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'ITU.X690.1994' -- Possible downref: Non-RFC (?) normative reference: ref. 'JWA' -- Possible downref: Non-RFC (?) normative reference: ref. 'JWK' ** Downref: Normative reference to an Historic RFC: RFC 1421 ** Obsolete normative reference: RFC 2818 (Obsoleted by RFC 9110) ** Obsolete normative reference: RFC 4288 (Obsoleted by RFC 6838) ** Obsolete normative reference: RFC 4627 (Obsoleted by RFC 7158, RFC 7159) ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) ** Obsolete normative reference: RFC 5246 (Obsoleted by RFC 8446) -- Possible downref: Non-RFC (?) normative reference: ref. 'USA15' -- Possible downref: Non-RFC (?) normative reference: ref. 'USASCII' Summary: 6 errors (**), 0 flaws (~~), 1 warning (==), 26 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 JOSE Working Group M. Jones 3 Internet-Draft Microsoft 4 Intended status: Standards Track J. Bradley 5 Expires: January 31, 2013 Ping Identity 6 N. Sakimura 7 NRI 8 July 30, 2012 10 JSON Web Signature (JWS) 11 draft-ietf-jose-json-web-signature-05 13 Abstract 15 JSON Web Signature (JWS) is a means of representing content secured 16 with digital signatures or Message Authentication Codes (MACs) using 17 JavaScript Object Notation (JSON) data structures. Cryptographic 18 algorithms and identifiers for use with this specification are 19 described in the separate JSON Web Algorithms (JWA) specification. 20 Related encryption capabilities are described in the separate JSON 21 Web Encryption (JWE) specification. 23 Status of this Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at http://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on January 31, 2013. 40 Copyright Notice 42 Copyright (c) 2012 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (http://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 58 1.1. Notational Conventions . . . . . . . . . . . . . . . . . . 4 59 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 60 3. JSON Web Signature (JWS) Overview . . . . . . . . . . . . . . 5 61 3.1. Example JWS . . . . . . . . . . . . . . . . . . . . . . . 6 62 4. JWS Header . . . . . . . . . . . . . . . . . . . . . . . . . . 7 63 4.1. Reserved Header Parameter Names . . . . . . . . . . . . . 7 64 4.1.1. "alg" (Algorithm) Header Parameter . . . . . . . . . . 7 65 4.1.2. "jku" (JWK Set URL) Header Parameter . . . . . . . . . 8 66 4.1.3. "jwk" (JSON Web Key) Header Parameter . . . . . . . . 8 67 4.1.4. "x5u" (X.509 URL) Header Parameter . . . . . . . . . . 8 68 4.1.5. "x5t" (X.509 Certificate Thumbprint) Header 69 Parameter . . . . . . . . . . . . . . . . . . . . . . 8 70 4.1.6. "x5c" (X.509 Certificate Chain) Header Parameter . . . 9 71 4.1.7. "kid" (Key ID) Header Parameter . . . . . . . . . . . 9 72 4.1.8. "typ" (Type) Header Parameter . . . . . . . . . . . . 9 73 4.1.9. "cty" (Content Type) Header Parameter . . . . . . . . 10 74 4.2. Public Header Parameter Names . . . . . . . . . . . . . . 10 75 4.3. Private Header Parameter Names . . . . . . . . . . . . . . 10 76 5. Rules for Creating and Validating a JWS . . . . . . . . . . . 10 77 6. Securing JWSs with Cryptographic Algorithms . . . . . . . . . 12 78 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 79 7.1. JSON Web Signature and Encryption Header Parameters 80 Registry . . . . . . . . . . . . . . . . . . . . . . . . . 13 81 7.1.1. Registration Template . . . . . . . . . . . . . . . . 13 82 7.1.2. Initial Registry Contents . . . . . . . . . . . . . . 14 83 7.2. JSON Web Signature and Encryption Type Values Registry . . 15 84 7.2.1. Registration Template . . . . . . . . . . . . . . . . 15 85 7.2.2. Initial Registry Contents . . . . . . . . . . . . . . 16 86 7.3. Media Type Registration . . . . . . . . . . . . . . . . . 16 87 7.3.1. Registry Contents . . . . . . . . . . . . . . . . . . 16 88 8. Security Considerations . . . . . . . . . . . . . . . . . . . 17 89 8.1. Cryptographic Security Considerations . . . . . . . . . . 17 90 8.2. JSON Security Considerations . . . . . . . . . . . . . . . 18 91 8.3. Unicode Comparison Security Considerations . . . . . . . . 19 92 9. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 19 93 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19 94 10.1. Normative References . . . . . . . . . . . . . . . . . . . 19 95 10.2. Informative References . . . . . . . . . . . . . . . . . . 21 97 Appendix A. JWS Examples . . . . . . . . . . . . . . . . . . . . 21 98 A.1. JWS using HMAC SHA-256 . . . . . . . . . . . . . . . . . . 22 99 A.1.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 22 100 A.1.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 24 101 A.1.3. Validating . . . . . . . . . . . . . . . . . . . . . . 24 102 A.2. JWS using RSA SHA-256 . . . . . . . . . . . . . . . . . . 24 103 A.2.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 24 104 A.2.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 28 105 A.2.3. Validating . . . . . . . . . . . . . . . . . . . . . . 28 106 A.3. JWS using ECDSA P-256 SHA-256 . . . . . . . . . . . . . . 28 107 A.3.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 28 108 A.3.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 30 109 A.3.3. Validating . . . . . . . . . . . . . . . . . . . . . . 30 110 A.4. JWS using ECDSA P-521 SHA-512 . . . . . . . . . . . . . . 31 111 A.4.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 31 112 A.4.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 33 113 A.4.3. Validating . . . . . . . . . . . . . . . . . . . . . . 33 114 A.5. Example Plaintext JWS . . . . . . . . . . . . . . . . . . 34 115 Appendix B. "x5c" (X.509 Certificate Chain) Example . . . . . . . 34 116 Appendix C. Notes on implementing base64url encoding without 117 padding . . . . . . . . . . . . . . . . . . . . . . . 36 118 Appendix D. Acknowledgements . . . . . . . . . . . . . . . . . . 37 119 Appendix E. Document History . . . . . . . . . . . . . . . . . . 38 120 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 41 122 1. Introduction 124 JSON Web Signature (JWS) is a compact format for representing content 125 secured with digital signatures or Message Authentication Codes 126 (MACs) intended for space constrained environments such as HTTP 127 Authorization headers and URI query parameters. It represents this 128 content using JavaScript Object Notation (JSON) [RFC4627] based data 129 structures. The JWS cryptographic mechanisms provide integrity 130 protection for arbitrary sequences of bytes. 132 Cryptographic algorithms and identifiers for use with this 133 specification are described in the separate JSON Web Algorithms (JWA) 134 [JWA] specification. Related encryption capabilities are described 135 in the separate JSON Web Encryption (JWE) [JWE] specification. 137 1.1. Notational Conventions 139 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 140 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 141 document are to be interpreted as described in Key words for use in 142 RFCs to Indicate Requirement Levels [RFC2119]. 144 2. Terminology 146 JSON Web Signature (JWS) A data structure cryptographically securing 147 a JWS Header and a JWS Payload with a JWS Signature value. 149 JWS Header A string representing a JSON object that describes the 150 digital signature or MAC operation applied to create the JWS 151 Signature value. 153 JWS Payload The bytes to be secured - a.k.a., the message. The 154 payload can contain an arbitrary sequence of bytes. 156 JWS Signature A byte array containing the cryptographic material 157 that secures the JWS Header and the JWS Payload. 159 Base64url Encoding The URL- and filename-safe Base64 encoding 160 described in RFC 4648 [RFC4648], Section 5, with the (non URL- 161 safe) '=' padding characters omitted, as permitted by Section 3.2. 162 (See Appendix C for notes on implementing base64url encoding 163 without padding.) 165 Encoded JWS Header Base64url encoding of the bytes of the UTF-8 166 [RFC3629] representation of the JWS Header. 168 Encoded JWS Payload Base64url encoding of the JWS Payload. 170 Encoded JWS Signature Base64url encoding of the JWS Signature. 172 JWS Secured Input The concatenation of the Encoded JWS Header, a 173 period ('.') character, and the Encoded JWS Payload. 175 Header Parameter Name The name of a member of the JSON object 176 representing a JWS Header. 178 Header Parameter Value The value of a member of the JSON object 179 representing a JWS Header. 181 JWS Compact Serialization A representation of the JWS as the 182 concatenation of the Encoded JWS Header, the Encoded JWS Payload, 183 and the Encoded JWS Signature in that order, with the three 184 strings being separated by period ('.') characters. 186 Collision Resistant Namespace A namespace that allows names to be 187 allocated in a manner such that they are highly unlikely to 188 collide with other names. For instance, collision resistance can 189 be achieved through administrative delegation of portions of the 190 namespace or through use of collision-resistant name allocation 191 functions. Examples of Collision Resistant Namespaces include: 192 Domain Names, Object Identifiers (OIDs) as defined in the ITU-T 193 X.660 and X.670 Recommendation series, and Universally Unique 194 IDentifiers (UUIDs) [RFC4122]. When using an administratively 195 delegated namespace, the definer of a name needs to take 196 reasonable precautions to ensure they are in control of the 197 portion of the namespace they use to define the name. 199 StringOrURI A JSON string value, with the additional requirement 200 that while arbitrary string values MAY be used, any value 201 containing a ":" character MUST be a URI [RFC3986]. StringOrURI 202 values are compared as case-sensitive strings with no 203 transformations or canonicalizations applied. 205 3. JSON Web Signature (JWS) Overview 207 JWS represents digitally signed or MACed content using JSON data 208 structures and base64url encoding. The representation consists of 209 three parts: the JWS Header, the JWS Payload, and the JWS Signature. 