gstreamer/ext/webrtc/webrtcsdp.c

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/* GStreamer
* Copyright (C) 2017 Matthew Waters <matthew@centricular.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "webrtcsdp.h"
#include "utils.h"
#include <string.h>
#include <stdlib.h>
#define IS_EMPTY_SDP_ATTRIBUTE(val) (val == NULL || g_strcmp0(val, "") == 0)
const gchar *
_sdp_source_to_string (SDPSource source)
{
switch (source) {
case SDP_LOCAL:
return "local";
case SDP_REMOTE:
return "remote";
default:
return "none";
}
}
static gboolean
_check_valid_state_for_sdp_change (GstWebRTCSignalingState state,
SDPSource source, GstWebRTCSDPType type, GError ** error)
{
#define STATE(val) GST_WEBRTC_SIGNALING_STATE_ ## val
#define TYPE(val) GST_WEBRTC_SDP_TYPE_ ## val
if (source == SDP_LOCAL && type == TYPE (OFFER) && state == STATE (STABLE))
return TRUE;
if (source == SDP_LOCAL && type == TYPE (OFFER)
&& state == STATE (HAVE_LOCAL_OFFER))
return TRUE;
if (source == SDP_LOCAL && type == TYPE (ANSWER)
&& state == STATE (HAVE_REMOTE_OFFER))
return TRUE;
if (source == SDP_LOCAL && type == TYPE (PRANSWER)
&& state == STATE (HAVE_REMOTE_OFFER))
return TRUE;
if (source == SDP_LOCAL && type == TYPE (PRANSWER)
&& state == STATE (HAVE_LOCAL_PRANSWER))
return TRUE;
if (source == SDP_REMOTE && type == TYPE (OFFER) && state == STATE (STABLE))
return TRUE;
if (source == SDP_REMOTE && type == TYPE (OFFER)
&& state == STATE (HAVE_REMOTE_OFFER))
return TRUE;
if (source == SDP_REMOTE && type == TYPE (ANSWER)
&& state == STATE (HAVE_LOCAL_OFFER))
return TRUE;
if (source == SDP_REMOTE && type == TYPE (PRANSWER)
&& state == STATE (HAVE_LOCAL_OFFER))
return TRUE;
if (source == SDP_REMOTE && type == TYPE (PRANSWER)
&& state == STATE (HAVE_REMOTE_PRANSWER))
return TRUE;
{
gchar *state_str = _enum_value_to_string (GST_TYPE_WEBRTC_SIGNALING_STATE,
state);
gchar *type_str = _enum_value_to_string (GST_TYPE_WEBRTC_SDP_TYPE, type);
g_set_error (error, GST_WEBRTC_BIN_ERROR,
GST_WEBRTC_BIN_ERROR_INVALID_STATE,
"Not in the correct state (%s) for setting %s %s description",
state_str, _sdp_source_to_string (source), type_str);
g_free (state_str);
g_free (type_str);
}
return FALSE;
#undef STATE
#undef TYPE
}
static gboolean
_check_sdp_crypto (SDPSource source, GstWebRTCSessionDescription * sdp,
GError ** error)
{
const gchar *message_fingerprint, *fingerprint;
const GstSDPKey *key;
int i;
key = gst_sdp_message_get_key (sdp->sdp);
if (!IS_EMPTY_SDP_ATTRIBUTE (key->data)) {
g_set_error_literal (error, GST_WEBRTC_BIN_ERROR,
GST_WEBRTC_BIN_ERROR_BAD_SDP, "sdp contains a k line");
return FALSE;
}
message_fingerprint = fingerprint =
gst_sdp_message_get_attribute_val (sdp->sdp, "fingerprint");
for (i = 0; i < gst_sdp_message_medias_len (sdp->sdp); i++) {
const GstSDPMedia *media = gst_sdp_message_get_media (sdp->sdp, i);
const gchar *media_fingerprint =
gst_sdp_media_get_attribute_val (media, "fingerprint");
if (!IS_EMPTY_SDP_ATTRIBUTE (message_fingerprint)
&& !IS_EMPTY_SDP_ATTRIBUTE (media_fingerprint)) {
