[FAB-9605] Export list of default cipher suites

Change-Id: Ie4f1c745bddc1126fbc47c517b8b465e2c3f171e
Signed-off-by: Kostas Christidis <[email protected]>

core/comm/config.go

@@ -14,6 +14,7 @@ import (
 	"google.golang.org/grpc/keepalive"
 )
 
+// Configuration defaults
 var (
 	// Max send and receive bytes for grpc clients and servers
 	MaxRecvMsgSize = 100 * 1024 * 1024
@@ -27,7 +28,7 @@ var (
 		ServerMinInterval: time.Duration(1) * time.Minute,  // match ClientInterval
 	}
 	// strong TLS cipher suites
-	tlsCipherSuites = []uint16{
+	DefaultTLSCipherSuites = []uint16{
 		tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
 		tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
 		tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
@@ -62,7 +63,7 @@ type ClientConfig struct {
 }
 
 // SecureOptions defines the security parameters (e.g. TLS) for a
-// GRPCServer instance
+// GRPCServer or GRPCClient instance
 type SecureOptions struct {
 	// PEM-encoded X509 public key to be used for TLS communication
 	Certificate []byte
@@ -82,7 +83,7 @@ type SecureOptions struct {
 	CipherSuites []uint16
 }
 
-// KeepAliveOptions is used to set the gRPC keepalive settings for both
+// KeepaliveOptions is used to set the gRPC keepalive settings for both
 // clients and servers
 type KeepaliveOptions struct {
 	// ClientInterval is the duration after which if the client does not see

core/comm/server.go

@@ -79,7 +79,7 @@ func NewGRPCServerFromListener(listener net.Listener, serverConfig ServerConfig)
 
 			//set up our TLS config
 			if len(secureConfig.CipherSuites) == 0 {
-				secureConfig.CipherSuites = tlsCipherSuites
+				secureConfig.CipherSuites = DefaultTLSCipherSuites
 			}
 			getCert := func(_ *tls.ClientHelloInfo) (*tls.Certificate, error) {
 				cert := grpcServer.serverCertificate.Load().(tls.Certificate)