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-rw-r--r--src/pkg/crypto/x509/x509.go1073
1 files changed, 1073 insertions, 0 deletions
diff --git a/src/pkg/crypto/x509/x509.go b/src/pkg/crypto/x509/x509.go
new file mode 100644
index 000000000..8fda47159
--- /dev/null
+++ b/src/pkg/crypto/x509/x509.go
@@ -0,0 +1,1073 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package x509 parses X.509-encoded keys and certificates.
+package x509
+
+import (
+ "asn1"
+ "big"
+ "bytes"
+ "crypto"
+ "crypto/dsa"
+ "crypto/rsa"
+ "crypto/sha1"
+ "crypto/x509/pkix"
+ "encoding/pem"
+ "io"
+ "os"
+ "time"
+)
+
+// pkcs1PrivateKey is a structure which mirrors the PKCS#1 ASN.1 for an RSA private key.
+type pkcs1PrivateKey struct {
+ Version int
+ N *big.Int
+ E int
+ D *big.Int
+ P *big.Int
+ Q *big.Int
+ // We ignore these values, if present, because rsa will calculate them.
+ Dp *big.Int `asn1:"optional"`
+ Dq *big.Int `asn1:"optional"`
+ Qinv *big.Int `asn1:"optional"`
+
+ AdditionalPrimes []pkcs1AdditionalRSAPrime `asn1:"optional"`
+}
+
+type pkcs1AdditionalRSAPrime struct {
+ Prime *big.Int
+
+ // We ignore these values because rsa will calculate them.
+ Exp *big.Int
+ Coeff *big.Int
+}
+
+// ParsePKCS1PrivateKey returns an RSA private key from its ASN.1 PKCS#1 DER encoded form.
+func ParsePKCS1PrivateKey(der []byte) (key *rsa.PrivateKey, err os.Error) {
+ var priv pkcs1PrivateKey
+ rest, err := asn1.Unmarshal(der, &priv)
+ if len(rest) > 0 {
+ err = asn1.SyntaxError{"trailing data"}
+ return
+ }
+ if err != nil {
+ return
+ }
+
+ if priv.Version > 1 {
+ return nil, os.NewError("x509: unsupported private key version")
+ }
+
+ if priv.N.Sign() <= 0 || priv.D.Sign() <= 0 || priv.P.Sign() <= 0 || priv.Q.Sign() <= 0 {
+ return nil, os.NewError("private key contains zero or negative value")
+ }
+
+ key = new(rsa.PrivateKey)
+ key.PublicKey = rsa.PublicKey{
+ E: priv.E,
+ N: priv.N,
+ }
+
+ key.D = priv.D
+ key.Primes = make([]*big.Int, 2+len(priv.AdditionalPrimes))
+ key.Primes[0] = priv.P
+ key.Primes[1] = priv.Q
+ for i, a := range priv.AdditionalPrimes {
+ if a.Prime.Sign() <= 0 {
+ return nil, os.NewError("private key contains zero or negative prime")
+ }
+ key.Primes[i+2] = a.Prime
+ // We ignore the other two values because rsa will calculate
+ // them as needed.
+ }
+
+ err = key.Validate()
+ if err != nil {
+ return nil, err
+ }
+ key.Precompute()
+
+ return
+}
+
+// MarshalPKCS1PrivateKey converts a private key to ASN.1 DER encoded form.
+func MarshalPKCS1PrivateKey(key *rsa.PrivateKey) []byte {
+ key.Precompute()
+
+ version := 0
+ if len(key.Primes) > 2 {
+ version = 1
+ }
+
+ priv := pkcs1PrivateKey{
+ Version: version,
+ N: key.N,
+ E: key.PublicKey.E,
+ D: key.D,
+ P: key.Primes[0],
+ Q: key.Primes[1],
+ Dp: key.Precomputed.Dp,
+ Dq: key.Precomputed.Dq,
+ Qinv: key.Precomputed.Qinv,
+ }
+
+ priv.AdditionalPrimes = make([]pkcs1AdditionalRSAPrime, len(key.Precomputed.CRTValues))
+ for i, values := range key.Precomputed.CRTValues {
+ priv.AdditionalPrimes[i].Prime = key.Primes[2+i]
+ priv.AdditionalPrimes[i].Exp = values.Exp
+ priv.AdditionalPrimes[i].Coeff = values.Coeff
+ }
+
+ b, _ := asn1.Marshal(priv)
+ return b
+}
+
+// These structures reflect the ASN.1 structure of X.509 certificates.:
+
+type certificate struct {
+ Raw asn1.RawContent
+ TBSCertificate tbsCertificate
+ SignatureAlgorithm pkix.AlgorithmIdentifier
+ SignatureValue asn1.BitString
+}
+
+type tbsCertificate struct {
+ Raw asn1.RawContent
+ Version int `asn1:"optional,explicit,default:1,tag:0"`
+ SerialNumber *big.Int
+ SignatureAlgorithm pkix.AlgorithmIdentifier
+ Issuer pkix.RDNSequence
+ Validity validity
+ Subject pkix.RDNSequence
+ PublicKey publicKeyInfo
+ UniqueId asn1.BitString `asn1:"optional,tag:1"`
+ SubjectUniqueId asn1.BitString `asn1:"optional,tag:2"`
+ Extensions []pkix.Extension `asn1:"optional,explicit,tag:3"`
