Current File : //usr/local/go/src/crypto/x509/root_windows.go
// Copyright 2012 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
import (
"errors"
"syscall"
"unsafe"
)
// Creates a new *syscall.CertContext representing the leaf certificate in an in-memory
// certificate store containing itself and all of the intermediate certificates specified
// in the opts.Intermediates CertPool.
//
// A pointer to the in-memory store is available in the returned CertContext's Store field.
// The store is automatically freed when the CertContext is freed using
// syscall.CertFreeCertificateContext.
func createStoreContext(leaf *Certificate, opts *VerifyOptions) (*syscall.CertContext, error) {
var storeCtx *syscall.CertContext
leafCtx, err := syscall.CertCreateCertificateContext(syscall.X509_ASN_ENCODING|syscall.PKCS_7_ASN_ENCODING, &leaf.Raw[0], uint32(len(leaf.Raw)))
if err != nil {
return nil, err
}
defer syscall.CertFreeCertificateContext(leafCtx)
handle, err := syscall.CertOpenStore(syscall.CERT_STORE_PROV_MEMORY, 0, 0, syscall.CERT_STORE_DEFER_CLOSE_UNTIL_LAST_FREE_FLAG, 0)
if err != nil {
return nil, err
}
defer syscall.CertCloseStore(handle, 0)
err = syscall.CertAddCertificateContextToStore(handle, leafCtx, syscall.CERT_STORE_ADD_ALWAYS, &storeCtx)
if err != nil {
return nil, err
}
if opts.Intermediates != nil {
for i := 0; i < opts.Intermediates.len(); i++ {
intermediate, err := opts.Intermediates.cert(i)
if err != nil {
return nil, err
}
ctx, err := syscall.CertCreateCertificateContext(syscall.X509_ASN_ENCODING|syscall.PKCS_7_ASN_ENCODING, &intermediate.Raw[0], uint32(len(intermediate.Raw)))
if err != nil {
return nil, err
}
err = syscall.CertAddCertificateContextToStore(handle, ctx, syscall.CERT_STORE_ADD_ALWAYS, nil)
syscall.CertFreeCertificateContext(ctx)
if err != nil {
return nil, err
}
}
}
return storeCtx, nil
}
// extractSimpleChain extracts the final certificate chain from a CertSimpleChain.
func extractSimpleChain(simpleChain **syscall.CertSimpleChain, count int) (chain []*Certificate, err error) {
if simpleChain == nil || count == 0 {
return nil, errors.New("x509: invalid simple chain")
}
simpleChains := (*[1 << 20]*syscall.CertSimpleChain)(unsafe.Pointer(simpleChain))[:count:count]
lastChain := simpleChains[count-1]
elements := (*[1 << 20]*syscall.CertChainElement)(unsafe.Pointer(lastChain.Elements))[:lastChain.NumElements:lastChain.NumElements]
for i := 0; i < int(lastChain.NumElements); i++ {
// Copy the buf, since ParseCertificate does not create its own copy.
cert := elements[i].CertContext
encodedCert := (*[1 << 20]byte)(unsafe.Pointer(cert.EncodedCert))[:cert.Length:cert.Length]
buf := make([]byte, cert.Length)
copy(buf, encodedCert)
parsedCert, err := ParseCertificate(buf)
if err != nil {
return nil, err
}
chain = append(chain, parsedCert)
}
return chain, nil
}
// checkChainTrustStatus checks the trust status of the certificate chain, translating
// any errors it finds into Go errors in the process.
func checkChainTrustStatus(c *Certificate, chainCtx *syscall.CertChainContext) error {
if chainCtx.TrustStatus.ErrorStatus != syscall.CERT_TRUST_NO_ERROR {
status := chainCtx.TrustStatus.ErrorStatus
switch status {
case syscall.CERT_TRUST_IS_NOT_TIME_VALID:
return CertificateInvalidError{c, Expired, ""}
case syscall.CERT_TRUST_IS_NOT_VALID_FOR_USAGE:
return CertificateInvalidError{c, IncompatibleUsage, ""}
// TODO(filippo): surface more error statuses.
