Add support to deprecated CRL functions for go1.18

Move and separate version-sensitive functionalities related to
CRL into two go files within the config package so that it can
build with the corresponding go version.

Signed-off-by: Ziqi Zhang <ziqi.zhang.ext@ericsson.com>

config/crl.go

@@ -0,0 +1,75 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file is built for It provides functionalities to parse raw CRLs,
+// check their validity and verify their signatures against provided
+// certificates (CAs). It also allows checking the revocation status of the
+// provided certificates.
+
+// It is built for Go versions after and include Go version 1.19 as there
+// are new functionality related to CRL handling.
+
+//go:build go1.19
+// +build go1.19
+
+package config
+
+import (
+	"crypto/x509"
+	"encoding/pem"
+	"fmt"
+	"time"
+)
+
+// Parse all CRLs and return a slice of valid CRLs.
+func parseCRLs(rawCRL []byte, cAs []*x509.Certificate) ([]*x509.RevocationList, error) {
+	var crls []*x509.RevocationList
+	for p, r := pem.Decode(rawCRL); p != nil; p, r = pem.Decode(r) {
+		if p.Type != "X509 CRL" {
+			return nil, fmt.Errorf("unable to decode raw certificate revocation list")
+		}
+		crl, err := x509.ParseRevocationList(p.Bytes)
+		if err != nil {
+			return nil, err
+		}
+
+		// Check CRL exipry status.
+		if crl.NextUpdate.Before(time.Now()) {
+			return nil, fmt.Errorf("certificate revocation list is outdated")
+		}
+
+		// Check each CRL is signed by any CA, if not, ignore the CRL.
+		// Otherwise, append to the valid slice of CRL.
+		for _, ca := range cAs {
+			err = crl.CheckSignatureFrom(ca)
+			if err == nil {
+				crls = append(crls, crl)
+				break
+			}
+		}
+	}
+	return crls, nil
+}
+
+func validRevocationStatus(cAs []*x509.Certificate, cRLs []*x509.RevocationList) error {
+	for _, cert := range cAs {
+		for _, crl := range cRLs {
+			for _, revokedCertificate := range crl.RevokedCertificates {
+				if revokedCertificate.SerialNumber.Cmp(cert.SerialNumber) == 0 {
+					return fmt.Errorf("certificate was revoked")
+				}
+			}
+		}
+	}
+	return nil
+}

config/crl_deprecated.go

@@ -0,0 +1,76 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file is built for It provides functionalities to parse raw CRLs,
+// check their validity and verify their signatures against provided
+// certificates (CAs). It also allows checking the revocation status of the
+// provided certificates.
+
+// It is built for Go versions before 1.19 as there are deprecated
+// functionality related to CRL handling.
+
+//go:build !go1.19
+// +build !go1.19
+
+package config
+
+import (
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"fmt"
+	"time"
+)
+
+// Parse all CRLs and return a slice of valid CRLs.
+func parseCRLs(rawCRL []byte, cAs []*x509.Certificate) ([]*pkix.CertificateList, error) {
+	var crls []*pkix.CertificateList
+	for p, r := pem.Decode(rawCRL); p != nil; p, r = pem.Decode(r) {
+		if p.Type != "X509 CRL" {
+			return nil, fmt.Errorf("unable to decode raw certificate revocation list")
+		}
+		crl, err := x509.ParseCRL(p.Bytes)
+		if err != nil {
+			return nil, err
+		}
+
+		// Check CRL exipry status.
+		if crl.TBSCertList.NextUpdate.Before(time.Now()) {
+			return nil, fmt.Errorf("certificate revocation list is outdated")
+		}
+
+		// Check each CRL is signed by any CA, if not, ignore the CRL.
+		// Otherwise, append to the valid slice of CRL.
+		for _, ca := range cAs {
+			err = ca.CheckCRLSignature(crl)
+			if err == nil {
+				crls = append(crls, crl)
+				break
+			}
+		}
+	}
+	return crls, nil
+}
+
+func validRevocationStatus(cAs []*x509.Certificate, cRLs []*pkix.CertificateList) error {
+	for _, cert := range cAs {
+		for _, crl := range cRLs {
+			for _, revokedCertificate := range crl.TBSCertList.RevokedCertificates {
+				if revokedCertificate.SerialNumber.Cmp(cert.SerialNumber) == 0 {
+					return fmt.Errorf("certificate was revoked")
+				}
+			}
+		}
+	}
+	return nil
+}

config/http_config.go

@@ -1356,49 +1356,14 @@ func (c *TLSConfig) verifyPeerCertificate(rawCerts [][]byte, verifiedChains [][]
 	// against valid CRLs.
 	cAs = append(cAs, verifiedChains[0][0])
 
-	for _, cert := range cAs {
-		for _, crl := range crlsList {
-			for _, revokedCertificate := range crl.RevokedCertificates {
-				if revokedCertificate.SerialNumber.Cmp(cert.SerialNumber) == 0 {
-					return fmt.Errorf("certificate was revoked")
-				}
-			}
-		}
+	err = validRevocationStatus(cAs, crlsList)
+	if err != nil {
+		return err
 	}
 
 	return nil
 }
 
-// Parse all CRLs and return a slice of valid CRLs.
-func parseCRLs(rawCRL []byte, cAs []*x509.Certificate) ([]*x509.RevocationList, error) {
-	var crls []*x509.RevocationList
-	for p, r := pem.Decode(rawCRL); p != nil; p, r = pem.Decode(r) {
-		if p.Type != "X509 CRL" {
-			return nil, fmt.Errorf("unable to decode raw certificate revocation list")
-		}
-		crl, err := x509.ParseRevocationList(p.Bytes)
-		if err != nil {
-			return nil, err
-		}
-
-		// Check CRL exipry status.
-		if crl.NextUpdate.Before(time.Now()) {
-			return nil, fmt.Errorf("certificate revocation list is outdated")
-		}
-
-		// Check each CRL is signed by any CA, if not, ignore the CRL.
-		// Otherwise, append to the valid slice of CRL.
-		for _, ca := range cAs {
-			err = crl.CheckSignatureFrom(ca)
-			if err == nil {
-				crls = append(crls, crl)
-				break
-			}
-		}
-	}
-	return crls, nil
-}
-
 // Parse raw certificates with padding structure.
 func parseCerts(rawCerts []byte) ([]*x509.Certificate, error) {
 	var certList []*x509.Certificate

config/http_config_test.go

@@ -2139,7 +2139,7 @@ func TestNewClientFromRevokedCertConfig(t *testing.T) {
 			handler: func(w http.ResponseWriter, r *http.Request) {
 				fmt.Fprint(w, ExpectedMessage)
 			},
-		}, { // Full chain of CA and the single root CA revoke the intermediate CA certificate.
+		}, { // Full chain of CA and CRL, the single root CA revoke the intermediate CA certificate.
 			clientConfig: HTTPClientConfig{
 				TLSConfig: TLSConfig{
 					CAFile:             TLSCAChainPath,
@@ -2152,7 +2152,8 @@ func TestNewClientFromRevokedCertConfig(t *testing.T) {
 			handler: func(w http.ResponseWriter, r *http.Request) {
 				fmt.Fprint(w, ExpectedMessage)
 			},
-		}, { // Missing root in the CA Chain and the full chain of CRLs, the Intermediate CA revoke the peer certificate.
+		}, { // Missing root in the CA Chain and the full chain of CRLs,
+			//  the Intermediate CA revoke the peer certificate.
 			clientConfig: HTTPClientConfig{
 				TLSConfig: TLSConfig{
 					CAFile:             TLSCACHainNoRootPath,