210 In the Compact Serialization, the three parts are base64url-encoded 211 for transmission, and represented as the concatenation of the encoded 212 strings in that order, with the three strings being separated by 213 period ('.') characters. (A JSON Serialization for this information 214 is defined in the separate JSON Web Signature JSON Serialization 215 (JWS-JS) [JWS-JS] specification.) 217 The JWS Header describes the signature or MAC method and parameters 218 employed. The JWS Payload is the message content to be secured. The 219 JWS Signature ensures the integrity of both the JWS Header and the 220 JWS Payload. 222 3.1. Example JWS 224 The following example JWS Header declares that the encoded object is 225 a JSON Web Token (JWT) [JWT] and the JWS Header and the JWS Payload 226 are secured using the HMAC SHA-256 algorithm: 228 {"typ":"JWT", 229 "alg":"HS256"} 231 Base64url encoding the bytes of the UTF-8 representation of the JWS 232 Header yields this Encoded JWS Header value: 234 eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9 236 The following is an example of a JSON object that can be used as a 237 JWS Payload. (Note that the payload can be any content, and need not 238 be a representation of a JSON object.) 240 {"iss":"joe", 241 "exp":1300819380, 242 "http://example.com/is_root":true} 244 Base64url encoding the bytes of the UTF-8 representation of the JSON 245 object yields the following Encoded JWS Payload (with line breaks for 246 display purposes only): 248 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 249 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 251 Computing the HMAC of the bytes of the ASCII [USASCII] representation 252 of the JWS Secured Input (the concatenation of the Encoded JWS 253 Header, a period ('.') character, and the Encoded JWS Payload) with 254 the HMAC SHA-256 algorithm using the key specified in Appendix A.1 255 and base64url encoding the result yields this Encoded JWS Signature 256 value: 258 dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk 260 Concatenating these parts in the order Header.Payload.Signature with 261 period characters between the parts yields this complete JWS 262 representation (with line breaks for display purposes only): 264 eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9 265 . 266 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 267 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 268 . 269 dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk 271 This computation is illustrated in more detail in Appendix A.1. 273 4. JWS Header 275 The members of the JSON object represented by the JWS Header describe 276 the digital signature or MAC applied to the Encoded JWS Header and 277 the Encoded JWS Payload and optionally additional properties of the 278 JWS. The Header Parameter Names within this object MUST be unique; 279 JWSs with duplicate Header Parameter Names MUST be rejected. 280 Implementations MUST understand the entire contents of the header; 281 otherwise, the JWS MUST be rejected. 283 There are three classes of Header Parameter Names: Reserved Header 284 Parameter Names, Public Header Parameter Names, and Private Header 285 Parameter Names. 287 4.1. Reserved Header Parameter Names 289 The following header parameter names are reserved with meanings as 290 defined below. All the names are short because a core goal of JWSs 291 is for the representations to be compact. 293 Additional reserved header parameter names MAY be defined via the 294 IANA JSON Web Signature and Encryption Header Parameters registry 295 Section 7.1. As indicated by the common registry, JWSs and JWEs 296 share a common header parameter space; when a parameter is used by 297 both specifications, its usage must be compatible between the 298 specifications. 300 4.1.1. "alg" (Algorithm) Header Parameter 302 The "alg" (algorithm) header parameter identifies the cryptographic 303 algorithm used to secure the JWS. The algorithm specified by the 304 "alg" value MUST be supported by the implementation and there MUST be 305 a key for use with that algorithm associated with the party that 306 digitally signed or MACed the content or the JWS MUST be rejected. 307 "alg" values SHOULD either be registered in the IANA JSON Web 308 Signature and Encryption Algorithms registry [JWA] or be a URI that 309 contains a Collision Resistant Namespace. The "alg" value is a case 310 sensitive string containing a StringOrURI value. This header 311 parameter is REQUIRED. 313 A list of defined "alg" values can be found in the IANA JSON Web 314 Signature and Encryption Algorithms registry [JWA]; the initial 315 contents of this registry is the values defined in Section 3.1 of the 316 JSON Web Algorithms (JWA) [JWA] specification. 318 4.1.2. "jku" (JWK Set URL) Header Parameter 320 The "jku" (JWK Set URL) header parameter is a URI [RFC3986] that 321 refers to a resource for a set of JSON-encoded public keys, one of 322 which corresponds to the key used to digitally sign the JWS. The 323 keys MUST be encoded as a JSON Web Key Set (JWK Set) [JWK]. The 324 protocol used to acquire the resource MUST provide integrity 325 protection; an HTTP GET request to retrieve the certificate MUST use 326 TLS [RFC2818] [RFC5246]; the identity of the server MUST be 327 validated, as per Section 3.1 of HTTP Over TLS [RFC2818]. This 328 header parameter is OPTIONAL. 330 4.1.3. "jwk" (JSON Web Key) Header Parameter 332 The "jwk" (JSON Web Key) header parameter is a public key that 333 corresponds to the key used to digitally sign the JWS. This key is 334 represented as a JSON Web Key [JWK]. This header parameter is 335 OPTIONAL. 337 4.1.4. "x5u" (X.509 URL) Header Parameter 339 The "x5u" (X.509 URL) header parameter is a URI [RFC3986] that refers 340 to a resource for the X.509 public key certificate or certificate 341 chain [RFC5280] corresponding to the key used to digitally sign the 342 JWS. The identified resource MUST provide a representation of the 343 certificate or certificate chain that conforms to RFC 5280 [RFC5280] 344 in PEM encoded form [RFC1421]. The certificate containing the public 345 key of the entity that digitally signed the JWS MUST be the first 346 certificate. This MAY be followed by additional certificates, with 347 each subsequent certificate being the one used to certify the 348 previous one. The protocol used to acquire the resource MUST provide 349 integrity protection; an HTTP GET request to retrieve the certificate 350 MUST use TLS [RFC2818] [RFC5246]; the identity of the server MUST be 351 validated, as per Section 3.1 of HTTP Over TLS [RFC2818]. This 352 header parameter is OPTIONAL. 354 4.1.5. "x5t" (X.509 Certificate Thumbprint) Header Parameter 356 The "x5t" (X.509 Certificate Thumbprint) header parameter provides a 357 base64url encoded SHA-1 thumbprint (a.k.a. digest) of the DER 358 encoding of the X.509 certificate [RFC5280] corresponding to the key 359 used to digitally sign the JWS. This header parameter is OPTIONAL. 361 If, in the future, certificate thumbprints need to be computed using 362 hash functions other than SHA-1, it is suggested that additional 363 related header parameters be defined for that purpose. For example, 364 it is suggested that a new "x5t#S256" (X.509 Certificate Thumbprint 365 using SHA-256) header parameter could be defined by registering it in 366 the IANA JSON Web Signature and Encryption Header Parameters registry 367 Section 7.1. 369 4.1.6. "x5c" (X.509 Certificate Chain) Header Parameter 371 The "x5c" (X.509 Certificate Chain) header parameter contains the 372 X.509 public key certificate or certificate chain [RFC5280] 373 corresponding to the key used to digitally sign the JWS. The 374 certificate or certificate chain is represented as an array of 375 certificate values. Each value is a base64 encoded ([RFC4648] 376 Section 4 - not base64url encoded) DER [ITU.X690.1994] PKIX 377 certificate value. The certificate containing the public key of the 378 entity that digitally signed the JWS MUST be the first certificate. 379 This MAY be followed by additional certificates, with each subsequent 380 certificate being the one used to certify the previous one. The 381 recipient MUST verify the certificate chain according to [RFC5280] 382 and reject the JWS if any validation failure occurs. This header 383 parameter is OPTIONAL. 385 See Appendix B for an example "x5c" value. 387 4.1.7. "kid" (Key ID) Header Parameter 389 The "kid" (key ID) header parameter is a hint indicating which key 390 was used to secure the JWS. This parameter allows originators to 391 explicitly signal a change of key to recipients. Should the 392 recipient be unable to locate a key corresponding to the "kid" value, 393 they SHOULD treat that condition as an error. The interpretation of 394 the "kid" value is unspecified. Its value MUST be a string. This 395 header parameter is OPTIONAL. 397 When used with a JWK, the "kid" value MAY be used to match a JWK 398 "kid" parameter value. 400 4.1.8. "typ" (Type) Header Parameter 402 The "typ" (type) header parameter is used to declare the type of this 403 object. The type value "JWS" MAY be used to indicate that this 404 object is a JWS. The "typ" value is a case sensitive string. This 405 header parameter is OPTIONAL. 407 MIME Media Type [RFC2046] values MAY be used as "typ" values. 409 "typ" values SHOULD either be registered in the IANA JSON Web 410 Signature and Encryption Type Values registry Section 7.2 or be a URI 411 that contains a Collision Resistant Namespace. 413 4.1.9. "cty" (Content Type) Header Parameter 415 The "cty" (content type) header parameter is used to declare the type 416 of the secured content (the Payload). The "cty" value is a case 417 sensitive string. This header parameter is OPTIONAL. 419 The values used for the "cty" header parameter come from the same 420 value space as the "typ" header parameter, with the same rules 421 applying. 