 1.2.840.113 | | using | 84 | xmldsig-more#hmac-sha384 | 84 | 549.2.10 | | SHA-3 | | | | | | 84 | | | | | | hash | | | | | | algo | | | | | | rithm | | | | | | HMAC | HS5 | http://www.w3.org/2001/04/ | HmacSHA5 | 1.2.840.113 | | using | 12 | xmldsig-more#hmac-sha512 | 12 | 549.2.11 | | SHA-5 | | | | | | 12 | | | | | | hash | | | | | | algo | | | | | | rithm | | | | | | RSA | RS2 | http://www.w3.org/2001/04/ | SHA256wi | 1.2.840.113 | | using | 56 | xmldsig-more#rsa-sha256 | thRSA | 549.1.1.11 | | SHA-2 | | | | | | 56 | | | | | | hash | | | | | | algo | | | | | | rithm | | | | | | RSA | RS3 | http://www.w3.org/2001/04/ | SHA384wi | 1.2.840.113 | | using | 84 | xmldsig-more#rsa-sha384 | thRSA | 549.1.1.12 | | SHA-3 | | | | | | 84 | | | | | | hash | | | | | | algo | | | | | | rithm | | | | | | RSA | RS5 | http://www.w3.org/2001/04/ | SHA512wi | 1.2.840.113 | | using | 12 | xmldsig-more#rsa-sha512 | thRSA | 549.1.1.13 | | SHA-5 | | | | | | 12 | | | | | | hash | | | | | | algo | | | | | | rithm | | | | | | ECDSA | ES2 | http://www.w3.org/2001/04/ | SHA256wi | 1.2.840.100 | | using | 56 | xmldsig-more#ecdsa-sha256 | thECDSA | 45.4.3.2 | | P-256 | | | | | | curve | | | | | | and | | | | | | SHA-2 | | | | | | 56 | | | | | | hash | | | | | | algo | | | | | | rithm | | | | | | ECDSA | ES3 | http://www.w3.org/2001/04/ | SHA384wi | 1.2.840.100 | | using | 84 | xmldsig-more#ecdsa-sha384 | thECDSA | 45.4.3.3 | | P-384 | | | | | | curve | | | | | | and | | | | | | SHA-3 | | | | | | 84 | | | | | | hash | | | | | | algo | | | | | | rithm | | | | | | ECDSA | ES5 | http://www.w3.org/2001/04/ | SHA512wi | 1.2.840.100 | | using | 12 | xmldsig-more#ecdsa-sha512 | thECDSA | 45.4.3.4 | | P-521 | | | | | | curve | | | | | | and | | | | | | SHA-5 | | | | | | 12 | | | | | | hash | | | | | | algo | | | | | | rithm | | | | | +-------+-----+----------------------------+----------+-------------+~~Table 4: Digital Signature/HMAC Algorithm Identifier Cross-Reference~~Appendix B. Encryption Algorithm Identifier Cross-Reference This appendix contains a table cross-referencing the "alg" (algorithm) and "enc" (encryption method) values used in this specification with the equivalent identifiers used by other standards and software packages. See XML Encryption [W3C.REC-xmlenc-core-20021210], XML Encryption 1.1~~[W3C.CR-xmlenc-core1-20110303],~~[W3C.CR-xmlenc-core1-20120313],and Java Cryptography Architecture [JCA] for more information about the names defined by those documents. +---------+-------+---------------------------+---------------------+ | Algorit | JWE | XML ENC | JCA | | hm | | | | +---------+-------+---------------------------+---------------------+ | RSA | RSA1_ | http://www.w3.org/2001/04 | RSA/ECB/PKCS1Paddin | | using | 5 | /xmlenc#rsa-1_5 | g | | RSA-PKC | | | | | S1-1.5 | | | | | paddin | | | | | g | | | | | RSA | RSA-O | http://www.w3.org/2001/04 | RSA/ECB/OAEPWithSHA | |~~using | AEP | /xmlenc#rsa-oaep-mgf1p | -1AndMGF1Padding | | Optimal | | | | | Asymmet | | | | | ric | | | | | Encryp | | | | | tion | | | | | Paddi | | | | | ng(OAEP | | | | | ) | | | | | Ellipti | ECDH- | http://www.w3.org/2009/xm | TBD | | cCurve | ES | lenc11#ECDH-ES | | | Diffie | | | | | -Hellma | | | | | n Ephem | | | | | eral | | | | | Stat~~using|AEP|/xmlenc#rsa-oaep-mgf1p|-1AndMGF1Padding| |~~ic~~Optimal| | | | |~~Advance~~Asymmet|~~A128K~~|~~http://www.w3.org/2001/04~~|~~TBD~~| |~~d~~ric|~~W~~|~~/xmlenc#kw-aes128~~| | | Encryp | | | | | tion | | | | |~~Stand~~Paddi| | | | |~~ard(AES~~ng(OAEP| | | | | )~~Key | | | | | Wrap~~| | | | |~~Algo~~Ellipti|ECDH-|http://www.w3.org/2009/xm|TBD| |~~rithm R~~cCurve|ES|lenc11#ECDH-ES| | |~~FC 339~~Diffie| | | | |~~4 [RF~~-Hellma| | | | |~~C3394]~~n Ephem| | | | |~~using12~~eral| | | | |~~8 bitke~~Stat| | | | |~~ys~~ic| | | | | Advance |~~A256K~~A128K| http://www.w3.org/2001/04 | TBD | | d | W |~~/xmlenc#kw-aes256~~/xmlenc#kw-aes128| | | Encryp | | | | | tion | | | | | Stand | | | | | ard(AES | | | | | ) Key | | | | | Wrap | | | | | Algo | | | | | rithm R | | | | | FC 339 | | | | | 4 [RF | | | | | C3394] | | | | |~~using25~~using12| | | | |~~6~~8bitke | | | | | ys | | | | | Advance |~~A512K~~A256K| http://www.w3.org/2001/04 | TBD | | d | W |~~/xmlenc#kw-aes512~~/xmlenc#kw-aes256| | | Encryp | | | | | tion | | | | | Stand | | | | | ard(AES | | | | | ) Key | | | | | Wrap | | | | | Algo | | | | | rithm R | | | | | FC 339 | | | | | 4 [RF | | | | | C3394] | | | | |~~using51~~using25| | | | |~~2~~6bitke | | | | | ys | | | | | Advance | A128C | http://www.w3.org/2001/04 | AES/CBC/PKCS5Paddin | | d | BC | /xmlenc#aes128-cbc | g | | Encryp | | | | | tion | | | | | Stand | | | | | ard(AES | | | | | ) usin | | | | | g 128 | | | | | bitkeys | | | | | inCiph | | | | | er Bloc | | | | | k Chai | | | | |~~ningmod~~ning(CB | | | | | C) mod| | | | | eusi | | | | | ng PKC | | | | | S #5pad | | | | | ding| | | | | Advance | A256C | http://www.w3.org/2001/04 | AES/CBC/PKCS5Paddin | | d | BC | /xmlenc#aes256-cbc | g | | Encryp | | | | | tion | | | | | Stand | | | | | ard(AES | | | | | ) usin | | | | | g 256 | | | | | bitkeys | | | | | inCiph | | | | | er Bloc | | | | | k Chai | | | | |~~ningmod~~ning(CB | | | | | C) mod| | | | | eusi | | | | | ng PKC | | | | | S #5pad | | | | | ding| | | | | Advance | A128G | http://www.w3.org/2009/xm | AES/GCM/NoPadding | | d | CM | lenc11#aes128-gcm | | | Encryp | | | | | tion | | | | | Stand | | | | | ard(AES | | | | | ) usin | | | | | g 128 | | | | | bitkeys | | | | | inGalo | | | | | is/Coun | | | | | ter Mod | | | | | e(GC | | | | | M)| | | | | Advance | A256G | http://www.w3.org/2009/xm | AES/GCM/NoPadding | | d | CM | lenc11#aes256-gcm | | | Encryp | | | | | tion | | | | | Stand | | | | | ard(AES | | | | | ) usin | | | | | g 256 | | | | | bitkeys | | | | | inGalo | | | | | is/Coun | | | | | ter Mod | | | | | e(GC | | | | | M)| | | | +---------+-------+---------------------------+---------------------+~~Table 5: Encryption Algorithm Identifier Cross-Reference~~Appendix C. Acknowledgements Solutions for signing and encrypting JSON content were previously explored by Magic Signatures [MagicSignatures], JSON Simple Sign [JSS], Canvas Applications [CanvasApp], JSON Simple Encryption [JSE], and JavaScript Message Security Format [I-D.rescorla-jsms], all of which influenced this draft. Dirk Balfanz, John Bradley, Yaron Y. Goland, John Panzer, Nat Sakimura, and Paul Tarjan all made significant contributions to the design of this specification and its related specifications. Appendix D. Document History-02 o For AES GCM, use the "additional authenticated data" parameter to provide integrity for the header, encrypted key, and ciphertext and use the resulting "authentication tag" value as the JWE Integrity Value. o Defined minimum required key sizes for algorithms without specified key sizes. o Defined KDF output key sizes. o Specified the use of PKCS #5 padding with AES-CBC. o Generalized text to allow key agreement to be employed as an alternative to key wrapping or key encryption. o Clarified that ECDH-ES is a key agreement algorithm. o Required implementation of AES-128-KW and AES-256-KW. o Removed the use of "A128GCM" and "A256GCM" for key wrapping. o Removed "A512KW" since it turns out that it's not a standard algorithm. o Clarified the relationship between "typ" header parameter values and MIME types. o Generalized language to refer to Message Authentication Codes (MACs) rather than Hash-based Message Authentication Codes (HMACs) unless in a context specific to HMAC algorithms. o Established registries: JSON Web Signature and Encryption Header Parameters, JSON Web Signature and Encryption Algorithms, JSON Web Signature and Encryption "typ" Values, JSON Web Key Parameters, and JSON Web Key Algorithm Families. o Moved algorithm-specific definitions from JWK to JWA. o Reformatted to give each member definition its own section heading.-01 o Moved definition of "alg":"none" for JWSs here from the JWT specification since this functionality is likely to be useful in more contexts that just for JWTs. o Added Advanced Encryption Standard (AES) Key Wrap Algorithm using 512 bit keys ("A512KW"). o Added text "Alternatively, the Encoded JWS Signature MAY be base64url decoded to produce the JWS Signature and this value can be compared with the computed HMAC value, as this comparison produces the same result as comparing the encoded values". o Corrected the Magic Signatures reference. o Made other editorial improvements suggested by JOSE working group participants. -00 o Created the initial IETF draft based upon draft-jones-json-web-signature-04 and draft-jones-json-web-encryption-02 with no normative changes. o Changed terminology to no longer call both digital signatures and HMACs "signatures". Author's Address Michael B. Jones Microsoft Email: mbj@microsoft.com URI: http://self-issued.info/