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 */ 42typedef 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 52static 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 87static 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 122int 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 145int 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 184static 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 192static 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 207void 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 223int 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 238static 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 248static 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 276static 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 296static 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 315static 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 320static 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 327URLProtocol 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}; 337