1// Copyright 2009 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5// Package x509 parses X.509-encoded keys and certificates. 6package x509 7 8import ( 9 "bytes" 10 "crypto" 11 "crypto/dsa" 12 "crypto/ecdsa" 13 "crypto/ed25519" 14 "crypto/elliptic" 15 "crypto/rsa" 16 "crypto/sha1" 17 "crypto/x509/pkix" 18 "encoding/asn1" 19 "encoding/pem" 20 "errors" 21 "fmt" 22 "io" 23 "math/big" 24 "net" 25 "net/url" 26 "strconv" 27 "strings" 28 "time" 29 "unicode" 30 31 // Explicitly import these for their crypto.RegisterHash init side-effects. 32 // Keep these as blank imports, even if they're imported above. 33 _ "crypto/sha1" 34 _ "crypto/sha256" 35 _ "crypto/sha512" 36 37 "golang.org/x/crypto/cryptobyte" 38 cryptobyte_asn1 "golang.org/x/crypto/cryptobyte/asn1" 39) 40 41// pkixPublicKey reflects a PKIX public key structure. See SubjectPublicKeyInfo 42// in RFC 3280. 43type pkixPublicKey struct { 44 Algo pkix.AlgorithmIdentifier 45 BitString asn1.BitString 46} 47 48// ParsePKIXPublicKey parses a public key in PKIX, ASN.1 DER form. 49// The encoded public key is a SubjectPublicKeyInfo structure 50// (see RFC 5280, Section 4.1). 51// 52// It returns a *rsa.PublicKey, *dsa.PublicKey, *ecdsa.PublicKey, or 53// ed25519.PublicKey. More types might be supported in the future. 54// 55// This kind of key is commonly encoded in PEM blocks of type "PUBLIC KEY". 56func ParsePKIXPublicKey(derBytes []byte) (pub interface{}, err error) { 57 var pki publicKeyInfo 58 if rest, err := asn1.Unmarshal(derBytes, &pki); err != nil { 59 if _, err := asn1.Unmarshal(derBytes, &pkcs1PublicKey{}); err == nil { 60 return nil, errors.New("x509: failed to parse public key (use ParsePKCS1PublicKey instead for this key format)") 61 } 62 return nil, err 63 } else if len(rest) != 0 { 64 return nil, errors.New("x509: trailing data after ASN.1 of public-key") 65 } 66 algo := getPublicKeyAlgorithmFromOID(pki.Algorithm.Algorithm) 67 if algo == UnknownPublicKeyAlgorithm { 68 return nil, errors.New("x509: unknown public key algorithm") 69 } 70 return parsePublicKey(algo, &pki) 71} 72 73func marshalPublicKey(pub interface{}) (publicKeyBytes []byte, publicKeyAlgorithm pkix.AlgorithmIdentifier, err error) { 74 switch pub := pub.(type) { 75 case *rsa.PublicKey: 76 publicKeyBytes, err = asn1.Marshal(pkcs1PublicKey{ 77 N: pub.N, 78 E: pub.E, 79 }) 80 if err != nil { 81 return nil, pkix.AlgorithmIdentifier{}, err 82 } 83 publicKeyAlgorithm.Algorithm = oidPublicKeyRSA 84 // This is a NULL parameters value which is required by 85 // RFC 3279, Section 2.3.1. 86 publicKeyAlgorithm.Parameters = asn1.NullRawValue 87 case *ecdsa.PublicKey: 88 publicKeyBytes = elliptic.Marshal(pub.Curve, pub.X, pub.Y) 89 oid, ok := oidFromNamedCurve(pub.Curve) 90 if !ok { 91 return nil, pkix.AlgorithmIdentifier{}, errors.New("x509: unsupported elliptic curve") 92 } 93 publicKeyAlgorithm.Algorithm = oidPublicKeyECDSA 94 var paramBytes []byte 95 paramBytes, err = asn1.Marshal(oid) 96 if err != nil { 97 return 98 } 99 publicKeyAlgorithm.Parameters.FullBytes = paramBytes 100 case ed25519.PublicKey: 101 publicKeyBytes = pub 102 publicKeyAlgorithm.Algorithm = oidPublicKeyEd25519 103 default: 104 return nil, pkix.AlgorithmIdentifier{}, fmt.Errorf("x509: unsupported public key type: %T", pub) 105 } 106 107 return publicKeyBytes, publicKeyAlgorithm, nil 108} 109 110// MarshalPKIXPublicKey converts a public key to PKIX, ASN.1 DER form. 111// The encoded public key is a SubjectPublicKeyInfo structure 112// (see RFC 5280, Section 4.1). 113// 114// The following key types are currently supported: *rsa.PublicKey, *ecdsa.PublicKey 115// and ed25519.PublicKey. Unsupported key types result in an error. 116// 117// This kind of key is commonly encoded in PEM blocks of type "PUBLIC KEY". 118func MarshalPKIXPublicKey(pub interface{}) ([]byte, error) { 119 var publicKeyBytes []byte 120 var publicKeyAlgorithm pkix.AlgorithmIdentifier 121 var err error 122 123 if publicKeyBytes, publicKeyAlgorithm, err = marshalPublicKey(pub); err != nil { 124 return nil, err 125 } 126 127 pkix := pkixPublicKey{ 128 Algo: publicKeyAlgorithm, 129 BitString: asn1.BitString{ 130 Bytes: publicKeyBytes, 131 BitLength: 8 * len(publicKeyBytes), 132 }, 133 } 134 135 ret, _ := asn1.Marshal(pkix) 136 return ret, nil 137} 138 139// These structures reflect the ASN.1 structure of X.509 certificates.: 140 141type certificate struct { 142 Raw asn1.RawContent 143 TBSCertificate tbsCertificate 144 SignatureAlgorithm pkix.AlgorithmIdentifier 145 SignatureValue asn1.BitString 146} 147 148type tbsCertificate struct { 149 Raw asn1.RawContent 150 Version int `asn1:"optional,explicit,default:0,tag:0"` 151 SerialNumber *big.Int 152 SignatureAlgorithm pkix.AlgorithmIdentifier 153 Issuer asn1.RawValue 154 Validity validity 155 Subject asn1.RawValue 156 PublicKey publicKeyInfo 157 UniqueId asn1.BitString `asn1:"optional,tag:1"` 158 SubjectUniqueId asn1.BitString `asn1:"optional,tag:2"` 159 Extensions []pkix.Extension `asn1:"optional,explicit,tag:3"` 160} 161 162type dsaAlgorithmParameters struct { 163 P, Q, G *big.Int 164} 165 166type validity struct { 167 NotBefore, NotAfter time.Time 168} 169 170type publicKeyInfo struct { 171 Raw asn1.RawContent 172 Algorithm pkix.AlgorithmIdentifier 173 PublicKey asn1.BitString 174} 175 176// RFC 5280, 4.2.1.1 177type authKeyId struct { 178 Id []byte `asn1:"optional,tag:0"` 179} 180 181type SignatureAlgorithm int 182 183const ( 184 UnknownSignatureAlgorithm SignatureAlgorithm = iota 185 186 MD2WithRSA // Unsupported. 187 MD5WithRSA // Only supported for signing, not verification. 188 SHA1WithRSA 189 SHA256WithRSA 190 SHA384WithRSA 191 SHA512WithRSA 192 DSAWithSHA1 // Unsupported. 193 DSAWithSHA256 // Unsupported. 194 ECDSAWithSHA1 195 ECDSAWithSHA256 196 ECDSAWithSHA384 197 ECDSAWithSHA512 198 SHA256WithRSAPSS 199 SHA384WithRSAPSS 200 SHA512WithRSAPSS 201 PureEd25519 202) 203 204func (algo SignatureAlgorithm) isRSAPSS() bool { 205 switch algo { 206 case SHA256WithRSAPSS, SHA384WithRSAPSS, SHA512WithRSAPSS: 207 return true 208 default: 209 return false 210 } 211} 212 213func (algo SignatureAlgorithm) String() string { 214 for _, details := range signatureAlgorithmDetails { 215 if details.algo == algo { 216 return details.name 217 } 218 } 219 return strconv.Itoa(int(algo)) 220} 221 222type PublicKeyAlgorithm int 223 224const ( 225 UnknownPublicKeyAlgorithm PublicKeyAlgorithm = iota 226 RSA 227 DSA // Unsupported. 228 ECDSA 229 Ed25519 230) 231 232var publicKeyAlgoName = [...]string{ 233 RSA: "RSA", 234 DSA: "DSA", 235 ECDSA: "ECDSA", 236 Ed25519: "Ed25519", 237} 238 239func (algo PublicKeyAlgorithm) String() string { 240 if 0 < algo && int(algo) < len(publicKeyAlgoName) { 241 return publicKeyAlgoName[algo] 242 } 243 return strconv.Itoa(int(algo)) 244} 245 246// OIDs for signature algorithms 247// 248// pkcs-1 OBJECT IDENTIFIER ::= { 249// iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 1 } 250// 251// 252// RFC 3279 2.2.1 RSA Signature Algorithms 253// 254// md2WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 2 } 255// 256// md5WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 4 } 257// 258// sha-1WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 5 } 259// 260// dsaWithSha1 OBJECT IDENTIFIER ::= { 261// iso(1) member-body(2) us(840) x9-57(10040) x9cm(4) 3 } 262// 263// RFC 3279 2.2.3 ECDSA Signature Algorithm 264// 265// ecdsa-with-SHA1 OBJECT IDENTIFIER ::= { 266// iso(1) member-body(2) us(840) ansi-x962(10045) 267// signatures(4) ecdsa-with-SHA1(1)} 268// 269// 270// RFC 4055 5 PKCS #1 Version 1.5 271// 272// sha256WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 11 } 273// 274// sha384WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 12 } 275// 276// sha512WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 13 } 277// 278// 279// RFC 5758 3.1 DSA Signature Algorithms 280// 281// dsaWithSha256 OBJECT IDENTIFIER ::= { 282// joint-iso-ccitt(2) country(16) us(840) organization(1) gov(101) 283// csor(3) algorithms(4) id-dsa-with-sha2(3) 2} 284// 285// RFC 5758 3.2 ECDSA Signature Algorithm 286// 287// ecdsa-with-SHA256 OBJECT IDENTIFIER ::= { iso(1) member-body(2) 288// us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 2 } 289// 290// ecdsa-with-SHA384 OBJECT IDENTIFIER ::= { iso(1) member-body(2) 291// us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 3 } 292// 293// ecdsa-with-SHA512 OBJECT IDENTIFIER ::= { iso(1) member-body(2) 294// us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 4 } 295// 296// 297// RFC 8410 3 Curve25519 and Curve448 Algorithm Identifiers 298// 299// id-Ed25519 OBJECT IDENTIFIER ::= { 1 3 101 112 } 300 301var ( 302 oidSignatureMD2WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 2} 303 oidSignatureMD5WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 4} 304 oidSignatureSHA1WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 5} 305 oidSignatureSHA256WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 11} 306 oidSignatureSHA384WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 12} 307 oidSignatureSHA512WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 13} 308 oidSignatureRSAPSS = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 10} 309 oidSignatureDSAWithSHA1 = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 3} 310 oidSignatureDSAWithSHA256 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 3, 2} 311 oidSignatureECDSAWithSHA1 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 1} 312 oidSignatureECDSAWithSHA256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 2} 313 oidSignatureECDSAWithSHA384 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 3} 314 oidSignatureECDSAWithSHA512 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 4} 315 oidSignatureEd25519 = asn1.ObjectIdentifier{1, 3, 101, 112} 316 317 oidSHA256 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 1} 318 oidSHA384 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 2} 319 oidSHA512 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 3} 320 321 oidMGF1 = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 8} 322 323 // oidISOSignatureSHA1WithRSA means the same as oidSignatureSHA1WithRSA 324 // but it's specified by ISO. Microsoft's makecert.exe has been known 325 // to produce certificates with this OID. 326 oidISOSignatureSHA1WithRSA = asn1.ObjectIdentifier{1, 3, 14, 3, 2, 29} 327) 328 329var signatureAlgorithmDetails = []struct { 330 algo SignatureAlgorithm 331 name string 332 oid asn1.ObjectIdentifier 333 pubKeyAlgo PublicKeyAlgorithm 334 hash crypto.Hash 335}{ 336 {MD2WithRSA, "MD2-RSA", oidSignatureMD2WithRSA, RSA, crypto.Hash(0) /* no value for MD2 */}, 337 {MD5WithRSA, "MD5-RSA", oidSignatureMD5WithRSA, RSA, crypto.MD5}, 338 {SHA1WithRSA, "SHA1-RSA", oidSignatureSHA1WithRSA, RSA, crypto.SHA1}, 339 {SHA1WithRSA, "SHA1-RSA", oidISOSignatureSHA1WithRSA, RSA, crypto.SHA1}, 340 {SHA256WithRSA, "SHA256-RSA", oidSignatureSHA256WithRSA, RSA, crypto.SHA256}, 341 {SHA384WithRSA, "SHA384-RSA", oidSignatureSHA384WithRSA, RSA, crypto.SHA384}, 342 {SHA512WithRSA, "SHA512-RSA", oidSignatureSHA512WithRSA, RSA, crypto.SHA512}, 343 {SHA256WithRSAPSS, "SHA256-RSAPSS", oidSignatureRSAPSS, RSA, crypto.SHA256}, 344 {SHA384WithRSAPSS, "SHA384-RSAPSS", oidSignatureRSAPSS, RSA, crypto.SHA384}, 345 {SHA512WithRSAPSS, "SHA512-RSAPSS", oidSignatureRSAPSS, RSA, crypto.SHA512}, 346 {DSAWithSHA1, "DSA-SHA1", oidSignatureDSAWithSHA1, DSA, crypto.SHA1}, 347 {DSAWithSHA256, "DSA-SHA256", oidSignatureDSAWithSHA256, DSA, crypto.SHA256}, 348 {ECDSAWithSHA1, "ECDSA-SHA1", oidSignatureECDSAWithSHA1, ECDSA, crypto.SHA1}, 349 {ECDSAWithSHA256, "ECDSA-SHA256", oidSignatureECDSAWithSHA256, ECDSA, crypto.SHA256}, 350 {ECDSAWithSHA384, "ECDSA-SHA384", oidSignatureECDSAWithSHA384, ECDSA, crypto.SHA384}, 351 {ECDSAWithSHA512, "ECDSA-SHA512", oidSignatureECDSAWithSHA512, ECDSA, crypto.SHA512}, 352 {PureEd25519, "Ed25519", oidSignatureEd25519, Ed25519, crypto.Hash(0) /* no pre-hashing */}, 353} 354 355// hashToPSSParameters contains the DER encoded RSA PSS parameters for the 356// SHA256, SHA384, and SHA512 hashes as defined in RFC 3447, Appendix A.2.3. 