+}
+
+type dsaAlgorithmParameters struct {
+ P, Q, G *big.Int
+}
+
+type dsaSignature struct {
+ R, S *big.Int
+}
+
+type validity struct {
+ NotBefore, NotAfter *time.Time
+}
+
+type publicKeyInfo struct {
+ Raw asn1.RawContent
+ Algorithm pkix.AlgorithmIdentifier
+ PublicKey asn1.BitString
+}
+
+// RFC 5280, 4.2.1.1
+type authKeyId struct {
+ Id []byte `asn1:"optional,tag:0"`
+}
+
+type SignatureAlgorithm int
+
+const (
+ UnknownSignatureAlgorithm SignatureAlgorithm = iota
+ MD2WithRSA
+ MD5WithRSA
+ SHA1WithRSA
+ SHA256WithRSA
+ SHA384WithRSA
+ SHA512WithRSA
+ DSAWithSHA1
+ DSAWithSHA256
+)
+
+type PublicKeyAlgorithm int
+
+const (
+ UnknownPublicKeyAlgorithm PublicKeyAlgorithm = iota
+ RSA
+ DSA
+)
+
+// OIDs for signature algorithms
+//
+// pkcs-1 OBJECT IDENTIFIER ::= {
+// iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 1 }
+//
+//
+// RFC 3279 2.2.1 RSA Signature Algorithms
+//
+// md2WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 2 }
+//
+// md5WithRSAEncryption OBJECT IDENTIFER ::= { pkcs-1 4 }
+//
+// sha-1WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 5 }
+//
+// dsaWithSha1 OBJECT IDENTIFIER ::= {
+// iso(1) member-body(2) us(840) x9-57(10040) x9cm(4) 3 }
+//
+//
+// RFC 4055 5 PKCS #1 Version 1.5
+//
+// sha256WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 11 }
+//
+// sha384WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 12 }
+//
+// sha512WithRSAEncryption OBJECT IDENTIFIER ::= { pkcs-1 13 }
+//
+//
+// RFC 5758 3.1 DSA Signature Algorithms
+//
+// dsaWithSha356 OBJECT IDENTIFER ::= {
+// joint-iso-ccitt(2) country(16) us(840) organization(1) gov(101)
+// algorithms(4) id-dsa-with-sha2(3) 2}
+//
+var (
+ oidSignatureMD2WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 2}
+ oidSignatureMD5WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 4}
+ oidSignatureSHA1WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 5}
+ oidSignatureSHA256WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 11}
+ oidSignatureSHA384WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 12}
+ oidSignatureSHA512WithRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 13}
+ oidSignatureDSAWithSHA1 = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 3}
+ oidSignatureDSAWithSHA256 = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 4, 3, 2}
+)
+
+func getSignatureAlgorithmFromOID(oid asn1.ObjectIdentifier) SignatureAlgorithm {
+ switch {
+ case oid.Equal(oidSignatureMD2WithRSA):
+ return MD2WithRSA
+ case oid.Equal(oidSignatureMD5WithRSA):
+ return MD5WithRSA
+ case oid.Equal(oidSignatureSHA1WithRSA):
+ return SHA1WithRSA
+ case oid.Equal(oidSignatureSHA256WithRSA):
+ return SHA256WithRSA
+ case oid.Equal(oidSignatureSHA384WithRSA):
+ return SHA384WithRSA
+ case oid.Equal(oidSignatureSHA512WithRSA):
+ return SHA512WithRSA
+ case oid.Equal(oidSignatureDSAWithSHA1):
+ return DSAWithSHA1
+ case oid.Equal(oidSignatureDSAWithSHA256):
+ return DSAWithSHA256
+ }
+ return UnknownSignatureAlgorithm
+}
+
+// RFC 3279, 2.3 Public Key Algorithms
+//
+// pkcs-1 OBJECT IDENTIFIER ::== { iso(1) member-body(2) us(840)
+// rsadsi(113549) pkcs(1) 1 }
+//
+// rsaEncryption OBJECT IDENTIFIER ::== { pkcs1-1 1 }
+//
+// id-dsa OBJECT IDENTIFIER ::== { iso(1) member-body(2) us(840)
+// x9-57(10040) x9cm(4) 1 }
+var (
+ oidPublicKeyRsa = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 1}
+ oidPublicKeyDsa = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 1}
+)
+
+func getPublicKeyAlgorithmFromOID(oid asn1.ObjectIdentifier) PublicKeyAlgorithm {
+ switch {
+ case oid.Equal(oidPublicKeyRsa):
+ return RSA
+ case oid.Equal(oidPublicKeyDsa):
+ return DSA
+ }
+ return UnknownPublicKeyAlgorithm
+}
+
+// KeyUsage represents the set of actions that are valid for a given key. It's
+// a bitmap of the KeyUsage* constants.