g_set_error (error, GST_WEBRTC_BIN_ERROR,
GST_WEBRTC_BIN_ERROR_FINGERPRINT,
"No fingerprint lines in sdp for media %u", i);
return FALSE;
}
if (IS_EMPTY_SDP_ATTRIBUTE (fingerprint)) {
fingerprint = media_fingerprint;
}
if (!IS_EMPTY_SDP_ATTRIBUTE (media_fingerprint)
&& g_strcmp0 (fingerprint, media_fingerprint) != 0) {
g_set_error (error, GST_WEBRTC_BIN_ERROR,
GST_WEBRTC_BIN_ERROR_FINGERPRINT,
"Fingerprint in media %u differs from %s fingerprint. "
"\'%s\' != \'%s\'", i, message_fingerprint ? "global" : "previous",
fingerprint, media_fingerprint);
return FALSE;
}
}
return TRUE;
}
#if 0
static gboolean
_session_has_attribute_key (const GstSDPMessage * msg, const gchar * key)
{
int i;
for (i = 0; i < gst_sdp_message_attributes_len (msg); i++) {
const GstSDPAttribute *attr = gst_sdp_message_get_attribute (msg, i);
if (g_strcmp0 (attr->key, key) == 0)
return TRUE;
}
return FALSE;
}
static gboolean
_session_has_attribute_key_value (const GstSDPMessage * msg, const gchar * key,
const gchar * value)
{
int i;
for (i = 0; i < gst_sdp_message_attributes_len (msg); i++) {
const GstSDPAttribute *attr = gst_sdp_message_get_attribute (msg, i);
if (g_strcmp0 (attr->key, key) == 0 && g_strcmp0 (attr->value, value) == 0)
return TRUE;
}
return FALSE;
}
static gboolean
_check_trickle_ice (GstSDPMessage * msg, GError ** error)
{
if (!_session_has_attribute_key_value (msg, "ice-options", "trickle")) {
g_set_error_literal (error, GST_WEBRTC_BIN_ERROR,
GST_WEBRTC_BIN_ERROR_BAD_SDP,
"No required \'a=ice-options:trickle\' line in sdp");
}
return TRUE;
}
#endif
gboolean
_media_has_attribute_key (const GstSDPMedia * media, const gchar * key)
{
int i;
for (i = 0; i < gst_sdp_media_attributes_len (media); i++) {
const GstSDPAttribute *attr = gst_sdp_media_get_attribute (media, i);
if (g_strcmp0 (attr->key, key) == 0)
return TRUE;
}
return FALSE;
}
static gboolean
_media_has_mid (const GstSDPMedia * media, guint media_idx, GError ** error)
{
const gchar *mid = gst_sdp_media_get_attribute_val (media, "mid");
if (IS_EMPTY_SDP_ATTRIBUTE (mid)) {
g_set_error (error, GST_WEBRTC_BIN_ERROR, GST_WEBRTC_BIN_ERROR_BAD_SDP,
"media %u is missing or contains an empty \'mid\' attribute",
media_idx);
return FALSE;
}
return TRUE;
}
const gchar *
_media_get_ice_ufrag (const GstSDPMessage * msg, guint media_idx)
{
const gchar *ice_ufrag;
ice_ufrag = gst_sdp_message_get_attribute_val (msg, "ice-ufrag");
if (IS_EMPTY_SDP_ATTRIBUTE (ice_ufrag)) {
const GstSDPMedia *media = gst_sdp_message_get_media (msg, media_idx);
ice_ufrag = gst_sdp_media_get_attribute_val (media, "ice-ufrag");
if (IS_EMPTY_SDP_ATTRIBUTE (ice_ufrag))
return NULL;
}
return ice_ufrag;
}
const gchar *
_media_get_ice_pwd (const GstSDPMessage * msg, guint media_idx)
{
const gchar *ice_pwd;
ice_pwd = gst_sdp_message_get_attribute_val (msg, "ice-pwd");
if (IS_EMPTY_SDP_ATTRIBUTE (ice_pwd)) {
const GstSDPMedia *media = gst_sdp_message_get_media (msg, media_idx);
ice_pwd = gst_sdp_media_get_attribute_val (media, "ice-pwd");
if (IS_EMPTY_SDP_ATTRIBUTE (ice_pwd))
