forked from google/certificate-transparency-go
/
x509util.go
883 lines (830 loc) · 30.1 KB
/
x509util.go
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// Copyright 2016 Google Inc. All Rights Reserved.
//
// 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.
// Package x509util includes utility code for working with X.509
// certificates from the x509 package.
package x509util
import (
"bytes"
"crypto/dsa"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rsa"
"encoding/base64"
"encoding/hex"
"encoding/pem"
"errors"
"fmt"
"net"
"strconv"
ct "github.com/google/certificate-transparency-go"
"github.com/google/certificate-transparency-go/asn1"
"github.com/google/certificate-transparency-go/gossip/minimal/x509ext"
"github.com/google/certificate-transparency-go/tls"
"github.com/google/certificate-transparency-go/x509"
"github.com/google/certificate-transparency-go/x509/pkix"
)
// OIDForStandardExtension indicates whether oid identifies a standard extension.
// Standard extensions are listed in RFC 5280 (and other RFCs).
func OIDForStandardExtension(oid asn1.ObjectIdentifier) bool {
if oid.Equal(x509.OIDExtensionSubjectKeyId) ||
oid.Equal(x509.OIDExtensionKeyUsage) ||
oid.Equal(x509.OIDExtensionExtendedKeyUsage) ||
oid.Equal(x509.OIDExtensionAuthorityKeyId) ||
oid.Equal(x509.OIDExtensionBasicConstraints) ||
oid.Equal(x509.OIDExtensionSubjectAltName) ||
oid.Equal(x509.OIDExtensionCertificatePolicies) ||
oid.Equal(x509.OIDExtensionNameConstraints) ||
oid.Equal(x509.OIDExtensionCRLDistributionPoints) ||
oid.Equal(x509.OIDExtensionIssuerAltName) ||
oid.Equal(x509.OIDExtensionSubjectDirectoryAttributes) ||
oid.Equal(x509.OIDExtensionInhibitAnyPolicy) ||
oid.Equal(x509.OIDExtensionPolicyConstraints) ||
oid.Equal(x509.OIDExtensionPolicyMappings) ||
oid.Equal(x509.OIDExtensionFreshestCRL) ||
oid.Equal(x509.OIDExtensionSubjectInfoAccess) ||
oid.Equal(x509.OIDExtensionAuthorityInfoAccess) ||
oid.Equal(x509.OIDExtensionIPPrefixList) ||
oid.Equal(x509.OIDExtensionASList) ||
oid.Equal(x509.OIDExtensionCTPoison) ||
oid.Equal(x509.OIDExtensionCTSCT) {
return true
}
return false
}
// OIDInExtensions checks whether the extension identified by oid is present in extensions
// and returns how many times it occurs together with an indication of whether any of them
// are marked critical.
func OIDInExtensions(oid asn1.ObjectIdentifier, extensions []pkix.Extension) (int, bool) {
count := 0
critical := false
for _, ext := range extensions {
if ext.Id.Equal(oid) {
count++
if ext.Critical {
critical = true
}
}
}
return count, critical
}
// String formatting for various X.509/ASN.1 types
func bitStringToString(b asn1.BitString) string {
result := hex.EncodeToString(b.Bytes)
bitsLeft := b.BitLength % 8
if bitsLeft != 0 {
result += " (" + strconv.Itoa(8-bitsLeft) + " unused bits)"
}
return result
}
func publicKeyAlgorithmToString(algo x509.PublicKeyAlgorithm) string {
// Use OpenSSL-compatible strings for the algorithms.
switch algo {
case x509.RSA:
return "rsaEncryption"
case x509.DSA:
return "dsaEncryption"
case x509.ECDSA:
return "id-ecPublicKey"
default:
return strconv.Itoa(int(algo))
}
}
// appendHexData adds a hex dump of binary data to buf, with line breaks
// after each set of count bytes, and with each new line prefixed with the
// given prefix.
