smx509: add new CRL parser, deprecate old one #40

smx509/parser.go

@@ -7,6 +7,7 @@ import (
 	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/rsa"
+	"crypto/x509"
 	"crypto/x509/pkix"
 	"encoding/asn1"
 	"encoding/pem"
@@ -162,6 +163,23 @@ func parseAI(der cryptobyte.String) (pkix.AlgorithmIdentifier, error) {
 	return ai, nil
 }
 
+func parseTime(der *cryptobyte.String) (time.Time, error) {
+	var t time.Time
+	switch {
+	case der.PeekASN1Tag(cryptobyte_asn1.UTCTime):
+		if !der.ReadASN1UTCTime(&t) {
+			return t, errors.New("x509: malformed UTCTime")
+		}
+	case der.PeekASN1Tag(cryptobyte_asn1.GeneralizedTime):
+		if !der.ReadASN1GeneralizedTime(&t) {
+			return t, errors.New("x509: malformed GeneralizedTime")
+		}
+	default:
+		return t, errors.New("x509: unsupported time format")
+	}
+	return t, nil
+}
+
 func parseValidity(der cryptobyte.String) (time.Time, time.Time, error) {
 	extract := func() (time.Time, error) {
 		var t time.Time
@@ -457,6 +475,26 @@ func parseSANExtension(der cryptobyte.String) (dnsNames, emailAddresses []string
 	return
 }
 
