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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 17, 2013 Ping Identity 6 N. Sakimura 7 NRI 8 July 16, 2012 10 JSON Web Signature (JWS) 11 draft-ietf-jose-json-web-signature-04 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 17, 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 . . . . . . . . . . . . . . . . . . . . . 12 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 . . . . . . . . 18 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 . . . . . . . . . . . . . . . . . . 21 99 A.1.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 21 100 A.1.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 23 101 A.1.3. Validating . . . . . . . . . . . . . . . . . . . . . . 23 102 A.2. JWS using RSA SHA-256 . . . . . . . . . . . . . . . . . . 24 103 A.2.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 24 104 A.2.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 27 105 A.2.3. Validating . . . . . . . . . . . . . . . . . . . . . . 27 106 A.3. JWS using ECDSA P-256 SHA-256 . . . . . . . . . . . . . . 27 107 A.3.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 27 108 A.3.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 29 109 A.3.3. Validating . . . . . . . . . . . . . . . . . . . . . . 29 110 A.4. JWS using ECDSA P-521 SHA-512 . . . . . . . . . . . . . . 30 111 A.4.1. Encoding . . . . . . . . . . . . . . . . . . . . . . . 30 112 A.4.2. Decoding . . . . . . . . . . . . . . . . . . . . . . . 32 113 A.4.3. Validating . . . . . . . . . . . . . . . . . . . . . . 32 114 A.5. Example Plaintext JWS . . . . . . . . . . . . . . . . . . 32 115 Appendix B. "x5c" (X.509 Certificate Chain) Example . . . . . . . 33 116 Appendix C. Notes on implementing base64url encoding without 117 padding . . . . . . . . . . . . . . . . . . . . . . . 35 118 Appendix D. Acknowledgements . . . . . . . . . . . . . . . . . . 36 119 Appendix E. Document History . . . . . . . . . . . . . . . . . . 36 120 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 39 122 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]. 203 3. JSON Web Signature (JWS) Overview 205 JWS represents digitally signed or MACed content using JSON data 206 structures and base64url encoding. The representation consists of 207 three parts: the JWS Header, the JWS Payload, and the JWS Signature. 208 In the Compact Serialization, the three parts are base64url-encoded 209 for transmission, and represented as the concatenation of the encoded 210 strings in that order, with the three strings being separated by 211 period ('.') characters. (A JSON Serialization for this information 212 is defined in the separate JSON Web Signature JSON Serialization 213 (JWS-JS) [JWS-JS] specification.) 214 The JWS Header describes the signature or MAC method and parameters 215 employed. The JWS Payload is the message content to be secured. The 216 JWS Signature ensures the integrity of both the JWS Header and the 217 JWS Payload. 219 3.1. Example JWS 221 The following example JWS Header declares that the encoded object is 222 a JSON Web Token (JWT) [JWT] and the JWS Header and the JWS Payload 223 are secured using the HMAC SHA-256 algorithm: 224 {"typ":"JWT", 225 "alg":"HS256"} 227 Base64url encoding the bytes of the UTF-8 representation of the JWS 228 Header yields this Encoded JWS Header value: 229 eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9 231 The following is an example of a JSON object that can be used as a 232 JWS Payload. (Note that the payload can be any content, and need not 233 be a representation of a JSON object.) 234 {"iss":"joe", 235 "exp":1300819380, 236 "http://example.com/is_root":true} 238 Base64url encoding the bytes of the UTF-8 representation of the JSON 239 object yields the following Encoded JWS Payload (with line breaks for 240 display purposes only): 241 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 242 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 244 Computing the HMAC of the bytes of the ASCII [USASCII] representation 245 of the JWS Secured Input (the concatenation of the Encoded JWS 246 Header, a period ('.') character, and the Encoded JWS Payload) with 247 the HMAC SHA-256 algorithm using the key specified in Appendix A.1 248 and base64url encoding the result yields this Encoded JWS Signature 249 value: 250 dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk 252 Concatenating these parts in the order Header.Payload.Signature with 253 period characters between the parts yields this complete JWS 254 representation (with line breaks for display purposes only): 255 eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9 256 . 257 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 258 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 259 . 260 dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk 261 This computation is illustrated in more detail in Appendix A.1. 263 4. JWS Header 265 The members of the JSON object represented by the JWS Header describe 266 the digital signature or MAC applied to the Encoded JWS Header and 267 the Encoded JWS Payload and optionally additional properties of the 268 JWS. The Header Parameter Names within this object MUST be unique; 269 JWSs with duplicate Header Parameter Names MUST be rejected. 270 Implementations MUST understand the entire contents of the header; 271 otherwise, the JWS MUST be rejected. 273 There are three classes of Header Parameter Names: Reserved Header 274 Parameter Names, Public Header Parameter Names, and Private Header 275 Parameter Names. 277 4.1. Reserved Header Parameter Names 279 The following header parameter names are reserved with meanings as 280 defined below. All the names are short because a core goal of JWSs 281 is for the representations to be compact. 283 Additional reserved header parameter names MAY be defined via the 284 IANA JSON Web Signature and Encryption Header Parameters registry 285 Section 7.1. As indicated by the common registry, JWSs and JWEs 286 share a common header parameter space; when a parameter is used by 287 both specifications, its usage must be compatible between the 288 specifications. 290 4.1.1. "alg" (Algorithm) Header Parameter 292 The "alg" (algorithm) header parameter identifies the cryptographic 293 algorithm used to secure the JWS. The algorithm specified by the 294 "alg" value MUST be supported by the implementation and there MUST be 295 a key for use with that algorithm associated with the party that 296 digitally signed or MACed the content or the JWS MUST be rejected. 297 "alg" values SHOULD either be registered in the IANA JSON Web 298 Signature and Encryption Algorithms registry [JWA] or be a URI that 299 contains a Collision Resistant Namespace. The "alg" value is a case 300 sensitive string containing a StringOrURI value. This header 301 parameter is REQUIRED. 303 A list of defined "alg" values can be found in the IANA JSON Web 304 Signature and Encryption Algorithms registry [JWA]; the initial 305 contents of this registry is the values defined in Section 3.1 of the 306 JSON Web Algorithms (JWA) [JWA] specification. 308 4.1.2. "jku" (JWK Set URL) Header Parameter 310 The "jku" (JWK Set URL) header parameter is a URI [RFC3986] that 311 refers to a resource for a set of JSON-encoded public keys, one of 312 which corresponds to the key used to digitally sign the JWS. The 313 keys MUST be encoded as a JSON Web Key Set (JWK Set) [JWK]. The 314 protocol used to acquire the resource MUST provide integrity 315 protection; an HTTP GET request to retrieve the certificate MUST use 316 TLS [RFC2818] [RFC5246]; the identity of the server MUST be 317 validated, as per Section 3.1 of HTTP Over TLS [RFC2818]. This 318 header parameter is OPTIONAL. 320 4.1.3. "jwk" (JSON Web Key) Header Parameter 322 The "jwk" (JSON Web Key) header parameter is a public key that 323 corresponds to the key used to digitally sign the JWS. This key is 324 represented as a JSON Web Key [JWK]. This header parameter is 325 OPTIONAL. 327 4.1.4. "x5u" (X.509 URL) Header Parameter 329 The "x5u" (X.509 URL) header parameter is a URI [RFC3986] that refers 330 to a resource for the X.509 public key certificate or certificate 331 chain [RFC5280] corresponding to the key used to digitally sign the 332 JWS. The identified resource MUST provide a representation of the 333 certificate or certificate chain that conforms to RFC 5280 [RFC5280] 334 in PEM encoded form [RFC1421]. The certificate containing the public 335 key of the entity that digitally signed the JWS MUST be the first 336 certificate. This MAY be followed by additional certificates, with 337 each subsequent certificate being the one used to certify the 338 previous one. The protocol used to acquire the resource MUST provide 339 integrity protection; an HTTP GET request to retrieve the certificate 340 MUST use TLS [RFC2818] [RFC5246]; the identity of the server MUST be 341 validated, as per Section 3.1 of HTTP Over TLS [RFC2818]. This 342 header parameter is OPTIONAL. 