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 implements a subset of the X.509 standard.
7 // It allows parsing and generating certificates, certificate signing
8 // requests, certificate revocation lists, and encoded public and private keys.
9 // It provides a certificate verifier, complete with a chain builder.
11 // The package targets the X.509 technical profile defined by the IETF (RFC
12 // 2459/3280/5280), and as further restricted by the CA/Browser Forum Baseline
13 // Requirements. There is minimal support for features outside of these
14 // profiles, as the primary goal of the package is to provide compatibility
15 // with the publicly trusted TLS certificate ecosystem and its policies and
18 // On macOS and Windows, certificate verification is handled by system APIs, but
19 // the package aims to apply consistent validation rules across operating
46 // Explicitly import these for their crypto.RegisterHash init side-effects.
47 // Keep these as blank imports, even if they're imported above.
52 "golang.org/x/crypto/cryptobyte"
53 cryptobyte_asn1 "golang.org/x/crypto/cryptobyte/asn1"
56 // pkixPublicKey reflects a PKIX public key structure. See SubjectPublicKeyInfo
58 type pkixPublicKey struct {
59 Algo pkix.AlgorithmIdentifier
60 BitString asn1.BitString
63 // ParsePKIXPublicKey parses a public key in PKIX, ASN.1 DER form. The encoded
64 // public key is a SubjectPublicKeyInfo structure (see RFC 5280, Section 4.1).
66 // It returns a *rsa.PublicKey, *dsa.PublicKey, *ecdsa.PublicKey,
67 // ed25519.PublicKey (not a pointer), or *ecdh.PublicKey (for X25519).
68 // More types might be supported in the future.
70 // This kind of key is commonly encoded in PEM blocks of type "PUBLIC KEY".
71 func ParsePKIXPublicKey(derBytes []byte) (pub any, err error) {
73 if rest, err := asn1.Unmarshal(derBytes, &pki); err != nil {
74 if _, err := asn1.Unmarshal(derBytes, &pkcs1PublicKey{}); err == nil {
75 return nil, errors.New("x509: failed to parse public key (use ParsePKCS1PublicKey instead for this key format)")
78 } else if len(rest) != 0 {
79 return nil, errors.New("x509: trailing data after ASN.1 of public-key")
81 return parsePublicKey(&pki)
84 func marshalPublicKey(pub any) (publicKeyBytes []byte, publicKeyAlgorithm pkix.AlgorithmIdentifier, err error) {
85 switch pub := pub.(type) {
87 publicKeyBytes, err = asn1.Marshal(pkcs1PublicKey{
92 return nil, pkix.AlgorithmIdentifier{}, err
94 publicKeyAlgorithm.Algorithm = oidPublicKeyRSA
95 // This is a NULL parameters value which is required by
96 // RFC 3279, Section 2.3.1.
97 publicKeyAlgorithm.Parameters = asn1.NullRawValue
98 case *ecdsa.PublicKey:
99 oid, ok := oidFromNamedCurve(pub.Curve)
101 return nil, pkix.AlgorithmIdentifier{}, errors.New("x509: unsupported elliptic curve")
103 if !pub.Curve.IsOnCurve(pub.X, pub.Y) {
104 return nil, pkix.AlgorithmIdentifier{}, errors.New("x509: invalid elliptic curve public key")
106 publicKeyBytes = elliptic.Marshal(pub.Curve, pub.X, pub.Y)
107 publicKeyAlgorithm.Algorithm = oidPublicKeyECDSA
108 var paramBytes []byte
109 paramBytes, err = asn1.Marshal(oid)
113 publicKeyAlgorithm.Parameters.FullBytes = paramBytes
114 case ed25519.PublicKey:
116 publicKeyAlgorithm.Algorithm = oidPublicKeyEd25519
117 case *ecdh.PublicKey:
118 if pub.Curve() != ecdh.X25519() {
119 return nil, pkix.AlgorithmIdentifier{}, errors.New("x509: unsupported ECDH curve")
121 publicKeyBytes = pub.Bytes()
122 publicKeyAlgorithm.Algorithm = oidPublicKeyX25519
124 return nil, pkix.AlgorithmIdentifier{}, fmt.Errorf("x509: unsupported public key type: %T", pub)
127 return publicKeyBytes, publicKeyAlgorithm, nil
130 // MarshalPKIXPublicKey converts a public key to PKIX, ASN.1 DER form.
131 // The encoded public key is a SubjectPublicKeyInfo structure
132 // (see RFC 5280, Section 4.1).
134 // The following key types are currently supported: *rsa.PublicKey,
135 // *ecdsa.PublicKey, ed25519.PublicKey (not a pointer), and *ecdh.PublicKey
136 // (X25519 only). Unsupported key types result in an error.
138 // This kind of key is commonly encoded in PEM blocks of type "PUBLIC KEY".
139 func MarshalPKIXPublicKey(pub any) ([]byte, error) {
140 var publicKeyBytes []byte
141 var publicKeyAlgorithm pkix.AlgorithmIdentifier
144 if publicKeyBytes, publicKeyAlgorithm, err = marshalPublicKey(pub); err != nil {
148 pkix := pkixPublicKey{
149 Algo: publicKeyAlgorithm,
150 BitString: asn1.BitString{
151 Bytes: publicKeyBytes,
152 BitLength: 8 * len(publicKeyBytes),
156 ret, _ := asn1.Marshal(pkix)
160 // These structures reflect the ASN.1 structure of X.509 certificates.:
162 type certificate struct {
163 TBSCertificate tbsCertificate
164 SignatureAlgorithm pkix.AlgorithmIdentifier
165 SignatureValue asn1.BitString
168 type tbsCertificate struct {
170 Version int `asn1:"optional,explicit,default:0,tag:0"`
171 SerialNumber *big.Int
172 SignatureAlgorithm pkix.AlgorithmIdentifier
175 Subject asn1.RawValue
176 PublicKey publicKeyInfo
177 UniqueId asn1.BitString `asn1:"optional,tag:1"`
178 SubjectUniqueId asn1.BitString `asn1:"optional,tag:2"`
179 Extensions []pkix.Extension `asn1:"omitempty,optional,explicit,tag:3"`
182 type dsaAlgorithmParameters struct {
186 type validity struct {
187 NotBefore, NotAfter time.Time
190 type publicKeyInfo struct {
192 Algorithm pkix.AlgorithmIdentifier
193 PublicKey asn1.BitString
197 type authKeyId struct {
198 Id []byte `asn1:"optional,tag:0"`
201 type SignatureAlgorithm int
204 UnknownSignatureAlgorithm SignatureAlgorithm = iota
206 MD2WithRSA // Unsupported.
207 MD5WithRSA // Only supported for signing, not verification.
208 SHA1WithRSA // Only supported for signing, and verification of CRLs, CSRs, and OCSP responses.
212 DSAWithSHA1 // Unsupported.
213 DSAWithSHA256 // Unsupported.
214 ECDSAWithSHA1 // Only supported for signing, and verification of CRLs, CSRs, and OCSP responses.
224 func (algo SignatureAlgorithm) isRSAPSS() bool {
226 case SHA256WithRSAPSS, SHA384WithRSAPSS, SHA512WithRSAPSS:
233 func (algo SignatureAlgorithm) String() string {
234 for _, details := range signatureAlgorithmDetails {
235 if details.algo == algo {
239 return strconv.Itoa(int(algo))
242 type PublicKeyAlgorithm int
245 UnknownPublicKeyAlgorithm PublicKeyAlgorithm = iota
247 DSA // Only supported for parsing.
252 var publicKeyAlgoName = [...]string{
259 func (algo PublicKeyAlgorithm) String() string {
260 if 0 < algo && int(algo) < len(publicKeyAlgoName) {
261 return publicKeyAlgoName[algo]
263 return strconv.Itoa(int(algo))
266 // OIDs for signature algorithms
268 // pkcs-1 OBJECT IDENTIFIER ::= {
269 // iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 1 }
271 // RFC 3279 2.2.1 RSA Signature Algorithms
273 // md2WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 2 }
275 // md5WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 4 }
277 // sha-1WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 5 }
279 // dsaWithSha1 OBJECT IDENTIFIER ::= {
280 // iso(1) member-body(2) us(840) x9-57(10040) x9cm(4) 3 }
282 // RFC 3279 2.2.3 ECDSA Signature Algorithm
284 // ecdsa-with-SHA1 OBJECT IDENTIFIER ::= {
285 // iso(1) member-body(2) us(840) ansi-x962(10045)
286 // signatures(4) ecdsa-with-SHA1(1)}
288 // RFC 4055 5 PKCS #1 Version 1.5
290 // sha256WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 11 }
292 // sha384WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 12 }
294 // sha512WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 13 }
296 // RFC 5758 3.1 DSA Signature Algorithms
298 // dsaWithSha256 OBJECT IDENTIFIER ::= {
299 // joint-iso-ccitt(2) country(16) us(840) organization(1) gov(101)
300 // csor(3) algorithms(4) id-dsa-with-sha2(3) 2}
302 // RFC 5758 3.2 ECDSA Signature Algorithm
304 // ecdsa-with-SHA256 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
305 // us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 2 }
307 // ecdsa-with-SHA384 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
308 // us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 3 }
310 // ecdsa-with-SHA512 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
311 // us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 4 }
313 // RFC 8410 3 Curve25519 and Curve448 Algorithm Identifiers
315 // id-Ed25519 OBJECT IDENTIFIER ::= { 1 3 101 112 }
317 oidSignatureMD2WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 2}
318 oidSignatureMD5WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 4}
319 oidSignatureSHA1WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 5}
320 oidSignatureSHA256WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 11}
321 oidSignatureSHA384WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 12}
322 oidSignatureSHA512WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 13}
323 oidSignatureRSAPSS = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 10}
324 oidSignatureDSAWithSHA1 = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 3}
325 oidSignatureDSAWithSHA256 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 3, 2}
326 oidSignatureECDSAWithSHA1 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 1}
327 oidSignatureECDSAWithSHA256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 2}
328 oidSignatureECDSAWithSHA384 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 3}
329 oidSignatureECDSAWithSHA512 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 4}
330 oidSignatureEd25519 = asn1.ObjectIdentifier{1, 3, 101, 112}
332 oidSHA256 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 1}
333 oidSHA384 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 2}
334 oidSHA512 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 2, 3}
336 oidMGF1 = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 8}
338 // oidISOSignatureSHA1WithRSA means the same as oidSignatureSHA1WithRSA
339 // but it's specified by ISO. Microsoft's makecert.exe has been known
340 // to produce certificates with this OID.