357// The parameters contain the following values: 358// * hashAlgorithm contains the associated hash identifier with NULL parameters 359// * maskGenAlgorithm always contains the default mgf1SHA1 identifier 360// * saltLength contains the length of the associated hash 361// * trailerField always contains the default trailerFieldBC value 362var hashToPSSParameters = map[crypto.Hash]asn1.RawValue{ 363 crypto.SHA256: asn1.RawValue{FullBytes: []byte{48, 52, 160, 15, 48, 13, 6, 9, 96, 134, 72, 1, 101, 3, 4, 2, 1, 5, 0, 161, 28, 48, 26, 6, 9, 42, 134, 72, 134, 247, 13, 1, 1, 8, 48, 13, 6, 9, 96, 134, 72, 1, 101, 3, 4, 2, 1, 5, 0, 162, 3, 2, 1, 32}}, 364 crypto.SHA384: asn1.RawValue{FullBytes: []byte{48, 52, 160, 15, 48, 13, 6, 9, 96, 134, 72, 1, 101, 3, 4, 2, 2, 5, 0, 161, 28, 48, 26, 6, 9, 42, 134, 72, 134, 247, 13, 1, 1, 8, 48, 13, 6, 9, 96, 134, 72, 1, 101, 3, 4, 2, 2, 5, 0, 162, 3, 2, 1, 48}}, 365 crypto.SHA512: asn1.RawValue{FullBytes: []byte{48, 52, 160, 15, 48, 13, 6, 9, 96, 134, 72, 1, 101, 3, 4, 2, 3, 5, 0, 161, 28, 48, 26, 6, 9, 42, 134, 72, 134, 247, 13, 1, 1, 8, 48, 13, 6, 9, 96, 134, 72, 1, 101, 3, 4, 2, 3, 5, 0, 162, 3, 2, 1, 64}}, 366} 367 368// pssParameters reflects the parameters in an AlgorithmIdentifier that 369// specifies RSA PSS. See RFC 3447, Appendix A.2.3. 370type pssParameters struct { 371 // The following three fields are not marked as 372 // optional because the default values specify SHA-1, 373 // which is no longer suitable for use in signatures. 374 Hash pkix.AlgorithmIdentifier `asn1:"explicit,tag:0"` 375 MGF pkix.AlgorithmIdentifier `asn1:"explicit,tag:1"` 376 SaltLength int `asn1:"explicit,tag:2"` 377 TrailerField int `asn1:"optional,explicit,tag:3,default:1"` 378} 379 380func getSignatureAlgorithmFromAI(ai pkix.AlgorithmIdentifier) SignatureAlgorithm { 381 if ai.Algorithm.Equal(oidSignatureEd25519) { 382 // RFC 8410, Section 3 383 // > For all of the OIDs, the parameters MUST be absent. 384 if len(ai.Parameters.FullBytes) != 0 { 385 return UnknownSignatureAlgorithm 386 } 387 } 388 389 if !ai.Algorithm.Equal(oidSignatureRSAPSS) { 390 for _, details := range signatureAlgorithmDetails { 391 if ai.Algorithm.Equal(details.oid) { 392 return details.algo 393 } 394 } 395 return UnknownSignatureAlgorithm 396 } 397 398 // RSA PSS is special because it encodes important parameters 399 // in the Parameters. 400 401 var params pssParameters 402 if _, err := asn1.Unmarshal(ai.Parameters.FullBytes, ¶ms); err != nil { 403 return UnknownSignatureAlgorithm 404 } 405 406 var mgf1HashFunc pkix.AlgorithmIdentifier 407 if _, err := asn1.Unmarshal(params.MGF.Parameters.FullBytes, &mgf1HashFunc); err != nil { 408 return UnknownSignatureAlgorithm 409 } 410 411 // PSS is greatly overburdened with options. This code forces them into 412 // three buckets by requiring that the MGF1 hash function always match the 413 // message hash function (as recommended in RFC 3447, Section 8.1), that the 414 // salt length matches the hash length, and that the trailer field has the 415 // default value. 416 if (len(params.Hash.Parameters.FullBytes) != 0 && !bytes.Equal(params.Hash.Parameters.FullBytes, asn1.NullBytes)) || 417 !params.MGF.Algorithm.Equal(oidMGF1) || 418 !mgf1HashFunc.Algorithm.Equal(params.Hash.Algorithm) || 419 (len(mgf1HashFunc.Parameters.FullBytes) != 0 && !bytes.Equal(mgf1HashFunc.Parameters.FullBytes, asn1.NullBytes)) || 420 params.TrailerField != 1 { 421 return UnknownSignatureAlgorithm 422 } 423 424 switch { 425 case params.Hash.Algorithm.Equal(oidSHA256) && params.SaltLength == 32: 426 return SHA256WithRSAPSS 427 case params.Hash.Algorithm.Equal(oidSHA384) && params.SaltLength == 48: 428 return SHA384WithRSAPSS 429 case params.Hash.Algorithm.Equal(oidSHA512) && params.SaltLength == 64: 430 return SHA512WithRSAPSS 431 } 432 433 return UnknownSignatureAlgorithm 434} 435 436// RFC 3279, 2.3 Public Key Algorithms 437// 438// pkcs-1 OBJECT IDENTIFIER ::== { iso(1) member-body(2) us(840) 439// rsadsi(113549) pkcs(1) 1 } 440// 441// rsaEncryption OBJECT IDENTIFIER ::== { pkcs1-1 1 } 442// 443// id-dsa OBJECT IDENTIFIER ::== { iso(1) member-body(2) us(840) 444// x9-57(10040) x9cm(4) 1 } 445// 446// RFC 5480, 2.1.1 Unrestricted Algorithm Identifier and Parameters 447// 448// id-ecPublicKey OBJECT IDENTIFIER ::= { 449// iso(1) member-body(2) us(840) ansi-X9-62(10045) keyType(2) 1 } 450var ( 451 oidPublicKeyRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 1} 452 oidPublicKeyDSA = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 1} 453 oidPublicKeyECDSA = asn1.ObjectIdentifier{1, 2, 840, 10045, 2, 1} 454 oidPublicKeyEd25519 = oidSignatureEd25519 455) 456 457func getPublicKeyAlgorithmFromOID(oid asn1.ObjectIdentifier) PublicKeyAlgorithm { 458 switch { 459 case oid.Equal(oidPublicKeyRSA): 460 return RSA 461 case oid.Equal(oidPublicKeyDSA): 462 return DSA 463 case oid.Equal(oidPublicKeyECDSA): 464 return ECDSA 465 case oid.Equal(oidPublicKeyEd25519): 466 return Ed25519 467 } 468 return UnknownPublicKeyAlgorithm 469} 470 471// RFC 5480, 2.1.1.1. Named Curve 472// 473// secp224r1 OBJECT IDENTIFIER ::= { 474// iso(1) identified-organization(3) certicom(132) curve(0) 33 } 475// 476// secp256r1 OBJECT IDENTIFIER ::= { 477// iso(1) member-body(2) us(840) ansi-X9-62(10045) curves(3) 478// prime(1) 7 } 479// 480// secp384r1 OBJECT IDENTIFIER ::= { 481// iso(1) identified-organization(3) certicom(132) curve(0) 34 } 482// 483// secp521r1 OBJECT IDENTIFIER ::= { 484// iso(1) identified-organization(3) certicom(132) curve(0) 35 } 485// 486// NB: secp256r1 is equivalent to prime256v1 487var ( 488 oidNamedCurveP224 = asn1.ObjectIdentifier{1, 3, 132, 0, 33} 489 oidNamedCurveP256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 3, 1, 7} 490 oidNamedCurveP384 = asn1.ObjectIdentifier{1, 3, 132, 0, 34} 491 oidNamedCurveP521 = asn1.ObjectIdentifier{1, 3, 132, 0, 35} 492) 493 494func namedCurveFromOID(oid asn1.ObjectIdentifier) elliptic.Curve { 495 switch { 496 case oid.Equal(oidNamedCurveP224): 497 return elliptic.P224() 498 case oid.Equal(oidNamedCurveP256): 499 return elliptic.P256() 500 case oid.Equal(oidNamedCurveP384): 501 return elliptic.P384() 502 case oid.Equal(oidNamedCurveP521): 503 return elliptic.P521() 504 } 505 return nil 506} 507 508func oidFromNamedCurve(curve elliptic.Curve) (asn1.ObjectIdentifier, bool) { 509 switch curve { 510 case elliptic.P224(): 511 return oidNamedCurveP224, true 512 case elliptic.P256(): 513 return oidNamedCurveP256, true 514 case elliptic.P384(): 515 return oidNamedCurveP384, true 516 case elliptic.P521(): 517 return oidNamedCurveP521, true 518 } 519 520 return nil, false 521} 522 523// KeyUsage represents the set of actions that are valid for a given key. It's 524// a bitmap of the KeyUsage* constants. 525type KeyUsage int 526 527const ( 528 KeyUsageDigitalSignature KeyUsage = 1 << iota 529 KeyUsageContentCommitment 530 KeyUsageKeyEncipherment 531 KeyUsageDataEncipherment 532 KeyUsageKeyAgreement 533 KeyUsageCertSign 534 KeyUsageCRLSign 535 KeyUsageEncipherOnly 536 KeyUsageDecipherOnly 537) 538 539// RFC 5280, 4.2.1.12 Extended Key Usage 540// 541// anyExtendedKeyUsage OBJECT IDENTIFIER ::= { id-ce-extKeyUsage 0 } 542// 543// id-kp OBJECT IDENTIFIER ::= { id-pkix 3 } 544// 545// id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 } 546// id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 } 547// id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 } 548// id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 } 549// id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 } 550// id-kp-OCSPSigning OBJECT IDENTIFIER ::= { id-kp 9 } 551var ( 552 oidExtKeyUsageAny = asn1.ObjectIdentifier{2, 5, 29, 37, 0} 553 oidExtKeyUsageServerAuth = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 1} 554 oidExtKeyUsageClientAuth = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 2} 555 oidExtKeyUsageCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 3} 556 oidExtKeyUsageEmailProtection = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 4} 557 oidExtKeyUsageIPSECEndSystem = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 5} 558 oidExtKeyUsageIPSECTunnel = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 6} 559 oidExtKeyUsageIPSECUser = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 7} 560 oidExtKeyUsageTimeStamping = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 8} 561 oidExtKeyUsageOCSPSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 9} 562 oidExtKeyUsageMicrosoftServerGatedCrypto = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 10, 3, 3} 563 oidExtKeyUsageNetscapeServerGatedCrypto = asn1.ObjectIdentifier{2, 16, 840, 1, 113730, 4, 1} 564 oidExtKeyUsageMicrosoftCommercialCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 2, 1, 22} 565 oidExtKeyUsageMicrosoftKernelCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 61, 1, 1} 566) 567 568// ExtKeyUsage represents an extended set of actions that are valid for a given key. 569// Each of the ExtKeyUsage* constants define a unique action. 570type ExtKeyUsage int 571 572const ( 573 ExtKeyUsageAny ExtKeyUsage = iota 574 ExtKeyUsageServerAuth 575 ExtKeyUsageClientAuth 576 ExtKeyUsageCodeSigning 577 ExtKeyUsageEmailProtection 578 ExtKeyUsageIPSECEndSystem 579 ExtKeyUsageIPSECTunnel 580 ExtKeyUsageIPSECUser 581 ExtKeyUsageTimeStamping 582 ExtKeyUsageOCSPSigning 583 ExtKeyUsageMicrosoftServerGatedCrypto 584 ExtKeyUsageNetscapeServerGatedCrypto 585 ExtKeyUsageMicrosoftCommercialCodeSigning 586 ExtKeyUsageMicrosoftKernelCodeSigning 587) 588 589// extKeyUsageOIDs contains the mapping between an ExtKeyUsage and its OID. 590var extKeyUsageOIDs = []struct { 591 extKeyUsage ExtKeyUsage 592 oid asn1.ObjectIdentifier 593}{ 594 {ExtKeyUsageAny, oidExtKeyUsageAny}, 595 {ExtKeyUsageServerAuth, oidExtKeyUsageServerAuth}, 596 {ExtKeyUsageClientAuth, oidExtKeyUsageClientAuth}, 597 {ExtKeyUsageCodeSigning, oidExtKeyUsageCodeSigning}, 598 {ExtKeyUsageEmailProtection, oidExtKeyUsageEmailProtection}, 599 {ExtKeyUsageIPSECEndSystem, oidExtKeyUsageIPSECEndSystem}, 600 {ExtKeyUsageIPSECTunnel, oidExtKeyUsageIPSECTunnel}, 601 {ExtKeyUsageIPSECUser, oidExtKeyUsageIPSECUser}, 602 {ExtKeyUsageTimeStamping, oidExtKeyUsageTimeStamping}, 603 {ExtKeyUsageOCSPSigning, oidExtKeyUsageOCSPSigning}, 604 {ExtKeyUsageMicrosoftServerGatedCrypto, oidExtKeyUsageMicrosoftServerGatedCrypto}, 605 {ExtKeyUsageNetscapeServerGatedCrypto, oidExtKeyUsageNetscapeServerGatedCrypto}, 606 {ExtKeyUsageMicrosoftCommercialCodeSigning, oidExtKeyUsageMicrosoftCommercialCodeSigning}, 607 {ExtKeyUsageMicrosoftKernelCodeSigning, oidExtKeyUsageMicrosoftKernelCodeSigning}, 608} 609 610func extKeyUsageFromOID(oid asn1.ObjectIdentifier) (eku ExtKeyUsage, ok bool) { 611 for _, pair := range extKeyUsageOIDs { 612 if oid.Equal(pair.oid) { 613 return pair.extKeyUsage, true 614 } 615 } 616 return 617} 618 619func oidFromExtKeyUsage(eku ExtKeyUsage) (oid asn1.ObjectIdentifier, ok bool) { 620 for _, pair := range extKeyUsageOIDs { 621 if eku == pair.extKeyUsage { 622 return pair.oid, true 623 } 624 } 625 return 626} 627 628// A Certificate represents an X.509 certificate. 629type Certificate struct { 630 Raw []byte // Complete ASN.1 DER content (certificate, signature algorithm and signature). 631 RawTBSCertificate []byte // Certificate part of raw ASN.1 DER content. 632 RawSubjectPublicKeyInfo []byte // DER encoded SubjectPublicKeyInfo. 633 RawSubject []byte // DER encoded Subject 634 RawIssuer []byte // DER encoded Issuer 635 636 Signature []byte 637 SignatureAlgorithm SignatureAlgorithm 638 639 PublicKeyAlgorithm PublicKeyAlgorithm 640 PublicKey interface{} 641 642 Version int 643 SerialNumber *big.Int 644 Issuer pkix.Name 645 Subject pkix.Name 646 NotBefore, NotAfter time.Time // Validity bounds. 647 KeyUsage KeyUsage 648 649 // Extensions contains raw X.509 extensions. When parsing certificates, 650 // this can be used to extract non-critical extensions that are not 651 // parsed by this package. When marshaling certificates, the Extensions 652 // field is ignored, see ExtraExtensions. 653 Extensions []pkix.Extension 654 655 // ExtraExtensions contains extensions to be copied, raw, into any 656 // marshaled certificates. Values override any extensions that would 657 // otherwise be produced based on the other fields. The ExtraExtensions 658 // field is not populated when parsing certificates, see Extensions. 