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.
5 // Package x509 parses X.509-encoded keys and certificates.
30 // Explicitly import these for their crypto.RegisterHash init side-effects.
31 // Keep these as blank imports, even if they're imported above.
36 "golang.org/x/crypto/cryptobyte"
37 cryptobyte_asn1 "golang.org/x/crypto/cryptobyte/asn1"
40 // pkixPublicKey reflects a PKIX public key structure. See SubjectPublicKeyInfo
42 type pkixPublicKey struct {
43 Algo pkix.AlgorithmIdentifier
44 BitString asn1.BitString
47 // ParsePKIXPublicKey parses a public key in PKIX, ASN.1 DER form.
48 // The encoded public key is a SubjectPublicKeyInfo structure
49 // (see RFC 5280, Section 4.1).
51 // It returns a *rsa.PublicKey, *dsa.PublicKey, *ecdsa.PublicKey, or
52 // ed25519.PublicKey. More types might be supported in the future.
54 // This kind of key is commonly encoded in PEM blocks of type "PUBLIC KEY".
55 func ParsePKIXPublicKey(derBytes []byte) (pub any, err error) {
57 if rest, err := asn1.Unmarshal(derBytes, &pki); err != nil {
58 if _, err := asn1.Unmarshal(derBytes, &pkcs1PublicKey{}); err == nil {
59 return nil, errors.New("x509: failed to parse public key (use ParsePKCS1PublicKey instead for this key format)")
62 } else if len(rest) != 0 {
63 return nil, errors.New("x509: trailing data after ASN.1 of public-key")
65 algo := getPublicKeyAlgorithmFromOID(pki.Algorithm.Algorithm)
66 if algo == UnknownPublicKeyAlgorithm {
67 return nil, errors.New("x509: unknown public key algorithm")
69 return parsePublicKey(algo, &pki)
72 func marshalPublicKey(pub any) (publicKeyBytes []byte, publicKeyAlgorithm pkix.AlgorithmIdentifier, err error) {
73 switch pub := pub.(type) {
75 publicKeyBytes, err = asn1.Marshal(pkcs1PublicKey{
80 return nil, pkix.AlgorithmIdentifier{}, err
82 publicKeyAlgorithm.Algorithm = oidPublicKeyRSA
83 // This is a NULL parameters value which is required by
84 // RFC 3279, Section 2.3.1.
85 publicKeyAlgorithm.Parameters = asn1.NullRawValue
86 case *ecdsa.PublicKey:
87 oid, ok := oidFromNamedCurve(pub.Curve)
89 return nil, pkix.AlgorithmIdentifier{}, errors.New("x509: unsupported elliptic curve")
91 if !pub.Curve.IsOnCurve(pub.X, pub.Y) {
92 return nil, pkix.AlgorithmIdentifier{}, errors.New("x509: invalid elliptic curve public key")
94 publicKeyBytes = elliptic.Marshal(pub.Curve, pub.X, pub.Y)
95 publicKeyAlgorithm.Algorithm = oidPublicKeyECDSA
97 paramBytes, err = asn1.Marshal(oid)
101 publicKeyAlgorithm.Parameters.FullBytes = paramBytes
102 case ed25519.PublicKey:
104 publicKeyAlgorithm.Algorithm = oidPublicKeyEd25519
106 return nil, pkix.AlgorithmIdentifier{}, fmt.Errorf("x509: unsupported public key type: %T", pub)
109 return publicKeyBytes, publicKeyAlgorithm, nil
112 // MarshalPKIXPublicKey converts a public key to PKIX, ASN.1 DER form.
113 // The encoded public key is a SubjectPublicKeyInfo structure
114 // (see RFC 5280, Section 4.1).
116 // The following key types are currently supported: *rsa.PublicKey, *ecdsa.PublicKey
117 // and ed25519.PublicKey. Unsupported key types result in an error.
119 // This kind of key is commonly encoded in PEM blocks of type "PUBLIC KEY".
120 func MarshalPKIXPublicKey(pub any) ([]byte, error) {
121 var publicKeyBytes []byte
122 var publicKeyAlgorithm pkix.AlgorithmIdentifier
125 if publicKeyBytes, publicKeyAlgorithm, err = marshalPublicKey(pub); err != nil {
129 pkix := pkixPublicKey{
130 Algo: publicKeyAlgorithm,
131 BitString: asn1.BitString{
132 Bytes: publicKeyBytes,
133 BitLength: 8 * len(publicKeyBytes),
137 ret, _ := asn1.Marshal(pkix)
141 // These structures reflect the ASN.1 structure of X.509 certificates.:
143 type certificate struct {
145 TBSCertificate tbsCertificate
146 SignatureAlgorithm pkix.AlgorithmIdentifier
147 SignatureValue asn1.BitString
150 type tbsCertificate struct {
152 Version int `asn1:"optional,explicit,default:0,tag:0"`
153 SerialNumber *big.Int
154 SignatureAlgorithm pkix.AlgorithmIdentifier
157 Subject asn1.RawValue
158 PublicKey publicKeyInfo
159 UniqueId asn1.BitString `asn1:"optional,tag:1"`
160 SubjectUniqueId asn1.BitString `asn1:"optional,tag:2"`
161 Extensions []pkix.Extension `asn1:"omitempty,optional,explicit,tag:3"`
164 type dsaAlgorithmParameters struct {
168 type validity struct {
169 NotBefore, NotAfter time.Time
172 type publicKeyInfo struct {
174 Algorithm pkix.AlgorithmIdentifier
175 PublicKey asn1.BitString
179 type authKeyId struct {
180 Id []byte `asn1:"optional,tag:0"`
183 type SignatureAlgorithm int
186 UnknownSignatureAlgorithm SignatureAlgorithm = iota
188 MD2WithRSA // Unsupported.
189 MD5WithRSA // Only supported for signing, not verification.
190 SHA1WithRSA // Only supported for signing, and verification of CRLs, CSRs, and OCSP responses.
194 DSAWithSHA1 // Unsupported.
195 DSAWithSHA256 // Unsupported.
196 ECDSAWithSHA1 // Only supported for signing, and verification of CRLs, CSRs, and OCSP responses.
206 func (algo SignatureAlgorithm) isRSAPSS() bool {
208 case SHA256WithRSAPSS, SHA384WithRSAPSS, SHA512WithRSAPSS:
215 func (algo SignatureAlgorithm) String() string {
216 for _, details := range signatureAlgorithmDetails {
217 if details.algo == algo {
221 return strconv.Itoa(int(algo))
224 type PublicKeyAlgorithm int
227 UnknownPublicKeyAlgorithm PublicKeyAlgorithm = iota
234 var publicKeyAlgoName = [...]string{
241 func (algo PublicKeyAlgorithm) String() string {
242 if 0 < algo && int(algo) < len(publicKeyAlgoName) {
243 return publicKeyAlgoName[algo]
245 return strconv.Itoa(int(algo))
248 // OIDs for signature algorithms
250 // pkcs-1 OBJECT IDENTIFIER ::= {
251 // iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 1 }
253 // RFC 3279 2.2.1 RSA Signature Algorithms
255 // md2WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 2 }
257 // md5WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 4 }
259 // sha-1WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 5 }
261 // dsaWithSha1 OBJECT IDENTIFIER ::= {
262 // iso(1) member-body(2) us(840) x9-57(10040) x9cm(4) 3 }
264 // RFC 3279 2.2.3 ECDSA Signature Algorithm
266 // ecdsa-with-SHA1 OBJECT IDENTIFIER ::= {
267 // iso(1) member-body(2) us(840) ansi-x962(10045)
268 // signatures(4) ecdsa-with-SHA1(1)}
270 // RFC 4055 5 PKCS #1 Version 1.5
272 // sha256WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 11 }
274 // sha384WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 12 }
276 // sha512WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 13 }
278 // RFC 5758 3.1 DSA Signature Algorithms
280 // dsaWithSha256 OBJECT IDENTIFIER ::= {
281 // joint-iso-ccitt(2) country(16) us(840) organization(1) gov(101)
282 // csor(3) algorithms(4) id-dsa-with-sha2(3) 2}
284 // RFC 5758 3.2 ECDSA Signature Algorithm
286 // ecdsa-with-SHA256 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
287 // us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 2 }
289 // ecdsa-with-SHA384 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
290 // us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 3 }
292 // ecdsa-with-SHA512 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
293 // us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 4 }
295 // RFC 8410 3 Curve25519 and Curve448 Algorithm Identifiers
297 // id-Ed25519 OBJECT IDENTIFIER ::= { 1 3 101 112 }
299 oidSignatureMD2WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 2}
300 oidSignatureMD5WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 4}
301 oidSignatureSHA1WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 5}
302 oidSignatureSHA256WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 11}
303 oidSignatureSHA384WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 12}
304 oidSignatureSHA512WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 13}
305 oidSignatureRSAPSS = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 10}
306 oidSignatureDSAWithSHA1 = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 3}
307 oidSignatureDSAWithSHA256 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 3, 2}
308 oidSignatureECDSAWithSHA1 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 1}
309 oidSignatureECDSAWithSHA256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 2}
310 oidSignatureECDSAWithSHA384 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 3}
311 oidSignatureECDSAWithSHA512 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 4}
312 oidSignatureEd25519 = asn1.ObjectIdentifier{1, 3, 101, 112}
314 oidSHA256 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 1}
315 oidSHA384 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 2}
316 oidSHA512 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 3}
318 oidMGF1 = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 8}
320 // oidISOSignatureSHA1WithRSA means the same as oidSignatureSHA1WithRSA
321 // but it's specified by ISO. Microsoft's makecert.exe has been known
322 // to produce certificates with this OID.