+type KeyUsage int
+
+const (
+ KeyUsageDigitalSignature KeyUsage = 1 << iota
+ KeyUsageContentCommitment
+ KeyUsageKeyEncipherment
+ KeyUsageDataEncipherment
+ KeyUsageKeyAgreement
+ KeyUsageCertSign
+ KeyUsageCRLSign
+ KeyUsageEncipherOnly
+ KeyUsageDecipherOnly
+)
+
+// RFC 5280, 4.2.1.12 Extended Key Usage
+//
+// anyExtendedKeyUsage OBJECT IDENTIFIER ::= { id-ce-extKeyUsage 0 }
+//
+// id-kp OBJECT IDENTIFIER ::= { id-pkix 3 }
+//
+// id-kp-serverAuth OBJECT IDENTIFIER ::= { id-kp 1 }
+// id-kp-clientAuth OBJECT IDENTIFIER ::= { id-kp 2 }
+// id-kp-codeSigning OBJECT IDENTIFIER ::= { id-kp 3 }
+// id-kp-emailProtection OBJECT IDENTIFIER ::= { id-kp 4 }
+// id-kp-timeStamping OBJECT IDENTIFIER ::= { id-kp 8 }
+// id-kp-OCSPSigning OBJECT IDENTIFIER ::= { id-kp 9 }
+var (
+ oidExtKeyUsageAny = asn1.ObjectIdentifier{2, 5, 29, 37, 0}
+ oidExtKeyUsageServerAuth = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 1}
+ oidExtKeyUsageClientAuth = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 2}
+ oidExtKeyUsageCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 3}
+ oidExtKeyUsageEmailProtection = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 4}
+ oidExtKeyUsageTimeStamping = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 8}
+ oidExtKeyUsageOCSPSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 9}
+)
+
+// ExtKeyUsage represents an extended set of actions that are valid for a given key.
+// Each of the ExtKeyUsage* constants define a unique action.
+type ExtKeyUsage int
+
+const (
+ ExtKeyUsageAny ExtKeyUsage = iota
+ ExtKeyUsageServerAuth
+ ExtKeyUsageClientAuth
+ ExtKeyUsageCodeSigning
+ ExtKeyUsageEmailProtection
+ ExtKeyUsageTimeStamping
+ ExtKeyUsageOCSPSigning
+)
+
+// A Certificate represents an X.509 certificate.
+type Certificate struct {
+ Raw []byte // Complete ASN.1 DER content (certificate, signature algorithm and signature).
+ RawTBSCertificate []byte // Certificate part of raw ASN.1 DER content.
+ RawSubjectPublicKeyInfo []byte // DER encoded SubjectPublicKeyInfo.
+
+ Signature []byte
+ SignatureAlgorithm SignatureAlgorithm
+
+ PublicKeyAlgorithm PublicKeyAlgorithm
+ PublicKey interface{}
+
+ Version int
+ SerialNumber *big.Int
+ Issuer pkix.Name
+ Subject pkix.Name
+ NotBefore, NotAfter *time.Time // Validity bounds.
+ KeyUsage KeyUsage
+
+ ExtKeyUsage []ExtKeyUsage // Sequence of extended key usages.
+ UnknownExtKeyUsage []asn1.ObjectIdentifier // Encountered extended key usages unknown to this package.
+
+ BasicConstraintsValid bool // if true then the next two fields are valid.
+ IsCA bool
+ MaxPathLen int
+
+ SubjectKeyId []byte
+ AuthorityKeyId []byte
+
+ // Subject Alternate Name values
+ DNSNames []string
+ EmailAddresses []string
+
+ // Name constraints
+ PermittedDNSDomainsCritical bool // if true then the name constraints are marked critical.
+ PermittedDNSDomains []string
+
+ PolicyIdentifiers []asn1.ObjectIdentifier
+}
+
+// UnsupportedAlgorithmError results from attempting to perform an operation
+// that involves algorithms that are not currently implemented.
+type UnsupportedAlgorithmError struct{}
+
+func (UnsupportedAlgorithmError) String() string {
+ return "cannot verify signature: algorithm unimplemented"
+}
+
+// ConstraintViolationError results when a requested usage is not permitted by
+// a certificate. For example: checking a signature when the public key isn't a
+// certificate signing key.
+type ConstraintViolationError struct{}
+
+func (ConstraintViolationError) String() string {
+ return "invalid signature: parent certificate cannot sign this kind of certificate"
+}
+
+func (c *Certificate) Equal(other *Certificate) bool {
+ return bytes.Equal(c.Raw, other.Raw)
+}
+
+// CheckSignatureFrom verifies that the signature on c is a valid signature
+// from parent.