func appendHexData(buf *bytes.Buffer, data []byte, count int, prefix string) {
for ii, byte := range data {
if ii%count == 0 {
if ii > 0 {
buf.WriteString("\n")
}
buf.WriteString(prefix)
}
buf.WriteString(fmt.Sprintf("%02x:", byte))
}
}
func curveOIDToString(oid asn1.ObjectIdentifier) (t string, bitlen int) {
switch {
case oid.Equal(x509.OIDNamedCurveP224):
return "secp224r1", 224
case oid.Equal(x509.OIDNamedCurveP256):
return "prime256v1", 256
case oid.Equal(x509.OIDNamedCurveP384):
return "secp384r1", 384
case oid.Equal(x509.OIDNamedCurveP521):
return "secp521r1", 521
case oid.Equal(x509.OIDNamedCurveP192):
return "secp192r1", 192
}
return fmt.Sprintf("%v", oid), -1
}
func publicKeyToString(algo x509.PublicKeyAlgorithm, pub interface{}) string {
var buf bytes.Buffer
switch pub := pub.(type) {
case *rsa.PublicKey:
bitlen := pub.N.BitLen()
buf.WriteString(fmt.Sprintf(" Public Key: (%d bit)\n", bitlen))
buf.WriteString(" Modulus:\n")
data := pub.N.Bytes()
appendHexData(&buf, data, 15, " ")
buf.WriteString("\n")
buf.WriteString(fmt.Sprintf(" Exponent: %d (0x%x)", pub.E, pub.E))
case *dsa.PublicKey:
buf.WriteString(" pub:\n")
appendHexData(&buf, pub.Y.Bytes(), 15, " ")
buf.WriteString("\n")
buf.WriteString(" P:\n")
appendHexData(&buf, pub.P.Bytes(), 15, " ")
buf.WriteString("\n")
buf.WriteString(" Q:\n")
appendHexData(&buf, pub.Q.Bytes(), 15, " ")
buf.WriteString("\n")
buf.WriteString(" G:\n")
appendHexData(&buf, pub.G.Bytes(), 15, " ")
case *ecdsa.PublicKey:
data := elliptic.Marshal(pub.Curve, pub.X, pub.Y)
oid, ok := x509.OIDFromNamedCurve(pub.Curve)
if !ok {
return " <unsupported elliptic curve>"
}
oidname, bitlen := curveOIDToString(oid)
buf.WriteString(fmt.Sprintf(" Public Key: (%d bit)\n", bitlen))
buf.WriteString(" pub:\n")
appendHexData(&buf, data, 15, " ")
buf.WriteString("\n")
buf.WriteString(fmt.Sprintf(" ASN1 OID: %s", oidname))
default:
buf.WriteString(fmt.Sprintf("%v", pub))
}
return buf.String()
}
func commaAppend(buf *bytes.Buffer, s string) {
if buf.Len() > 0 {
buf.WriteString(", ")
}
buf.WriteString(s)
}
func keyUsageToString(k x509.KeyUsage) string {
var buf bytes.Buffer
if k&x509.KeyUsageDigitalSignature != 0 {
commaAppend(&buf, "Digital Signature")
}
if k&x509.KeyUsageContentCommitment != 0 {
commaAppend(&buf, "Content Commitment")
}
if k&x509.KeyUsageKeyEncipherment != 0 {
commaAppend(&buf, "Key Encipherment")
}
if k&x509.KeyUsageDataEncipherment != 0 {
commaAppend(&buf, "Data Encipherment")
}
if k&x509.KeyUsageKeyAgreement != 0 {
commaAppend(&buf, "Key Agreement")
}
if k&x509.KeyUsageCertSign != 0 {
commaAppend(&buf, "Certificate Signing")
}
if k&x509.KeyUsageCRLSign != 0 {
commaAppend(&buf, "CRL Signing")
}
if k&x509.KeyUsageEncipherOnly != 0 {
commaAppend(&buf, "Encipher Only")
}
if k&x509.KeyUsageDecipherOnly != 0 {
commaAppend(&buf, "Decipher Only")
}
return buf.String()
}
func extKeyUsageToString(u x509.ExtKeyUsage) string {
switch u {
case x509.ExtKeyUsageAny:
return "Any"
case x509.ExtKeyUsageServerAuth:
