github-mirrors/FFmpeg
1
0
Fork 0
mirror of https://mirror.skon.top/https://github.com/FFmpeg/FFmpeg synced 2026-04-20 21:00:41 +08:00
Code Issues Packages Projects Releases Wiki Activity

avformat/whip: add DTLS active role support

Browse Source 
Add dtls_active flag to specify the dtls role.

Properly set the send key and recv key depends on DTLS role:

As DTLS server, the recv key is client master key plus salt,
the send key is server master key plus salt.
As DTLS client, the recv key is server master key plus salt,
the send key is client master key plus salt.

Signed-off-by: Jack Lau <jacklau1222@qq.com>
This commit is contained in:
Jack Lau
2025-10-10 18:06:03 +08:00
committed by stevenliu
parent 535d4047d3
commit 0e8cff52bc
2 changed files with 34 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
doc/muxers.texi
View File

@@ -3959,6 +3959,14 @@ Default value is 1200.
Set the buffer size, in bytes, of underlying protocol.
Default value is -1(auto). The UDP auto selects a reasonable value.
@item whip_flags @var{flags}
Possible values:
@table @samp
@item dtls_active
The muxer will try to set dtls active role and send the first client hello.
@end table
@item authorization @var{string}
The optional Bearer token for WHIP Authorization.