+func (c *Certificate) CheckSignatureFrom(parent *Certificate) (err os.Error) {
+ // RFC 5280, 4.2.1.9:
+ // "If the basic constraints extension is not present in a version 3
+ // certificate, or the extension is present but the cA boolean is not
+ // asserted, then the certified public key MUST NOT be used to verify
+ // certificate signatures."
+ if parent.Version == 3 && !parent.BasicConstraintsValid ||
+ parent.BasicConstraintsValid && !parent.IsCA {
+ return ConstraintViolationError{}
+ }
+
+ if parent.KeyUsage != 0 && parent.KeyUsage&KeyUsageCertSign == 0 {
+ return ConstraintViolationError{}
+ }
+
+ if parent.PublicKeyAlgorithm == UnknownPublicKeyAlgorithm {
+ return UnsupportedAlgorithmError{}
+ }
+
+ // TODO(agl): don't ignore the path length constraint.
+
+ return parent.CheckSignature(c.SignatureAlgorithm, c.RawTBSCertificate, c.Signature)
+}
+
+// CheckSignature verifies that signature is a valid signature over signed from
+// c's public key.
+func (c *Certificate) CheckSignature(algo SignatureAlgorithm, signed, signature []byte) (err os.Error) {
+ var hashType crypto.Hash
+
+ switch algo {
+ case SHA1WithRSA, DSAWithSHA1:
+ hashType = crypto.SHA1
+ case SHA256WithRSA, DSAWithSHA256:
+ hashType = crypto.SHA256
+ case SHA384WithRSA:
+ hashType = crypto.SHA384
+ case SHA512WithRSA:
+ hashType = crypto.SHA512
+ default:
+ return UnsupportedAlgorithmError{}
+ }
+
+ h := hashType.New()
+ if h == nil {
+ return UnsupportedAlgorithmError{}
+ }
+
+ h.Write(signed)
+ digest := h.Sum()
+
+ switch pub := c.PublicKey.(type) {
+ case *rsa.PublicKey:
+ return rsa.VerifyPKCS1v15(pub, hashType, digest, signature)
+ case *dsa.PublicKey:
+ dsaSig := new(dsaSignature)
+ if _, err := asn1.Unmarshal(signature, dsaSig); err != nil {
+ return err
+ }
+ if dsaSig.R.Sign() <= 0 || dsaSig.S.Sign() <= 0 {
+ return os.NewError("DSA signature contained zero or negative values")
+ }
+ if !dsa.Verify(pub, digest, dsaSig.R, dsaSig.S) {
+ return os.NewError("DSA verification failure")
+ }
+ return
+ }
+ return UnsupportedAlgorithmError{}
+}
+
+// CheckCRLSignature checks that the signature in crl is from c.
+func (c *Certificate) CheckCRLSignature(crl *pkix.CertificateList) (err os.Error) {
+ algo := getSignatureAlgorithmFromOID(crl.SignatureAlgorithm.Algorithm)
+ return c.CheckSignature(algo, crl.TBSCertList.Raw, crl.SignatureValue.RightAlign())
+}
+
+type UnhandledCriticalExtension struct{}
+
+func (h UnhandledCriticalExtension) String() string {
+ return "unhandled critical extension"
+}
+
+type basicConstraints struct {
+ IsCA bool `asn1:"optional"`
+ MaxPathLen int `asn1:"optional"`
+}
+
+type rsaPublicKey struct {
+ N *big.Int
+ E int
+}
+
+// RFC 5280 4.2.1.4
+type policyInformation struct {
+ Policy asn1.ObjectIdentifier
+ // policyQualifiers omitted
+}
+
+// RFC 5280, 4.2.1.10
+type nameConstraints struct {
+ Permitted []generalSubtree `asn1:"optional,tag:0"`
+ Excluded []generalSubtree `asn1:"optional,tag:1"`
+}
+
+type generalSubtree struct {
+ Name string `asn1:"tag:2,optional,ia5"`
+ Min int `asn1:"optional,tag:0"`
+ Max int `asn1:"optional,tag:1"`
+}
+
+func parsePublicKey(algo PublicKeyAlgorithm, keyData *publicKeyInfo) (interface{}, os.Error) {
+ asn1Data := keyData.PublicKey.RightAlign()
+ switch algo {
+ case RSA:
+ p := new(rsaPublicKey)
+ _, err := asn1.Unmarshal(asn1Data, p)
+ if err != nil {
+ return nil, err
+ }
+
+ pub := &rsa.PublicKey{
+ E: p.E,
+ N: p.N,
+ }
+ return pub, nil
+ case DSA:
+ var p *big.Int
+ _, err := asn1.Unmarshal(asn1Data, &p)
+ if err != nil {
