FFmpeg: libavformat/srtpproto.c Source File

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libavformat

srtpproto.c

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1 /*

2 * SRTP network protocol

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 */

22 #include "libavutil/opt.h"

23 #include "avformat.h"

24 #include "avio_internal.h"

25 #include "url.h"

27 #include "internal.h"

28 #include "rtpdec.h"

29 #include "srtp.h"

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;

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, E },

46 { "srtp_in_params", "", offsetof(SRTPProtoContext, in_params), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },

47 { NULL }

48 };

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 };

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 }

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;

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;

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(&s->rtp_hd, buf, flags, &h->interrupt_callback, NULL)) < 0)

84 goto fail;

86 h->max_packet_size = FFMIN(s->rtp_hd->max_packet_size,

87 sizeof(s->encryptbuf)) - 14;

88 h->is_streamed = 1;

89 return 0;

91 fail:

92 srtp_close(h);

93 return ret;

94 }

96 static int srtp_read(URLContext *h, uint8_t *buf, int size)

97 {

98 SRTPProtoContext *s = h->priv_data;

99 int ret;

100 start:

101 ret = ffurl_read(s->rtp_hd, buf, size);

102 if (ret > 0 && s->srtp_in.aes) {

103 if (ff_srtp_decrypt(&s->srtp_in, buf, &ret) < 0)

104 goto start;

105 }

106 return ret;

107 }

108

109 static int srtp_write(URLContext *h, const uint8_t *buf, int size)

110 {

111 SRTPProtoContext *s = h->priv_data;

112 if (!s->srtp_out.aes)

113 return ffurl_write(s->rtp_hd, buf, size);

114 size = ff_srtp_encrypt(&s->srtp_out, buf, size, s->encryptbuf,

115 sizeof(s->encryptbuf));

116 if (size < 0)

117 return size;

118 return ffurl_write(s->rtp_hd, s->encryptbuf, size);

119 }

120

121 static int srtp_get_file_handle(URLContext *h)

122 {

123 SRTPProtoContext *s = h->priv_data;

124 return ffurl_get_file_handle(s->rtp_hd);

125 }

126

127 static int srtp_get_multi_file_handle(URLContext *h, int **handles,

128 int *numhandles)

129 {

130 SRTPProtoContext *s = h->priv_data;

131 return ffurl_get_multi_file_handle(s->rtp_hd, handles, numhandles);

132 }

133

134 URLProtocol ff_srtp_protocol = {

135 .name = "srtp",

136 .url_open = srtp_open,

137 .url_read = srtp_read,

138 .url_write = srtp_write,

139 .url_close = srtp_close,

140 .url_get_file_handle = srtp_get_file_handle,

141 .url_get_multi_file_handle = srtp_get_multi_file_handle,

142 .priv_data_size = sizeof(SRTPProtoContext),

143 .priv_data_class = &srtp_context_class,

144 .flags = URL_PROTOCOL_FLAG_NETWORK,

145 };

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