344 4.1.5. "x5t" (X.509 Certificate Thumbprint) Header Parameter 346 The "x5t" (X.509 Certificate Thumbprint) header parameter provides a 347 base64url encoded SHA-1 thumbprint (a.k.a. digest) of the DER 348 encoding of the X.509 certificate [RFC5280] corresponding to the key 349 used to digitally sign the JWS. This header parameter is OPTIONAL. 351 If, in the future, certificate thumbprints need to be computed using 352 hash functions other than SHA-1, it is suggested that additional 353 related header parameters be defined for that purpose. For example, 354 it is suggested that a new "x5t#S256" (X.509 Certificate Thumbprint 355 using SHA-256) header parameter could be defined by registering it in 356 the IANA JSON Web Signature and Encryption Header Parameters registry 357 Section 7.1. 359 4.1.6. "x5c" (X.509 Certificate Chain) Header Parameter 361 The "x5c" (X.509 Certificate Chain) header parameter contains the 362 X.509 public key certificate or certificate chain [RFC5280] 363 corresponding to the key used to digitally sign the JWS. The 364 certificate or certificate chain is represented as an array of 365 certificate values. Each value is a base64 encoded ([RFC4648] 366 Section 4 - not base64url encoded) DER [ITU.X690.1994] PKIX 367 certificate value. The certificate containing the public key of the 368 entity that digitally signed the JWS MUST be the first certificate. 369 This MAY be followed by additional certificates, with each subsequent 370 certificate being the one used to certify the previous one. The 371 recipient MUST verify the certificate chain according to [RFC5280] 372 and reject the JWS if any validation failure occurs. This header 373 parameter is OPTIONAL. 375 See Appendix B for an example "x5c" value. 377 4.1.7. "kid" (Key ID) Header Parameter 379 The "kid" (key ID) header parameter is a hint indicating which key 380 was used to secure the JWS. This parameter allows originators to 381 explicitly signal a change of key to recipients. Should the 382 recipient be unable to locate a key corresponding to the "kid" value, 383 they SHOULD treat that condition as an error. The interpretation of 384 the "kid" value is unspecified. Its value MUST be a string. This 385 header parameter is OPTIONAL. 387 When used with a JWK, the "kid" value MAY be used to match a JWK 388 "kid" parameter value. 390 4.1.8. "typ" (Type) Header Parameter 392 The "typ" (type) header parameter is used to declare the type of this 393 object. The type value "JWS" MAY be used to indicate that this 394 object is a JWS. The "typ" value is a case sensitive string. This 395 header parameter is OPTIONAL. 397 MIME Media Type [RFC2046] values MAY be used as "typ" values. 399 "typ" values SHOULD either be registered in the IANA JSON Web 400 Signature and Encryption Type Values registry Section 7.2 or be a URI 401 that contains a Collision Resistant Namespace. 403 4.1.9. "cty" (Content Type) Header Parameter 405 The "cty" (content type) header parameter is used to declare the type 406 of the secured content (the Payload). The "cty" value is a case 407 sensitive string. This header parameter is OPTIONAL. 409 The values used for the "cty" header parameter come from the same 410 value space as the "typ" header parameter, with the same rules 411 applying. 413 4.2. Public Header Parameter Names 415 Additional header parameter names can be defined by those using JWSs. 416 However, in order to prevent collisions, any new header parameter 417 name SHOULD either be registered in the IANA JSON Web Signature and 418 Encryption Header Parameters registry Section 7.1 or be a URI that 419 contains a Collision Resistant Namespace. In each case, the definer 420 of the name or value needs to take reasonable precautions to make 421 sure they are in control of the part of the namespace they use to 422 define the header parameter name. 424 New header parameters should be introduced sparingly, as they can 425 result in non-interoperable JWSs. 427 4.3. Private Header Parameter Names 429 A producer and consumer of a JWS may agree to any header parameter 430 name that is not a Reserved Name Section 4.1 or a Public Name 431 Section 4.2. Unlike Public Names, these private names are subject to 432 collision and should be used with caution. 434 5. Rules for Creating and Validating a JWS 436 To create a JWS, one MUST perform these steps. The order of the 437 steps is not significant in cases where there are no dependencies 438 between the inputs and outputs of the steps. 440 1. Create the content to be used as the JWS Payload. 442 2. Base64url encode the bytes of the JWS Payload. This encoding 443 becomes the Encoded JWS Payload. 445 3. Create a JWS Header containing the desired set of header 446 parameters. Note that white space is explicitly allowed in the 447 representation and no canonicalization need be performed before 448 encoding. 450 4. Base64url encode the bytes of the UTF-8 representation of the JWS 451 Header to create the Encoded JWS Header. 453 5. Compute the JWS Signature in the manner defined for the 454 particular algorithm being used. The JWS Secured Input is always 455 the concatenation of the Encoded JWS Header, a period ('.') 456 character, and the Encoded JWS Payload. The "alg" (algorithm) 457 header parameter MUST be present in the JSON Header, with the 458 algorithm value accurately representing the algorithm used to 459 construct the JWS Signature. 461 6. Base64url encode the representation of the JWS Signature to 462 create the Encoded JWS Signature. 464 7. The three encoded parts, taken together, are the result. The 465 Compact Serialization of this result is the concatenation of the 466 Encoded JWS Header, the Encoded JWS Payload, and the Encoded JWS 467 Signature in that order, with the three strings being separated 468 by period ('.') characters. 470 When validating a JWS, the following steps MUST be taken. The order 471 of the steps is not significant in cases where there are no 472 dependencies between the inputs and outputs of the steps. If any of 473 the listed steps fails, then the JWS MUST be rejected. 475 1. Parse the three parts of the input (which are separated by period 476 characters when using the JWS Compact Serialization) into the 477 Encoded JWS Header, the Encoded JWS Payload, and the Encoded JWS 478 Signature. 480 2. The Encoded JWS Header MUST be successfully base64url decoded 481 following the restriction given in this specification that no 482 padding characters have been used. 484 3. The resulting JWS Header MUST be completely valid JSON syntax 485 conforming to RFC 4627 [RFC4627]. 487 4. The resulting JWS Header MUST be validated to only include 488 parameters and values whose syntax and semantics are both 489 understood and supported. 491 5. The Encoded JWS Payload MUST be successfully base64url decoded 492 following the restriction given in this specification that no 493 padding characters have been used. 495 6. The Encoded JWS Signature MUST be successfully base64url decoded 496 following the restriction given in this specification that no 497 padding characters have been used. 499 7. The JWS Signature MUST be successfully validated against the JWS 500 Secured Input (the concatenation of the Encoded JWS Header, a 501 period ('.') character, and the Encoded JWS Payload) in the 502 manner defined for the algorithm being used, which MUST be 503 accurately represented by the value of the "alg" (algorithm) 504 header parameter, which MUST be present. 506 Processing a JWS inevitably requires comparing known strings to 507 values in the header. For example, in checking what the algorithm 508 is, the Unicode string encoding "alg" will be checked against the 509 member names in the JWS Header to see if there is a matching header 510 parameter name. A similar process occurs when determining if the 511 value of the "alg" header parameter represents a supported algorithm. 513 Comparisons between JSON strings and other Unicode strings MUST be 514 performed as specified below: 516 1. Remove any JSON applied escaping to produce an array of Unicode 517 code points. 519 2. Unicode Normalization [USA15] MUST NOT be applied at any point to 520 either the JSON string or to the string it is to be compared 521 against. 523 3. Comparisons between the two strings MUST be performed as a 524 Unicode code point to code point equality comparison. 526 6. Securing JWSs with Cryptographic Algorithms 528 JWS uses cryptographic algorithms to digitally sign or MAC the JWS 529 Header and the JWS Payload. The JSON Web Algorithms (JWA) [JWA] 530 specification describes a set of cryptographic algorithms and 531 identifiers to be used with this specification. Specifically, 532 Section 3.1 specifies a set of "alg" (algorithm) header parameter 533 values intended for use this specification. It also describes the 534 semantics and operations that are specific to these algorithms and 535 algorithm families. 537 Public keys employed for digital signing can be identified using the 538 Header Parameter methods described in Section 4.1 or can be 539 distributed using methods that are outside the scope of this 540 specification. 542 7. IANA Considerations 544 The following registration procedure is used for all the registries 545 established by this specification. 