659 ExtraExtensions []pkix.Extension 660 661 // UnhandledCriticalExtensions contains a list of extension IDs that 662 // were not (fully) processed when parsing. Verify will fail if this 663 // slice is non-empty, unless verification is delegated to an OS 664 // library which understands all the critical extensions. 665 // 666 // Users can access these extensions using Extensions and can remove 667 // elements from this slice if they believe that they have been 668 // handled. 669 UnhandledCriticalExtensions []asn1.ObjectIdentifier 670 671 ExtKeyUsage []ExtKeyUsage // Sequence of extended key usages. 672 UnknownExtKeyUsage []asn1.ObjectIdentifier // Encountered extended key usages unknown to this package. 673 674 // BasicConstraintsValid indicates whether IsCA, MaxPathLen, 675 // and MaxPathLenZero are valid. 676 BasicConstraintsValid bool 677 IsCA bool 678 679 // MaxPathLen and MaxPathLenZero indicate the presence and 680 // value of the BasicConstraints' "pathLenConstraint". 681 // 682 // When parsing a certificate, a positive non-zero MaxPathLen 683 // means that the field was specified, -1 means it was unset, 684 // and MaxPathLenZero being true mean that the field was 685 // explicitly set to zero. The case of MaxPathLen==0 with MaxPathLenZero==false 686 // should be treated equivalent to -1 (unset). 687 // 688 // When generating a certificate, an unset pathLenConstraint 689 // can be requested with either MaxPathLen == -1 or using the 690 // zero value for both MaxPathLen and MaxPathLenZero. 691 MaxPathLen int 692 // MaxPathLenZero indicates that BasicConstraintsValid==true 693 // and MaxPathLen==0 should be interpreted as an actual 694 // maximum path length of zero. Otherwise, that combination is 695 // interpreted as MaxPathLen not being set. 696 MaxPathLenZero bool 697 698 SubjectKeyId []byte 699 AuthorityKeyId []byte 700 701 // RFC 5280, 4.2.2.1 (Authority Information Access) 702 OCSPServer []string 703 IssuingCertificateURL []string 704 705 // Subject Alternate Name values. (Note that these values may not be valid 706 // if invalid values were contained within a parsed certificate. For 707 // example, an element of DNSNames may not be a valid DNS domain name.) 708 DNSNames []string 709 EmailAddresses []string 710 IPAddresses []net.IP 711 URIs []*url.URL 712 713 // Name constraints 714 PermittedDNSDomainsCritical bool // if true then the name constraints are marked critical. 715 PermittedDNSDomains []string 716 ExcludedDNSDomains []string 717 PermittedIPRanges []*net.IPNet 718 ExcludedIPRanges []*net.IPNet 719 PermittedEmailAddresses []string 720 ExcludedEmailAddresses []string 721 PermittedURIDomains []string 722 ExcludedURIDomains []string 723 724 // CRL Distribution Points 725 CRLDistributionPoints []string 726 727 PolicyIdentifiers []asn1.ObjectIdentifier 728} 729 730// ErrUnsupportedAlgorithm results from attempting to perform an operation that 731// involves algorithms that are not currently implemented. 732var ErrUnsupportedAlgorithm = errors.New("x509: cannot verify signature: algorithm unimplemented") 733 734// An InsecureAlgorithmError 735type InsecureAlgorithmError SignatureAlgorithm 736 737func (e InsecureAlgorithmError) Error() string { 738 return fmt.Sprintf("x509: cannot verify signature: insecure algorithm %v", SignatureAlgorithm(e)) 739} 740 741// ConstraintViolationError results when a requested usage is not permitted by 742// a certificate. For example: checking a signature when the public key isn't a 743// certificate signing key. 744type ConstraintViolationError struct{} 745 746func (ConstraintViolationError) Error() string { 747 return "x509: invalid signature: parent certificate cannot sign this kind of certificate" 748} 749 750func (c *Certificate) Equal(other *Certificate) bool { 751 if c == nil || other == nil { 752 return c == other 753 } 754 return bytes.Equal(c.Raw, other.Raw) 755} 756 757func (c *Certificate) hasSANExtension() bool { 758 return oidInExtensions(oidExtensionSubjectAltName, c.Extensions) 759} 760 761// CheckSignatureFrom verifies that the signature on c is a valid signature 762// from parent. 763func (c *Certificate) CheckSignatureFrom(parent *Certificate) error { 764 // RFC 5280, 4.2.1.9: 765 // "If the basic constraints extension is not present in a version 3 766 // certificate, or the extension is present but the cA boolean is not 767 // asserted, then the certified public key MUST NOT be used to verify 768 // certificate signatures." 769 if parent.Version == 3 && !parent.BasicConstraintsValid || 770 parent.BasicConstraintsValid && !parent.IsCA { 771 return ConstraintViolationError{} 772 } 773 774 if parent.KeyUsage != 0 && parent.KeyUsage&KeyUsageCertSign == 0 { 775 return ConstraintViolationError{} 776 } 777 778 if parent.PublicKeyAlgorithm == UnknownPublicKeyAlgorithm { 779 return ErrUnsupportedAlgorithm 780 } 781 782 // TODO(agl): don't ignore the path length constraint. 783 784 return parent.CheckSignature(c.SignatureAlgorithm, c.RawTBSCertificate, c.Signature) 785} 786 787// CheckSignature verifies that signature is a valid signature over signed from 788// c's public key. 789func (c *Certificate) CheckSignature(algo SignatureAlgorithm, signed, signature []byte) error { 790 return checkSignature(algo, signed, signature, c.PublicKey) 791} 792 793func (c *Certificate) hasNameConstraints() bool { 794 return oidInExtensions(oidExtensionNameConstraints, c.Extensions) 795} 796 797func (c *Certificate) getSANExtension() []byte { 798 for _, e := range c.Extensions { 799 if e.Id.Equal(oidExtensionSubjectAltName) { 800 return e.Value 801 } 802 } 803 return nil 804} 805 806func signaturePublicKeyAlgoMismatchError(expectedPubKeyAlgo PublicKeyAlgorithm, pubKey interface{}) error { 807 return fmt.Errorf("x509: signature algorithm specifies an %s public key, but have public key of type %T", expectedPubKeyAlgo.String(), pubKey) 808} 809 810// CheckSignature verifies that signature is a valid signature over signed from 811// a crypto.PublicKey. 812func checkSignature(algo SignatureAlgorithm, signed, signature []byte, publicKey crypto.PublicKey) (err error) { 813 var hashType crypto.Hash 814 var pubKeyAlgo PublicKeyAlgorithm 815 816 for _, details := range signatureAlgorithmDetails { 817 if details.algo == algo { 818 hashType = details.hash 819 pubKeyAlgo = details.pubKeyAlgo 820 } 821 } 822 823 switch hashType { 824 case crypto.Hash(0): 825 if pubKeyAlgo != Ed25519 { 826 return ErrUnsupportedAlgorithm 827 } 828 case crypto.MD5: 829 return InsecureAlgorithmError(algo) 830 default: 831 if !hashType.Available() { 832 return ErrUnsupportedAlgorithm 833 } 834 h := hashType.New() 835 h.Write(signed) 836 signed = h.Sum(nil) 837 } 838 839 switch pub := publicKey.(type) { 840 case *rsa.PublicKey: 841 if pubKeyAlgo != RSA { 842 return signaturePublicKeyAlgoMismatchError(pubKeyAlgo, pub) 843 } 844 if algo.isRSAPSS() { 845 return rsa.VerifyPSS(pub, hashType, signed, signature, &rsa.PSSOptions{SaltLength: rsa.PSSSaltLengthEqualsHash}) 846 } else { 847 return rsa.VerifyPKCS1v15(pub, hashType, signed, signature) 848 } 849 case *ecdsa.PublicKey: 850 if pubKeyAlgo != ECDSA { 851 return signaturePublicKeyAlgoMismatchError(pubKeyAlgo, pub) 852 } 853 if !ecdsa.VerifyASN1(pub, signed, signature) { 854 return errors.New("x509: ECDSA verification failure") 855 } 856 return 857 case ed25519.PublicKey: 858 if pubKeyAlgo != Ed25519 { 859 return signaturePublicKeyAlgoMismatchError(pubKeyAlgo, pub) 860 } 861 if !ed25519.Verify(pub, signed, signature) { 862 return errors.New("x509: Ed25519 verification failure") 863 } 864 return 865 } 866 return ErrUnsupportedAlgorithm 867} 868 869// CheckCRLSignature checks that the signature in crl is from c. 870func (c *Certificate) CheckCRLSignature(crl *pkix.CertificateList) error { 871 algo := getSignatureAlgorithmFromAI(crl.SignatureAlgorithm) 872 return c.CheckSignature(algo, crl.TBSCertList.Raw, crl.SignatureValue.RightAlign()) 873} 874 875type UnhandledCriticalExtension struct{} 876 877func (h UnhandledCriticalExtension) Error() string { 878 return "x509: unhandled critical extension" 879} 880 881type basicConstraints struct { 882 IsCA bool `asn1:"optional"` 883 MaxPathLen int `asn1:"optional,default:-1"` 884} 885 886// RFC 5280 4.2.1.4 887type policyInformation struct { 888 Policy asn1.ObjectIdentifier 889 // policyQualifiers omitted 890} 891 892const ( 893 nameTypeEmail = 1 894 nameTypeDNS = 2 895 nameTypeURI = 6 896 nameTypeIP = 7 897) 898 899// RFC 5280, 4.2.2.1 900type authorityInfoAccess struct { 901 Method asn1.ObjectIdentifier 902 Location asn1.RawValue 903} 904 905// RFC 5280, 4.2.1.14 906type distributionPoint struct { 907 DistributionPoint distributionPointName `asn1:"optional,tag:0"` 908 Reason asn1.BitString `asn1:"optional,tag:1"` 909 CRLIssuer asn1.RawValue `asn1:"optional,tag:2"` 910} 911 912type distributionPointName struct { 913 FullName []asn1.RawValue `asn1:"optional,tag:0"` 914 RelativeName pkix.RDNSequence `asn1:"optional,tag:1"` 915} 916 917func parsePublicKey(algo PublicKeyAlgorithm, keyData *publicKeyInfo) (interface{}, error) { 918 asn1Data := keyData.PublicKey.RightAlign() 919 switch algo { 920 case RSA: 921 // RSA public keys must have a NULL in the parameters. 922 // See RFC 3279, Section 2.3.1. 923 if !bytes.Equal(keyData.Algorithm.Parameters.FullBytes, asn1.NullBytes) { 924 return nil, errors.New("x509: RSA key missing NULL parameters") 925 } 926 927 p := new(pkcs1PublicKey) 928 rest, err := asn1.Unmarshal(asn1Data, p) 929 if err != nil { 930 return nil, err 931 } 932 if len(rest) != 0 { 933 return nil, errors.New("x509: trailing data after RSA public key") 934 } 935 936 if p.N.Sign() <= 0 { 937 return nil, errors.New("x509: RSA modulus is not a positive number") 938 } 939 if p.E <= 0 { 940 return nil, errors.New("x509: RSA public exponent is not a positive number") 941 } 942 943 pub := &rsa.PublicKey{ 944 E: p.E, 945 N: p.N, 946 } 947 return pub, nil 948 case DSA: 949 var p *big.Int 950 rest, err := asn1.Unmarshal(asn1Data, &p) 951 if err != nil { 952 return nil, err 953 } 954 if len(rest) != 0 { 955 return nil, errors.New("x509: trailing data after DSA public key") 956 } 957 paramsData := keyData.Algorithm.Parameters.FullBytes 958 params := new(dsaAlgorithmParameters) 959 rest, err = asn1.Unmarshal(paramsData, params) 960 if err != nil { 961 return nil, err 962 } 963 if len(rest) != 0 { 964 return nil, errors.New("x509: trailing data after DSA parameters") 965 } 966 if p.Sign() <= 0 || params.P.Sign() <= 0 || params.Q.Sign() <= 0 || params.G.Sign() <= 0 { 967 return nil, errors.New("x509: zero or negative DSA parameter") 968 } 969 pub := &dsa.PublicKey{ 970 Parameters: dsa.Parameters{ 971 P: params.P, 972 Q: params.Q, 973 G: params.G, 974 }, 975 Y: p, 976 } 977 return pub, nil 978 case ECDSA: 979 paramsData := keyData.Algorithm.Parameters.FullBytes 980 namedCurveOID := new(asn1.ObjectIdentifier) 981 rest, err := asn1.Unmarshal(paramsData, namedCurveOID) 982 if err != nil { 983 return nil, errors.New("x509: failed to parse ECDSA parameters as named curve") 984 } 985 if len(rest) != 0 { 986 return nil, errors.New("x509: trailing data after ECDSA parameters") 987 } 988 namedCurve := namedCurveFromOID(*namedCurveOID) 989 if namedCurve == nil { 990 return nil, errors.New("x509: unsupported elliptic curve") 991 } 992 x, y := elliptic.Unmarshal(namedCurve, asn1Data) 993 if x == nil { 994 return nil, errors.New("x509: failed to unmarshal elliptic curve point") 995 } 996 pub := &ecdsa.PublicKey{ 997 Curve: namedCurve, 998 X: x, 999 Y: y, 1000 } 1001 return pub, nil 1002 case Ed25519: 1003 // RFC 8410, Section 3 1004 // > For all of the OIDs, the parameters MUST be absent. 