+func parseAuthorityKeyIdentifier(e pkix.Extension) ([]byte, error) {
+	// RFC 5280, Section 4.2.1.1
+	if e.Critical {
+		// Conforming CAs MUST mark this extension as non-critical
+		return nil, errors.New("x509: authority key identifier incorrectly marked critical")
+	}
+	val := cryptobyte.String(e.Value)
+	var akid cryptobyte.String
+	if !val.ReadASN1(&akid, cryptobyte_asn1.SEQUENCE) {
+		return nil, errors.New("x509: invalid authority key identifier")
+	}
+	if akid.PeekASN1Tag(cryptobyte_asn1.Tag(0).ContextSpecific()) {
+		if !akid.ReadASN1(&akid, cryptobyte_asn1.Tag(0).ContextSpecific()) {
+			return nil, errors.New("x509: invalid authority key identifier")
+		}
+		return akid, nil
+	}
+	return nil, nil
+}
+
 func parseExtKeyUsageExtension(der cryptobyte.String) ([]ExtKeyUsage, []asn1.ObjectIdentifier, error) {
 	var extKeyUsages []ExtKeyUsage
 	var unknownUsages []asn1.ObjectIdentifier
@@ -1068,3 +1106,191 @@ func ParseCertificatePEM(data []byte) (*Certificate, error) {
 	}
 	return ParseCertificate(block.Bytes)
 }
+
+// The X.509 standards confusingly 1-indexed the version names, but 0-indexed
+// the actual encoded version, so the version for X.509v2 is 1.
+const x509v2Version = 1
+
+// ParseRevocationList parses a X509 v2 [Certificate] Revocation List from the given
+// ASN.1 DER data.
+func ParseRevocationList(der []byte) (*RevocationList, error) {
+	rl := &RevocationList{}
+
+	input := cryptobyte.String(der)
+	// we read the SEQUENCE including length and tag bytes so that
+	// we can populate RevocationList.Raw, before unwrapping the
+	// SEQUENCE so it can be operated on
+	if !input.ReadASN1Element(&input, cryptobyte_asn1.SEQUENCE) {
+		return nil, errors.New("x509: malformed crl")
+	}
+	rl.Raw = input
+	if !input.ReadASN1(&input, cryptobyte_asn1.SEQUENCE) {
+		return nil, errors.New("x509: malformed crl")
+	}
+
+	var tbs cryptobyte.String
+	// do the same trick again as above to extract the raw
+	// bytes for Certificate.RawTBSCertificate
+	if !input.ReadASN1Element(&tbs, cryptobyte_asn1.SEQUENCE) {
+		return nil, errors.New("x509: malformed tbs crl")
+	}
+	rl.RawTBSRevocationList = tbs
+	if !tbs.ReadASN1(&tbs, cryptobyte_asn1.SEQUENCE) {
+		return nil, errors.New("x509: malformed tbs crl")
+	}
+
+	var version int
+	if !tbs.PeekASN1Tag(cryptobyte_asn1.INTEGER) {
+		return nil, errors.New("x509: unsupported crl version")
+	}
+	if !tbs.ReadASN1Integer(&version) {
+		return nil, errors.New("x509: malformed crl")
+	}
+	if version != x509v2Version {
+		return nil, fmt.Errorf("x509: unsupported crl version: %d", version)
+	}
+
+	var sigAISeq cryptobyte.String
+	if !tbs.ReadASN1(&sigAISeq, cryptobyte_asn1.SEQUENCE) {
+		return nil, errors.New("x509: malformed signature algorithm identifier")
+	}
+	// Before parsing the inner algorithm identifier, extract
+	// the outer algorithm identifier and make sure that they
+	// match.
+	var outerSigAISeq cryptobyte.String
+	if !input.ReadASN1(&outerSigAISeq, cryptobyte_asn1.SEQUENCE) {
+		return nil, errors.New("x509: malformed algorithm identifier")
+	}
+	if !bytes.Equal(outerSigAISeq, sigAISeq) {
+		return nil, errors.New("x509: inner and outer signature algorithm identifiers don't match")
+	}
+	sigAI, err := parseAI(sigAISeq)
+	if err != nil {
+		return nil, err
+	}
+	rl.SignatureAlgorithm = getSignatureAlgorithmFromAI(sigAI)
+
+	var signature asn1.BitString
+	if !input.ReadASN1BitString(&signature) {
+		return nil, errors.New("x509: malformed signature")
+	}
+	rl.Signature = signature.RightAlign()
+
+	var issuerSeq cryptobyte.String
+	if !tbs.ReadASN1Element(&issuerSeq, cryptobyte_asn1.SEQUENCE) {