return NULL;
}
return ice_pwd;
}
static gboolean
_media_has_setup (const GstSDPMedia * media, guint media_idx, GError ** error)
{
static const gchar *valid_setups[] = { "actpass", "active", "passive", NULL };
const gchar *setup = gst_sdp_media_get_attribute_val (media, "setup");
if (IS_EMPTY_SDP_ATTRIBUTE (setup)) {
g_set_error (error, GST_WEBRTC_BIN_ERROR, GST_WEBRTC_BIN_ERROR_BAD_SDP,
"media %u is missing or contains an empty \'setup\' attribute",
media_idx);
return FALSE;
}
if (!g_strv_contains (valid_setups, setup)) {
g_set_error (error, GST_WEBRTC_BIN_ERROR, GST_WEBRTC_BIN_ERROR_BAD_SDP,
"media %u contains unknown \'setup\' attribute, \'%s\'", media_idx,
setup);
return FALSE;
}
return TRUE;
}
#if 0
static gboolean
_media_has_dtls_id (const GstSDPMedia * media, guint media_idx, GError ** error)
{
const gchar *dtls_id = gst_sdp_media_get_attribute_val (media, "ice-pwd");
if (IS_EMPTY_SDP_ATTRIBUTE (dtls_id)) {
g_set_error (error, GST_WEBRTC_BIN_ERROR, GST_WEBRTC_BIN_ERROR_BAD_SDP,
"media %u is missing or contains an empty \'dtls-id\' attribute",
media_idx);
return FALSE;
}
return TRUE;
}
#endif
gboolean
validate_sdp (GstWebRTCSignalingState state, SDPSource source,
GstWebRTCSessionDescription * sdp, GError ** error)
{
const gchar *group, *bundle_ice_ufrag = NULL, *bundle_ice_pwd = NULL;
gchar **group_members = NULL;
gboolean is_bundle = FALSE;
int i;
if (!_check_valid_state_for_sdp_change (state, source, sdp->type, error))
return FALSE;
if (!_check_sdp_crypto (source, sdp, error))
return FALSE;
/* not explicitly required
if (ICE && !_check_trickle_ice (sdp->sdp))
return FALSE;*/
group = gst_sdp_message_get_attribute_val (sdp->sdp, "group");
is_bundle = group && g_str_has_prefix (group, "BUNDLE");
if (is_bundle)
group_members = g_strsplit (&group[6], " ", -1);
for (i = 0; i < gst_sdp_message_medias_len (sdp->sdp); i++) {
const GstSDPMedia *media = gst_sdp_message_get_media (sdp->sdp, i);
const gchar *mid;
gboolean media_in_bundle = FALSE;
if (!_media_has_mid (media, i, error))
goto fail;
mid = gst_sdp_media_get_attribute_val (media, "mid");
media_in_bundle = is_bundle
&& g_strv_contains ((const gchar **) group_members, mid);
if (!_media_get_ice_ufrag (sdp->sdp, i)) {
g_set_error (error, GST_WEBRTC_BIN_ERROR, GST_WEBRTC_BIN_ERROR_BAD_SDP,
"media %u is missing or contains an empty \'ice-ufrag\' attribute",
i);
goto fail;
}
if (!_media_get_ice_pwd (sdp->sdp, i)) {
g_set_error (error, GST_WEBRTC_BIN_ERROR, GST_WEBRTC_BIN_ERROR_BAD_SDP,
"media %u is missing or contains an empty \'ice-pwd\' attribute", i);
goto fail;
}
if (!_media_has_setup (media, i, error))
goto fail;
2019-09-02 19:08:44 +00:00
/* check parameters in bundle are the same */
if (media_in_bundle) {
const gchar *ice_ufrag =
gst_sdp_media_get_attribute_val (media, "ice-ufrag");
const gchar *ice_pwd = gst_sdp_media_get_attribute_val (media, "ice-pwd");
if (!bundle_ice_ufrag)
bundle_ice_ufrag = ice_ufrag;
else if (g_strcmp0 (bundle_ice_ufrag, ice_ufrag) != 0) {
g_set_error (error, GST_WEBRTC_BIN_ERROR, GST_WEBRTC_BIN_ERROR_BAD_SDP,