323 oidISOSignatureSHA1WithRSA = asn1.ObjectIdentifier{1, 3, 14, 3, 2, 29}
326 var signatureAlgorithmDetails = []struct {
327 algo SignatureAlgorithm
329 oid asn1.ObjectIdentifier
330 pubKeyAlgo PublicKeyAlgorithm
333 {MD2WithRSA, "MD2-RSA", oidSignatureMD2WithRSA, RSA, crypto.Hash(0) /* no value for MD2 */},
334 {MD5WithRSA, "MD5-RSA", oidSignatureMD5WithRSA, RSA, crypto.MD5},
335 {SHA1WithRSA, "SHA1-RSA", oidSignatureSHA1WithRSA, RSA, crypto.SHA1},
336 {SHA1WithRSA, "SHA1-RSA", oidISOSignatureSHA1WithRSA, RSA, crypto.SHA1},
337 {SHA256WithRSA, "SHA256-RSA", oidSignatureSHA256WithRSA, RSA, crypto.SHA256},
338 {SHA384WithRSA, "SHA384-RSA", oidSignatureSHA384WithRSA, RSA, crypto.SHA384},
339 {SHA512WithRSA, "SHA512-RSA", oidSignatureSHA512WithRSA, RSA, crypto.SHA512},
340 {SHA256WithRSAPSS, "SHA256-RSAPSS", oidSignatureRSAPSS, RSA, crypto.SHA256},
341 {SHA384WithRSAPSS, "SHA384-RSAPSS", oidSignatureRSAPSS, RSA, crypto.SHA384},
342 {SHA512WithRSAPSS, "SHA512-RSAPSS", oidSignatureRSAPSS, RSA, crypto.SHA512},
343 {DSAWithSHA1, "DSA-SHA1", oidSignatureDSAWithSHA1, DSA, crypto.SHA1},
344 {DSAWithSHA256, "DSA-SHA256", oidSignatureDSAWithSHA256, DSA, crypto.SHA256},
345 {ECDSAWithSHA1, "ECDSA-SHA1", oidSignatureECDSAWithSHA1, ECDSA, crypto.SHA1},
346 {ECDSAWithSHA256, "ECDSA-SHA256", oidSignatureECDSAWithSHA256, ECDSA, crypto.SHA256},
347 {ECDSAWithSHA384, "ECDSA-SHA384", oidSignatureECDSAWithSHA384, ECDSA, crypto.SHA384},
348 {ECDSAWithSHA512, "ECDSA-SHA512", oidSignatureECDSAWithSHA512, ECDSA, crypto.SHA512},
349 {PureEd25519, "Ed25519", oidSignatureEd25519, Ed25519, crypto.Hash(0) /* no pre-hashing */},
352 // hashToPSSParameters contains the DER encoded RSA PSS parameters for the
353 // SHA256, SHA384, and SHA512 hashes as defined in RFC 3447, Appendix A.2.3.
354 // The parameters contain the following values:
355 // - hashAlgorithm contains the associated hash identifier with NULL parameters
356 // - maskGenAlgorithm always contains the default mgf1SHA1 identifier
357 // - saltLength contains the length of the associated hash
358 // - trailerField always contains the default trailerFieldBC value
359 var hashToPSSParameters = map[crypto.Hash]asn1.RawValue{
360 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}},
361 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}},
362 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}},
365 // pssParameters reflects the parameters in an AlgorithmIdentifier that
366 // specifies RSA PSS. See RFC 3447, Appendix A.2.3.
367 type pssParameters struct {
368 // The following three fields are not marked as
369 // optional because the default values specify SHA-1,
370 // which is no longer suitable for use in signatures.
371 Hash pkix.AlgorithmIdentifier `asn1:"explicit,tag:0"`
372 MGF pkix.AlgorithmIdentifier `asn1:"explicit,tag:1"`
373 SaltLength int `asn1:"explicit,tag:2"`
374 TrailerField int `asn1:"optional,explicit,tag:3,default:1"`
377 func getSignatureAlgorithmFromAI(ai pkix.AlgorithmIdentifier) SignatureAlgorithm {
378 if ai.Algorithm.Equal(oidSignatureEd25519) {
379 // RFC 8410, Section 3
380 // > For all of the OIDs, the parameters MUST be absent.
381 if len(ai.Parameters.FullBytes) != 0 {
382 return UnknownSignatureAlgorithm
386 if !ai.Algorithm.Equal(oidSignatureRSAPSS) {
387 for _, details := range signatureAlgorithmDetails {
388 if ai.Algorithm.Equal(details.oid) {
392 return UnknownSignatureAlgorithm
395 // RSA PSS is special because it encodes important parameters
396 // in the Parameters.
398 var params pssParameters
399 if _, err := asn1.Unmarshal(ai.Parameters.FullBytes, ¶ms); err != nil {
400 return UnknownSignatureAlgorithm
403 var mgf1HashFunc pkix.AlgorithmIdentifier
404 if _, err := asn1.Unmarshal(params.MGF.Parameters.FullBytes, &mgf1HashFunc); err != nil {
405 return UnknownSignatureAlgorithm
408 // PSS is greatly overburdened with options. This code forces them into
409 // three buckets by requiring that the MGF1 hash function always match the
410 // message hash function (as recommended in RFC 3447, Section 8.1), that the
411 // salt length matches the hash length, and that the trailer field has the
413 if (len(params.Hash.Parameters.FullBytes) != 0 && !bytes.Equal(params.Hash.Parameters.FullBytes, asn1.NullBytes)) ||
414 !params.MGF.Algorithm.Equal(oidMGF1) ||
415 !mgf1HashFunc.Algorithm.Equal(params.Hash.Algorithm) ||
416 (len(mgf1HashFunc.Parameters.FullBytes) != 0 && !bytes.Equal(mgf1HashFunc.Parameters.FullBytes, asn1.NullBytes)) ||
417 params.TrailerField != 1 {
418 return UnknownSignatureAlgorithm
422 case params.Hash.Algorithm.Equal(oidSHA256) && params.SaltLength == 32:
423 return SHA256WithRSAPSS
424 case params.Hash.Algorithm.Equal(oidSHA384) && params.SaltLength == 48:
425 return SHA384WithRSAPSS
426 case params.Hash.Algorithm.Equal(oidSHA512) && params.SaltLength == 64:
427 return SHA512WithRSAPSS
430 return UnknownSignatureAlgorithm
433 // RFC 3279, 2.3 Public Key Algorithms
435 // pkcs-1 OBJECT IDENTIFIER ::== { iso(1) member-body(2) us(840)
436 // rsadsi(113549) pkcs(1) 1 }
438 // rsaEncryption OBJECT IDENTIFIER ::== { pkcs1-1 1 }
440 // id-dsa OBJECT IDENTIFIER ::== { iso(1) member-body(2) us(840)
441 // x9-57(10040) x9cm(4) 1 }
443 // RFC 5480, 2.1.1 Unrestricted Algorithm Identifier and Parameters
445 // id-ecPublicKey OBJECT IDENTIFIER ::= {
446 // iso(1) member-body(2) us(840) ansi-X9-62(10045) keyType(2) 1 }
448 oidPublicKeyRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 1}
449 oidPublicKeyDSA = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 1}
450 oidPublicKeyECDSA = asn1.ObjectIdentifier{1, 2, 840, 10045, 2, 1}
451 oidPublicKeyEd25519 = oidSignatureEd25519
454 func getPublicKeyAlgorithmFromOID(oid asn1.ObjectIdentifier) PublicKeyAlgorithm {
456 case oid.Equal(oidPublicKeyRSA):
458 case oid.Equal(oidPublicKeyDSA):
460 case oid.Equal(oidPublicKeyECDSA):
462 case oid.Equal(oidPublicKeyEd25519):
465 return UnknownPublicKeyAlgorithm
468 // RFC 5480, 2.1.1.1. Named Curve
470 // secp224r1 OBJECT IDENTIFIER ::= {
471 // iso(1) identified-organization(3) certicom(132) curve(0) 33 }
473 // secp256r1 OBJECT IDENTIFIER ::= {
474 // iso(1) member-body(2) us(840) ansi-X9-62(10045) curves(3)
477 // secp384r1 OBJECT IDENTIFIER ::= {
478 // iso(1) identified-organization(3) certicom(132) curve(0) 34 }
480 // secp521r1 OBJECT IDENTIFIER ::= {
481 // iso(1) identified-organization(3) certicom(132) curve(0) 35 }
483 // NB: secp256r1 is equivalent to prime256v1
485 oidNamedCurveP224 = asn1.ObjectIdentifier{1, 3, 132, 0, 33}
486 oidNamedCurveP256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 3, 1, 7}
487 oidNamedCurveP384 = asn1.ObjectIdentifier{1, 3, 132, 0, 34}
488 oidNamedCurveP521 = asn1.ObjectIdentifier{1, 3, 132, 0, 35}
491 func namedCurveFromOID(oid asn1.ObjectIdentifier) elliptic.Curve {
493 case oid.Equal(oidNamedCurveP224):
494 return elliptic.P224()
495 case oid.Equal(oidNamedCurveP256):
496 return elliptic.P256()
497 case oid.Equal(oidNamedCurveP384):
498 return elliptic.P384()
499 case oid.Equal(oidNamedCurveP521):
500 return elliptic.P521()
505 func oidFromNamedCurve(curve elliptic.Curve) (asn1.ObjectIdentifier, bool) {
507 case elliptic.P224():
508 return oidNamedCurveP224, true
509 case elliptic.P256():
510 return oidNamedCurveP256, true
511 case elliptic.P384():
512 return oidNamedCurveP384, true
513 case elliptic.P521():
514 return oidNamedCurveP521, true
520 // KeyUsage represents the set of actions that are valid for a given key. It's
521 // a bitmap of the KeyUsage* constants.