+ return nil, err
+ }
+ paramsData := keyData.Algorithm.Parameters.FullBytes
+ params := new(dsaAlgorithmParameters)
+ _, err = asn1.Unmarshal(paramsData, params)
+ if err != nil {
+ return nil, err
+ }
+ if p.Sign() <= 0 || params.P.Sign() <= 0 || params.Q.Sign() <= 0 || params.G.Sign() <= 0 {
+ return nil, os.NewError("zero or negative DSA parameter")
+ }
+ pub := &dsa.PublicKey{
+ Parameters: dsa.Parameters{
+ P: params.P,
+ Q: params.Q,
+ G: params.G,
+ },
+ Y: p,
+ }
+ return pub, nil
+ default:
+ return nil, nil
+ }
+ panic("unreachable")
+}
+
+func parseCertificate(in *certificate) (*Certificate, os.Error) {
+ out := new(Certificate)
+ out.Raw = in.Raw
+ out.RawTBSCertificate = in.TBSCertificate.Raw
+ out.RawSubjectPublicKeyInfo = in.TBSCertificate.PublicKey.Raw
+
+ out.Signature = in.SignatureValue.RightAlign()
+ out.SignatureAlgorithm =
+ getSignatureAlgorithmFromOID(in.TBSCertificate.SignatureAlgorithm.Algorithm)
+
+ out.PublicKeyAlgorithm =
+ getPublicKeyAlgorithmFromOID(in.TBSCertificate.PublicKey.Algorithm.Algorithm)
+ var err os.Error
+ out.PublicKey, err = parsePublicKey(out.PublicKeyAlgorithm, &in.TBSCertificate.PublicKey)
+ if err != nil {
+ return nil, err
+ }
+
+ if in.TBSCertificate.SerialNumber.Sign() < 0 {
+ return nil, os.NewError("negative serial number")
+ }
+
+ out.Version = in.TBSCertificate.Version + 1
+ out.SerialNumber = in.TBSCertificate.SerialNumber
+ out.Issuer.FillFromRDNSequence(&in.TBSCertificate.Issuer)
+ out.Subject.FillFromRDNSequence(&in.TBSCertificate.Subject)
+ out.NotBefore = in.TBSCertificate.Validity.NotBefore
+ out.NotAfter = in.TBSCertificate.Validity.NotAfter
+
+ for _, e := range in.TBSCertificate.Extensions {
+ if len(e.Id) == 4 && e.Id[0] == 2 && e.Id[1] == 5 && e.Id[2] == 29 {
+ switch e.Id[3] {
+ case 15:
+ // RFC 5280, 4.2.1.3
+ var usageBits asn1.BitString
+ _, err := asn1.Unmarshal(e.Value, &usageBits)
+
+ if err == nil {
+ var usage int
+ for i := 0; i < 9; i++ {
+ if usageBits.At(i) != 0 {
+ usage |= 1 << uint(i)
+ }
+ }
+ out.KeyUsage = KeyUsage(usage)
+ continue
+ }
+ case 19:
+ // RFC 5280, 4.2.1.9
+ var constraints basicConstraints
+ _, err := asn1.Unmarshal(e.Value, &constraints)
+
+ if err == nil {
+ out.BasicConstraintsValid = true
+ out.IsCA = constraints.IsCA
+ out.MaxPathLen = constraints.MaxPathLen
+ continue
+ }
+ case 17:
+ // RFC 5280, 4.2.1.6
+
+ // SubjectAltName ::= GeneralNames
+ //
+ // GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
+ //
+ // GeneralName ::= CHOICE {
+ // otherName [0] OtherName,
+ // rfc822Name [1] IA5String,
+ // dNSName [2] IA5String,
+ // x400Address [3] ORAddress,
+ // directoryName [4] Name,
+ // ediPartyName [5] EDIPartyName,
+ // uniformResourceIdentifier [6] IA5String,
+ // iPAddress [7] OCTET STRING,
+ // registeredID [8] OBJECT IDENTIFIER }
+ var seq asn1.RawValue
+ _, err := asn1.Unmarshal(e.Value, &seq)
+ if err != nil {
+ return nil, err
+ }
+ if !seq.IsCompound || seq.Tag != 16 || seq.Class != 0 {
+ return nil, asn1.StructuralError{"bad SAN sequence"}
+ }
+
+ parsedName := false
+
+ rest := seq.Bytes
+ for len(rest) > 0 {
+ var v asn1.RawValue
+ rest, err = asn1.Unmarshal(rest, &v)
+ if err != nil {
+ return nil, err
+ }
+ switch v.Tag {
+ case 1:
+ out.EmailAddresses = append(out.EmailAddresses, string(v.Bytes))
+ parsedName = true
+ case 2:
+ out.DNSNames = append(out.DNSNames, string(v.Bytes))
+ parsedName = true
+ }
+ }
+
+ if parsedName {
+ continue
+ }
+ // If we didn't parse any of the names then we
+ // fall through to the critical check below.