547 Values are registered with a Specification Required [RFC5226] after a 548 two week review period on the [TBD]@ietf.org mailing list, on the 549 advice of one or more Designated Experts. However, to allow for the 550 allocation of values prior to publication, the Designated Expert(s) 551 may approve registration once they are satisfied that such a 552 specification will be published. 554 Registration requests must be sent to the [TBD]@ietf.org mailing list 555 for review and comment, with an appropriate subject (e.g., "Request 556 for access token type: example"). [[ Note to RFC-EDITOR: The name of 557 the mailing list should be determined in consultation with the IESG 558 and IANA. Suggested name: jose-reg-review. ]] 560 Within the review period, the Designated Expert(s) will either 561 approve or deny the registration request, communicating this decision 562 to the review list and IANA. Denials should include an explanation 563 and, if applicable, suggestions as to how to make the request 564 successful. 566 IANA must only accept registry updates from the Designated Expert(s), 567 and should direct all requests for registration to the review mailing 568 list. 570 7.1. JSON Web Signature and Encryption Header Parameters Registry 572 This specification establishes the IANA JSON Web Signature and 573 Encryption Header Parameters registry for reserved JWS and JWE header 574 parameter names. The registry records the reserved header parameter 575 name and a reference to the specification that defines it. The same 576 Header Parameter Name may be registered multiple times, provided that 577 the parameter usage is compatible between the specifications. 579 7.1.1. Registration Template 581 Header Parameter Name: 582 The name requested (e.g., "example"). This name is case 583 sensitive. Names that match other registered names in a case 584 insensitive manner SHOULD NOT be accepted. 586 Change Controller: 587 For standards-track RFCs, state "IETF". For others, give the name 588 of the responsible party. Other details (e.g., postal address, 589 e-mail address, home page URI) may also be included. 591 Specification Document(s): 592 Reference to the document that specifies the parameter, preferably 593 including a URI that can be used to retrieve a copy of the 594 document. An indication of the relevant sections may also be 595 included, but is not required. 597 7.1.2. Initial Registry Contents 599 This specification registers the Header Parameter Names defined in 600 Section 4.1 in this registry. 602 o Header Parameter Name: "alg" 604 o Change Controller: IETF 606 o Specification Document(s): Section 4.1.1 of [[ this document ]] 608 o Header Parameter Name: "jku" 610 o Change Controller: IETF 612 o Specification Document(s): Section 4.1.2 of [[ this document ]] 614 o Header Parameter Name: "jwk" 616 o Change Controller: IETF 618 o Specification document(s): Section 4.1.3 of [[ this document ]] 620 o Header Parameter Name: "x5u" 622 o Change Controller: IETF 624 o Specification Document(s): Section 4.1.4 of [[ this document ]] 626 o Header Parameter Name: "x5t" 628 o Change Controller: IETF 630 o Specification Document(s): Section 4.1.5 of [[ this document ]] 632 o Header Parameter Name: "x5c" 634 o Change Controller: IETF 636 o Specification Document(s): Section 4.1.6 of [[ this document ]] 637 o Header Parameter Name: "kid" 639 o Change Controller: IETF 641 o Specification Document(s): Section 4.1.7 of [[ this document ]] 643 o Header Parameter Name: "typ" 645 o Change Controller: IETF 647 o Specification Document(s): Section 4.1.8 of [[ this document ]] 649 o Header Parameter Name: "cty" 651 o Change Controller: IETF 653 o Specification Document(s): Section 4.1.9 of [[ this document ]] 655 7.2. JSON Web Signature and Encryption Type Values Registry 657 This specification establishes the IANA JSON Web Signature and 658 Encryption Type Values registry for values of the JWS and JWE "typ" 659 (type) header parameter. It is RECOMMENDED that all registered "typ" 660 values also include a MIME Media Type [RFC2046] value that the 661 registered value is a short name for. The registry records the "typ" 662 value, the MIME type value that it is an abbreviation for (if any), 663 and a reference to the specification that defines it. 665 MIME Media Type [RFC2046] values MUST NOT be directly registered as 666 new "typ" values; rather, new "typ" values MAY be registered as short 667 names for MIME types. 669 7.2.1. Registration Template 671 "typ" Header Parameter Value: 672 The name requested (e.g., "example"). This name is case 673 sensitive. Names that match other registered names in a case 674 insensitive manner SHOULD NOT be accepted. 676 Abbreviation for MIME Type: 677 The MIME type that this name is an abbreviation for (e.g., 678 "application/example"). 680 Change Controller: 681 For standards-track RFCs, state "IETF". For others, give the name 682 of the responsible party. Other details (e.g., postal address, 683 e-mail address, home page URI) may also be included. 685 Specification Document(s): 686 Reference to the document that specifies the parameter, preferably 687 including a URI that can be used to retrieve a copy of the 688 document. An indication of the relevant sections may also be 689 included, but is not required. 691 7.2.2. Initial Registry Contents 693 This specification registers the "JWS" type value in this registry: 695 o "typ" Header Parameter Value: "JWS" 697 o Abbreviation for MIME type: application/jws 699 o Change Controller: IETF 701 o Specification Document(s): Section 4.1.8 of [[ this document ]] 703 7.3. Media Type Registration 705 7.3.1. Registry Contents 707 This specification registers the "application/jws" Media Type 708 [RFC2046] in the MIME Media Type registry [RFC4288] to indicate that 709 the content is a JWS using the Compact Serialization. 711 o Type name: application 713 o Subtype name: jws 715 o Required parameters: n/a 717 o Optional parameters: n/a 719 o Encoding considerations: JWS values are encoded as a series of 720 base64url encoded values (some of which may be the empty string) 721 separated by period ('.') characters 723 o Security considerations: See the Security Considerations section 724 of this document 726 o Interoperability considerations: n/a 728 o Published specification: [[ this document ]] 730 o Applications that use this media type: OpenID Connect, Mozilla 731 Browser ID, Salesforce, Google, numerous others that use signed 732 JWTs 734 o Additional information: Magic number(s): n/a, File extension(s): 735 n/a, Macintosh file type code(s): n/a 737 o Person & email address to contact for further information: Michael 738 B. Jones, mbj@microsoft.com 740 o Intended usage: COMMON 742 o Restrictions on usage: none 744 o Author: Michael B. Jones, mbj@microsoft.com 746 o Change Controller: IETF 748 8. Security Considerations 750 8.1. Cryptographic Security Considerations 752 All of the security issues faced by any cryptographic application 753 must be faced by a JWS/JWE/JWK agent. Among these issues are 754 protecting the user's private key, preventing various attacks, and 755 helping the user avoid mistakes such as inadvertently encrypting a 756 message for the wrong recipient. The entire list of security 757 considerations is beyond the scope of this document, but some 758 significant concerns are listed here. 760 All the security considerations in XML DSIG 2.0 761 [W3C.CR-xmldsig-core2-20120124], also apply to this specification, 762 other than those that are XML specific. Likewise, many of the best 763 practices documented in XML Signature Best Practices 764 [W3C.WD-xmldsig-bestpractices-20110809] also apply to this 765 specification, other than those that are XML specific. 767 Keys are only as strong as the amount of entropy used to generate 768 them. A minimum of 128 bits of entropy should be used for all keys, 769 and depending upon the application context, more may be required. In 770 particular, it may be difficult to generate sufficiently random 771 values in some browsers and application environments. 773 When utilizing TLS to retrieve information, the authority providing 774 the resource MUST be authenticated and the information retrieved MUST 775 be free from modification. 777 When cryptographic algorithms are implemented in such a way that 778 successful operations take a different amount of time than 779 unsuccessful operations, attackers may be able to use the time 780 difference to obtain information about the keys employed. Therefore, 781 such timing differences must be avoided. 783 A SHA-1 hash is used when computing "x5t" (x.509 certificate 784 thumbprint) values, for compatibility reasons. Should an effective 785 means of producing SHA-1 hash collisions be developed, and should an 786 attacker wish to interfere with the use of a known certificate on a 787 given system, this could be accomplished by creating another 788 certificate whose SHA-1 hash value is the same and adding it to the 789 certificate store used by the intended victim. A prerequisite to 790 this attack succeeding is the attacker having write access to the 791 intended victim's certificate store. 