1005 if len(keyData.Algorithm.Parameters.FullBytes) != 0 { 1006 return nil, errors.New("x509: Ed25519 key encoded with illegal parameters") 1007 } 1008 if len(asn1Data) != ed25519.PublicKeySize { 1009 return nil, errors.New("x509: wrong Ed25519 public key size") 1010 } 1011 pub := make([]byte, ed25519.PublicKeySize) 1012 copy(pub, asn1Data) 1013 return ed25519.PublicKey(pub), nil 1014 default: 1015 return nil, nil 1016 } 1017} 1018 1019func forEachSAN(extension []byte, callback func(tag int, data []byte) error) error { 1020 // RFC 5280, 4.2.1.6 1021 1022 // SubjectAltName ::= GeneralNames 1023 // 1024 // GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName 1025 // 1026 // GeneralName ::= CHOICE { 1027 // otherName [0] OtherName, 1028 // rfc822Name [1] IA5String, 1029 // dNSName [2] IA5String, 1030 // x400Address [3] ORAddress, 1031 // directoryName [4] Name, 1032 // ediPartyName [5] EDIPartyName, 1033 // uniformResourceIdentifier [6] IA5String, 1034 // iPAddress [7] OCTET STRING, 1035 // registeredID [8] OBJECT IDENTIFIER } 1036 var seq asn1.RawValue 1037 rest, err := asn1.Unmarshal(extension, &seq) 1038 if err != nil { 1039 return err 1040 } else if len(rest) != 0 { 1041 return errors.New("x509: trailing data after X.509 extension") 1042 } 1043 if !seq.IsCompound || seq.Tag != 16 || seq.Class != 0 { 1044 return asn1.StructuralError{Msg: "bad SAN sequence"} 1045 } 1046 1047 rest = seq.Bytes 1048 for len(rest) > 0 { 1049 var v asn1.RawValue 1050 rest, err = asn1.Unmarshal(rest, &v) 1051 if err != nil { 1052 return err 1053 } 1054 1055 if err := callback(v.Tag, v.Bytes); err != nil { 1056 return err 1057 } 1058 } 1059 1060 return nil 1061} 1062 1063func parseSANExtension(value []byte) (dnsNames, emailAddresses []string, ipAddresses []net.IP, uris []*url.URL, err error) { 1064 err = forEachSAN(value, func(tag int, data []byte) error { 1065 switch tag { 1066 case nameTypeEmail: 1067 email := string(data) 1068 if err := isIA5String(email); err != nil { 1069 return errors.New("x509: SAN rfc822Name is malformed") 1070 } 1071 emailAddresses = append(emailAddresses, email) 1072 case nameTypeDNS: 1073 name := string(data) 1074 if err := isIA5String(name); err != nil { 1075 return errors.New("x509: SAN dNSName is malformed") 1076 } 1077 dnsNames = append(dnsNames, string(name)) 1078 case nameTypeURI: 1079 uriStr := string(data) 1080 if err := isIA5String(uriStr); err != nil { 1081 return errors.New("x509: SAN uniformResourceIdentifier is malformed") 1082 } 1083 uri, err := url.Parse(uriStr) 1084 if err != nil { 1085 return fmt.Errorf("x509: cannot parse URI %q: %s", uriStr, err) 1086 } 1087 if len(uri.Host) > 0 { 1088 if _, ok := domainToReverseLabels(uri.Host); !ok { 1089 return fmt.Errorf("x509: cannot parse URI %q: invalid domain", uriStr) 1090 } 1091 } 1092 uris = append(uris, uri) 1093 case nameTypeIP: 1094 switch len(data) { 1095 case net.IPv4len, net.IPv6len: 1096 ipAddresses = append(ipAddresses, data) 1097 default: 1098 return errors.New("x509: cannot parse IP address of length " + strconv.Itoa(len(data))) 1099 } 1100 } 1101 1102 return nil 1103 }) 1104 1105 return 1106} 1107 1108// isValidIPMask reports whether mask consists of zero or more 1 bits, followed by zero bits. 1109func isValidIPMask(mask []byte) bool { 1110 seenZero := false 1111 1112 for _, b := range mask { 1113 if seenZero { 1114 if b != 0 { 1115 return false 1116 } 1117 1118 continue 1119 } 1120 1121 switch b { 1122 case 0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe: 1123 seenZero = true 1124 case 0xff: 1125 default: 1126 return false 1127 } 1128 } 1129 1130 return true 1131} 1132 1133func parseNameConstraintsExtension(out *Certificate, e pkix.Extension) (unhandled bool, err error) { 1134 // RFC 5280, 4.2.1.10 1135 1136 // NameConstraints ::= SEQUENCE { 1137 // permittedSubtrees [0] GeneralSubtrees OPTIONAL, 1138 // excludedSubtrees [1] GeneralSubtrees OPTIONAL } 1139 // 1140 // GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree 1141 // 1142 // GeneralSubtree ::= SEQUENCE { 1143 // base GeneralName, 1144 // minimum [0] BaseDistance DEFAULT 0, 1145 // maximum [1] BaseDistance OPTIONAL } 1146 // 1147 // BaseDistance ::= INTEGER (0..MAX) 1148 1149 outer := cryptobyte.String(e.Value) 1150 var toplevel, permitted, excluded cryptobyte.String 1151 var havePermitted, haveExcluded bool 1152 if !outer.ReadASN1(&toplevel, cryptobyte_asn1.SEQUENCE) || 1153 !outer.Empty() || 1154 !toplevel.ReadOptionalASN1(&permitted, &havePermitted, cryptobyte_asn1.Tag(0).ContextSpecific().Constructed()) || 1155 !toplevel.ReadOptionalASN1(&excluded, &haveExcluded, cryptobyte_asn1.Tag(1).ContextSpecific().Constructed()) || 1156 !toplevel.Empty() { 1157 return false, errors.New("x509: invalid NameConstraints extension") 1158 } 1159 1160 if !havePermitted && !haveExcluded || len(permitted) == 0 && len(excluded) == 0 { 1161 // From RFC 5280, Section 4.2.1.10: 1162 // “either the permittedSubtrees field 1163 // or the excludedSubtrees MUST be 1164 // present” 1165 return false, errors.New("x509: empty name constraints extension") 1166 } 1167 1168 getValues := func(subtrees cryptobyte.String) (dnsNames []string, ips []*net.IPNet, emails, uriDomains []string, err error) { 1169 for !subtrees.Empty() { 1170 var seq, value cryptobyte.String 1171 var tag cryptobyte_asn1.Tag 1172 if !subtrees.ReadASN1(&seq, cryptobyte_asn1.SEQUENCE) || 1173 !seq.ReadAnyASN1(&value, &tag) { 1174 return nil, nil, nil, nil, fmt.Errorf("x509: invalid NameConstraints extension") 1175 } 1176 1177 var ( 1178 dnsTag = cryptobyte_asn1.Tag(2).ContextSpecific() 1179 emailTag = cryptobyte_asn1.Tag(1).ContextSpecific() 1180 ipTag = cryptobyte_asn1.Tag(7).ContextSpecific() 1181 uriTag = cryptobyte_asn1.Tag(6).ContextSpecific() 1182 ) 1183 1184 switch tag { 1185 case dnsTag: 1186 domain := string(value) 1187 if err := isIA5String(domain); err != nil { 1188 return nil, nil, nil, nil, errors.New("x509: invalid constraint value: " + err.Error()) 1189 } 1190 1191 trimmedDomain := domain 1192 if len(trimmedDomain) > 0 && trimmedDomain[0] == '.' { 1193 // constraints can have a leading 1194 // period to exclude the domain 1195 // itself, but that's not valid in a 1196 // normal domain name. 1197 trimmedDomain = trimmedDomain[1:] 1198 } 1199 if _, ok := domainToReverseLabels(trimmedDomain); !ok { 1200 return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse dnsName constraint %q", domain) 1201 } 1202 dnsNames = append(dnsNames, domain) 1203 1204 case ipTag: 1205 l := len(value) 1206 var ip, mask []byte 1207 1208 switch l { 1209 case 8: 1210 ip = value[:4] 1211 mask = value[4:] 1212 1213 case 32: 1214 ip = value[:16] 1215 mask = value[16:] 1216 1217 default: 1218 return nil, nil, nil, nil, fmt.Errorf("x509: IP constraint contained value of length %d", l) 1219 } 1220 1221 if !isValidIPMask(mask) { 1222 return nil, nil, nil, nil, fmt.Errorf("x509: IP constraint contained invalid mask %x", mask) 1223 } 1224 1225 ips = append(ips, &net.IPNet{IP: net.IP(ip), Mask: net.IPMask(mask)}) 1226 1227 case emailTag: 1228 constraint := string(value) 1229 if err := isIA5String(constraint); err != nil { 1230 return nil, nil, nil, nil, errors.New("x509: invalid constraint value: " + err.Error()) 1231 } 1232 1233 // If the constraint contains an @ then 1234 // it specifies an exact mailbox name. 1235 if strings.Contains(constraint, "@") { 1236 if _, ok := parseRFC2821Mailbox(constraint); !ok { 1237 return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse rfc822Name constraint %q", constraint) 1238 } 1239 } else { 1240 // Otherwise it's a domain name. 1241 domain := constraint 1242 if len(domain) > 0 && domain[0] == '.' { 1243 domain = domain[1:] 1244 } 1245 if _, ok := domainToReverseLabels(domain); !ok { 1246 return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse rfc822Name constraint %q", constraint) 1247 } 1248 } 1249 emails = append(emails, constraint) 1250 1251 case uriTag: 1252 domain := string(value) 1253 if err := isIA5String(domain); err != nil { 1254 return nil, nil, nil, nil, errors.New("x509: invalid constraint value: " + err.Error()) 1255 } 1256 1257 if net.ParseIP(domain) != nil { 1258 return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse URI constraint %q: cannot be IP address", domain) 1259 } 1260 1261 trimmedDomain := domain 1262 if len(trimmedDomain) > 0 && trimmedDomain[0] == '.' { 1263 // constraints can have a leading 1264 // period to exclude the domain itself, 1265 // but that's not valid in a normal 1266 // domain name. 1267 trimmedDomain = trimmedDomain[1:] 1268 } 1269 if _, ok := domainToReverseLabels(trimmedDomain); !ok { 1270 return nil, nil, nil, nil, fmt.Errorf("x509: failed to parse URI constraint %q", domain) 1271 } 1272 uriDomains = append(uriDomains, domain) 1273 1274 default: 1275 unhandled = true 1276 } 1277 } 1278 1279 return dnsNames, ips, emails, uriDomains, nil 1280 } 1281 1282 if out.PermittedDNSDomains, out.PermittedIPRanges, out.PermittedEmailAddresses, out.PermittedURIDomains, err = getValues(permitted); err != nil { 1283 return false, err 1284 } 1285 if out.ExcludedDNSDomains, out.ExcludedIPRanges, out.ExcludedEmailAddresses, out.ExcludedURIDomains, err = getValues(excluded); err != nil { 1286 return false, err 1287 } 1288 out.PermittedDNSDomainsCritical = e.Critical 1289 1290 return unhandled, nil 1291} 1292 1293func parseCertificate(in *certificate) (*Certificate, error) { 1294 out := new(Certificate) 1295 out.Raw = in.Raw 1296 out.RawTBSCertificate = in.TBSCertificate.Raw 1297 out.RawSubjectPublicKeyInfo = in.TBSCertificate.PublicKey.Raw 1298 out.RawSubject = in.TBSCertificate.Subject.FullBytes 1299 out.RawIssuer = in.TBSCertificate.Issuer.FullBytes 1300 1301 out.Signature = in.SignatureValue.RightAlign() 1302 out.SignatureAlgorithm = 1303 getSignatureAlgorithmFromAI(in.TBSCertificate.SignatureAlgorithm) 1304 1305 out.PublicKeyAlgorithm = 1306 getPublicKeyAlgorithmFromOID(in.TBSCertificate.PublicKey.Algorithm.Algorithm) 1307 var err error 1308 out.PublicKey, err = parsePublicKey(out.PublicKeyAlgorithm, &in.TBSCertificate.PublicKey) 1309 if err != nil { 1310 return nil, err 1311 } 1312 1313 out.Version = in.TBSCertificate.Version + 1 1314 out.SerialNumber = in.TBSCertificate.SerialNumber 1315 1316 var issuer, subject pkix.RDNSequence 1317 if rest, err := asn1.Unmarshal(in.TBSCertificate.Subject.FullBytes, &subject); err != nil { 1318 return nil, err 1319 } else if len(rest) != 0 { 1320 return nil, errors.New("x509: trailing data after X.509 subject") 1321 } 1322 if rest, err := asn1.Unmarshal(in.TBSCertificate.Issuer.FullBytes, &issuer); err != nil { 1323 return nil, err 1324 } else if len(rest) != 0 { 1325 return nil, errors.New("x509: trailing data after X.509 issuer") 1326 } 1327 1328 out.Issuer.FillFromRDNSequence(&issuer) 1329 out.Subject.FillFromRDNSequence(&subject) 1330 1331 out.NotBefore = in.TBSCertificate.Validity.NotBefore 1332 out.NotAfter = in.TBSCertificate.Validity.NotAfter 1333 1334 for _, e := range in.TBSCertificate.Extensions { 1335 out.Extensions = append(out.Extensions, e) 1336 unhandled := false 1337 1338 if len(e.Id) == 4 && e.Id[0] == 2 && e.Id[1] == 5 && e.Id[2] == 29 { 1339 switch e.Id[3] { 1340 case 15: 1341 out.KeyUsage, err = parseKeyUsageExtension(e.Value) 1342 if err != nil { 1343 return nil, err 1344 } 1345 case 19: 1346 out.IsCA, out.MaxPathLen, err = parseBasicConstraintsExtension(e.Value) 1347 if err != nil { 1348 return nil, err 1349 } 1350 out.BasicConstraintsValid = true 1351 out.MaxPathLenZero = out.MaxPathLen == 0 1352 case 17: 1353 out.DNSNames, out.EmailAddresses, out.IPAddresses, out.URIs, err = parseSANExtension(e.Value) 1354 if err != nil { 1355 return nil, err 1356 } 1357 1358 if len(out.DNSNames) == 0 && len(out.EmailAddresses) == 0 && len(out.IPAddresses) == 0 && len(out.URIs) == 0 { 1359 // If we didn't parse anything then we do the critical check, below. 1360 unhandled = true 1361 } 1362 1363 case 30: 1364 unhandled, err = parseNameConstraintsExtension(out, e) 1365 if err != nil { 1366 return nil, err 1367 } 1368 1369 case 31: 1370 // RFC 5280, 4.2.1.13 1371 1372 // CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint 1373 // 1374 // DistributionPoint ::= SEQUENCE { 1375 // distributionPoint [0] DistributionPointName OPTIONAL, 1376 // reasons [1] ReasonFlags OPTIONAL, 1377 // cRLIssuer [2] GeneralNames OPTIONAL } 1378 // 1379 // DistributionPointName ::= CHOICE { 1380 // fullName [0] GeneralNames, 1381 // nameRelativeToCRLIssuer [1] RelativeDistinguishedName } 1382 1383 var cdp []distributionPoint 1384 if rest, err := asn1.Unmarshal(e.Value, &cdp); err != nil { 1385 return nil, err 1386 } else if len(rest) != 0 { 1387 return nil, errors.New("x509: trailing data after X.509 CRL distribution point") 1388 } 1389 1390 for _, dp := range cdp { 1391 // Per RFC 5280, 4.2.1.13, one of distributionPoint or cRLIssuer may be empty. 