525 KeyUsageDigitalSignature KeyUsage = 1 << iota
526 KeyUsageContentCommitment
527 KeyUsageKeyEncipherment
528 KeyUsageDataEncipherment
536 // RFC 5280, 4.2.1.12 Extended Key Usage
538 // anyExtendedKeyUsage OBJECT IDENTIFIER ::= { id-ce-extKeyUsage 0 }
540 // id-kp OBJECT IDENTIFIER ::= { id-pkix 3 }
542 // id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 }
543 // id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 }
544 // id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 }
545 // id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 }
546 // id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 }
547 // id-kp-OCSPSigning OBJECT IDENTIFIER ::= { id-kp 9 }
549 oidExtKeyUsageAny = asn1.ObjectIdentifier{2, 5, 29, 37, 0}
550 oidExtKeyUsageServerAuth = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 1}
551 oidExtKeyUsageClientAuth = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 2}
552 oidExtKeyUsageCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 3}
553 oidExtKeyUsageEmailProtection = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 4}
554 oidExtKeyUsageIPSECEndSystem = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 5}
555 oidExtKeyUsageIPSECTunnel = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 6}
556 oidExtKeyUsageIPSECUser = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 7}
557 oidExtKeyUsageTimeStamping = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 8}
558 oidExtKeyUsageOCSPSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 9}
559 oidExtKeyUsageMicrosoftServerGatedCrypto = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 10, 3, 3}
560 oidExtKeyUsageNetscapeServerGatedCrypto = asn1.ObjectIdentifier{2, 16, 840, 1, 113730, 4, 1}
561 oidExtKeyUsageMicrosoftCommercialCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 2, 1, 22}
562 oidExtKeyUsageMicrosoftKernelCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 61, 1, 1}
565 // ExtKeyUsage represents an extended set of actions that are valid for a given key.
566 // Each of the ExtKeyUsage* constants define a unique action.
570 ExtKeyUsageAny ExtKeyUsage = iota
571 ExtKeyUsageServerAuth
572 ExtKeyUsageClientAuth
573 ExtKeyUsageCodeSigning
574 ExtKeyUsageEmailProtection
575 ExtKeyUsageIPSECEndSystem
576 ExtKeyUsageIPSECTunnel
578 ExtKeyUsageTimeStamping
579 ExtKeyUsageOCSPSigning
580 ExtKeyUsageMicrosoftServerGatedCrypto
581 ExtKeyUsageNetscapeServerGatedCrypto
582 ExtKeyUsageMicrosoftCommercialCodeSigning
583 ExtKeyUsageMicrosoftKernelCodeSigning
586 // extKeyUsageOIDs contains the mapping between an ExtKeyUsage and its OID.
587 var extKeyUsageOIDs = []struct {
588 extKeyUsage ExtKeyUsage
589 oid asn1.ObjectIdentifier
591 {ExtKeyUsageAny, oidExtKeyUsageAny},
592 {ExtKeyUsageServerAuth, oidExtKeyUsageServerAuth},
593 {ExtKeyUsageClientAuth, oidExtKeyUsageClientAuth},
594 {ExtKeyUsageCodeSigning, oidExtKeyUsageCodeSigning},
595 {ExtKeyUsageEmailProtection, oidExtKeyUsageEmailProtection},
596 {ExtKeyUsageIPSECEndSystem, oidExtKeyUsageIPSECEndSystem},
597 {ExtKeyUsageIPSECTunnel, oidExtKeyUsageIPSECTunnel},
598 {ExtKeyUsageIPSECUser, oidExtKeyUsageIPSECUser},
599 {ExtKeyUsageTimeStamping, oidExtKeyUsageTimeStamping},
600 {ExtKeyUsageOCSPSigning, oidExtKeyUsageOCSPSigning},
601 {ExtKeyUsageMicrosoftServerGatedCrypto, oidExtKeyUsageMicrosoftServerGatedCrypto},
602 {ExtKeyUsageNetscapeServerGatedCrypto, oidExtKeyUsageNetscapeServerGatedCrypto},
603 {ExtKeyUsageMicrosoftCommercialCodeSigning, oidExtKeyUsageMicrosoftCommercialCodeSigning},
604 {ExtKeyUsageMicrosoftKernelCodeSigning, oidExtKeyUsageMicrosoftKernelCodeSigning},
607 func extKeyUsageFromOID(oid asn1.ObjectIdentifier) (eku ExtKeyUsage, ok bool) {
608 for _, pair := range extKeyUsageOIDs {
609 if oid.Equal(pair.oid) {
610 return pair.extKeyUsage, true
616 func oidFromExtKeyUsage(eku ExtKeyUsage) (oid asn1.ObjectIdentifier, ok bool) {
617 for _, pair := range extKeyUsageOIDs {
618 if eku == pair.extKeyUsage {
619 return pair.oid, true
625 // A Certificate represents an X.509 certificate.
626 type Certificate struct {
627 Raw []byte // Complete ASN.1 DER content (certificate, signature algorithm and signature).
628 RawTBSCertificate []byte // Certificate part of raw ASN.1 DER content.
629 RawSubjectPublicKeyInfo []byte // DER encoded SubjectPublicKeyInfo.
630 RawSubject []byte // DER encoded Subject
631 RawIssuer []byte // DER encoded Issuer
634 SignatureAlgorithm SignatureAlgorithm
636 PublicKeyAlgorithm PublicKeyAlgorithm
640 SerialNumber *big.Int
643 NotBefore, NotAfter time.Time // Validity bounds.
646 // Extensions contains raw X.509 extensions. When parsing certificates,
647 // this can be used to extract non-critical extensions that are not
648 // parsed by this package. When marshaling certificates, the Extensions
649 // field is ignored, see ExtraExtensions.
650 Extensions []pkix.Extension
652 // ExtraExtensions contains extensions to be copied, raw, into any
653 // marshaled certificates. Values override any extensions that would
654 // otherwise be produced based on the other fields. The ExtraExtensions
655 // field is not populated when parsing certificates, see Extensions.
656 ExtraExtensions []pkix.Extension
658 // UnhandledCriticalExtensions contains a list of extension IDs that
659 // were not (fully) processed when parsing. Verify will fail if this
660 // slice is non-empty, unless verification is delegated to an OS
661 // library which understands all the critical extensions.
663 // Users can access these extensions using Extensions and can remove
664 // elements from this slice if they believe that they have been
666 UnhandledCriticalExtensions []asn1.ObjectIdentifier
668 ExtKeyUsage []ExtKeyUsage // Sequence of extended key usages.
669 UnknownExtKeyUsage []asn1.ObjectIdentifier // Encountered extended key usages unknown to this package.
671 // BasicConstraintsValid indicates whether IsCA, MaxPathLen,
672 // and MaxPathLenZero are valid.
673 BasicConstraintsValid bool
676 // MaxPathLen and MaxPathLenZero indicate the presence and
677 // value of the BasicConstraints' "pathLenConstraint".
679 // When parsing a certificate, a positive non-zero MaxPathLen
680 // means that the field was specified, -1 means it was unset,
681 // and MaxPathLenZero being true mean that the field was
682 // explicitly set to zero. The case of MaxPathLen==0 with MaxPathLenZero==false
683 // should be treated equivalent to -1 (unset).
685 // When generating a certificate, an unset pathLenConstraint
686 // can be requested with either MaxPathLen == -1 or using the
687 // zero value for both MaxPathLen and MaxPathLenZero.
689 // MaxPathLenZero indicates that BasicConstraintsValid==true
690 // and MaxPathLen==0 should be interpreted as an actual
691 // maximum path length of zero. Otherwise, that combination is
692 // interpreted as MaxPathLen not being set.
696 AuthorityKeyId []byte
698 // RFC 5280, 4.2.2.1 (Authority Information Access)
700 IssuingCertificateURL []string
702 // Subject Alternate Name values. (Note that these values may not be valid
703 // if invalid values were contained within a parsed certificate. For
704 // example, an element of DNSNames may not be a valid DNS domain name.)
706 EmailAddresses []string
711 PermittedDNSDomainsCritical bool // if true then the name constraints are marked critical.
712 PermittedDNSDomains []string
713 ExcludedDNSDomains []string
714 PermittedIPRanges []*net.IPNet
715 ExcludedIPRanges []*net.IPNet
716 PermittedEmailAddresses []string
717 ExcludedEmailAddresses []string
718 PermittedURIDomains []string
719 ExcludedURIDomains []string
721 // CRL Distribution Points
722 CRLDistributionPoints []string
724 PolicyIdentifiers []asn1.ObjectIdentifier
727 // ErrUnsupportedAlgorithm results from attempting to perform an operation that
728 // involves algorithms that are not currently implemented.
729 var ErrUnsupportedAlgorithm = errors.New("x509: cannot verify signature: algorithm unimplemented")
731 // An InsecureAlgorithmError indicates that the SignatureAlgorithm used to
732 // generate the signature is not secure, and the signature has been rejected.
734 // To temporarily restore support for SHA-1 signatures, include the value
735 // "x509sha1=1" in the GODEBUG environment variable. Note that this option will
736 // be removed in a future release.
737 type InsecureAlgorithmError SignatureAlgorithm
739 func (e InsecureAlgorithmError) Error() string {
741 if SignatureAlgorithm(e) == SHA1WithRSA || SignatureAlgorithm(e) == ECDSAWithSHA1 {
742 override = " (temporarily override with GODEBUG=x509sha1=1)"
744 return fmt.Sprintf("x509: cannot verify signature: insecure algorithm %v", SignatureAlgorithm(e)) + override
747 // ConstraintViolationError results when a requested usage is not permitted by
748 // a certificate. For example: checking a signature when the public key isn't a
749 // certificate signing key.
750 type ConstraintViolationError struct{}
752 func (ConstraintViolationError) Error() string {
753 return "x509: invalid signature: parent certificate cannot sign this kind of certificate"
756 func (c *Certificate) Equal(other *Certificate) bool {
757 if c == nil || other == nil {
760 return bytes.Equal(c.Raw, other.Raw)
763 func (c *Certificate) hasSANExtension() bool {
764 return oidInExtensions(oidExtensionSubjectAltName, c.Extensions)
767 // CheckSignatureFrom verifies that the signature on c is a valid signature
768 // from parent. SHA1WithRSA and ECDSAWithSHA1 signatures are not supported.
769 func (c *Certificate) CheckSignatureFrom(parent *Certificate) error {
770 // RFC 5280, 4.2.1.9:
771 // "If the basic constraints extension is not present in a version 3
772 // certificate, or the extension is present but the cA boolean is not
773 // asserted, then the certified public key MUST NOT be used to verify
774 // certificate signatures."