793 If, in the future, certificate thumbprints need to be computed using 794 hash functions other than SHA-1, it is suggested that additional 795 related header parameters be defined for that purpose. For example, 796 it is suggested that a new "x5t#S256" (X.509 Certificate Thumbprint 797 using SHA-256) header parameter could be defined and used. 799 8.2. JSON Security Considerations 801 Strict JSON validation is a security requirement. If malformed JSON 802 is received, then the intent of the sender is impossible to reliably 803 discern. Ambiguous and potentially exploitable situations could 804 arise if the JSON parser used does not reject malformed JSON syntax. 806 Section 2.2 of the JavaScript Object Notation (JSON) specification 807 [RFC4627] states "The names within an object SHOULD be unique", 808 whereas this specification states that "Header Parameter Names within 809 this object MUST be unique; JWSs with duplicate Header Parameter 810 Names MUST be rejected". Thus, this specification requires that the 811 Section 2.2 "SHOULD" be treated as a "MUST". Ambiguous and 812 potentially exploitable situations could arise if the JSON parser 813 used does not enforce the uniqueness of member names. 815 8.3. Unicode Comparison Security Considerations 817 Header parameter names and algorithm names are Unicode strings. For 818 security reasons, the representations of these names must be compared 819 verbatim after performing any escape processing (as per RFC 4627 820 [RFC4627], Section 2.5). This means, for instance, that these JSON 821 strings must compare as being equal ("sig", "\u0073ig"), whereas 822 these must all compare as being not equal to the first set or to each 823 other ("SIG", "Sig", "si\u0047"). 825 JSON strings MAY contain characters outside the Unicode Basic 826 Multilingual Plane. For instance, the G clef character (U+1D11E) may 827 be represented in a JSON string as "\uD834\uDD1E". Ideally, JWS 828 implementations SHOULD ensure that characters outside the Basic 829 Multilingual Plane are preserved and compared correctly; 830 alternatively, if this is not possible due to these characters 831 exercising limitations present in the underlying JSON implementation, 832 then input containing them MUST be rejected. 834 9. Open Issues 836 [[ to be removed by the RFC editor before publication as an RFC ]] 838 The following items remain to be considered or done in this draft: 840 o Should we define an optional nonce and/or timestamp header 841 parameter? (Use of a nonce is an effective countermeasure to some 842 kinds of attacks.) 844 o Some have objected to the language "Implementations MUST 845 understand the entire contents of the header; otherwise, the JWS 846 MUST be rejected" in this spec and the related language in the 847 JWE, JWK, and JWT specs. Others believe that this is essential in 848 a security specification. 850 o Finish the Security Considerations section. 852 10. References 854 10.1. Normative References 856 [ITU.X690.1994] 857 International Telecommunications Union, "Information 858 Technology - ASN.1 encoding rules: Specification of Basic 859 Encoding Rules (BER), Canonical Encoding Rules (CER) and 860 Distinguished Encoding Rules (DER)", ITU-T Recommendation 861 X.690, 1994. 863 [JWA] Jones, M., "JSON Web Algorithms (JWA)", July 2012. 865 [JWK] Jones, M., "JSON Web Key (JWK)", July 2012. 867 [RFC1421] Linn, J., "Privacy Enhancement for Internet Electronic 868 Mail: Part I: Message Encryption and Authentication 869 Procedures", RFC 1421, February 1993. 871 [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail 872 Extensions (MIME) Part Two: Media Types", RFC 2046, 873 November 1996. 875 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 876 Requirement Levels", BCP 14, RFC 2119, March 1997. 878 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. 880 [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 881 10646", STD 63, RFC 3629, November 2003. 883 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 884 Resource Identifier (URI): Generic Syntax", STD 66, 885 RFC 3986, January 2005. 887 [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and 888 Registration Procedures", BCP 13, RFC 4288, December 2005. 890 [RFC4627] Crockford, D., "The application/json Media Type for 891 JavaScript Object Notation (JSON)", RFC 4627, July 2006. 893 [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data 894 Encodings", RFC 4648, October 2006. 896 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 897 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 898 May 2008. 900 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security 901 (TLS) Protocol Version 1.2", RFC 5246, August 2008. 903 [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., 904 Housley, R., and W. Polk, "Internet X.509 Public Key 905 Infrastructure Certificate and Certificate Revocation List 906 (CRL) Profile", RFC 5280, May 2008. 908 [USA15] Davis, M., Whistler, K., and M. Duerst, "Unicode 909 Normalization Forms", Unicode Standard Annex 15, 09 2009. 911 [USASCII] American National Standards Institute, "Coded Character 912 Set -- 7-bit American Standard Code for Information 913 Interchange", ANSI X3.4, 1986. 915 [W3C.WD-xmldsig-bestpractices-20110809] 916 Datta, P. and F. Hirsch, "XML Signature Best Practices", 917 World Wide Web Consortium WD WD-xmldsig-bestpractices- 918 20110809, August 2011, . 921 10.2. Informative References 923 [CanvasApp] 924 Facebook, "Canvas Applications", 2010. 926 [JSS] Bradley, J. and N. Sakimura (editor), "JSON Simple Sign", 927 September 2010. 929 [JWE] Jones, M., Rescorla, E., and J. Hildebrand, "JSON Web 930 Encryption (JWE)", July 2012. 932 [JWS-JS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web 933 Signature JSON Serialization (JWS-JS)", July 2012. 935 [JWT] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token 936 (JWT)", July 2012. 938 [MagicSignatures] 939 Panzer (editor), J., Laurie, B., and D. Balfanz, "Magic 940 Signatures", January 2011. 942 [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally 943 Unique IDentifier (UUID) URN Namespace", RFC 4122, 944 July 2005. 946 [W3C.CR-xmldsig-core2-20120124] 947 Reagle, J., Hirsch, F., Cantor, S., Roessler, T., 948 Eastlake, D., Yiu, K., Solo, D., and P. Datta, "XML 949 Signature Syntax and Processing Version 2.0", World Wide 950 Web Consortium CR CR-xmldsig-core2-20120124, January 2012, 951 . 953 Appendix A. JWS Examples 955 This section provides several examples of JWSs. While these examples 956 all represent JSON Web Tokens (JWTs) [JWT], the payload can be any 957 base64url encoded content. 959 A.1. JWS using HMAC SHA-256 961 A.1.1. Encoding 963 The following example JWS Header declares that the data structure is 964 a JSON Web Token (JWT) [JWT] and the JWS Secured Input is secured 965 using the HMAC SHA-256 algorithm. 966 {"typ":"JWT", 967 "alg":"HS256"} 969 The following byte array contains the UTF-8 representation of the JWS 970 Header: 972 [123, 34, 116, 121, 112, 34, 58, 34, 74, 87, 84, 34, 44, 13, 10, 32, 973 34, 97, 108, 103, 34, 58, 34, 72, 83, 50, 53, 54, 34, 125] 975 Base64url encoding these bytes yields this Encoded JWS Header value: 976 eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9 978 The JWS Payload used in this example is the bytes of the UTF-8 979 representation of the JSON object below. (Note that the payload can 980 be any base64url encoded sequence of bytes, and need not be a 981 base64url encoded JSON object.) 982 {"iss":"joe", 983 "exp":1300819380, 984 "http://example.com/is_root":true} 986 The following byte array, which is the UTF-8 representation of the 987 JSON object above, is the JWS Payload: 989 [123, 34, 105, 115, 115, 34, 58, 34, 106, 111, 101, 34, 44, 13, 10, 990 32, 34, 101, 120, 112, 34, 58, 49, 51, 48, 48, 56, 49, 57, 51, 56, 991 48, 44, 13, 10, 32, 34, 104, 116, 116, 112, 58, 47, 47, 101, 120, 97, 992 109, 112, 108, 101, 46, 99, 111, 109, 47, 105, 115, 95, 114, 111, 993 111, 116, 34, 58, 116, 114, 117, 101, 125] 995 Base64url encoding the above yields the Encoded JWS Payload value 996 (with line breaks for display purposes only): 997 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 998 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1000 Concatenating the Encoded JWS Header, a period character, and the 1001 Encoded JWS Payload yields this JWS Secured Input value (with line 1002 breaks for display purposes only): 1003 eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9 1004 . 