423 4.2. Public Header Parameter Names 425 Additional header parameter names can be defined by those using JWSs. 426 However, in order to prevent collisions, any new header parameter 427 name SHOULD either be registered in the IANA JSON Web Signature and 428 Encryption Header Parameters registry Section 7.1 or be a URI that 429 contains a Collision Resistant Namespace. In each case, the definer 430 of the name or value needs to take reasonable precautions to make 431 sure they are in control of the part of the namespace they use to 432 define the header parameter name. 434 New header parameters should be introduced sparingly, as they can 435 result in non-interoperable JWSs. 437 4.3. Private Header Parameter Names 439 A producer and consumer of a JWS may agree to any header parameter 440 name that is not a Reserved Name Section 4.1 or a Public Name 441 Section 4.2. Unlike Public Names, these private names are subject to 442 collision and should be used with caution. 444 5. Rules for Creating and Validating a JWS 446 To create a JWS, one MUST perform these steps. The order of the 447 steps is not significant in cases where there are no dependencies 448 between the inputs and outputs of the steps. 450 1. Create the content to be used as the JWS Payload. 452 2. Base64url encode the bytes of the JWS Payload. This encoding 453 becomes the Encoded JWS Payload. 455 3. Create a JWS Header containing the desired set of header 456 parameters. Note that white space is explicitly allowed in the 457 representation and no canonicalization need be performed before 458 encoding. 460 4. Base64url encode the bytes of the UTF-8 representation of the JWS 461 Header to create the Encoded JWS Header. 463 5. Compute the JWS Signature in the manner defined for the 464 particular algorithm being used. The JWS Secured Input is always 465 the concatenation of the Encoded JWS Header, a period ('.') 466 character, and the Encoded JWS Payload. The "alg" (algorithm) 467 header parameter MUST be present in the JSON Header, with the 468 algorithm value accurately representing the algorithm used to 469 construct the JWS Signature. 471 6. Base64url encode the representation of the JWS Signature to 472 create the Encoded JWS Signature. 474 7. The three encoded parts, taken together, are the result. The 475 Compact Serialization of this result is the concatenation of the 476 Encoded JWS Header, the Encoded JWS Payload, and the Encoded JWS 477 Signature in that order, with the three strings being separated 478 by period ('.') characters. 480 When validating a JWS, the following steps MUST be taken. The order 481 of the steps is not significant in cases where there are no 482 dependencies between the inputs and outputs of the steps. If any of 483 the listed steps fails, then the JWS MUST be rejected. 485 1. Parse the three parts of the input (which are separated by period 486 characters when using the JWS Compact Serialization) into the 487 Encoded JWS Header, the Encoded JWS Payload, and the Encoded JWS 488 Signature. 490 2. The Encoded JWS Header MUST be successfully base64url decoded 491 following the restriction given in this specification that no 492 padding characters have been used. 494 3. The resulting JWS Header MUST be completely valid JSON syntax 495 conforming to RFC 4627 [RFC4627]. 497 4. The resulting JWS Header MUST be validated to only include 498 parameters and values whose syntax and semantics are both 499 understood and supported. 501 5. The Encoded JWS Payload MUST be successfully base64url decoded 502 following the restriction given in this specification that no 503 padding characters have been used. 505 6. The Encoded JWS Signature MUST be successfully base64url decoded 506 following the restriction given in this specification that no 507 padding characters have been used. 509 7. The JWS Signature MUST be successfully validated against the JWS 510 Secured Input (the concatenation of the Encoded JWS Header, a 511 period ('.') character, and the Encoded JWS Payload) in the 512 manner defined for the algorithm being used, which MUST be 513 accurately represented by the value of the "alg" (algorithm) 514 header parameter, which MUST be present. 516 Processing a JWS inevitably requires comparing known strings to 517 values in the header. For example, in checking what the algorithm 518 is, the Unicode string encoding "alg" will be checked against the 519 member names in the JWS Header to see if there is a matching header 520 parameter name. A similar process occurs when determining if the 521 value of the "alg" header parameter represents a supported algorithm. 523 Comparisons between JSON strings and other Unicode strings MUST be 524 performed as specified below: 526 1. Remove any JSON applied escaping to produce an array of Unicode 527 code points. 529 2. Unicode Normalization [USA15] MUST NOT be applied at any point to 530 either the JSON string or to the string it is to be compared 531 against. 533 3. Comparisons between the two strings MUST be performed as a 534 Unicode code point to code point equality comparison. 536 6. Securing JWSs with Cryptographic Algorithms 538 JWS uses cryptographic algorithms to digitally sign or MAC the JWS 539 Header and the JWS Payload. The JSON Web Algorithms (JWA) [JWA] 540 specification describes a set of cryptographic algorithms and 541 identifiers to be used with this specification. Specifically, 542 Section 3.1 specifies a set of "alg" (algorithm) header parameter 543 values intended for use this specification. It also describes the 544 semantics and operations that are specific to these algorithms and 545 algorithm families. 547 Public keys employed for digital signing can be identified using the 548 Header Parameter methods described in Section 4.1 or can be 549 distributed using methods that are outside the scope of this 550 specification. 552 7. IANA Considerations 554 The following registration procedure is used for all the registries 555 established by this specification. 557 Values are registered with a Specification Required [RFC5226] after a 558 two week review period on the [TBD]@ietf.org mailing list, on the 559 advice of one or more Designated Experts. However, to allow for the 560 allocation of values prior to publication, the Designated Expert(s) 561 may approve registration once they are satisfied that such a 562 specification will be published. 564 Registration requests must be sent to the [TBD]@ietf.org mailing list 565 for review and comment, with an appropriate subject (e.g., "Request 566 for access token type: example"). [[ Note to RFC-EDITOR: The name of 567 the mailing list should be determined in consultation with the IESG 568 and IANA. Suggested name: jose-reg-review. ]] 570 Within the review period, the Designated Expert(s) will either 571 approve or deny the registration request, communicating this decision 572 to the review list and IANA. Denials should include an explanation 573 and, if applicable, suggestions as to how to make the request 574 successful. 576 IANA must only accept registry updates from the Designated Expert(s), 577 and should direct all requests for registration to the review mailing 578 list. 580 7.1. JSON Web Signature and Encryption Header Parameters Registry 582 This specification establishes the IANA JSON Web Signature and 583 Encryption Header Parameters registry for reserved JWS and JWE header 584 parameter names. The registry records the reserved header parameter 585 name and a reference to the specification that defines it. The same 586 Header Parameter Name may be registered multiple times, provided that 587 the parameter usage is compatible between the specifications. 589 7.1.1. Registration Template 591 Header Parameter Name: 592 The name requested (e.g., "example"). This name is case 593 sensitive. Names that match other registered names in a case 594 insensitive manner SHOULD NOT be accepted. 596 Change Controller: 597 For standards-track RFCs, state "IETF". For others, give the name 598 of the responsible party. Other details (e.g., postal address, 599 e-mail address, home page URI) may also be included. 601 Specification Document(s): 602 Reference to the document that specifies the parameter, preferably 603 including a URI that can be used to retrieve a copy of the 604 document. An indication of the relevant sections may also be 605 included, but is not required. 607 7.1.2. Initial Registry Contents 609 This specification registers the Header Parameter Names defined in 610 Section 4.1 in this registry. 612 o Header Parameter Name: "alg" 614 o Change Controller: IETF 616 o Specification Document(s): Section 4.1.1 of [[ this document ]] 618 o Header Parameter Name: "jku" 620 o Change Controller: IETF 622 o Specification Document(s): Section 4.1.2 of [[ this document ]] 624 o Header Parameter Name: "jwk" 626 o Change Controller: IETF 628 o Specification document(s): Section 4.1.3 of [[ this document ]] 630 o Header Parameter Name: "x5u" 632 o Change Controller: IETF 634 o Specification Document(s): Section 4.1.4 of [[ this document ]] 636 o Header Parameter Name: "x5t" 638 o Change Controller: IETF 640 o Specification Document(s): Section 4.1.5 of [[ this document ]] 641 o Header Parameter Name: "x5c" 643 o Change Controller: IETF 645 o Specification Document(s): Section 4.1.6 of [[ this document ]] 647 o Header Parameter Name: "kid" 649 o Change Controller: IETF 651 o Specification Document(s): Section 4.1.7 of [[ this document ]] 653 o Header Parameter Name: "typ" 655 o Change Controller: IETF 657 o Specification Document(s): Section 4.1.8 of [[ this document ]] 659 o Header Parameter Name: "cty" 661 o Change Controller: IETF 663 o Specification Document(s): Section 4.1.9 of [[ this document ]] 665 7.2. JSON Web Signature and Encryption Type Values Registry 667 This specification establishes the IANA JSON Web Signature and 668 Encryption Type Values registry for values of the JWS and JWE "typ" 669 (type) header parameter. It is RECOMMENDED that all registered "typ" 670 values also include a MIME Media Type [RFC2046] value that the 671 registered value is a short name for. The registry records the "typ" 672 value, the MIME type value that it is an abbreviation for (if any), 673 and a reference to the specification that defines it. 675 MIME Media Type [RFC2046] values MUST NOT be directly registered as 676 new "typ" values; rather, new "typ" values MAY be registered as short 677 names for MIME types. 