+		return nil, errors.New("x509: malformed issuer")
+	}
+	rl.RawIssuer = issuerSeq
+	issuerRDNs, err := ParseName(issuerSeq)
+	if err != nil {
+		return nil, err
+	}
+	rl.Issuer.FillFromRDNSequence(issuerRDNs)
+
+	rl.ThisUpdate, err = parseTime(&tbs)
+	if err != nil {
+		return nil, err
+	}
+	if tbs.PeekASN1Tag(cryptobyte_asn1.GeneralizedTime) || tbs.PeekASN1Tag(cryptobyte_asn1.UTCTime) {
+		rl.NextUpdate, err = parseTime(&tbs)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if tbs.PeekASN1Tag(cryptobyte_asn1.SEQUENCE) {
+		var revokedSeq cryptobyte.String
+		if !tbs.ReadASN1(&revokedSeq, cryptobyte_asn1.SEQUENCE) {
+			return nil, errors.New("x509: malformed crl")
+		}
+		for !revokedSeq.Empty() {
+			rce := x509.RevocationListEntry{}
+
+			var certSeq cryptobyte.String
+			if !revokedSeq.ReadASN1Element(&certSeq, cryptobyte_asn1.SEQUENCE) {
+				return nil, errors.New("x509: malformed crl")
+			}
+			rce.Raw = certSeq
+			if !certSeq.ReadASN1(&certSeq, cryptobyte_asn1.SEQUENCE) {
+				return nil, errors.New("x509: malformed crl")
+			}
+
+			rce.SerialNumber = new(big.Int)
+			if !certSeq.ReadASN1Integer(rce.SerialNumber) {
+				return nil, errors.New("x509: malformed serial number")
+			}
+			rce.RevocationTime, err = parseTime(&certSeq)
+			if err != nil {
+				return nil, err
+			}
+			var extensions cryptobyte.String
+			var present bool
+			if !certSeq.ReadOptionalASN1(&extensions, &present, cryptobyte_asn1.SEQUENCE) {
+				return nil, errors.New("x509: malformed extensions")
+			}
+			if present {
+				for !extensions.Empty() {
+					var extension cryptobyte.String
+					if !extensions.ReadASN1(&extension, cryptobyte_asn1.SEQUENCE) {
+						return nil, errors.New("x509: malformed extension")
+					}
+					ext, err := parseExtension(extension)
+					if err != nil {
+						return nil, err
+					}
+					if ext.Id.Equal(oidExtensionReasonCode) {
+						val := cryptobyte.String(ext.Value)
+						if !val.ReadASN1Enum(&rce.ReasonCode) {
+							return nil, fmt.Errorf("x509: malformed reasonCode extension")
+						}
+					}
+					rce.Extensions = append(rce.Extensions, ext)
+				}
+			}
+
+			rl.RevokedCertificateEntries = append(rl.RevokedCertificateEntries, rce)
+			rcDeprecated := pkix.RevokedCertificate{
+				SerialNumber:   rce.SerialNumber,
+				RevocationTime: rce.RevocationTime,
+				Extensions:     rce.Extensions,
+			}
+			rl.RevokedCertificates = append(rl.RevokedCertificates, rcDeprecated)
+		}
+	}
+
+	var extensions cryptobyte.String
+	var present bool
+	if !tbs.ReadOptionalASN1(&extensions, &present, cryptobyte_asn1.Tag(0).Constructed().ContextSpecific()) {
+		return nil, errors.New("x509: malformed extensions")
+	}
+	if present {
+		if !extensions.ReadASN1(&extensions, cryptobyte_asn1.SEQUENCE) {
+			return nil, errors.New("x509: malformed extensions")
+		}
+		for !extensions.Empty() {
+			var extension cryptobyte.String
+			if !extensions.ReadASN1(&extension, cryptobyte_asn1.SEQUENCE) {
+				return nil, errors.New("x509: malformed extension")
+			}
+			ext, err := parseExtension(extension)
+			if err != nil {
+				return nil, err
+			}
+			if ext.Id.Equal(oidExtensionAuthorityKeyId) {
+				rl.AuthorityKeyId, err = parseAuthorityKeyIdentifier(ext)
+				if err != nil {
+					return nil, err
+				}
+			} else if ext.Id.Equal(oidExtensionCRLNumber) {
+				value := cryptobyte.String(ext.Value)
+				rl.Number = new(big.Int)
+				if !value.ReadASN1Integer(rl.Number) {
+					return nil, errors.New("x509: malformed crl number")
+				}
+			}
+			rl.Extensions = append(rl.Extensions, ext)
+		}
+	}
+
+	return rl, nil
+}