341 oidISOSignatureSHA1WithRSA = asn1.ObjectIdentifier{1, 3, 14, 3, 2, 29}
344 var signatureAlgorithmDetails = []struct {
345 algo SignatureAlgorithm
347 oid asn1.ObjectIdentifier
348 pubKeyAlgo PublicKeyAlgorithm
351 {MD2WithRSA, "MD2-RSA", oidSignatureMD2WithRSA, RSA, crypto.Hash(0) /* no value for MD2 */},
352 {MD5WithRSA, "MD5-RSA", oidSignatureMD5WithRSA, RSA, crypto.MD5},
353 {SHA1WithRSA, "SHA1-RSA", oidSignatureSHA1WithRSA, RSA, crypto.SHA1},
354 {SHA1WithRSA, "SHA1-RSA", oidISOSignatureSHA1WithRSA, RSA, crypto.SHA1},
355 {SHA256WithRSA, "SHA256-RSA", oidSignatureSHA256WithRSA, RSA, crypto.SHA256},
356 {SHA384WithRSA, "SHA384-RSA", oidSignatureSHA384WithRSA, RSA, crypto.SHA384},
357 {SHA512WithRSA, "SHA512-RSA", oidSignatureSHA512WithRSA, RSA, crypto.SHA512},
358 {SHA256WithRSAPSS, "SHA256-RSAPSS", oidSignatureRSAPSS, RSA, crypto.SHA256},
359 {SHA384WithRSAPSS, "SHA384-RSAPSS", oidSignatureRSAPSS, RSA, crypto.SHA384},
360 {SHA512WithRSAPSS, "SHA512-RSAPSS", oidSignatureRSAPSS, RSA, crypto.SHA512},
361 {DSAWithSHA1, "DSA-SHA1", oidSignatureDSAWithSHA1, DSA, crypto.SHA1},
362 {DSAWithSHA256, "DSA-SHA256", oidSignatureDSAWithSHA256, DSA, crypto.SHA256},
363 {ECDSAWithSHA1, "ECDSA-SHA1", oidSignatureECDSAWithSHA1, ECDSA, crypto.SHA1},
364 {ECDSAWithSHA256, "ECDSA-SHA256", oidSignatureECDSAWithSHA256, ECDSA, crypto.SHA256},
365 {ECDSAWithSHA384, "ECDSA-SHA384", oidSignatureECDSAWithSHA384, ECDSA, crypto.SHA384},
366 {ECDSAWithSHA512, "ECDSA-SHA512", oidSignatureECDSAWithSHA512, ECDSA, crypto.SHA512},
367 {PureEd25519, "Ed25519", oidSignatureEd25519, Ed25519, crypto.Hash(0) /* no pre-hashing */},
370 // hashToPSSParameters contains the DER encoded RSA PSS parameters for the
371 // SHA256, SHA384, and SHA512 hashes as defined in RFC 3447, Appendix A.2.3.
372 // The parameters contain the following values:
373 // - hashAlgorithm contains the associated hash identifier with NULL parameters
374 // - maskGenAlgorithm always contains the default mgf1SHA1 identifier
375 // - saltLength contains the length of the associated hash
376 // - trailerField always contains the default trailerFieldBC value
377 var hashToPSSParameters = map[crypto.Hash]asn1.RawValue{
378 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}},
379 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}},
380 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}},
383 // pssParameters reflects the parameters in an AlgorithmIdentifier that
384 // specifies RSA PSS. See RFC 3447, Appendix A.2.3.
385 type pssParameters struct {
386 // The following three fields are not marked as
387 // optional because the default values specify SHA-1,
388 // which is no longer suitable for use in signatures.
389 Hash pkix.AlgorithmIdentifier `asn1:"explicit,tag:0"`
390 MGF pkix.AlgorithmIdentifier `asn1:"explicit,tag:1"`
391 SaltLength int `asn1:"explicit,tag:2"`
392 TrailerField int `asn1:"optional,explicit,tag:3,default:1"`
395 func getSignatureAlgorithmFromAI(ai pkix.AlgorithmIdentifier) SignatureAlgorithm {
396 if ai.Algorithm.Equal(oidSignatureEd25519) {
397 // RFC 8410, Section 3
398 // > For all of the OIDs, the parameters MUST be absent.
399 if len(ai.Parameters.FullBytes) != 0 {
400 return UnknownSignatureAlgorithm
404 if !ai.Algorithm.Equal(oidSignatureRSAPSS) {
405 for _, details := range signatureAlgorithmDetails {
406 if ai.Algorithm.Equal(details.oid) {
410 return UnknownSignatureAlgorithm
413 // RSA PSS is special because it encodes important parameters
414 // in the Parameters.
416 var params pssParameters
417 if _, err := asn1.Unmarshal(ai.Parameters.FullBytes, ¶ms); err != nil {
418 return UnknownSignatureAlgorithm
421 var mgf1HashFunc pkix.AlgorithmIdentifier
422 if _, err := asn1.Unmarshal(params.MGF.Parameters.FullBytes, &mgf1HashFunc); err != nil {
423 return UnknownSignatureAlgorithm
426 // PSS is greatly overburdened with options. This code forces them into
427 // three buckets by requiring that the MGF1 hash function always match the
428 // message hash function (as recommended in RFC 3447, Section 8.1), that the
429 // salt length matches the hash length, and that the trailer field has the
431 if (len(params.Hash.Parameters.FullBytes) != 0 && !bytes.Equal(params.Hash.Parameters.FullBytes, asn1.NullBytes)) ||
432 !params.MGF.Algorithm.Equal(oidMGF1) ||
433 !mgf1HashFunc.Algorithm.Equal(params.Hash.Algorithm) ||
434 (len(mgf1HashFunc.Parameters.FullBytes) != 0 && !bytes.Equal(mgf1HashFunc.Parameters.FullBytes, asn1.NullBytes)) ||
435 params.TrailerField != 1 {
436 return UnknownSignatureAlgorithm
440 case params.Hash.Algorithm.Equal(oidSHA256) && params.SaltLength == 32:
441 return SHA256WithRSAPSS
442 case params.Hash.Algorithm.Equal(oidSHA384) && params.SaltLength == 48:
443 return SHA384WithRSAPSS
444 case params.Hash.Algorithm.Equal(oidSHA512) && params.SaltLength == 64:
445 return SHA512WithRSAPSS
448 return UnknownSignatureAlgorithm
452 // RFC 3279, 2.3 Public Key Algorithms
454 // pkcs-1 OBJECT IDENTIFIER ::== { iso(1) member-body(2) us(840)
455 // rsadsi(113549) pkcs(1) 1 }
457 // rsaEncryption OBJECT IDENTIFIER ::== { pkcs1-1 1 }
459 // id-dsa OBJECT IDENTIFIER ::== { iso(1) member-body(2) us(840)
460 // x9-57(10040) x9cm(4) 1 }
461 oidPublicKeyRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 1}
462 oidPublicKeyDSA = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 1}
463 // RFC 5480, 2.1.1 Unrestricted Algorithm Identifier and Parameters
465 // id-ecPublicKey OBJECT IDENTIFIER ::= {
466 // iso(1) member-body(2) us(840) ansi-X9-62(10045) keyType(2) 1 }
467 oidPublicKeyECDSA = asn1.ObjectIdentifier{1, 2, 840, 10045, 2, 1}
468 // RFC 8410, Section 3
470 // id-X25519 OBJECT IDENTIFIER ::= { 1 3 101 110 }
471 // id-Ed25519 OBJECT IDENTIFIER ::= { 1 3 101 112 }
472 oidPublicKeyX25519 = asn1.ObjectIdentifier{1, 3, 101, 110}
473 oidPublicKeyEd25519 = asn1.ObjectIdentifier{1, 3, 101, 112}
476 // getPublicKeyAlgorithmFromOID returns the exposed PublicKeyAlgorithm
477 // identifier for public key types supported in certificates and CSRs. Marshal
478 // and Parse functions may support a different set of public key types.
479 func getPublicKeyAlgorithmFromOID(oid asn1.ObjectIdentifier) PublicKeyAlgorithm {
481 case oid.Equal(oidPublicKeyRSA):
483 case oid.Equal(oidPublicKeyDSA):
485 case oid.Equal(oidPublicKeyECDSA):
487 case oid.Equal(oidPublicKeyEd25519):
490 return UnknownPublicKeyAlgorithm
493 // RFC 5480, 2.1.1.1. Named Curve
495 // secp224r1 OBJECT IDENTIFIER ::= {
496 // iso(1) identified-organization(3) certicom(132) curve(0) 33 }
498 // secp256r1 OBJECT IDENTIFIER ::= {
499 // iso(1) member-body(2) us(840) ansi-X9-62(10045) curves(3)
502 // secp384r1 OBJECT IDENTIFIER ::= {
503 // iso(1) identified-organization(3) certicom(132) curve(0) 34 }
505 // secp521r1 OBJECT IDENTIFIER ::= {
506 // iso(1) identified-organization(3) certicom(132) curve(0) 35 }
508 // NB: secp256r1 is equivalent to prime256v1
510 oidNamedCurveP224 = asn1.ObjectIdentifier{1, 3, 132, 0, 33}
511 oidNamedCurveP256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 3, 1, 7}
512 oidNamedCurveP384 = asn1.ObjectIdentifier{1, 3, 132, 0, 34}
513 oidNamedCurveP521 = asn1.ObjectIdentifier{1, 3, 132, 0, 35}
516 func namedCurveFromOID(oid asn1.ObjectIdentifier) elliptic.Curve {
518 case oid.Equal(oidNamedCurveP224):
519 return elliptic.P224()
520 case oid.Equal(oidNamedCurveP256):
521 return elliptic.P256()
522 case oid.Equal(oidNamedCurveP384):
523 return elliptic.P384()
524 case oid.Equal(oidNamedCurveP521):
525 return elliptic.P521()
530 func oidFromNamedCurve(curve elliptic.Curve) (asn1.ObjectIdentifier, bool) {
532 case elliptic.P224():
533 return oidNamedCurveP224, true
534 case elliptic.P256():
535 return oidNamedCurveP256, true
536 case elliptic.P384():
537 return oidNamedCurveP384, true
538 case elliptic.P521():
539 return oidNamedCurveP521, true
545 // KeyUsage represents the set of actions that are valid for a given key. It's
546 // a bitmap of the KeyUsage* constants.