679 7.2.1. Registration Template 681 "typ" Header Parameter Value: 682 The name requested (e.g., "example"). This name is case 683 sensitive. Names that match other registered names in a case 684 insensitive manner SHOULD NOT be accepted. 686 Abbreviation for MIME Type: 687 The MIME type that this name is an abbreviation for (e.g., 688 "application/example"). 690 Change Controller: 691 For standards-track RFCs, state "IETF". For others, give the name 692 of the responsible party. Other details (e.g., postal address, 693 e-mail address, home page URI) may also be included. 695 Specification Document(s): 696 Reference to the document that specifies the parameter, preferably 697 including a URI that can be used to retrieve a copy of the 698 document. An indication of the relevant sections may also be 699 included, but is not required. 701 7.2.2. Initial Registry Contents 703 This specification registers the "JWS" type value in this registry: 705 o "typ" Header Parameter Value: "JWS" 707 o Abbreviation for MIME type: application/jws 709 o Change Controller: IETF 711 o Specification Document(s): Section 4.1.8 of [[ this document ]] 713 7.3. Media Type Registration 715 7.3.1. Registry Contents 717 This specification registers the "application/jws" Media Type 718 [RFC2046] in the MIME Media Type registry [RFC4288] to indicate that 719 the content is a JWS using the Compact Serialization. 721 o Type name: application 723 o Subtype name: jws 725 o Required parameters: n/a 727 o Optional parameters: n/a 729 o Encoding considerations: JWS values are encoded as a series of 730 base64url encoded values (some of which may be the empty string) 731 separated by period ('.') characters 733 o Security considerations: See the Security Considerations section 734 of this document 736 o Interoperability considerations: n/a 738 o Published specification: [[ this document ]] 740 o Applications that use this media type: OpenID Connect, Mozilla 741 Browser ID, Salesforce, Google, numerous others that use signed 742 JWTs 744 o Additional information: Magic number(s): n/a, File extension(s): 745 n/a, Macintosh file type code(s): n/a 747 o Person & email address to contact for further information: Michael 748 B. Jones, mbj@microsoft.com 750 o Intended usage: COMMON 752 o Restrictions on usage: none 754 o Author: Michael B. Jones, mbj@microsoft.com 756 o Change Controller: IETF 758 8. Security Considerations 760 8.1. Cryptographic Security Considerations 762 All of the security issues faced by any cryptographic application 763 must be faced by a JWS/JWE/JWK agent. Among these issues are 764 protecting the user's private key, preventing various attacks, and 765 helping the user avoid mistakes such as inadvertently encrypting a 766 message for the wrong recipient. The entire list of security 767 considerations is beyond the scope of this document, but some 768 significant concerns are listed here. 770 All the security considerations in XML DSIG 2.0 771 [W3C.CR-xmldsig-core2-20120124], also apply to this specification, 772 other than those that are XML specific. Likewise, many of the best 773 practices documented in XML Signature Best Practices 774 [W3C.WD-xmldsig-bestpractices-20110809] also apply to this 775 specification, other than those that are XML specific. 777 Keys are only as strong as the amount of entropy used to generate 778 them. A minimum of 128 bits of entropy should be used for all keys, 779 and depending upon the application context, more may be required. In 780 particular, it may be difficult to generate sufficiently random 781 values in some browsers and application environments. 783 When utilizing TLS to retrieve information, the authority providing 784 the resource MUST be authenticated and the information retrieved MUST 785 be free from modification. 787 When cryptographic algorithms are implemented in such a way that 788 successful operations take a different amount of time than 789 unsuccessful operations, attackers may be able to use the time 790 difference to obtain information about the keys employed. Therefore, 791 such timing differences must be avoided. 793 A SHA-1 hash is used when computing "x5t" (x.509 certificate 794 thumbprint) values, for compatibility reasons. Should an effective 795 means of producing SHA-1 hash collisions be developed, and should an 796 attacker wish to interfere with the use of a known certificate on a 797 given system, this could be accomplished by creating another 798 certificate whose SHA-1 hash value is the same and adding it to the 799 certificate store used by the intended victim. A prerequisite to 800 this attack succeeding is the attacker having write access to the 801 intended victim's certificate store. 803 If, in the future, certificate thumbprints need to be computed using 804 hash functions other than SHA-1, it is suggested that additional 805 related header parameters be defined for that purpose. For example, 806 it is suggested that a new "x5t#S256" (X.509 Certificate Thumbprint 807 using SHA-256) header parameter could be defined and used. 809 8.2. JSON Security Considerations 811 Strict JSON validation is a security requirement. If malformed JSON 812 is received, then the intent of the sender is impossible to reliably 813 discern. Ambiguous and potentially exploitable situations could 814 arise if the JSON parser used does not reject malformed JSON syntax. 816 Section 2.2 of the JavaScript Object Notation (JSON) specification 817 [RFC4627] states "The names within an object SHOULD be unique", 818 whereas this specification states that "Header Parameter Names within 819 this object MUST be unique; JWSs with duplicate Header Parameter 820 Names MUST be rejected". Thus, this specification requires that the 821 Section 2.2 "SHOULD" be treated as a "MUST". Ambiguous and 822 potentially exploitable situations could arise if the JSON parser 823 used does not enforce the uniqueness of member names. 825 8.3. Unicode Comparison Security Considerations 827 Header parameter names and algorithm names are Unicode strings. For 828 security reasons, the representations of these names must be compared 829 verbatim after performing any escape processing (as per RFC 4627 830 [RFC4627], Section 2.5). This means, for instance, that these JSON 831 strings must compare as being equal ("sig", "\u0073ig"), whereas 832 these must all compare as being not equal to the first set or to each 833 other ("SIG", "Sig", "si\u0047"). 835 JSON strings MAY contain characters outside the Unicode Basic 836 Multilingual Plane. For instance, the G clef character (U+1D11E) may 837 be represented in a JSON string as "\uD834\uDD1E". Ideally, JWS 838 implementations SHOULD ensure that characters outside the Basic 839 Multilingual Plane are preserved and compared correctly; 840 alternatively, if this is not possible due to these characters 841 exercising limitations present in the underlying JSON implementation, 842 then input containing them MUST be rejected. 844 9. Open Issues 846 [[ to be removed by the RFC editor before publication as an RFC ]] 848 The following items remain to be considered or done in this draft: 850 o Should we define an optional nonce and/or timestamp header 851 parameter? (Use of a nonce is an effective countermeasure to some 852 kinds of attacks.) 854 o Some have objected to the language "Implementations MUST 855 understand the entire contents of the header; otherwise, the JWS 856 MUST be rejected" in this spec and the related language in the 857 JWE, JWK, and JWT specs. Others believe that this is essential in 858 a security specification. 860 o Finish the Security Considerations section. 862 10. References 864 10.1. Normative References 866 [ITU.X690.1994] 867 International Telecommunications Union, "Information 868 Technology - ASN.1 encoding rules: Specification of Basic 869 Encoding Rules (BER), Canonical Encoding Rules (CER) and 870 Distinguished Encoding Rules (DER)", ITU-T Recommendation 871 X.690, 1994. 873 [JWA] Jones, M., "JSON Web Algorithms (JWA)", July 2012. 875 [JWK] Jones, M., "JSON Web Key (JWK)", July 2012. 877 [RFC1421] Linn, J., "Privacy Enhancement for Internet Electronic 878 Mail: Part I: Message Encryption and Authentication 879 Procedures", RFC 1421, February 1993. 881 [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail 882 Extensions (MIME) Part Two: Media Types", RFC 2046, 883 November 1996. 885 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 886 Requirement Levels", BCP 14, RFC 2119, March 1997. 888 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. 890 [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 891 10646", STD 63, RFC 3629, November 2003. 893 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 894 Resource Identifier (URI): Generic Syntax", STD 66, 895 RFC 3986, January 2005. 897 [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and 898 Registration Procedures", BCP 13, RFC 4288, December 2005. 900 [RFC4627] Crockford, D., "The application/json Media Type for 901 JavaScript Object Notation (JSON)", RFC 4627, July 2006. 903 [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data 904 Encodings", RFC 4648, October 2006. 906 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 907 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 908 May 2008. 910 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security 911 (TLS) Protocol Version 1.2", RFC 5246, August 2008. 913 [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., 914 Housley, R., and W. Polk, "Internet X.509 Public Key 915 Infrastructure Certificate and Certificate Revocation List 916 (CRL) Profile", RFC 5280, May 2008. 918 [USA15] Davis, M., Whistler, K., and M. Duerst, "Unicode 919 Normalization Forms", Unicode Standard Annex 15, 09 2009. 921 [USASCII] American National Standards Institute, "Coded Character 922 Set -- 7-bit American Standard Code for Information 923 Interchange", ANSI X3.4, 1986. 925 [W3C.WD-xmldsig-bestpractices-20110809] 926 Datta, P. and F. Hirsch, "XML Signature Best Practices", 927 World Wide Web Consortium WD WD-xmldsig-bestpractices- 928 20110809, August 2011, . 