smx509/x509.go

@@ -885,6 +885,7 @@ func checkSignature(algo SignatureAlgorithm, signed, signature []byte, publicKey
 }
 
 // CheckCRLSignature checks that the signature in crl is from c.
+// Deprecated: Use RevocationList.CheckSignatureFrom instead.
 func (c *Certificate) CheckCRLSignature(crl *pkix.CertificateList) error {
 	algo := getSignatureAlgorithmFromAI(crl.SignatureAlgorithm)
 	return c.CheckSignature(algo, crl.TBSCertList.Raw, crl.SignatureValue.RightAlign())
@@ -1641,11 +1642,15 @@ func toCertificate(in any) (*x509.Certificate, error) {
 // 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.
+//
+// Deprecated: Use [ParseRevocationList] instead.
 func ParseCRL(crlBytes []byte) (*pkix.CertificateList, error) {
 	return x509.ParseCRL(crlBytes)
 }
 
 // ParseDERCRL parses a DER encoded CRL from the given bytes.
+//
+// Deprecated: Use [ParseRevocationList] instead.
 func ParseDERCRL(derBytes []byte) (*pkix.CertificateList, error) {
 	return x509.ParseDERCRL(derBytes)
 }
@@ -1653,8 +1658,8 @@ func ParseDERCRL(derBytes []byte) (*pkix.CertificateList, error) {
 // CreateCRL returns a DER encoded CRL, signed by this Certificate, that
 // contains the given list of revoked certificates.
 //
-// Note: this method does not generate an RFC 5280 conformant X.509 v2 CRL.
-// To generate a standards compliant CRL, use CreateRevocationList instead.
+// Deprecated: this method does not generate an RFC 5280 conformant X.509 v2 CRL.
+// To generate a standards compliant CRL, use [CreateRevocationList] instead.
 func (c *Certificate) CreateCRL(rand io.Reader, priv any, revokedCerts []pkix.RevokedCertificate, now, expiry time.Time) (crlBytes []byte, err error) {
 	key, ok := priv.(crypto.Signer)
 	if !ok {
@@ -2064,6 +2069,16 @@ func (c *CertificateRequest) CheckSignature() error {
 	return checkSignature(c.SignatureAlgorithm, c.RawTBSCertificateRequest, c.Signature, c.PublicKey, true)
 }
 
+type RevocationList x509.RevocationList
+
+func (c *RevocationList) asX509() *x509.RevocationList {
+	return (*x509.RevocationList)(c)
+}
+
+func (c *RevocationList) ToX509() *x509.RevocationList {
+	return c.asX509()
+}
+
 // These structures reflect the ASN.1 structure of X.509 CRLs better than
 // the existing crypto/x509/pkix variants do. These mirror the existing
 // certificate structs in this file.
@@ -2125,12 +2140,6 @@ func CreateRevocationList(rand io.Reader, template *x509.RevocationList, issuer
 	}
 
 	var revokedCerts []pkix.RevokedCertificate
-	revokedCerts = make([]pkix.RevokedCertificate, len(template.RevokedCertificates))
-	for i, rc := range template.RevokedCertificates {
-		rc.RevocationTime = rc.RevocationTime.UTC()
-		revokedCerts[i] = rc
-	}
-	/*
 	// Only process the deprecated RevokedCertificates field if it is populated
 	// and the new RevokedCertificateEntries field is not populated.
 	if len(template.RevokedCertificates) > 0 && len(template.RevokedCertificateEntries) == 0 {
@@ -2187,7 +2196,6 @@ func CreateRevocationList(rand io.Reader, template *x509.RevocationList, issuer
 			revokedCerts[i] = rc
 		}
 	}
-	*/
 
 	aki, err := asn1.Marshal(authKeyId{Id: issuer.SubjectKeyId})
 	if err != nil {
@@ -2252,3 +2260,22 @@ func CreateRevocationList(rand io.Reader, template *x509.RevocationList, issuer
 		SignatureValue:     asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
 	})
 }
+
+// CheckSignatureFrom verifies that the signature on rl is a valid signature
+// from issuer.
+func (rl *RevocationList) CheckSignatureFrom(parent *Certificate) error {
+	if parent.Version == 3 && !parent.BasicConstraintsValid ||
+		parent.BasicConstraintsValid && !parent.IsCA {
+		return x509.ConstraintViolationError{}
+	}
+
+	if parent.KeyUsage != 0 && parent.KeyUsage&KeyUsageCRLSign == 0 {
+		return x509.ConstraintViolationError{}
+	}
+
+	if parent.PublicKeyAlgorithm == UnknownPublicKeyAlgorithm {
+		return x509.ErrUnsupportedAlgorithm
+	}
+
+	return parent.CheckSignature(rl.SignatureAlgorithm, rl.RawTBSRevocationList, rl.Signature)
+}