return "TLS Web server authentication"
case x509.ExtKeyUsageClientAuth:
return "TLS Web client authentication"
case x509.ExtKeyUsageCodeSigning:
return "Signing of executable code"
case x509.ExtKeyUsageEmailProtection:
return "Email protection"
case x509.ExtKeyUsageIPSECEndSystem:
return "IPSEC end system"
case x509.ExtKeyUsageIPSECTunnel:
return "IPSEC tunnel"
case x509.ExtKeyUsageIPSECUser:
return "IPSEC user"
case x509.ExtKeyUsageTimeStamping:
return "Time stamping"
case x509.ExtKeyUsageOCSPSigning:
return "OCSP signing"
case x509.ExtKeyUsageMicrosoftServerGatedCrypto:
return "Microsoft server gated cryptography"
case x509.ExtKeyUsageNetscapeServerGatedCrypto:
return "Netscape server gated cryptography"
case x509.ExtKeyUsageCertificateTransparency:
return "Certificate transparency"
default:
return "Unknown"
}
}
func attributeOIDToString(oid asn1.ObjectIdentifier) string {
switch {
case oid.Equal(pkix.OIDCountry):
return "Country"
case oid.Equal(pkix.OIDOrganization):
return "Organization"
case oid.Equal(pkix.OIDOrganizationalUnit):
return "OrganizationalUnit"
case oid.Equal(pkix.OIDCommonName):
return "CommonName"
case oid.Equal(pkix.OIDSerialNumber):
return "SerialNumber"
case oid.Equal(pkix.OIDLocality):
return "Locality"
case oid.Equal(pkix.OIDProvince):
return "Province"
case oid.Equal(pkix.OIDStreetAddress):
return "StreetAddress"
case oid.Equal(pkix.OIDPostalCode):
return "PostalCode"
case oid.Equal(pkix.OIDPseudonym):
return "Pseudonym"
case oid.Equal(pkix.OIDTitle):
return "Title"
case oid.Equal(pkix.OIDDnQualifier):
return "DnQualifier"
case oid.Equal(pkix.OIDName):
return "Name"
case oid.Equal(pkix.OIDSurname):
return "Surname"
case oid.Equal(pkix.OIDGivenName):
return "GivenName"
case oid.Equal(pkix.OIDInitials):
return "Initials"
case oid.Equal(pkix.OIDGenerationQualifier):
return "GenerationQualifier"
default:
return oid.String()
}
}
// NameToString creates a string description of a pkix.Name object.
func NameToString(name pkix.Name) string {
var result bytes.Buffer
addSingle := func(prefix, item string) {
if len(item) == 0 {
return
}
commaAppend(&result, prefix)
result.WriteString(item)
}
addList := func(prefix string, items []string) {
for _, item := range items {
addSingle(prefix, item)
}
}
addList("C=", name.Country)
addList("O=", name.Organization)
addList("OU=", name.OrganizationalUnit)
addList("L=", name.Locality)
addList("ST=", name.Province)
addList("streetAddress=", name.StreetAddress)
addList("postalCode=", name.PostalCode)
addSingle("serialNumber=", name.SerialNumber)
addSingle("CN=", name.CommonName)
for _, atv := range name.Names {
value, ok := atv.Value.(string)
if !ok {
continue
}
t := atv.Type
// All of the defined attribute OIDs are of the form 2.5.4.N, and OIDAttribute is
// the 2.5.4 prefix ('id-at' in RFC 5280).
if len(t) == 4 && t[0] == pkix.OIDAttribute[0] && t[1] == pkix.OIDAttribute[1] && t[2] == pkix.OIDAttribute[2] {
// OID is 'id-at N', so check the final value to figure out which attribute.