550 KeyUsageDigitalSignature KeyUsage = 1 << iota
551 KeyUsageContentCommitment
552 KeyUsageKeyEncipherment
553 KeyUsageDataEncipherment
561 // RFC 5280, 4.2.1.12 Extended Key Usage
563 // anyExtendedKeyUsage OBJECT IDENTIFIER ::= { id-ce-extKeyUsage 0 }
565 // id-kp OBJECT IDENTIFIER ::= { id-pkix 3 }
567 // id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 }
568 // id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 }
569 // id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 }
570 // id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 }
571 // id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 }
572 // id-kp-OCSPSigning OBJECT IDENTIFIER ::= { id-kp 9 }
574 oidExtKeyUsageAny = asn1.ObjectIdentifier{2, 5, 29, 37, 0}
575 oidExtKeyUsageServerAuth = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 1}
576 oidExtKeyUsageClientAuth = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 2}
577 oidExtKeyUsageCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 3}
578 oidExtKeyUsageEmailProtection = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 4}
579 oidExtKeyUsageIPSECEndSystem = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 5}
580 oidExtKeyUsageIPSECTunnel = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 6}
581 oidExtKeyUsageIPSECUser = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 7}
582 oidExtKeyUsageTimeStamping = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 8}
583 oidExtKeyUsageOCSPSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 9}
584 oidExtKeyUsageMicrosoftServerGatedCrypto = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 10, 3, 3}
585 oidExtKeyUsageNetscapeServerGatedCrypto = asn1.ObjectIdentifier{2, 16, 840, 1, 113730, 4, 1}
586 oidExtKeyUsageMicrosoftCommercialCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 2, 1, 22}
587 oidExtKeyUsageMicrosoftKernelCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 61, 1, 1}
590 // ExtKeyUsage represents an extended set of actions that are valid for a given key.
591 // Each of the ExtKeyUsage* constants define a unique action.
595 ExtKeyUsageAny ExtKeyUsage = iota
596 ExtKeyUsageServerAuth
597 ExtKeyUsageClientAuth
598 ExtKeyUsageCodeSigning
599 ExtKeyUsageEmailProtection
600 ExtKeyUsageIPSECEndSystem
601 ExtKeyUsageIPSECTunnel
603 ExtKeyUsageTimeStamping
604 ExtKeyUsageOCSPSigning
605 ExtKeyUsageMicrosoftServerGatedCrypto
606 ExtKeyUsageNetscapeServerGatedCrypto
607 ExtKeyUsageMicrosoftCommercialCodeSigning
608 ExtKeyUsageMicrosoftKernelCodeSigning
611 // extKeyUsageOIDs contains the mapping between an ExtKeyUsage and its OID.
612 var extKeyUsageOIDs = []struct {
613 extKeyUsage ExtKeyUsage
614 oid asn1.ObjectIdentifier
616 {ExtKeyUsageAny, oidExtKeyUsageAny},
617 {ExtKeyUsageServerAuth, oidExtKeyUsageServerAuth},
618 {ExtKeyUsageClientAuth, oidExtKeyUsageClientAuth},
619 {ExtKeyUsageCodeSigning, oidExtKeyUsageCodeSigning},
620 {ExtKeyUsageEmailProtection, oidExtKeyUsageEmailProtection},
621 {ExtKeyUsageIPSECEndSystem, oidExtKeyUsageIPSECEndSystem},
622 {ExtKeyUsageIPSECTunnel, oidExtKeyUsageIPSECTunnel},
623 {ExtKeyUsageIPSECUser, oidExtKeyUsageIPSECUser},
624 {ExtKeyUsageTimeStamping, oidExtKeyUsageTimeStamping},
625 {ExtKeyUsageOCSPSigning, oidExtKeyUsageOCSPSigning},
626 {ExtKeyUsageMicrosoftServerGatedCrypto, oidExtKeyUsageMicrosoftServerGatedCrypto},
627 {ExtKeyUsageNetscapeServerGatedCrypto, oidExtKeyUsageNetscapeServerGatedCrypto},
628 {ExtKeyUsageMicrosoftCommercialCodeSigning, oidExtKeyUsageMicrosoftCommercialCodeSigning},
629 {ExtKeyUsageMicrosoftKernelCodeSigning, oidExtKeyUsageMicrosoftKernelCodeSigning},
632 func extKeyUsageFromOID(oid asn1.ObjectIdentifier) (eku ExtKeyUsage, ok bool) {
633 for _, pair := range extKeyUsageOIDs {
634 if oid.Equal(pair.oid) {
635 return pair.extKeyUsage, true
641 func oidFromExtKeyUsage(eku ExtKeyUsage) (oid asn1.ObjectIdentifier, ok bool) {
642 for _, pair := range extKeyUsageOIDs {
643 if eku == pair.extKeyUsage {
644 return pair.oid, true
650 // A Certificate represents an X.509 certificate.
651 type Certificate struct {
652 Raw []byte // Complete ASN.1 DER content (certificate, signature algorithm and signature).
653 RawTBSCertificate []byte // Certificate part of raw ASN.1 DER content.
654 RawSubjectPublicKeyInfo []byte // DER encoded SubjectPublicKeyInfo.
655 RawSubject []byte // DER encoded Subject
656 RawIssuer []byte // DER encoded Issuer
659 SignatureAlgorithm SignatureAlgorithm
661 PublicKeyAlgorithm PublicKeyAlgorithm
665 SerialNumber *big.Int
668 NotBefore, NotAfter time.Time // Validity bounds.
671 // Extensions contains raw X.509 extensions. When parsing certificates,
672 // this can be used to extract non-critical extensions that are not
673 // parsed by this package. When marshaling certificates, the Extensions
674 // field is ignored, see ExtraExtensions.
675 Extensions []pkix.Extension
677 // ExtraExtensions contains extensions to be copied, raw, into any
678 // marshaled certificates. Values override any extensions that would
679 // otherwise be produced based on the other fields. The ExtraExtensions
680 // field is not populated when parsing certificates, see Extensions.
681 ExtraExtensions []pkix.Extension
683 // UnhandledCriticalExtensions contains a list of extension IDs that
684 // were not (fully) processed when parsing. Verify will fail if this
685 // slice is non-empty, unless verification is delegated to an OS
686 // library which understands all the critical extensions.
688 // Users can access these extensions using Extensions and can remove
689 // elements from this slice if they believe that they have been
691 UnhandledCriticalExtensions []asn1.ObjectIdentifier
693 ExtKeyUsage []ExtKeyUsage // Sequence of extended key usages.
694 UnknownExtKeyUsage []asn1.ObjectIdentifier // Encountered extended key usages unknown to this package.
696 // BasicConstraintsValid indicates whether IsCA, MaxPathLen,
697 // and MaxPathLenZero are valid.
698 BasicConstraintsValid bool
701 // MaxPathLen and MaxPathLenZero indicate the presence and
702 // value of the BasicConstraints' "pathLenConstraint".
704 // When parsing a certificate, a positive non-zero MaxPathLen
705 // means that the field was specified, -1 means it was unset,
706 // and MaxPathLenZero being true mean that the field was
707 // explicitly set to zero. The case of MaxPathLen==0 with MaxPathLenZero==false
708 // should be treated equivalent to -1 (unset).
710 // When generating a certificate, an unset pathLenConstraint
711 // can be requested with either MaxPathLen == -1 or using the
712 // zero value for both MaxPathLen and MaxPathLenZero.
714 // MaxPathLenZero indicates that BasicConstraintsValid==true
715 // and MaxPathLen==0 should be interpreted as an actual
716 // maximum path length of zero. Otherwise, that combination is
717 // interpreted as MaxPathLen not being set.
721 AuthorityKeyId []byte
723 // RFC 5280, 4.2.2.1 (Authority Information Access)
725 IssuingCertificateURL []string
727 // Subject Alternate Name values. (Note that these values may not be valid
728 // if invalid values were contained within a parsed certificate. For
729 // example, an element of DNSNames may not be a valid DNS domain name.)
731 EmailAddresses []string
736 PermittedDNSDomainsCritical bool // if true then the name constraints are marked critical.
737 PermittedDNSDomains []string
738 ExcludedDNSDomains []string
739 PermittedIPRanges []*net.IPNet
740 ExcludedIPRanges []*net.IPNet
741 PermittedEmailAddresses []string
742 ExcludedEmailAddresses []string
743 PermittedURIDomains []string
744 ExcludedURIDomains []string
746 // CRL Distribution Points
747 CRLDistributionPoints []string
749 PolicyIdentifiers []asn1.ObjectIdentifier
752 // ErrUnsupportedAlgorithm results from attempting to perform an operation that
753 // involves algorithms that are not currently implemented.
754 var ErrUnsupportedAlgorithm = errors.New("x509: cannot verify signature: algorithm unimplemented")
756 // An InsecureAlgorithmError indicates that the SignatureAlgorithm used to
757 // generate the signature is not secure, and the signature has been rejected.
759 // To temporarily restore support for SHA-1 signatures, include the value
760 // "x509sha1=1" in the GODEBUG environment variable. Note that this option will
761 // be removed in a future release.
762 type InsecureAlgorithmError SignatureAlgorithm
764 func (e InsecureAlgorithmError) Error() string {
766 if SignatureAlgorithm(e) == SHA1WithRSA || SignatureAlgorithm(e) == ECDSAWithSHA1 {
767 override = " (temporarily override with GODEBUG=x509sha1=1)"
769 return fmt.Sprintf("x509: cannot verify signature: insecure algorithm %v", SignatureAlgorithm(e)) + override
772 // ConstraintViolationError results when a requested usage is not permitted by
773 // a certificate. For example: checking a signature when the public key isn't a
774 // certificate signing key.
775 type ConstraintViolationError struct{}
777 func (ConstraintViolationError) Error() string {
778 return "x509: invalid signature: parent certificate cannot sign this kind of certificate"
781 func (c *Certificate) Equal(other *Certificate) bool {
782 if c == nil || other == nil {
785 return bytes.Equal(c.Raw, other.Raw)
788 func (c *Certificate) hasSANExtension() bool {
789 return oidInExtensions(oidExtensionSubjectAltName, c.Extensions)
792 // CheckSignatureFrom verifies that the signature on c is a valid signature
793 // from parent. SHA1WithRSA and ECDSAWithSHA1 signatures are not supported.