"media %u has different ice-ufrag values in bundle. "
"%s != %s", i, bundle_ice_ufrag, ice_ufrag);
goto fail;
}
if (!bundle_ice_pwd) {
bundle_ice_pwd = ice_pwd;
} else if (g_strcmp0 (bundle_ice_pwd, ice_pwd) != 0) {
g_set_error (error, GST_WEBRTC_BIN_ERROR, GST_WEBRTC_BIN_ERROR_BAD_SDP,
"media %u has different ice-pwd values in bundle. "
"%s != %s", i, bundle_ice_pwd, ice_pwd);
goto fail;
}
}
}
g_strfreev (group_members);
return TRUE;
fail:
g_strfreev (group_members);
return FALSE;
}
GstWebRTCRTPTransceiverDirection
_get_direction_from_media (const GstSDPMedia * media)
{
GstWebRTCRTPTransceiverDirection new_dir =
GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE;
int i;
for (i = 0; i < gst_sdp_media_attributes_len (media); i++) {
const GstSDPAttribute *attr = gst_sdp_media_get_attribute (media, i);
if (g_strcmp0 (attr->key, "sendonly") == 0) {
if (new_dir != GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE) {
GST_ERROR ("Multiple direction attributes");
return GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE;
}
new_dir = GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_SENDONLY;
} else if (g_strcmp0 (attr->key, "sendrecv") == 0) {
if (new_dir != GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE) {
GST_ERROR ("Multiple direction attributes");
return GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE;
}
new_dir = GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_SENDRECV;
} else if (g_strcmp0 (attr->key, "recvonly") == 0) {
if (new_dir != GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE) {
GST_ERROR ("Multiple direction attributes");
return GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE;
}
new_dir = GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_RECVONLY;
} else if (g_strcmp0 (attr->key, "inactive") == 0) {
if (new_dir != GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE) {
GST_ERROR ("Multiple direction attributes");
return GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE;
}
new_dir = GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_INACTIVE;
}
}
return new_dir;
}
#define DIR(val) GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_ ## val
GstWebRTCRTPTransceiverDirection
_intersect_answer_directions (GstWebRTCRTPTransceiverDirection offer,
GstWebRTCRTPTransceiverDirection answer)
{
if (offer == DIR (INACTIVE) || answer == DIR (INACTIVE))
return DIR (INACTIVE);
if (offer == DIR (SENDONLY) && answer == DIR (SENDRECV))
return DIR (RECVONLY);
if (offer == DIR (SENDONLY) && answer == DIR (RECVONLY))
return DIR (RECVONLY);
if (offer == DIR (RECVONLY) && answer == DIR (SENDRECV))
return DIR (SENDONLY);
if (offer == DIR (RECVONLY) && answer == DIR (SENDONLY))
return DIR (SENDONLY);
if (offer == DIR (SENDRECV) && answer == DIR (SENDRECV))
return DIR (SENDRECV);
if (offer == DIR (SENDRECV) && answer == DIR (SENDONLY))
return DIR (SENDONLY);
if (offer == DIR (SENDRECV) && answer == DIR (RECVONLY))
return DIR (RECVONLY);
if (offer == DIR (RECVONLY) && answer == DIR (RECVONLY))
