FFmpeg
srtpproto.c
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1 /*
2  * SRTP network protocol
3  * Copyright (c) 2012 Martin Storsjo
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/opt.h"
23 #include "avformat.h"
24 #include "url.h"
25 
26 #include "rtpdec.h"
27 #include "srtp.h"
28 
29 typedef struct SRTPProtoContext {
30  const AVClass *class;
32  const char *out_suite, *out_params;
33  const char *in_suite, *in_params;
34  struct SRTPContext srtp_out, srtp_in;
37 
38 #define D AV_OPT_FLAG_DECODING_PARAM
39 #define E AV_OPT_FLAG_ENCODING_PARAM
40 static const AVOption options[] = {
41  { "srtp_out_suite", "", offsetof(SRTPProtoContext, out_suite), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
42  { "srtp_out_params", "", offsetof(SRTPProtoContext, out_params), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
43  { "srtp_in_suite", "", offsetof(SRTPProtoContext, in_suite), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
44  { "srtp_in_params", "", offsetof(SRTPProtoContext, in_params), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
45  { NULL }
46 };
47 
48 static const AVClass srtp_context_class = {
49  .class_name = "srtp",
50  .item_name = av_default_item_name,
51  .option = options,
52  .version = LIBAVUTIL_VERSION_INT,
53 };
54 
55 static int srtp_close(URLContext *h)
56 {
57  SRTPProtoContext *s = h->priv_data;
58  ff_srtp_free(&s->srtp_out);
59  ff_srtp_free(&s->srtp_in);
60  ffurl_closep(&s->rtp_hd);
61  return 0;
62 }
63 
64 static int srtp_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
65 {
66  SRTPProtoContext *s = h->priv_data;
67  char hostname[256], buf[1024], path[1024];
68  int rtp_port, ret;
69 
70  if (s->out_suite && s->out_params)
71  if ((ret = ff_srtp_set_crypto(&s->srtp_out, s->out_suite, s->out_params)) < 0)
72  goto fail;
73  if (s->in_suite && s->in_params)
74  if ((ret = ff_srtp_set_crypto(&s->srtp_in, s->in_suite, s->in_params)) < 0)
75  goto fail;
76 
77  av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &rtp_port,
78  path, sizeof(path), uri);
79  ff_url_join(buf, sizeof(buf), "rtp", NULL, hostname, rtp_port, "%s", path);
80  if ((ret = ffurl_open_whitelist(&s->rtp_hd, buf, flags, &h->interrupt_callback,
81  options, h->protocol_whitelist, h->protocol_blacklist, h)) < 0)
82  goto fail;
83 
84  h->max_packet_size = FFMIN(s->rtp_hd->max_packet_size,
85  sizeof(s->encryptbuf)) - 14;
86  h->is_streamed = 1;
87  return 0;
88 
89 fail:
90  srtp_close(h);
91  return ret;
92 }
93 
94 static int srtp_read(URLContext *h, uint8_t *buf, int size)
95 {
96  SRTPProtoContext *s = h->priv_data;
97  int ret;
98 start:
99  ret = ffurl_read(s->rtp_hd, buf, size);
100  if (ret > 0 && s->srtp_in.aes) {
101  if (ff_srtp_decrypt(&s->srtp_in, buf, &ret) < 0)
102  goto start;
103  }
104  return ret;
105 }
106 
107 static int srtp_write(URLContext *h, const uint8_t *buf, int size)
108 {
109  SRTPProtoContext *s = h->priv_data;
110  if (!s->srtp_out.aes)
111  return ffurl_write(s->rtp_hd, buf, size);
112  size = ff_srtp_encrypt(&s->srtp_out, buf, size, s->encryptbuf,
113  sizeof(s->encryptbuf));
114  if (size < 0)
115  return size;
116  return ffurl_write(s->rtp_hd, s->encryptbuf, size);
117 }
118 
120 {
121  SRTPProtoContext *s = h->priv_data;
122  return ffurl_get_file_handle(s->rtp_hd);
123 }
124 
125 static int srtp_get_multi_file_handle(URLContext *h, int **handles,
126  int *numhandles)
127 {
128  SRTPProtoContext *s = h->priv_data;
129  return ffurl_get_multi_file_handle(s->rtp_hd, handles, numhandles);
130 }
131 
133  .name = "srtp",
134  .url_open2 = srtp_open,
135  .url_read = srtp_read,
136  .url_write = srtp_write,
137  .url_close = srtp_close,
138  .url_get_file_handle = srtp_get_file_handle,
139  .url_get_multi_file_handle = srtp_get_multi_file_handle,
140  .priv_data_size = sizeof(SRTPProtoContext),
141  .priv_data_class = &srtp_context_class,
143 };
opt.h
SRTPProtoContext::encryptbuf
uint8_t encryptbuf[RTP_MAX_PACKET_LENGTH]
Definition: srtpproto.c:35
URL_PROTOCOL_FLAG_NETWORK
#define URL_PROTOCOL_FLAG_NETWORK
Definition: url.h:33
srtp_get_file_handle
static int srtp_get_file_handle(URLContext *h)
Definition: srtpproto.c:119
ffurl_write
static int ffurl_write(URLContext *h, const uint8_t *buf, int size)
Write size bytes from buf to the resource accessed by h.