931 10.2. Informative References 933 [CanvasApp] 934 Facebook, "Canvas Applications", 2010. 936 [JSS] Bradley, J. and N. Sakimura (editor), "JSON Simple Sign", 937 September 2010. 939 [JWE] Jones, M., Rescorla, E., and J. Hildebrand, "JSON Web 940 Encryption (JWE)", July 2012. 942 [JWS-JS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web 943 Signature JSON Serialization (JWS-JS)", July 2012. 945 [JWT] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token 946 (JWT)", July 2012. 948 [MagicSignatures] 949 Panzer (editor), J., Laurie, B., and D. Balfanz, "Magic 950 Signatures", January 2011. 952 [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally 953 Unique IDentifier (UUID) URN Namespace", RFC 4122, 954 July 2005. 956 [W3C.CR-xmldsig-core2-20120124] 957 Solo, D., Datta, P., Hirsch, F., Cantor, S., Reagle, J., 958 Roessler, T., Eastlake, D., and K. Yiu, "XML Signature 959 Syntax and Processing Version 2.0", World Wide Web 960 Consortium CR CR-xmldsig-core2-20120124, January 2012, 961 . 963 Appendix A. JWS Examples 965 This section provides several examples of JWSs. While these examples 966 all represent JSON Web Tokens (JWTs) [JWT], the payload can be any 967 base64url encoded content. 969 A.1. JWS using HMAC SHA-256 971 A.1.1. Encoding 973 The following example JWS Header declares that the data structure is 974 a JSON Web Token (JWT) [JWT] and the JWS Secured Input is secured 975 using the HMAC SHA-256 algorithm. 977 {"typ":"JWT", 978 "alg":"HS256"} 980 The following byte array contains the UTF-8 representation of the JWS 981 Header: 983 [123, 34, 116, 121, 112, 34, 58, 34, 74, 87, 84, 34, 44, 13, 10, 32, 984 34, 97, 108, 103, 34, 58, 34, 72, 83, 50, 53, 54, 34, 125] 986 Base64url encoding these bytes yields this Encoded JWS Header value: 988 eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9 990 The JWS Payload used in this example is the bytes of the UTF-8 991 representation of the JSON object below. (Note that the payload can 992 be any base64url encoded sequence of bytes, and need not be a 993 base64url encoded JSON object.) 995 {"iss":"joe", 996 "exp":1300819380, 997 "http://example.com/is_root":true} 999 The following byte array, which is the UTF-8 representation of the 1000 JSON object above, is the JWS Payload: 1002 [123, 34, 105, 115, 115, 34, 58, 34, 106, 111, 101, 34, 44, 13, 10, 1003 32, 34, 101, 120, 112, 34, 58, 49, 51, 48, 48, 56, 49, 57, 51, 56, 1004 48, 44, 13, 10, 32, 34, 104, 116, 116, 112, 58, 47, 47, 101, 120, 97, 1005 109, 112, 108, 101, 46, 99, 111, 109, 47, 105, 115, 95, 114, 111, 1006 111, 116, 34, 58, 116, 114, 117, 101, 125] 1008 Base64url encoding the above yields the Encoded JWS Payload value 1009 (with line breaks for display purposes only): 1011 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 1012 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1014 Concatenating the Encoded JWS Header, a period character, and the 1015 Encoded JWS Payload yields this JWS Secured Input value (with line 1016 breaks for display purposes only): 1018 eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9 1019 . 1020 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 1021 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1023 The ASCII representation of the JWS Secured Input is the following 1024 byte array: 1026 [101, 121, 74, 48, 101, 88, 65, 105, 79, 105, 74, 75, 86, 49, 81, 1027 105, 76, 65, 48, 75, 73, 67, 74, 104, 98, 71, 99, 105, 79, 105, 74, 1028 73, 85, 122, 73, 49, 78, 105, 74, 57, 46, 101, 121, 74, 112, 99, 51, 1029 77, 105, 79, 105, 74, 113, 98, 50, 85, 105, 76, 65, 48, 75, 73, 67, 1030 74, 108, 101, 72, 65, 105, 79, 106, 69, 122, 77, 68, 65, 52, 77, 84, 1031 107, 122, 79, 68, 65, 115, 68, 81, 111, 103, 73, 109, 104, 48, 100, 1032 72, 65, 54, 76, 121, 57, 108, 101, 71, 70, 116, 99, 71, 120, 108, 76, 1033 109, 78, 118, 98, 83, 57, 112, 99, 49, 57, 121, 98, 50, 57, 48, 73, 1034 106, 112, 48, 99, 110, 86, 108, 102, 81] 1036 HMACs are generated using keys. This example uses the key 1037 represented by the following byte array: 1039 [3, 35, 53, 75, 43, 15, 165, 188, 131, 126, 6, 101, 119, 123, 166, 1040 143, 90, 179, 40, 230, 240, 84, 201, 40, 169, 15, 132, 178, 210, 80, 1041 46, 191, 211, 251, 90, 146, 210, 6, 71, 239, 150, 138, 180, 195, 119, 1042 98, 61, 34, 61, 46, 33, 114, 5, 46, 79, 8, 192, 205, 154, 245, 103, 1043 208, 128, 163] 1045 Running the HMAC SHA-256 algorithm on the bytes of the ASCII 1046 representation of the JWS Secured Input with this key yields the 1047 following byte array: 1049 [116, 24, 223, 180, 151, 153, 224, 37, 79, 250, 96, 125, 216, 173, 1050 187, 186, 22, 212, 37, 77, 105, 214, 191, 240, 91, 88, 5, 88, 83, 1051 132, 141, 121] 1053 Base64url encoding the above HMAC output yields the Encoded JWS 1054 Signature value: 1056 dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk 1058 A.1.2. Decoding 1060 Decoding the JWS requires base64url decoding the Encoded JWS Header, 1061 Encoded JWS Payload, and Encoded JWS Signature to produce the JWS 1062 Header, JWS Payload, and JWS Signature byte arrays. The byte array 1063 containing the UTF-8 representation of the JWS Header is decoded into 1064 the JWS Header string. 1066 A.1.3. Validating 1068 Next we validate the decoded results. Since the "alg" parameter in 1069 the header is "HS256", we validate the HMAC SHA-256 value contained 1070 in the JWS Signature. If any of the validation steps fail, the JWS 1071 MUST be rejected. 1073 First, we validate that the JWS Header string is legal JSON. 1075 To validate the HMAC value, we repeat the previous process of using 1076 the correct key and the ASCII representation of the JWS Secured Input 1077 as input to the HMAC SHA-256 function and then taking the output and 1078 determining if it matches the JWS Signature. If it matches exactly, 1079 the HMAC has been validated. 1081 A.2. JWS using RSA SHA-256 1083 A.2.1. Encoding 1085 The JWS Header in this example is different from the previous example 1086 in two ways: First, because a different algorithm is being used, the 1087 "alg" value is different. Second, for illustration purposes only, 1088 the optional "typ" parameter is not used. (This difference is not 1089 related to the algorithm employed.) The JWS Header used is: 1091 {"alg":"RS256"} 1093 The following byte array contains the UTF-8 representation of the JWS 1094 Header: 1096 [123, 34, 97, 108, 103, 34, 58, 34, 82, 83, 50, 53, 54, 34, 125] 1098 Base64url encoding these bytes yields this Encoded JWS Header value: 1100 eyJhbGciOiJSUzI1NiJ9 1102 The JWS Payload used in this example, which follows, is the same as 1103 in the previous example. Since the Encoded JWS Payload will 1104 therefore be the same, its computation is not repeated here. 1106 {"iss":"joe", 1107 "exp":1300819380, 1108 "http://example.com/is_root":true} 1110 Concatenating the Encoded JWS Header, a period character, and the 1111 Encoded JWS Payload yields this JWS Secured Input value (with line 1112 breaks for display purposes only): 1114 eyJhbGciOiJSUzI1NiJ9 1115 . 1116 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 1117 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1119 The ASCII representation of the JWS Secured Input is the following 1120 byte array: 1122 [101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 83, 85, 122, 73, 1123 49, 78, 105, 74, 57, 46, 101, 121, 74, 112, 99, 51, 77, 105, 79, 105, 1124 74, 113, 98, 50, 85, 105, 76, 65, 48, 75, 73, 67, 74, 108, 101, 72, 1125 65, 105, 79, 106, 69, 122, 77, 68, 65, 52, 77, 84, 107, 122, 79, 68, 1126 65, 115, 68, 81, 111, 103, 73, 109, 104, 48, 100, 72, 65, 54, 76, 1127 121, 57, 108, 101, 71, 70, 116, 99, 71, 120, 108, 76, 109, 78, 118, 1128 98, 83, 57, 112, 99, 49, 57, 121, 98, 50, 57, 48, 73, 106, 112, 48, 1129 99, 110, 86, 108, 102, 81] 1131 The RSA key consists of a public part (Modulus, Exponent), and a 1132 Private Exponent. The values of the RSA key used in this example, 1133 presented as the byte arrays representing big endian integers are: 1135 +-----------+-------------------------------------------------------+ 1136 | Parameter | Value | 1137 | Name | | 1138 +-----------+-------------------------------------------------------+ 1139 | Modulus | [161, 248, 22, 10, 226, 227, 201, 180, 101, 206, 141, | 1140 | | 45, 101, 98, 99, 54, 43, 146, 125, 190, 41, 225, 240, | 1141 | | 36, 119, 252, 22, 37, 204, 144, 161, 54, 227, 139, | 1142 | | 217, 52, 151, 197, 182, 234, 99, 221, 119, 17, 230, | 1143 | | 124, 116, 41, 249, 86, 176, 251, 138, 143, 8, 154, | 1144 | | 220, 75, 105, 137, 60, 193, 51, 63, 83, 237, 208, 25, | 1145 | | 184, 119, 132, 37, 47, 236, 145, 79, 228, 133, 119, | 1146 | | 105, 89, 75, 234, 66, 128, 211, 44, 15, 85, 191, 98, | 1147 | | 148, 79, 19, 3, 150, 188, 110, 155, 223, 110, 189, | 1148 | | 210, 189, 163, 103, 142, 236, 160, 198, 104, 247, 1, | 1149 | | 179, 141, 191, 251, 56, 200, 52, 44, 226, 254, 109, | 1150 | | 39, 250, 222, 74, 90, 72, 116, 151, 157, 212, 185, | 1151 | | 207, 154, 222, 196, 199, 91, 5, 133, 44, 44, 15, 94, | 1152 | | 248, 165, 193, 117, 3, 146, 249, 68, 232, 237, 100, | 1153 | | 193, 16, 198, 182, 71, 96, 154, 164, 120, 58, 235, | 1154 | | 156, 108, 154, 215, 85, 49, 48, 80, 99, 139, 131, | 1155 | | 102, 92, 111, 111, 122, 130, 163, 150, 112, 42, 31, | 1156 | | 100, 27, 130, 211, 235, 242, 57, 34, 25, 73, 31, 182, | 1157 | | 134, 135, 44, 87, 22, 245, 10, 248, 53, 141, 154, | 1158 | | 139, 157, 23, 195, 64, 114, 143, 127, 135, 216, 154, | 1159 | | 24, 216, 252, 171, 103, 173, 132, 89, 12, 46, 207, | 1160 | | 117, 147, 57, 54, 60, 7, 3, 77, 111, 96, 111, 158, | 1161 | | 33, 224, 84, 86, 202, 229, 233, 161] | 1162 | Exponent | [1, 0, 1] | 1163 | Private | [18, 174, 113, 164, 105, 205, 10, 43, 195, 126, 82, | 1164 | Exponent | 108, 69, 0, 87, 31, 29, 97, 117, 29, 100, 233, 73, | 1165 | | 112, 123, 98, 89, 15, 157, 11, 165, 124, 150, 60, 64, | 1166 | | 30, 63, 207, 47, 44, 211, 189, 236, 136, 229, 3, 191, | 1167 | | 198, 67, 155, 11, 40, 200, 47, 125, 55, 151, 103, 31, | 1168 | | 82, 19, 238, 216, 193, 90, 37, 216, 213, 206, 160, 2, | 1169 | | 94, 227, 171, 46, 139, 127, 121, 33, 111, 198, 59, | 1170 | | 234, 86, 39, 83, 180, 6, 68, 198, 161, 81, 39, 217, | 1171 | | 