return DIR (INACTIVE);
if (offer == DIR (SENDONLY) && answer == DIR (SENDONLY))
return DIR (INACTIVE);
return DIR (NONE);
}
void
_media_replace_direction (GstSDPMedia * media,
GstWebRTCRTPTransceiverDirection direction)
{
gchar *dir_str;
int i;
dir_str =
_enum_value_to_string (GST_TYPE_WEBRTC_RTP_TRANSCEIVER_DIRECTION,
direction);
for (i = 0; i < gst_sdp_media_attributes_len (media); i++) {
const GstSDPAttribute *attr = gst_sdp_media_get_attribute (media, i);
if (g_strcmp0 (attr->key, "sendonly") == 0
|| g_strcmp0 (attr->key, "sendrecv") == 0
|| g_strcmp0 (attr->key, "recvonly") == 0
|| g_strcmp0 (attr->key, "inactive") == 0) {
GstSDPAttribute new_attr = { 0, };
GST_TRACE ("replace %s with %s", attr->key, dir_str);
gst_sdp_attribute_set (&new_attr, dir_str, "");
gst_sdp_media_replace_attribute (media, i, &new_attr);
g_free (dir_str);
return;
}
}
GST_TRACE ("add %s", dir_str);
gst_sdp_media_add_attribute (media, dir_str, "");
g_free (dir_str);
}
GstWebRTCRTPTransceiverDirection
_get_final_direction (GstWebRTCRTPTransceiverDirection local_dir,
GstWebRTCRTPTransceiverDirection remote_dir)
{
GstWebRTCRTPTransceiverDirection new_dir;
new_dir = DIR (NONE);
switch (local_dir) {
case DIR (INACTIVE):
new_dir = DIR (INACTIVE);
break;
case DIR (SENDONLY):
if (remote_dir == DIR (SENDONLY)) {
GST_ERROR ("remote SDP has the same directionality. "
"This is not legal.");
return DIR (NONE);
} else if (remote_dir == DIR (INACTIVE)) {
new_dir = DIR (INACTIVE);
} else {
new_dir = DIR (SENDONLY);
}
break;
case DIR (RECVONLY):
if (remote_dir == DIR (RECVONLY)) {
GST_ERROR ("remote SDP has the same directionality. "
"This is not legal.");
return DIR (NONE);
} else if (remote_dir == DIR (INACTIVE)) {
new_dir = DIR (INACTIVE);
} else {
new_dir = DIR (RECVONLY);
}
break;
case DIR (SENDRECV):
if (remote_dir == DIR (INACTIVE)) {
new_dir = DIR (INACTIVE);
} else if (remote_dir == DIR (SENDONLY)) {
new_dir = DIR (RECVONLY);
} else if (remote_dir == DIR (RECVONLY)) {
new_dir = DIR (SENDONLY);
} else if (remote_dir == DIR (SENDRECV)) {
new_dir = DIR (SENDRECV);
}
break;
default:
g_assert_not_reached ();
break;
}
if (new_dir == DIR (NONE)) {
GST_ERROR ("Abnormal situation!");
return DIR (NONE);
}
return new_dir;
}
#undef DIR
#define SETUP(val) GST_WEBRTC_DTLS_SETUP_ ## val
GstWebRTCDTLSSetup
_get_dtls_setup_from_media (const GstSDPMedia * media)
{
int i;
for (i = 0; i < gst_sdp_media_attributes_len (media); i++) {
const GstSDPAttribute *attr = gst_sdp_media_get_attribute (media, i);
if (g_strcmp0 (attr->key, "setup") == 0) {
if (g_strcmp0 (attr->value, "actpass") == 0) {
return SETUP (ACTPASS);
} else if (g_strcmp0 (attr->value, "active") == 0) {
return SETUP (ACTIVE);
} else if (g_strcmp0 (attr->value, "passive") == 0) {
return SETUP (PASSIVE);
} else {
GST_ERROR ("unknown setup value %s", attr->value);
return SETUP (NONE);
}
}
}
GST_LOG ("no setup attribute in media");
return SETUP (NONE);
}
GstWebRTCDTLSSetup
_intersect_dtls_setup (GstWebRTCDTLSSetup offer)
{
switch (offer) {
case SETUP (NONE): /* default is active */