switch t[3] {
case pkix.OIDCommonName[3], pkix.OIDSerialNumber[3], pkix.OIDCountry[3], pkix.OIDLocality[3], pkix.OIDProvince[3],
pkix.OIDStreetAddress[3], pkix.OIDOrganization[3], pkix.OIDOrganizationalUnit[3], pkix.OIDPostalCode[3]:
continue // covered by explicit fields
case pkix.OIDPseudonym[3]:
addSingle("pseudonym=", value)
continue
case pkix.OIDTitle[3]:
addSingle("title=", value)
continue
case pkix.OIDDnQualifier[3]:
addSingle("dnQualifier=", value)
continue
case pkix.OIDName[3]:
addSingle("name=", value)
continue
case pkix.OIDSurname[3]:
addSingle("surname=", value)
continue
case pkix.OIDGivenName[3]:
addSingle("givenName=", value)
continue
case pkix.OIDInitials[3]:
addSingle("initials=", value)
continue
case pkix.OIDGenerationQualifier[3]:
addSingle("generationQualifier=", value)
continue
}
}
addSingle(t.String()+"=", value)
}
return result.String()
}
// OtherNameToString creates a string description of an x509.OtherName object.
func OtherNameToString(other x509.OtherName) string {
return fmt.Sprintf("%v=%v", other.TypeID, hex.EncodeToString(other.Value.Bytes))
}
// GeneralNamesToString creates a string description of an x509.GeneralNames object.
func GeneralNamesToString(gname *x509.GeneralNames) string {
var buf bytes.Buffer
for _, name := range gname.DNSNames {
commaAppend(&buf, "DNS:"+name)
}
for _, email := range gname.EmailAddresses {
commaAppend(&buf, "email:"+email)
}
for _, name := range gname.DirectoryNames {
commaAppend(&buf, "DirName:"+NameToString(name))
}
for _, uri := range gname.URIs {
commaAppend(&buf, "URI:"+uri)
}
for _, ip := range gname.IPNets {
if ip.Mask == nil {
commaAppend(&buf, "IP Address:"+ip.IP.String())
} else {
commaAppend(&buf, "IP Address:"+ip.IP.String()+"/"+ip.Mask.String())
}
}
for _, id := range gname.RegisteredIDs {
commaAppend(&buf, "Registered ID:"+id.String())
}
for _, other := range gname.OtherNames {
commaAppend(&buf, "othername:"+OtherNameToString(other))
}
return buf.String()
}
// CertificateToString generates a string describing the given certificate.
// The output roughly resembles that from openssl x509 -text.
func CertificateToString(cert *x509.Certificate) string {
var result bytes.Buffer
result.WriteString(fmt.Sprintf("Certificate:\n"))
result.WriteString(fmt.Sprintf(" Data:\n"))
result.WriteString(fmt.Sprintf(" Version: %d (%#x)\n", cert.Version, cert.Version-1))
result.WriteString(fmt.Sprintf(" Serial Number: %d (%#[1]x)\n", cert.SerialNumber))
result.WriteString(fmt.Sprintf(" Signature Algorithm: %v\n", cert.SignatureAlgorithm))
result.WriteString(fmt.Sprintf(" Issuer: %v\n", NameToString(cert.Issuer)))
result.WriteString(fmt.Sprintf(" Validity:\n"))
result.WriteString(fmt.Sprintf(" Not Before: %v\n", cert.NotBefore))
result.WriteString(fmt.Sprintf(" Not After : %v\n", cert.NotAfter))
result.WriteString(fmt.Sprintf(" Subject: %v\n", NameToString(cert.Subject)))
result.WriteString(fmt.Sprintf(" Subject Public Key Info:\n"))
result.WriteString(fmt.Sprintf(" Public Key Algorithm: %v\n", publicKeyAlgorithmToString(cert.PublicKeyAlgorithm)))
result.WriteString(fmt.Sprintf("%v\n", publicKeyToString(cert.PublicKeyAlgorithm, cert.PublicKey)))
if len(cert.Extensions) > 0 {
result.WriteString(fmt.Sprintf(" X509v3 extensions:\n"))
}
// First display the extensions that are already cracked out
showAuthKeyID(&result, cert)
showSubjectKeyID(&result, cert)
showKeyUsage(&result, cert)
showExtendedKeyUsage(&result, cert)
showBasicConstraints(&result, cert)
showSubjectAltName(&result, cert)
showNameConstraints(&result, cert)
showCertPolicies(&result, cert)