178, 149, 69, 64, 160, 187, 225, 163, 5, 86, 152, 45, | 1172 | | 78, 159, 222, 95, 100, 37, 241, 77, 75, 113, 52, 65, | 1173 | | 181, 93, 199, 59, 155, 74, 237, 204, 146, 172, 227, | 1174 | | 146, 126, 55, 245, 125, 12, 253, 94, 117, 129, 250, | 1175 | | 81, 44, 143, 73, 97, 169, 235, 11, 128, 248, 168, 7, | 1176 | | 70, 114, 138, 85, 255, 70, 71, 31, 52, 37, 6, 59, | 1177 | | 157, 83, 100, 47, 94, 222, 30, 132, 214, 19, 8, 26, | 1178 | | 250, 92, 34, 208, 81, 40, 91, 214, 59, 148, 59, 86, | 1179 | | 93, 137, 138, 5, 104, 84, 19, 229, 60, 60, 108, 101, | 1180 | | 37, 255, 31, 227, 78, 61, 220, 112, 240, 213, 100, | 1181 | | 80, 253, 164, 139, 161, 46, 16, 78, 157, 235, 159, | 1182 | | 184, 24, 129, 225, 196, 189, 242, 93, 146, 71, 244, | 1183 | | 80, 200, 101, 146, 121, 104, 231, 115, 52, 244, 65, | 1184 | | 79, 117, 167, 80, 225, 57, 84, 110, 58, 138, 115, | 1185 | | 157] | 1186 +-----------+-------------------------------------------------------+ 1188 The RSA private key (Modulus, Private Exponent) is then passed to the 1189 RSA signing function, which also takes the hash type, SHA-256, and 1190 the bytes of the ASCII representation of the JWS Secured Input as 1191 inputs. The result of the digital signature is a byte array, which 1192 represents a big endian integer. In this example, it is: 1194 [112, 46, 33, 137, 67, 232, 143, 209, 30, 181, 216, 45, 191, 120, 69, 1195 243, 65, 6, 174, 27, 129, 255, 247, 115, 17, 22, 173, 209, 113, 125, 1196 131, 101, 109, 66, 10, 253, 60, 150, 238, 221, 115, 162, 102, 62, 81, 1197 102, 104, 123, 0, 11, 135, 34, 110, 1, 135, 237, 16, 115, 249, 69, 1198 229, 130, 173, 252, 239, 22, 216, 90, 121, 142, 232, 198, 109, 219, 1199 61, 184, 151, 91, 23, 208, 148, 2, 190, 237, 213, 217, 217, 112, 7, 1200 16, 141, 178, 129, 96, 213, 248, 4, 12, 167, 68, 87, 98, 184, 31, 1201 190, 127, 249, 217, 46, 10, 231, 111, 36, 242, 91, 51, 187, 230, 244, 1202 74, 230, 30, 177, 4, 10, 203, 32, 4, 77, 62, 249, 18, 142, 212, 1, 1203 48, 121, 91, 212, 189, 59, 65, 238, 202, 208, 102, 171, 101, 25, 129, 1204 253, 228, 141, 247, 127, 55, 45, 195, 139, 159, 175, 221, 59, 239, 1205 177, 139, 93, 163, 204, 60, 46, 176, 47, 158, 58, 65, 214, 18, 202, 1206 173, 21, 145, 18, 115, 160, 95, 35, 185, 232, 56, 250, 175, 132, 157, 1207 105, 132, 41, 239, 90, 30, 136, 121, 130, 54, 195, 212, 14, 96, 69, 1208 34, 165, 68, 200, 242, 122, 122, 45, 184, 6, 99, 209, 108, 247, 202, 1209 234, 86, 222, 64, 92, 178, 33, 90, 69, 178, 194, 85, 102, 181, 90, 1210 193, 167, 72, 160, 112, 223, 200, 163, 42, 70, 149, 67, 208, 25, 238, 1211 251, 71] 1213 Base64url encoding the digital signature produces this value for the 1214 Encoded JWS Signature (with line breaks for display purposes only): 1216 cC4hiUPoj9Eetdgtv3hF80EGrhuB__dzERat0XF9g2VtQgr9PJbu3XOiZj5RZmh7 1217 AAuHIm4Bh-0Qc_lF5YKt_O8W2Fp5jujGbds9uJdbF9CUAr7t1dnZcAcQjbKBYNX4 1218 BAynRFdiuB--f_nZLgrnbyTyWzO75vRK5h6xBArLIARNPvkSjtQBMHlb1L07Qe7K 1219 0GarZRmB_eSN9383LcOLn6_dO--xi12jzDwusC-eOkHWEsqtFZESc6BfI7noOPqv 1220 hJ1phCnvWh6IeYI2w9QOYEUipUTI8np6LbgGY9Fs98rqVt5AXLIhWkWywlVmtVrB 1221 p0igcN_IoypGlUPQGe77Rw 1223 A.2.2. Decoding 1225 Decoding the JWS requires base64url decoding the Encoded JWS Header, 1226 Encoded JWS Payload, and Encoded JWS Signature to produce the JWS 1227 Header, JWS Payload, and JWS Signature byte arrays. The byte array 1228 containing the UTF-8 representation of the JWS Header is decoded into 1229 the JWS Header string. 1231 A.2.3. Validating 1233 Since the "alg" parameter in the header is "RS256", we validate the 1234 RSA SHA-256 digital signature contained in the JWS Signature. If any 1235 of the validation steps fail, the JWS MUST be rejected. 1237 First, we validate that the JWS Header string is legal JSON. 1239 Validating the JWS Signature is a little different from the previous 1240 example. First, we base64url decode the Encoded JWS Signature to 1241 produce a digital signature S to check. We then pass (n, e), S and 1242 the bytes of the ASCII representation of the JWS Secured Input to an 1243 RSA signature verifier that has been configured to use the SHA-256 1244 hash function. 1246 A.3. JWS using ECDSA P-256 SHA-256 1248 A.3.1. Encoding 1250 The JWS Header for this example differs from the previous example 1251 because a different algorithm is being used. The JWS Header used is: 1253 {"alg":"ES256"} 1255 The following byte array contains the UTF-8 representation of the JWS 1256 Header: 1258 [123, 34, 97, 108, 103, 34, 58, 34, 69, 83, 50, 53, 54, 34, 125] 1259 Base64url encoding these bytes yields this Encoded JWS Header value: 1261 eyJhbGciOiJFUzI1NiJ9 1263 The JWS Payload used in this example, which follows, is the same as 1264 in the previous examples. Since the Encoded JWS Payload will 1265 therefore be the same, its computation is not repeated here. 1267 {"iss":"joe", 1268 "exp":1300819380, 1269 "http://example.com/is_root":true} 1271 Concatenating the Encoded JWS Header, a period character, and the 1272 Encoded JWS Payload yields this JWS Secured Input value (with line 1273 breaks for display purposes only): 1275 eyJhbGciOiJFUzI1NiJ9 1276 . 1277 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 1278 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1280 The ASCII representation of the JWS Secured Input is the following 1281 byte array: 1283 [101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 70, 85, 122, 73, 1284 49, 78, 105, 74, 57, 46, 101, 121, 74, 112, 99, 51, 77, 105, 79, 105, 1285 74, 113, 98, 50, 85, 105, 76, 65, 48, 75, 73, 67, 74, 108, 101, 72, 1286 65, 105, 79, 106, 69, 122, 77, 68, 65, 52, 77, 84, 107, 122, 79, 68, 1287 65, 115, 68, 81, 111, 103, 73, 109, 104, 48, 100, 72, 65, 54, 76, 1288 121, 57, 108, 101, 71, 70, 116, 99, 71, 120, 108, 76, 109, 78, 118, 1289 98, 83, 57, 112, 99, 49, 57, 121, 98, 50, 57, 48, 73, 106, 112, 48, 1290 99, 110, 86, 108, 102, 81] 1292 The ECDSA key consists of a public part, the EC point (x, y), and a 1293 private part d. The values of the ECDSA key used in this example, 1294 presented as the byte arrays representing three 256 bit big endian 1295 integers are: 1297 +-----------+-------------------------------------------------------+ 1298 | Parameter | Value | 1299 | Name | | 1300 +-----------+-------------------------------------------------------+ 1301 | x | [127, 205, 206, 39, 112, 246, 196, 93, 65, 131, 203, | 1302 | | 238, 111, 219, 75, 123, 88, 7, 51, 53, 123, 233, 239, | 1303 | | 19, 186, 207, 110, 60, 123, 209, 84, 69] | 1304 | y | [199, 241, 68, 205, 27, 189, 155, 126, 135, 44, 223, | 1305 | | 237, 185, 238, 185, 244, 179, 105, 93, 110, 169, 11, | 1306 | | 36, 173, 138, 70, 35, 40, 133, 136, 229, 173] | 1307 | d | [142, 155, 16, 158, 113, 144, 152, 191, 152, 4, 135, | 1308 | | 223, 31, 93, 119, 233, 203, 41, 96, 110, 190, 210, | 1309 | | 38, 59, 95, 87, 194, 19, 223, 132, 244, 178] | 1310 +-----------+-------------------------------------------------------+ 1312 The ECDSA private part d is then passed to an ECDSA signing function, 1313 which also takes the curve type, P-256, the hash type, SHA-256, and 1314 the bytes of the ASCII representation of the JWS Secured Input as 1315 inputs. The result of the digital signature is the EC point (R, S), 1316 where R and S are unsigned integers. In this example, the R and S 1317 values, given as byte arrays representing big endian integers are: 1319 +--------+----------------------------------------------------------+ 1320 | Result | Value | 1321 | Name | | 1322 +--------+----------------------------------------------------------+ 1323 | R | [14, 209, 33, 83, 121, 99, 108, 72, 60, 47, 127, 21, 88, | 1324 | | 7, 212, 2, 163, 178, 40, 3, 58, 249, 124, 126, 23, 129, | 1325 | | 154, 195, 22, 158, 166, 101] | 1326 | S | [197, 10, 7, 211, 140, 60, 112, 229, 216, 241, 45, 175, | 1327 | | 8, 74, 84, 128, 166, 101, 144, 197, 242, 147, 80, 154, | 1328 | | 143, 63, 127, 138, 131, 163, 84, 213] | 1329 +--------+----------------------------------------------------------+ 1331 Concatenating the S array to the end of the R array and base64url 1332 encoding the result produces this value for the Encoded JWS Signature 1333 (with line breaks for display purposes only): 1335 DtEhU3ljbEg8L38VWAfUAqOyKAM6-Xx-F4GawxaepmXFCgfTjDxw5djxLa8ISlSA 1336 pmWQxfKTUJqPP3-Kg6NU1Q 1338 A.3.2. Decoding 1340 Decoding the JWS requires base64url decoding the Encoded JWS Header, 1341 Encoded JWS Payload, and Encoded JWS Signature to produce the JWS 1342 Header, JWS Payload, and JWS Signature byte arrays. The byte array 1343 containing the UTF-8 representation of the JWS Header is decoded into 1344 the JWS Header string. 1346 A.3.3. Validating 1348 Since the "alg" parameter in the header is "ES256", we validate the 1349 ECDSA P-256 SHA-256 digital signature contained in the JWS Signature. 1350 If any of the validation steps fail, the JWS MUST be rejected. 1352 First, we validate that the JWS Header string is legal JSON. 1354 Validating the JWS Signature is a little different from the first 1355 example. First, we base64url decode the Encoded JWS Signature as in 1356 the previous examples but we then need to split the 64 member byte 1357 array that must result into two 32 byte arrays, the first R and the 1358 second S. We then pass (x, y), (R, S) and the bytes of the ASCII 1359 representation of the JWS Secured Input to an ECDSA signature 1360 verifier that has been configured to use the P-256 curve with the 1361 SHA-256 hash function. 1363 As explained in Section 3.4 of the JSON Web Algorithms (JWA) [JWA] 1364 specification, the use of the K value in ECDSA means that we cannot 1365 validate the correctness of the digital signature in the same way we 1366 validated the correctness of the HMAC. Instead, implementations MUST 1367 use an ECDSA validator to validate the digital signature. 1369 A.4. JWS using ECDSA P-521 SHA-512 1371 A.4.1. Encoding 1373 The JWS Header for this example differs from the previous example 1374 because a different ECDSA curve and hash function are used. The JWS 1375 Header used is: 1377 {"alg":"ES512"} 1379 The following byte array contains the UTF-8 representation of the JWS 1380 Header: 1382 [123, 34, 97, 108, 103, 34, 58, 34, 69, 83, 53, 49, 50, 34, 125] 1384 Base64url encoding these bytes yields this Encoded JWS Header value: 1386 eyJhbGciOiJFUzUxMiJ9 1388 The JWS Payload used in this example, is the ASCII string "Payload". 