Definition: url.h:202
E
#define E
Definition: srtpproto.c:39
AVOption
AVOption.
Definition: opt.h:429
srtp.h
srtp_context_class
static const AVClass srtp_context_class
Definition: srtpproto.c:48
AVDictionary
Definition: dict.c:34
SRTPContext
Definition: srtp.h:30
URLProtocol
Definition: url.h:51
srtp_read
static int srtp_read(URLContext *h, uint8_t *buf, int size)
Definition: srtpproto.c:94
fail
#define fail()
Definition: checkasm.h:189
ff_srtp_decrypt
int ff_srtp_decrypt(struct SRTPContext *s, uint8_t *buf, int *lenptr)
Definition: srtp.c:127
srtp_close
static int srtp_close(URLContext *h)
Definition: srtpproto.c:55
ff_srtp_encrypt
int ff_srtp_encrypt(struct SRTPContext *s, const uint8_t *in, int len, uint8_t *out, int outlen)
Definition: srtp.c:239
ffurl_open_whitelist
int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options, const char *whitelist, const char *blacklist, URLContext *parent)
Create an URLContext for accessing to the resource indicated by url, and open it.
Definition: avio.c:362
s
#define s(width, name)
Definition: cbs_vp9.c:198
SRTPProtoContext::out_params
const char * out_params
Definition: srtpproto.c:32
ff_url_join
int ff_url_join(char *str, int size, const char *proto, const char *authorization, const char *hostname, int port, const char *fmt,...)
Definition: url.c:40
ff_srtp_protocol
const URLProtocol ff_srtp_protocol
Definition: srtpproto.c:132
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:75
srtp_open
static int srtp_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
Definition: srtpproto.c:64
NULL
#define NULL
Definition: coverity.c:32
SRTPProtoContext::out_suite
const char * out_suite
Definition: srtpproto.c:32
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
options
Definition: swscale.c:42
rtpdec.h
D
#define D
Definition: srtpproto.c:38
ffurl_get_multi_file_handle
int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
Return the file descriptors associated with this URL.
Definition: avio.c:821
size
int size
Definition: twinvq_data.h:10344
URLProtocol::name
const char * name
Definition: url.h:52
SRTPProtoContext::in_params
const char * in_params
Definition: srtpproto.c:33
srtp_get_multi_file_handle
static int srtp_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
Definition: srtpproto.c:125
ff_srtp_free
void ff_srtp_free(struct SRTPContext *s)
Definition: srtp.c:32
srtp_write
static int srtp_write(URLContext *h, const uint8_t *buf, int size)
Definition: srtpproto.c:107
SRTPProtoContext::srtp_in
struct SRTPContext srtp_out srtp_in
Definition: srtpproto.c:34
URLContext
Definition: url.h:35
SRTPProtoContext::rtp_hd
URLContext * rtp_hd
Definition: srtpproto.c:31
av_url_split
void av_url_split(char *proto, int proto_size, char *authorization, int authorization_size, char *hostname, int hostname_size, int *port_ptr, char *path, int path_size, const char *url)
Split a URL string into components.
Definition: utils.c:351
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
url.h
ff_srtp_set_crypto
int ff_srtp_set_crypto(struct SRTPContext *s, const char *suite, const char *params)
Definition: srtp.c:66
ffurl_closep
int ffurl_closep(URLContext **hh)
Close the resource accessed by the URLContext h, and free the memory used by it.
Definition: avio.c:588
ret
ret
Definition: filter_design.txt:187
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:80
SRTPProtoContext::in_suite
const char * in_suite
Definition: srtpproto.c:33
SRTPProtoContext
Definition: srtpproto.c:29
avformat.h
RTP_MAX_PACKET_LENGTH
#define RTP_MAX_PACKET_LENGTH
Definition: rtpdec.h:37
options
static const AVOption options[]
Definition: srtpproto.c:40
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482
h
h
Definition: vp9dsp_template.c:2070
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Underlying C type is a uint8_t* that is either NULL or points to a C string allocated with the av_mal...
Definition: opt.h:276
ffurl_get_file_handle
int ffurl_get_file_handle(URLContext *h)
Return the file descriptor associated with this URL.
Definition: avio.c:814
ffurl_read
static int ffurl_read(URLContext *h, uint8_t *buf, int size)
Read up to size bytes from the resource accessed by h, and store the read bytes in buf.
Definition: url.h:181