1005 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 1006 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1008 The ASCII representation of the JWS Secured Input is the following 1009 byte array: 1011 [101, 121, 74, 48, 101, 88, 65, 105, 79, 105, 74, 75, 86, 49, 81, 1012 105, 76, 65, 48, 75, 73, 67, 74, 104, 98, 71, 99, 105, 79, 105, 74, 1013 73, 85, 122, 73, 49, 78, 105, 74, 57, 46, 101, 121, 74, 112, 99, 51, 1014 77, 105, 79, 105, 74, 113, 98, 50, 85, 105, 76, 65, 48, 75, 73, 67, 1015 74, 108, 101, 72, 65, 105, 79, 106, 69, 122, 77, 68, 65, 52, 77, 84, 1016 107, 122, 79, 68, 65, 115, 68, 81, 111, 103, 73, 109, 104, 48, 100, 1017 72, 65, 54, 76, 121, 57, 108, 101, 71, 70, 116, 99, 71, 120, 108, 76, 1018 109, 78, 118, 98, 83, 57, 112, 99, 49, 57, 121, 98, 50, 57, 48, 73, 1019 106, 112, 48, 99, 110, 86, 108, 102, 81] 1021 HMACs are generated using keys. This example uses the key 1022 represented by the following byte array: 1024 [3, 35, 53, 75, 43, 15, 165, 188, 131, 126, 6, 101, 119, 123, 166, 1025 143, 90, 179, 40, 230, 240, 84, 201, 40, 169, 15, 132, 178, 210, 80, 1026 46, 191, 211, 251, 90, 146, 210, 6, 71, 239, 150, 138, 180, 195, 119, 1027 98, 61, 34, 61, 46, 33, 114, 5, 46, 79, 8, 192, 205, 154, 245, 103, 1028 208, 128, 163] 1030 Running the HMAC SHA-256 algorithm on the bytes of the ASCII 1031 representation of the JWS Secured Input with this key yields the 1032 following byte array: 1034 [116, 24, 223, 180, 151, 153, 224, 37, 79, 250, 96, 125, 216, 173, 1035 187, 186, 22, 212, 37, 77, 105, 214, 191, 240, 91, 88, 5, 88, 83, 1036 132, 141, 121] 1038 Base64url encoding the above HMAC output yields the Encoded JWS 1039 Signature value: 1040 dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk 1042 A.1.2. Decoding 1044 Decoding the JWS requires base64url decoding the Encoded JWS Header, 1045 Encoded JWS Payload, and Encoded JWS Signature to produce the JWS 1046 Header, JWS Payload, and JWS Signature byte arrays. The byte array 1047 containing the UTF-8 representation of the JWS Header is decoded into 1048 the JWS Header string. 1050 A.1.3. Validating 1052 Next we validate the decoded results. Since the "alg" parameter in 1053 the header is "HS256", we validate the HMAC SHA-256 value contained 1054 in the JWS Signature. If any of the validation steps fail, the JWS 1055 MUST be rejected. 1057 First, we validate that the JWS Header string is legal JSON. 1059 To validate the HMAC value, we repeat the previous process of using 1060 the correct key and the ASCII representation of the JWS Secured Input 1061 as input to the HMAC SHA-256 function and then taking the output and 1062 determining if it matches the JWS Signature. If it matches exactly, 1063 the HMAC has been validated. 1065 A.2. JWS using RSA SHA-256 1067 A.2.1. Encoding 1069 The JWS Header in this example is different from the previous example 1070 in two ways: First, because a different algorithm is being used, the 1071 "alg" value is different. Second, for illustration purposes only, 1072 the optional "typ" parameter is not used. (This difference is not 1073 related to the algorithm employed.) The JWS Header used is: 1074 {"alg":"RS256"} 1076 The following byte array contains the UTF-8 representation of the JWS 1077 Header: 1079 [123, 34, 97, 108, 103, 34, 58, 34, 82, 83, 50, 53, 54, 34, 125] 1081 Base64url encoding these bytes yields this Encoded JWS Header value: 1082 eyJhbGciOiJSUzI1NiJ9 1084 The JWS Payload used in this example, which follows, is the same as 1085 in the previous example. Since the Encoded JWS Payload will 1086 therefore be the same, its computation is not repeated here. 1087 {"iss":"joe", 1088 "exp":1300819380, 1089 "http://example.com/is_root":true} 1091 Concatenating the Encoded JWS Header, a period character, and the 1092 Encoded JWS Payload yields this JWS Secured Input value (with line 1093 breaks for display purposes only): 1094 eyJhbGciOiJSUzI1NiJ9 1095 . 1096 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 1097 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1099 The ASCII representation of the JWS Secured Input is the following 1100 byte array: 1102 [101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 83, 85, 122, 73, 1103 49, 78, 105, 74, 57, 46, 101, 121, 74, 112, 99, 51, 77, 105, 79, 105, 1104 74, 113, 98, 50, 85, 105, 76, 65, 48, 75, 73, 67, 74, 108, 101, 72, 1105 65, 105, 79, 106, 69, 122, 77, 68, 65, 52, 77, 84, 107, 122, 79, 68, 1106 65, 115, 68, 81, 111, 103, 73, 109, 104, 48, 100, 72, 65, 54, 76, 1107 121, 57, 108, 101, 71, 70, 116, 99, 71, 120, 108, 76, 109, 78, 118, 1108 98, 83, 57, 112, 99, 49, 57, 121, 98, 50, 57, 48, 73, 106, 112, 48, 1109 99, 110, 86, 108, 102, 81] 1111 The RSA key consists of a public part (Modulus, Exponent), and a 1112 Private Exponent. The values of the RSA key used in this example, 1113 presented as the byte arrays representing big endian integers are: 1115 +-----------+-------------------------------------------------------+ 1116 | Parameter | Value | 1117 | Name | | 1118 +-----------+-------------------------------------------------------+ 1119 | Modulus | [161, 248, 22, 10, 226, 227, 201, 180, 101, 206, 141, | 1120 | | 45, 101, 98, 99, 54, 43, 146, 125, 190, 41, 225, 240, | 1121 | | 36, 119, 252, 22, 37, 204, 144, 161, 54, 227, 139, | 1122 | | 217, 52, 151, 197, 182, 234, 99, 221, 119, 17, 230, | 1123 | | 124, 116, 41, 249, 86, 176, 251, 138, 143, 8, 154, | 1124 | | 220, 75, 105, 137, 60, 193, 51, 63, 83, 237, 208, 25, | 1125 | | 184, 119, 132, 37, 47, 236, 145, 79, 228, 133, 119, | 1126 | | 105, 89, 75, 234, 66, 128, 211, 44, 15, 85, 191, 98, | 1127 | | 148, 79, 19, 3, 150, 188, 110, 155, 223, 110, 189, | 1128 | | 210, 189, 163, 103, 142, 236, 160, 198, 104, 247, 1, | 1129 | | 179, 141, 191, 251, 56, 200, 52, 44, 226, 254, 109, | 1130 | | 39, 250, 222, 74, 90, 72, 116, 151, 157, 212, 185, | 1131 | | 207, 154, 222, 196, 199, 91, 5, 133, 44, 44, 15, 94, | 1132 | | 248, 165, 193, 117, 3, 146, 249, 68, 232, 237, 100, | 1133 | | 193, 16, 198, 182, 71, 96, 154, 164, 120, 58, 235, | 1134 | | 156, 108, 154, 215, 85, 49, 48, 80, 99, 139, 131, | 1135 | | 102, 92, 111, 111, 122, 130, 163, 150, 112, 42, 31, | 1136 | | 100, 27, 130, 211, 235, 242, 57, 34, 25, 73, 31, 182, | 1137 | | 134, 135, 44, 87, 22, 245, 10, 248, 53, 141, 154, | 1138 | | 139, 157, 23, 195, 64, 114, 143, 127, 135, 216, 154, | 1139 | | 24, 216, 252, 171, 103, 173, 132, 89, 12, 46, 207, | 1140 | | 117, 147, 57, 54, 60, 7, 3, 77, 111, 96, 111, 158, | 1141 | | 33, 224, 84, 86, 202, 229, 233, 161] | 1142 | Exponent | [1, 0, 1] | 1143 | Private | [18, 174, 113, 164, 105, 205, 10, 43, 195, 126, 82, | 1144 | Exponent | 108, 69, 0, 87, 31, 29, 97, 117, 29, 100, 233, 73, | 1145 | | 112, 123, 98, 89, 15, 157, 11, 165, 124, 150, 60, 64, | 1146 | | 30, 63, 207, 47, 44, 211, 189, 236, 136, 229, 3, 191, | 1147 | | 198, 67, 155, 11, 40, 200, 47, 125, 55, 151, 103, 31, | 1148 | | 82, 19, 238, 216, 193, 90, 37, 216, 213, 206, 160, 2, | 1149 | | 94, 227, 171, 46, 139, 127, 121, 33, 111, 198, 59, | 1150 | | 234, 86, 39, 83, 180, 6, 68, 198, 161, 81, 39, 217, | 1151 | | 178, 149, 69, 64, 160, 187, 225, 163, 5, 86, 152, 45, | 1152 | | 78, 159, 222, 95, 100, 37, 241, 77, 75, 113, 52, 65, | 1153 | | 181, 93, 199, 59, 155, 74, 237, 204, 146, 172, 227, | 1154 | | 146, 126, 55, 245, 125, 12, 253, 94, 117, 129, 250, | 1155 | | 81, 44, 143, 73, 97, 169, 235, 11, 128, 248, 168, 7, | 1156 | | 70, 114, 138, 85, 255, 70, 71, 31, 52, 37, 6, 59, | 1157 | | 157, 83, 100, 47, 94, 222, 30, 132, 214, 19, 8, 26, | 1158 | | 250, 92, 34, 208, 81, 40, 91, 214, 59, 148, 59, 86, | 1159 | | 93, 137, 138, 5, 104, 84, 19, 229, 60, 60, 108, 101, | 1160 | | 37, 255, 31, 227, 78, 61, 220, 112, 240, 213, 100, | 1161 | | 80, 253, 164, 139, 161, 46, 16, 78, 157, 235, 159, | 1162 | | 184, 24, 129, 225, 196, 189, 242, 93, 146, 71, 244, | 1163 | | 80, 200, 101, 146, 121, 104, 231, 115, 52, 244, 65, | 1164 | | 79, 117, 167, 80, 225, 57, 84, 110, 58, 138, 115, | 1165 | | 157] | 1166 +-----------+-------------------------------------------------------+ 1168 The RSA private key (Modulus, Private Exponent) is then passed to the 1169 RSA signing function, which also takes the hash type, SHA-256, and 1170 the bytes of the ASCII representation of the JWS Secured Input as 1171 inputs. The result of the digital signature is a byte array, which 1172 represents a big endian integer. In this example, it is: 1174 [112, 46, 33, 137, 67, 232, 143, 209, 30, 181, 216, 45, 191, 120, 69, 1175 243, 65, 6, 174, 27, 129, 255, 247, 115, 17, 22, 173, 209, 113, 125, 1176 131, 101, 109, 66, 10, 253, 60, 150, 238, 221, 115, 162, 102, 62, 81, 1177 102, 104, 123, 0, 11, 135, 34, 110, 1, 135, 237, 16, 115, 249, 69, 1178 229, 130, 173, 252, 239, 22, 216, 90, 121, 142, 232, 198, 109, 219, 1179 61, 184, 151, 91, 23, 208, 148, 2, 190, 237, 213, 217, 217, 112, 7, 1180 16, 141, 178, 129, 96, 213, 248, 4, 12, 167, 68, 87, 98, 184, 31, 1181 190, 127, 249, 217, 46, 10, 231, 111, 36, 242, 91, 51, 187, 230, 244, 1182 74, 230, 30, 177, 4, 10, 203, 32, 4, 77, 62, 249, 18, 142, 212, 1, 1183 48, 121, 91, 212, 189, 59, 65, 238, 202, 208, 102, 171, 101, 25, 129, 1184 253, 228, 141, 247, 127, 55, 45, 195, 139, 159, 175, 221, 59, 239, 1185 177, 139, 93, 163, 204, 60, 46, 176, 47, 158, 58, 65, 214, 18, 202, 1186 173, 21, 145, 18, 115, 160, 95, 35, 185, 232, 56, 250, 175, 132, 157, 1187 105, 132, 41, 239, 90, 30, 136, 121, 130, 54, 195, 212, 14, 96, 69, 1188 34, 165, 68, 200, 242, 122, 122, 45, 184, 6, 99, 209, 108, 247, 202, 1189 234, 86, 222, 64, 92, 178, 33, 90, 69, 178, 194, 85, 102, 181, 90, 1190 193, 167, 72, 160, 112, 223, 200, 163, 42, 70, 149, 67, 208, 25, 238, 1191 251, 71] 1193 Base64url encoding the digital signature produces this value for the 1194 Encoded JWS Signature (with line breaks for display purposes only): 1195 cC4hiUPoj9Eetdgtv3hF80EGrhuB__dzERat0XF9g2VtQgr9PJbu3XOiZj5RZmh7 1196 AAuHIm4Bh-0Qc_lF5YKt_O8W2Fp5jujGbds9uJdbF9CUAr7t1dnZcAcQjbKBYNX4 1197 BAynRFdiuB--f_nZLgrnbyTyWzO75vRK5h6xBArLIARNPvkSjtQBMHlb1L07Qe7K 1198 0GarZRmB_eSN9383LcOLn6_dO--xi12jzDwusC-eOkHWEsqtFZESc6BfI7noOPqv 1199 hJ1phCnvWh6IeYI2w9QOYEUipUTI8np6LbgGY9Fs98rqVt5AXLIhWkWywlVmtVrB 1200 p0igcN_IoypGlUPQGe77Rw 1202 A.2.2. Decoding 1204 Decoding the JWS requires base64url decoding the Encoded JWS Header, 1205 Encoded JWS Payload, and Encoded JWS Signature to produce the JWS 1206 Header, JWS Payload, and JWS Signature byte arrays. The byte array 1207 containing the UTF-8 representation of the JWS Header is decoded into 1208 the JWS Header string. 