1389 The representation of this string is the byte array: 1391 [80, 97, 121, 108, 111, 97, 100] 1393 Base64url encoding these bytes yields the Encoded JWS Payload value: 1395 UGF5bG9hZA 1397 Concatenating the Encoded JWS Header, a period character, and the 1398 Encoded JWS Payload yields this JWS Secured Input value: 1400 eyJhbGciOiJFUzUxMiJ9.UGF5bG9hZA 1402 The ASCII representation of the JWS Secured Input is the following 1403 byte array: 1405 [101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 70, 85, 122, 85, 1406 120, 77, 105, 74, 57, 46, 85, 71, 70, 53, 98, 71, 57, 104, 90, 65] 1408 The ECDSA key consists of a public part, the EC point (x, y), and a 1409 private part d. The values of the ECDSA key used in this example, 1410 presented as the byte arrays representing three 521 bit big endian 1411 integers are: 1413 +-----------+-------------------------------------------------------+ 1414 | Parameter | Value | 1415 | Name | | 1416 +-----------+-------------------------------------------------------+ 1417 | x | [1, 233, 41, 5, 15, 18, 79, 198, 188, 85, 199, 213, | 1418 | | 57, 51, 101, 223, 157, 239, 74, 176, 194, 44, 178, | 1419 | | 87, 152, 249, 52, 235, 4, 227, 198, 186, 227, 112, | 1420 | | 26, 87, 167, 145, 14, 157, 129, 191, 54, 49, 89, 232, | 1421 | | 235, 203, 21, 93, 99, 73, 244, 189, 182, 204, 248, | 1422 | | 169, 76, 92, 89, 199, 170, 193, 1, 164] | 1423 | y | [0, 52, 166, 68, 14, 55, 103, 80, 210, 55, 31, 209, | 1424 | | 189, 194, 200, 243, 183, 29, 47, 78, 229, 234, 52, | 1425 | | 50, 200, 21, 204, 163, 21, 96, 254, 93, 147, 135, | 1426 | | 236, 119, 75, 85, 131, 134, 48, 229, 203, 191, 90, | 1427 | | 140, 190, 10, 145, 221, 0, 100, 198, 153, 154, 31, | 1428 | | 110, 110, 103, 250, 221, 237, 228, 200, 200, 246] | 1429 | d | [1, 142, 105, 111, 176, 52, 80, 88, 129, 221, 17, 11, | 1430 | | 72, 62, 184, 125, 50, 206, 73, 95, 227, 107, 55, 69, | 1431 | | 237, 242, 216, 202, 228, 240, 242, 83, 159, 70, 21, | 1432 | | 160, 233, 142, 171, 82, 179, 192, 197, 234, 196, 206, | 1433 | | 7, 81, 133, 168, 231, 187, 71, 222, 172, 29, 29, 231, | 1434 | | 123, 204, 246, 97, 53, 230, 61, 130] | 1435 +-----------+-------------------------------------------------------+ 1437 The ECDSA private part d is then passed to an ECDSA signing function, 1438 which also takes the curve type, P-521, the hash type, SHA-512, and 1439 the bytes of the ASCII representation of the JWS Secured Input as 1440 inputs. The result of the digital signature is the EC point (R, S), 1441 where R and S are unsigned integers. In this example, the R and S 1442 values, given as byte arrays representing big endian integers are: 1444 +--------+----------------------------------------------------------+ 1445 | Result | Value | 1446 | Name | | 1447 +--------+----------------------------------------------------------+ 1448 | R | [1, 220, 12, 129, 231, 171, 194, 209, 232, 135, 233, | 1449 | | 117, 247, 105, 122, 210, 26, 125, 192, 1, 217, 21, 82, | 1450 | | 91, 45, 240, 255, 83, 19, 34, 239, 71, 48, 157, 147, | 1451 | | 152, 105, 18, 53, 108, 163, 214, 68, 231, 62, 153, 150, | 1452 | | 106, 194, 164, 246, 72, 143, 138, 24, 50, 129, 223, 133, | 1453 | | 206, 209, 172, 63, 237, 119, 109] | 1454 | S | [0, 111, 6, 105, 44, 5, 41, 208, 128, 61, 152, 40, 92, | 1455 | | 61, 152, 4, 150, 66, 60, 69, 247, 196, 170, 81, 193, | 1456 | | 199, 78, 59, 194, 169, 16, 124, 9, 143, 42, 142, 131, | 1457 | | 48, 206, 238, 34, 175, 83, 203, 220, 159, 3, 107, 155, | 1458 | | 22, 27, 73, 111, 68, 68, 21, 238, 144, 229, 232, 148, | 1459 | | 188, 222, 59, 242, 103] | 1460 +--------+----------------------------------------------------------+ 1462 Concatenating the S array to the end of the R array and base64url 1463 encoding the result produces this value for the Encoded JWS Signature 1464 (with line breaks for display purposes only): 1466 AdwMgeerwtHoh-l192l60hp9wAHZFVJbLfD_UxMi70cwnZOYaRI1bKPWROc-mZZq 1467 wqT2SI-KGDKB34XO0aw_7XdtAG8GaSwFKdCAPZgoXD2YBJZCPEX3xKpRwcdOO8Kp 1468 EHwJjyqOgzDO7iKvU8vcnwNrmxYbSW9ERBXukOXolLzeO_Jn 1470 A.4.2. Decoding 1472 Decoding the JWS requires base64url decoding the Encoded JWS Header, 1473 Encoded JWS Payload, and Encoded JWS Signature to produce the JWS 1474 Header, JWS Payload, and JWS Signature byte arrays. The byte array 1475 containing the UTF-8 representation of the JWS Header is decoded into 1476 the JWS Header string. 1478 A.4.3. Validating 1480 Since the "alg" parameter in the header is "ES512", we validate the 1481 ECDSA P-521 SHA-512 digital signature contained in the JWS Signature. 1482 If any of the validation steps fail, the JWS MUST be rejected. 1484 First, we validate that the JWS Header string is legal JSON. 1486 Validating the JWS Signature is similar to the previous example. 1487 First, we base64url decode the Encoded JWS Signature as in the 1488 previous examples but we then need to split the 132 member byte array 1489 that must result into two 66 byte arrays, the first R and the second 1490 S. We then pass (x, y), (R, S) and the bytes of the ASCII 1491 representation of the JWS Secured Input to an ECDSA signature 1492 verifier that has been configured to use the P-521 curve with the 1493 SHA-512 hash function. 1495 As explained in Section 3.4 of the JSON Web Algorithms (JWA) [JWA] 1496 specification, the use of the K value in ECDSA means that we cannot 1497 validate the correctness of the digital signature in the same way we 1498 validated the correctness of the HMAC. Instead, implementations MUST 1499 use an ECDSA validator to validate the digital signature. 1501 A.5. Example Plaintext JWS 1503 The following example JWS Header declares that the encoded object is 1504 a Plaintext JWS: 1506 {"alg":"none"} 1508 Base64url encoding the bytes of the UTF-8 representation of the JWS 1509 Header yields this Encoded JWS Header: 1511 eyJhbGciOiJub25lIn0 1513 The JWS Payload used in this example, which follows, is the same as 1514 in the previous examples. Since the Encoded JWS Payload will 1515 therefore be the same, its computation is not repeated here. 1517 {"iss":"joe", 1518 "exp":1300819380, 1519 "http://example.com/is_root":true} 1521 The Encoded JWS Signature is the empty string. 1523 Concatenating these parts in the order Header.Payload.Signature with 1524 period characters between the parts yields this complete JWS (with 1525 line breaks for display purposes only): 1527 eyJhbGciOiJub25lIn0 1528 . 1529 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 1530 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1531 . 1533 Appendix B. "x5c" (X.509 Certificate Chain) Example 1535 The string below is an example of a certificate chain that could be 1536 used as the value of an "x5c" (X.509 Certificate Chain) header 1537 parameter, per Section 4.1.6. 1539 -----BEGIN CERTIFICATE----- 1540 MIIE3jCCA8agAwIBAgICAwEwDQYJKoZIhvcNAQEFBQAwYzELMAkGA1UEBhMCVVM 1541 xITAfBgNVBAoTGFRoZSBHbyBEYWRkeSBHcm91cCwgSW5jLjExMC8GA1UECxMoR2 1542 8gRGFkZHkgQ2xhc3MgMiBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eTAeFw0wNjExM 1543 TYwMTU0MzdaFw0yNjExMTYwMTU0MzdaMIHKMQswCQYDVQQGEwJVUzEQMA4GA1UE 1544 CBMHQXJpem9uYTETMBEGA1UEBxMKU2NvdHRzZGFsZTEaMBgGA1UEChMRR29EYWR 1545 keS5jb20sIEluYy4xMzAxBgNVBAsTKmh0dHA6Ly9jZXJ0aWZpY2F0ZXMuZ29kYW 1546 RkeS5jb20vcmVwb3NpdG9yeTEwMC4GA1UEAxMnR28gRGFkZHkgU2VjdXJlIENlc 1547 nRpZmljYXRpb24gQXV0aG9yaXR5MREwDwYDVQQFEwgwNzk2OTI4NzCCASIwDQYJ 1548 KoZIhvcNAQEBBQADggEPADCCAQoCggEBAMQt1RWMnCZM7DI161+4WQFapmGBWTt 1549 wY6vj3D3HKrjJM9N55DrtPDAjhI6zMBS2sofDPZVUBJ7fmd0LJR4h3mUpfjWoqV 1550 Tr9vcyOdQmVZWt7/v+WIbXnvQAjYwqDL1CBM6nPwT27oDyqu9SoWlm2r4arV3aL 1551 GbqGmu75RpRSgAvSMeYddi5Kcju+GZtCpyz8/x4fKL4o/K1w/O5epHBp+YlLpyo 1552 7RJlbmr2EkRTcDCVw5wrWCs9CHRK8r5RsL+H0EwnWGu1NcWdrxcx+AuP7q2BNgW 1553 JCJjPOq8lh8BJ6qf9Z/dFjpfMFDniNoW1fho3/Rb2cRGadDAW/hOUoz+EDU8CAw 1554 EAAaOCATIwggEuMB0GA1UdDgQWBBT9rGEyk2xF1uLuhV+auud2mWjM5zAfBgNVH 1555 SMEGDAWgBTSxLDSkdRMEXGzYcs9of7dqGrU4zASBgNVHRMBAf8ECDAGAQH/AgEA 1556 MDMGCCsGAQUFBwEBBCcwJTAjBggrBgEFBQcwAYYXaHR0cDovL29jc3AuZ29kYWR 1557 keS5jb20wRgYDVR0fBD8wPTA7oDmgN4Y1aHR0cDovL2NlcnRpZmljYXRlcy5nb2 1558 RhZGR5LmNvbS9yZXBvc2l0b3J5L2dkcm9vdC5jcmwwSwYDVR0gBEQwQjBABgRVH 1559 SAAMDgwNgYIKwYBBQUHAgEWKmh0dHA6Ly9jZXJ0aWZpY2F0ZXMuZ29kYWRkeS5j 1560 b20vcmVwb3NpdG9yeTAOBgNVHQ8BAf8EBAMCAQYwDQYJKoZIhvcNAQEFBQADggE 1561 BANKGwOy9+aG2Z+5mC6IGOgRQjhVyrEp0lVPLN8tESe8HkGsz2ZbwlFalEzAFPI 1562 UyIXvJxwqoJKSQ3kbTJSMUA2fCENZvD117esyfxVgqwcSeIaha86ykRvOe5GPLL 1563 5CkKSkB2XIsKd83ASe8T+5o0yGPwLPk9Qnt0hCqU7S+8MxZC9Y7lhyVJEnfzuz9 1564 p0iRFEUOOjZv2kWzRaJBydTXRE4+uXR21aITVSzGh6O1mawGhId/dQb8vxRMDsx 1565 uxN89txJx9OjxUUAiKEngHUuHqDTMBqLdElrRhjZkAzVvb3du6/KFUJheqwNTrZ 1566 EjYx8WnM25sgVjOuH0aBsXBTWVU+4= 1567 -----END CERTIFICATE----- 1568 -----BEGIN CERTIFICATE----- 1569 MIIE+zCCBGSgAwIBAgICAQ0wDQYJKoZIhvcNAQEFBQAwgbsxJDAiBgNVBAcTG1Z 1570 hbGlDZXJ0IFZhbGlkYXRpb24gTmV0d29yazEXMBUGA1UEChMOVmFsaUNlcnQsIE 1571 luYy4xNTAzBgNVBAsTLFZhbGlDZXJ0IENsYXNzIDIgUG9saWN5IFZhbGlkYXRpb 1572 24gQXV0aG9yaXR5MSEwHwYDVQQDExhodHRwOi8vd3d3LnZhbGljZXJ0LmNvbS8x 1573 IDAeBgkqhkiG9w0BCQEWEWluZm9AdmFsaWNlcnQuY29tMB4XDTA0MDYyOTE3MDY 1574 yMFoXDTI0MDYyOTE3MDYyMFowYzELMAkGA1UEBhMCVVMxITAfBgNVBAoTGFRoZS 1575 BHbyBEYWRkeSBHcm91cCwgSW5jLjExMC8GA1UECxMoR28gRGFkZHkgQ2xhc3MgM 1576 iBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eTCCASAwDQYJKoZIhvcNAQEBBQADggEN 1577 ADCCAQgCggEBAN6d1+pXGEmhW+vXX0iG6r7d/+TvZxz0ZWizV3GgXne77ZtJ6XC 1578 APVYYYwhv2vLM0D9/AlQiVBDYsoHUwHU9S3/Hd8M+eKsaA7Ugay9qK7HFiH7Eux 1579 6wwdhFJ2+qN1j3hybX2C32qRe3H3I2TqYXP2WYktsqbl2i/ojgC95/5Y0V4evLO 1580 tXiEqITLdiOr18SPaAIBQi2XKVlOARFmR6jYGB0xUGlcmIbYsUfb18aQr4CUWWo 1581 riMYavx4A6lNf4DD+qta/KFApMoZFv6yyO9ecw3ud72a9nmYvLEHZ6IVDd2gWMZ 1582 Eewo+YihfukEHU1jPEX44dMX4/7VpkI+EdOqXG68CAQOjggHhMIIB3TAdBgNVHQ 1583 4EFgQU0sSw0pHUTBFxs2HLPaH+3ahq1OMwgdIGA1UdIwSByjCBx6GBwaSBvjCBu 1584 zEkMCIGA1UEBxMbVmFsaUNlcnQgVmFsaWRhdGlvbiBOZXR3b3JrMRcwFQYDVQQK 1585 Ew5WYWxpQ2VydCwgSW5jLjE1MDMGA1UECxMsVmFsaUNlcnQgQ2xhc3MgMiBQb2x 1586 