http2: add additional blacklisted ciphersuites

TLS_RSA_WITH_AES_128_GCM_SHA256 and TLS_RSA_WITH_AES_256_GCM_SHA384
are also blacklisted in RFC 7540 Appendix A.

Because they are were implemented in Go 1.6, the isBadCipher
function has been moved into the version-tagged files so that the
repo doesn't break for Go 1.5 users.

Change-Id: If8ca058ede51e9a4a337ce8d645cfd9f370d49b4
Reviewed-on: https://go-review.googlesource.com/24214
Reviewed-by: Adam Langley <agl@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

http2/go16.go

@@ -7,6 +7,7 @@
 package http2
 
 import (
+	"crypto/tls"
 	"net/http"
 	"time"
 )
@@ -14,3 +15,29 @@ import (
 func transportExpectContinueTimeout(t1 *http.Transport) time.Duration {
 	return t1.ExpectContinueTimeout
 }
+
+// isBadCipher reports whether the cipher is blacklisted by the HTTP/2 spec.
+func isBadCipher(cipher uint16) bool {
+	switch cipher {
+	case tls.TLS_RSA_WITH_RC4_128_SHA,
+		tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_256_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_128_GCM_SHA256,
+		tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
+		tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+		tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
+		// Reject cipher suites from Appendix A.
+		// "This list includes those cipher suites that do not
+		// offer an ephemeral key exchange and those that are
+		// based on the TLS null, stream or block cipher type"
+		return true
+	default:
+		return false
+	}
+}

http2/not_go16.go

@@ -7,6 +7,7 @@
 package http2
 
 import (
+	"crypto/tls"
 	"net/http"
 	"time"
 )
@@ -17,4 +18,29 @@ func configureTransport(t1 *http.Transport) (*Transport, error) {
 
 func transportExpectContinueTimeout(t1 *http.Transport) time.Duration {
 	return 0
+
+}
+
+// isBadCipher reports whether the cipher is blacklisted by the HTTP/2 spec.
+func isBadCipher(cipher uint16) bool {
+	switch cipher {
+	case tls.TLS_RSA_WITH_RC4_128_SHA,
+		tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_256_CBC_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+		tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
+		// Reject cipher suites from Appendix A.
+		// "This list includes those cipher suites that do not
+		// offer an ephemeral key exchange and those that are
+		// based on the TLS null, stream or block cipher type"
+		return true
+	default:
+		return false
+	}
 }

http2/server.go

@@ -339,30 +339,6 @@ func (s *Server) ServeConn(c net.Conn, opts *ServeConnOpts) {
 	sc.serve()
 }
 
-// isBadCipher reports whether the cipher is blacklisted by the HTTP/2 spec.
-func isBadCipher(cipher uint16) bool {
-	switch cipher {
-	case tls.TLS_RSA_WITH_RC4_128_SHA,
-		tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
-		tls.TLS_RSA_WITH_AES_128_CBC_SHA,
-		tls.TLS_RSA_WITH_AES_256_CBC_SHA,
-		tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
-		tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
-		tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
-		tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
-		tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
-		tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
-		tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
-		// Reject cipher suites from Appendix A.
-		// "This list includes those cipher suites that do not
-		// offer an ephemeral key exchange and those that are
-		// based on the TLS null, stream or block cipher type"
-		return true
-	default:
-		return false
-	}
-}
-
 func (sc *serverConn) rejectConn(err ErrCode, debug string) {
 	sc.vlogf("http2: server rejecting conn: %v, %s", err, debug)
 	// ignoring errors. hanging up anyway.