+
+ case 30:
+ // RFC 5280, 4.2.1.10
+
+ // NameConstraints ::= SEQUENCE {
+ // permittedSubtrees [0] GeneralSubtrees OPTIONAL,
+ // excludedSubtrees [1] GeneralSubtrees OPTIONAL }
+ //
+ // GeneralSubtrees ::= SEQUENCE SIZE (1..MAX) OF GeneralSubtree
+ //
+ // GeneralSubtree ::= SEQUENCE {
+ // base GeneralName,
+ // minimum [0] BaseDistance DEFAULT 0,
+ // maximum [1] BaseDistance OPTIONAL }
+ //
+ // BaseDistance ::= INTEGER (0..MAX)
+
+ var constraints nameConstraints
+ _, err := asn1.Unmarshal(e.Value, &constraints)
+ if err != nil {
+ return nil, err
+ }
+
+ if len(constraints.Excluded) > 0 && e.Critical {
+ return out, UnhandledCriticalExtension{}
+ }
+
+ for _, subtree := range constraints.Permitted {
+ if subtree.Min > 0 || subtree.Max > 0 || len(subtree.Name) == 0 {
+ if e.Critical {
+ return out, UnhandledCriticalExtension{}
+ }
+ continue
+ }
+ out.PermittedDNSDomains = append(out.PermittedDNSDomains, subtree.Name)
+ }
+ continue
+
+ case 35:
+ // RFC 5280, 4.2.1.1
+ var a authKeyId
+ _, err = asn1.Unmarshal(e.Value, &a)
+ if err != nil {
+ return nil, err
+ }
+ out.AuthorityKeyId = a.Id
+ continue
+
+ case 37:
+ // RFC 5280, 4.2.1.12. Extended Key Usage
+
+ // id-ce-extKeyUsage OBJECT IDENTIFIER ::= { id-ce 37 }
+ //
+ // ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
+ //
+ // KeyPurposeId ::= OBJECT IDENTIFIER
+
+ var keyUsage []asn1.ObjectIdentifier
+ _, err = asn1.Unmarshal(e.Value, &keyUsage)
+ if err != nil {
+ return nil, err
+ }
+
+ for _, u := range keyUsage {
+ switch {
+ case u.Equal(oidExtKeyUsageAny):
+ out.ExtKeyUsage = append(out.ExtKeyUsage, ExtKeyUsageAny)
+ case u.Equal(oidExtKeyUsageServerAuth):
+ out.ExtKeyUsage = append(out.ExtKeyUsage, ExtKeyUsageServerAuth)
+ case u.Equal(oidExtKeyUsageClientAuth):
+ out.ExtKeyUsage = append(out.ExtKeyUsage, ExtKeyUsageClientAuth)
+ case u.Equal(oidExtKeyUsageCodeSigning):
+ out.ExtKeyUsage = append(out.ExtKeyUsage, ExtKeyUsageCodeSigning)
+ case u.Equal(oidExtKeyUsageEmailProtection):
+ out.ExtKeyUsage = append(out.ExtKeyUsage, ExtKeyUsageEmailProtection)
+ case u.Equal(oidExtKeyUsageTimeStamping):
+ out.ExtKeyUsage = append(out.ExtKeyUsage, ExtKeyUsageTimeStamping)
+ case u.Equal(oidExtKeyUsageOCSPSigning):
+ out.ExtKeyUsage = append(out.ExtKeyUsage, ExtKeyUsageOCSPSigning)
+ default:
+ out.UnknownExtKeyUsage = append(out.UnknownExtKeyUsage, u)
+ }
+ }
+
+ continue
+
+ case 14:
+ // RFC 5280, 4.2.1.2
+ var keyid []byte
+ _, err = asn1.Unmarshal(e.Value, &keyid)
+ if err != nil {
+ return nil, err
+ }
+ out.SubjectKeyId = keyid
+ continue
+
+ case 32:
+ // RFC 5280 4.2.1.4: Certificate Policies
+ var policies []policyInformation
+ if _, err = asn1.Unmarshal(e.Value, &policies); err != nil {
+ return nil, err
+ }
+ out.PolicyIdentifiers = make([]asn1.ObjectIdentifier, len(policies))
+ for i, policy := range policies {
+ out.PolicyIdentifiers[i] = policy.Policy
+ }
+ }
+ }
+
+ if e.Critical {
+ return out, UnhandledCriticalExtension{}
+ }
+ }
+
+ return out, nil
+}
+
+// ParseCertificate parses a single certificate from the given ASN.1 DER data.
+func ParseCertificate(asn1Data []byte) (*Certificate, os.Error) {
+ var cert certificate
+ rest, err := asn1.Unmarshal(asn1Data, &cert)
+ if err != nil {
+ return nil, err
+ }
+ if len(rest) > 0 {
+ return nil, asn1.SyntaxError{"trailing data"}
+ }
+
+ return parseCertificate(&cert)
+}
+
+// ParseCertificates parses one or more certificates from the given ASN.1 DER
+// data. The certificates must be concatenated with no intermediate padding.