smx509/x509_test.go

@@ -2414,6 +2414,57 @@ func TestCreateRevocationList(t *testing.T) {
 				NextUpdate: time.Time{}.Add(time.Hour * 48),
 			},
 		},
+		{
+			name: "valid, reason code",
+			key:  sm2Priv,
+			issuer: &x509.Certificate{
+				KeyUsage: KeyUsageCRLSign,
+				Subject: pkix.Name{
+					CommonName: "testing",
+				},
+				SubjectKeyId: []byte{1, 2, 3},
+			},
+			template: &x509.RevocationList{
+				RevokedCertificateEntries: []x509.RevocationListEntry{
+					{
+						SerialNumber:   big.NewInt(2),
+						RevocationTime: time.Time{}.Add(time.Hour),
+						ReasonCode:     1,
+					},
+				},
+				Number:     big.NewInt(5),
+				ThisUpdate: time.Time{}.Add(time.Hour * 24),
+				NextUpdate: time.Time{}.Add(time.Hour * 48),
+			},
+		},
+		{
+			name: "valid, extra entry extension",
+			key:  sm2Priv,
+			issuer: &x509.Certificate{
+				KeyUsage: KeyUsageCRLSign,
+				Subject: pkix.Name{
+					CommonName: "testing",
+				},
+				SubjectKeyId: []byte{1, 2, 3},
+			},
+			template: &x509.RevocationList{
+				RevokedCertificateEntries: []x509.RevocationListEntry{
+					{
+						SerialNumber:   big.NewInt(2),
+						RevocationTime: time.Time{}.Add(time.Hour),
+						ExtraExtensions: []pkix.Extension{
+							{
+								Id:    []int{2, 5, 29, 99},
+								Value: []byte{5, 0},
+							},
+						},
+					},
+				},
+				Number:     big.NewInt(5),
+				ThisUpdate: time.Time{}.Add(time.Hour * 24),
+				NextUpdate: time.Time{}.Add(time.Hour * 48),
+			},
+		},		
 		{
 			name: "valid, Ed25519 key",
 			key:  ed25519Priv,
@@ -2487,6 +2538,34 @@ func TestCreateRevocationList(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "valid, deprecated entries with extension",
+			key:  sm2Priv,
+			issuer: &x509.Certificate{
+				KeyUsage: KeyUsageCRLSign,
+				Subject: pkix.Name{
+					CommonName: "testing",
+				},
+				SubjectKeyId: []byte{1, 2, 3},
+			},
+			template: &x509.RevocationList{
+				RevokedCertificates: []pkix.RevokedCertificate{
+					{
+						SerialNumber:   big.NewInt(2),
+						RevocationTime: time.Time{}.Add(time.Hour),
+						Extensions: []pkix.Extension{
+							{
+								Id:    []int{2, 5, 29, 99},
+								Value: []byte{5, 0},
+							},
+						},
+					},
+				},
+				Number:     big.NewInt(5),
+				ThisUpdate: time.Time{}.Add(time.Hour * 24),
+				NextUpdate: time.Time{}.Add(time.Hour * 48),
+			},
+		},
 		{
 			name: "valid, empty list",
 			key:  sm2Priv,
@@ -2533,24 +2612,45 @@ func TestCreateRevocationList(t *testing.T) {
 				return
 			}
 
-			parsedCRL, err := ParseDERCRL(crl)
+			parsedCRL, err := ParseRevocationList(crl)
 			if err != nil {
 				t.Fatalf("Failed to parse generated CRL: %s", err)
 			}
 