showCRLDPs(&result, cert)
showAuthInfoAccess(&result, cert)
showSubjectInfoAccess(&result, cert)
showRPKIAddressRanges(&result, cert)
showRPKIASIdentifiers(&result, cert)
showCTPoison(&result, cert)
showCTSCT(&result, cert)
showCTLogSTHInfo(&result, cert)
showUnhandledExtensions(&result, cert)
showSignature(&result, cert)
return result.String()
}
func showCritical(result *bytes.Buffer, critical bool) {
if critical {
result.WriteString(" critical")
}
result.WriteString("\n")
}
func showAuthKeyID(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionAuthorityKeyId, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" X509v3 Authority Key Identifier:"))
showCritical(result, critical)
result.WriteString(fmt.Sprintf(" keyid:%v\n", hex.EncodeToString(cert.AuthorityKeyId)))
}
}
func showSubjectKeyID(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionSubjectKeyId, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" X509v3 Subject Key Identifier:"))
showCritical(result, critical)
result.WriteString(fmt.Sprintf(" keyid:%v\n", hex.EncodeToString(cert.SubjectKeyId)))
}
}
func showKeyUsage(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionKeyUsage, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" X509v3 Key Usage:"))
showCritical(result, critical)
result.WriteString(fmt.Sprintf(" %v\n", keyUsageToString(cert.KeyUsage)))
}
}
func showExtendedKeyUsage(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionExtendedKeyUsage, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" X509v3 Extended Key Usage:"))
showCritical(result, critical)
var usages bytes.Buffer
for _, usage := range cert.ExtKeyUsage {
commaAppend(&usages, extKeyUsageToString(usage))
}
for _, oid := range cert.UnknownExtKeyUsage {
commaAppend(&usages, oid.String())
}
result.WriteString(fmt.Sprintf(" %v\n", usages.String()))
}
}
func showBasicConstraints(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionBasicConstraints, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" X509v3 Basic Constraints:"))
showCritical(result, critical)
result.WriteString(fmt.Sprintf(" CA:%t", cert.IsCA))
if cert.MaxPathLen > 0 || cert.MaxPathLenZero {
result.WriteString(fmt.Sprintf(", pathlen:%d", cert.MaxPathLen))
}
result.WriteString(fmt.Sprintf("\n"))
}
}
func showSubjectAltName(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionSubjectAltName, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" X509v3 Subject Alternative Name:"))
showCritical(result, critical)
var buf bytes.Buffer
for _, name := range cert.DNSNames {
commaAppend(&buf, "DNS:"+name)
}
for _, email := range cert.EmailAddresses {
commaAppend(&buf, "email:"+email)
}
for _, ip := range cert.IPAddresses {
commaAppend(&buf, "IP Address:"+ip.String())
}
result.WriteString(fmt.Sprintf(" %v\n", buf.String()))
// TODO(drysdale): include other name forms
}
}
func showNameConstraints(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionNameConstraints, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" X509v3 Name Constraints:"))
showCritical(result, critical)
if len(cert.PermittedDNSDomains) > 0 {
result.WriteString(fmt.Sprintf(" Permitted:\n"))
var buf bytes.Buffer
for _, name := range cert.PermittedDNSDomains {
commaAppend(&buf, "DNS:"+name)
}
result.WriteString(fmt.Sprintf(" %v\n", buf.String()))
}
// TODO(drysdale): include other name forms
}
}
func showCertPolicies(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionCertificatePolicies, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" X509v3 Certificate Policies:"))
showCritical(result, critical)
