crypto/x509: policy OID support and fixes.

* Add support for certificate policy identifiers
        * Fix the version number of generated certificates
        * Fix the parsing of version numbers
        * Fix the case of multiple name entries (it should have been a list of
          tagged values, not a tagged list of values).

R=r
CC=golang-dev
https://golang.org/cl/3044041

src/pkg/crypto/x509/x509.go

@@ -217,50 +217,40 @@ var (
 	oidPostalCode         = []int{2, 5, 4, 17}
 )
 
+// appendRDNs appends a relativeDistinguishedNameSET to the given rdnSequence
+// and returns the new value. The relativeDistinguishedNameSET contains an
+// attributeTypeAndValue for each of the given values. See RFC 5280, A.1, and
+// search for AttributeTypeAndValue.
+func appendRDNs(in rdnSequence, values []string, oid asn1.ObjectIdentifier) rdnSequence {
+	if len(values) == 0 {
+		return in
+	}
+
+	s := make([]attributeTypeAndValue, len(values))
+	for i, value := range values {
+		s[i].Type = oid
+		s[i].Value = value
+	}
+
+	return append(in, s)
+}
+
 func (n Name) toRDNSequence() (ret rdnSequence) {
-	ret = make([]relativeDistinguishedNameSET, 9 /* maximum number of elements */ )
-	i := 0
-	if len(n.Country) > 0 {
-		ret[i] = []attributeTypeAndValue{{oidCountry, n.Country}}
-		i++
-	}
-	if len(n.Organization) > 0 {
-		ret[i] = []attributeTypeAndValue{{oidOrganization, n.Organization}}
-		i++
-	}
-	if len(n.OrganizationalUnit) > 0 {
-		ret[i] = []attributeTypeAndValue{{oidOrganizationalUnit, n.OrganizationalUnit}}
-		i++
-	}
+	ret = appendRDNs(ret, n.Country, oidCountry)
+	ret = appendRDNs(ret, n.Organization, oidOrganization)
+	ret = appendRDNs(ret, n.OrganizationalUnit, oidOrganizationalUnit)
+	ret = appendRDNs(ret, n.Locality, oidLocatity)
+	ret = appendRDNs(ret, n.Province, oidProvince)
+	ret = appendRDNs(ret, n.StreetAddress, oidStreetAddress)
+	ret = appendRDNs(ret, n.PostalCode, oidPostalCode)
 	if len(n.CommonName) > 0 {
-		ret[i] = []attributeTypeAndValue{{oidCommonName, n.CommonName}}
-		i++
+		ret = appendRDNs(ret, []string{n.CommonName}, oidCommonName)
 	}
 	if len(n.SerialNumber) > 0 {
-		ret[i] = []attributeTypeAndValue{{oidSerialNumber, n.SerialNumber}}
-		i++
-	}
-	if len(n.Locality) > 0 {
-		ret[i] = []attributeTypeAndValue{{oidLocatity, n.Locality}}
-		i++
-	}
-	if len(n.Province) > 0 {
-		ret[i] = []attributeTypeAndValue{{oidProvince, n.Province}}
-		i++
-	}
-	if len(n.StreetAddress) > 0 {
-		ret[i] = []attributeTypeAndValue{{oidStreetAddress, n.StreetAddress}}
-		i++
-	}
-	if len(n.PostalCode) > 0 {
-		ret[i] = []attributeTypeAndValue{{oidPostalCode, n.PostalCode}}
-		i++
+		ret = appendRDNs(ret, []string{n.SerialNumber}, oidSerialNumber)
 	}
 
-	// Adding another RDN here? Remember to update the maximum number of
-	// elements in the make() at the top of the function.
-
-	return ret[0:i]
+	return ret
 }
 
 func getSignatureAlgorithmFromOID(oid []int) SignatureAlgorithm {
@@ -339,6 +329,8 @@ type Certificate struct {
 	// Subject Alternate Name values
 	DNSNames       []string
 	EmailAddresses []string
+
+	PolicyIdentifiers []asn1.ObjectIdentifier
 }
 