 			if tc.template.SignatureAlgorithm != UnknownSignatureAlgorithm &&
-				parsedCRL.SignatureAlgorithm.Algorithm.Equal(signatureAlgorithmDetails[tc.template.SignatureAlgorithm].oid) {
+				parsedCRL.SignatureAlgorithm != tc.template.SignatureAlgorithm {
 				t.Fatalf("SignatureAlgorithm mismatch: got %v; want %v.", parsedCRL.SignatureAlgorithm,
 					tc.template.SignatureAlgorithm)
 			}
-
-			if !reflect.DeepEqual(parsedCRL.TBSCertList.RevokedCertificates, tc.template.RevokedCertificates) {
+			if len(tc.template.RevokedCertificates) > 0 {
+				if !reflect.DeepEqual(parsedCRL.RevokedCertificates, tc.template.RevokedCertificates) {
 					t.Fatalf("RevokedCertificates mismatch: got %v; want %v.",
-					parsedCRL.TBSCertList.RevokedCertificates, tc.template.RevokedCertificates)
+						parsedCRL.RevokedCertificates, tc.template.RevokedCertificates)
 				}
-
-			if len(parsedCRL.TBSCertList.Extensions) != 2+len(tc.template.ExtraExtensions) {
-				t.Fatalf("Generated CRL has wrong number of extensions, wanted: %d, got: %d", 2+len(tc.template.ExtraExtensions), len(parsedCRL.TBSCertList.Extensions))
+			} else {
+				if len(parsedCRL.RevokedCertificateEntries) != len(tc.template.RevokedCertificateEntries) {
+					t.Fatalf("RevokedCertificateEntries length mismatch: got %d; want %d.",
+						len(parsedCRL.RevokedCertificateEntries),
+						len(tc.template.RevokedCertificateEntries))
+				}
+				for i, rce := range parsedCRL.RevokedCertificateEntries {
+					expected := tc.template.RevokedCertificateEntries[i]
+					if rce.SerialNumber.Cmp(expected.SerialNumber) != 0 {
+						t.Fatalf("RevocationListEntry serial mismatch: got %d; want %d.",
+							rce.SerialNumber, expected.SerialNumber)
+					}
+					if !rce.RevocationTime.Equal(expected.RevocationTime) {
+						t.Fatalf("RevocationListEntry revocation time mismatch: got %v; want %v.",
+							rce.RevocationTime, expected.RevocationTime)
+					}
+					if rce.ReasonCode != expected.ReasonCode {
+						t.Fatalf("RevocationListEntry reason code mismatch: got %d; want %d.",
+							rce.ReasonCode, expected.ReasonCode)
+					}
+				}
+			}
+			if len(parsedCRL.Extensions) != 2+len(tc.template.ExtraExtensions) {
+				t.Fatalf("Generated CRL has wrong number of extensions, wanted: %d, got: %d", 2+len(tc.template.ExtraExtensions), len(parsedCRL.Extensions))
 			}
 			expectedAKI, err := asn1.Marshal(authKeyId{Id: tc.issuer.SubjectKeyId})
 			if err != nil {
@@ -2560,9 +2660,9 @@ func TestCreateRevocationList(t *testing.T) {
 				Id:    oidExtensionAuthorityKeyId,
 				Value: expectedAKI,
 			}
-			if !reflect.DeepEqual(parsedCRL.TBSCertList.Extensions[0], akiExt) {
+			if !reflect.DeepEqual(parsedCRL.Extensions[0], akiExt) {
 				t.Fatalf("Unexpected first extension: got %v, want %v",
-					parsedCRL.TBSCertList.Extensions[0], akiExt)
+					parsedCRL.Extensions[0], akiExt)
 			}
 			expectedNum, err := asn1.Marshal(tc.template.Number)
 			if err != nil {
@@ -2572,18 +2672,57 @@ func TestCreateRevocationList(t *testing.T) {
 				Id:    oidExtensionCRLNumber,
 				Value: expectedNum,
 			}
-			if !reflect.DeepEqual(parsedCRL.TBSCertList.Extensions[1], crlExt) {
