| 1 | /* |
| 2 | * RTMPE network protocol |
| 3 | * Copyright (c) 2008-2009 Andrej Stepanchuk |
| 4 | * Copyright (c) 2009-2010 Howard Chu |
| 5 | * Copyright (c) 2012 Samuel Pitoiset |
| 6 | * |
| 7 | * This file is part of FFmpeg. |
| 8 | * |
| 9 | * FFmpeg is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU Lesser General Public |
| 11 | * License as published by the Free Software Foundation; either |
| 12 | * version 2.1 of the License, or (at your option) any later version. |
| 13 | * |
| 14 | * FFmpeg is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 17 | * Lesser General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU Lesser General Public |
| 20 | * License along with FFmpeg; if not, write to the Free Software |
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 22 | */ |
| 23 | |
| 24 | /** |
| 25 | * @file |
| 26 | * RTMPE protocol |
| 27 | */ |
| 28 | |
| 29 | #include "libavutil/blowfish.h" |
| 30 | #include "libavutil/intreadwrite.h" |
| 31 | #include "libavutil/opt.h" |
| 32 | #include "libavutil/rc4.h" |
| 33 | #include "libavutil/xtea.h" |
| 34 | |
| 35 | #include "internal.h" |
| 36 | #include "rtmp.h" |
| 37 | #include "rtmpdh.h" |
| 38 | #include "rtmpcrypt.h" |
| 39 | #include "url.h" |
| 40 | |
| 41 | /* protocol handler context */ |
| 42 | typedef struct RTMPEContext { |
| 43 | const AVClass *class; |
| 44 | URLContext *stream; ///< TCP stream |
| 45 | FF_DH *dh; ///< Diffie-Hellman context |
| 46 | struct AVRC4 key_in; ///< RC4 key used for decrypt data |
| 47 | struct AVRC4 key_out; ///< RC4 key used for encrypt data |
| 48 | int handshaked; ///< flag indicating when the handshake is performed |
| 49 | int tunneling; ///< use a HTTP connection (RTMPTE) |
| 50 | } RTMPEContext; |
| 51 | |
| 52 | static const uint8_t rtmpe8_keys[16][16] = { |
| 53 | { 0xbf, 0xf0, 0x34, 0xb2, 0x11, 0xd9, 0x08, 0x1f, |
| 54 | 0xcc, 0xdf, 0xb7, 0x95, 0x74, 0x8d, 0xe7, 0x32 }, |
| 55 | { 0x08, 0x6a, 0x5e, 0xb6, 0x17, 0x43, 0x09, 0x0e, |
| 56 | 0x6e, 0xf0, 0x5a, 0xb8, 0xfe, 0x5a, 0x39, 0xe2 }, |
| 57 | { 0x7b, 0x10, 0x95, 0x6f, 0x76, 0xce, 0x05, 0x21, |
| 58 | 0x23, 0x88, 0xa7, 0x3a, 0x44, 0x01, 0x49, 0xa1 }, |
| 59 | { 0xa9, 0x43, 0xf3, 0x17, 0xeb, 0xf1, 0x1b, 0xb2, |
| 60 | 0xa6, 0x91, 0xa5, 0xee, 0x17, 0xf3, 0x63, 0x39 }, |
| 61 | { 0x7a, 0x30, 0xe0, 0x0a, 0xb5, 0x29, 0xe2, 0x2c, |
| 62 | 0xa0, 0x87, 0xae, 0xa5, 0xc0, 0xcb, 0x79, 0xac }, |
| 63 | { 0xbd, 0xce, 0x0c, 0x23, 0x2f, 0xeb, 0xde, 0xff, |
| 64 | 0x1c, 0xfa, 0xae, 0x16, 0x11, 0x23, 0x23, 0x9d }, |
| 65 | { 0x55, 0xdd, 0x3f, 0x7b, 0x77, 0xe7, 0xe6, 0x2e, |
| 66 | 0x9b, 0xb8, 0xc4, 0x99, 0xc9, 0x48, 0x1e, 0xe4 }, |
| 67 | { 0x40, 0x7b, 0xb6, 0xb4, 0x71, 0xe8, 0x91, 0x36, |