for _, oid := range cert.PolicyIdentifiers {
result.WriteString(fmt.Sprintf(" Policy: %v\n", oid.String()))
// TODO(drysdale): Display any qualifiers associated with the policy
}
}
}
func showCRLDPs(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionCRLDistributionPoints, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" X509v3 CRL Distribution Points:"))
showCritical(result, critical)
result.WriteString(fmt.Sprintf(" Full Name:\n"))
var buf bytes.Buffer
for _, pt := range cert.CRLDistributionPoints {
commaAppend(&buf, "URI:"+pt)
}
result.WriteString(fmt.Sprintf(" %v\n", buf.String()))
// TODO(drysdale): Display other GeneralNames types, plus issuer/reasons/relative-name
}
}
func showAuthInfoAccess(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionAuthorityInfoAccess, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" Authority Information Access:"))
showCritical(result, critical)
var issuerBuf bytes.Buffer
for _, issuer := range cert.IssuingCertificateURL {
commaAppend(&issuerBuf, "URI:"+issuer)
}
if issuerBuf.Len() > 0 {
result.WriteString(fmt.Sprintf(" CA Issuers - %v\n", issuerBuf.String()))
}
var ocspBuf bytes.Buffer
for _, ocsp := range cert.OCSPServer {
commaAppend(&ocspBuf, "URI:"+ocsp)
}
if ocspBuf.Len() > 0 {
result.WriteString(fmt.Sprintf(" OCSP - %v\n", ocspBuf.String()))
}
// TODO(drysdale): Display other GeneralNames types
}
}
func showSubjectInfoAccess(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionSubjectInfoAccess, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" Subject Information Access:"))
showCritical(result, critical)
var tsBuf bytes.Buffer
for _, ts := range cert.SubjectTimestamps {
commaAppend(&tsBuf, "URI:"+ts)
}
if tsBuf.Len() > 0 {
result.WriteString(fmt.Sprintf(" AD Time Stamping - %v\n", tsBuf.String()))
}
var repoBuf bytes.Buffer
for _, repo := range cert.SubjectCARepositories {
commaAppend(&repoBuf, "URI:"+repo)
}
if repoBuf.Len() > 0 {
result.WriteString(fmt.Sprintf(" CA repository - %v\n", repoBuf.String()))
}
}
}
func showAddressRange(prefix x509.IPAddressPrefix, afi uint16) string {
switch afi {
case x509.IPv4AddressFamilyIndicator, x509.IPv6AddressFamilyIndicator:
size := 4
if afi == x509.IPv6AddressFamilyIndicator {
size = 16
}
ip := make([]byte, size)
copy(ip, prefix.Bytes)
addr := net.IPNet{IP: ip, Mask: net.CIDRMask(prefix.BitLength, 8*size)}
return addr.String()
default:
return fmt.Sprintf("%x/%d", prefix.Bytes, prefix.BitLength)
}
}
func showRPKIAddressRanges(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionIPPrefixList, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" sbgp-ipAddrBlock:"))
showCritical(result, critical)
for _, blocks := range cert.RPKIAddressRanges {
afi := blocks.AFI
switch afi {
case x509.IPv4AddressFamilyIndicator:
result.WriteString(" IPv4")
case x509.IPv6AddressFamilyIndicator:
result.WriteString(" IPv6")
default:
result.WriteString(fmt.Sprintf(" %d", afi))
}
if blocks.SAFI != 0 {
result.WriteString(fmt.Sprintf(" SAFI=%d", blocks.SAFI))
}
result.WriteString(":")
if blocks.InheritFromIssuer {
result.WriteString(" inherit\n")
continue
}
result.WriteString("\n")
for _, prefix := range blocks.AddressPrefixes {
result.WriteString(fmt.Sprintf(" %s\n", showAddressRange(prefix, afi)))
}
for _, ipRange := range blocks.AddressRanges {
result.WriteString(fmt.Sprintf(" [%s, %s]\n", showAddressRange(ipRange.Min, afi), showAddressRange(ipRange.Max, afi)))
}
}
}
}
func showASIDs(result *bytes.Buffer, asids *x509.ASIdentifiers, label string) {
if asids == nil {
return
}