+			if !reflect.DeepEqual(parsedCRL.Extensions[1], crlExt) {
 				t.Fatalf("Unexpected second extension: got %v, want %v",
-					parsedCRL.TBSCertList.Extensions[1], crlExt)
+					parsedCRL.Extensions[1], crlExt)
 			}
-			if len(parsedCRL.TBSCertList.Extensions[2:]) == 0 && len(tc.template.ExtraExtensions) == 0 {
+						// With Go 1.19's updated RevocationList, we can now directly compare
+			// the RawSubject of the certificate to RawIssuer on the parsed CRL.
+			// However, this doesn't work with our hacked issuers above (that
+			// aren't parsed from a proper DER bundle but are instead manually
+			// constructed). Prefer RawSubject when it is set.
+			if len(tc.issuer.RawSubject) > 0 {
+				issuerSubj, err := subjectBytes(tc.issuer)
+				if err != nil {
+					t.Fatalf("failed to get issuer subject: %s", err)
+				}
+				if !bytes.Equal(issuerSubj, parsedCRL.RawIssuer) {
+					t.Fatalf("Unexpected issuer subject; wanted: %v, got: %v", hex.EncodeToString(issuerSubj), hex.EncodeToString(parsedCRL.RawIssuer))
+				}
+			} else {
+				// When we hack our custom Subject in the test cases above,
+				// we don't set the additional fields (such as Names) in the
+				// hacked issuer. Round-trip a parsing of pkix.Name so that
+				// we add these missing fields for the comparison.
+				issuerRDN := tc.issuer.Subject.ToRDNSequence()
+				var caIssuer pkix.Name
+				caIssuer.FillFromRDNSequence(&issuerRDN)
+				if !reflect.DeepEqual(caIssuer, parsedCRL.Issuer) {
+					t.Fatalf("Expected issuer.Subject, parsedCRL.Issuer to be the same; wanted: %#v, got: %#v", caIssuer, parsedCRL.Issuer)
+				}
+			}
+
+			if len(parsedCRL.Extensions[2:]) == 0 && len(tc.template.ExtraExtensions) == 0 {
 				// If we don't have anything to check return early so we don't
 				// hit a [] != nil false positive below.
 				return
 			}
-			if !reflect.DeepEqual(parsedCRL.TBSCertList.Extensions[2:], tc.template.ExtraExtensions) {
+			if !reflect.DeepEqual(parsedCRL.Extensions[2:], tc.template.ExtraExtensions) {
 				t.Fatalf("Extensions mismatch: got %v; want %v.",
-					parsedCRL.TBSCertList.Extensions[2:], tc.template.ExtraExtensions)
+					parsedCRL.Extensions[2:], tc.template.ExtraExtensions)
+			}
+
+			if tc.template.Number != nil && parsedCRL.Number == nil {
+				t.Fatalf("Generated CRL missing Number: got nil, want %s",
+					tc.template.Number.String())
+			}
+			if tc.template.Number != nil && tc.template.Number.Cmp(parsedCRL.Number) != 0 {
+				t.Fatalf("Generated CRL has wrong Number: got %s, want %s",
+					parsedCRL.Number.String(), tc.template.Number.String())
+			}
+			if !bytes.Equal(parsedCRL.AuthorityKeyId, tc.issuer.SubjectKeyId) {
+				t.Fatalf("Generated CRL has wrong AuthorityKeyId: got %x, want %x",
+					parsedCRL.AuthorityKeyId, tc.issuer.SubjectKeyId)
 			}
 		})
 	}
@@ -3150,12 +3289,12 @@ func TestDisableSHA1ForCertOnly(t *testing.T) {
 		t.Fatalf("failed to generate test CRL: %s", err)
 	}
 	// TODO(rolandshoemaker): this should be ParseRevocationList once it lands
-	crl, err := ParseCRL(crlDER)
+	crl, err := ParseRevocationList(crlDER)
 	if err != nil {
 		t.Fatalf("failed to parse test CRL: %s", err)
 	}
 