775 if parent.Version == 3 && !parent.BasicConstraintsValid ||
776 parent.BasicConstraintsValid && !parent.IsCA {
777 return ConstraintViolationError{}
780 if parent.KeyUsage != 0 && parent.KeyUsage&KeyUsageCertSign == 0 {
781 return ConstraintViolationError{}
784 if parent.PublicKeyAlgorithm == UnknownPublicKeyAlgorithm {
785 return ErrUnsupportedAlgorithm
788 // TODO(agl): don't ignore the path length constraint.
790 return checkSignature(c.SignatureAlgorithm, c.RawTBSCertificate, c.Signature, parent.PublicKey, false)
793 // CheckSignature verifies that signature is a valid signature over signed from
795 func (c *Certificate) CheckSignature(algo SignatureAlgorithm, signed, signature []byte) error {
796 return checkSignature(algo, signed, signature, c.PublicKey, true)
799 func (c *Certificate) hasNameConstraints() bool {
800 return oidInExtensions(oidExtensionNameConstraints, c.Extensions)
803 func (c *Certificate) getSANExtension() []byte {
804 for _, e := range c.Extensions {
805 if e.Id.Equal(oidExtensionSubjectAltName) {
812 func signaturePublicKeyAlgoMismatchError(expectedPubKeyAlgo PublicKeyAlgorithm, pubKey any) error {
813 return fmt.Errorf("x509: signature algorithm specifies an %s public key, but have public key of type %T", expectedPubKeyAlgo.String(), pubKey)
816 // checkSignature verifies that signature is a valid signature over signed from
817 // a crypto.PublicKey.
818 func checkSignature(algo SignatureAlgorithm, signed, signature []byte, publicKey crypto.PublicKey, allowSHA1 bool) (err error) {
819 var hashType crypto.Hash
820 var pubKeyAlgo PublicKeyAlgorithm
822 for _, details := range signatureAlgorithmDetails {
823 if details.algo == algo {
824 hashType = details.hash
825 pubKeyAlgo = details.pubKeyAlgo
831 if pubKeyAlgo != Ed25519 {
832 return ErrUnsupportedAlgorithm
835 return InsecureAlgorithmError(algo)
837 // SHA-1 signatures are mostly disabled. See go.dev/issue/41682.
838 if !allowSHA1 && godebug.Get("x509sha1") != "1" {
839 return InsecureAlgorithmError(algo)
843 if !hashType.Available() {
844 return ErrUnsupportedAlgorithm
851 switch pub := publicKey.(type) {
853 if pubKeyAlgo != RSA {
854 return signaturePublicKeyAlgoMismatchError(pubKeyAlgo, pub)
857 return rsa.VerifyPSS(pub, hashType, signed, signature, &rsa.PSSOptions{SaltLength: rsa.PSSSaltLengthEqualsHash})
859 return rsa.VerifyPKCS1v15(pub, hashType, signed, signature)
861 case *ecdsa.PublicKey:
862 if pubKeyAlgo != ECDSA {
863 return signaturePublicKeyAlgoMismatchError(pubKeyAlgo, pub)
865 if !ecdsa.VerifyASN1(pub, signed, signature) {
866 return errors.New("x509: ECDSA verification failure")
869 case ed25519.PublicKey:
870 if pubKeyAlgo != Ed25519 {
871 return signaturePublicKeyAlgoMismatchError(pubKeyAlgo, pub)
873 if !ed25519.Verify(pub, signed, signature) {
874 return errors.New("x509: Ed25519 verification failure")
878 return ErrUnsupportedAlgorithm
881 // CheckCRLSignature checks that the signature in crl is from c.
883 // Deprecated: Use RevocationList.CheckSignatureFrom instead.
884 func (c *Certificate) CheckCRLSignature(crl *pkix.CertificateList) error {
885 algo := getSignatureAlgorithmFromAI(crl.SignatureAlgorithm)
886 return c.CheckSignature(algo, crl.TBSCertList.Raw, crl.SignatureValue.RightAlign())
889 type UnhandledCriticalExtension struct{}
891 func (h UnhandledCriticalExtension) Error() string {
892 return "x509: unhandled critical extension"
895 type basicConstraints struct {
896 IsCA bool `asn1:"optional"`
897 MaxPathLen int `asn1:"optional,default:-1"`
901 type policyInformation struct {
902 Policy asn1.ObjectIdentifier
903 // policyQualifiers omitted
914 type authorityInfoAccess struct {
915 Method asn1.ObjectIdentifier
916 Location asn1.RawValue
919 // RFC 5280, 4.2.1.14
920 type distributionPoint struct {
921 DistributionPoint distributionPointName `asn1:"optional,tag:0"`
922 Reason asn1.BitString `asn1:"optional,tag:1"`
923 CRLIssuer asn1.RawValue `asn1:"optional,tag:2"`
926 type distributionPointName struct {
927 FullName []asn1.RawValue `asn1:"optional,tag:0"`
928 RelativeName pkix.RDNSequence `asn1:"optional,tag:1"`
931 func reverseBitsInAByte(in byte) byte {
933 b2 := b1>>2&0x33 | b1<<2&0xcc
934 b3 := b2>>1&0x55 | b2<<1&0xaa
938 // asn1BitLength returns the bit-length of bitString by considering the
939 // most-significant bit in a byte to be the "first" bit. This convention
940 // matches ASN.1, but differs from almost everything else.
941 func asn1BitLength(bitString []byte) int {
942 bitLen := len(bitString) * 8
944 for i := range bitString {
945 b := bitString[len(bitString)-i-1]
947 for bit := uint(0); bit < 8; bit++ {
959 oidExtensionSubjectKeyId = []int{2, 5, 29, 14}
960 oidExtensionKeyUsage = []int{2, 5, 29, 15}
961 oidExtensionExtendedKeyUsage = []int{2, 5, 29, 37}
962 oidExtensionAuthorityKeyId = []int{2, 5, 29, 35}
963 oidExtensionBasicConstraints = []int{2, 5, 29, 19}
964 oidExtensionSubjectAltName = []int{2, 5, 29, 17}
965 oidExtensionCertificatePolicies = []int{2, 5, 29, 32}
966 oidExtensionNameConstraints = []int{2, 5, 29, 30}
967 oidExtensionCRLDistributionPoints = []int{2, 5, 29, 31}
968 oidExtensionAuthorityInfoAccess = []int{1, 3, 6, 1, 5, 5, 7, 1, 1}
969 oidExtensionCRLNumber = []int{2, 5, 29, 20}
973 oidAuthorityInfoAccessOcsp = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 48, 1}
974 oidAuthorityInfoAccessIssuers = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 48, 2}
977 // oidInExtensions reports whether an extension with the given oid exists in
979 func oidInExtensions(oid asn1.ObjectIdentifier, extensions []pkix.Extension) bool {
980 for _, e := range extensions {
988 // marshalSANs marshals a list of addresses into a the contents of an X.509
989 // SubjectAlternativeName extension.
990 func marshalSANs(dnsNames, emailAddresses []string, ipAddresses []net.IP, uris []*url.URL) (derBytes []byte, err error) {
991 var rawValues []asn1.RawValue
992 for _, name := range dnsNames {
993 if err := isIA5String(name); err != nil {
996 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeDNS, Class: 2, Bytes: []byte(name)})
998 for _, email := range emailAddresses {
999 if err := isIA5String(email); err != nil {
1002 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeEmail, Class: 2, Bytes: []byte(email)})
1004 for _, rawIP := range ipAddresses {
1005 // If possible, we always want to encode IPv4 addresses in 4 bytes.
1010 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeIP, Class: 2, Bytes: ip})
1012 for _, uri := range uris {
1013 uriStr := uri.String()
1014 if err := isIA5String(uriStr); err != nil {
1017 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeURI, Class: 2, Bytes: []byte(uriStr)})
1019 return asn1.Marshal(rawValues)
1022 func isIA5String(s string) error {
1023 for _, r := range s {
1024 // Per RFC5280 "IA5String is limited to the set of ASCII characters"
1025 if r > unicode.MaxASCII {
1026 return fmt.Errorf("x509: %q cannot be encoded as an IA5String", s)
1033 func buildCertExtensions(template *Certificate, subjectIsEmpty bool, authorityKeyId []byte, subjectKeyId []byte) (ret []pkix.Extension, err error) {
1034 ret = make([]pkix.Extension, 10 /* maximum number of elements. */)
1037 if template.KeyUsage != 0 &&
1038 !oidInExtensions(oidExtensionKeyUsage, template.ExtraExtensions) {
1039 ret[n], err = marshalKeyUsage(template.KeyUsage)
1046 if (len(template.ExtKeyUsage) > 0 || len(template.UnknownExtKeyUsage) > 0) &&
1047 !oidInExtensions(oidExtensionExtendedKeyUsage, template.ExtraExtensions) {
1048 ret[n], err = marshalExtKeyUsage(template.ExtKeyUsage, template.UnknownExtKeyUsage)
1055 if template.BasicConstraintsValid && !oidInExtensions(oidExtensionBasicConstraints, template.ExtraExtensions) {
1056 ret[n], err = marshalBasicConstraints(template.IsCA, template.MaxPathLen, template.MaxPathLenZero)
1063 if len(subjectKeyId) > 0 && !oidInExtensions(oidExtensionSubjectKeyId, template.ExtraExtensions) {
1064 ret[n].Id = oidExtensionSubjectKeyId
1065 ret[n].Value, err = asn1.Marshal(subjectKeyId)
1072 if len(authorityKeyId) > 0 && !oidInExtensions(oidExtensionAuthorityKeyId, template.ExtraExtensions) {
1073 ret[n].Id = oidExtensionAuthorityKeyId
1074 ret[n].Value, err = asn1.Marshal(authKeyId{authorityKeyId})
1081 if (len(template.OCSPServer) > 0 || len(template.IssuingCertificateURL) > 0) &&
1082 !oidInExtensions(oidExtensionAuthorityInfoAccess, template.ExtraExtensions) {
1083 ret[n].Id = oidExtensionAuthorityInfoAccess
1084 var aiaValues []authorityInfoAccess
1085 for _, name := range template.OCSPServer {
1086 aiaValues = append(aiaValues, authorityInfoAccess{
1087 Method: oidAuthorityInfoAccessOcsp,
1088 Location: asn1.RawValue{Tag: 6, Class: 2, Bytes: []byte(name)},
1091 for _, name := range template.IssuingCertificateURL {
1092 aiaValues = append(aiaValues, authorityInfoAccess{
1093 Method: oidAuthorityInfoAccessIssuers,
1094 Location: asn1.RawValue{Tag: 6, Class: 2, Bytes: []byte(name)},
1097 ret[n].Value, err = asn1.Marshal(aiaValues)
1104 if (len(template.DNSNames) > 0 || len(template.EmailAddresses) > 0 || len(template.IPAddresses) > 0 || len(template.URIs) > 0) &&
1105 !oidInExtensions(oidExtensionSubjectAltName, template.ExtraExtensions) {
1106 ret[n].Id = oidExtensionSubjectAltName
1107 // From RFC 5280, Section 4.2.1.6:
1108 // “If the subject field contains an empty sequence ... then
1109 // subjectAltName extension ... is marked as critical”
1110 ret[n].Critical = subjectIsEmpty
1111 ret[n].Value, err = marshalSANs(template.DNSNames, template.EmailAddresses, template.IPAddresses, template.URIs)
1118 if len(template.PolicyIdentifiers) > 0 &&
1119 !oidInExtensions(oidExtensionCertificatePolicies, template.ExtraExtensions) {
1120 ret[n], err = marshalCertificatePolicies(template.PolicyIdentifiers)
1127 if (len(template.PermittedDNSDomains) > 0 || len(template.ExcludedDNSDomains) > 0 ||
1128 len(template.PermittedIPRanges) > 0 || len(template.ExcludedIPRanges) > 0 ||
1129 len(template.PermittedEmailAddresses) > 0 || len(template.ExcludedEmailAddresses) > 0 ||
1130 len(template.PermittedURIDomains) > 0 || len(template.ExcludedURIDomains) > 0) &&
1131 !oidInExtensions(oidExtensionNameConstraints, template.ExtraExtensions) {
1132 ret[n].Id = oidExtensionNameConstraints
1133 ret[n].Critical = template.PermittedDNSDomainsCritical
1135 ipAndMask := func(ipNet *net.IPNet) []byte {
1136 maskedIP := ipNet.IP.Mask(ipNet.Mask)
1137 ipAndMask := make([]byte, 0, len(maskedIP)+len(ipNet.Mask))
1138 ipAndMask = append(ipAndMask, maskedIP...)