1392 if len(dp.DistributionPoint.FullName) == 0 { 1393 continue 1394 } 1395 1396 for _, fullName := range dp.DistributionPoint.FullName { 1397 if fullName.Tag == 6 { 1398 out.CRLDistributionPoints = append(out.CRLDistributionPoints, string(fullName.Bytes)) 1399 } 1400 } 1401 } 1402 1403 case 35: 1404 // RFC 5280, 4.2.1.1 1405 var a authKeyId 1406 if rest, err := asn1.Unmarshal(e.Value, &a); err != nil { 1407 return nil, err 1408 } else if len(rest) != 0 { 1409 return nil, errors.New("x509: trailing data after X.509 authority key-id") 1410 } 1411 out.AuthorityKeyId = a.Id 1412 1413 case 37: 1414 out.ExtKeyUsage, out.UnknownExtKeyUsage, err = parseExtKeyUsageExtension(e.Value) 1415 if err != nil { 1416 return nil, err 1417 } 1418 case 14: 1419 out.SubjectKeyId, err = parseSubjectKeyIdExtension(e.Value) 1420 if err != nil { 1421 return nil, err 1422 } 1423 case 32: 1424 out.PolicyIdentifiers, err = parseCertificatePoliciesExtension(e.Value) 1425 if err != nil { 1426 return nil, err 1427 } 1428 default: 1429 // Unknown extensions are recorded if critical. 1430 unhandled = true 1431 } 1432 } else if e.Id.Equal(oidExtensionAuthorityInfoAccess) { 1433 // RFC 5280 4.2.2.1: Authority Information Access 1434 var aia []authorityInfoAccess 1435 if rest, err := asn1.Unmarshal(e.Value, &aia); err != nil { 1436 return nil, err 1437 } else if len(rest) != 0 { 1438 return nil, errors.New("x509: trailing data after X.509 authority information") 1439 } 1440 1441 for _, v := range aia { 1442 // GeneralName: uniformResourceIdentifier [6] IA5String 1443 if v.Location.Tag != 6 { 1444 continue 1445 } 1446 if v.Method.Equal(oidAuthorityInfoAccessOcsp) { 1447 out.OCSPServer = append(out.OCSPServer, string(v.Location.Bytes)) 1448 } else if v.Method.Equal(oidAuthorityInfoAccessIssuers) { 1449 out.IssuingCertificateURL = append(out.IssuingCertificateURL, string(v.Location.Bytes)) 1450 } 1451 } 1452 } else { 1453 // Unknown extensions are recorded if critical. 1454 unhandled = true 1455 } 1456 1457 if e.Critical && unhandled { 1458 out.UnhandledCriticalExtensions = append(out.UnhandledCriticalExtensions, e.Id) 1459 } 1460 } 1461 1462 return out, nil 1463} 1464 1465// parseKeyUsageExtension parses id-ce-keyUsage (2.5.29.15) from RFC 5280 1466// Section 4.2.1.3 1467func parseKeyUsageExtension(ext []byte) (KeyUsage, error) { 1468 var usageBits asn1.BitString 1469 if rest, err := asn1.Unmarshal(ext, &usageBits); err != nil { 1470 return 0, err 1471 } else if len(rest) != 0 { 1472 return 0, errors.New("x509: trailing data after X.509 KeyUsage") 1473 } 1474 1475 var usage int 1476 for i := 0; i < 9; i++ { 1477 if usageBits.At(i) != 0 { 1478 usage |= 1 << uint(i) 1479 } 1480 } 1481 return KeyUsage(usage), nil 1482} 1483 1484// parseBasicConstraintsExtension parses id-ce-basicConstraints (2.5.29.19) 1485// from RFC 5280 Section 4.2.1.9 1486func parseBasicConstraintsExtension(ext []byte) (isCA bool, maxPathLen int, err error) { 1487 var constraints basicConstraints 1488 if rest, err := asn1.Unmarshal(ext, &constraints); err != nil { 1489 return false, 0, err 1490 } else if len(rest) != 0 { 1491 return false, 0, errors.New("x509: trailing data after X.509 BasicConstraints") 1492 } 1493 1494 // TODO: map out.MaxPathLen to 0 if it has the -1 default value? (Issue 19285) 1495 return constraints.IsCA, constraints.MaxPathLen, nil 1496} 1497 1498// parseExtKeyUsageExtension parses id-ce-extKeyUsage (2.5.29.37) from 1499// RFC 5280 Section 4.2.1.12 1500func parseExtKeyUsageExtension(ext []byte) ([]ExtKeyUsage, []asn1.ObjectIdentifier, error) { 1501 var keyUsage []asn1.ObjectIdentifier 1502 if rest, err := asn1.Unmarshal(ext, &keyUsage); err != nil { 1503 return nil, nil, err 1504 } else if len(rest) != 0 { 1505 return nil, nil, errors.New("x509: trailing data after X.509 ExtendedKeyUsage") 1506 } 1507 1508 var extKeyUsages []ExtKeyUsage 1509 var unknownUsages []asn1.ObjectIdentifier 1510 for _, u := range keyUsage { 1511 if extKeyUsage, ok := extKeyUsageFromOID(u); ok { 1512 extKeyUsages = append(extKeyUsages, extKeyUsage) 1513 } else { 1514 unknownUsages = append(unknownUsages, u) 1515 } 1516 } 1517 return extKeyUsages, unknownUsages, nil 1518} 1519 1520// parseSubjectKeyIdExtension parses id-ce-subjectKeyIdentifier (2.5.29.14) 1521// from RFC 5280 Section 4.2.1.2 1522func parseSubjectKeyIdExtension(ext []byte) ([]byte, error) { 1523 var keyid []byte 1524 if rest, err := asn1.Unmarshal(ext, &keyid); err != nil { 1525 return nil, err 1526 } else if len(rest) != 0 { 1527 return nil, errors.New("x509: trailing data after X.509 key-id") 1528 } 1529 return keyid, nil 1530} 1531 1532func parseCertificatePoliciesExtension(ext []byte) ([]asn1.ObjectIdentifier, error) { 1533 var policies []policyInformation 1534 if rest, err := asn1.Unmarshal(ext, &policies); err != nil { 1535 return nil, err 1536 } else if len(rest) != 0 { 1537 return nil, errors.New("x509: trailing data after X.509 certificate policies") 1538 } 1539 oids := make([]asn1.ObjectIdentifier, len(policies)) 1540 for i, policy := range policies { 1541 oids[i] = policy.Policy 1542 } 1543 return oids, nil 1544} 1545 1546// ParseCertificate parses a single certificate from the given ASN.1 DER data. 1547func ParseCertificate(asn1Data []byte) (*Certificate, error) { 1548 var cert certificate 1549 rest, err := asn1.Unmarshal(asn1Data, &cert) 1550 if err != nil { 1551 return nil, err 1552 } 1553 if len(rest) > 0 { 1554 return nil, asn1.SyntaxError{Msg: "trailing data"} 1555 } 1556 1557 return parseCertificate(&cert) 1558} 1559 1560// ParseCertificates parses one or more certificates from the given ASN.1 DER 1561// data. The certificates must be concatenated with no intermediate padding. 1562func ParseCertificates(asn1Data []byte) ([]*Certificate, error) { 1563 var v []*certificate 1564 1565 for len(asn1Data) > 0 { 1566 cert := new(certificate) 1567 var err error 1568 asn1Data, err = asn1.Unmarshal(asn1Data, cert) 1569 if err != nil { 1570 return nil, err 1571 } 1572 v = append(v, cert) 1573 } 1574 1575 ret := make([]*Certificate, len(v)) 1576 for i, ci := range v { 1577 cert, err := parseCertificate(ci) 1578 if err != nil { 1579 return nil, err 1580 } 1581 ret[i] = cert 1582 } 1583 1584 return ret, nil 1585} 1586 1587func reverseBitsInAByte(in byte) byte { 1588 b1 := in>>4 | in<<4 1589 b2 := b1>>2&0x33 | b1<<2&0xcc 1590 b3 := b2>>1&0x55 | b2<<1&0xaa 1591 return b3 1592} 1593 1594// asn1BitLength returns the bit-length of bitString by considering the 1595// most-significant bit in a byte to be the "first" bit. This convention 1596// matches ASN.1, but differs from almost everything else. 1597func asn1BitLength(bitString []byte) int { 1598 bitLen := len(bitString) * 8 1599 1600 for i := range bitString { 1601 b := bitString[len(bitString)-i-1] 1602 1603 for bit := uint(0); bit < 8; bit++ { 1604 if (b>>bit)&1 == 1 { 1605 return bitLen 1606 } 1607 bitLen-- 1608 } 1609 } 1610 1611 return 0 1612} 1613 1614var ( 1615 oidExtensionSubjectKeyId = []int{2, 5, 29, 14} 1616 oidExtensionKeyUsage = []int{2, 5, 29, 15} 1617 oidExtensionExtendedKeyUsage = []int{2, 5, 29, 37} 1618 oidExtensionAuthorityKeyId = []int{2, 5, 29, 35} 1619 oidExtensionBasicConstraints = []int{2, 5, 29, 19} 1620 oidExtensionSubjectAltName = []int{2, 5, 29, 17} 1621 oidExtensionCertificatePolicies = []int{2, 5, 29, 32} 1622 oidExtensionNameConstraints = []int{2, 5, 29, 30} 1623 oidExtensionCRLDistributionPoints = []int{2, 5, 29, 31} 1624 oidExtensionAuthorityInfoAccess = []int{1, 3, 6, 1, 5, 5, 7, 1, 1} 1625 oidExtensionCRLNumber = []int{2, 5, 29, 20} 1626) 1627 1628var ( 1629 oidAuthorityInfoAccessOcsp = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 48, 1} 1630 oidAuthorityInfoAccessIssuers = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 48, 2} 1631) 1632 1633// oidNotInExtensions reports whether an extension with the given oid exists in 1634// extensions. 1635func oidInExtensions(oid asn1.ObjectIdentifier, extensions []pkix.Extension) bool { 1636 for _, e := range extensions { 1637 if e.Id.Equal(oid) { 1638 return true 1639 } 1640 } 1641 return false 1642} 1643 1644// marshalSANs marshals a list of addresses into a the contents of an X.509 1645// SubjectAlternativeName extension. 1646func marshalSANs(dnsNames, emailAddresses []string, ipAddresses []net.IP, uris []*url.URL) (derBytes []byte, err error) { 1647 var rawValues []asn1.RawValue 1648 for _, name := range dnsNames { 1649 if err := isIA5String(name); err != nil { 1650 return nil, err 1651 } 1652 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeDNS, Class: 2, Bytes: []byte(name)}) 1653 } 1654 for _, email := range emailAddresses { 1655 if err := isIA5String(email); err != nil { 1656 return nil, err 1657 } 1658 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeEmail, Class: 2, Bytes: []byte(email)}) 1659 } 1660 for _, rawIP := range ipAddresses { 1661 // If possible, we always want to encode IPv4 addresses in 4 bytes. 1662 ip := rawIP.To4() 1663 if ip == nil { 1664 ip = rawIP 1665 } 1666 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeIP, Class: 2, Bytes: ip}) 1667 } 1668 for _, uri := range uris { 1669 uriStr := uri.String() 1670 if err := isIA5String(uriStr); err != nil { 1671 return nil, err 1672 } 1673 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeURI, Class: 2, Bytes: []byte(uriStr)}) 1674 } 1675 return asn1.Marshal(rawValues) 1676} 1677 1678func isIA5String(s string) error { 1679 for _, r := range s { 1680 // Per RFC5280 "IA5String is limited to the set of ASCII characters" 1681 if r > unicode.MaxASCII { 1682 return fmt.Errorf("x509: %q cannot be encoded as an IA5String", s) 1683 } 1684 } 1685 1686 return nil 1687} 1688 1689func buildCertExtensions(template *Certificate, subjectIsEmpty bool, authorityKeyId []byte, subjectKeyId []byte) (ret []pkix.Extension, err error) { 1690 ret = make([]pkix.Extension, 10 /* maximum number of elements. */) 1691 n := 0 1692 1693 if template.KeyUsage != 0 && 1694 !oidInExtensions(oidExtensionKeyUsage, template.ExtraExtensions) { 1695 ret[n], err = marshalKeyUsage(template.KeyUsage) 1696 if err != nil { 1697 return nil, err 1698 } 1699 n++ 1700 } 1701 1702 if (len(template.ExtKeyUsage) > 0 || len(template.UnknownExtKeyUsage) > 0) && 1703 !oidInExtensions(oidExtensionExtendedKeyUsage, template.ExtraExtensions) { 1704 ret[n], err = marshalExtKeyUsage(template.ExtKeyUsage, template.UnknownExtKeyUsage) 1705 if err != nil { 1706 return nil, err 1707 } 1708 n++ 1709 } 1710 1711 if template.BasicConstraintsValid && !oidInExtensions(oidExtensionBasicConstraints, template.ExtraExtensions) { 1712 ret[n], err = marshalBasicConstraints(template.IsCA, template.MaxPathLen, template.MaxPathLenZero) 1713 if err != nil { 1714 return nil, err 1715 } 1716 n++ 1717 } 1718 1719 if len(subjectKeyId) > 0 && !oidInExtensions(oidExtensionSubjectKeyId, template.ExtraExtensions) { 1720 ret[n].Id = oidExtensionSubjectKeyId 1721 ret[n].Value, err = asn1.Marshal(subjectKeyId) 1722 if err != nil { 1723 return 1724 } 1725 n++ 1726 } 1727 1728 if len(authorityKeyId) > 0 && !oidInExtensions(oidExtensionAuthorityKeyId, template.ExtraExtensions) { 1729 ret[n].Id = oidExtensionAuthorityKeyId 1730 ret[n].Value, err = asn1.Marshal(authKeyId{authorityKeyId}) 1731 if err != nil { 1732 return 1733 } 1734 n++ 1735 } 1736 1737 if (len(template.OCSPServer) > 0 || len(template.IssuingCertificateURL) > 0) && 1738 !oidInExtensions(oidExtensionAuthorityInfoAccess, template.ExtraExtensions) { 1739 ret[n].Id = oidExtensionAuthorityInfoAccess 1740 var aiaValues []authorityInfoAccess 1741 for _, name := range template.OCSPServer { 1742 aiaValues = append(aiaValues, authorityInfoAccess{ 1743 Method: oidAuthorityInfoAccessOcsp, 1744 Location: asn1.RawValue{Tag: 6, Class: 2, Bytes: []byte(name)}, 1745 }) 1746 } 1747 for _, name := range template.IssuingCertificateURL { 1748 aiaValues = append(aiaValues, authorityInfoAccess{ 1749 Method: oidAuthorityInfoAccessIssuers, 1750 Location: asn1.RawValue{Tag: 6, Class: 2, Bytes: []byte(name)}, 1751 }) 1752 } 1753 ret[n].Value, err = asn1.Marshal(aiaValues) 1754 if err != nil { 1755 return 1756 } 1757 n++ 1758 } 1759 1760 if (len(template.DNSNames) > 0 || len(template.EmailAddresses) > 0 || len(template.IPAddresses) > 0 || len(template.URIs) > 0) && 1761 !oidInExtensions(oidExtensionSubjectAltName, template.ExtraExtensions) { 1762 ret[n].Id = oidExtensionSubjectAltName 1763 // From RFC 5280, Section 4.2.1.6: 1764 // “If the subject field contains an empty sequence ... then 1765 // subjectAltName extension ... is marked as critical” 1766 ret[n].Critical = subjectIsEmpty 1767 ret[n].Value, err = marshalSANs(template.DNSNames, template.EmailAddresses, template.IPAddresses, template.URIs) 1768 if err != nil { 1769 return 1770 } 1771 n++ 1772 } 1773 1774 if len(template.PolicyIdentifiers) > 0 && 1775 !oidInExtensions(oidExtensionCertificatePolicies, template.ExtraExtensions) { 1776 ret[n], err = marshalCertificatePolicies(template.PolicyIdentifiers) 1777 if err != nil { 1778 return nil, err 1779 } 1780 n++ 1781 } 1782 1783 if (len(template.PermittedDNSDomains) > 0 || len(template.ExcludedDNSDomains) > 0 || 1784 len(template.PermittedIPRanges) > 0 || len(template.ExcludedIPRanges) > 0 || 1785 len(template.PermittedEmailAddresses) > 0 || len(template.ExcludedEmailAddresses) > 0 || 1786 len(template.PermittedURIDomains) > 0 || len(template.ExcludedURIDomains) > 0) && 1787 !oidInExtensions(oidExtensionNameConstraints, template.ExtraExtensions) { 1788 ret[n].Id = oidExtensionNameConstraints 1789 ret[n].Critical = template.PermittedDNSDomainsCritical 1790 1791 ipAndMask := func(ipNet *net.IPNet) []byte { 1792 maskedIP := ipNet.IP.Mask(ipNet.Mask) 1793 ipAndMask := make([]byte, 0, len(maskedIP)+len(ipNet.Mask)) 1794 ipAndMask = append(ipAndMask, maskedIP...) 