| 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, E }, |
| 46 | { "srtp_in_params", "", offsetof(SRTPProtoContext, in_params), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E }, |
| 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(&s->rtp_hd, buf, flags, &h->interrupt_callback, NULL)) < 0) |
| 84 | goto fail; |
| 85 | |
| 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; |
| 90 | |
| 91 | fail: |
| 92 | srtp_close(h); |
| 93 | return ret; |
| 94 | } |
| 95 | |
| 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 | }; |