| 68 | 0xa7, 0xae, 0xbf, 0x55, 0xca, 0x33, 0xb8, 0x39 }, |
| 69 | { 0xfc, 0xf6, 0xbd, 0xc3, 0xb6, 0x3c, 0x36, 0x97, |
| 70 | 0x7c, 0xe4, 0xf8, 0x25, 0x04, 0xd9, 0x59, 0xb2 }, |
| 71 | { 0x28, 0xe0, 0x91, 0xfd, 0x41, 0x95, 0x4c, 0x4c, |
| 72 | 0x7f, 0xb7, 0xdb, 0x00, 0xe3, 0xa0, 0x66, 0xf8 }, |
| 73 | { 0x57, 0x84, 0x5b, 0x76, 0x4f, 0x25, 0x1b, 0x03, |
| 74 | 0x46, 0xd4, 0x5b, 0xcd, 0xa2, 0xc3, 0x0d, 0x29 }, |
| 75 | { 0x0a, 0xcc, 0xee, 0xf8, 0xda, 0x55, 0xb5, 0x46, |
| 76 | 0x03, 0x47, 0x34, 0x52, 0x58, 0x63, 0x71, 0x3b }, |
| 77 | { 0xb8, 0x20, 0x75, 0xdc, 0xa7, 0x5f, 0x1f, 0xee, |
| 78 | 0xd8, 0x42, 0x68, 0xe8, 0xa7, 0x2a, 0x44, 0xcc }, |
| 79 | { 0x07, 0xcf, 0x6e, 0x9e, 0xa1, 0x6d, 0x7b, 0x25, |
| 80 | 0x9f, 0xa7, 0xae, 0x6c, 0xd9, 0x2f, 0x56, 0x29 }, |
| 81 | { 0xfe, 0xb1, 0xea, 0xe4, 0x8c, 0x8c, 0x3c, 0xe1, |
| 82 | 0x4e, 0x00, 0x64, 0xa7, 0x6a, 0x38, 0x7c, 0x2a }, |
| 83 | { 0x89, 0x3a, 0x94, 0x27, 0xcc, 0x30, 0x13, 0xa2, |
| 84 | 0xf1, 0x06, 0x38, 0x5b, 0xa8, 0x29, 0xf9, 0x27 } |
| 85 | }; |
| 86 | |
| 87 | static const uint8_t rtmpe9_keys[16][24] = { |
| 88 | { 0x79, 0x34, 0x77, 0x4c, 0x67, 0xd1, 0x38, 0x3a, 0xdf, 0xb3, 0x56, 0xbe, |
| 89 | 0x8b, 0x7b, 0xd0, 0x24, 0x38, 0xe0, 0x73, 0x58, 0x41, 0x5d, 0x69, 0x67, }, |
| 90 | { 0x46, 0xf6, 0xb4, 0xcc, 0x01, 0x93, 0xe3, 0xa1, 0x9e, 0x7d, 0x3c, 0x65, |
| 91 | 0x55, 0x86, 0xfd, 0x09, 0x8f, 0xf7, 0xb3, 0xc4, 0x6f, 0x41, 0xca, 0x5c, }, |
| 92 | { 0x1a, 0xe7, 0xe2, 0xf3, 0xf9, 0x14, 0x79, 0x94, 0xc0, 0xd3, 0x97, 0x43, |
| 93 | 0x08, 0x7b, 0xb3, 0x84, 0x43, 0x2f, 0x9d, 0x84, 0x3f, 0x21, 0x01, 0x9b, }, |
| 94 | { 0xd3, 0xe3, 0x54, 0xb0, 0xf7, 0x1d, 0xf6, 0x2b, 0x5a, 0x43, 0x4d, 0x04, |
| 95 | 0x83, 0x64, 0x3e, 0x0d, 0x59, 0x2f, 0x61, 0xcb, 0xb1, 0x6a, 0x59, 0x0d, }, |
| 96 | { 0xc8, 0xc1, 0xe9, 0xb8, 0x16, 0x56, 0x99, 0x21, 0x7b, 0x5b, 0x36, 0xb7, |
| 97 | 0xb5, 0x9b, 0xdf, 0x06, 0x49, 0x2c, 0x97, 0xf5, 0x95, 0x48, 0x85, 0x7e, }, |
| 98 | { 0xeb, 0xe5, 0xe6, 0x2e, 0xa4, 0xba, 0xd4, 0x2c, 0xf2, 0x16, 0xe0, 0x8f, |
| 99 | 0x66, 0x23, 0xa9, 0x43, 0x41, 0xce, 0x38, 0x14, 0x84, 0x95, 0x00, 0x53, }, |
| 100 | { 0x66, 0xdb, 0x90, 0xf0, 0x3b, 0x4f, 0xf5, 0x6f, 0xe4, 0x9c, 0x20, 0x89, |
| 101 | 0x35, 0x5e, 0xd2, 0xb2, 0xc3, 0x9e, 0x9f, 0x7f, 0x63, 0xb2, 0x28, 0x81, }, |
| 102 | { 0xbb, 0x20, 0xac, 0xed, 0x2a, 0x04, 0x6a, 0x19, 0x94, 0x98, 0x9b, 0xc8, |
| 103 | 0xff, 0xcd, 0x93, 0xef, 0xc6, 0x0d, 0x56, 0xa7, 0xeb, 0x13, 0xd9, 0x30, }, |
| 104 | { 0xbc, 0xf2, 0x43, 0x82, 0x09, 0x40, 0x8a, 0x87, 0x25, 0x43, 0x6d, 0xe6, |
| 105 | 0xbb, 0xa4, 0xb9, 0x44, 0x58, 0x3f, 0x21, 0x7c, 0x99, 0xbb, 0x3f, 0x24, }, |
| 106 | { 0xec, 0x1a, 0xaa, 0xcd, 0xce, 0xbd, 0x53, 0x11, 0xd2, 0xfb, 0x83, 0xb6, |
| 107 | 0xc3, 0xba, 0xab, 0x4f, 0x62, 0x79, 0xe8, 0x65, 0xa9, 0x92, 0x28, 0x76, }, |