1795 ipAndMask = append(ipAndMask, ipNet.Mask...) 1796 return ipAndMask 1797 } 1798 1799 serialiseConstraints := func(dns []string, ips []*net.IPNet, emails []string, uriDomains []string) (der []byte, err error) { 1800 var b cryptobyte.Builder 1801 1802 for _, name := range dns { 1803 if err = isIA5String(name); err != nil { 1804 return nil, err 1805 } 1806 1807 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) { 1808 b.AddASN1(cryptobyte_asn1.Tag(2).ContextSpecific(), func(b *cryptobyte.Builder) { 1809 b.AddBytes([]byte(name)) 1810 }) 1811 }) 1812 } 1813 1814 for _, ipNet := range ips { 1815 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) { 1816 b.AddASN1(cryptobyte_asn1.Tag(7).ContextSpecific(), func(b *cryptobyte.Builder) { 1817 b.AddBytes(ipAndMask(ipNet)) 1818 }) 1819 }) 1820 } 1821 1822 for _, email := range emails { 1823 if err = isIA5String(email); err != nil { 1824 return nil, err 1825 } 1826 1827 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) { 1828 b.AddASN1(cryptobyte_asn1.Tag(1).ContextSpecific(), func(b *cryptobyte.Builder) { 1829 b.AddBytes([]byte(email)) 1830 }) 1831 }) 1832 } 1833 1834 for _, uriDomain := range uriDomains { 1835 if err = isIA5String(uriDomain); err != nil { 1836 return nil, err 1837 } 1838 1839 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) { 1840 b.AddASN1(cryptobyte_asn1.Tag(6).ContextSpecific(), func(b *cryptobyte.Builder) { 1841 b.AddBytes([]byte(uriDomain)) 1842 }) 1843 }) 1844 } 1845 1846 return b.Bytes() 1847 } 1848 1849 permitted, err := serialiseConstraints(template.PermittedDNSDomains, template.PermittedIPRanges, template.PermittedEmailAddresses, template.PermittedURIDomains) 1850 if err != nil { 1851 return nil, err 1852 } 1853 1854 excluded, err := serialiseConstraints(template.ExcludedDNSDomains, template.ExcludedIPRanges, template.ExcludedEmailAddresses, template.ExcludedURIDomains) 1855 if err != nil { 1856 return nil, err 1857 } 1858 1859 var b cryptobyte.Builder 1860 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) { 1861 if len(permitted) > 0 { 1862 b.AddASN1(cryptobyte_asn1.Tag(0).ContextSpecific().Constructed(), func(b *cryptobyte.Builder) { 1863 b.AddBytes(permitted) 1864 }) 1865 } 1866 1867 if len(excluded) > 0 { 1868 b.AddASN1(cryptobyte_asn1.Tag(1).ContextSpecific().Constructed(), func(b *cryptobyte.Builder) { 1869 b.AddBytes(excluded) 1870 }) 1871 } 1872 }) 1873 1874 ret[n].Value, err = b.Bytes() 1875 if err != nil { 1876 return nil, err 1877 } 1878 n++ 1879 } 1880 1881 if len(template.CRLDistributionPoints) > 0 && 1882 !oidInExtensions(oidExtensionCRLDistributionPoints, template.ExtraExtensions) { 1883 ret[n].Id = oidExtensionCRLDistributionPoints 1884 1885 var crlDp []distributionPoint 1886 for _, name := range template.CRLDistributionPoints { 1887 dp := distributionPoint{ 1888 DistributionPoint: distributionPointName{ 1889 FullName: []asn1.RawValue{ 1890 {Tag: 6, Class: 2, Bytes: []byte(name)}, 1891 }, 1892 }, 1893 } 1894 crlDp = append(crlDp, dp) 1895 } 1896 1897 ret[n].Value, err = asn1.Marshal(crlDp) 1898 if err != nil { 1899 return 1900 } 1901 n++ 1902 } 1903 1904 // Adding another extension here? Remember to update the maximum number 1905 // of elements in the make() at the top of the function and the list of 1906 // template fields used in CreateCertificate documentation. 1907 1908 return append(ret[:n], template.ExtraExtensions...), nil 1909} 1910 1911func marshalKeyUsage(ku KeyUsage) (pkix.Extension, error) { 1912 ext := pkix.Extension{Id: oidExtensionKeyUsage, Critical: true} 1913 1914 var a [2]byte 1915 a[0] = reverseBitsInAByte(byte(ku)) 1916 a[1] = reverseBitsInAByte(byte(ku >> 8)) 1917 1918 l := 1 1919 if a[1] != 0 { 1920 l = 2 1921 } 1922 1923 bitString := a[:l] 1924 var err error 1925 ext.Value, err = asn1.Marshal(asn1.BitString{Bytes: bitString, BitLength: asn1BitLength(bitString)}) 1926 if err != nil { 1927 return ext, err 1928 } 1929 return ext, nil 1930} 1931 1932func marshalExtKeyUsage(extUsages []ExtKeyUsage, unknownUsages []asn1.ObjectIdentifier) (pkix.Extension, error) { 1933 ext := pkix.Extension{Id: oidExtensionExtendedKeyUsage} 1934 1935 oids := make([]asn1.ObjectIdentifier, len(extUsages)+len(unknownUsages)) 1936 for i, u := range extUsages { 1937 if oid, ok := oidFromExtKeyUsage(u); ok { 1938 oids[i] = oid 1939 } else { 1940 return ext, errors.New("x509: unknown extended key usage") 1941 } 1942 } 1943 1944 copy(oids[len(extUsages):], unknownUsages) 1945 1946 var err error 1947 ext.Value, err = asn1.Marshal(oids) 1948 if err != nil { 1949 return ext, err 1950 } 1951 return ext, nil 1952} 1953 1954func marshalBasicConstraints(isCA bool, maxPathLen int, maxPathLenZero bool) (pkix.Extension, error) { 1955 ext := pkix.Extension{Id: oidExtensionBasicConstraints, Critical: true} 1956 // Leaving MaxPathLen as zero indicates that no maximum path 1957 // length is desired, unless MaxPathLenZero is set. A value of 1958 // -1 causes encoding/asn1 to omit the value as desired. 1959 if maxPathLen == 0 && !maxPathLenZero { 1960 maxPathLen = -1 1961 } 1962 var err error 1963 ext.Value, err = asn1.Marshal(basicConstraints{isCA, maxPathLen}) 1964 if err != nil { 1965 return ext, nil 1966 } 1967 return ext, nil 1968} 1969 1970func marshalCertificatePolicies(policyIdentifiers []asn1.ObjectIdentifier) (pkix.Extension, error) { 1971 ext := pkix.Extension{Id: oidExtensionCertificatePolicies} 1972 policies := make([]policyInformation, len(policyIdentifiers)) 1973 for i, policy := range policyIdentifiers { 1974 policies[i].Policy = policy 1975 } 1976 var err error 1977 ext.Value, err = asn1.Marshal(policies) 1978 if err != nil { 1979 return ext, err 1980 } 1981 return ext, nil 1982} 1983 1984func buildCSRExtensions(template *CertificateRequest) ([]pkix.Extension, error) { 1985 var ret []pkix.Extension 1986 1987 if (len(template.DNSNames) > 0 || len(template.EmailAddresses) > 0 || len(template.IPAddresses) > 0 || len(template.URIs) > 0) && 1988 !oidInExtensions(oidExtensionSubjectAltName, template.ExtraExtensions) { 1989 sanBytes, err := marshalSANs(template.DNSNames, template.EmailAddresses, template.IPAddresses, template.URIs) 1990 if err != nil { 1991 return nil, err 1992 } 1993 1994 ret = append(ret, pkix.Extension{ 1995 Id: oidExtensionSubjectAltName, 1996 Value: sanBytes, 1997 }) 1998 } 1999 2000 return append(ret, template.ExtraExtensions...), nil 2001} 2002 2003func subjectBytes(cert *Certificate) ([]byte, error) { 2004 if len(cert.RawSubject) > 0 { 2005 return cert.RawSubject, nil 2006 } 2007 2008 return asn1.Marshal(cert.Subject.ToRDNSequence()) 2009} 2010 2011// signingParamsForPublicKey returns the parameters to use for signing with 2012// priv. If requestedSigAlgo is not zero then it overrides the default 2013// signature algorithm. 2014func signingParamsForPublicKey(pub interface{}, requestedSigAlgo SignatureAlgorithm) (hashFunc crypto.Hash, sigAlgo pkix.AlgorithmIdentifier, err error) { 2015 var pubType PublicKeyAlgorithm 2016 2017 switch pub := pub.(type) { 2018 case *rsa.PublicKey: 2019 pubType = RSA 2020 hashFunc = crypto.SHA256 2021 sigAlgo.Algorithm = oidSignatureSHA256WithRSA 2022 sigAlgo.Parameters = asn1.NullRawValue 2023 2024 case *ecdsa.PublicKey: 2025 pubType = ECDSA 2026 2027 switch pub.Curve { 2028 case elliptic.P224(), elliptic.P256(): 2029 hashFunc = crypto.SHA256 2030 sigAlgo.Algorithm = oidSignatureECDSAWithSHA256 2031 case elliptic.P384(): 2032 hashFunc = crypto.SHA384 2033 sigAlgo.Algorithm = oidSignatureECDSAWithSHA384 2034 case elliptic.P521(): 2035 hashFunc = crypto.SHA512 2036 sigAlgo.Algorithm = oidSignatureECDSAWithSHA512 2037 default: 2038 err = errors.New("x509: unknown elliptic curve") 2039 } 2040 2041 case ed25519.PublicKey: 2042 pubType = Ed25519 2043 sigAlgo.Algorithm = oidSignatureEd25519 2044 2045 default: 2046 err = errors.New("x509: only RSA, ECDSA and Ed25519 keys supported") 2047 } 2048 2049 if err != nil { 2050 return 2051 } 2052 2053 if requestedSigAlgo == 0 { 2054 return 2055 } 2056 2057 found := false 2058 for _, details := range signatureAlgorithmDetails { 2059 if details.algo == requestedSigAlgo { 2060 if details.pubKeyAlgo != pubType { 2061 err = errors.New("x509: requested SignatureAlgorithm does not match private key type") 2062 return 2063 } 2064 sigAlgo.Algorithm, hashFunc = details.oid, details.hash 2065 if hashFunc == 0 && pubType != Ed25519 { 2066 err = errors.New("x509: cannot sign with hash function requested") 2067 return 2068 } 2069 if requestedSigAlgo.isRSAPSS() { 2070 sigAlgo.Parameters = hashToPSSParameters[hashFunc] 2071 } 2072 found = true 2073 break 2074 } 2075 } 2076 2077 if !found { 2078 err = errors.New("x509: unknown SignatureAlgorithm") 2079 } 2080 2081 return 2082} 2083 2084// emptyASN1Subject is the ASN.1 DER encoding of an empty Subject, which is 2085// just an empty SEQUENCE. 2086var emptyASN1Subject = []byte{0x30, 0} 2087 2088// CreateCertificate creates a new X.509v3 certificate based on a template. 2089// The following members of template are used: 2090// 2091// - AuthorityKeyId 2092// - BasicConstraintsValid 2093// - CRLDistributionPoints 2094// - DNSNames 2095// - EmailAddresses 2096// - ExcludedDNSDomains 2097// - ExcludedEmailAddresses 2098// - ExcludedIPRanges 2099// - ExcludedURIDomains 2100// - ExtKeyUsage 2101// - ExtraExtensions 2102// - IPAddresses 2103// - IsCA 2104// - IssuingCertificateURL 2105// - KeyUsage 2106// - MaxPathLen 2107// - MaxPathLenZero 2108// - NotAfter 2109// - NotBefore 2110// - OCSPServer 2111// - PermittedDNSDomains 2112// - PermittedDNSDomainsCritical 2113// - PermittedEmailAddresses 2114// - PermittedIPRanges 2115// - PermittedURIDomains 2116// - PolicyIdentifiers 2117// - SerialNumber 2118// - SignatureAlgorithm 2119// - Subject 2120// - SubjectKeyId 2121// - URIs 2122// - UnknownExtKeyUsage 2123// 2124// The certificate is signed by parent. If parent is equal to template then the 2125// certificate is self-signed. The parameter pub is the public key of the 2126// signee and priv is the private key of the signer. 2127// 2128// The returned slice is the certificate in DER encoding. 2129// 2130// The currently supported key types are *rsa.PublicKey, *ecdsa.PublicKey and 2131// ed25519.PublicKey. pub must be a supported key type, and priv must be a 2132// crypto.Signer with a supported public key. 2133// 2134// The AuthorityKeyId will be taken from the SubjectKeyId of parent, if any, 2135// unless the resulting certificate is self-signed. Otherwise the value from 2136// template will be used. 2137// 2138// If SubjectKeyId from template is empty and the template is a CA, SubjectKeyId 2139// will be generated from the hash of the public key. 2140func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv interface{}) (cert []byte, err error) { 2141 key, ok := priv.