794 func (c *Certificate) CheckSignatureFrom(parent *Certificate) error {
795 // RFC 5280, 4.2.1.9:
796 // "If the basic constraints extension is not present in a version 3
797 // certificate, or the extension is present but the cA boolean is not
798 // asserted, then the certified public key MUST NOT be used to verify
799 // certificate signatures."
800 if parent.Version == 3 && !parent.BasicConstraintsValid ||
801 parent.BasicConstraintsValid && !parent.IsCA {
802 return ConstraintViolationError{}
805 if parent.KeyUsage != 0 && parent.KeyUsage&KeyUsageCertSign == 0 {
806 return ConstraintViolationError{}
809 if parent.PublicKeyAlgorithm == UnknownPublicKeyAlgorithm {
810 return ErrUnsupportedAlgorithm
813 // TODO(agl): don't ignore the path length constraint.
815 return checkSignature(c.SignatureAlgorithm, c.RawTBSCertificate, c.Signature, parent.PublicKey, false)
818 // CheckSignature verifies that signature is a valid signature over signed from
820 func (c *Certificate) CheckSignature(algo SignatureAlgorithm, signed, signature []byte) error {
821 return checkSignature(algo, signed, signature, c.PublicKey, true)
824 func (c *Certificate) hasNameConstraints() bool {
825 return oidInExtensions(oidExtensionNameConstraints, c.Extensions)
828 func (c *Certificate) getSANExtension() []byte {
829 for _, e := range c.Extensions {
830 if e.Id.Equal(oidExtensionSubjectAltName) {
837 func signaturePublicKeyAlgoMismatchError(expectedPubKeyAlgo PublicKeyAlgorithm, pubKey any) error {
838 return fmt.Errorf("x509: signature algorithm specifies an %s public key, but have public key of type %T", expectedPubKeyAlgo.String(), pubKey)
841 var x509sha1 = godebug.New("x509sha1")
843 // checkSignature verifies that signature is a valid signature over signed from
844 // a crypto.PublicKey.
845 func checkSignature(algo SignatureAlgorithm, signed, signature []byte, publicKey crypto.PublicKey, allowSHA1 bool) (err error) {
846 var hashType crypto.Hash
847 var pubKeyAlgo PublicKeyAlgorithm
849 for _, details := range signatureAlgorithmDetails {
850 if details.algo == algo {
851 hashType = details.hash
852 pubKeyAlgo = details.pubKeyAlgo
858 if pubKeyAlgo != Ed25519 {
859 return ErrUnsupportedAlgorithm
862 return InsecureAlgorithmError(algo)
864 // SHA-1 signatures are mostly disabled. See go.dev/issue/41682.
865 if !allowSHA1 && x509sha1.Value() != "1" {
866 return InsecureAlgorithmError(algo)
870 if !hashType.Available() {
871 return ErrUnsupportedAlgorithm
878 switch pub := publicKey.(type) {
880 if pubKeyAlgo != RSA {
881 return signaturePublicKeyAlgoMismatchError(pubKeyAlgo, pub)
884 return rsa.VerifyPSS(pub, hashType, signed, signature, &rsa.PSSOptions{SaltLength: rsa.PSSSaltLengthEqualsHash})
886 return rsa.VerifyPKCS1v15(pub, hashType, signed, signature)
888 case *ecdsa.PublicKey:
889 if pubKeyAlgo != ECDSA {
890 return signaturePublicKeyAlgoMismatchError(pubKeyAlgo, pub)
892 if !ecdsa.VerifyASN1(pub, signed, signature) {
893 return errors.New("x509: ECDSA verification failure")
896 case ed25519.PublicKey:
897 if pubKeyAlgo != Ed25519 {
898 return signaturePublicKeyAlgoMismatchError(pubKeyAlgo, pub)
900 if !ed25519.Verify(pub, signed, signature) {
901 return errors.New("x509: Ed25519 verification failure")
905 return ErrUnsupportedAlgorithm
908 // CheckCRLSignature checks that the signature in crl is from c.
910 // Deprecated: Use RevocationList.CheckSignatureFrom instead.
911 func (c *Certificate) CheckCRLSignature(crl *pkix.CertificateList) error {
912 algo := getSignatureAlgorithmFromAI(crl.SignatureAlgorithm)
913 return c.CheckSignature(algo, crl.TBSCertList.Raw, crl.SignatureValue.RightAlign())
916 type UnhandledCriticalExtension struct{}
918 func (h UnhandledCriticalExtension) Error() string {
919 return "x509: unhandled critical extension"
922 type basicConstraints struct {
923 IsCA bool `asn1:"optional"`
924 MaxPathLen int `asn1:"optional,default:-1"`
928 type policyInformation struct {
929 Policy asn1.ObjectIdentifier
930 // policyQualifiers omitted
941 type authorityInfoAccess struct {
942 Method asn1.ObjectIdentifier
943 Location asn1.RawValue
946 // RFC 5280, 4.2.1.14
947 type distributionPoint struct {
948 DistributionPoint distributionPointName `asn1:"optional,tag:0"`
949 Reason asn1.BitString `asn1:"optional,tag:1"`
950 CRLIssuer asn1.RawValue `asn1:"optional,tag:2"`
953 type distributionPointName struct {
954 FullName []asn1.RawValue `asn1:"optional,tag:0"`
955 RelativeName pkix.RDNSequence `asn1:"optional,tag:1"`
958 func reverseBitsInAByte(in byte) byte {
960 b2 := b1>>2&0x33 | b1<<2&0xcc
961 b3 := b2>>1&0x55 | b2<<1&0xaa
965 // asn1BitLength returns the bit-length of bitString by considering the
966 // most-significant bit in a byte to be the "first" bit. This convention
967 // matches ASN.1, but differs from almost everything else.
968 func asn1BitLength(bitString []byte) int {
969 bitLen := len(bitString) * 8
971 for i := range bitString {
972 b := bitString[len(bitString)-i-1]
974 for bit := uint(0); bit < 8; bit++ {
986 oidExtensionSubjectKeyId = []int{2, 5, 29, 14}
987 oidExtensionKeyUsage = []int{2, 5, 29, 15}
988 oidExtensionExtendedKeyUsage = []int{2, 5, 29, 37}
989 oidExtensionAuthorityKeyId = []int{2, 5, 29, 35}
990 oidExtensionBasicConstraints = []int{2, 5, 29, 19}
991 oidExtensionSubjectAltName = []int{2, 5, 29, 17}
992 oidExtensionCertificatePolicies = []int{2, 5, 29, 32}
993 oidExtensionNameConstraints = []int{2, 5, 29, 30}
994 oidExtensionCRLDistributionPoints = []int{2, 5, 29, 31}
995 oidExtensionAuthorityInfoAccess = []int{1, 3, 6, 1, 5, 5, 7, 1, 1}
996 oidExtensionCRLNumber = []int{2, 5, 29, 20}
1000 oidAuthorityInfoAccessOcsp = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 48, 1}
1001 oidAuthorityInfoAccessIssuers = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 48, 2}
1004 // oidInExtensions reports whether an extension with the given oid exists in
1006 func oidInExtensions(oid asn1.ObjectIdentifier, extensions []pkix.Extension) bool {
1007 for _, e := range extensions {
1008 if e.Id.Equal(oid) {
1015 // marshalSANs marshals a list of addresses into a the contents of an X.509
1016 // SubjectAlternativeName extension.
1017 func marshalSANs(dnsNames, emailAddresses []string, ipAddresses []net.IP, uris []*url.URL) (derBytes []byte, err error) {
1018 var rawValues []asn1.RawValue
1019 for _, name := range dnsNames {
1020 if err := isIA5String(name); err != nil {
1023 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeDNS, Class: 2, Bytes: []byte(name)})
1025 for _, email := range emailAddresses {
1026 if err := isIA5String(email); err != nil {
1029 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeEmail, Class: 2, Bytes: []byte(email)})
1031 for _, rawIP := range ipAddresses {
1032 // If possible, we always want to encode IPv4 addresses in 4 bytes.