result.WriteString(fmt.Sprintf(" %s:\n", label))
if asids.InheritFromIssuer {
result.WriteString(" inherit\n")
return
}
for _, id := range asids.ASIDs {
result.WriteString(fmt.Sprintf(" %d\n", id))
}
for _, idRange := range asids.ASIDRanges {
result.WriteString(fmt.Sprintf(" %d-%d\n", idRange.Min, idRange.Max))
}
}
func showRPKIASIdentifiers(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionASList, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" sbgp-autonomousSysNum:"))
showCritical(result, critical)
showASIDs(result, cert.RPKIASNumbers, "Autonomous System Numbers")
showASIDs(result, cert.RPKIRoutingDomainIDs, "Routing Domain Identifiers")
}
}
func showCTPoison(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionCTPoison, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" RFC6962 Pre-Certificate Poison:"))
showCritical(result, critical)
result.WriteString(" .....\n")
}
}
func showCTSCT(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509.OIDExtensionCTSCT, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" RFC6962 Certificate Transparency SCT:"))
showCritical(result, critical)
for i, sctData := range cert.SCTList.SCTList {
result.WriteString(fmt.Sprintf(" SCT [%d]:\n", i))
var sct ct.SignedCertificateTimestamp
_, err := tls.Unmarshal(sctData.Val, &sct)
if err != nil {
appendHexData(result, sctData.Val, 16, " ")
result.WriteString("\n")
continue
}
result.WriteString(fmt.Sprintf(" Version: %d\n", sct.SCTVersion))
result.WriteString(fmt.Sprintf(" LogID: %s\n", base64.StdEncoding.EncodeToString(sct.LogID.KeyID[:])))
result.WriteString(fmt.Sprintf(" Timestamp: %d\n", sct.Timestamp))
result.WriteString(fmt.Sprintf(" Signature: %s\n", sct.Signature.Algorithm))
result.WriteString(fmt.Sprintf(" Signature:\n"))
appendHexData(result, sct.Signature.Signature, 16, " ")
result.WriteString("\n")
}
}
}
func showCTLogSTHInfo(result *bytes.Buffer, cert *x509.Certificate) {
count, critical := OIDInExtensions(x509ext.OIDExtensionCTSTH, cert.Extensions)
if count > 0 {
result.WriteString(fmt.Sprintf(" Certificate Transparency STH:"))
showCritical(result, critical)
sthInfo, err := x509ext.LogSTHInfoFromCert(cert)
if err != nil {
result.WriteString(fmt.Sprintf(" Failed to decode STH:\n"))
return
}
result.WriteString(fmt.Sprintf(" LogURL: %s\n", string(sthInfo.LogURL)))
result.WriteString(fmt.Sprintf(" Version: %d\n", sthInfo.Version))
result.WriteString(fmt.Sprintf(" TreeSize: %d\n", sthInfo.TreeSize))
result.WriteString(fmt.Sprintf(" Timestamp: %d\n", sthInfo.Timestamp))
result.WriteString(fmt.Sprintf(" RootHash:\n"))
appendHexData(result, sthInfo.SHA256RootHash[:], 16, " ")
result.WriteString("\n")
result.WriteString(fmt.Sprintf(" TreeHeadSignature: %s\n", sthInfo.TreeHeadSignature.Algorithm))
result.WriteString(fmt.Sprintf(" TreeHeadSignature:\n"))
appendHexData(result, sthInfo.TreeHeadSignature.Signature, 16, " ")
result.WriteString("\n")
}
}
func showUnhandledExtensions(result *bytes.Buffer, cert *x509.Certificate) {
for _, ext := range cert.Extensions {
// Skip extensions that are already cracked out
if oidAlreadyPrinted(ext.Id) {
continue
}
result.WriteString(fmt.Sprintf(" %v:", ext.Id))
showCritical(result, ext.Critical)
appendHexData(result, ext.Value, 16, " ")
result.WriteString("\n")
}
}
func showSignature(result *bytes.Buffer, cert *x509.Certificate) {
result.WriteString(fmt.Sprintf(" Signature Algorithm: %v\n", cert.SignatureAlgorithm))
appendHexData(result, cert.Signature, 18, " ")
result.WriteString("\n")
}
// TODO(drysdale): remove this once all standard OIDs are parsed and printed.
