path: root/libavformat/srtpproto.c (plain)
blob: 5e6e5164d757fbbc1f3c144116c26d23673ec13b

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 "avio_internal.h"
25	#include "url.h"
26
27	#include "internal.h"
28	#include "rtpdec.h"
29	#include "srtp.h"
30
31	typedef struct SRTPProtoContext {
32	const AVClass *class;
33	URLContext *rtp_hd;
34	const char *out_suite, *out_params;
35	const char *in_suite, *in_params;
36	struct SRTPContext srtp_out, srtp_in;
37	uint8_t encryptbuf[RTP_MAX_PACKET_LENGTH];
38	} SRTPProtoContext;
39
40	#define D AV_OPT_FLAG_DECODING_PARAM
41	#define E AV_OPT_FLAG_ENCODING_PARAM
42	static const AVOption options[] = {
43	{ "srtp_out_suite", "", offsetof(SRTPProtoContext, out_suite), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
44	{ "srtp_out_params", "", offsetof(SRTPProtoContext, out_params), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
45	{ "srtp_in_suite", "", offsetof(SRTPProtoContext, in_suite), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
46	{ "srtp_in_params", "", offsetof(SRTPProtoContext, in_params), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
47	{ NULL }
48	};
49
50	static const AVClass srtp_context_class = {
51	.class_name = "srtp",
52	.item_name = av_default_item_name,
53	.option = options,
54	.version = LIBAVUTIL_VERSION_INT,
55	};
56
57	static int srtp_close(URLContext *h)
58	{
59	SRTPProtoContext *s = h->priv_data;
60	ff_srtp_free(&s->srtp_out);
61	ff_srtp_free(&s->srtp_in);
62	ffurl_close(s->rtp_hd);
63	s->rtp_hd = NULL;
64	return 0;
65	}
66
67	static int srtp_open(URLContext *h, const char *uri, int flags)
68	{
69	SRTPProtoContext *s = h->priv_data;
70	char hostname[256], buf[1024], path[1024];
71	int rtp_port, ret;
72
73	if (s->out_suite && s->out_params)
74	if ((ret = ff_srtp_set_crypto(&s->srtp_out, s->out_suite, s->out_params)) < 0)
75	goto fail;
76	if (s->in_suite && s->in_params)
77	if ((ret = ff_srtp_set_crypto(&s->srtp_in, s->in_suite, s->in_params)) < 0)
78	goto fail;
79
80	av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &rtp_port,
81	path, sizeof(path), uri);
82	ff_url_join(buf, sizeof(buf), "rtp", NULL, hostname, rtp_port, "%s", path);
83	if ((ret = ffurl_open_whitelist(&s->rtp_hd, buf, flags, &h->interrupt_callback,
84	NULL, h->protocol_whitelist, h->protocol_blacklist, h)) < 0)
85	goto fail;
86
87	h->max_packet_size = FFMIN(s->rtp_hd->max_packet_size,
88	sizeof(s->encryptbuf)) - 14;
89	h->is_streamed = 1;
90	return 0;
91
92	fail:
93	srtp_close(h);
94	return ret;
95	}
96
97	static int srtp_read(URLContext *h, uint8_t *buf, int size)
98	{
99	SRTPProtoContext *s = h->priv_data;
100	int ret;
101	start:
102	ret = ffurl_read(s->rtp_hd, buf, size);
103	if (ret > 0 && s->srtp_in.aes) {
104	if (ff_srtp_decrypt(&s->srtp_in, buf, &ret) < 0)
105	goto start;
106	}
107	return ret;
108	}
109
110	static int srtp_write(URLContext *h, const uint8_t *buf, int size)
111	{
112	SRTPProtoContext *s = h->priv_data;
113	if (!s->srtp_out.aes)
114	return ffurl_write(s->rtp_hd, buf, size);
115	size = ff_srtp_encrypt(&s->srtp_out, buf, size, s->encryptbuf,
116	sizeof(s->encryptbuf));
117	if (size < 0)
118	return size;
119	return ffurl_write(s->rtp_hd, s->encryptbuf, size);
120	}
121
122	static int srtp_get_file_handle(URLContext *h)
123	{
124	SRTPProtoContext *s = h->priv_data;
125	return ffurl_get_file_handle(s->rtp_hd);
126	}
127
128	static int srtp_get_multi_file_handle(URLContext *h, int **handles,
129	int *numhandles)
130	{
131	SRTPProtoContext *s = h->priv_data;
132	return ffurl_get_multi_file_handle(s->rtp_hd, handles, numhandles);
133	}
134
135	const URLProtocol ff_srtp_protocol = {
136	.name = "srtp",
137	.url_open = srtp_open,
138	.url_read = srtp_read,
139	.url_write = srtp_write,
140	.url_close = srtp_close,
141	.url_get_file_handle = srtp_get_file_handle,
142	.url_get_multi_file_handle = srtp_get_multi_file_handle,
143	.priv_data_size = sizeof(SRTPProtoContext),
144	.priv_data_class = &srtp_context_class,
145	.flags = URL_PROTOCOL_FLAG_NETWORK,
146	};
147