+func ParseCertificates(asn1Data []byte) ([]*Certificate, os.Error) {
+ var v []*certificate
+
+ for len(asn1Data) > 0 {
+ cert := new(certificate)
+ var err os.Error
+ asn1Data, err = asn1.Unmarshal(asn1Data, cert)
+ if err != nil {
+ return nil, err
+ }
+ v = append(v, cert)
+ }
+
+ ret := make([]*Certificate, len(v))
+ for i, ci := range v {
+ cert, err := parseCertificate(ci)
+ if err != nil {
+ return nil, err
+ }
+ ret[i] = cert
+ }
+
+ return ret, nil
+}
+
+func reverseBitsInAByte(in byte) byte {
+ b1 := in>>4 | in<<4
+ b2 := b1>>2&0x33 | b1<<2&0xcc
+ b3 := b2>>1&0x55 | b2<<1&0xaa
+ return b3
+}
+
+var (
+ oidExtensionSubjectKeyId = []int{2, 5, 29, 14}
+ oidExtensionKeyUsage = []int{2, 5, 29, 15}
+ oidExtensionAuthorityKeyId = []int{2, 5, 29, 35}
+ oidExtensionBasicConstraints = []int{2, 5, 29, 19}
+ oidExtensionSubjectAltName = []int{2, 5, 29, 17}
+ oidExtensionCertificatePolicies = []int{2, 5, 29, 32}
+ oidExtensionNameConstraints = []int{2, 5, 29, 30}
+)
+
+func buildExtensions(template *Certificate) (ret []pkix.Extension, err os.Error) {
+ ret = make([]pkix.Extension, 7 /* maximum number of elements. */ )
+ n := 0
+
+ if template.KeyUsage != 0 {
+ ret[n].Id = oidExtensionKeyUsage
+ ret[n].Critical = true
+
+ var a [2]byte
+ a[0] = reverseBitsInAByte(byte(template.KeyUsage))
+ a[1] = reverseBitsInAByte(byte(template.KeyUsage >> 8))
+
+ l := 1
+ if a[1] != 0 {
+ l = 2
+ }
+
+ ret[n].Value, err = asn1.Marshal(asn1.BitString{Bytes: a[0:l], BitLength: l * 8})
+ if err != nil {
+ return
+ }
+ n++
+ }
+
+ if template.BasicConstraintsValid {
+ ret[n].Id = oidExtensionBasicConstraints
+ ret[n].Value, err = asn1.Marshal(basicConstraints{template.IsCA, template.MaxPathLen})
+ ret[n].Critical = true
+ if err != nil {
+ return
+ }
+ n++
+ }
+
+ if len(template.SubjectKeyId) > 0 {
+ ret[n].Id = oidExtensionSubjectKeyId
+ ret[n].Value, err = asn1.Marshal(template.SubjectKeyId)
+ if err != nil {
+ return
+ }
+ n++
+ }
+
+ if len(template.AuthorityKeyId) > 0 {
+ ret[n].Id = oidExtensionAuthorityKeyId
+ ret[n].Value, err = asn1.Marshal(authKeyId{template.AuthorityKeyId})
+ if err != nil {
+ return
+ }
+ n++
+ }
+
+ if len(template.DNSNames) > 0 {
+ ret[n].Id = oidExtensionSubjectAltName
+ rawValues := make([]asn1.RawValue, len(template.DNSNames))
+ for i, name := range template.DNSNames {
+ rawValues[i] = asn1.RawValue{Tag: 2, Class: 2, Bytes: []byte(name)}
+ }
+ ret[n].Value, err = asn1.Marshal(rawValues)
+ if err != nil {
+ return
+ }
+ n++
+ }
+
+ if len(template.PolicyIdentifiers) > 0 {
+ ret[n].Id = oidExtensionCertificatePolicies
+ policies := make([]policyInformation, len(template.PolicyIdentifiers))
+ for i, policy := range template.PolicyIdentifiers {
+ policies[i].Policy = policy
+ }
+ ret[n].Value, err = asn1.Marshal(policies)
+ if err != nil {
+ return
+ }
+ n++
+ }
+
+ if len(template.PermittedDNSDomains) > 0 {
+ ret[n].Id = oidExtensionNameConstraints
+ ret[n].Critical = template.PermittedDNSDomainsCritical
+
+ var out nameConstraints
+ out.Permitted = make([]generalSubtree, len(template.PermittedDNSDomains))
+ for i, permitted := range template.PermittedDNSDomains {
+ out.Permitted[i] = generalSubtree{Name: permitted}
+ }
+ ret[n].Value, err = asn1.Marshal(out)
+ if err != nil {
+ return
+ }
+ n++
+ }
+
+ // Adding another extension here? Remember to update the maximum number
+ // of elements in the make() at the top of the function.
+
+ return ret[0:n], nil
+}
+
+var (
+ oidSHA1WithRSA = []int{1, 2, 840, 113549, 1, 1, 5}
+ oidRSA = []int{1, 2, 840, 113549, 1, 1, 1}
+)
+
+// CreateSelfSignedCertificate creates a new certificate based on
+// a template. The following members of template are used: SerialNumber,
+// Subject, NotBefore, NotAfter, KeyUsage, BasicConstraintsValid, IsCA,
+// MaxPathLen, SubjectKeyId, DNSNames, PermittedDNSDomainsCritical,
+// PermittedDNSDomains.