pY3kgVmFsaWRhdGlvbiBBdXRob3JpdHkxITAfBgNVBAMTGGh0dHA6Ly93d3cudm 1587 FsaWNlcnQuY29tLzEgMB4GCSqGSIb3DQEJARYRaW5mb0B2YWxpY2VydC5jb22CA 1588 QEwDwYDVR0TAQH/BAUwAwEB/zAzBggrBgEFBQcBAQQnMCUwIwYIKwYBBQUHMAGG 1589 F2h0dHA6Ly9vY3NwLmdvZGFkZHkuY29tMEQGA1UdHwQ9MDswOaA3oDWGM2h0dHA 1590 6Ly9jZXJ0aWZpY2F0ZXMuZ29kYWRkeS5jb20vcmVwb3NpdG9yeS9yb290LmNybD 1591 BLBgNVHSAERDBCMEAGBFUdIAAwODA2BggrBgEFBQcCARYqaHR0cDovL2NlcnRpZ 1592 mljYXRlcy5nb2RhZGR5LmNvbS9yZXBvc2l0b3J5MA4GA1UdDwEB/wQEAwIBBjAN 1593 BgkqhkiG9w0BAQUFAAOBgQC1QPmnHfbq/qQaQlpE9xXUhUaJwL6e4+PrxeNYiY+ 1594 Sn1eocSxI0YGyeR+sBjUZsE4OWBsUs5iB0QQeyAfJg594RAoYC5jcdnplDQ1tgM 1595 QLARzLrUc+cb53S8wGd9D0VmsfSxOaFIqII6hR8INMqzW/Rn453HWkrugp++85j 1596 09VZw== 1597 -----END CERTIFICATE----- 1598 -----BEGIN CERTIFICATE----- 1599 MIIC5zCCAlACAQEwDQYJKoZIhvcNAQEFBQAwgbsxJDAiBgNVBAcTG1ZhbGlDZXJ 1600 0IFZhbGlkYXRpb24gTmV0d29yazEXMBUGA1UEChMOVmFsaUNlcnQsIEluYy4xNT 1601 AzBgNVBAsTLFZhbGlDZXJ0IENsYXNzIDIgUG9saWN5IFZhbGlkYXRpb24gQXV0a 1602 G9yaXR5MSEwHwYDVQQDExhodHRwOi8vd3d3LnZhbGljZXJ0LmNvbS8xIDAeBgkq 1603 hkiG9w0BCQEWEWluZm9AdmFsaWNlcnQuY29tMB4XDTk5MDYyNjAwMTk1NFoXDTE 1604 5MDYyNjAwMTk1NFowgbsxJDAiBgNVBAcTG1ZhbGlDZXJ0IFZhbGlkYXRpb24gTm 1605 V0d29yazEXMBUGA1UEChMOVmFsaUNlcnQsIEluYy4xNTAzBgNVBAsTLFZhbGlDZ 1606 XJ0IENsYXNzIDIgUG9saWN5IFZhbGlkYXRpb24gQXV0aG9yaXR5MSEwHwYDVQQD 1607 ExhodHRwOi8vd3d3LnZhbGljZXJ0LmNvbS8xIDAeBgkqhkiG9w0BCQEWEWluZm9 1608 AdmFsaWNlcnQuY29tMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDOOnHK5a 1609 vIWZJV16vYdA757tn2VUdZZUcOBVXc65g2PFxTXdMwzzjsvUGJ7SVCCSRrCl6zf 1610 N1SLUzm1NZ9WlmpZdRJEy0kTRxQb7XBhVQ7/nHk01xC+YDgkRoKWzk2Z/M/VXwb 1611 P7RfZHM047QSv4dk+NoS/zcnwbNDu+97bi5p9wIDAQABMA0GCSqGSIb3DQEBBQU 1612 AA4GBADt/UG9vUJSZSWI4OB9L+KXIPqeCgfYrx+jFzug6EILLGACOTb2oWH+heQ 1613 C1u+mNr0HZDzTuIYEZoDJJKPTEjlbVUjP9UNV+mWwD5MlM/Mtsq2azSiGM5bUMM 1614 j4QssxsodyamEwCW/POuZ6lcg5Ktz885hZo+L7tdEy8W9ViH0Pd 1615 -----END CERTIFICATE----- 1617 Appendix C. Notes on implementing base64url encoding without padding 1619 This appendix describes how to implement base64url encoding and 1620 decoding functions without padding based upon standard base64 1621 encoding and decoding functions that do use padding. 1623 To be concrete, example C# code implementing these functions is shown 1624 below. Similar code could be used in other languages. 1626 static string base64urlencode(byte [] arg) 1627 { 1628 string s = Convert.ToBase64String(arg); // Standard base64 encoder 1629 s = s.Split('=')[0]; // Remove any trailing '='s 1630 s = s.Replace('+', '-'); // 62nd char of encoding 1631 s = s.Replace('/', '_'); // 63rd char of encoding 1632 return s; 1633 } 1635 static byte [] base64urldecode(string arg) 1636 { 1637 string s = arg; 1638 s = s.Replace('-', '+'); // 62nd char of encoding 1639 s = s.Replace('_', '/'); // 63rd char of encoding 1640 switch (s.Length % 4) // Pad with trailing '='s 1641 { 1642 case 0: break; // No pad chars in this case 1643 case 2: s += "=="; break; // Two pad chars 1644 case 3: s += "="; break; // One pad char 1645 default: throw new System.Exception( 1646 "Illegal base64url string!"); 1647 } 1648 return Convert.FromBase64String(s); // Standard base64 decoder 1649 } 1651 As per the example code above, the number of '=' padding characters 1652 that needs to be added to the end of a base64url encoded string 1653 without padding to turn it into one with padding is a deterministic 1654 function of the length of the encoded string. Specifically, if the 1655 length mod 4 is 0, no padding is added; if the length mod 4 is 2, two 1656 '=' padding characters are added; if the length mod 4 is 3, one '=' 1657 padding character is added; if the length mod 4 is 1, the input is 1658 malformed. 1660 An example correspondence between unencoded and encoded values 1661 follows. The byte sequence below encodes into the string below, 1662 which when decoded, reproduces the byte sequence. 1663 3 236 255 224 193 1664 A-z_4ME 1666 Appendix D. Acknowledgements 1668 Solutions for signing JSON content were previously explored by Magic 1669 Signatures [MagicSignatures], JSON Simple Sign [JSS], and Canvas 1670 Applications [CanvasApp], all of which influenced this draft. Dirk 1671 Balfanz, Yaron Y. Goland, John Panzer, and Paul Tarjan all made 1672 significant contributions to the design of this specification. 1674 Thanks to Axel Nennker for his early implementation and feedback on 1675 the JWS and JWE specifications. 1677 Appendix E. Document History 1679 [[ to be removed by the RFC editor before publication as an RFC ]] 1681 -05 1683 o Added statement that "StringOrURI values are compared as case- 1684 sensitive strings with no transformations or canonicalizations 1685 applied". 1687 o Indented artwork elements to better distinguish them from the body 1688 text. 1690 -04 1692 o Completed JSON Security Considerations section, including 1693 considerations about rejecting input with duplicate member names. 1695 o Completed security considerations on the use of a SHA-1 hash when 1696 computing "x5t" (x.509 certificate thumbprint) values. 1698 o Refer to the registries as the primary sources of defined values 1699 and then secondarily reference the sections defining the initial 1700 contents of the registries. 1702 o Normatively reference XML DSIG 2.0 [W3C.CR-xmldsig-core2-20120124] 1703 for its security considerations. 1705 o Added this language to Registration Templates: "This name is case 1706 sensitive. Names that match other registered names in a case 1707 insensitive manner SHOULD NOT be accepted." 1709 o Reference draft-jones-jose-jws-json-serialization instead of 1710 draft-jones-json-web-signature-json-serialization. 1712 o Described additional open issues. 1714 o Applied editorial suggestions. 1716 -03 1718 o Added the "cty" (content type) header parameter for declaring type 1719 information about the secured content, as opposed to the "typ" 1720 (type) header parameter, which declares type information about 1721 this object. 1723 o Added "Collision Resistant Namespace" to the terminology section. 1725 o Reference ITU.X690.1994 for DER encoding. 1727 o Added an example JWS using ECDSA P-521 SHA-512. This has 1728 particular illustrative value because of the use of the 521 bit 1729 integers in the key and signature values. This is also an example 1730 in which the payload is not a base64url encoded JSON object. 1732 o Added an example "x5c" value. 1734 o No longer say "the UTF-8 representation of the JWS Secured Input 1735 (which is the same as the ASCII representation)". Just call it 1736 "the ASCII representation of the JWS Secured Input". 1738 o Added Registration Template sections for defined registries. 1740 o Added Registry Contents sections to populate registry values. 1742 o Changed name of the JSON Web Signature and Encryption "typ" Values 1743 registry to be the JSON Web Signature and Encryption Type Values 1744 registry, since it is used for more than just values of the "typ" 1745 parameter. 1747 o Moved registries JSON Web Signature and Encryption Header 1748 Parameters and JSON Web Signature and Encryption Type Values to 1749 the JWS specification. 1751 o Numerous editorial improvements. 1753 -02 1755 o Clarified that it is an error when a "kid" value is included and 1756 no matching key is found. 1758 o Removed assumption that "kid" (key ID) can only refer to an 1759 asymmetric key. 1761 o Clarified that JWSs with duplicate Header Parameter Names MUST be 1762 rejected. 1764 o Clarified the relationship between "typ" header parameter values 1765 and MIME types. 1767 o Registered application/jws MIME type and "JWS" typ header 1768 parameter value. 1770 o Simplified JWK terminology to get replace the "JWK Key Object" and 1771 "JWK Container Object" terms with simply "JSON Web Key (JWK)" and 1772 "JSON Web Key Set (JWK Set)" and to eliminate potential confusion 1773 between single keys and sets of keys. As part of this change, the 1774 header parameter name for a public key value was changed from 1775 "jpk" (JSON Public Key) to "jwk" (JSON Web Key). 1777 o Added suggestion on defining additional header parameters such as 1778 "x5t#S256" in the future for certificate thumbprints using hash 1779 algorithms other than SHA-1. 1781 o Specify RFC 2818 server identity validation, rather than RFC 6125 1782 (paralleling the same decision in the OAuth specs). 1784 o Generalized language to refer to Message Authentication Codes 1785 (MACs) rather than Hash-based Message Authentication Codes (HMACs) 1786 unless in a context specific to HMAC algorithms. 1788 o Reformatted to give each header parameter its own section heading. 1790 -01 1792 o Moved definition of Plaintext JWSs (using "alg":"none") here from 1793 the JWT specification since this functionality is likely to be 1794 useful in more contexts that just for JWTs. 1796 o Added "jpk" and "x5c" header parameters for including JWK public 1797 keys and X.509 certificate chains directly in the header. 1799 o Clarified that this specification is defining the JWS Compact 1800 Serialization. Referenced the new JWS-JS spec, which defines the 1801 JWS JSON Serialization. 1803 o Added text "New header parameters should be introduced sparingly 1804 since an implementation that does not understand a parameter MUST 1805 reject the JWS". 1807 o Clarified that the order of the creation and validation steps is 1808 not significant in cases where there are no dependencies between 1809 the inputs and outputs of the steps. 1811 o Changed "no canonicalization is performed" to "no canonicalization 1812 need be performed". 1814 o Corrected the Magic Signatures reference. 1816 o Made other editorial improvements suggested by JOSE working group 1817 participants. 1819 -00 1821 o Created the initial IETF draft based upon 1822 draft-jones-json-web-signature-04 with no normative changes. 1824 o Changed terminology to no longer call both digital signatures and 1825 HMACs "signatures". 1827 Authors' Addresses 1829 Michael B. Jones 1830 Microsoft 1832 Email: mbj@microsoft.com 1833 URI: http://self-issued.info/ 1835 John Bradley 1836 Ping Identity 1838 Email: ve7jtb@ve7jtb.com 1840 Nat Sakimura 1841 Nomura Research Institute 1843 Email: n-sakimura@nri.co.jp