Merge pull request #3384 from dougm/thumbprint-sha256

Add support for SHA256 thumbprint based vCenter authentication

govc/about/cert.go

@@ -89,7 +89,7 @@ func (r *certResult) Write(w io.Writer) error {
 
 	if r.cmd.thumbprint {
 		u := r.cmd.Session.URL
-		_, err := fmt.Fprintf(w, "%s %s\n", u.Host, r.info.ThumbprintSHA1)
+		_, err := fmt.Fprintf(w, "%s %s\n", u.Host, r.info.ThumbprintSHA256)
 		return err
 	}
 

govc/test/cli.bats

@@ -59,7 +59,7 @@ load test_helper
   run govc about.cert -show
   assert_success
 
-  # with -k=true we get thumbprint output and exit 0
+  # with -k=true we get sha256 thumbprint output and exit 0
   thumbprint=$(govc about.cert -k=true -thumbprint)
 
   # with -k=true we get thumbprint output and exit 60
@@ -77,6 +77,12 @@ load test_helper
 
   run govc about -k=false -tls-known-hosts <(echo "nope nope")
   assert_failure
+
+  # sha1 backwards compatibility
+  host=$(awk '{print $1}'<<<"$thumbprint")
+  sha1=$(govc about.cert -k=true -json | jq -r .thumbprintSHA1)
+  run govc about -k=false -tls-known-hosts <(echo "$host $sha1")
+  assert_success
 }
 
 @test "version" {

object/host_certificate_info.go

@@ -17,7 +17,6 @@ limitations under the License.
 package object
 
 import (
-	"crypto/sha256"
 	"crypto/tls"
 	"crypto/x509"
 	"crypto/x509/pkix"
@@ -58,14 +57,7 @@ func (info *HostCertificateInfo) FromCertificate(cert *x509.Certificate) *HostCe
 	info.Subject = info.fromName(info.subjectName)
 
 	info.ThumbprintSHA1 = soap.ThumbprintSHA1(cert)
-
-	// SHA-256 for info purposes only, API fields all use SHA-1
-	sum := sha256.Sum256(cert.Raw)
-	hex := make([]string, len(sum))
-	for i, b := range sum {
-		hex[i] = fmt.Sprintf("%02X", b)
-	}
-	info.ThumbprintSHA256 = strings.Join(hex, ":")
+	info.ThumbprintSHA256 = soap.ThumbprintSHA256(cert)
 
 	if info.Status == "" {
 		info.Status = string(types.HostCertificateManagerCertificateInfoCertificateStatusUnknown)

vim25/soap/client.go

@@ -21,6 +21,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/sha1"
+	"crypto/sha256"
 	"crypto/tls"
 	"crypto/x509"
 	"encoding/json"
@@ -387,6 +388,20 @@ func ThumbprintSHA1(cert *x509.Certificate) string {
 	return strings.Join(hex, ":")
 }
 
+// ThumbprintSHA256 returns the sha256 thumbprint of the given cert.
+func ThumbprintSHA256(cert *x509.Certificate) string {
+	sum := sha256.Sum256(cert.Raw)
+	hex := make([]string, len(sum))
+	for i, b := range sum {
+		hex[i] = fmt.Sprintf("%02X", b)
+	}
+	return strings.Join(hex, ":")
+}
+
+func thumbprintMatches(thumbprint string, cert *x509.Certificate) bool {
+	return thumbprint == ThumbprintSHA256(cert) || thumbprint == ThumbprintSHA1(cert)
+}
+
 func (c *Client) dialTLSContext(
 	ctx context.Context,
 	network, addr string) (net.Conn, error) {
@@ -418,14 +433,13 @@ func (c *Client) dialTLSContext(
 	}
 
 	cert := conn.ConnectionState().PeerCertificates[0]
-	peer := ThumbprintSHA1(cert)
-	if thumbprint != peer {
-		_ = conn.Close()
-
-		return nil, fmt.Errorf("host %q thumbprint does not match %q", addr, thumbprint)
+	if thumbprintMatches(thumbprint, cert) {
+		return conn, nil
 	}
 
-	return conn, nil
+	_ = conn.Close()
+
+	return nil, fmt.Errorf("host %q thumbprint does not match %q", addr, thumbprint)
 }
 
 // splitHostPort is similar to net.SplitHostPort,