| 108 | { 0xc6, 0x0c, 0x30, 0x03, 0x91, 0x18, 0x2d, 0x7b, 0x79, 0xda, 0xe1, 0xd5, |
| 109 | 0x64, 0x77, 0x9a, 0x12, 0xc5, 0xb1, 0xd7, 0x91, 0x4f, 0x96, 0x4c, 0xa3, }, |
| 110 | { 0xd7, 0x7c, 0x2a, 0xbf, 0xa6, 0xe7, 0x85, 0x7c, 0x45, 0xad, 0xff, 0x12, |
| 111 | 0x94, 0xd8, 0xde, 0xa4, 0x5c, 0x3d, 0x79, 0xa4, 0x44, 0x02, 0x5d, 0x22, }, |
| 112 | { 0x16, 0x19, 0x0d, 0x81, 0x6a, 0x4c, 0xc7, 0xf8, 0xb8, 0xf9, 0x4e, 0xcd, |
| 113 | 0x2c, 0x9e, 0x90, 0x84, 0xb2, 0x08, 0x25, 0x60, 0xe1, 0x1e, 0xae, 0x18, }, |
| 114 | { 0xe9, 0x7c, 0x58, 0x26, 0x1b, 0x51, 0x9e, 0x49, 0x82, 0x60, 0x61, 0xfc, |
| 115 | 0xa0, 0xa0, 0x1b, 0xcd, 0xf5, 0x05, 0xd6, 0xa6, 0x6d, 0x07, 0x88, 0xa3, }, |
| 116 | { 0x2b, 0x97, 0x11, 0x8b, 0xd9, 0x4e, 0xd9, 0xdf, 0x20, 0xe3, 0x9c, 0x10, |
| 117 | 0xe6, 0xa1, 0x35, 0x21, 0x11, 0xf9, 0x13, 0x0d, 0x0b, 0x24, 0x65, 0xb2, }, |
| 118 | { 0x53, 0x6a, 0x4c, 0x54, 0xac, 0x8b, 0x9b, 0xb8, 0x97, 0x29, 0xfc, 0x60, |
| 119 | 0x2c, 0x5b, 0x3a, 0x85, 0x68, 0xb5, 0xaa, 0x6a, 0x44, 0xcd, 0x3f, 0xa7, }, |
| 120 | }; |
| 121 | |
| 122 | int ff_rtmpe_gen_pub_key(URLContext *h, uint8_t *buf) |
| 123 | { |
| 124 | RTMPEContext *rt = h->priv_data; |
| 125 | int offset, ret; |
| 126 | |
| 127 | if (!(rt->dh = ff_dh_init(1024))) |
| 128 | return AVERROR(ENOMEM); |
| 129 | |
| 130 | offset = ff_rtmp_calc_digest_pos(buf, 768, 632, 8); |
| 131 | if (offset < 0) |
| 132 | return offset; |
| 133 | |
| 134 | /* generate a Diffie-Hellmann public key */ |
| 135 | if ((ret = ff_dh_generate_public_key(rt->dh)) < 0) |
| 136 | return ret; |
| 137 | |
| 138 | /* write the public key into the handshake buffer */ |
| 139 | if ((ret = ff_dh_write_public_key(rt->dh, buf + offset, 128)) < 0) |
| 140 | return ret; |
| 141 | |
| 142 | return 0; |
| 143 | } |
| 144 | |
| 145 | int ff_rtmpe_compute_secret_key(URLContext *h, const uint8_t *serverdata, |
| 146 | const uint8_t *clientdata, int type) |
| 147 | { |
| 148 | RTMPEContext *rt = h->priv_data; |
| 149 | uint8_t secret_key[128], digest[32]; |
| 150 | int server_pos, client_pos; |
| 151 | int ret; |
| 152 | |
| 153 | if (type) { |
| 154 | if ((server_pos = ff_rtmp_calc_digest_pos(serverdata, 1532, 632, 772)) < 0) |
| 155 | return server_pos; |
| 156 | } else { |
| 157 | if ((server_pos = ff_rtmp_calc_digest_pos(serverdata, 768, 632, 8)) < 0) |
| 158 | return server_pos; |
| 159 | } |
| 160 | |
| 161 | if ((client_pos = ff_rtmp_calc_digest_pos(clientdata, 768, 632, 8)) < 0) |
| 162 | return client_pos; |
| 163 | |
| 164 | /* compute the shared secret secret in order to compute RC4 keys */ |
| 165 | if ((ret = ff_dh_compute_shared_secret_key(rt->dh, serverdata + server_pos, |
| 166 | 128, secret_key)) < 0) |
| 167 | return ret; |
| 168 | |
| 169 | /* set output key */ |
