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-rw-r--r--lib/ext/alpn.c327
1 files changed, 327 insertions, 0 deletions
diff --git a/lib/ext/alpn.c b/lib/ext/alpn.c
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+++ b/lib/ext/alpn.c
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+/*
+ * Copyright (C) 2013 Nikos Mavrogiannopoulos
+ * Copyright (C) 2017 Red Hat, Inc.
+ *
+ * This file is part of GnuTLS.
+ *
+ * The GnuTLS is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>
+ *
+ */
+
+#include "gnutls_int.h"
+#include "auth.h"
+#include "errors.h"
+#include "num.h"
+#include <ext/alpn.h>
+
+static int _gnutls_alpn_recv_params(gnutls_session_t session,
+ const uint8_t * data,
+ size_t data_size);
+static int _gnutls_alpn_send_params(gnutls_session_t session,
+ gnutls_buffer_st * extdata);
+
+static void _gnutls_alpn_deinit_data(gnutls_ext_priv_data_t priv);
+
+
+const hello_ext_entry_st ext_mod_alpn = {
+ .name = "ALPN",
+ .tls_id = 16,
+ .gid = GNUTLS_EXTENSION_ALPN,
+ /* this extension must be parsed even on resumption */
+ .client_parse_point = GNUTLS_EXT_MANDATORY,
+ .server_parse_point = GNUTLS_EXT_MANDATORY,
+ .validity = GNUTLS_EXT_FLAG_TLS | GNUTLS_EXT_FLAG_DTLS |
+ GNUTLS_EXT_FLAG_CLIENT_HELLO | GNUTLS_EXT_FLAG_EE |
+ GNUTLS_EXT_FLAG_TLS12_SERVER_HELLO,
+ .recv_func = _gnutls_alpn_recv_params,
+ .send_func = _gnutls_alpn_send_params,
+ .deinit_func = _gnutls_alpn_deinit_data,
+ .cannot_be_overriden = 1
+};
+
+static int
+_gnutls_alpn_recv_params(gnutls_session_t session,
+ const uint8_t * data, size_t data_size)
+{
+ unsigned int i;
+ int ret;
+ const uint8_t *p = data;
+ unsigned len1, len;
+ alpn_ext_st *priv;
+ gnutls_ext_priv_data_t epriv;
+ int selected_protocol_index;
+
+ ret =
+ _gnutls_hello_ext_get_priv(session, GNUTLS_EXTENSION_ALPN,
+ &epriv);
+ if (ret < 0)
+ return 0;
+
+ priv = epriv;
+
+ DECR_LENGTH_RET(data_size, 2, GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+ len = _gnutls_read_uint16(p);
+ p += 2;
+
+ if (len == 0 || len > (size_t)data_size)
+ return
+ gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+
+ if (session->security_parameters.entity == GNUTLS_SERVER) {
+ selected_protocol_index = MAX_ALPN_PROTOCOLS+1;
+
+ while (data_size > 0) {
+ DECR_LENGTH_RET(data_size, 1, GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+ len1 = *p;
+ p += 1;
+ DECR_LENGTH_RET(data_size, len1, GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+
+ if (len1 == 0)
+ return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+
+ for (i = 0; i < priv->size; i++) {
+ if (priv->protocol_size[i] == len1
+ && memcmp(p, priv->protocols[i],
+ len1) == 0) {
+
+ if (priv->flags & GNUTLS_ALPN_SERVER_PRECEDENCE) {
+ if (selected_protocol_index > (int)i) {
+ selected_protocol_index = i;
+ priv->selected_protocol =
+ priv->protocols[i];
+ priv->selected_protocol_size =
+ priv->protocol_size[i];
+ break;
+ }
+ } else {
+ priv->selected_protocol =
+ priv->protocols[i];
+ priv->selected_protocol_size =
+ priv->protocol_size[i];
+ return 0;
+ }
+ }
+ }
+ p += len1;
+ }
+ } else {
+ DECR_LENGTH_RET(data_size, 1, GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+ len1 = *p;
+ p += 1;
+ DECR_LENGTH_RET(data_size, len1, GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
+
+ for (i = 0; i < priv->size; i++) {
+ if (priv->protocol_size[i] == len1
+ && memcmp(p, priv->protocols[i], len1) == 0) {
+ priv->selected_protocol =
+ priv->protocols[i];
+ priv->selected_protocol_size =
+ priv->protocol_size[i];
+ break;
+ }
+ }
+ /*p += len1;*/
+ }
+
+ if (priv->selected_protocol == NULL
+ && (priv->flags & GNUTLS_ALPN_MAND))
+ return gnutls_assert_val(GNUTLS_E_NO_APPLICATION_PROTOCOL);
+
+ return 0;
+}
+
+static int
+_gnutls_alpn_send_params(gnutls_session_t session,
+ gnutls_buffer_st * extdata)
+{
+ unsigned i;
+ int total_size = 0, ret;
+ alpn_ext_st *priv;
+ gnutls_ext_priv_data_t epriv;
+
+ ret =
+ _gnutls_hello_ext_get_priv(session, GNUTLS_EXTENSION_ALPN,