default:
return UnknownAuthorityError{c, nil, nil}
}
}
return nil
}
// checkChainSSLServerPolicy checks that the certificate chain in chainCtx is valid for
// use as a certificate chain for a SSL/TLS server.
func checkChainSSLServerPolicy(c *Certificate, chainCtx *syscall.CertChainContext, opts *VerifyOptions) error {
servernamep, err := syscall.UTF16PtrFromString(opts.DNSName)
if err != nil {
return err
}
sslPara := &syscall.SSLExtraCertChainPolicyPara{
AuthType: syscall.AUTHTYPE_SERVER,
ServerName: servernamep,
}
sslPara.Size = uint32(unsafe.Sizeof(*sslPara))
para := &syscall.CertChainPolicyPara{
ExtraPolicyPara: (syscall.Pointer)(unsafe.Pointer(sslPara)),
}
para.Size = uint32(unsafe.Sizeof(*para))
status := syscall.CertChainPolicyStatus{}
err = syscall.CertVerifyCertificateChainPolicy(syscall.CERT_CHAIN_POLICY_SSL, chainCtx, para, &status)
if err != nil {
return err
}
// TODO(mkrautz): use the lChainIndex and lElementIndex fields
// of the CertChainPolicyStatus to provide proper context, instead
// using c.
if status.Error != 0 {
switch status.Error {
case syscall.CERT_E_EXPIRED:
return CertificateInvalidError{c, Expired, ""}
case syscall.CERT_E_CN_NO_MATCH:
return HostnameError{c, opts.DNSName}
case syscall.CERT_E_UNTRUSTEDROOT:
return UnknownAuthorityError{c, nil, nil}
default:
return UnknownAuthorityError{c, nil, nil}
}
}
return nil
}
// windowsExtKeyUsageOIDs are the C NUL-terminated string representations of the
// OIDs for use with the Windows API.
var windowsExtKeyUsageOIDs = make(map[ExtKeyUsage][]byte, len(extKeyUsageOIDs))
func init() {
for _, eku := range extKeyUsageOIDs {
windowsExtKeyUsageOIDs[eku.extKeyUsage] = []byte(eku.oid.String() + "\x00")
}
}
func verifyChain(c *Certificate, chainCtx *syscall.CertChainContext, opts *VerifyOptions) (chain []*Certificate, err error) {
err = checkChainTrustStatus(c, chainCtx)
if err != nil {
return nil, err
}
if opts != nil && len(opts.DNSName) > 0 {
err = checkChainSSLServerPolicy(c, chainCtx, opts)
if err != nil {
return nil, err
}
}
chain, err = extractSimpleChain(chainCtx.Chains, int(chainCtx.ChainCount))
if err != nil {
return nil, err
}
if len(chain) == 0 {
return nil, errors.New("x509: internal error: system verifier returned an empty chain")
}
// Mitigate CVE-2020-0601, where the Windows system verifier might be
// tricked into using custom curve parameters for a trusted root, by
// double-checking all ECDSA signatures. If the system was tricked into
// using spoofed parameters, the signature will be invalid for the correct
// ones we parsed. (We don't support custom curves ourselves.)
for i, parent := range chain[1:] {
if parent.PublicKeyAlgorithm != ECDSA {
continue
}
if err := parent.CheckSignature(chain[i].SignatureAlgorithm,
chain[i].RawTBSCertificate, chain[i].Signature); err != nil {
return nil, err
}
}
return chain, nil
}
// systemVerify is like Verify, except that it uses CryptoAPI calls
// to build certificate chains and verify them.
func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
storeCtx, err := createStoreContext(c, opts)
if err != nil {
return nil, err
}
defer syscall.CertFreeCertificateContext(storeCtx)
para := new(syscall.CertChainPara)
para.Size = uint32(unsafe.Sizeof(*para))
keyUsages := opts.KeyUsages
if len(keyUsages) == 0 {
keyUsages = []ExtKeyUsage{ExtKeyUsageServerAuth}
}
oids := make([]*byte, 0, len(keyUsages))
for _, eku := range keyUsages {
if eku == ExtKeyUsageAny {
oids = nil
break
}
if oid, ok := windowsExtKeyUsageOIDs[eku]; ok {
oids = append(oids, &oid[0])
}
// Like the standard verifier, accept SGC EKUs as equivalent to ServerAuth.