1139 ipAndMask = append(ipAndMask, ipNet.Mask...)
1143 serialiseConstraints := func(dns []string, ips []*net.IPNet, emails []string, uriDomains []string) (der []byte, err error) {
1144 var b cryptobyte.Builder
1146 for _, name := range dns {
1147 if err = isIA5String(name); err != nil {
1151 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1152 b.AddASN1(cryptobyte_asn1.Tag(2).ContextSpecific(), func(b *cryptobyte.Builder) {
1153 b.AddBytes([]byte(name))
1158 for _, ipNet := range ips {
1159 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1160 b.AddASN1(cryptobyte_asn1.Tag(7).ContextSpecific(), func(b *cryptobyte.Builder) {
1161 b.AddBytes(ipAndMask(ipNet))
1166 for _, email := range emails {
1167 if err = isIA5String(email); err != nil {
1171 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1172 b.AddASN1(cryptobyte_asn1.Tag(1).ContextSpecific(), func(b *cryptobyte.Builder) {
1173 b.AddBytes([]byte(email))
1178 for _, uriDomain := range uriDomains {
1179 if err = isIA5String(uriDomain); err != nil {
1183 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1184 b.AddASN1(cryptobyte_asn1.Tag(6).ContextSpecific(), func(b *cryptobyte.Builder) {
1185 b.AddBytes([]byte(uriDomain))
1193 permitted, err := serialiseConstraints(template.PermittedDNSDomains, template.PermittedIPRanges, template.PermittedEmailAddresses, template.PermittedURIDomains)
1198 excluded, err := serialiseConstraints(template.ExcludedDNSDomains, template.ExcludedIPRanges, template.ExcludedEmailAddresses, template.ExcludedURIDomains)
1203 var b cryptobyte.Builder
1204 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1205 if len(permitted) > 0 {
1206 b.AddASN1(cryptobyte_asn1.Tag(0).ContextSpecific().Constructed(), func(b *cryptobyte.Builder) {
1207 b.AddBytes(permitted)
1211 if len(excluded) > 0 {
1212 b.AddASN1(cryptobyte_asn1.Tag(1).ContextSpecific().Constructed(), func(b *cryptobyte.Builder) {
1213 b.AddBytes(excluded)
1218 ret[n].Value, err = b.Bytes()
1225 if len(template.CRLDistributionPoints) > 0 &&
1226 !oidInExtensions(oidExtensionCRLDistributionPoints, template.ExtraExtensions) {
1227 ret[n].Id = oidExtensionCRLDistributionPoints
1229 var crlDp []distributionPoint
1230 for _, name := range template.CRLDistributionPoints {
1231 dp := distributionPoint{
1232 DistributionPoint: distributionPointName{
1233 FullName: []asn1.RawValue{
1234 {Tag: 6, Class: 2, Bytes: []byte(name)},
1238 crlDp = append(crlDp, dp)
1241 ret[n].Value, err = asn1.Marshal(crlDp)
1248 // Adding another extension here? Remember to update the maximum number
1249 // of elements in the make() at the top of the function and the list of
1250 // template fields used in CreateCertificate documentation.
1252 return append(ret[:n], template.ExtraExtensions...), nil
1255 func marshalKeyUsage(ku KeyUsage) (pkix.Extension, error) {
1256 ext := pkix.Extension{Id: oidExtensionKeyUsage, Critical: true}
1259 a[0] = reverseBitsInAByte(byte(ku))
1260 a[1] = reverseBitsInAByte(byte(ku >> 8))
1269 ext.Value, err = asn1.Marshal(asn1.BitString{Bytes: bitString, BitLength: asn1BitLength(bitString)})
1273 func marshalExtKeyUsage(extUsages []ExtKeyUsage, unknownUsages []asn1.ObjectIdentifier) (pkix.Extension, error) {
1274 ext := pkix.Extension{Id: oidExtensionExtendedKeyUsage}
1276 oids := make([]asn1.ObjectIdentifier, len(extUsages)+len(unknownUsages))
1277 for i, u := range extUsages {
1278 if oid, ok := oidFromExtKeyUsage(u); ok {
1281 return ext, errors.New("x509: unknown extended key usage")
1285 copy(oids[len(extUsages):], unknownUsages)
1288 ext.Value, err = asn1.Marshal(oids)
1292 func marshalBasicConstraints(isCA bool, maxPathLen int, maxPathLenZero bool) (pkix.Extension, error) {
1293 ext := pkix.Extension{Id: oidExtensionBasicConstraints, Critical: true}
1294 // Leaving MaxPathLen as zero indicates that no maximum path
1295 // length is desired, unless MaxPathLenZero is set. A value of
1296 // -1 causes encoding/asn1 to omit the value as desired.
1297 if maxPathLen == 0 && !maxPathLenZero {
1301 ext.Value, err = asn1.Marshal(basicConstraints{isCA, maxPathLen})
1305 func marshalCertificatePolicies(policyIdentifiers []asn1.ObjectIdentifier) (pkix.Extension, error) {
1306 ext := pkix.Extension{Id: oidExtensionCertificatePolicies}
1307 policies := make([]policyInformation, len(policyIdentifiers))
1308 for i, policy := range policyIdentifiers {
1309 policies[i].Policy = policy
1312 ext.Value, err = asn1.Marshal(policies)
1316 func buildCSRExtensions(template *CertificateRequest) ([]pkix.Extension, error) {
1317 var ret []pkix.Extension
1319 if (len(template.DNSNames) > 0 || len(template.EmailAddresses) > 0 || len(template.IPAddresses) > 0 || len(template.URIs) > 0) &&
1320 !oidInExtensions(oidExtensionSubjectAltName, template.ExtraExtensions) {
1321 sanBytes, err := marshalSANs(template.DNSNames, template.EmailAddresses, template.IPAddresses, template.URIs)
1326 ret = append(ret, pkix.Extension{
1327 Id: oidExtensionSubjectAltName,
1332 return append(ret, template.ExtraExtensions...), nil
1335 func subjectBytes(cert *Certificate) ([]byte, error) {
1336 if len(cert.RawSubject) > 0 {
1337 return cert.RawSubject, nil
1340 return asn1.Marshal(cert.Subject.ToRDNSequence())
1343 // signingParamsForPublicKey returns the parameters to use for signing with
1344 // priv. If requestedSigAlgo is not zero then it overrides the default
1345 // signature algorithm.
1346 func signingParamsForPublicKey(pub any, requestedSigAlgo SignatureAlgorithm) (hashFunc crypto.Hash, sigAlgo pkix.AlgorithmIdentifier, err error) {
1347 var pubType PublicKeyAlgorithm
1349 switch pub := pub.(type) {
1350 case *rsa.PublicKey:
1352 hashFunc = crypto.SHA256
1353 sigAlgo.Algorithm = oidSignatureSHA256WithRSA
1354 sigAlgo.Parameters = asn1.NullRawValue
1356 case *ecdsa.PublicKey:
1360 case elliptic.P224(), elliptic.P256():
1361 hashFunc = crypto.SHA256
1362 sigAlgo.Algorithm = oidSignatureECDSAWithSHA256
1363 case elliptic.P384():
1364 hashFunc = crypto.SHA384
1365 sigAlgo.Algorithm = oidSignatureECDSAWithSHA384
1366 case elliptic.P521():
1367 hashFunc = crypto.SHA512
1368 sigAlgo.Algorithm = oidSignatureECDSAWithSHA512
1370 err = errors.New("x509: unknown elliptic curve")
1373 case ed25519.PublicKey:
1375 sigAlgo.Algorithm = oidSignatureEd25519
1378 err = errors.New("x509: only RSA, ECDSA and Ed25519 keys supported")
1385 if requestedSigAlgo == 0 {
1390 for _, details := range signatureAlgorithmDetails {
1391 if details.algo == requestedSigAlgo {
1392 if details.pubKeyAlgo != pubType {
1393 err = errors.New("x509: requested SignatureAlgorithm does not match private key type")
1396 sigAlgo.Algorithm, hashFunc = details.oid, details.hash
1397 if hashFunc == 0 && pubType != Ed25519 {
1398 err = errors.New("x509: cannot sign with hash function requested")
1401 if hashFunc == crypto.MD5 {
1402 err = errors.New("x509: signing with MD5 is not supported")
1405 if requestedSigAlgo.isRSAPSS() {
1406 sigAlgo.Parameters = hashToPSSParameters[hashFunc]
1414 err = errors.New("x509: unknown SignatureAlgorithm")
1420 // emptyASN1Subject is the ASN.1 DER encoding of an empty Subject, which is
1421 // just an empty SEQUENCE.