case SETUP (ACTPASS):
case SETUP (PASSIVE):
return SETUP (ACTIVE);
case SETUP (ACTIVE):
return SETUP (PASSIVE);
default:
return SETUP (NONE);
}
}
void
_media_replace_setup (GstSDPMedia * media, GstWebRTCDTLSSetup setup)
{
gchar *setup_str;
int i;
setup_str = _enum_value_to_string (GST_TYPE_WEBRTC_DTLS_SETUP, setup);
for (i = 0; i < gst_sdp_media_attributes_len (media); i++) {
const GstSDPAttribute *attr = gst_sdp_media_get_attribute (media, i);
if (g_strcmp0 (attr->key, "setup") == 0) {
GstSDPAttribute new_attr = { 0, };
GST_TRACE ("replace setup:%s with setup:%s", attr->value, setup_str);
gst_sdp_attribute_set (&new_attr, "setup", setup_str);
gst_sdp_media_replace_attribute (media, i, &new_attr);
return;
}
}
GST_TRACE ("add setup:%s", setup_str);
gst_sdp_media_add_attribute (media, "setup", setup_str);
g_free (setup_str);
}
GstWebRTCDTLSSetup
_get_final_setup (GstWebRTCDTLSSetup local_setup,
GstWebRTCDTLSSetup remote_setup)
{
GstWebRTCDTLSSetup new_setup;
new_setup = SETUP (NONE);
switch (local_setup) {
case SETUP (NONE):
/* someone's done a bad job of mangling the SDP. or bugs */
g_critical ("Received a locally generated sdp without a parseable "
"\'a=setup\' line. This indicates a bug somewhere. Bailing");
return SETUP (NONE);
case SETUP (ACTIVE):
if (remote_setup == SETUP (ACTIVE)) {
GST_ERROR ("remote SDP has the same "
"\'a=setup:active\' attribute. This is not legal");
return SETUP (NONE);
}
new_setup = SETUP (ACTIVE);
break;
case SETUP (PASSIVE):
if (remote_setup == SETUP (PASSIVE)) {
GST_ERROR ("remote SDP has the same "
"\'a=setup:passive\' attribute. This is not legal");
return SETUP (NONE);
}
new_setup = SETUP (PASSIVE);
break;
case SETUP (ACTPASS):
if (remote_setup == SETUP (ACTPASS)) {
GST_ERROR ("remote SDP has the same "
"\'a=setup:actpass\' attribute. This is not legal");
return SETUP (NONE);
}
if (remote_setup == SETUP (ACTIVE))
new_setup = SETUP (PASSIVE);
else if (remote_setup == SETUP (PASSIVE))
new_setup = SETUP (ACTIVE);
else if (remote_setup == SETUP (NONE)) {
/* XXX: what to do here? */
GST_WARNING ("unspecified situation. local: "
"\'a=setup:actpass\' remote: none/unparseable");
new_setup = SETUP (ACTIVE);
}
break;
default:
g_assert_not_reached ();
return SETUP (NONE);
}
if (new_setup == SETUP (NONE)) {
GST_ERROR ("Abnormal situation!");
return SETUP (NONE);
}
return new_setup;
}
#undef SETUP
gchar *
_generate_fingerprint_from_certificate (gchar * certificate,
GChecksumType checksum_type)
{
gchar **lines, *line;
guchar *tmp, *decoded, *digest;
GChecksum *checksum;
GString *fingerprint;
gsize decoded_length, digest_size;
gint state = 0;
guint save = 0;
int i;
g_return_val_if_fail (certificate != NULL, NULL);
/* 1. decode the certificate removing newlines and the certificate header
* and footer */
decoded = tmp = g_new0 (guchar, (strlen (certificate) / 4) * 3 + 3);
lines = g_strsplit (certificate, "\n", 0);
for (i = 0, line = lines[i]; line; line = lines[++i]) {
if (line[0] && !g_str_has_prefix (line, "-----"))