if eku == ExtKeyUsageServerAuth {
oids = append(oids, &syscall.OID_SERVER_GATED_CRYPTO[0])
oids = append(oids, &syscall.OID_SGC_NETSCAPE[0])
}
}
if oids != nil {
para.RequestedUsage.Type = syscall.USAGE_MATCH_TYPE_OR
para.RequestedUsage.Usage.Length = uint32(len(oids))
para.RequestedUsage.Usage.UsageIdentifiers = &oids[0]
} else {
para.RequestedUsage.Type = syscall.USAGE_MATCH_TYPE_AND
para.RequestedUsage.Usage.Length = 0
para.RequestedUsage.Usage.UsageIdentifiers = nil
}
var verifyTime *syscall.Filetime
if opts != nil && !opts.CurrentTime.IsZero() {
ft := syscall.NsecToFiletime(opts.CurrentTime.UnixNano())
verifyTime = &ft
}
// The default is to return only the highest quality chain,
// setting this flag will add additional lower quality contexts.
// These are returned in the LowerQualityChains field.
const CERT_CHAIN_RETURN_LOWER_QUALITY_CONTEXTS = 0x00000080
// CertGetCertificateChain will traverse Windows's root stores in an attempt to build a verified certificate chain
var topCtx *syscall.CertChainContext
err = syscall.CertGetCertificateChain(syscall.Handle(0), storeCtx, verifyTime, storeCtx.Store, para, CERT_CHAIN_RETURN_LOWER_QUALITY_CONTEXTS, 0, &topCtx)
if err != nil {
return nil, err
}
defer syscall.CertFreeCertificateChain(topCtx)
chain, topErr := verifyChain(c, topCtx, opts)
if topErr == nil {
chains = append(chains, chain)
}
if lqCtxCount := topCtx.LowerQualityChainCount; lqCtxCount > 0 {
lqCtxs := (*[1 << 20]*syscall.CertChainContext)(unsafe.Pointer(topCtx.LowerQualityChains))[:lqCtxCount:lqCtxCount]
for _, ctx := range lqCtxs {
chain, err := verifyChain(c, ctx, opts)
if err == nil {
chains = append(chains, chain)
}
}
}
if len(chains) == 0 {
// Return the error from the highest quality context.
return nil, topErr
}
return chains, nil
}
func loadSystemRoots() (*CertPool, error) {
// TODO: restore this functionality on Windows. We tried to do
// it in Go 1.8 but had to revert it. See Issue 18609.
// Returning (nil, nil) was the old behavior, prior to CL 30578.
// The if statement here avoids vet complaining about
// unreachable code below.
if true {
return nil, nil
}
const CRYPT_E_NOT_FOUND = 0x80092004
store, err := syscall.CertOpenSystemStore(0, syscall.StringToUTF16Ptr("ROOT"))
if err != nil {
return nil, err
}
defer syscall.CertCloseStore(store, 0)
roots := NewCertPool()
var cert *syscall.CertContext
for {
cert, err = syscall.CertEnumCertificatesInStore(store, cert)
if err != nil {
if errno, ok := err.(syscall.Errno); ok {
if errno == CRYPT_E_NOT_FOUND {
break
}
}
return nil, err
}
if cert == nil {
break
}
// Copy the buf, since ParseCertificate does not create its own copy.
buf := (*[1 << 20]byte)(unsafe.Pointer(cert.EncodedCert))[:cert.Length:cert.Length]
buf2 := make([]byte, cert.Length)
copy(buf2, buf)
if c, err := ParseCertificate(buf2); err == nil {
roots.AddCert(c)
}
}
return roots, nil
}
Mini Shell