1422 var emptyASN1Subject = []byte{0x30, 0}
1424 // CreateCertificate creates a new X.509 v3 certificate based on a template.
1425 // The following members of template are currently used:
1428 // - BasicConstraintsValid
1429 // - CRLDistributionPoints
1432 // - ExcludedDNSDomains
1433 // - ExcludedEmailAddresses
1434 // - ExcludedIPRanges
1435 // - ExcludedURIDomains
1437 // - ExtraExtensions
1440 // - IssuingCertificateURL
1447 // - PermittedDNSDomains
1448 // - PermittedDNSDomainsCritical
1449 // - PermittedEmailAddresses
1450 // - PermittedIPRanges
1451 // - PermittedURIDomains
1452 // - PolicyIdentifiers
1454 // - SignatureAlgorithm
1458 // - UnknownExtKeyUsage
1460 // The certificate is signed by parent. If parent is equal to template then the
1461 // certificate is self-signed. The parameter pub is the public key of the
1462 // certificate to be generated and priv is the private key of the signer.
1464 // The returned slice is the certificate in DER encoding.
1466 // The currently supported key types are *rsa.PublicKey, *ecdsa.PublicKey and
1467 // ed25519.PublicKey. pub must be a supported key type, and priv must be a
1468 // crypto.Signer with a supported public key.
1470 // The AuthorityKeyId will be taken from the SubjectKeyId of parent, if any,
1471 // unless the resulting certificate is self-signed. Otherwise the value from
1472 // template will be used.
1474 // If SubjectKeyId from template is empty and the template is a CA, SubjectKeyId
1475 // will be generated from the hash of the public key.
1476 func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv any) ([]byte, error) {
1477 key, ok := priv.(crypto.Signer)
1479 return nil, errors.New("x509: certificate private key does not implement crypto.Signer")
1482 if template.SerialNumber == nil {
1483 return nil, errors.New("x509: no SerialNumber given")
1486 // RFC 5280 Section 4.1.2.2: serial number must positive
1488 // We _should_ also restrict serials to <= 20 octets, but it turns out a lot of people
1489 // get this wrong, in part because the encoding can itself alter the length of the
1490 // serial. For now we accept these non-conformant serials.
1491 if template.SerialNumber.Sign() == -1 {
1492 return nil, errors.New("x509: serial number must be positive")
1495 if template.BasicConstraintsValid && !template.IsCA && template.MaxPathLen != -1 && (template.MaxPathLen != 0 || template.MaxPathLenZero) {
1496 return nil, errors.New("x509: only CAs are allowed to specify MaxPathLen")
1499 hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(key.Public(), template.SignatureAlgorithm)
1504 publicKeyBytes, publicKeyAlgorithm, err := marshalPublicKey(pub)
1509 asn1Issuer, err := subjectBytes(parent)
1514 asn1Subject, err := subjectBytes(template)
1519 authorityKeyId := template.AuthorityKeyId
1520 if !bytes.Equal(asn1Issuer, asn1Subject) && len(parent.SubjectKeyId) > 0 {
1521 authorityKeyId = parent.SubjectKeyId
1524 subjectKeyId := template.SubjectKeyId
1525 if len(subjectKeyId) == 0 && template.IsCA {
1526 // SubjectKeyId generated using method 1 in RFC 5280, Section 4.2.1.2:
1527 // (1) The keyIdentifier is composed of the 160-bit SHA-1 hash of the
1528 // value of the BIT STRING subjectPublicKey (excluding the tag,
1529 // length, and number of unused bits).
1530 h := sha1.Sum(publicKeyBytes)
1534 // Check that the signer's public key matches the private key, if available.
1535 type privateKey interface {
1536 Equal(crypto.PublicKey) bool
1538 if privPub, ok := key.Public().(privateKey); !ok {
1539 return nil, errors.New("x509: internal error: supported public key does not implement Equal")
1540 } else if parent.PublicKey != nil && !privPub.Equal(parent.PublicKey) {
1541 return nil, errors.New("x509: provided PrivateKey doesn't match parent's PublicKey")
1544 extensions, err := buildCertExtensions(template, bytes.Equal(asn1Subject, emptyASN1Subject), authorityKeyId, subjectKeyId)
1549 encodedPublicKey := asn1.BitString{BitLength: len(publicKeyBytes) * 8, Bytes: publicKeyBytes}
1550 c := tbsCertificate{
1552 SerialNumber: template.SerialNumber,
1553 SignatureAlgorithm: signatureAlgorithm,
1554 Issuer: asn1.RawValue{FullBytes: asn1Issuer},
1555 Validity: validity{template.NotBefore.UTC(), template.NotAfter.UTC()},
1556 Subject: asn1.RawValue{FullBytes: asn1Subject},
1557 PublicKey: publicKeyInfo{nil, publicKeyAlgorithm, encodedPublicKey},
1558 Extensions: extensions,
1561 tbsCertContents, err := asn1.Marshal(c)
1565 c.Raw = tbsCertContents
1567 signed := tbsCertContents
1574 var signerOpts crypto.SignerOpts = hashFunc
1575 if template.SignatureAlgorithm != 0 && template.SignatureAlgorithm.isRSAPSS() {
1576 signerOpts = &rsa.PSSOptions{
1577 SaltLength: rsa.PSSSaltLengthEqualsHash,
1582 var signature []byte
1583 signature, err = key.Sign(rand, signed, signerOpts)
1588 signedCert, err := asn1.Marshal(certificate{
1592 asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
1598 // Check the signature to ensure the crypto.Signer behaved correctly.
1599 if err := checkSignature(getSignatureAlgorithmFromAI(signatureAlgorithm), c.Raw, signature, key.Public(), true); err != nil {
1600 return nil, fmt.Errorf("x509: signature over certificate returned by signer is invalid: %w", err)
1603 return signedCert, nil
1606 // pemCRLPrefix is the magic string that indicates that we have a PEM encoded
1608 var pemCRLPrefix = []byte("-----BEGIN X509 CRL")
1610 // pemType is the type of a PEM encoded CRL.
1611 var pemType = "X509 CRL"
1613 // ParseCRL parses a CRL from the given bytes. It's often the case that PEM
1614 // encoded CRLs will appear where they should be DER encoded, so this function
1615 // will transparently handle PEM encoding as long as there isn't any leading
1618 // Deprecated: Use ParseRevocationList instead.
1619 func ParseCRL(crlBytes []byte) (*pkix.CertificateList, error) {
1620 if bytes.HasPrefix(crlBytes, pemCRLPrefix) {
1621 block, _ := pem.Decode(crlBytes)
1622 if block != nil && block.Type == pemType {
1623 crlBytes = block.Bytes
1626 return ParseDERCRL(crlBytes)
1629 // ParseDERCRL parses a DER encoded CRL from the given bytes.
1631 // Deprecated: Use ParseRevocationList instead.
1632 func ParseDERCRL(derBytes []byte) (*pkix.CertificateList, error) {
1633 certList := new(pkix.CertificateList)
1634 if rest, err := asn1.Unmarshal(derBytes, certList); err != nil {
1636 } else if len(rest) != 0 {
1637 return nil, errors.New("x509: trailing data after CRL")
1639 return certList, nil
1642 // CreateCRL returns a DER encoded CRL, signed by this Certificate, that
1643 // contains the given list of revoked certificates.
1645 // Deprecated: this method does not generate an RFC 5280 conformant X.509 v2 CRL.
1646 // To generate a standards compliant CRL, use CreateRevocationList instead.
1647 func (c *Certificate) CreateCRL(rand io.Reader, priv any, revokedCerts []pkix.RevokedCertificate, now, expiry time.Time) (crlBytes []byte, err error) {
1648 key, ok := priv.(crypto.Signer)
1650 return nil, errors.New("x509: certificate private key does not implement crypto.Signer")
1653 hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(key.Public(), 0)
1658 // Force revocation times to UTC per RFC 5280.
1659 revokedCertsUTC := make([]pkix.RevokedCertificate, len(revokedCerts))
1660 for i, rc := range revokedCerts {
1661 rc.RevocationTime = rc.RevocationTime.UTC()
1662 revokedCertsUTC[i] = rc
1665 tbsCertList := pkix.TBSCertificateList{
1667 Signature: signatureAlgorithm,
1668 Issuer: c.Subject.ToRDNSequence(),
1669 ThisUpdate: now.UTC(),
1670 NextUpdate: expiry.UTC(),
1671 RevokedCertificates: revokedCertsUTC,
1675 if len(c.SubjectKeyId) > 0 {
1676 var aki pkix.Extension
1677 aki.Id = oidExtensionAuthorityKeyId
1678 aki.Value, err = asn1.Marshal(authKeyId{Id: c.SubjectKeyId})
1682 tbsCertList.Extensions = append(tbsCertList.Extensions, aki)
1685 tbsCertListContents, err := asn1.Marshal(tbsCertList)
1690 signed := tbsCertListContents
1697 var signature []byte
1698 signature, err = key.Sign(rand, signed, hashFunc)
1703 return asn1.Marshal(pkix.CertificateList{
1704 TBSCertList: tbsCertList,
1705 SignatureAlgorithm: signatureAlgorithm,
1706 SignatureValue: asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
1710 // CertificateRequest represents a PKCS #10, certificate signature request.
