Added server support for ECDHE key exchange

diff --git a/src/libtls/tls_server.c b/src/libtls/tls_server.c
index 64bda5d1886678a08df6b09a49e81e189134969b..48ab58b9b9f859161c456428aeb577122a4a301c 100644 (file)
--- a/src/libtls/tls_server.c
+++ b/src/libtls/tls_server.c
@@ -341,11 +341,25 @@ static status_t process_key_exchange_dhe(private_tls_server_t *this,
                                                                                 tls_reader_t *reader)
 {
        chunk_t premaster, pub;
+       bool ec = FALSE;
 
        this->crypto->append_handshake(this->crypto,
                                                                   TLS_CLIENT_KEY_EXCHANGE, reader->peek(reader));
 
-       if (!reader->read_data16(reader, &pub))
+       switch (this->dh->get_dh_group(this->dh))
+       {
+               case ECP_256_BIT:
+               case ECP_384_BIT:
+               case ECP_521_BIT:
+               case ECP_192_BIT:
+               case ECP_224_BIT:
+                       ec = TRUE;
+                       break;
+               default:
+                       break;
+       }
+       if ((ec && !reader->read_data8(reader, &pub)) ||
+               (!ec && !reader->read_data16(reader, &pub)))
        {
                DBG1(DBG_TLS, "received invalid Client Key Exchange");
                this->alert->add(this->alert, TLS_FATAL, TLS_DECODE_ERROR);
@@ -672,17 +686,9 @@ static status_t send_server_key_exchange(private_tls_server_t *this,
                                                        tls_handshake_type_t *type, tls_writer_t *writer,
                                                        diffie_hellman_group_t group)
 {
-       diffie_hellman_params_t *params;
+       diffie_hellman_params_t *params = NULL;
        chunk_t chunk;
 
-       params = diffie_hellman_get_params(group);
-       if (!params)
-       {
-               DBG1(DBG_TLS, "no parameters found for DH group %N",
-                        diffie_hellman_group_names, group);
-               this->alert->add(this->alert, TLS_FATAL, TLS_INTERNAL_ERROR);
-               return NEED_MORE;
-       }
        this->dh = lib->crypto->create_dh(lib->crypto, group);
        if (!this->dh)
        {
@@ -691,11 +697,51 @@ static status_t send_server_key_exchange(private_tls_server_t *this,
                this->alert->add(this->alert, TLS_FATAL, TLS_INTERNAL_ERROR);
                return NEED_MORE;
        }
-
-       writer->write_data16(writer, params->prime);
-       writer->write_data16(writer, params->generator);
+       switch (group)
+       {
+               case ECP_256_BIT:
+                       writer->write_uint8(writer, TLS_ECC_NAMED_CURVE);
+                       writer->write_uint16(writer, TLS_SECP256R1);
+                       break;
+               case ECP_384_BIT:
+                       writer->write_uint8(writer, TLS_ECC_NAMED_CURVE);
+                       writer->write_uint16(writer, TLS_SECP384R1);
+                       break;
+               case ECP_521_BIT:
+                       writer->write_uint8(writer, TLS_ECC_NAMED_CURVE);
+                       writer->write_uint16(writer, TLS_SECP521R1);
+                       break;
+               case ECP_192_BIT:
+                       writer->write_uint8(writer, TLS_ECC_NAMED_CURVE);
+                       writer->write_uint16(writer, TLS_SECP192R1);
+                       break;
+               case ECP_224_BIT:
+                       writer->write_uint8(writer, TLS_ECC_NAMED_CURVE);
+                       writer->write_uint16(writer, TLS_SECP224R1);
+                       break;
+               default:
+                       /* MODP groups */
+                       params = diffie_hellman_get_params(group);
+                       if (!params)
+                       {
+                               DBG1(DBG_TLS, "no parameters found for DH group %N",
+                                        diffie_hellman_group_names, group);
+                               this->alert->add(this->alert, TLS_FATAL, TLS_INTERNAL_ERROR);
+                               return NEED_MORE;
+                       }
+                       writer->write_data16(writer, params->prime);
+                       writer->write_data16(writer, params->generator);
+                       break;
+       }
        this->dh->get_my_public_value(this->dh, &chunk);
-       writer->write_data16(writer, chunk);
+       if (params)
+       {
+               writer->write_data16(writer, chunk);
+       }
+       else
+       {       /* 8bit header for EC groups */
+               writer->write_data8(writer, chunk);
+       }
        free(chunk.ptr);
 
        chunk = chunk_cat("ccc", chunk_from_thing(this->client_random),