1037 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeIP, Class: 2, Bytes: ip})
1039 for _, uri := range uris {
1040 uriStr := uri.String()
1041 if err := isIA5String(uriStr); err != nil {
1044 rawValues = append(rawValues, asn1.RawValue{Tag: nameTypeURI, Class: 2, Bytes: []byte(uriStr)})
1046 return asn1.Marshal(rawValues)
1049 func isIA5String(s string) error {
1050 for _, r := range s {
1051 // Per RFC5280 "IA5String is limited to the set of ASCII characters"
1052 if r > unicode.MaxASCII {
1053 return fmt.Errorf("x509: %q cannot be encoded as an IA5String", s)
1060 func buildCertExtensions(template *Certificate, subjectIsEmpty bool, authorityKeyId []byte, subjectKeyId []byte) (ret []pkix.Extension, err error) {
1061 ret = make([]pkix.Extension, 10 /* maximum number of elements. */)
1064 if template.KeyUsage != 0 &&
1065 !oidInExtensions(oidExtensionKeyUsage, template.ExtraExtensions) {
1066 ret[n], err = marshalKeyUsage(template.KeyUsage)
1073 if (len(template.ExtKeyUsage) > 0 || len(template.UnknownExtKeyUsage) > 0) &&
1074 !oidInExtensions(oidExtensionExtendedKeyUsage, template.ExtraExtensions) {
1075 ret[n], err = marshalExtKeyUsage(template.ExtKeyUsage, template.UnknownExtKeyUsage)
1082 if template.BasicConstraintsValid && !oidInExtensions(oidExtensionBasicConstraints, template.ExtraExtensions) {
1083 ret[n], err = marshalBasicConstraints(template.IsCA, template.MaxPathLen, template.MaxPathLenZero)
1090 if len(subjectKeyId) > 0 && !oidInExtensions(oidExtensionSubjectKeyId, template.ExtraExtensions) {
1091 ret[n].Id = oidExtensionSubjectKeyId
1092 ret[n].Value, err = asn1.Marshal(subjectKeyId)
1099 if len(authorityKeyId) > 0 && !oidInExtensions(oidExtensionAuthorityKeyId, template.ExtraExtensions) {
1100 ret[n].Id = oidExtensionAuthorityKeyId
1101 ret[n].Value, err = asn1.Marshal(authKeyId{authorityKeyId})
1108 if (len(template.OCSPServer) > 0 || len(template.IssuingCertificateURL) > 0) &&
1109 !oidInExtensions(oidExtensionAuthorityInfoAccess, template.ExtraExtensions) {
1110 ret[n].Id = oidExtensionAuthorityInfoAccess
1111 var aiaValues []authorityInfoAccess
1112 for _, name := range template.OCSPServer {
1113 aiaValues = append(aiaValues, authorityInfoAccess{
1114 Method: oidAuthorityInfoAccessOcsp,
1115 Location: asn1.RawValue{Tag: 6, Class: 2, Bytes: []byte(name)},
1118 for _, name := range template.IssuingCertificateURL {
1119 aiaValues = append(aiaValues, authorityInfoAccess{
1120 Method: oidAuthorityInfoAccessIssuers,
1121 Location: asn1.RawValue{Tag: 6, Class: 2, Bytes: []byte(name)},
1124 ret[n].Value, err = asn1.Marshal(aiaValues)
1131 if (len(template.DNSNames) > 0 || len(template.EmailAddresses) > 0 || len(template.IPAddresses) > 0 || len(template.URIs) > 0) &&
1132 !oidInExtensions(oidExtensionSubjectAltName, template.ExtraExtensions) {
1133 ret[n].Id = oidExtensionSubjectAltName
1134 // From RFC 5280, Section 4.2.1.6:
1135 // “If the subject field contains an empty sequence ... then
1136 // subjectAltName extension ... is marked as critical”
1137 ret[n].Critical = subjectIsEmpty
1138 ret[n].Value, err = marshalSANs(template.DNSNames, template.EmailAddresses, template.IPAddresses, template.URIs)
1145 if len(template.PolicyIdentifiers) > 0 &&
1146 !oidInExtensions(oidExtensionCertificatePolicies, template.ExtraExtensions) {
1147 ret[n], err = marshalCertificatePolicies(template.PolicyIdentifiers)
1154 if (len(template.PermittedDNSDomains) > 0 || len(template.ExcludedDNSDomains) > 0 ||
1155 len(template.PermittedIPRanges) > 0 || len(template.ExcludedIPRanges) > 0 ||
1156 len(template.PermittedEmailAddresses) > 0 || len(template.ExcludedEmailAddresses) > 0 ||
1157 len(template.PermittedURIDomains) > 0 || len(template.ExcludedURIDomains) > 0) &&
1158 !oidInExtensions(oidExtensionNameConstraints, template.ExtraExtensions) {
1159 ret[n].Id = oidExtensionNameConstraints
1160 ret[n].Critical = template.PermittedDNSDomainsCritical
1162 ipAndMask := func(ipNet *net.IPNet) []byte {
1163 maskedIP := ipNet.IP.Mask(ipNet.Mask)
1164 ipAndMask := make([]byte, 0, len(maskedIP)+len(ipNet.Mask))
1165 ipAndMask = append(ipAndMask, maskedIP...)
1166 ipAndMask = append(ipAndMask, ipNet.Mask...)
1170 serialiseConstraints := func(dns []string, ips []*net.IPNet, emails []string, uriDomains []string) (der []byte, err error) {
1171 var b cryptobyte.Builder
1173 for _, name := range dns {
1174 if err = isIA5String(name); err != nil {
1178 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1179 b.AddASN1(cryptobyte_asn1.Tag(2).ContextSpecific(), func(b *cryptobyte.Builder) {
1180 b.AddBytes([]byte(name))
1185 for _, ipNet := range ips {
1186 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1187 b.AddASN1(cryptobyte_asn1.Tag(7).ContextSpecific(), func(b *cryptobyte.Builder) {
1188 b.AddBytes(ipAndMask(ipNet))
1193 for _, email := range emails {
1194 if err = isIA5String(email); err != nil {
1198 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1199 b.AddASN1(cryptobyte_asn1.Tag(1).ContextSpecific(), func(b *cryptobyte.Builder) {
1200 b.AddBytes([]byte(email))
1205 for _, uriDomain := range uriDomains {
1206 if err = isIA5String(uriDomain); err != nil {
1210 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1211 b.AddASN1(cryptobyte_asn1.Tag(6).ContextSpecific(), func(b *cryptobyte.Builder) {
1212 b.AddBytes([]byte(uriDomain))
1220 permitted, err := serialiseConstraints(template.PermittedDNSDomains, template.PermittedIPRanges, template.PermittedEmailAddresses, template.PermittedURIDomains)
1225 excluded, err := serialiseConstraints(template.ExcludedDNSDomains, template.ExcludedIPRanges, template.ExcludedEmailAddresses, template.ExcludedURIDomains)
1230 var b cryptobyte.Builder
1231 b.AddASN1(cryptobyte_asn1.SEQUENCE, func(b *cryptobyte.Builder) {
1232 if len(permitted) > 0 {
1233 b.AddASN1(cryptobyte_asn1.Tag(0).ContextSpecific().Constructed(), func(b *cryptobyte.Builder) {
1234 b.AddBytes(permitted)
1238 if len(excluded) > 0 {
1239 b.AddASN1(cryptobyte_asn1.Tag(1).ContextSpecific().Constructed(), func(b *cryptobyte.Builder) {
1240 b.AddBytes(excluded)
1245 ret[n].Value, err = b.Bytes()
1252 if len(template.CRLDistributionPoints) > 0 &&
1253 !oidInExtensions(oidExtensionCRLDistributionPoints, template.ExtraExtensions) {
1254 ret[n].Id = oidExtensionCRLDistributionPoints
1256 var crlDp []distributionPoint
1257 for _, name := range template.CRLDistributionPoints {
1258 dp := distributionPoint{
1259 DistributionPoint: distributionPointName{
1260 FullName: []asn1.RawValue{
1261 {Tag: 6, Class: 2, Bytes: []byte(name)},
1265 crlDp = append(crlDp, dp)
1268 ret[n].Value, err = asn1.Marshal(crlDp)
1275 // Adding another extension here? Remember to update the maximum number
1276 // of elements in the make() at the top of the function and the list of
1277 // template fields used in CreateCertificate documentation.
1279 return append(ret[:n], template.ExtraExtensions...), nil
1282 func marshalKeyUsage(ku KeyUsage) (pkix.Extension, error) {
1283 ext := pkix.Extension{Id: oidExtensionKeyUsage, Critical: true}
1286 a[0] = reverseBitsInAByte(byte(ku))
1287 a[1] = reverseBitsInAByte(byte(ku >> 8))
1296 ext.Value, err = asn1.Marshal(asn1.BitString{Bytes: bitString, BitLength: asn1BitLength(bitString)})
1300 func marshalExtKeyUsage(extUsages []ExtKeyUsage, unknownUsages []asn1.ObjectIdentifier) (pkix.Extension, error) {
1301 ext := pkix.Extension{Id: oidExtensionExtendedKeyUsage}
1303 oids := make([]asn1.ObjectIdentifier, len(extUsages)+len(unknownUsages))
1304 for i, u := range extUsages {
1305 if oid, ok := oidFromExtKeyUsage(u); ok {
1308 return ext, errors.New("x509: unknown extended key usage")
1312 copy(oids[len(extUsages):], unknownUsages)
1315 ext.Value, err = asn1.Marshal(oids)
1319 func marshalBasicConstraints(isCA bool, maxPathLen int, maxPathLenZero bool) (pkix.Extension, error) {
1320 ext := pkix.Extension{Id: oidExtensionBasicConstraints, Critical: true}
1321 // Leaving MaxPathLen as zero indicates that no maximum path
1322 // length is desired, unless MaxPathLenZero is set. A value of
1323 // -1 causes encoding/asn1 to omit the value as desired.
1324 if maxPathLen == 0 && !maxPathLenZero {
1328 ext.Value, err = asn1.Marshal(basicConstraints{isCA, maxPathLen})
1332 func marshalCertificatePolicies(policyIdentifiers []asn1.ObjectIdentifier) (pkix.Extension, error) {
1333 ext := pkix.Extension{Id: oidExtensionCertificatePolicies}
1334 policies := make([]policyInformation, len(policyIdentifiers))
1335 for i, policy := range policyIdentifiers {
1336 policies[i].Policy = policy
1339 ext.Value, err = asn1.Marshal(policies)
1343 func buildCSRExtensions(template *CertificateRequest) ([]pkix.Extension, error) {
1344 var ret []pkix.Extension
1346 if (len(template.DNSNames) > 0 || len(template.EmailAddresses) > 0 || len(template.IPAddresses) > 0 || len(template.URIs) > 0) &&
1347 !oidInExtensions(oidExtensionSubjectAltName, template.ExtraExtensions) {
1348 sanBytes, err := marshalSANs(template.DNSNames, template.EmailAddresses, template.IPAddresses, template.URIs)
1353 ret = append(ret, pkix.Extension{
1354 Id: oidExtensionSubjectAltName,
1359 return append(ret, template.ExtraExtensions...), nil
1362 func subjectBytes(cert *Certificate) ([]byte, error) {
1363 if len(cert.RawSubject) > 0 {
1364 return cert.RawSubject, nil
1367 return asn1.Marshal(cert.Subject.ToRDNSequence())
1370 // signingParamsForPublicKey returns the parameters to use for signing with
1371 // priv. If requestedSigAlgo is not zero then it overrides the default
1372 // signature algorithm.