tmp += g_base64_decode_step (line, strlen (line), tmp, &state, &save);
}
g_strfreev (lines);
decoded_length = tmp - decoded;
/* 2. compute a checksum of the decoded certificate */
checksum = g_checksum_new (checksum_type);
digest_size = g_checksum_type_get_length (checksum_type);
digest = g_new (guint8, digest_size);
g_checksum_update (checksum, decoded, decoded_length);
g_checksum_get_digest (checksum, digest, &digest_size);
g_free (decoded);
/* 3. hex encode the checksum separated with ':'s */
fingerprint = g_string_new (NULL);
for (i = 0; i < digest_size; i++) {
if (i)
g_string_append (fingerprint, ":");
g_string_append_printf (fingerprint, "%02X", digest[i]);
}
g_free (digest);
g_checksum_free (checksum);
return g_string_free (fingerprint, FALSE);
}
#define DEFAULT_ICE_UFRAG_LEN 32
#define DEFAULT_ICE_PASSWORD_LEN 32
static const gchar *ice_credential_chars =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz" "0123456789" "+/";
void
_generate_ice_credentials (gchar ** ufrag, gchar ** password)
{
int i;
*ufrag = g_malloc0 (DEFAULT_ICE_UFRAG_LEN + 1);
for (i = 0; i < DEFAULT_ICE_UFRAG_LEN; i++)
(*ufrag)[i] =
ice_credential_chars[g_random_int_range (0,
strlen (ice_credential_chars))];
*password = g_malloc0 (DEFAULT_ICE_PASSWORD_LEN + 1);
for (i = 0; i < DEFAULT_ICE_PASSWORD_LEN; i++)
(*password)[i] =
ice_credential_chars[g_random_int_range (0,
strlen (ice_credential_chars))];
}
int
_get_sctp_port_from_media (const GstSDPMedia * media)
{
int i;
const gchar *format;
gchar *endptr;
if (gst_sdp_media_formats_len (media) != 1) {
/* only exactly one format is supported */
return -1;
}
format = gst_sdp_media_get_format (media, 0);
if (g_strcmp0 (format, "webrtc-datachannel") == 0) {
/* draft-ietf-mmusic-sctp-sdp-21, e.g. Firefox 63 and later */
for (i = 0; i < gst_sdp_media_attributes_len (media); i++) {
const GstSDPAttribute *attr = gst_sdp_media_get_attribute (media, i);
if (g_strcmp0 (attr->key, "sctp-port") == 0) {
gint64 port = g_ascii_strtoll (attr->value, &endptr, 10);
if (endptr == attr->value) {
/* conversion error */
return -1;
}
return port;
}
}
} else {
/* draft-ietf-mmusic-sctp-sdp-05, e.g. Chrome as recent as 75 */
gint64 port = g_ascii_strtoll (format, &endptr, 10);
if (endptr == format) {
/* conversion error */
return -1;
}
for (i = 0; i < gst_sdp_media_attributes_len (media); i++) {
const GstSDPAttribute *attr = gst_sdp_media_get_attribute (media, i);
if (g_strcmp0 (attr->key, "sctpmap") == 0 && atoi (attr->value) == port) {
/* a=sctpmap:5000 webrtc-datachannel 256 */
gchar **parts = g_strsplit (attr->value, " ", 3);
if (!parts[1] || g_strcmp0 (parts[1], "webrtc-datachannel") != 0) {
port = -1;
}
g_strfreev (parts);
return port;
}
}
}
return -1;
}
guint64
_get_sctp_max_message_size_from_media (const GstSDPMedia * media)
{
int i;
for (i = 0; i < gst_sdp_media_attributes_len (media); i++) {
const GstSDPAttribute *attr = gst_sdp_media_get_attribute (media, i);
if (g_strcmp0 (attr->key, "max-message-size") == 0)
return atoi (attr->value);
}
return 65536;
}
gboolean
