1 files changed, 229 insertions, 0 deletions
diff --git a/src/crypto/x509/root_windows.go b/src/crypto/x509/root_windows.go
new file mode 100644
index 000000000..81018b78f
--- /dev/null
+++ b/src/crypto/x509/root_windows.go
@@ -0,0 +1,229 @@
+// 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 _, intermediate := range opts.Intermediates.certs {
+			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))[:]
+	lastChain := simpleChains[count-1]
+	elements := (*[1 << 20]*syscall.CertChainElement)(unsafe.Pointer(lastChain.Elements))[:]
+	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))[:]
+		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}
+		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: uintptr(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
+}
+
+// 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) {
+	hasDNSName := opts != nil && len(opts.DNSName) > 0
+
+	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))
+
+	// If there's a DNSName set in opts, assume we're verifying
+	// a certificate from a TLS server.
+	if hasDNSName {
+		oids := []*byte{
+			&syscall.OID_PKIX_KP_SERVER_AUTH[0],
+			// Both IE and Chrome allow certificates with
+			// Server Gated Crypto as well. Some certificates
+			// in the wild require them.
+			&syscall.OID_SERVER_GATED_CRYPTO[0],
+			&syscall.OID_SGC_NETSCAPE[0],
+		}
+		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
+	}
+
+	// CertGetCertificateChain will traverse Windows's root stores
+	// in an attempt to build a verified certificate chain.  Once
+	// it has found a verified chain, it stops. MSDN docs on
+	// CERT_CHAIN_CONTEXT:
+	//
+	//   When a CERT_CHAIN_CONTEXT is built, the first simple chain
+	//   begins with an end certificate and ends with a self-signed
+	//   certificate. If that self-signed certificate is not a root
+	//   or otherwise trusted certificate, an attempt is made to
+	//   build a new chain. CTLs are used to create the new chain
+	//   beginning with the self-signed certificate from the original
+	//   chain as the end certificate of the new chain. This process
+	//   continues building additional simple chains until the first
+	//   self-signed certificate is a trusted certificate or until
+	//   an additional simple chain cannot be built.
+	//
+	// The result is that we'll only get a single trusted chain to
+	// return to our caller.
+	var chainCtx *syscall.CertChainContext
+	err = syscall.CertGetCertificateChain(syscall.Handle(0), storeCtx, verifyTime, storeCtx.Store, para, 0, 0, &chainCtx)
+	if err != nil {
+		return nil, err
+	}
+	defer syscall.CertFreeCertificateChain(chainCtx)
+
+	err = checkChainTrustStatus(c, chainCtx)
+	if err != nil {
+		return nil, err
+	}
+
+	if hasDNSName {
+		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
+	}
+
+	chains = append(chains, chain)
+
+	return chains, nil
+}
+
+func initSystemRoots() {
+}