1210 A.2.3. Validating 1212 Since the "alg" parameter in the header is "RS256", we validate the 1213 RSA SHA-256 digital signature contained in the JWS Signature. If any 1214 of the validation steps fail, the JWS MUST be rejected. 1216 First, we validate that the JWS Header string is legal JSON. 1218 Validating the JWS Signature is a little different from the previous 1219 example. First, we base64url decode the Encoded JWS Signature to 1220 produce a digital signature S to check. We then pass (n, e), S and 1221 the bytes of the ASCII representation of the JWS Secured Input to an 1222 RSA signature verifier that has been configured to use the SHA-256 1223 hash function. 1225 A.3. JWS using ECDSA P-256 SHA-256 1227 A.3.1. Encoding 1229 The JWS Header for this example differs from the previous example 1230 because a different algorithm is being used. The JWS Header used is: 1231 {"alg":"ES256"} 1233 The following byte array contains the UTF-8 representation of the JWS 1234 Header: 1236 [123, 34, 97, 108, 103, 34, 58, 34, 69, 83, 50, 53, 54, 34, 125] 1238 Base64url encoding these bytes yields this Encoded JWS Header value: 1240 eyJhbGciOiJFUzI1NiJ9 1242 The JWS Payload used in this example, which follows, is the same as 1243 in the previous examples. Since the Encoded JWS Payload will 1244 therefore be the same, its computation is not repeated here. 1245 {"iss":"joe", 1246 "exp":1300819380, 1247 "http://example.com/is_root":true} 1249 Concatenating the Encoded JWS Header, a period character, and the 1250 Encoded JWS Payload yields this JWS Secured Input value (with line 1251 breaks for display purposes only): 1252 eyJhbGciOiJFUzI1NiJ9 1253 . 1254 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 1255 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1257 The ASCII representation of the JWS Secured Input is the following 1258 byte array: 1260 [101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 70, 85, 122, 73, 1261 49, 78, 105, 74, 57, 46, 101, 121, 74, 112, 99, 51, 77, 105, 79, 105, 1262 74, 113, 98, 50, 85, 105, 76, 65, 48, 75, 73, 67, 74, 108, 101, 72, 1263 65, 105, 79, 106, 69, 122, 77, 68, 65, 52, 77, 84, 107, 122, 79, 68, 1264 65, 115, 68, 81, 111, 103, 73, 109, 104, 48, 100, 72, 65, 54, 76, 1265 121, 57, 108, 101, 71, 70, 116, 99, 71, 120, 108, 76, 109, 78, 118, 1266 98, 83, 57, 112, 99, 49, 57, 121, 98, 50, 57, 48, 73, 106, 112, 48, 1267 99, 110, 86, 108, 102, 81] 1269 The ECDSA key consists of a public part, the EC point (x, y), and a 1270 private part d. The values of the ECDSA key used in this example, 1271 presented as the byte arrays representing three 256 bit big endian 1272 integers are: 1274 +-----------+-------------------------------------------------------+ 1275 | Parameter | Value | 1276 | Name | | 1277 +-----------+-------------------------------------------------------+ 1278 | x | [127, 205, 206, 39, 112, 246, 196, 93, 65, 131, 203, | 1279 | | 238, 111, 219, 75, 123, 88, 7, 51, 53, 123, 233, 239, | 1280 | | 19, 186, 207, 110, 60, 123, 209, 84, 69] | 1281 | y | [199, 241, 68, 205, 27, 189, 155, 126, 135, 44, 223, | 1282 | | 237, 185, 238, 185, 244, 179, 105, 93, 110, 169, 11, | 1283 | | 36, 173, 138, 70, 35, 40, 133, 136, 229, 173] | 1284 | d | [142, 155, 16, 158, 113, 144, 152, 191, 152, 4, 135, | 1285 | | 223, 31, 93, 119, 233, 203, 41, 96, 110, 190, 210, | 1286 | | 38, 59, 95, 87, 194, 19, 223, 132, 244, 178] | 1287 +-----------+-------------------------------------------------------+ 1288 The ECDSA private part d is then passed to an ECDSA signing function, 1289 which also takes the curve type, P-256, the hash type, SHA-256, and 1290 the bytes of the ASCII representation of the JWS Secured Input as 1291 inputs. The result of the digital signature is the EC point (R, S), 1292 where R and S are unsigned integers. In this example, the R and S 1293 values, given as byte arrays representing big endian integers are: 1295 +--------+----------------------------------------------------------+ 1296 | Result | Value | 1297 | Name | | 1298 +--------+----------------------------------------------------------+ 1299 | R | [14, 209, 33, 83, 121, 99, 108, 72, 60, 47, 127, 21, 88, | 1300 | | 7, 212, 2, 163, 178, 40, 3, 58, 249, 124, 126, 23, 129, | 1301 | | 154, 195, 22, 158, 166, 101] | 1302 | S | [197, 10, 7, 211, 140, 60, 112, 229, 216, 241, 45, 175, | 1303 | | 8, 74, 84, 128, 166, 101, 144, 197, 242, 147, 80, 154, | 1304 | | 143, 63, 127, 138, 131, 163, 84, 213] | 1305 +--------+----------------------------------------------------------+ 1307 Concatenating the S array to the end of the R array and base64url 1308 encoding the result produces this value for the Encoded JWS Signature 1309 (with line breaks for display purposes only): 1310 DtEhU3ljbEg8L38VWAfUAqOyKAM6-Xx-F4GawxaepmXFCgfTjDxw5djxLa8ISlSA 1311 pmWQxfKTUJqPP3-Kg6NU1Q 1313 A.3.2. Decoding 1315 Decoding the JWS requires base64url decoding the Encoded JWS Header, 1316 Encoded JWS Payload, and Encoded JWS Signature to produce the JWS 1317 Header, JWS Payload, and JWS Signature byte arrays. The byte array 1318 containing the UTF-8 representation of the JWS Header is decoded into 1319 the JWS Header string. 1321 A.3.3. Validating 1323 Since the "alg" parameter in the header is "ES256", we validate the 1324 ECDSA P-256 SHA-256 digital signature contained in the JWS Signature. 1325 If any of the validation steps fail, the JWS MUST be rejected. 1327 First, we validate that the JWS Header string is legal JSON. 1329 Validating the JWS Signature is a little different from the first 1330 example. First, we base64url decode the Encoded JWS Signature as in 1331 the previous examples but we then need to split the 64 member byte 1332 array that must result into two 32 byte arrays, the first R and the 1333 second S. We then pass (x, y), (R, S) and the bytes of the ASCII 1334 representation of the JWS Secured Input to an ECDSA signature 1335 verifier that has been configured to use the P-256 curve with the 1336 SHA-256 hash function. 1338 As explained in Section 3.4 of the JSON Web Algorithms (JWA) [JWA] 1339 specification, the use of the K value in ECDSA means that we cannot 1340 validate the correctness of the digital signature in the same way we 1341 validated the correctness of the HMAC. Instead, implementations MUST 1342 use an ECDSA validator to validate the digital signature. 1344 A.4. JWS using ECDSA P-521 SHA-512 1346 A.4.1. Encoding 1348 The JWS Header for this example differs from the previous example 1349 because a different ECDSA curve and hash function are used. The JWS 1350 Header used is: 1351 {"alg":"ES512"} 1353 The following byte array contains the UTF-8 representation of the JWS 1354 Header: 1356 [123, 34, 97, 108, 103, 34, 58, 34, 69, 83, 53, 49, 50, 34, 125] 1358 Base64url encoding these bytes yields this Encoded JWS Header value: 1359 eyJhbGciOiJFUzUxMiJ9 1361 The JWS Payload used in this example, is the ASCII string "Payload". 1362 The representation of this string is the byte array: 1364 [80, 97, 121, 108, 111, 97, 100] 1366 Base64url encoding these bytes yields the Encoded JWS Payload value: 1367 UGF5bG9hZA 1369 Concatenating the Encoded JWS Header, a period character, and the 1370 Encoded JWS Payload yields this JWS Secured Input value: 1371 eyJhbGciOiJFUzUxMiJ9.UGF5bG9hZA 1373 The ASCII representation of the JWS Secured Input is the following 1374 byte array: 1376 [101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 70, 85, 122, 85, 1377 120, 77, 105, 74, 57, 46, 85, 71, 70, 53, 98, 71, 57, 104, 90, 65] 1379 The ECDSA key consists of a public part, the EC point (x, y), and a 1380 private part d. The values of the ECDSA key used in this example, 1381 presented as the byte arrays representing three 521 bit big endian 1382 integers are: 1384 +-----------+-------------------------------------------------------+ 1385 | Parameter | Value | 1386 | Name | | 1387 +-----------+-------------------------------------------------------+ 1388 | x | [1, 233, 41, 5, 15, 18, 79, 198, 188, 85, 199, 213, | 1389 | | 57, 51, 101, 223, 157, 239, 74, 176, 194, 44, 178, | 1390 | | 87, 152, 249, 52, 235, 4, 227, 198, 186, 227, 112, | 1391 | | 26, 87, 167, 145, 14, 157, 129, 191, 54, 49, 89, 232, | 1392 | | 235, 203, 21, 93, 99, 73, 244, 189, 182, 204, 248, | 1393 | | 169, 76, 92, 89, 199, 170, 193, 1, 164] | 1394 | y | [0, 52, 166, 68, 14, 55, 103, 80, 210, 55, 31, 209, | 1395 | | 189, 194, 200, 243, 183, 29, 47, 78, 229, 234, 