1711 type CertificateRequest struct {
1712 Raw []byte // Complete ASN.1 DER content (CSR, signature algorithm and signature).
1713 RawTBSCertificateRequest []byte // Certificate request info part of raw ASN.1 DER content.
1714 RawSubjectPublicKeyInfo []byte // DER encoded SubjectPublicKeyInfo.
1715 RawSubject []byte // DER encoded Subject.
1719 SignatureAlgorithm SignatureAlgorithm
1721 PublicKeyAlgorithm PublicKeyAlgorithm
1726 // Attributes contains the CSR attributes that can parse as
1727 // pkix.AttributeTypeAndValueSET.
1729 // Deprecated: Use Extensions and ExtraExtensions instead for parsing and
1730 // generating the requestedExtensions attribute.
1731 Attributes []pkix.AttributeTypeAndValueSET
1733 // Extensions contains all requested extensions, in raw form. When parsing
1734 // CSRs, this can be used to extract extensions that are not parsed by this
1736 Extensions []pkix.Extension
1738 // ExtraExtensions contains extensions to be copied, raw, into any CSR
1739 // marshaled by CreateCertificateRequest. Values override any extensions
1740 // that would otherwise be produced based on the other fields but are
1741 // overridden by any extensions specified in Attributes.
1743 // The ExtraExtensions field is not populated by ParseCertificateRequest,
1744 // see Extensions instead.
1745 ExtraExtensions []pkix.Extension
1747 // Subject Alternate Name values.
1749 EmailAddresses []string
1750 IPAddresses []net.IP
1754 // These structures reflect the ASN.1 structure of X.509 certificate
1755 // signature requests (see RFC 2986):
1757 type tbsCertificateRequest struct {
1760 Subject asn1.RawValue
1761 PublicKey publicKeyInfo
1762 RawAttributes []asn1.RawValue `asn1:"tag:0"`
1765 type certificateRequest struct {
1767 TBSCSR tbsCertificateRequest
1768 SignatureAlgorithm pkix.AlgorithmIdentifier
1769 SignatureValue asn1.BitString
1772 // oidExtensionRequest is a PKCS #9 OBJECT IDENTIFIER that indicates requested
1773 // extensions in a CSR.
1774 var oidExtensionRequest = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 9, 14}
1776 // newRawAttributes converts AttributeTypeAndValueSETs from a template
1777 // CertificateRequest's Attributes into tbsCertificateRequest RawAttributes.
1778 func newRawAttributes(attributes []pkix.AttributeTypeAndValueSET) ([]asn1.RawValue, error) {
1779 var rawAttributes []asn1.RawValue
1780 b, err := asn1.Marshal(attributes)
1784 rest, err := asn1.Unmarshal(b, &rawAttributes)
1789 return nil, errors.New("x509: failed to unmarshal raw CSR Attributes")
1791 return rawAttributes, nil
1794 // parseRawAttributes Unmarshals RawAttributes into AttributeTypeAndValueSETs.
1795 func parseRawAttributes(rawAttributes []asn1.RawValue) []pkix.AttributeTypeAndValueSET {
1796 var attributes []pkix.AttributeTypeAndValueSET
1797 for _, rawAttr := range rawAttributes {
1798 var attr pkix.AttributeTypeAndValueSET
1799 rest, err := asn1.Unmarshal(rawAttr.FullBytes, &attr)
1800 // Ignore attributes that don't parse into pkix.AttributeTypeAndValueSET
1801 // (i.e.: challengePassword or unstructuredName).
1802 if err == nil && len(rest) == 0 {
1803 attributes = append(attributes, attr)
1809 // parseCSRExtensions parses the attributes from a CSR and extracts any
1810 // requested extensions.
1811 func parseCSRExtensions(rawAttributes []asn1.RawValue) ([]pkix.Extension, error) {
1812 // pkcs10Attribute reflects the Attribute structure from RFC 2986, Section 4.1.
1813 type pkcs10Attribute struct {
1814 Id asn1.ObjectIdentifier
1815 Values []asn1.RawValue `asn1:"set"`
1818 var ret []pkix.Extension
1819 seenExts := make(map[string]bool)
1820 for _, rawAttr := range rawAttributes {
1821 var attr pkcs10Attribute
1822 if rest, err := asn1.Unmarshal(rawAttr.FullBytes, &attr); err != nil || len(rest) != 0 || len(attr.Values) == 0 {
1823 // Ignore attributes that don't parse.
1826 oidStr := attr.Id.String()
1827 if seenExts[oidStr] {
1828 return nil, errors.New("x509: certificate request contains duplicate extensions")
1830 seenExts[oidStr] = true
1832 if !attr.Id.Equal(oidExtensionRequest) {
1836 var extensions []pkix.Extension
1837 if _, err := asn1.Unmarshal(attr.Values[0].FullBytes, &extensions); err != nil {
1840 requestedExts := make(map[string]bool)
1841 for _, ext := range extensions {
1842 oidStr := ext.Id.String()
1843 if requestedExts[oidStr] {
1844 return nil, errors.New("x509: certificate request contains duplicate requested extensions")
1846 requestedExts[oidStr] = true
1848 ret = append(ret, extensions...)
1854 // CreateCertificateRequest creates a new certificate request based on a
1855 // template. The following members of template are used:
1857 // - SignatureAlgorithm
1863 // - ExtraExtensions
1864 // - Attributes (deprecated)
1866 // priv is the private key to sign the CSR with, and the corresponding public
1867 // key will be included in the CSR. It must implement crypto.Signer and its
1868 // Public() method must return a *rsa.PublicKey or a *ecdsa.PublicKey or a
1869 // ed25519.PublicKey. (A *rsa.PrivateKey, *ecdsa.PrivateKey or
1870 // ed25519.PrivateKey satisfies this.)
1872 // The returned slice is the certificate request in DER encoding.
1873 func CreateCertificateRequest(rand io.Reader, template *CertificateRequest, priv any) (csr []byte, err error) {
1874 key, ok := priv.(crypto.Signer)
1876 return nil, errors.New("x509: certificate private key does not implement crypto.Signer")
1879 var hashFunc crypto.Hash
1880 var sigAlgo pkix.AlgorithmIdentifier
1881 hashFunc, sigAlgo, err = signingParamsForPublicKey(key.Public(), template.SignatureAlgorithm)
1886 var publicKeyBytes []byte
1887 var publicKeyAlgorithm pkix.AlgorithmIdentifier
1888 publicKeyBytes, publicKeyAlgorithm, err = marshalPublicKey(key.Public())
1893 extensions, err := buildCSRExtensions(template)
1898 // Make a copy of template.Attributes because we may alter it below.
1899 attributes := make([]pkix.AttributeTypeAndValueSET, 0, len(template.Attributes))
1900 for _, attr := range template.Attributes {
1901 values := make([][]pkix.AttributeTypeAndValue, len(attr.Value))
1902 copy(values, attr.Value)
1903 attributes = append(attributes, pkix.AttributeTypeAndValueSET{
1909 extensionsAppended := false
1910 if len(extensions) > 0 {
1911 // Append the extensions to an existing attribute if possible.
1912 for _, atvSet := range attributes {
1913 if !atvSet.Type.Equal(oidExtensionRequest) || len(atvSet.Value) == 0 {
1917 // specifiedExtensions contains all the extensions that we
1918 // found specified via template.Attributes.
1919 specifiedExtensions := make(map[string]bool)
1921 for _, atvs := range atvSet.Value {
1922 for _, atv := range atvs {
1923 specifiedExtensions[atv.Type.String()] = true
1927 newValue := make([]pkix.AttributeTypeAndValue, 0, len(atvSet.Value[0])+len(extensions))
1928 newValue = append(newValue, atvSet.Value[0]...)
1930 for _, e := range extensions {
1931 if specifiedExtensions[e.Id.String()] {
1932 // Attributes already contained a value for
1933 // this extension and it takes priority.
1937 newValue = append(newValue, pkix.AttributeTypeAndValue{
1938 // There is no place for the critical
1939 // flag in an AttributeTypeAndValue.
1945 atvSet.Value[0] = newValue
1946 extensionsAppended = true
1951 rawAttributes, err := newRawAttributes(attributes)
1956 // If not included in attributes, add a new attribute for the
1958 if len(extensions) > 0 && !extensionsAppended {
1960 Type asn1.ObjectIdentifier
1961 Value [][]pkix.Extension `asn1:"set"`
1963 Type: oidExtensionRequest,
1964 Value: [][]pkix.Extension{extensions},
1967 b, err := asn1.Marshal(attr)
1969 return nil, errors.New("x509: failed to serialise extensions attribute: " + err.Error())
1972 var rawValue asn1.RawValue
1973 if _, err := asn1.Unmarshal(b, &rawValue); err != nil {
1977 rawAttributes = append(rawAttributes, rawValue)
1980 asn1Subject := template.RawSubject
1981 if len(asn1Subject) == 0 {
1982 asn1Subject, err = asn1.Marshal(template.Subject.ToRDNSequence())
1988 tbsCSR := tbsCertificateRequest{
1989 Version: 0, // PKCS #10, RFC 2986
1990 Subject: asn1.RawValue{FullBytes: asn1Subject},
1991 PublicKey: publicKeyInfo{
1992 Algorithm: publicKeyAlgorithm,
1993 PublicKey: asn1.BitString{
1994 Bytes: publicKeyBytes,
1995 BitLength: len(publicKeyBytes) * 8,
1998 RawAttributes: rawAttributes,
2001 tbsCSRContents, err := asn1.Marshal(tbsCSR)
2005 tbsCSR.Raw = tbsCSRContents
2007 signed := tbsCSRContents
2014 var signature []byte
2015 signature, err = key.Sign(rand, signed, hashFunc)
2020 return asn1.Marshal(certificateRequest{
2022 SignatureAlgorithm: sigAlgo,
2023 SignatureValue: asn1.BitString{
2025 BitLength: len(signature) * 8,
2030 // ParseCertificateRequest parses a single certificate request from the
2031 // given ASN.1 DER data.