_message_media_is_datachannel (const GstSDPMessage * msg, guint media_id)
{
const GstSDPMedia *media;
if (!msg)
return FALSE;
if (gst_sdp_message_medias_len (msg) <= media_id)
return FALSE;
media = gst_sdp_message_get_media (msg, media_id);
if (g_strcmp0 (gst_sdp_media_get_media (media), "application") != 0)
return FALSE;
if (gst_sdp_media_formats_len (media) != 1)
return FALSE;
if (g_strcmp0 (gst_sdp_media_get_format (media, 0),
"webrtc-datachannel") != 0)
return FALSE;
return TRUE;
}
guint
_message_get_datachannel_index (const GstSDPMessage * msg)
{
guint i;
for (i = 0; i < gst_sdp_message_medias_len (msg); i++) {
if (_message_media_is_datachannel (msg, i)) {
g_assert (i < G_MAXUINT);
return i;
}
}
return G_MAXUINT;
}
void
_get_ice_credentials_from_sdp_media (const GstSDPMessage * sdp, guint media_idx,
gchar ** ufrag, gchar ** pwd)
{
int i;
*ufrag = NULL;
*pwd = NULL;
{
/* search in the corresponding media section */
const GstSDPMedia *media = gst_sdp_message_get_media (sdp, media_idx);
const gchar *tmp_ufrag =
gst_sdp_media_get_attribute_val (media, "ice-ufrag");
const gchar *tmp_pwd = gst_sdp_media_get_attribute_val (media, "ice-pwd");
if (tmp_ufrag && tmp_pwd) {
*ufrag = g_strdup (tmp_ufrag);
*pwd = g_strdup (tmp_pwd);
return;
}
}
/* then in the sdp message itself */
for (i = 0; i < gst_sdp_message_attributes_len (sdp); i++) {
const GstSDPAttribute *attr = gst_sdp_message_get_attribute (sdp, i);
if (g_strcmp0 (attr->key, "ice-ufrag") == 0) {
g_assert (!*ufrag);
*ufrag = g_strdup (attr->value);
} else if (g_strcmp0 (attr->key, "ice-pwd") == 0) {
g_assert (!*pwd);
*pwd = g_strdup (attr->value);
}
}
if (!*ufrag && !*pwd) {
/* Check in the medias themselves. According to JSEP, they should be
* identical FIXME: only for bundle-d streams */
for (i = 0; i < gst_sdp_message_medias_len (sdp); i++) {
const GstSDPMedia *media = gst_sdp_message_get_media (sdp, i);
const gchar *tmp_ufrag =
gst_sdp_media_get_attribute_val (media, "ice-ufrag");
const gchar *tmp_pwd = gst_sdp_media_get_attribute_val (media, "ice-pwd");
if (tmp_ufrag && tmp_pwd) {
*ufrag = g_strdup (tmp_ufrag);
*pwd = g_strdup (tmp_pwd);
break;
}
}
}
}
gboolean
_parse_bundle (GstSDPMessage * sdp, GStrv * bundled)
{
const gchar *group;
gboolean ret = FALSE;
group = gst_sdp_message_get_attribute_val (sdp, "group");
if (group && g_str_has_prefix (group, "BUNDLE ")) {
*bundled = g_strsplit (group + strlen ("BUNDLE "), " ", 0);
if (!(*bundled)[0]) {
GST_ERROR ("Invalid format for BUNDLE group, expected at least "
"one mid (%s)", group);
g_strfreev (*bundled);
*bundled = NULL;
goto done;
}
} else {
ret = TRUE;
goto done;
}
ret = TRUE;
done:
return ret;
}
gboolean
_get_bundle_index (GstSDPMessage * sdp, GStrv bundled, guint * idx)
{
gboolean ret = FALSE;
guint i;
for (i = 0; i < gst_sdp_message_medias_len (sdp); i++) {
const GstSDPMedia *media = gst_sdp_message_get_media (sdp, i);
const gchar *mid = gst_sdp_media_get_attribute_val (media, "mid");
if (!g_strcmp0 (mid, bundled[0])) {
*idx = i;
ret = TRUE;
break;
}
}
return ret;
}