52, | 1396 | | 50, 200, 21, 204, 163, 21, 96, 254, 93, 147, 135, | 1397 | | 236, 119, 75, 85, 131, 134, 48, 229, 203, 191, 90, | 1398 | | 140, 190, 10, 145, 221, 0, 100, 198, 153, 154, 31, | 1399 | | 110, 110, 103, 250, 221, 237, 228, 200, 200, 246] | 1400 | d | [1, 142, 105, 111, 176, 52, 80, 88, 129, 221, 17, 11, | 1401 | | 72, 62, 184, 125, 50, 206, 73, 95, 227, 107, 55, 69, | 1402 | | 237, 242, 216, 202, 228, 240, 242, 83, 159, 70, 21, | 1403 | | 160, 233, 142, 171, 82, 179, 192, 197, 234, 196, 206, | 1404 | | 7, 81, 133, 168, 231, 187, 71, 222, 172, 29, 29, 231, | 1405 | | 123, 204, 246, 97, 53, 230, 61, 130] | 1406 +-----------+-------------------------------------------------------+ 1408 The ECDSA private part d is then passed to an ECDSA signing function, 1409 which also takes the curve type, P-521, the hash type, SHA-512, and 1410 the bytes of the ASCII representation of the JWS Secured Input as 1411 inputs. The result of the digital signature is the EC point (R, S), 1412 where R and S are unsigned integers. In this example, the R and S 1413 values, given as byte arrays representing big endian integers are: 1415 +--------+----------------------------------------------------------+ 1416 | Result | Value | 1417 | Name | | 1418 +--------+----------------------------------------------------------+ 1419 | R | [1, 220, 12, 129, 231, 171, 194, 209, 232, 135, 233, | 1420 | | 117, 247, 105, 122, 210, 26, 125, 192, 1, 217, 21, 82, | 1421 | | 91, 45, 240, 255, 83, 19, 34, 239, 71, 48, 157, 147, | 1422 | | 152, 105, 18, 53, 108, 163, 214, 68, 231, 62, 153, 150, | 1423 | | 106, 194, 164, 246, 72, 143, 138, 24, 50, 129, 223, 133, | 1424 | | 206, 209, 172, 63, 237, 119, 109] | 1425 | S | [0, 111, 6, 105, 44, 5, 41, 208, 128, 61, 152, 40, 92, | 1426 | | 61, 152, 4, 150, 66, 60, 69, 247, 196, 170, 81, 193, | 1427 | | 199, 78, 59, 194, 169, 16, 124, 9, 143, 42, 142, 131, | 1428 | | 48, 206, 238, 34, 175, 83, 203, 220, 159, 3, 107, 155, | 1429 | | 22, 27, 73, 111, 68, 68, 21, 238, 144, 229, 232, 148, | 1430 | | 188, 222, 59, 242, 103] | 1431 +--------+----------------------------------------------------------+ 1432 Concatenating the S array to the end of the R array and base64url 1433 encoding the result produces this value for the Encoded JWS Signature 1434 (with line breaks for display purposes only): 1435 AdwMgeerwtHoh-l192l60hp9wAHZFVJbLfD_UxMi70cwnZOYaRI1bKPWROc-mZZq 1436 wqT2SI-KGDKB34XO0aw_7XdtAG8GaSwFKdCAPZgoXD2YBJZCPEX3xKpRwcdOO8Kp 1437 EHwJjyqOgzDO7iKvU8vcnwNrmxYbSW9ERBXukOXolLzeO_Jn 1439 A.4.2. Decoding 1441 Decoding the JWS requires base64url decoding the Encoded JWS Header, 1442 Encoded JWS Payload, and Encoded JWS Signature to produce the JWS 1443 Header, JWS Payload, and JWS Signature byte arrays. The byte array 1444 containing the UTF-8 representation of the JWS Header is decoded into 1445 the JWS Header string. 1447 A.4.3. Validating 1449 Since the "alg" parameter in the header is "ES512", we validate the 1450 ECDSA P-521 SHA-512 digital signature contained in the JWS Signature. 1451 If any of the validation steps fail, the JWS MUST be rejected. 1453 First, we validate that the JWS Header string is legal JSON. 1455 Validating the JWS Signature is similar to the previous example. 1456 First, we base64url decode the Encoded JWS Signature as in the 1457 previous examples but we then need to split the 132 member byte array 1458 that must result into two 66 byte arrays, the first R and the second 1459 S. We then pass (x, y), (R, S) and the bytes of the ASCII 1460 representation of the JWS Secured Input to an ECDSA signature 1461 verifier that has been configured to use the P-521 curve with the 1462 SHA-512 hash function. 1464 As explained in Section 3.4 of the JSON Web Algorithms (JWA) [JWA] 1465 specification, the use of the K value in ECDSA means that we cannot 1466 validate the correctness of the digital signature in the same way we 1467 validated the correctness of the HMAC. Instead, implementations MUST 1468 use an ECDSA validator to validate the digital signature. 1470 A.5. Example Plaintext JWS 1472 The following example JWS Header declares that the encoded object is 1473 a Plaintext JWS: 1474 {"alg":"none"} 1476 Base64url encoding the bytes of the UTF-8 representation of the JWS 1477 Header yields this Encoded JWS Header: 1478 eyJhbGciOiJub25lIn0 1479 The JWS Payload used in this example, which follows, is the same as 1480 in the previous examples. Since the Encoded JWS Payload will 1481 therefore be the same, its computation is not repeated here. 1482 {"iss":"joe", 1483 "exp":1300819380, 1484 "http://example.com/is_root":true} 1486 The Encoded JWS Signature is the empty string. 1488 Concatenating these parts in the order Header.Payload.Signature with 1489 period characters between the parts yields this complete JWS (with 1490 line breaks for display purposes only): 1491 eyJhbGciOiJub25lIn0 1492 . 1493 eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt 1494 cGxlLmNvbS9pc19yb290Ijp0cnVlfQ 1495 . 1497 Appendix B. "x5c" (X.509 Certificate Chain) Example 1499 The string below is an example of a certificate chain that could be 1500 used as the value of an "x5c" (X.509 Certificate Chain) header 1501 parameter, per Section 4.1.6. 1502 -----BEGIN CERTIFICATE----- 1503 MIIE3jCCA8agAwIBAgICAwEwDQYJKoZIhvcNAQEFBQAwYzELMAkGA1UEBhMCVVM 1504 xITAfBgNVBAoTGFRoZSBHbyBEYWRkeSBHcm91cCwgSW5jLjExMC8GA1UECxMoR2 1505 8gRGFkZHkgQ2xhc3MgMiBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eTAeFw0wNjExM 1506 TYwMTU0MzdaFw0yNjExMTYwMTU0MzdaMIHKMQswCQYDVQQGEwJVUzEQMA4GA1UE 1507 CBMHQXJpem9uYTETMBEGA1UEBxMKU2NvdHRzZGFsZTEaMBgGA1UEChMRR29EYWR 1508 keS5jb20sIEluYy4xMzAxBgNVBAsTKmh0dHA6Ly9jZXJ0aWZpY2F0ZXMuZ29kYW 1509 RkeS5jb20vcmVwb3NpdG9yeTEwMC4GA1UEAxMnR28gRGFkZHkgU2VjdXJlIENlc 1510 nRpZmljYXRpb24gQXV0aG9yaXR5MREwDwYDVQQFEwgwNzk2OTI4NzCCASIwDQYJ 1511 KoZIhvcNAQEBBQADggEPADCCAQoCggEBAMQt1RWMnCZM7DI161+4WQFapmGBWTt 1512 wY6vj3D3HKrjJM9N55DrtPDAjhI6zMBS2sofDPZVUBJ7fmd0LJR4h3mUpfjWoqV 1513 Tr9vcyOdQmVZWt7/v+WIbXnvQAjYwqDL1CBM6nPwT27oDyqu9SoWlm2r4arV3aL 1514 GbqGmu75RpRSgAvSMeYddi5Kcju+GZtCpyz8/x4fKL4o/K1w/O5epHBp+YlLpyo 1515 7RJlbmr2EkRTcDCVw5wrWCs9CHRK8r5RsL+H0EwnWGu1NcWdrxcx+AuP7q2BNgW 1516 JCJjPOq8lh8BJ6qf9Z/dFjpfMFDniNoW1fho3/Rb2cRGadDAW/hOUoz+EDU8CAw 1517 EAAaOCATIwggEuMB0GA1UdDgQWBBT9rGEyk2xF1uLuhV+auud2mWjM5zAfBgNVH 1518 SMEGDAWgBTSxLDSkdRMEXGzYcs9of7dqGrU4zASBgNVHRMBAf8ECDAGAQH/AgEA 1519 MDMGCCsGAQUFBwEBBCcwJTAjBggrBgEFBQcwAYYXaHR0cDovL29jc3AuZ29kYWR 1520 keS5jb20wRgYDVR0fBD8wPTA7oDmgN4Y1aHR0cDovL2NlcnRpZmljYXRlcy5nb2 1521 RhZGR5LmNvbS9yZXBvc2l0b3J5L2dkcm9vdC5jcmwwSwYDVR0gBEQwQjBABgRVH 1522 SAAMDgwNgYIKwYBBQUHAgEWKmh0dHA6Ly9jZXJ0aWZpY2F0ZXMuZ29kYWRkeS5j 1523 b20vcmVwb3NpdG9yeTAOBgNVHQ8BAf8EBAMCAQYwDQYJKoZIhvcNAQEFBQADggE 1524 BANKGwOy9+aG2Z+5mC6IGOgRQjhVyrEp0lVPLN8tESe8HkGsz2ZbwlFalEzAFPI 1525 UyIXvJxwqoJKSQ3kbTJSMUA2fCENZvD117esyfxVgqwcSeIaha86ykRvOe5GPLL 1526 5CkKSkB2XIsKd83ASe8T+5o0yGPwLPk9Qnt0hCqU7S+8MxZC9Y7lhyVJEnfzuz9 1527 p0iRFEUOOjZv2kWzRaJBydTXRE4+uXR21aITVSzGh6O1mawGhId/dQb8vxRMDsx 1528 uxN89txJx9OjxUUAiKEngHUuHqDTMBqLdElrRhjZkAzVvb3du6/KFUJheqwNTrZ 1529 EjYx8WnM25sgVjOuH0aBsXBTWVU+4= 1530 -----END CERTIFICATE----- 1531 -----BEGIN CERTIFICATE----- 1532 MIIE+zCCBGSgAwIBAgICAQ0wDQYJKoZIhvcNAQEFBQAwgbsxJDAiBgNVBAcTG1Z 1533 hbGlDZXJ0IFZhbGlkYXRpb24gTmV0d29yazEXMBUGA1UEChMOVmFsaUNlcnQsIE 1534 luYy4xNTAzBgNVBAsTLFZhbGlDZXJ0IENsYXNzIDIgUG9saWN5IFZhbGlkYXRpb 1535 24gQXV0aG9yaXR5MSEwHwYDVQQDExhodHRwOi8vd3d3LnZhbGljZXJ0LmNvbS8x 1536 IDAeBgkqhkiG9w0BCQEWEWluZm9AdmFsaWNlcnQuY29tMB4XDTA0MDYyOTE3MDY 1537 yMFoXDTI0MDYyOTE3MDYyMFowYzELMAkGA1UEBhMCVVMxITAfBgNVBAoTGFRoZS 1538 BHbyBEYWRkeSBHcm91cCwgSW5jLjExMC8GA1UECxMoR28gRGFkZHkgQ2xhc3MgM 1539 iBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eTCCASAwDQYJKoZIhvcNAQEBBQADggEN 1540 ADCCAQgCggEBAN6d1+pXGEmhW+vXX0iG6r7d/+TvZxz0ZWizV3GgXne77ZtJ6XC 1541 APVYYYwhv2vLM0D9/AlQiVBDYsoHUwHU9S3/Hd8M+eKsaA7Ugay9qK7HFiH7Eux 1542 6wwdhFJ2+qN1j3hybX2C32qRe3H3I2TqYXP2WYktsqbl2i/ojgC95/5Y0V4evLO 1543 tXiEqITLdiOr18SPaAIBQi2XKVlOARFmR6jYGB0xUGlcmIbYsUfb18aQr4CUWWo 1544 riMYavx4A6lNf4DD+qta/KFApMoZFv6yyO9ecw3ud72a9nmYvLEHZ6IVDd2gWMZ 1545 Eewo+YihfukEHU1jPEX44dMX4/7VpkI+EdOqXG68CAQOjggHhMIIB3TAdBgNVHQ 1546 4EFgQU0sSw0pHUTBFxs2HLPaH+3ahq1OMwgdIGA1UdIwSByjCBx6GBwaSBvjCBu 1547 zEkMCIGA1UEBxMbVmFsaUNlcnQgVmFsaWRhdGlvbiBOZXR3b3JrMRcwFQYDVQQK 1548 Ew5WYWxpQ2VydCwgSW5jLjE1MDMGA1UECxMsVmFsaUNlcnQgQ2xhc3MgMiBQb2x 1549 pY3kgVmFsaWRhdGlvbiBBdXRob3JpdHkxITAfBgNVBAMTGGh0dHA6Ly93d3cudm 1550 FsaWNlcnQuY29tLzEgMB4GCSqGSIb3DQEJARYRaW5mb0B2YWxpY2VydC5jb22CA 1551 QEwDwYDVR0TAQH/BAUwAwEB/zAzBggrBgEFBQcBAQQnMCUwIwYIKwYBBQUHMAGG 1552 F2h0dHA6Ly9vY3NwLmdvZGFkZHkuY29tMEQGA1UdHwQ9MDswOaA3oDWGM2h0dHA 1553 6Ly9jZXJ0aWZpY2F0ZXMuZ29kYWRkeS5jb20vcmVwb3NpdG9yeS9yb290LmNybD 1554 BLBgNVHSAERDBCMEAGBFUdIAAwODA2BggrBgEFBQcCARYqaHR0cDovL2NlcnRpZ 1555 mljYXRlcy5nb2RhZGR5LmNvbS9yZXBvc2l0b3J5MA4GA1UdDwEB/wQEAwIBBjAN 1556 BgkqhkiG9w0BAQUFAAOBgQC1QPmnHfbq/qQaQlpE9xXUhUaJwL6e4+PrxeNYiY+ 1557 Sn1eocSxI0YGyeR+sBjUZsE4OWBsUs5iB0QQeyAfJg594RAoYC5jcdnplDQ1tgM 1558 QLARzLrUc+cb53S8wGd9D0VmsfSxOaFIqII6hR8INMqzW/Rn453HWkrugp++85j 1559 09VZw== 1560 -----END CERTIFICATE----- 1561 -----BEGIN CERTIFICATE----- 1562 