int _gnutls_proc_ecdh_common_server_kx(gnutls_session_t session, uint8_t * data, size_t _data_size) { int i, ret, point_size; gnutls_ecc_curve_t curve; ssize_t data_size = _data_size; /* just in case we are resuming a session */ gnutls_pk_params_release(&session->key.ecdh_params); gnutls_pk_params_init(&session->key.ecdh_params); i = 0; DECR_LEN(data_size, 1); if (data[i++] != 3) return gnutls_assert_val(GNUTLS_E_ECC_NO_SUPPORTED_CURVES); DECR_LEN(data_size, 2); curve = _gnutls_tls_id_to_ecc_curve(_gnutls_read_uint16(&data[i])); i += 2; ret = _gnutls_session_supports_ecc_curve(session, curve); if (ret < 0) return gnutls_assert_val(ret); _gnutls_session_ecc_curve_set(session, curve); DECR_LEN(data_size, 1); point_size = data[i]; i++; DECR_LEN(data_size, point_size); ret = _gnutls_ecc_ansi_x963_import(&data[i], point_size, &session->key.ecdh_x, &session->key.ecdh_y); if (ret < 0) return gnutls_assert_val(ret); i += point_size; return i; }
/* * In case of a server: if a SUPPORTED_ECC extension type is received then it stores * into the session security parameters the new value. The server may use gnutls_session_certificate_type_get(), * to access it. * * In case of a client: If a supported_eccs have been specified then we send the extension. * */ static int _gnutls_supported_ecc_recv_params(gnutls_session_t session, const uint8_t * data, size_t _data_size) { int new_type = -1, ret, i; ssize_t data_size = _data_size; uint16_t len; const uint8_t *p = data; if (session->security_parameters.entity == GNUTLS_CLIENT) { /* A client shouldn't receive this extension, but of course * there are servers out there that send it. Just ignore it. */ _gnutls_debug_log("received SUPPORTED ECC extension on client side!!!\n"); return 0; } else { /* SERVER SIDE - we must check if the sent supported ecc type is the right one */ if (data_size < 2) return gnutls_assert_val (GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION); DECR_LEN(data_size, 2); len = _gnutls_read_uint16(p); p += 2; if (len % 2 != 0) return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH); DECR_LEN(data_size, len); for (i = 0; i < len; i += 2) { new_type = _gnutls_tls_id_to_ecc_curve(_gnutls_read_uint16 (&p[i])); if (new_type < 0) continue; /* Check if we support this supported_ecc */ if ((ret = _gnutls_session_supports_ecc_curve(session, new_type)) < 0) { continue; } else break; /* new_type is ok */ } if (new_type < 0) { gnutls_assert(); return GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER; } if ((ret = _gnutls_session_supports_ecc_curve(session, new_type)) < 0) { /* The peer has requested unsupported ecc * types. Instead of failing, procceed normally. * (the ciphersuite selection would fail, or a * non certificate ciphersuite will be selected). */ return gnutls_assert_val(0); } _gnutls_session_ecc_curve_set(session, new_type); } return 0; }