+ &epriv);
+ if (ret < 0)
+ return 0;
+
+ priv = epriv;
+
+ if (priv->size == 0)
+ return 0;
+
+ if (session->security_parameters.entity == GNUTLS_SERVER) {
+ if (priv->selected_protocol_size == 0)
+ return 0;
+
+ ret =
+ _gnutls_buffer_append_prefix(extdata, 16,
+ priv->
+ selected_protocol_size +
+ 1);
+ if (ret < 0)
+ return gnutls_assert_val(ret);
+
+ total_size += 2;
+
+ ret =
+ _gnutls_buffer_append_data_prefix(extdata, 8,
+ priv->
+ selected_protocol,
+ priv->
+ selected_protocol_size);
+ if (ret < 0)
+ return gnutls_assert_val(ret);
+
+ total_size += 1 + priv->selected_protocol_size;
+ } else {
+ int t = 0;
+ for (i = 0; i < priv->size; i++)
+ t += priv->protocol_size[i] + 1;
+
+ ret = _gnutls_buffer_append_prefix(extdata, 16, t);
+ if (ret < 0)
+ return gnutls_assert_val(ret);
+
+ total_size += 2;
+
+ for (i = 0; i < priv->size; i++) {
+ ret =
+ _gnutls_buffer_append_data_prefix(extdata, 8,
+ priv->
+ protocols[i],
+ priv->
+ protocol_size
+ [i]);
+ if (ret < 0)
+ return gnutls_assert_val(ret);
+
+ total_size += 1 + priv->protocol_size[i];
+ }
+ }
+
+ return total_size;
+}
+
+/**
+ * gnutls_alpn_get_selected_protocol:
+ * @session: is a #gnutls_session_t type.
+ * @protocol: will hold the protocol name
+ *
+ * This function allows you to get the negotiated protocol name. The
+ * returned protocol should be treated as opaque, constant value and
+ * only valid during the session life.
+ *
+ * The selected protocol is the first supported by the list sent
+ * by the client.
+ *
+ * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned,
+ * otherwise a negative error code is returned.
+ *
+ * Since 3.2.0
+ **/
+int
+gnutls_alpn_get_selected_protocol(gnutls_session_t session,
+ gnutls_datum_t * protocol)
+{
+ alpn_ext_st *priv;
+ int ret;
+ gnutls_ext_priv_data_t epriv;
+
+ ret =
+ _gnutls_hello_ext_get_priv(session, GNUTLS_EXTENSION_ALPN,
+ &epriv);
+ if (ret < 0) {
+ gnutls_assert();
+ return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
+ }
+
+ priv = epriv;
+
+ if (priv->selected_protocol_size == 0)
+ return
+ gnutls_assert_val
+ (GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE);
+
+ protocol->data = priv->selected_protocol;
+ protocol->size = priv->selected_protocol_size;
+
+ return 0;
+}
+
+/**
+ * gnutls_alpn_set_protocols:
+ * @session: is a #gnutls_session_t type.
+ * @protocols: is the protocol names to add.
+ * @protocols_size: the number of protocols to add.
+ * @flags: zero or a sequence of %gnutls_alpn_flags_t
+ *
+ * This function is to be used by both clients and servers, to declare
+ * the supported ALPN protocols, which are used during negotiation with peer.
+ *
+ * See %gnutls_alpn_flags_t description for the documentation of available
+ * flags.
+ *
+ * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned,
+ * otherwise a negative error code is returned.
+ *
+ * Since 3.2.0
+ **/
+int
+gnutls_alpn_set_protocols(gnutls_session_t session,
+ const gnutls_datum_t * protocols,
+ unsigned protocols_size, unsigned int flags)
+{
+ int ret;
+ alpn_ext_st *priv;
+ gnutls_ext_priv_data_t epriv;
+ unsigned i;
+
+ ret =
+ _gnutls_hello_ext_get_priv(session, GNUTLS_EXTENSION_ALPN,
+ &epriv);
+ if (ret < 0) {
+ priv = gnutls_calloc(1, sizeof(*priv));
+ if (priv == NULL) {
+ gnutls_assert();
+ return GNUTLS_E_MEMORY_ERROR;
+ }
+ epriv = priv;
+ _gnutls_hello_ext_set_priv(session,
+ GNUTLS_EXTENSION_ALPN, epriv);
+ } else
+ priv = epriv;
+
+ if (protocols_size > MAX_ALPN_PROTOCOLS)
+ return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
+
+ for (i = 0; i < protocols_size; i++) {
+ if (protocols[i].size >= MAX_ALPN_PROTOCOL_NAME)
+ return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
+
+ memcpy(priv->protocols[i], protocols[i].data,
+ protocols[i].size);
+ priv->protocol_size[i] = protocols[i].size;
+ priv->size++;
+ }
+ priv->flags = flags;
+
+ return 0;
+}
+
+
+static void _gnutls_alpn_deinit_data(gnutls_ext_priv_data_t priv)
+{
+ gnutls_free(priv);
+}