-	if err = cert.CheckCRLSignature(crl); err != nil {
+	if err = crl.CheckSignatureFrom(cert); err != nil {
 		t.Errorf("unexpected error: %s", err)
 	}
 
@@ -3174,6 +3313,129 @@ func TestDisableSHA1ForCertOnly(t *testing.T) {
 	}
 }
 
+func TestParseRevocationList(t *testing.T) {
+	derBytes := fromBase64(derCRLBase64)
+	certList, err := ParseRevocationList(derBytes)
+	if err != nil {
+		t.Errorf("error parsing: %s", err)
+		return
+	}
+	numCerts := len(certList.RevokedCertificateEntries)
+	numCertsDeprecated := len(certList.RevokedCertificateEntries)
+	expected := 88
+	if numCerts != expected || numCertsDeprecated != expected {
+		t.Errorf("bad number of revoked certificates. got: %d want: %d", numCerts, expected)
+	}
+}
+
+func TestRevocationListCheckSignatureFrom(t *testing.T) {
+	goodKey, err := sm2.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatalf("failed to generate test key: %s", err)
+	}
+	badKey, err := sm2.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatalf("failed to generate test key: %s", err)
+	}
+	tests := []struct {
+		name   string
+		issuer *Certificate
+		err    string
+	}{
+		{
+			name: "valid",
+			issuer: &Certificate{
+				Version:               3,
+				BasicConstraintsValid: true,
+				IsCA:                  true,
+				PublicKeyAlgorithm:    ECDSA,
+				PublicKey:             goodKey.Public(),
+			},
+		},
+		{
+			name: "valid, key usage set",
+			issuer: &Certificate{
+				Version:               3,
+				BasicConstraintsValid: true,
+				IsCA:                  true,
+				PublicKeyAlgorithm:    ECDSA,
+				PublicKey:             goodKey.Public(),
+				KeyUsage:              KeyUsageCRLSign,
+			},
+		},
+		{
+			name: "invalid issuer, wrong key usage",
+			issuer: &Certificate{
+				Version:               3,
+				BasicConstraintsValid: true,
+				IsCA:                  true,
+				PublicKeyAlgorithm:    ECDSA,
+				PublicKey:             goodKey.Public(),
+				KeyUsage:              KeyUsageCertSign,
+			},
+			err: "x509: invalid signature: parent certificate cannot sign this kind of certificate",
+		},
+		{
+			name: "invalid issuer, no basic constraints/ca",
+			issuer: &Certificate{
+				Version:            3,
+				PublicKeyAlgorithm: ECDSA,
+				PublicKey:          goodKey.Public(),
+			},
+			err: "x509: invalid signature: parent certificate cannot sign this kind of certificate",
+		},
+		{
+			name: "invalid issuer, unsupported public key type",
+			issuer: &Certificate{
+				Version:               3,
+				BasicConstraintsValid: true,
+				IsCA:                  true,
+				PublicKeyAlgorithm:    UnknownPublicKeyAlgorithm,
+				PublicKey:             goodKey.Public(),
+			},
+			err: "x509: cannot verify signature: algorithm unimplemented",
+		},
+		{
+			name: "wrong key",
+			issuer: &Certificate{
+				Version:               3,
+				BasicConstraintsValid: true,
+				IsCA:                  true,
+				PublicKeyAlgorithm:    ECDSA,
+				PublicKey:             badKey.Public(),
+			},
+			err: "x509: SM2 verification failure",
+		},
+	}
+
+	crlIssuer := &Certificate{
+		BasicConstraintsValid: true,
+		IsCA:                  true,
+		PublicKeyAlgorithm:    ECDSA,
+		PublicKey:             goodKey.Public(),
+		KeyUsage:              KeyUsageCRLSign,
+		SubjectKeyId:          []byte{1, 2, 3},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			crlDER, err := CreateRevocationList(rand.Reader, &x509.RevocationList{Number: big.NewInt(1)}, crlIssuer, goodKey)
+			if err != nil {
+				t.Fatalf("failed to generate CRL: %s", err)
+			}
+			crl, err := ParseRevocationList(crlDER)
+			if err != nil {
+				t.Fatalf("failed to parse test CRL: %s", err)
+			}
+			err = crl.CheckSignatureFrom(tc.issuer)
+			if err != nil && err.Error() != tc.err {
+				t.Errorf("unexpected error: got %s, want %s", err, tc.err)
+			} else if err == nil && tc.err != "" {
+				t.Errorf("CheckSignatureFrom did not fail: want %s", tc.err)
+			}
+		})
+	}
+}
+
 func TestOmitEmptyExtensions(t *testing.T) {
 	k, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
 	if err != nil {