1373 func signingParamsForPublicKey(pub any, requestedSigAlgo SignatureAlgorithm) (hashFunc crypto.Hash, sigAlgo pkix.AlgorithmIdentifier, err error) {
1374 var pubType PublicKeyAlgorithm
1376 switch pub := pub.(type) {
1377 case *rsa.PublicKey:
1379 hashFunc = crypto.SHA256
1380 sigAlgo.Algorithm = oidSignatureSHA256WithRSA
1381 sigAlgo.Parameters = asn1.NullRawValue
1383 case *ecdsa.PublicKey:
1387 case elliptic.P224(), elliptic.P256():
1388 hashFunc = crypto.SHA256
1389 sigAlgo.Algorithm = oidSignatureECDSAWithSHA256
1390 case elliptic.P384():
1391 hashFunc = crypto.SHA384
1392 sigAlgo.Algorithm = oidSignatureECDSAWithSHA384
1393 case elliptic.P521():
1394 hashFunc = crypto.SHA512
1395 sigAlgo.Algorithm = oidSignatureECDSAWithSHA512
1397 err = errors.New("x509: unknown elliptic curve")
1400 case ed25519.PublicKey:
1402 sigAlgo.Algorithm = oidSignatureEd25519
1405 err = errors.New("x509: only RSA, ECDSA and Ed25519 keys supported")
1412 if requestedSigAlgo == 0 {
1417 for _, details := range signatureAlgorithmDetails {
1418 if details.algo == requestedSigAlgo {
1419 if details.pubKeyAlgo != pubType {
1420 err = errors.New("x509: requested SignatureAlgorithm does not match private key type")
1423 sigAlgo.Algorithm, hashFunc = details.oid, details.hash
1424 if hashFunc == 0 && pubType != Ed25519 {
1425 err = errors.New("x509: cannot sign with hash function requested")
1428 if hashFunc == crypto.MD5 {
1429 err = errors.New("x509: signing with MD5 is not supported")
1432 if requestedSigAlgo.isRSAPSS() {
1433 sigAlgo.Parameters = hashToPSSParameters[hashFunc]
1441 err = errors.New("x509: unknown SignatureAlgorithm")
1447 // emptyASN1Subject is the ASN.1 DER encoding of an empty Subject, which is
1448 // just an empty SEQUENCE.
1449 var emptyASN1Subject = []byte{0x30, 0}
1451 // CreateCertificate creates a new X.509 v3 certificate based on a template.
1452 // The following members of template are currently used:
1455 // - BasicConstraintsValid
1456 // - CRLDistributionPoints
1459 // - ExcludedDNSDomains
1460 // - ExcludedEmailAddresses
1461 // - ExcludedIPRanges
1462 // - ExcludedURIDomains
1464 // - ExtraExtensions
1467 // - IssuingCertificateURL
1474 // - PermittedDNSDomains
1475 // - PermittedDNSDomainsCritical
1476 // - PermittedEmailAddresses
1477 // - PermittedIPRanges
1478 // - PermittedURIDomains
1479 // - PolicyIdentifiers
1481 // - SignatureAlgorithm
1485 // - UnknownExtKeyUsage
1487 // The certificate is signed by parent. If parent is equal to template then the
1488 // certificate is self-signed. The parameter pub is the public key of the
1489 // certificate to be generated and priv is the private key of the signer.
1491 // The returned slice is the certificate in DER encoding.
1493 // The currently supported key types are *rsa.PublicKey, *ecdsa.PublicKey and
1494 // ed25519.PublicKey. pub must be a supported key type, and priv must be a
1495 // crypto.Signer with a supported public key.
1497 // The AuthorityKeyId will be taken from the SubjectKeyId of parent, if any,
1498 // unless the resulting certificate is self-signed. Otherwise the value from
1499 // template will be used.
1501 // If SubjectKeyId from template is empty and the template is a CA, SubjectKeyId
1502 // will be generated from the hash of the public key.
1503 func CreateCertificate(rand io.Reader, template, parent *Certificate, pub, priv any) ([]byte, error) {
1504 key, ok := priv.(crypto.Signer)
1506 return nil, errors.New("x509: certificate private key does not implement crypto.Signer")
1509 if template.SerialNumber == nil {
1510 return nil, errors.New("x509: no SerialNumber given")
1513 // RFC 5280 Section 4.1.2.2: serial number must positive
1515 // We _should_ also restrict serials to <= 20 octets, but it turns out a lot of people
1516 // get this wrong, in part because the encoding can itself alter the length of the
1517 // serial. For now we accept these non-conformant serials.
1518 if template.SerialNumber.Sign() == -1 {
1519 return nil, errors.New("x509: serial number must be positive")
1522 if template.BasicConstraintsValid && !template.IsCA && template.MaxPathLen != -1 && (template.MaxPathLen != 0 || template.MaxPathLenZero) {
1523 return nil, errors.New("x509: only CAs are allowed to specify MaxPathLen")
1526 hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(key.Public(), template.SignatureAlgorithm)
1531 publicKeyBytes, publicKeyAlgorithm, err := marshalPublicKey(pub)
1535 if getPublicKeyAlgorithmFromOID(publicKeyAlgorithm.Algorithm) == UnknownPublicKeyAlgorithm {
1536 return nil, fmt.Errorf("x509: unsupported public key type: %T", pub)
1539 asn1Issuer, err := subjectBytes(parent)
1544 asn1Subject, err := subjectBytes(template)
1549 authorityKeyId := template.AuthorityKeyId
1550 if !bytes.Equal(asn1Issuer, asn1Subject) && len(parent.SubjectKeyId) > 0 {
1551 authorityKeyId = parent.SubjectKeyId
1554 subjectKeyId := template.SubjectKeyId
1555 if len(subjectKeyId) == 0 && template.IsCA {
1556 // SubjectKeyId generated using method 1 in RFC 5280, Section 4.2.1.2:
1557 // (1) The keyIdentifier is composed of the 160-bit SHA-1 hash of the
1558 // value of the BIT STRING subjectPublicKey (excluding the tag,
1559 // length, and number of unused bits).
1560 h := sha1.Sum(publicKeyBytes)
1564 // Check that the signer's public key matches the private key, if available.
1565 type privateKey interface {
1566 Equal(crypto.PublicKey) bool
1568 if privPub, ok := key.Public().(privateKey); !ok {
1569 return nil, errors.New("x509: internal error: supported public key does not implement Equal")
1570 } else if parent.PublicKey != nil && !privPub.Equal(parent.PublicKey) {
1571 return nil, errors.New("x509: provided PrivateKey doesn't match parent's PublicKey")
1574 extensions, err := buildCertExtensions(template, bytes.Equal(asn1Subject, emptyASN1Subject), authorityKeyId, subjectKeyId)
1579 encodedPublicKey := asn1.BitString{BitLength: len(publicKeyBytes) * 8, Bytes: publicKeyBytes}
1580 c := tbsCertificate{
1582 SerialNumber: template.SerialNumber,
1583 SignatureAlgorithm: signatureAlgorithm,
1584 Issuer: asn1.RawValue{FullBytes: asn1Issuer},
1585 Validity: validity{template.NotBefore.UTC(), template.NotAfter.UTC()},
1586 Subject: asn1.RawValue{FullBytes: asn1Subject},
1587 PublicKey: publicKeyInfo{nil, publicKeyAlgorithm, encodedPublicKey},
1588 Extensions: extensions,
1591 tbsCertContents, err := asn1.Marshal(c)
1595 c.Raw = tbsCertContents
1597 signed := tbsCertContents
1604 var signerOpts crypto.SignerOpts = hashFunc
1605 if template.SignatureAlgorithm != 0 && template.SignatureAlgorithm.isRSAPSS() {
1606 signerOpts = &rsa.PSSOptions{
1607 SaltLength: rsa.PSSSaltLengthEqualsHash,
1612 var signature []byte
1613 signature, err = key.Sign(rand, signed, signerOpts)
1618 signedCert, err := asn1.Marshal(certificate{
1621 asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
1627 // Check the signature to ensure the crypto.Signer behaved correctly.
1628 if err := checkSignature(getSignatureAlgorithmFromAI(signatureAlgorithm), c.Raw, signature, key.Public(), true); err != nil {
1629 return nil, fmt.Errorf("x509: signature over certificate returned by signer is invalid: %w", err)
1632 return signedCert, nil
1635 // pemCRLPrefix is the magic string that indicates that we have a PEM encoded
1637 var pemCRLPrefix = []byte("-----BEGIN X509 CRL")
1639 // pemType is the type of a PEM encoded CRL.
1640 var pemType = "X509 CRL"
1642 // ParseCRL parses a CRL from the given bytes. It's often the case that PEM
1643 // encoded CRLs will appear where they should be DER encoded, so this function
1644 // will transparently handle PEM encoding as long as there isn't any leading
1647 // Deprecated: Use ParseRevocationList instead.
1648 func ParseCRL(crlBytes []byte) (*pkix.CertificateList, error) {
1649 if bytes.HasPrefix(crlBytes, pemCRLPrefix) {
1650 block, _ := pem.Decode(crlBytes)
1651 if block != nil && block.Type == pemType {
1652 crlBytes = block.Bytes
1655 return ParseDERCRL(crlBytes)
1658 // ParseDERCRL parses a DER encoded CRL from the given bytes.
1660 // Deprecated: Use ParseRevocationList instead.
1661 func ParseDERCRL(derBytes []byte) (*pkix.CertificateList, error) {
1662 certList := new(pkix.CertificateList)
1663 if rest, err := asn1.Unmarshal(derBytes, certList); err != nil {
1665 } else if len(rest) != 0 {
1666 return nil, errors.New("x509: trailing data after CRL")
1668 return certList, nil
1671 // CreateCRL returns a DER encoded CRL, signed by this Certificate, that
1672 // contains the given list of revoked certificates.
1674 // Deprecated: this method does not generate an RFC 5280 conformant X.509 v2 CRL.
1675 // To generate a standards compliant CRL, use CreateRevocationList instead.
1676 func (c *Certificate) CreateCRL(rand io.Reader, priv any, revokedCerts []pkix.RevokedCertificate, now, expiry time.Time) (crlBytes []byte, err error) {
1677 key, ok := priv.(crypto.Signer)
1679 return nil, errors.New("x509: certificate private key does not implement crypto.Signer")
1682 hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(key.Public(), 0)
1687 // Force revocation times to UTC per RFC 5280.
1688 revokedCertsUTC := make([]pkix.RevokedCertificate, len(revokedCerts))
1689 for i, rc := range revokedCerts {
1690 rc.RevocationTime = rc.RevocationTime.UTC()
1691 revokedCertsUTC[i] = rc
1694 tbsCertList := pkix.TBSCertificateList{
1696 Signature: signatureAlgorithm,
1697 Issuer: c.Subject.ToRDNSequence(),
1698 ThisUpdate: now.UTC(),
1699 NextUpdate: expiry.UTC(),
1700 RevokedCertificates: revokedCertsUTC,
1704 if len(c.SubjectKeyId) > 0 {
1705 var aki pkix.Extension
1706 aki.Id = oidExtensionAuthorityKeyId
1707 aki.Value, err = asn1.Marshal(authKeyId{Id: c.SubjectKeyId})
1711 tbsCertList.Extensions = append(tbsCertList.Extensions, aki)
1714 tbsCertListContents, err := asn1.Marshal(tbsCertList)
1719 signed := tbsCertListContents
1726 var signature []byte
1727 signature, err = key.Sign(rand, signed, hashFunc)
1732 return asn1.Marshal(pkix.CertificateList{
1733 TBSCertList: tbsCertList,
1734 SignatureAlgorithm: signatureAlgorithm,
1735 SignatureValue: asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
1739 // CertificateRequest represents a PKCS #10, certificate signature request.