+//
+// The certificate is signed by parent. If parent is equal to template then the
+// certificate is self-signed. The parameter pub is the public key of the
+// signee and priv is the private key of the signer.
+//
+// The returned slice is the certificate in DER encoding.
+func CreateCertificate(rand io.Reader, template, parent *Certificate, pub *rsa.PublicKey, priv *rsa.PrivateKey) (cert []byte, err os.Error) {
+ asn1PublicKey, err := asn1.Marshal(rsaPublicKey{
+ N: pub.N,
+ E: pub.E,
+ })
+ if err != nil {
+ return
+ }
+
+ if len(parent.SubjectKeyId) > 0 {
+ template.AuthorityKeyId = parent.SubjectKeyId
+ }
+
+ extensions, err := buildExtensions(template)
+ if err != nil {
+ return
+ }
+
+ encodedPublicKey := asn1.BitString{BitLength: len(asn1PublicKey) * 8, Bytes: asn1PublicKey}
+ c := tbsCertificate{
+ Version: 2,
+ SerialNumber: template.SerialNumber,
+ SignatureAlgorithm: pkix.AlgorithmIdentifier{Algorithm: oidSHA1WithRSA},
+ Issuer: parent.Subject.ToRDNSequence(),
+ Validity: validity{template.NotBefore, template.NotAfter},
+ Subject: template.Subject.ToRDNSequence(),
+ PublicKey: publicKeyInfo{nil, pkix.AlgorithmIdentifier{Algorithm: oidRSA}, encodedPublicKey},
+ Extensions: extensions,
+ }
+
+ tbsCertContents, err := asn1.Marshal(c)
+ if err != nil {
+ return
+ }
+
+ c.Raw = tbsCertContents
+
+ h := sha1.New()
+ h.Write(tbsCertContents)
+ digest := h.Sum()
+
+ signature, err := rsa.SignPKCS1v15(rand, priv, crypto.SHA1, digest)
+ if err != nil {
+ return
+ }
+
+ cert, err = asn1.Marshal(certificate{
+ nil,
+ c,
+ pkix.AlgorithmIdentifier{Algorithm: oidSHA1WithRSA},
+ asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
+ })
+ return
+}
+
+// pemCRLPrefix is the magic string that indicates that we have a PEM encoded
+// CRL.
+var pemCRLPrefix = []byte("-----BEGIN X509 CRL")
+// pemType is the type of a PEM encoded CRL.
+var pemType = "X509 CRL"
+
+// ParseCRL parses a CRL from the given bytes. It's often the case that PEM
+// encoded CRLs will appear where they should be DER encoded, so this function
+// will transparently handle PEM encoding as long as there isn't any leading
+// garbage.
+func ParseCRL(crlBytes []byte) (certList *pkix.CertificateList, err os.Error) {
+ if bytes.HasPrefix(crlBytes, pemCRLPrefix) {
+ block, _ := pem.Decode(crlBytes)
+ if block != nil && block.Type == pemType {
+ crlBytes = block.Bytes
+ }
+ }
+ return ParseDERCRL(crlBytes)
+}
+
+// ParseDERCRL parses a DER encoded CRL from the given bytes.
+func ParseDERCRL(derBytes []byte) (certList *pkix.CertificateList, err os.Error) {
+ certList = new(pkix.CertificateList)
+ _, err = asn1.Unmarshal(derBytes, certList)
+ if err != nil {
+ certList = nil
+ }
+ return
+}
+
+// CreateCRL returns a DER encoded CRL, signed by this Certificate, that
+// contains the given list of revoked certificates.
+func (c *Certificate) CreateCRL(rand io.Reader, priv *rsa.PrivateKey, revokedCerts []pkix.RevokedCertificate, now, expiry *time.Time) (crlBytes []byte, err os.Error) {
+ tbsCertList := pkix.TBSCertificateList{
+ Version: 2,
+ Signature: pkix.AlgorithmIdentifier{
+ Algorithm: oidSignatureSHA1WithRSA,
+ },
+ Issuer: c.Subject.ToRDNSequence(),
+ ThisUpdate: now,
+ NextUpdate: expiry,
+ RevokedCertificates: revokedCerts,
+ }
+
+ tbsCertListContents, err := asn1.Marshal(tbsCertList)
+ if err != nil {
+ return
+ }
+
+ h := sha1.New()
+ h.Write(tbsCertListContents)
+ digest := h.Sum()
+
+ signature, err := rsa.SignPKCS1v15(rand, priv, crypto.SHA1, digest)
+ if err != nil {
+ return
+ }
+
+ return asn1.Marshal(pkix.CertificateList{
+ TBSCertList: tbsCertList,
+ SignatureAlgorithm: pkix.AlgorithmIdentifier{
+ Algorithm: oidSignatureSHA1WithRSA,
+ },
+ SignatureValue: asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
+ })
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-24 04:56:28 +0000