37
libavformat/whip.c
View File

@@ -211,9 +211,14 @@ enum WHIPState {
WHIP_STATE_FAILED,
};
typedef enum WHIPFlags {
WHIP_DTLS_ACTIVE = (1 << 0),
} WHIPFlags;
typedef struct WHIPContext {
AVClass *av_class;
uint32_t flags;
/* The state of the RTC connection. */
enum WHIPState state;
@@ -599,6 +604,7 @@ static int generate_sdp_offer(AVFormatContext *s)
const char *acodec_name = NULL, *vcodec_name = NULL;
AVBPrint bp;
WHIPContext *whip = s->priv_data;
int is_dtls_active = whip->flags & WHIP_DTLS_ACTIVE;
/* To prevent a crash during cleanup, always initialize it. */
av_bprint_init(&bp, 1, MAX_SDP_SIZE);
@@ -644,7 +650,7 @@ static int generate_sdp_offer(AVFormatContext *s)
"a=ice-ufrag:%s\r\n"
"a=ice-pwd:%s\r\n"
"a=fingerprint:sha-256 %s\r\n"
"a=setup:passive\r\n"
"a=setup:%s\r\n"
"a=mid:0\r\n"
"a=sendonly\r\n"
"a=msid:FFmpeg audio\r\n"
@@ -656,6 +662,7 @@ static int generate_sdp_offer(AVFormatContext *s)
whip->ice_ufrag_local,
whip->ice_pwd_local,
whip->dtls_fingerprint,
is_dtls_active ? "active" : "passive",
whip->audio_payload_type,
acodec_name,
whip->audio_par->sample_rate,
@@ -679,7 +686,7 @@ static int generate_sdp_offer(AVFormatContext *s)
"a=ice-ufrag:%s\r\n"
"a=ice-pwd:%s\r\n"
"a=fingerprint:sha-256 %s\r\n"
"a=setup:passive\r\n"
"a=setup:%s\r\n"
"a=mid:1\r\n"
"a=sendonly\r\n"
"a=msid:FFmpeg video\r\n"
@@ -698,6 +705,7 @@ static int generate_sdp_offer(AVFormatContext *s)
whip->ice_ufrag_local,
whip->ice_pwd_local,
whip->dtls_fingerprint,
is_dtls_active ? "active" : "passive",
whip->video_payload_type,
vcodec_name,
whip->video_payload_type,
@@ -1250,6 +1258,7 @@ static int ice_dtls_handshake(AVFormatContext *s)
int ret = 0, size, i;
int64_t starttime = av_gettime_relative(), now;
WHIPContext *whip = s->priv_data;
int is_dtls_active = whip->flags & WHIP_DTLS_ACTIVE;
AVDictionary *opts = NULL;
char buf[256], *cert_buf = NULL, *key_buf = NULL;
@@ -1301,6 +1310,8 @@ next_packet:
av_usleep(ICE_DTLS_READ_SLEEP_DURATION * WHIP_US_PER_MS);
continue;
}
if (is_dtls_active)
break;
av_log(whip, AV_LOG_ERROR, "Failed to read message\n");
goto end;
}
@@ -1328,7 +1339,7 @@ next_packet:
av_dict_set(&opts, "key_pem", whip->key_buf, 0);
av_dict_set_int(&opts, "external_sock", 1, 0);
av_dict_set_int(&opts, "use_srtp", 1, 0);
av_dict_set_int(&opts, "listen", 1, 0);
av_dict_set_int(&opts, "listen", is_dtls_active ? 0 : 1, 0);
/* If got the first binding response, start DTLS handshake. */
ret = ffurl_open_whitelist(&whip->dtls_uc, buf, AVIO_FLAG_READ_WRITE, &s->interrupt_callback,
&opts, s->protocol_whitelist, s->protocol_blacklist, NULL);
@@ -1347,8 +1358,8 @@ next_packet:
goto next_packet;
}
/* If got any DTLS messages, handle it. */
if (is_dtls_packet(whip->buf, ret)) {
/* Handle DTLS handshake */
if (is_dtls_packet(whip->buf, ret) || is_dtls_active) {
/* Start consent timer when ICE selected */
whip->whip_last_consent_tx_time = whip->whip_last_consent_rx_time = av_gettime_relative();
whip->state = WHIP_STATE_ICE_CONNECTED;
@@ -1397,6 +1408,10 @@ static int setup_srtp(AVFormatContext *s)
*/
const char* suite = "SRTP_AES128_CM_HMAC_SHA1_80";
WHIPContext *whip = s->priv_data;
int is_dtls_active = whip->flags & WHIP_DTLS_ACTIVE;
char *cp = is_dtls_active ? send_key : recv_key;
char *sp = is_dtls_active ? recv_key : send_key;
ret = ff_dtls_export_materials(whip->dtls_uc, whip->dtls_srtp_materials, sizeof(whip->dtls_srtp_materials));
if (ret < 0)
goto end;
@@ -1411,13 +1426,11 @@ static int setup_srtp(AVFormatContext *s)
char *client_salt = server_key + DTLS_SRTP_KEY_LEN;
char *server_salt = client_salt + DTLS_SRTP_SALT_LEN;
/* As DTLS server, the recv key is client master key plus salt. */
memcpy(recv_key, client_key, DTLS_SRTP_KEY_LEN);
memcpy(recv_key + DTLS_SRTP_KEY_LEN, client_salt, DTLS_SRTP_SALT_LEN);
memcpy(cp, client_key, DTLS_SRTP_KEY_LEN);
memcpy(cp + DTLS_SRTP_KEY_LEN, client_salt, DTLS_SRTP_SALT_LEN);
/* As DTLS server, the send key is server master key plus salt. */
memcpy(send_key, server_key, DTLS_SRTP_KEY_LEN);
memcpy(send_key + DTLS_SRTP_KEY_LEN, server_salt, DTLS_SRTP_SALT_LEN);
memcpy(sp, server_key, DTLS_SRTP_KEY_LEN);
memcpy(sp + DTLS_SRTP_KEY_LEN, server_salt, DTLS_SRTP_SALT_LEN);
/* Setup SRTP context for outgoing packets */
if (!av_base64_encode(buf, sizeof(buf), send_key, sizeof(send_key))) {
@@ -2024,6 +2037,8 @@ static const AVOption options[] = {
{ "handshake_timeout", "Timeout in milliseconds for ICE and DTLS handshake.", OFFSET(handshake_timeout), AV_OPT_TYPE_INT, { .i64 = 5000 }, -1, INT_MAX, ENC },
{ "pkt_size", "The maximum size, in bytes, of RTP packets that send out", OFFSET(pkt_size), AV_OPT_TYPE_INT, { .i64 = 1200 }, -1, INT_MAX, ENC },
{ "buffer_size", "The buffer size, in bytes, of underlying protocol", OFFSET(buffer_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, ENC },
{ "whip_flags", "Set flags affecting WHIP connection behavior", OFFSET(flags), AV_OPT_TYPE_FLAGS, { .i64 = 0}, 0, UINT_MAX, ENC, .unit = "flags" },
{ "dtls_active", "Set dtls role as active", 0, AV_OPT_TYPE_CONST, { .i64 = WHIP_DTLS_ACTIVE}, 0, UINT_MAX, ENC, .unit = "flags" },
{ "authorization", "The optional Bearer token for WHIP Authorization", OFFSET(authorization), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, ENC },
{ "cert_file", "The optional certificate file path for DTLS", OFFSET(cert_file), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, ENC },
{ "key_file", "The optional private key file path for DTLS", OFFSET(key_file), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, ENC },