1740 type CertificateRequest struct {
1741 Raw []byte // Complete ASN.1 DER content (CSR, signature algorithm and signature).
1742 RawTBSCertificateRequest []byte // Certificate request info part of raw ASN.1 DER content.
1743 RawSubjectPublicKeyInfo []byte // DER encoded SubjectPublicKeyInfo.
1744 RawSubject []byte // DER encoded Subject.
1748 SignatureAlgorithm SignatureAlgorithm
1750 PublicKeyAlgorithm PublicKeyAlgorithm
1755 // Attributes contains the CSR attributes that can parse as
1756 // pkix.AttributeTypeAndValueSET.
1758 // Deprecated: Use Extensions and ExtraExtensions instead for parsing and
1759 // generating the requestedExtensions attribute.
1760 Attributes []pkix.AttributeTypeAndValueSET
1762 // Extensions contains all requested extensions, in raw form. When parsing
1763 // CSRs, this can be used to extract extensions that are not parsed by this
1765 Extensions []pkix.Extension
1767 // ExtraExtensions contains extensions to be copied, raw, into any CSR
1768 // marshaled by CreateCertificateRequest. Values override any extensions
1769 // that would otherwise be produced based on the other fields but are
1770 // overridden by any extensions specified in Attributes.
1772 // The ExtraExtensions field is not populated by ParseCertificateRequest,
1773 // see Extensions instead.
1774 ExtraExtensions []pkix.Extension
1776 // Subject Alternate Name values.
1778 EmailAddresses []string
1779 IPAddresses []net.IP
1783 // These structures reflect the ASN.1 structure of X.509 certificate
1784 // signature requests (see RFC 2986):
1786 type tbsCertificateRequest struct {
1789 Subject asn1.RawValue
1790 PublicKey publicKeyInfo
1791 RawAttributes []asn1.RawValue `asn1:"tag:0"`
1794 type certificateRequest struct {
1796 TBSCSR tbsCertificateRequest
1797 SignatureAlgorithm pkix.AlgorithmIdentifier
1798 SignatureValue asn1.BitString
1801 // oidExtensionRequest is a PKCS #9 OBJECT IDENTIFIER that indicates requested
1802 // extensions in a CSR.
1803 var oidExtensionRequest = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 9, 14}
1805 // newRawAttributes converts AttributeTypeAndValueSETs from a template
1806 // CertificateRequest's Attributes into tbsCertificateRequest RawAttributes.
1807 func newRawAttributes(attributes []pkix.AttributeTypeAndValueSET) ([]asn1.RawValue, error) {
1808 var rawAttributes []asn1.RawValue
1809 b, err := asn1.Marshal(attributes)
1813 rest, err := asn1.Unmarshal(b, &rawAttributes)
1818 return nil, errors.New("x509: failed to unmarshal raw CSR Attributes")
1820 return rawAttributes, nil
1823 // parseRawAttributes Unmarshals RawAttributes into AttributeTypeAndValueSETs.
1824 func parseRawAttributes(rawAttributes []asn1.RawValue) []pkix.AttributeTypeAndValueSET {
1825 var attributes []pkix.AttributeTypeAndValueSET
1826 for _, rawAttr := range rawAttributes {
1827 var attr pkix.AttributeTypeAndValueSET
1828 rest, err := asn1.Unmarshal(rawAttr.FullBytes, &attr)
1829 // Ignore attributes that don't parse into pkix.AttributeTypeAndValueSET
1830 // (i.e.: challengePassword or unstructuredName).
1831 if err == nil && len(rest) == 0 {
1832 attributes = append(attributes, attr)
1838 // parseCSRExtensions parses the attributes from a CSR and extracts any
1839 // requested extensions.
1840 func parseCSRExtensions(rawAttributes []asn1.RawValue) ([]pkix.Extension, error) {
1841 // pkcs10Attribute reflects the Attribute structure from RFC 2986, Section 4.1.
1842 type pkcs10Attribute struct {
1843 Id asn1.ObjectIdentifier
1844 Values []asn1.RawValue `asn1:"set"`
1847 var ret []pkix.Extension
1848 requestedExts := make(map[string]bool)
1849 for _, rawAttr := range rawAttributes {
1850 var attr pkcs10Attribute
1851 if rest, err := asn1.Unmarshal(rawAttr.FullBytes, &attr); err != nil || len(rest) != 0 || len(attr.Values) == 0 {
1852 // Ignore attributes that don't parse.
1856 if !attr.Id.Equal(oidExtensionRequest) {
1860 var extensions []pkix.Extension
1861 if _, err := asn1.Unmarshal(attr.Values[0].FullBytes, &extensions); err != nil {
1864 for _, ext := range extensions {
1865 oidStr := ext.Id.String()
1866 if requestedExts[oidStr] {
1867 return nil, errors.New("x509: certificate request contains duplicate requested extensions")
1869 requestedExts[oidStr] = true
1871 ret = append(ret, extensions...)
1877 // CreateCertificateRequest creates a new certificate request based on a
1878 // template. The following members of template are used:
1880 // - SignatureAlgorithm
1886 // - ExtraExtensions
1887 // - Attributes (deprecated)
1889 // priv is the private key to sign the CSR with, and the corresponding public
1890 // key will be included in the CSR. It must implement crypto.Signer and its
1891 // Public() method must return a *rsa.PublicKey or a *ecdsa.PublicKey or a
1892 // ed25519.PublicKey. (A *rsa.PrivateKey, *ecdsa.PrivateKey or
1893 // ed25519.PrivateKey satisfies this.)
1895 // The returned slice is the certificate request in DER encoding.
1896 func CreateCertificateRequest(rand io.Reader, template *CertificateRequest, priv any) (csr []byte, err error) {
1897 key, ok := priv.(crypto.Signer)
1899 return nil, errors.New("x509: certificate private key does not implement crypto.Signer")
1902 var hashFunc crypto.Hash
1903 var sigAlgo pkix.AlgorithmIdentifier
1904 hashFunc, sigAlgo, err = signingParamsForPublicKey(key.Public(), template.SignatureAlgorithm)
1909 var publicKeyBytes []byte
1910 var publicKeyAlgorithm pkix.AlgorithmIdentifier
1911 publicKeyBytes, publicKeyAlgorithm, err = marshalPublicKey(key.Public())
1916 extensions, err := buildCSRExtensions(template)
1921 // Make a copy of template.Attributes because we may alter it below.
1922 attributes := make([]pkix.AttributeTypeAndValueSET, 0, len(template.Attributes))
1923 for _, attr := range template.Attributes {
1924 values := make([][]pkix.AttributeTypeAndValue, len(attr.Value))
1925 copy(values, attr.Value)
1926 attributes = append(attributes, pkix.AttributeTypeAndValueSET{
1932 extensionsAppended := false
1933 if len(extensions) > 0 {
1934 // Append the extensions to an existing attribute if possible.
1935 for _, atvSet := range attributes {
1936 if !atvSet.Type.Equal(oidExtensionRequest) || len(atvSet.Value) == 0 {
1940 // specifiedExtensions contains all the extensions that we
1941 // found specified via template.Attributes.
1942 specifiedExtensions := make(map[string]bool)
1944 for _, atvs := range atvSet.Value {
1945 for _, atv := range atvs {
1946 specifiedExtensions[atv.Type.String()] = true
1950 newValue := make([]pkix.AttributeTypeAndValue, 0, len(atvSet.Value[0])+len(extensions))
1951 newValue = append(newValue, atvSet.Value[0]...)
1953 for _, e := range extensions {
1954 if specifiedExtensions[e.Id.String()] {
1955 // Attributes already contained a value for
1956 // this extension and it takes priority.
1960 newValue = append(newValue, pkix.AttributeTypeAndValue{
1961 // There is no place for the critical
1962 // flag in an AttributeTypeAndValue.
1968 atvSet.Value[0] = newValue
1969 extensionsAppended = true
1974 rawAttributes, err := newRawAttributes(attributes)
1979 // If not included in attributes, add a new attribute for the
1981 if len(extensions) > 0 && !extensionsAppended {
1983 Type asn1.ObjectIdentifier
1984 Value [][]pkix.Extension `asn1:"set"`
1986 Type: oidExtensionRequest,
1987 Value: [][]pkix.Extension{extensions},
1990 b, err := asn1.Marshal(attr)
1992 return nil, errors.New("x509: failed to serialise extensions attribute: " + err.Error())
1995 var rawValue asn1.RawValue
1996 if _, err := asn1.Unmarshal(b, &rawValue); err != nil {
2000 rawAttributes = append(rawAttributes, rawValue)
2003 asn1Subject := template.RawSubject
2004 if len(asn1Subject) == 0 {
2005 asn1Subject, err = asn1.Marshal(template.Subject.ToRDNSequence())
2011 tbsCSR := tbsCertificateRequest{
2012 Version: 0, // PKCS #10, RFC 2986
2013 Subject: asn1.RawValue{FullBytes: asn1Subject},
2014 PublicKey: publicKeyInfo{
2015 Algorithm: publicKeyAlgorithm,
2016 PublicKey: asn1.BitString{
2017 Bytes: publicKeyBytes,
2018 BitLength: len(publicKeyBytes) * 8,
2021 RawAttributes: rawAttributes,
2024 tbsCSRContents, err := asn1.Marshal(tbsCSR)
2028 tbsCSR.Raw = tbsCSRContents
2030 signed := tbsCSRContents
2037 var signature []byte
2038 signature, err = key.Sign(rand, signed, hashFunc)
2043 return asn1.Marshal(certificateRequest{
2045 SignatureAlgorithm: sigAlgo,
2046 SignatureValue: asn1.BitString{
2048 BitLength: len(signature) * 8,
2053 // ParseCertificateRequest parses a single certificate request from the
2054 // given ASN.1 DER data.