| 170 | if ((ret = ff_rtmp_calc_digest(serverdata + server_pos, 128, 0, secret_key, |
| 171 | 128, digest)) < 0) |
| 172 | return ret; |
| 173 | av_rc4_init(&rt->key_out, digest, 16 * 8, 1); |
| 174 | |
| 175 | /* set input key */ |
| 176 | if ((ret = ff_rtmp_calc_digest(clientdata + client_pos, 128, 0, secret_key, |
| 177 | 128, digest)) < 0) |
| 178 | return ret; |
| 179 | av_rc4_init(&rt->key_in, digest, 16 * 8, 1); |
| 180 | |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | static void rtmpe8_sig(const uint8_t *in, uint8_t *out, int key_id) |
| 185 | { |
| 186 | struct AVXTEA ctx; |
| 187 | |
| 188 | av_xtea_init(&ctx, rtmpe8_keys[key_id]); |
| 189 | av_xtea_crypt(&ctx, out, in, 1, NULL, 0); |
| 190 | } |
| 191 | |
| 192 | static void rtmpe9_sig(const uint8_t *in, uint8_t *out, int key_id) |
| 193 | { |
| 194 | struct AVBlowfish ctx; |
| 195 | uint32_t xl, xr; |
| 196 | |
| 197 | xl = AV_RL32(in); |
| 198 | xr = AV_RL32(in + 4); |
| 199 | |
| 200 | av_blowfish_init(&ctx, rtmpe9_keys[key_id], 24); |
| 201 | av_blowfish_crypt_ecb(&ctx, &xl, &xr, 0); |
| 202 | |
| 203 | AV_WL32(out, xl); |
| 204 | AV_WL32(out + 4, xr); |
| 205 | } |
| 206 | |
| 207 | void ff_rtmpe_encrypt_sig(URLContext *h, uint8_t *sig, const uint8_t *digest, |
| 208 | int type) |
| 209 | { |
| 210 | int i; |
| 211 | |
| 212 | for (i = 0; i < 32; i += 8) { |
| 213 | if (type == 8) { |
| 214 | /* RTMPE type 8 uses XTEA on the signature */ |
| 215 | rtmpe8_sig(sig + i, sig + i, digest[i] % 15); |
| 216 | } else if (type == 9) { |
| 217 | /* RTMPE type 9 uses Blowfish on the signature */ |
| 218 | rtmpe9_sig(sig + i, sig + i, digest[i] % 15); |
| 219 | } |
| 220 | } |
| 221 | } |
| 222 | |
| 223 | int ff_rtmpe_update_keystream(URLContext *h) |
| 224 | { |
| 225 | RTMPEContext *rt = h->priv_data; |
| 226 | char buf[RTMP_HANDSHAKE_PACKET_SIZE]; |
| 227 | |
| 228 | /* skip past 1536 bytes of the RC4 bytestream */ |
| 229 | av_rc4_crypt(&rt->key_in, buf, NULL, sizeof(buf), NULL, 1); |
| 230 | av_rc4_crypt(&rt->key_out, buf, NULL, sizeof(buf), NULL, 1); |
| 231 | |
| 232 | /* the next requests will be encrypted using RC4 keys */ |
| 233 | rt->handshaked = 1; |
| 234 | |
| 235 | return 0; |
| 236 | } |
| 237 | |
| 238 | static int rtmpe_close(URLContext *h) |
| 239 | { |
| 240 | RTMPEContext *rt = h->priv_data; |
| 241 | |
| 242 | ff_dh_free(rt->dh); |
| 243 | ffurl_close(rt->stream); |
| 244 | |
| 245 | return 0; |
| 246 | } |
| 247 | |
| 248 | static int rtmpe_open(URLContext *h, const char *uri, int flags) |
| 249 | { |
| 250 | RTMPEContext *rt = h->priv_data; |
| 251 | char host[256], url[1024]; |
| 252 | int ret, port; |
| 253 | |
| 254 | av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port, NULL, 0, uri); |