(crypto.Signer) 2142 if !ok { 2143 return nil, errors.New("x509: certificate private key does not implement crypto.Signer") 2144 } 2145 2146 if template.SerialNumber == nil { 2147 return nil, errors.New("x509: no SerialNumber given") 2148 } 2149 2150 if template.BasicConstraintsValid && !template.IsCA && template.MaxPathLen != -1 && (template.MaxPathLen != 0 || template.MaxPathLenZero) { 2151 return nil, errors.New("x509: only CAs are allowed to specify MaxPathLen") 2152 } 2153 2154 hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(key.Public(), template.SignatureAlgorithm) 2155 if err != nil { 2156 return nil, err 2157 } 2158 2159 publicKeyBytes, publicKeyAlgorithm, err := marshalPublicKey(pub) 2160 if err != nil { 2161 return nil, err 2162 } 2163 2164 asn1Issuer, err := subjectBytes(parent) 2165 if err != nil { 2166 return 2167 } 2168 2169 asn1Subject, err := subjectBytes(template) 2170 if err != nil { 2171 return 2172 } 2173 2174 authorityKeyId := template.AuthorityKeyId 2175 if !bytes.Equal(asn1Issuer, asn1Subject) && len(parent.SubjectKeyId) > 0 { 2176 authorityKeyId = parent.SubjectKeyId 2177 } 2178 2179 subjectKeyId := template.SubjectKeyId 2180 if len(subjectKeyId) == 0 && template.IsCA { 2181 // SubjectKeyId generated using method 1 in RFC 5280, Section 4.2.1.2: 2182 // (1) The keyIdentifier is composed of the 160-bit SHA-1 hash of the 2183 // value of the BIT STRING subjectPublicKey (excluding the tag, 2184 // length, and number of unused bits). 2185 h := sha1.Sum(publicKeyBytes) 2186 subjectKeyId = h[:] 2187 } 2188 2189 extensions, err := buildCertExtensions(template, bytes.Equal(asn1Subject, emptyASN1Subject), authorityKeyId, subjectKeyId) 2190 if err != nil { 2191 return 2192 } 2193 2194 encodedPublicKey := asn1.BitString{BitLength: len(publicKeyBytes) * 8, Bytes: publicKeyBytes} 2195 c := tbsCertificate{ 2196 Version: 2, 2197 SerialNumber: template.SerialNumber, 2198 SignatureAlgorithm: signatureAlgorithm, 2199 Issuer: asn1.RawValue{FullBytes: asn1Issuer}, 2200 Validity: validity{template.NotBefore.UTC(), template.NotAfter.UTC()}, 2201 Subject: asn1.RawValue{FullBytes: asn1Subject}, 2202 PublicKey: publicKeyInfo{nil, publicKeyAlgorithm, encodedPublicKey}, 2203 Extensions: extensions, 2204 } 2205 2206 tbsCertContents, err := asn1.Marshal(c) 2207 if err != nil { 2208 return 2209 } 2210 c.Raw = tbsCertContents 2211 2212 signed := tbsCertContents 2213 if hashFunc != 0 { 2214 h := hashFunc.New() 2215 h.Write(signed) 2216 signed = h.Sum(nil) 2217 } 2218 2219 var signerOpts crypto.SignerOpts = hashFunc 2220 if template.SignatureAlgorithm != 0 && template.SignatureAlgorithm.isRSAPSS() { 2221 signerOpts = &rsa.PSSOptions{ 2222 SaltLength: rsa.PSSSaltLengthEqualsHash, 2223 Hash: hashFunc, 2224 } 2225 } 2226 2227 var signature []byte 2228 signature, err = key.Sign(rand, signed, signerOpts) 2229 if err != nil { 2230 return 2231 } 2232 2233 signedCert, err := asn1.Marshal(certificate{ 2234 nil, 2235 c, 2236 signatureAlgorithm, 2237 asn1.BitString{Bytes: signature, BitLength: len(signature) * 8}, 2238 }) 2239 if err != nil { 2240 return nil, err 2241 } 2242 2243 // Check the signature to ensure the crypto.Signer behaved correctly. 2244 // We skip this check if the signature algorithm is MD5WithRSA as we 2245 // only support this algorithm for signing, and not verification. 2246 if sigAlg := getSignatureAlgorithmFromAI(signatureAlgorithm); sigAlg != MD5WithRSA { 2247 if err := checkSignature(sigAlg, c.Raw, signature, key.Public()); err != nil { 2248 return nil, fmt.Errorf("x509: signature over certificate returned by signer is invalid: %w", err) 2249 } 2250 } 2251 2252 return signedCert, nil 2253} 2254 2255// pemCRLPrefix is the magic string that indicates that we have a PEM encoded 2256// CRL. 2257var pemCRLPrefix = []byte("-----BEGIN X509 CRL") 2258 2259// pemType is the type of a PEM encoded CRL. 2260var pemType = "X509 CRL" 2261 2262// ParseCRL parses a CRL from the given bytes. It's often the case that PEM 2263// encoded CRLs will appear where they should be DER encoded, so this function 2264// will transparently handle PEM encoding as long as there isn't any leading 2265// garbage. 2266func ParseCRL(crlBytes []byte) (*pkix.CertificateList, error) { 2267 if bytes.HasPrefix(crlBytes, pemCRLPrefix) { 2268 block, _ := pem.Decode(crlBytes) 2269 if block != nil && block.Type == pemType { 2270 crlBytes = block.Bytes 2271 } 2272 } 2273 return ParseDERCRL(crlBytes) 2274} 2275 2276// ParseDERCRL parses a DER encoded CRL from the given bytes. 2277func ParseDERCRL(derBytes []byte) (*pkix.CertificateList, error) { 2278 certList := new(pkix.CertificateList) 2279 if rest, err := asn1.Unmarshal(derBytes, certList); err != nil { 2280 return nil, err 2281 } else if len(rest) != 0 { 2282 return nil, errors.New("x509: trailing data after CRL") 2283 } 2284 return certList, nil 2285} 2286 2287// CreateCRL returns a DER encoded CRL, signed by this Certificate, that 2288// contains the given list of revoked certificates. 2289// 2290// Note: this method does not generate an RFC 5280 conformant X.509 v2 CRL. 2291// To generate a standards compliant CRL, use CreateRevocationList instead. 2292func (c *Certificate) CreateCRL(rand io.Reader, priv interface{}, revokedCerts []pkix.RevokedCertificate, now, expiry time.Time) (crlBytes []byte, err error) { 2293 key, ok := priv.(crypto.Signer) 2294 if !ok { 2295 return nil, errors.New("x509: certificate private key does not implement crypto.Signer") 2296 } 2297 2298 hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(key.Public(), 0) 2299 if err != nil { 2300 return nil, err 2301 } 2302 2303 // Force revocation times to UTC per RFC 5280. 2304 revokedCertsUTC := make([]pkix.RevokedCertificate, len(revokedCerts)) 2305 for i, rc := range revokedCerts { 2306 rc.RevocationTime = rc.RevocationTime.UTC() 2307 revokedCertsUTC[i] = rc 2308 } 2309 2310 tbsCertList := pkix.TBSCertificateList{ 2311 Version: 1, 2312 Signature: signatureAlgorithm, 2313 Issuer: c.Subject.ToRDNSequence(), 2314 ThisUpdate: now.UTC(), 2315 NextUpdate: expiry.UTC(), 2316 RevokedCertificates: revokedCertsUTC, 2317 } 2318 2319 // Authority Key Id 2320 if len(c.SubjectKeyId) > 0 { 2321 var aki pkix.Extension 2322 aki.Id = oidExtensionAuthorityKeyId 2323 aki.Value, err = asn1.Marshal(authKeyId{Id: c.SubjectKeyId}) 2324 if err != nil { 2325 return 2326 } 2327 tbsCertList.Extensions = append(tbsCertList.Extensions, aki) 2328 } 2329 2330 tbsCertListContents, err := asn1.Marshal(tbsCertList) 2331 if err != nil { 2332 return 2333 } 2334 2335 signed := tbsCertListContents 2336 if hashFunc != 0 { 2337 h := hashFunc.New() 2338 h.Write(signed) 2339 signed = h.Sum(nil) 2340 } 2341 2342 var signature []byte 2343 signature, err = key.Sign(rand, signed, hashFunc) 2344 if err != nil { 2345 return 2346 } 2347 2348 return asn1.Marshal(pkix.CertificateList{ 2349 TBSCertList: tbsCertList, 2350 SignatureAlgorithm: signatureAlgorithm, 2351 SignatureValue: asn1.BitString{Bytes: signature, BitLength: len(signature) * 8}, 2352 }) 2353} 2354 2355// CertificateRequest represents a PKCS #10, certificate signature request. 2356type CertificateRequest struct { 2357 Raw []byte // Complete ASN.1 DER content (CSR, signature algorithm and signature). 2358 RawTBSCertificateRequest []byte // Certificate request info part of raw ASN.1 DER content. 2359 RawSubjectPublicKeyInfo []byte // DER encoded SubjectPublicKeyInfo. 2360 RawSubject []byte // DER encoded Subject. 2361 2362 Version int 2363 Signature []byte 2364 SignatureAlgorithm SignatureAlgorithm 2365 2366 PublicKeyAlgorithm PublicKeyAlgorithm 2367 PublicKey interface{} 2368 2369 Subject pkix.Name 2370 2371 // Attributes contains the CSR attributes that can parse as 2372 // pkix.AttributeTypeAndValueSET. 2373 // 2374 // Deprecated: Use Extensions and ExtraExtensions instead for parsing and 2375 // generating the requestedExtensions attribute. 2376 Attributes []pkix.AttributeTypeAndValueSET 2377 2378 // Extensions contains all requested extensions, in raw form. When parsing 2379 // CSRs, this can be used to extract extensions that are not parsed by this 2380 // package. 2381 Extensions []pkix.Extension 2382 2383 // ExtraExtensions contains extensions to be copied, raw, into any CSR 2384 // marshaled by CreateCertificateRequest. Values override any extensions 2385 // that would otherwise be produced based on the other fields but are 2386 // overridden by any extensions specified in Attributes. 2387 // 2388 // The ExtraExtensions field is not populated by ParseCertificateRequest, 2389 // see Extensions instead. 2390 ExtraExtensions []pkix.Extension 2391 2392 // Subject Alternate Name values. 2393 DNSNames []string 2394 EmailAddresses []string 2395 IPAddresses []net.IP 2396 URIs []*url.URL 2397} 2398 2399// These structures reflect the ASN.1 structure of X.509 certificate 2400// signature requests (see RFC 2986): 2401 2402type tbsCertificateRequest struct { 2403 Raw asn1.RawContent 2404 Version int 2405 Subject asn1.RawValue 2406 PublicKey publicKeyInfo 2407 RawAttributes []asn1.RawValue `asn1:"tag:0"` 2408} 2409 2410type certificateRequest struct { 2411 Raw asn1.RawContent 2412 TBSCSR tbsCertificateRequest 2413 SignatureAlgorithm pkix.AlgorithmIdentifier 2414 SignatureValue asn1.BitString 2415} 2416 2417// oidExtensionRequest is a PKCS #9 OBJECT IDENTIFIER that indicates requested 2418// extensions in a CSR. 2419var oidExtensionRequest = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 9, 14} 2420 2421// newRawAttributes converts AttributeTypeAndValueSETs from a template 2422// CertificateRequest's Attributes into tbsCertificateRequest RawAttributes. 2423func newRawAttributes(attributes []pkix.AttributeTypeAndValueSET) ([]asn1.RawValue, error) { 2424 var rawAttributes []asn1.RawValue 2425 b, err := asn1.Marshal(attributes) 2426 if err != nil { 2427 return nil, err 2428 } 2429 rest, err := asn1.Unmarshal(b, &rawAttributes) 2430 if err != nil { 2431 return nil, err 2432 } 2433 if len(rest) != 0 { 2434 return nil, errors.New("x509: failed to unmarshal raw CSR Attributes") 2435 } 2436 return rawAttributes, nil 2437} 2438 2439// parseRawAttributes Unmarshals RawAttributes into AttributeTypeAndValueSETs. 2440func parseRawAttributes(rawAttributes []asn1.RawValue) []pkix.AttributeTypeAndValueSET { 2441 var attributes []pkix.AttributeTypeAndValueSET 2442 for _, rawAttr := range rawAttributes { 2443 var attr pkix.AttributeTypeAndValueSET 2444 rest, err := asn1.Unmarshal(rawAttr.FullBytes, &attr) 2445 // Ignore attributes that don't parse into pkix.AttributeTypeAndValueSET 2446 // (i.e.: challengePassword or unstructuredName). 2447 if err == nil && len(rest) == 0 { 2448 attributes = append(attributes, attr) 2449 } 2450 } 2451 return attributes 2452} 2453 2454// parseCSRExtensions parses the attributes from a CSR and extracts any 2455// requested extensions. 2456func parseCSRExtensions(rawAttributes []asn1.RawValue) ([]pkix.Extension, error) { 2457 // pkcs10Attribute reflects the Attribute structure from RFC 2986, Section 4.1. 2458 type pkcs10Attribute struct { 2459 Id asn1.ObjectIdentifier 2460 Values []asn1.RawValue `asn1:"set"` 2461 } 2462 2463 var ret []pkix.Extension 2464 for _, rawAttr := range rawAttributes { 2465 var attr pkcs10Attribute 2466 if rest, err := asn1.Unmarshal(rawAttr.FullBytes, &attr); err != nil || len(rest) != 0 || len(attr.Values) == 0 { 2467 // Ignore attributes that don't parse. 2468 continue 2469 } 2470 2471 if !attr.Id.Equal(oidExtensionRequest) { 2472 continue 2473 } 2474 2475 var extensions []pkix.Extension 2476 if _, err := asn1.Unmarshal(attr.Values[0].FullBytes, &extensions); err != nil { 2477 return nil, err 2478 } 2479 ret = append(ret, extensions...) 