 // UnsupportedAlgorithmError results from attempting to perform an operation
@@ -476,6 +468,12 @@ type rsaPublicKey struct {
 	E int
 }
 
+// RFC 5280 4.2.1.4
+type policyInformation struct {
+	Policy asn1.ObjectIdentifier
+	// policyQualifiers omitted
+}
+
 func parsePublicKey(algo PublicKeyAlgorithm, asn1Data []byte) (interface{}, os.Error) {
 	switch algo {
 	case RSA:
@@ -517,7 +515,7 @@ func parseCertificate(in *certificate) (*Certificate, os.Error) {
 		return nil, err
 	}
 
-	out.Version = in.TBSCertificate.Version
+	out.Version = in.TBSCertificate.Version + 1
 	out.SerialNumber = in.TBSCertificate.SerialNumber.Bytes
 	out.Issuer.fillFromRDNSequence(&in.TBSCertificate.Issuer)
 	out.Subject.fillFromRDNSequence(&in.TBSCertificate.Subject)
@@ -623,6 +621,17 @@ func parseCertificate(in *certificate) (*Certificate, os.Error) {
 				}
 				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
+				}
 			}
 		}
 
@@ -688,10 +697,11 @@ var (
 	oidExtensionAuthorityKeyId      = []int{2, 5, 29, 35}
 	oidExtensionBasicConstraints    = []int{2, 5, 29, 19}
 	oidExtensionSubjectAltName      = []int{2, 5, 29, 17}
+	oidExtensionCertificatePolicies = []int{2, 5, 29, 32}
 )
 
 func buildExtensions(template *Certificate) (ret []extension, err os.Error) {
-	ret = make([]extension, 5 /* maximum number of elements. */ )
+	ret = make([]extension, 6 /* maximum number of elements. */ )
 	n := 0
 
 	if template.KeyUsage != 0 {
@@ -755,6 +765,19 @@ func buildExtensions(template *Certificate) (ret []extension, err os.Error) {
 		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++
+	}
+
 	// Adding another extension here? Remember to update the maximum number
 	// of elements in the make() at the top of the function.
 
@@ -796,7 +819,7 @@ func CreateCertificate(rand io.Reader, template, parent *Certificate, pub *rsa.P
 
 	encodedPublicKey := asn1.BitString{BitLength: len(asn1PublicKey) * 8, Bytes: asn1PublicKey}
 	c := tbsCertificate{
-		Version:            3,
+		Version:            2,
 		SerialNumber:       asn1.RawValue{Bytes: template.SerialNumber, Tag: 2},
 		SignatureAlgorithm: algorithmIdentifier{oidSHA1WithRSA},
 		Issuer:             parent.Subject.toRDNSequence(),

src/pkg/crypto/x509/x509_test.go

@@ -5,6 +5,7 @@
 package x509
 
 import (
+	"asn1"
 	"big"
 	"crypto/rand"
 	"crypto/rsa"
@@ -169,6 +170,8 @@ func TestCreateSelfSignedCertificate(t *testing.T) {
 		BasicConstraintsValid: true,
 		IsCA:                  true,
 		DNSNames:              []string{"test.example.com"},
+
+		PolicyIdentifiers: []asn1.ObjectIdentifier{[]int{1, 2, 3}},
 	}
 
 	derBytes, err := CreateCertificate(random, &template, &template, &priv.PublicKey, priv)
@@ -182,6 +185,11 @@ func TestCreateSelfSignedCertificate(t *testing.T) {
 		t.Errorf("Failed to parse certificate: %s", err)
 		return
 	}
+
+	if len(cert.PolicyIdentifiers) != 1 || !cert.PolicyIdentifiers[0].Equal(template.PolicyIdentifiers[0]) {
+		t.Errorf("Failed to parse policy identifiers: got:%#v want:%#v", cert.PolicyIdentifiers, template.PolicyIdentifiers)
+	}
+
 	err = cert.CheckSignatureFrom(cert)
 	if err != nil {
 		t.Errorf("Signature verification failed: %s", err)