asterisk/main/sdp_srtp.c

138 lines
3.3 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2006 - 2007, Mikael Magnusson
*
* Mikael Magnusson <mikma@users.sourceforge.net>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
*
* \brief SRTP and SDP Security descriptions
*
* Specified in RFC 3711, 6188, 7714, and 4568
*
* \author Mikael Magnusson <mikma@users.sourceforge.net>
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/linkedlists.h" /* for AST_LIST_NEXT, etc */
#include "asterisk/logger.h" /* for ast_log, LOG_ERROR, etc */
#include "asterisk/sdp_srtp.h" /* for ast_sdp_srtp, etc */
/*! Registered SDP crypto API */
static struct ast_sdp_crypto_api *sdp_crypto_api;
struct ast_sdp_srtp *ast_sdp_srtp_alloc(void)
{
if (!ast_rtp_engine_srtp_is_registered()) {
ast_debug(1, "No SRTP module loaded, can't setup SRTP session.\n");
return NULL;
}
return ast_calloc(1, sizeof(struct ast_sdp_srtp));
}
void ast_sdp_srtp_destroy(struct ast_sdp_srtp *srtp)
{
struct ast_sdp_srtp *next;
for (next = AST_LIST_NEXT(srtp, sdp_srtp_list);
srtp;
srtp = next, next = srtp ? AST_LIST_NEXT(srtp, sdp_srtp_list) : NULL) {
ast_sdp_crypto_destroy(srtp->crypto);
srtp->crypto = NULL;
ast_free(srtp);
}
}
void ast_sdp_crypto_destroy(struct ast_sdp_crypto *crypto)
{
if (sdp_crypto_api) {
sdp_crypto_api->dtor(crypto);
}
}
struct ast_sdp_crypto *ast_sdp_crypto_alloc(void)
{
if (!sdp_crypto_api) {
return NULL;
}
return sdp_crypto_api->alloc();
}
int ast_sdp_crypto_process(struct ast_rtp_instance *rtp, struct ast_sdp_srtp *srtp, const char *attr)
{
if (!sdp_crypto_api) {
return -1;
}
return sdp_crypto_api->parse_offer(rtp, srtp, attr);
}
int ast_sdp_crypto_build_offer(struct ast_sdp_crypto *p, int taglen)
{
if (!sdp_crypto_api) {
return -1;
}
return sdp_crypto_api->build_offer(p, taglen);
}
const char *ast_sdp_srtp_get_attrib(struct ast_sdp_srtp *srtp, int dtls_enabled, int default_taglen_32)
{
if (!sdp_crypto_api) {
return NULL;
}
return sdp_crypto_api->get_attr(srtp, dtls_enabled, default_taglen_32);
}
char *ast_sdp_get_rtp_profile(unsigned int sdes_active, struct ast_rtp_instance *instance, unsigned int using_avpf,
unsigned int force_avp)
{
struct ast_rtp_engine_dtls *dtls;
if ((dtls = ast_rtp_instance_get_dtls(instance)) && dtls->active(instance)) {
if (force_avp) {
return using_avpf ? "RTP/SAVPF" : "RTP/SAVP";
} else {
return using_avpf ? "UDP/TLS/RTP/SAVPF" : "UDP/TLS/RTP/SAVP";
}
} else {
if (using_avpf) {
return sdes_active ? "RTP/SAVPF" : "RTP/AVPF";
} else {
return sdes_active ? "RTP/SAVP" : "RTP/AVP";
}
}
}
int ast_sdp_crypto_register(struct ast_sdp_crypto_api *api)
{
if (sdp_crypto_api) {
return -1;
}
sdp_crypto_api = api;
return 0;
}
void ast_sdp_crypto_unregister(struct ast_sdp_crypto_api *api)
{
if (sdp_crypto_api == api) {
sdp_crypto_api = NULL;
}
}