2480 } 2481 2482 return ret, nil 2483} 2484 2485// CreateCertificateRequest creates a new certificate request based on a 2486// template. The following members of template are used: 2487// 2488// - SignatureAlgorithm 2489// - Subject 2490// - DNSNames 2491// - EmailAddresses 2492// - IPAddresses 2493// - URIs 2494// - ExtraExtensions 2495// - Attributes (deprecated) 2496// 2497// priv is the private key to sign the CSR with, and the corresponding public 2498// key will be included in the CSR. It must implement crypto.Signer and its 2499// Public() method must return a *rsa.PublicKey or a *ecdsa.PublicKey or a 2500// ed25519.PublicKey. (A *rsa.PrivateKey, *ecdsa.PrivateKey or 2501// ed25519.PrivateKey satisfies this.) 2502// 2503// The returned slice is the certificate request in DER encoding. 2504func CreateCertificateRequest(rand io.Reader, template *CertificateRequest, priv interface{}) (csr []byte, err error) { 2505 key, ok := priv.(crypto.Signer) 2506 if !ok { 2507 return nil, errors.New("x509: certificate private key does not implement crypto.Signer") 2508 } 2509 2510 var hashFunc crypto.Hash 2511 var sigAlgo pkix.AlgorithmIdentifier 2512 hashFunc, sigAlgo, err = signingParamsForPublicKey(key.Public(), template.SignatureAlgorithm) 2513 if err != nil { 2514 return nil, err 2515 } 2516 2517 var publicKeyBytes []byte 2518 var publicKeyAlgorithm pkix.AlgorithmIdentifier 2519 publicKeyBytes, publicKeyAlgorithm, err = marshalPublicKey(key.Public()) 2520 if err != nil { 2521 return nil, err 2522 } 2523 2524 extensions, err := buildCSRExtensions(template) 2525 if err != nil { 2526 return nil, err 2527 } 2528 2529 // Make a copy of template.Attributes because we may alter it below. 2530 attributes := make([]pkix.AttributeTypeAndValueSET, 0, len(template.Attributes)) 2531 for _, attr := range template.Attributes { 2532 values := make([][]pkix.AttributeTypeAndValue, len(attr.Value)) 2533 copy(values, attr.Value) 2534 attributes = append(attributes, pkix.AttributeTypeAndValueSET{ 2535 Type: attr.Type, 2536 Value: values, 2537 }) 2538 } 2539 2540 extensionsAppended := false 2541 if len(extensions) > 0 { 2542 // Append the extensions to an existing attribute if possible. 2543 for _, atvSet := range attributes { 2544 if !atvSet.Type.Equal(oidExtensionRequest) || len(atvSet.Value) == 0 { 2545 continue 2546 } 2547 2548 // specifiedExtensions contains all the extensions that we 2549 // found specified via template.Attributes. 2550 specifiedExtensions := make(map[string]bool) 2551 2552 for _, atvs := range atvSet.Value { 2553 for _, atv := range atvs { 2554 specifiedExtensions[atv.Type.String()] = true 2555 } 2556 } 2557 2558 newValue := make([]pkix.AttributeTypeAndValue, 0, len(atvSet.Value[0])+len(extensions)) 2559 newValue = append(newValue, atvSet.Value[0]...) 2560 2561 for _, e := range extensions { 2562 if specifiedExtensions[e.Id.String()] { 2563 // Attributes already contained a value for 2564 // this extension and it takes priority. 2565 continue 2566 } 2567 2568 newValue = append(newValue, pkix.AttributeTypeAndValue{ 2569 // There is no place for the critical 2570 // flag in an AttributeTypeAndValue. 2571 Type: e.Id, 2572 Value: e.Value, 2573 }) 2574 } 2575 2576 atvSet.Value[0] = newValue 2577 extensionsAppended = true 2578 break 2579 } 2580 } 2581 2582 rawAttributes, err := newRawAttributes(attributes) 2583 if err != nil { 2584 return 2585 } 2586 2587 // If not included in attributes, add a new attribute for the 2588 // extensions. 2589 if len(extensions) > 0 && !extensionsAppended { 2590 attr := struct { 2591 Type asn1.ObjectIdentifier 2592 Value [][]pkix.Extension `asn1:"set"` 2593 }{ 2594 Type: oidExtensionRequest, 2595 Value: [][]pkix.Extension{extensions}, 2596 } 2597 2598 b, err := asn1.Marshal(attr) 2599 if err != nil { 2600 return nil, errors.New("x509: failed to serialise extensions attribute: " + err.Error()) 2601 } 2602 2603 var rawValue asn1.RawValue 2604 if _, err := asn1.Unmarshal(b, &rawValue); err != nil { 2605 return nil, err 2606 } 2607 2608 rawAttributes = append(rawAttributes, rawValue) 2609 } 2610 2611 asn1Subject := template.RawSubject 2612 if len(asn1Subject) == 0 { 2613 asn1Subject, err = asn1.Marshal(template.Subject.ToRDNSequence()) 2614 if err != nil { 2615 return nil, err 2616 } 2617 } 2618 2619 tbsCSR := tbsCertificateRequest{ 2620 Version: 0, // PKCS #10, RFC 2986 2621 Subject: asn1.RawValue{FullBytes: asn1Subject}, 2622 PublicKey: publicKeyInfo{ 2623 Algorithm: publicKeyAlgorithm, 2624 PublicKey: asn1.BitString{ 2625 Bytes: publicKeyBytes, 2626 BitLength: len(publicKeyBytes) * 8, 2627 }, 2628 }, 2629 RawAttributes: rawAttributes, 2630 } 2631 2632 tbsCSRContents, err := asn1.Marshal(tbsCSR) 2633 if err != nil { 2634 return 2635 } 2636 tbsCSR.Raw = tbsCSRContents 2637 2638 signed := tbsCSRContents 2639 if hashFunc != 0 { 2640 h := hashFunc.New() 2641 h.Write(signed) 2642 signed = h.Sum(nil) 2643 } 2644 2645 var signature []byte 2646 signature, err = key.Sign(rand, signed, hashFunc) 2647 if err != nil { 2648 return 2649 } 2650 2651 return asn1.Marshal(certificateRequest{ 2652 TBSCSR: tbsCSR, 2653 SignatureAlgorithm: sigAlgo, 2654 SignatureValue: asn1.BitString{ 2655 Bytes: signature, 2656 BitLength: len(signature) * 8, 2657 }, 2658 }) 2659} 2660 2661// ParseCertificateRequest parses a single certificate request from the 2662// given ASN.1 DER data. 2663func ParseCertificateRequest(asn1Data []byte) (*CertificateRequest, error) { 2664 var csr certificateRequest 2665 2666 rest, err := asn1.Unmarshal(asn1Data, &csr) 2667 if err != nil { 2668 return nil, err 2669 } else if len(rest) != 0 { 2670 return nil, asn1.SyntaxError{Msg: "trailing data"} 2671 } 2672 2673 return parseCertificateRequest(&csr) 2674} 2675 2676func parseCertificateRequest(in *certificateRequest) (*CertificateRequest, error) { 2677 out := &CertificateRequest{ 2678 Raw: in.Raw, 2679 RawTBSCertificateRequest: in.TBSCSR.Raw, 2680 RawSubjectPublicKeyInfo: in.TBSCSR.PublicKey.Raw, 2681 RawSubject: in.TBSCSR.Subject.FullBytes, 2682 2683 Signature: in.SignatureValue.RightAlign(), 2684 SignatureAlgorithm: getSignatureAlgorithmFromAI(in.SignatureAlgorithm), 2685 2686 PublicKeyAlgorithm: getPublicKeyAlgorithmFromOID(in.TBSCSR.PublicKey.Algorithm.Algorithm), 2687 2688 Version: in.TBSCSR.Version, 2689 Attributes: parseRawAttributes(in.TBSCSR.RawAttributes), 2690 } 2691 2692 var err error 2693 out.PublicKey, err = parsePublicKey(out.PublicKeyAlgorithm, &in.TBSCSR.PublicKey) 2694 if err != nil { 2695 return nil, err 2696 } 2697 2698 var subject pkix.RDNSequence 2699 if rest, err := asn1.Unmarshal(in.TBSCSR.Subject.FullBytes, &subject); err != nil { 2700 return nil, err 2701 } else if len(rest) != 0 { 2702 return nil, errors.New("x509: trailing data after X.509 Subject") 2703 } 2704 2705 out.Subject.FillFromRDNSequence(&subject) 2706 2707 if out.Extensions, err = parseCSRExtensions(in.TBSCSR.RawAttributes); err != nil { 2708 return nil, err 2709 } 2710 2711 for _, extension := range out.Extensions { 2712 switch { 2713 case extension.Id.Equal(oidExtensionSubjectAltName): 2714 out.DNSNames, out.EmailAddresses, out.IPAddresses, out.URIs, err = parseSANExtension(extension.Value) 2715 if err != nil { 2716 return nil, err 2717 } 2718 } 2719 } 2720 2721 return out, nil 2722} 2723 2724// CheckSignature reports whether the signature on c is valid. 2725func (c *CertificateRequest) CheckSignature() error { 2726 return checkSignature(c.SignatureAlgorithm, c.RawTBSCertificateRequest, c.Signature, c.PublicKey) 2727} 2728 2729// RevocationList contains the fields used to create an X.509 v2 Certificate 2730// Revocation list with CreateRevocationList. 2731type RevocationList struct { 2732 // SignatureAlgorithm is used to determine the signature algorithm to be 2733 // used when signing the CRL. If 0 the default algorithm for the signing 2734 // key will be used. 2735 SignatureAlgorithm SignatureAlgorithm 2736 2737 // RevokedCertificates is used to populate the revokedCertificates 2738 // sequence in the CRL, it may be empty. RevokedCertificates may be nil, 2739 // in which case an empty CRL will be created. 2740 RevokedCertificates []pkix.RevokedCertificate 2741 2742 // Number is used to populate the X.509 v2 cRLNumber extension in the CRL, 2743 // which should be a monotonically increasing sequence number for a given 2744 // CRL scope and CRL issuer. 2745 Number *big.Int 2746 // ThisUpdate is used to populate the thisUpdate field in the CRL, which 2747 // indicates the issuance date of the CRL. 2748 ThisUpdate time.Time 2749 // NextUpdate is used to populate the nextUpdate field in the CRL, which 2750 // indicates the date by which the next CRL will be issued. NextUpdate 2751 // must be greater than ThisUpdate. 2752 NextUpdate time.Time 2753 // ExtraExtensions contains any additional extensions to add directly to 2754 // the CRL. 2755 ExtraExtensions []pkix.Extension 2756} 2757 2758// CreateRevocationList creates a new X.509 v2 Certificate Revocation List, 2759// according to RFC 5280, based on template. 2760// 2761// The CRL is signed by priv which should be the private key associated with 2762// the public key in the issuer certificate. 2763// 2764// The issuer may not be nil, and the crlSign bit must be set in KeyUsage in 2765// order to use it as a CRL issuer. 2766// 2767// The issuer distinguished name CRL field and authority key identifier 2768// extension are populated using the issuer certificate. issuer must have 2769// SubjectKeyId set. 2770func CreateRevocationList(rand io.Reader, template *RevocationList, issuer *Certificate, priv crypto.Signer) ([]byte, error) { 2771 if template == nil { 2772 return nil, errors.New("x509: template can not be nil") 2773 } 2774 if issuer == nil { 2775 return nil, errors.New("x509: issuer can not be nil") 2776 } 2777 if (issuer.KeyUsage & KeyUsageCRLSign) == 0 { 2778 return nil, errors.New("x509: issuer must have the crlSign key usage bit set") 2779 } 2780 if len(issuer.SubjectKeyId) == 0 { 2781 return nil, errors.New("x509: issuer certificate doesn't contain a subject key identifier") 2782 } 2783 if template.NextUpdate.Before(template.ThisUpdate) { 2784 return nil, errors.New("x509: template.ThisUpdate is after template.NextUpdate") 2785 } 2786 if template.Number == nil { 2787 return nil, errors.New("x509: template contains nil Number field") 2788 } 2789 2790 hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(priv.Public(), template.SignatureAlgorithm) 2791 if err != nil { 2792 return nil, err 2793 } 2794 2795 // Force revocation times to UTC per RFC 5280. 2796 revokedCertsUTC := make([]pkix.RevokedCertificate, len(template.RevokedCertificates)) 2797 for i, rc := range template.RevokedCertificates { 2798 rc.RevocationTime = rc.RevocationTime.UTC() 2799 revokedCertsUTC[i] = rc 2800 } 2801 2802 aki, err := asn1.Marshal(authKeyId{Id: issuer.SubjectKeyId}) 2803 if err != nil { 2804 return nil, err 2805 } 2806 crlNum, err := asn1.Marshal(template.Number) 2807 if err != nil { 2808 return nil, err 2809 } 2810 2811 tbsCertList := pkix.TBSCertificateList{ 2812 Version: 1, // v2 2813 Signature: signatureAlgorithm, 2814 Issuer: issuer.Subject.ToRDNSequence(), 2815 ThisUpdate: template.ThisUpdate.UTC(), 2816 NextUpdate: template.NextUpdate.UTC(), 2817 Extensions: []pkix.Extension{ 2818 { 2819 Id: oidExtensionAuthorityKeyId, 2820 Value: aki, 2821 }, 2822 { 2823 Id: oidExtensionCRLNumber, 2824 Value: crlNum, 2825 }, 2826 }, 2827 } 2828 if len(revokedCertsUTC) > 0 { 2829 tbsCertList.RevokedCertificates = revokedCertsUTC 2830 } 2831 2832 if len(template.ExtraExtensions) > 0 { 2833 tbsCertList.Extensions = append(tbsCertList.Extensions, template.ExtraExtensions...) 2834 } 2835 2836 tbsCertListContents, err := asn1.Marshal(tbsCertList) 2837 if err != nil { 2838 return nil, err 2839 } 2840 2841 input := tbsCertListContents 2842 if hashFunc != 0 { 2843 h := hashFunc.New() 2844 h.Write(tbsCertListContents) 2845 input = h.Sum(nil) 2846 } 2847 var signerOpts crypto.SignerOpts = hashFunc 2848 if template.SignatureAlgorithm.isRSAPSS() { 2849 signerOpts = &rsa.PSSOptions{ 2850 SaltLength: rsa.PSSSaltLengthEqualsHash, 2851 Hash: hashFunc, 2852 } 2853 } 2854 2855 signature, err := priv.Sign(rand, input, signerOpts) 2856 if err != nil { 2857 return nil, err 2858 } 2859 2860 return asn1.Marshal(pkix.CertificateList{ 2861 TBSCertList: tbsCertList, 2862 SignatureAlgorithm: signatureAlgorithm, 2863 SignatureValue: asn1.BitString{Bytes: signature, BitLength: len(signature) * 8}, 2864 }) 2865} 2866