| 255 | |
| 256 | if (rt->tunneling) { |
| 257 | if (port < 0) |
| 258 | port = 80; |
| 259 | ff_url_join(url, sizeof(url), "ffrtmphttp", NULL, host, port, NULL); |
| 260 | } else { |
| 261 | if (port < 0) |
| 262 | port = 1935; |
| 263 | ff_url_join(url, sizeof(url), "tcp", NULL, host, port, NULL); |
| 264 | } |
| 265 | |
| 266 | /* open the tcp or ffrtmphttp connection */ |
| 267 | if ((ret = ffurl_open(&rt->stream, url, AVIO_FLAG_READ_WRITE, |
| 268 | &h->interrupt_callback, NULL)) < 0) { |
| 269 | rtmpe_close(h); |
| 270 | return ret; |
| 271 | } |
| 272 | |
| 273 | return 0; |
| 274 | } |
| 275 | |
| 276 | static int rtmpe_read(URLContext *h, uint8_t *buf, int size) |
| 277 | { |
| 278 | RTMPEContext *rt = h->priv_data; |
| 279 | int ret; |
| 280 | |
| 281 | rt->stream->flags |= h->flags & AVIO_FLAG_NONBLOCK; |
| 282 | ret = ffurl_read(rt->stream, buf, size); |
| 283 | rt->stream->flags &= ~AVIO_FLAG_NONBLOCK; |
| 284 | |
| 285 | if (ret < 0 && ret != AVERROR_EOF) |
| 286 | return ret; |
| 287 | |
| 288 | if (rt->handshaked && ret > 0) { |
| 289 | /* decrypt data received by the server */ |
| 290 | av_rc4_crypt(&rt->key_in, buf, buf, ret, NULL, 1); |
| 291 | } |
| 292 | |
| 293 | return ret; |
| 294 | } |
| 295 | |
| 296 | static int rtmpe_write(URLContext *h, const uint8_t *buf, int size) |
| 297 | { |
| 298 | RTMPEContext *rt = h->priv_data; |
| 299 | int ret; |
| 300 | |
| 301 | if (rt->handshaked) { |
| 302 | /* encrypt data to send to the server */ |
| 303 | av_rc4_crypt(&rt->key_out, buf, buf, size, NULL, 1); |
| 304 | } |
| 305 | |
| 306 | if ((ret = ffurl_write(rt->stream, buf, size)) < 0) |
| 307 | return ret; |
| 308 | |
| 309 | return size; |
| 310 | } |
| 311 | |
| 312 | #define OFFSET(x) offsetof(RTMPEContext, x) |
| 313 | #define DEC AV_OPT_FLAG_DECODING_PARAM |
| 314 | |
| 315 | static const AVOption ffrtmpcrypt_options[] = { |
| 316 | {"ffrtmpcrypt_tunneling", "Use a HTTP tunneling connection (RTMPTE).", OFFSET(tunneling), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC}, |
| 317 | { NULL }, |
| 318 | }; |
| 319 | |
| 320 | static const AVClass ffrtmpcrypt_class = { |
| 321 | .class_name = "ffrtmpcrypt", |
| 322 | .item_name = av_default_item_name, |
| 323 | .option = ffrtmpcrypt_options, |
| 324 | .version = LIBAVUTIL_VERSION_INT, |
| 325 | }; |
| 326 | |
| 327 | URLProtocol ff_ffrtmpcrypt_protocol = { |
| 328 | .name = "ffrtmpcrypt", |
| 329 | .url_open = rtmpe_open, |
| 330 | .url_read = rtmpe_read, |
| 331 | .url_write = rtmpe_write, |
| 332 | .url_close = rtmpe_close, |
| 333 | .priv_data_size = sizeof(RTMPEContext), |
| 334 | .flags = URL_PROTOCOL_FLAG_NETWORK, |
| 335 | .priv_data_class = &ffrtmpcrypt_class, |
| 336 | }; |