MIIC5zCCAlACAQEwDQYJKoZIhvcNAQEFBQAwgbsxJDAiBgNVBAcTG1ZhbGlDZXJ 1563 0IFZhbGlkYXRpb24gTmV0d29yazEXMBUGA1UEChMOVmFsaUNlcnQsIEluYy4xNT 1564 AzBgNVBAsTLFZhbGlDZXJ0IENsYXNzIDIgUG9saWN5IFZhbGlkYXRpb24gQXV0a 1565 G9yaXR5MSEwHwYDVQQDExhodHRwOi8vd3d3LnZhbGljZXJ0LmNvbS8xIDAeBgkq 1566 hkiG9w0BCQEWEWluZm9AdmFsaWNlcnQuY29tMB4XDTk5MDYyNjAwMTk1NFoXDTE 1567 5MDYyNjAwMTk1NFowgbsxJDAiBgNVBAcTG1ZhbGlDZXJ0IFZhbGlkYXRpb24gTm 1568 V0d29yazEXMBUGA1UEChMOVmFsaUNlcnQsIEluYy4xNTAzBgNVBAsTLFZhbGlDZ 1569 XJ0IENsYXNzIDIgUG9saWN5IFZhbGlkYXRpb24gQXV0aG9yaXR5MSEwHwYDVQQD 1570 ExhodHRwOi8vd3d3LnZhbGljZXJ0LmNvbS8xIDAeBgkqhkiG9w0BCQEWEWluZm9 1571 AdmFsaWNlcnQuY29tMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDOOnHK5a 1572 vIWZJV16vYdA757tn2VUdZZUcOBVXc65g2PFxTXdMwzzjsvUGJ7SVCCSRrCl6zf 1573 N1SLUzm1NZ9WlmpZdRJEy0kTRxQb7XBhVQ7/nHk01xC+YDgkRoKWzk2Z/M/VXwb 1574 P7RfZHM047QSv4dk+NoS/zcnwbNDu+97bi5p9wIDAQABMA0GCSqGSIb3DQEBBQU 1575 AA4GBADt/UG9vUJSZSWI4OB9L+KXIPqeCgfYrx+jFzug6EILLGACOTb2oWH+heQ 1576 C1u+mNr0HZDzTuIYEZoDJJKPTEjlbVUjP9UNV+mWwD5MlM/Mtsq2azSiGM5bUMM 1577 j4QssxsodyamEwCW/POuZ6lcg5Ktz885hZo+L7tdEy8W9ViH0Pd 1578 -----END CERTIFICATE----- 1580 Appendix C. Notes on implementing base64url encoding without padding 1582 This appendix describes how to implement base64url encoding and 1583 decoding functions without padding based upon standard base64 1584 encoding and decoding functions that do use padding. 1586 To be concrete, example C# code implementing these functions is shown 1587 below. Similar code could be used in other languages. 1588 static string base64urlencode(byte [] arg) 1589 { 1590 string s = Convert.ToBase64String(arg); // Standard base64 encoder 1591 s = s.Split('=')[0]; // Remove any trailing '='s 1592 s = s.Replace('+', '-'); // 62nd char of encoding 1593 s = s.Replace('/', '_'); // 63rd char of encoding 1594 return s; 1595 } 1597 static byte [] base64urldecode(string arg) 1598 { 1599 string s = arg; 1600 s = s.Replace('-', '+'); // 62nd char of encoding 1601 s = s.Replace('_', '/'); // 63rd char of encoding 1602 switch (s.Length % 4) // Pad with trailing '='s 1603 { 1604 case 0: break; // No pad chars in this case 1605 case 2: s += "=="; break; // Two pad chars 1606 case 3: s += "="; break; // One pad char 1607 default: throw new System.Exception( 1608 "Illegal base64url string!"); 1609 } 1610 return Convert.FromBase64String(s); // Standard base64 decoder 1611 } 1613 As per the example code above, the number of '=' padding characters 1614 that needs to be added to the end of a base64url encoded string 1615 without padding to turn it into one with padding is a deterministic 1616 function of the length of the encoded string. Specifically, if the 1617 length mod 4 is 0, no padding is added; if the length mod 4 is 2, two 1618 '=' padding characters are added; if the length mod 4 is 3, one '=' 1619 padding character is added; if the length mod 4 is 1, the input is 1620 malformed. 1622 An example correspondence between unencoded and encoded values 1623 follows. The byte sequence below encodes into the string below, 1624 which when decoded, reproduces the byte sequence. 1625 3 236 255 224 193 1626 A-z_4ME 1628 Appendix D. Acknowledgements 1630 Solutions for signing JSON content were previously explored by Magic 1631 Signatures [MagicSignatures], JSON Simple Sign [JSS], and Canvas 1632 Applications [CanvasApp], all of which influenced this draft. Dirk 1633 Balfanz, Yaron Y. Goland, John Panzer, and Paul Tarjan all made 1634 significant contributions to the design of this specification. 1636 Thanks to Axel Nennker for his early implementation and feedback on 1637 the JWS and JWE specifications. 1639 Appendix E. Document History 1641 [[ to be removed by the RFC editor before publication as an RFC ]] 1643 -04 1645 o Completed JSON Security Considerations section, including 1646 considerations about rejecting input with duplicate member names. 1648 o Completed security considerations on the use of a SHA-1 hash when 1649 computing "x5t" (x.509 certificate thumbprint) values. 1651 o Refer to the registries as the primary sources of defined values 1652 and then secondarily reference the sections defining the initial 1653 contents of the registries. 1655 o Normatively reference XML DSIG 2.0 [W3C.CR-xmldsig-core2-20120124] 1656 for its security considerations. 1658 o Added this language to Registration Templates: "This name is case 1659 sensitive. Names that match other registered names in a case 1660 insensitive manner SHOULD NOT be accepted." 1662 o Reference draft-jones-jose-jws-json-serialization instead of 1663 draft-jones-json-web-signature-json-serialization. to 1665 o Described additional open issues. 1667 o Applied editorial suggestions. 1669 -03 1671 o Added the "cty" (content type) header parameter for declaring type 1672 information about the secured content, as opposed to the "typ" 1673 (type) header parameter, which declares type information about 1674 this object. 1676 o Added "Collision Resistant Namespace" to the terminology section. 1678 o Reference ITU.X690.1994 for DER encoding. 1680 o Added an example JWS using ECDSA P-521 SHA-512. This has 1681 particular illustrative value because of the use of the 521 bit 1682 integers in the key and signature values. This is also an example 1683 in which the payload is not a base64url encoded JSON object. 1685 o Added an example "x5c" value. 1687 o No longer say "the UTF-8 representation of the JWS Secured Input 1688 (which is the same as the ASCII representation)". Just call it 1689 "the ASCII representation of the JWS Secured Input". 1691 o Added Registration Template sections for defined registries. 1693 o Added Registry Contents sections to populate registry values. 1695 o Changed name of the JSON Web Signature and Encryption "typ" Values 1696 registry to be the JSON Web Signature and Encryption Type Values 1697 registry, since it is used for more than just values of the "typ" 1698 parameter. 1700 o Moved registries JSON Web Signature and Encryption Header 1701 Parameters and JSON Web Signature and Encryption Type Values to 1702 the JWS specification. 1704 o Numerous editorial improvements. 1706 -02 1708 o Clarified that it is an error when a "kid" value is included and 1709 no matching key is found. 1711 o Removed assumption that "kid" (key ID) can only refer to an 1712 asymmetric key. 1714 o Clarified that JWSs with duplicate Header Parameter Names MUST be 1715 rejected. 1717 o Clarified the relationship between "typ" header parameter values 1718 and MIME types. 1720 o Registered application/jws MIME type and "JWS" typ header 1721 parameter value. 1723 o Simplified JWK terminology to get replace the "JWK Key Object" and 1724 "JWK Container Object" terms with simply "JSON Web Key (JWK)" and 1725 "JSON Web Key Set (JWK Set)" and to eliminate potential confusion 1726 between single keys and sets of keys. As part of this change, the 1727 header parameter name for a public key value was changed from 1728 "jpk" (JSON Public Key) to "jwk" (JSON Web Key). 1730 o Added suggestion on defining additional header parameters such as 1731 "x5t#S256" in the future for certificate thumbprints using hash 1732 algorithms other than SHA-1. 1734 o Specify RFC 2818 server identity validation, rather than RFC 6125 1735 (paralleling the same decision in the OAuth specs). 1737 o Generalized language to refer to Message Authentication Codes 1738 (MACs) rather than Hash-based Message Authentication Codes (HMACs) 1739 unless in a context specific to HMAC algorithms. 1741 o Reformatted to give each header parameter its own section heading. 1743 -01 1745 o Moved definition of Plaintext JWSs (using "alg":"none") here from 1746 the JWT specification since this functionality is likely to be 1747 useful in more contexts that just for JWTs. 1749 o Added "jpk" and "x5c" header parameters for including JWK public 1750 keys and X.509 certificate chains directly in the header. 1752 o Clarified that this specification is defining the JWS Compact 1753 Serialization. Referenced the new JWS-JS spec, which defines the 1754 JWS JSON Serialization. 1756 o Added text "New header parameters should be introduced sparingly 1757 since an implementation that does not understand a parameter MUST 1758 reject the JWS". 1760 o Clarified that the order of the creation and validation steps is 1761 not significant in cases where there are no dependencies between 1762 the inputs and outputs of the steps. 1764 o Changed "no canonicalization is performed" to "no canonicalization 1765 need be performed". 1767 o Corrected the Magic Signatures reference. 1769 o Made other editorial improvements suggested by JOSE working group 1770 participants. 1772 -00 1774 o Created the initial IETF draft based upon 1775 draft-jones-json-web-signature-04 with no normative changes. 1777 o Changed terminology to no longer call both digital signatures and 1778 HMACs "signatures". 1780 Authors' Addresses 1782 Michael B. Jones 1783 Microsoft 1785 Email: mbj@microsoft.com 1786 URI: http://self-issued.info/ 1788 John Bradley 1789 Ping Identity 1791 Email: ve7jtb@ve7jtb.com 1793 Nat Sakimura 1794 Nomura Research Institute 1796 Email: n-sakimura@nri.co.jp