2055 func ParseCertificateRequest(asn1Data []byte) (*CertificateRequest, error) {
2056 var csr certificateRequest
2058 rest, err := asn1.Unmarshal(asn1Data, &csr)
2061 } else if len(rest) != 0 {
2062 return nil, asn1.SyntaxError{Msg: "trailing data"}
2065 return parseCertificateRequest(&csr)
2068 func parseCertificateRequest(in *certificateRequest) (*CertificateRequest, error) {
2069 out := &CertificateRequest{
2071 RawTBSCertificateRequest: in.TBSCSR.Raw,
2072 RawSubjectPublicKeyInfo: in.TBSCSR.PublicKey.Raw,
2073 RawSubject: in.TBSCSR.Subject.FullBytes,
2075 Signature: in.SignatureValue.RightAlign(),
2076 SignatureAlgorithm: getSignatureAlgorithmFromAI(in.SignatureAlgorithm),
2078 PublicKeyAlgorithm: getPublicKeyAlgorithmFromOID(in.TBSCSR.PublicKey.Algorithm.Algorithm),
2080 Version: in.TBSCSR.Version,
2081 Attributes: parseRawAttributes(in.TBSCSR.RawAttributes),
2085 if out.PublicKeyAlgorithm != UnknownPublicKeyAlgorithm {
2086 out.PublicKey, err = parsePublicKey(&in.TBSCSR.PublicKey)
2092 var subject pkix.RDNSequence
2093 if rest, err := asn1.Unmarshal(in.TBSCSR.Subject.FullBytes, &subject); err != nil {
2095 } else if len(rest) != 0 {
2096 return nil, errors.New("x509: trailing data after X.509 Subject")
2099 out.Subject.FillFromRDNSequence(&subject)
2101 if out.Extensions, err = parseCSRExtensions(in.TBSCSR.RawAttributes); err != nil {
2105 for _, extension := range out.Extensions {
2107 case extension.Id.Equal(oidExtensionSubjectAltName):
2108 out.DNSNames, out.EmailAddresses, out.IPAddresses, out.URIs, err = parseSANExtension(extension.Value)
2118 // CheckSignature reports whether the signature on c is valid.
2119 func (c *CertificateRequest) CheckSignature() error {
2120 return checkSignature(c.SignatureAlgorithm, c.RawTBSCertificateRequest, c.Signature, c.PublicKey, true)
2123 // RevocationList contains the fields used to create an X.509 v2 Certificate
2124 // Revocation list with CreateRevocationList.
2125 type RevocationList struct {
2126 // Raw contains the complete ASN.1 DER content of the CRL (tbsCertList,
2127 // signatureAlgorithm, and signatureValue.)
2129 // RawTBSRevocationList contains just the tbsCertList portion of the ASN.1
2131 RawTBSRevocationList []byte
2132 // RawIssuer contains the DER encoded Issuer.
2135 // Issuer contains the DN of the issuing certificate.
2137 // AuthorityKeyId is used to identify the public key associated with the
2138 // issuing certificate. It is populated from the authorityKeyIdentifier
2139 // extension when parsing a CRL. It is ignored when creating a CRL; the
2140 // extension is populated from the issuing certificate itself.
2141 AuthorityKeyId []byte
2144 // SignatureAlgorithm is used to determine the signature algorithm to be
2145 // used when signing the CRL. If 0 the default algorithm for the signing
2146 // key will be used.
2147 SignatureAlgorithm SignatureAlgorithm
2149 // RevokedCertificates is used to populate the revokedCertificates
2150 // sequence in the CRL, it may be empty. RevokedCertificates may be nil,
2151 // in which case an empty CRL will be created.
2152 RevokedCertificates []pkix.RevokedCertificate
2154 // Number is used to populate the X.509 v2 cRLNumber extension in the CRL,
2155 // which should be a monotonically increasing sequence number for a given
2156 // CRL scope and CRL issuer. It is also populated from the cRLNumber
2157 // extension when parsing a CRL.
2160 // ThisUpdate is used to populate the thisUpdate field in the CRL, which
2161 // indicates the issuance date of the CRL.
2162 ThisUpdate time.Time
2163 // NextUpdate is used to populate the nextUpdate field in the CRL, which
2164 // indicates the date by which the next CRL will be issued. NextUpdate
2165 // must be greater than ThisUpdate.
2166 NextUpdate time.Time
2168 // Extensions contains raw X.509 extensions. When creating a CRL,
2169 // the Extensions field is ignored, see ExtraExtensions.
2170 Extensions []pkix.Extension
2172 // ExtraExtensions contains any additional extensions to add directly to
2174 ExtraExtensions []pkix.Extension
2177 // These structures reflect the ASN.1 structure of X.509 CRLs better than
2178 // the existing crypto/x509/pkix variants do. These mirror the existing
2179 // certificate structs in this file.
2181 // Notably, we include issuer as an asn1.RawValue, mirroring the behavior of
2182 // tbsCertificate and allowing raw (unparsed) subjects to be passed cleanly.
2183 type certificateList struct {
2184 TBSCertList tbsCertificateList
2185 SignatureAlgorithm pkix.AlgorithmIdentifier
2186 SignatureValue asn1.BitString
2189 type tbsCertificateList struct {
2191 Version int `asn1:"optional,default:0"`
2192 Signature pkix.AlgorithmIdentifier
2193 Issuer asn1.RawValue
2194 ThisUpdate time.Time
2195 NextUpdate time.Time `asn1:"optional"`
2196 RevokedCertificates []pkix.RevokedCertificate `asn1:"optional"`
2197 Extensions []pkix.Extension `asn1:"tag:0,optional,explicit"`
2200 // CreateRevocationList creates a new X.509 v2 Certificate Revocation List,
2201 // according to RFC 5280, based on template.
2203 // The CRL is signed by priv which should be the private key associated with
2204 // the public key in the issuer certificate.
2206 // The issuer may not be nil, and the crlSign bit must be set in KeyUsage in
2207 // order to use it as a CRL issuer.
2209 // The issuer distinguished name CRL field and authority key identifier
2210 // extension are populated using the issuer certificate. issuer must have
2211 // SubjectKeyId set.
2212 func CreateRevocationList(rand io.Reader, template *RevocationList, issuer *Certificate, priv crypto.Signer) ([]byte, error) {
2213 if template == nil {
2214 return nil, errors.New("x509: template can not be nil")
2217 return nil, errors.New("x509: issuer can not be nil")
2219 if (issuer.KeyUsage & KeyUsageCRLSign) == 0 {
2220 return nil, errors.New("x509: issuer must have the crlSign key usage bit set")
2222 if len(issuer.SubjectKeyId) == 0 {
2223 return nil, errors.New("x509: issuer certificate doesn't contain a subject key identifier")
2225 if template.NextUpdate.Before(template.ThisUpdate) {
2226 return nil, errors.New("x509: template.ThisUpdate is after template.NextUpdate")
2228 if template.Number == nil {
2229 return nil, errors.New("x509: template contains nil Number field")
2232 hashFunc, signatureAlgorithm, err := signingParamsForPublicKey(priv.Public(), template.SignatureAlgorithm)
2237 // Force revocation times to UTC per RFC 5280.
2238 revokedCertsUTC := make([]pkix.RevokedCertificate, len(template.RevokedCertificates))
2239 for i, rc := range template.RevokedCertificates {
2240 rc.RevocationTime = rc.RevocationTime.UTC()
2241 revokedCertsUTC[i] = rc
2244 aki, err := asn1.Marshal(authKeyId{Id: issuer.SubjectKeyId})
2249 if numBytes := template.Number.Bytes(); len(numBytes) > 20 || (len(numBytes) == 20 && numBytes[0]&0x80 != 0) {
2250 return nil, errors.New("x509: CRL number exceeds 20 octets")
2252 crlNum, err := asn1.Marshal(template.Number)
2257 // Correctly use the issuer's subject sequence if one is specified.
2258 issuerSubject, err := subjectBytes(issuer)
2263 tbsCertList := tbsCertificateList{
2265 Signature: signatureAlgorithm,
2266 Issuer: asn1.RawValue{FullBytes: issuerSubject},
2267 ThisUpdate: template.ThisUpdate.UTC(),
2268 NextUpdate: template.NextUpdate.UTC(),
2269 Extensions: []pkix.Extension{
2271 Id: oidExtensionAuthorityKeyId,
2275 Id: oidExtensionCRLNumber,
2280 if len(revokedCertsUTC) > 0 {
2281 tbsCertList.RevokedCertificates = revokedCertsUTC
2284 if len(template.ExtraExtensions) > 0 {
2285 tbsCertList.Extensions = append(tbsCertList.Extensions, template.ExtraExtensions...)
2288 tbsCertListContents, err := asn1.Marshal(tbsCertList)
2293 // Optimization to only marshal this struct once, when signing and
2294 // then embedding in certificateList below.
2295 tbsCertList.Raw = tbsCertListContents
2297 input := tbsCertListContents
2300 h.Write(tbsCertListContents)
2303 var signerOpts crypto.SignerOpts = hashFunc
2304 if template.SignatureAlgorithm.isRSAPSS() {
2305 signerOpts = &rsa.PSSOptions{
2306 SaltLength: rsa.PSSSaltLengthEqualsHash,
2311 signature, err := priv.Sign(rand, input, signerOpts)
2316 return asn1.Marshal(certificateList{
2317 TBSCertList: tbsCertList,
2318 SignatureAlgorithm: signatureAlgorithm,
2319 SignatureValue: asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
2323 // CheckSignatureFrom verifies that the signature on rl is a valid signature
2325 func (rl *RevocationList) CheckSignatureFrom(parent *Certificate) error {
2326 if parent.Version == 3 && !parent.BasicConstraintsValid ||
2327 parent.BasicConstraintsValid && !parent.IsCA {
2328 return ConstraintViolationError{}
2331 if parent.KeyUsage != 0 && parent.KeyUsage&KeyUsageCRLSign == 0 {
2332 return ConstraintViolationError{}
2335 if parent.PublicKeyAlgorithm == UnknownPublicKeyAlgorithm {
2336 return ErrUnsupportedAlgorithm
2339 return parent.CheckSignature(rl.SignatureAlgorithm, rl.RawTBSRevocationList, rl.Signature)