func oidAlreadyPrinted(oid asn1.ObjectIdentifier) bool {
if oid.Equal(x509.OIDExtensionSubjectKeyId) ||
oid.Equal(x509.OIDExtensionKeyUsage) ||
oid.Equal(x509.OIDExtensionExtendedKeyUsage) ||
oid.Equal(x509.OIDExtensionAuthorityKeyId) ||
oid.Equal(x509.OIDExtensionBasicConstraints) ||
oid.Equal(x509.OIDExtensionSubjectAltName) ||
oid.Equal(x509.OIDExtensionCertificatePolicies) ||
oid.Equal(x509.OIDExtensionNameConstraints) ||
oid.Equal(x509.OIDExtensionCRLDistributionPoints) ||
oid.Equal(x509.OIDExtensionAuthorityInfoAccess) ||
oid.Equal(x509.OIDExtensionSubjectInfoAccess) ||
oid.Equal(x509.OIDExtensionIPPrefixList) ||
oid.Equal(x509.OIDExtensionASList) ||
oid.Equal(x509.OIDExtensionCTPoison) ||
oid.Equal(x509.OIDExtensionCTSCT) ||
oid.Equal(x509ext.OIDExtensionCTSTH) {
return true
}
return false
}
// CertificateFromPEM takes a certificate in PEM format and returns the
// corresponding x509.Certificate object.
func CertificateFromPEM(pemBytes []byte) (*x509.Certificate, error) {
block, rest := pem.Decode(pemBytes)
if len(rest) != 0 {
return nil, errors.New("trailing data found after PEM block")
}
if block == nil {
return nil, errors.New("PEM block is nil")
}
if block.Type != "CERTIFICATE" {
return nil, errors.New("PEM block is not a CERTIFICATE")
}
return x509.ParseCertificate(block.Bytes)
}
// CertificatesFromPEM parses one or more certificates from the given PEM data.
// The PEM certificates must be concatenated. This function can be used for
// parsing PEM-formatted certificate chains, but does not verify that the
// resulting chain is a valid certificate chain.
func CertificatesFromPEM(pemBytes []byte) ([]*x509.Certificate, error) {
var chain []*x509.Certificate
for {
var block *pem.Block
block, pemBytes = pem.Decode(pemBytes)
if block == nil {
return chain, nil
}
if block.Type != "CERTIFICATE" {
return nil, fmt.Errorf("PEM block is not a CERTIFICATE")
}
cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
return nil, errors.New("failed to parse certificate")
}
chain = append(chain, cert)
}
}
// ParseSCTsFromSCTList parses each of the SCTs contained within an SCT list.
func ParseSCTsFromSCTList(sctList *x509.SignedCertificateTimestampList) ([]*ct.SignedCertificateTimestamp, error) {
var scts []*ct.SignedCertificateTimestamp
for i, data := range sctList.SCTList {
sct, err := ExtractSCT(&data)
if err != nil {
return nil, fmt.Errorf("error extracting SCT number %d: %s", i, err)
}
scts = append(scts, sct)
}
return scts, nil
}
// ExtractSCT deserializes an SCT from a TLS-encoded SCT.
func ExtractSCT(sctData *x509.SerializedSCT) (*ct.SignedCertificateTimestamp, error) {
if sctData == nil {
return nil, errors.New("SCT is nil")
}
var sct ct.SignedCertificateTimestamp
if rest, err := tls.Unmarshal(sctData.Val, &sct); err != nil {
return nil, fmt.Errorf("error parsing SCT: %s", err)
} else if len(rest) > 0 {
return nil, fmt.Errorf("extra data (%d bytes) after serialized SCT", len(rest))
}
return &sct, nil
}
var pemCertificatePrefix = []byte("-----BEGIN CERTIFICATE")
// ParseSCTsFromCertificate parses any SCTs that are embedded in the
// certificate provided. The certificate bytes provided can be either DER or
// PEM, provided the PEM data starts with the PEM block marker (i.e. has no
// leading text).
func ParseSCTsFromCertificate(certBytes []byte) ([]*ct.SignedCertificateTimestamp, error) {
var cert *x509.Certificate
var err error
if bytes.HasPrefix(certBytes, pemCertificatePrefix) {
cert, err = CertificateFromPEM(certBytes)
} else {
cert, err = x509.ParseCertificate(certBytes)
}
if err != nil {
return nil, fmt.Errorf("failed to parse certificate: %s", err)
}
return ParseSCTsFromSCTList(&cert.SCTList)
}