2032 func ParseCertificateRequest(asn1Data []byte) (*CertificateRequest, error) {
2033 var csr certificateRequest
2035 rest, err := asn1.Unmarshal(asn1Data, &csr)
2038 } else if len(rest) != 0 {
2039 return nil, asn1.SyntaxError{Msg: "trailing data"}
2042 return parseCertificateRequest(&csr)
2045 func parseCertificateRequest(in *certificateRequest) (*CertificateRequest, error) {
2046 out := &CertificateRequest{
2048 RawTBSCertificateRequest: in.TBSCSR.Raw,
2049 RawSubjectPublicKeyInfo: in.TBSCSR.PublicKey.Raw,
2050 RawSubject: in.TBSCSR.Subject.FullBytes,
2052 Signature: in.SignatureValue.RightAlign(),
2053 SignatureAlgorithm: getSignatureAlgorithmFromAI(in.SignatureAlgorithm),
2055 PublicKeyAlgorithm: getPublicKeyAlgorithmFromOID(in.TBSCSR.PublicKey.Algorithm.Algorithm),
2057 Version: in.TBSCSR.Version,
2058 Attributes: parseRawAttributes(in.TBSCSR.RawAttributes),
2062 out.PublicKey, err = parsePublicKey(out.PublicKeyAlgorithm, &in.TBSCSR.PublicKey)
2067 var subject pkix.RDNSequence
2068 if rest, err := asn1.Unmarshal(in.TBSCSR.Subject.FullBytes, &subject); err != nil {
2070 } else if len(rest) != 0 {
2071 return nil, errors.New("x509: trailing data after X.509 Subject")
2074 out.Subject.FillFromRDNSequence(&subject)
2076 if out.Extensions, err = parseCSRExtensions(in.TBSCSR.RawAttributes); err != nil {
2080 for _, extension := range out.Extensions {
2082 case extension.Id.Equal(oidExtensionSubjectAltName):
2083 out.DNSNames, out.EmailAddresses, out.IPAddresses, out.URIs, err = parseSANExtension(extension.Value)
2093 // CheckSignature reports whether the signature on c is valid.
2094 func (c *CertificateRequest) CheckSignature() error {
2095 return checkSignature(c.SignatureAlgorithm, c.RawTBSCertificateRequest, c.Signature, c.PublicKey, true)
2098 // RevocationList contains the fields used to create an X.509 v2 Certificate
2099 // Revocation list with CreateRevocationList.
2100 type RevocationList struct {
2101 // Raw contains the complete ASN.1 DER content of the CRL (tbsCertList,
2102 // signatureAlgorithm, and signatureValue.)
2104 // RawTBSRevocationList contains just the tbsCertList portion of the ASN.1
2106 RawTBSRevocationList []byte
2107 // RawIssuer contains the DER encoded Issuer.
2110 // Issuer contains the DN of the issuing certificate.
2112 // AuthorityKeyId is used to identify the public key associated with the
2113 // issuing certificate. It is populated from the authorityKeyIdentifier
2114 // extension when parsing a CRL. It is ignored when creating a CRL; the
2115 // extension is populated from the issuing certificate itself.
2116 AuthorityKeyId []byte
2119 // SignatureAlgorithm is used to determine the signature algorithm to be
2120 // used when signing the CRL. If 0 the default algorithm for the signing
2121 // key will be used.
2122 SignatureAlgorithm SignatureAlgorithm
2124 // RevokedCertificates is used to populate the revokedCertificates
2125 // sequence in the CRL, it may be empty. RevokedCertificates may be nil,
2126 // in which case an empty CRL will be created.
2127 RevokedCertificates []pkix.RevokedCertificate
2129 // Number is used to populate the X.509 v2 cRLNumber extension in the CRL,
2130 // which should be a monotonically increasing sequence number for a given
2131 // CRL scope and CRL issuer. It is also populated from the cRLNumber
2132 // extension when parsing a CRL.
2135 // ThisUpdate is used to populate the thisUpdate field in the CRL, which
2136 // indicates the issuance date of the CRL.
2137 ThisUpdate time.Time
2138 // NextUpdate is used to populate the nextUpdate field in the CRL, which
2139 // indicates the date by which the next CRL will be issued. NextUpdate
2140 // must be greater than ThisUpdate.
2141 NextUpdate time.Time
2143 // Extensions contains raw X.509 extensions. When creating a CRL,
2144 // the Extensions field is ignored, see ExtraExtensions.
2145 Extensions []pkix.Extension
2147 // ExtraExtensions contains any additional extensions to add directly to
2149 ExtraExtensions []pkix.Extension
2152 // These structures reflect the ASN.1 structure of X.509 CRLs better than
2153 // the existing crypto/x509/pkix variants do. These mirror the existing
2154 // certificate structs in this file.
2156 // Notably, we include issuer as an asn1.RawValue, mirroring the behavior of
2157 // tbsCertificate and allowing raw (unparsed) subjects to be passed cleanly.
2158 type certificateList struct {
2159 TBSCertList tbsCertificateList
2160 SignatureAlgorithm pkix.AlgorithmIdentifier
2161 SignatureValue asn1.BitString
2164 type tbsCertificateList struct {
2166 Version int `asn1:"optional,default:0"`
2167 Signature pkix.AlgorithmIdentifier
2168 Issuer asn1.RawValue
2169 ThisUpdate time.Time
2170 NextUpdate time.Time `asn1:"optional"`
2171 RevokedCertificates []pkix.RevokedCertificate `asn1:"optional"`
2172 Extensions []pkix.Extension `asn1:"tag:0,optional,explicit"`
2175 // CreateRevocationList creates a new X.509 v2 Certificate Revocation List,
2176 // according to RFC 5280, based on template.
2178 // The CRL is signed by priv which should be the private key associated with
2179 // the public key in the issuer certificate.
2181 // The issuer may not be nil, and the crlSign bit must be set in KeyUsage in
2182 // order to use it as a CRL issuer.
2184 // The issuer distinguished name CRL field and authority key identifier
2185 // extension are populated using the issuer certificate. issuer must have
2186 // SubjectKeyId set.
2187 func CreateRevocationList(rand io.Reader, template *RevocationList, issuer *Certificate, priv crypto.Signer) ([]byte, error) {
2188 if template == nil {
2189 return nil, errors.New("x509: template can not be nil")
2192 return nil, errors.New("x509: issuer can not be nil")
2194 if (issuer.KeyUsage & KeyUsageCRLSign) == 0 {
2195 return nil, errors.New("x509: issuer must have the crlSign key usage bit set")
2197 if len(issuer.SubjectKeyId) == 0 {
2198 return nil, errors.New("x509: issuer certificate doesn't contain a subject key identifier")
2200 if template.NextUpdate.Before(template.ThisUpdate) {
2201 return nil, errors.New("x509: template.ThisUpdate is after template.NextUpdate")
2203 if template.Number == nil {
2204 return nil, errors.New("x509: template contains nil Number field")
2207 hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(priv.Public(), template.SignatureAlgorithm)
2212 // Force revocation times to UTC per RFC 5280.
2213 revokedCertsUTC := make([]pkix.RevokedCertificate, len(template.RevokedCertificates))
2214 for i, rc := range template.RevokedCertificates {
2215 rc.RevocationTime = rc.RevocationTime.UTC()
2216 revokedCertsUTC[i] = rc
2219 aki, err := asn1.Marshal(authKeyId{Id: issuer.SubjectKeyId})
2224 if numBytes := template.Number.Bytes(); len(numBytes) > 20 || (len(numBytes) == 20 && numBytes[0]&0x80 != 0) {
2225 return nil, errors.New("x509: CRL number exceeds 20 octets")
2227 crlNum, err := asn1.Marshal(template.Number)
2232 // Correctly use the issuer's subject sequence if one is specified.
2233 issuerSubject, err := subjectBytes(issuer)
2238 tbsCertList := tbsCertificateList{
2240 Signature: signatureAlgorithm,
2241 Issuer: asn1.RawValue{FullBytes: issuerSubject},
2242 ThisUpdate: template.ThisUpdate.UTC(),
2243 NextUpdate: template.NextUpdate.UTC(),
2244 Extensions: []pkix.Extension{
2246 Id: oidExtensionAuthorityKeyId,
2250 Id: oidExtensionCRLNumber,
2255 if len(revokedCertsUTC) > 0 {
2256 tbsCertList.RevokedCertificates = revokedCertsUTC
2259 if len(template.ExtraExtensions) > 0 {
2260 tbsCertList.Extensions = append(tbsCertList.Extensions, template.ExtraExtensions...)
2263 tbsCertListContents, err := asn1.Marshal(tbsCertList)
2268 // Optimization to only marshal this struct once, when signing and
2269 // then embedding in certificateList below.
2270 tbsCertList.Raw = tbsCertListContents
2272 input := tbsCertListContents
2275 h.Write(tbsCertListContents)
2278 var signerOpts crypto.SignerOpts = hashFunc
2279 if template.SignatureAlgorithm.isRSAPSS() {
2280 signerOpts = &rsa.PSSOptions{
2281 SaltLength: rsa.PSSSaltLengthEqualsHash,
2286 signature, err := priv.Sign(rand, input, signerOpts)
2291 return asn1.Marshal(certificateList{
2292 TBSCertList: tbsCertList,
2293 SignatureAlgorithm: signatureAlgorithm,
2294 SignatureValue: asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
2298 // CheckSignatureFrom verifies that the signature on rl is a valid signature
2300 func (rl *RevocationList) CheckSignatureFrom(parent *Certificate) error {
2301 if parent.Version == 3 && !parent.BasicConstraintsValid ||
2302 parent.BasicConstraintsValid && !parent.IsCA {
2303 return ConstraintViolationError{}
2306 if parent.KeyUsage != 0 && parent.KeyUsage&KeyUsageCRLSign == 0 {
2307 return ConstraintViolationError{}
2310 if parent.PublicKeyAlgorithm == UnknownPublicKeyAlgorithm {
2311 return ErrUnsupportedAlgorithm
2314 return parent.CheckSignature(rl.SignatureAlgorithm, rl.RawTBSRevocationList, rl.Signature)