/* * RTMPE network protocol * Copyright (c) 2008-2009 Andrej Stepanchuk * Copyright (c) 2009-2010 Howard Chu * Copyright (c) 2012 Samuel Pitoiset * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * RTMPE protocol */ #include "libavutil/blowfish.h" #include "libavutil/intreadwrite.h" #include "libavutil/opt.h" #include "libavutil/rc4.h" #include "libavutil/xtea.h" #include "internal.h" #include "rtmp.h" #include "rtmpdh.h" #include "rtmpcrypt.h" #include "url.h" /* protocol handler context */ typedef struct RTMPEContext { const AVClass *class; URLContext *stream; ///< TCP stream FF_DH *dh; ///< Diffie-Hellman context struct AVRC4 key_in; ///< RC4 key used for decrypt data struct AVRC4 key_out; ///< RC4 key used for encrypt data int handshaked; ///< flag indicating when the handshake is performed int tunneling; ///< use a HTTP connection (RTMPTE) } RTMPEContext; static const uint8_t rtmpe8_keys[16][16] = { { 0xb2, 0x34, 0xf0, 0xbf, 0x1f, 0x08, 0xd9, 0x11, 0x95, 0xb7, 0xdf, 0xcc, 0x32, 0xe7, 0x8d, 0x74 }, { 0xb6, 0x5e, 0x6a, 0x08, 0x0e, 0x09, 0x43, 0x17, 0xb8, 0x5a, 0xf0, 0x6e, 0xe2, 0x39, 0x5a, 0xfe }, { 0x6f, 0x95, 0x10, 0x7b, 0x21, 0x05, 0xce, 0x76, 0x3a, 0xa7, 0x88, 0x23, 0xa1, 0x49, 0x01, 0x44 }, { 0x17, 0xf3, 0x43, 0xa9, 0xb2, 0x1b, 0xf1, 0xeb, 0xee, 0xa5, 0x91, 0xa6, 0x39, 0x63, 0xf3, 0x17 }, { 0x0a, 0xe0, 0x30, 0x7a, 0x2c, 0xe2, 0x29, 0xb5, 0xa5, 0xae, 0x87, 0xa0, 0xac, 0x79, 0xcb, 0xc0 }, { 0x23, 0x0c, 0xce, 0xbd, 0xff, 0xde, 0xeb, 0x2f, 0x16, 0xae, 0xfa, 0x1c, 0x9d, 0x23, 0x23, 0x11 }, { 0x7b, 0x3f, 0xdd, 0x55, 0x2e, 0xe6, 0xe7, 0x77, 0x99, 0xc4, 0xb8, 0x9b, 0xe4, 0x1e, 0x48, 0xc9 }, { 0xb4, 0xb6, 0x7b, 0x40, 0x36, 0x91, 0xe8, 0x71, 0x55, 0xbf, 0xae, 0xa7, 0x39, 0xb8, 0x33, 0xca }, { 0xc3, 0xbd, 0xf6, 0xfc, 0x97, 0x36, 0x3c, 0xb6, 0x25, 0xf8, 0xe4, 0x7c, 0xb2, 0x59, 0xd9, 0x04 }, { 0xfd, 0x91, 0xe0, 0x28, 0x4c, 0x4c, 0x95, 0x41, 0x00, 0xdb, 0xb7, 0x7f, 0xf8, 0x66, 0xa0, 0xe3 }, { 0x76, 0x5b, 0x84, 0x57, 0x03, 0x1b, 0x25, 0x4f, 0xcd, 0x5b, 0xd4, 0x46, 0x29, 0x0d, 0xc3, 0xa2 }, { 0xf8, 0xee, 0xcc, 0x0a, 0x46, 0xb5, 0x55, 0xda, 0x52, 0x34, 0x47, 0x03, 0x3b, 0x71, 0x63, 0x58 }, { 0xdc, 0x75, 0x20, 0xb8, 0xee, 0x1f, 0x5f, 0xa7, 0xe8, 0x68, 0x42, 0xd8, 0xcc, 0x44, 0x2a, 0xa7 }, { 0x9e, 0x6e, 0xcf, 0x07, 0x25, 0x7b, 0x6d, 0xa1, 0x6c, 0xae, 0xa7, 0x9f, 0x29, 0x56, 0x2f, 0xd9 }, { 0xe4, 0xea, 0xb1, 0xfe, 0xe1, 0x3c, 0x8c, 0x8c, 0xa7, 0x64, 0x00, 0x4e, 0x2a, 0x7c, 0x38, 0x6a }, { 0x27, 0x94, 0x3a, 0x89, 0xa2, 0x13, 0x30, 0xcc, 0x5b, 0x38, 0x06, 0xf1, 0x27, 0xf9, 0x29, 0xa8 } }; static const uint8_t rtmpe9_keys[16][24] = { { 0x79, 0x34, 0x77, 0x4c, 0x67, 0xd1, 0x38, 0x3a, 0xdf, 0xb3, 0x56, 0xbe, 0x8b, 0x7b, 0xd0, 0x24, 0x38, 0xe0, 0x73, 0x58, 0x41, 0x5d, 0x69, 0x67, }, { 0x46, 0xf6, 0xb4, 0xcc, 0x01, 0x93, 0xe3, 0xa1, 0x9e, 0x7d, 0x3c, 0x65, 0x55, 0x86, 0xfd, 0x09, 0x8f, 0xf7, 0xb3, 0xc4, 0x6f, 0x41, 0xca, 0x5c, }, { 0x1a, 0xe7, 0xe2, 0xf3, 0xf9, 0x14, 0x79, 0x94, 0xc0, 0xd3, 0x97, 0x43, 0x08, 0x7b, 0xb3, 0x84, 0x43, 0x2f, 0x9d, 0x84, 0x3f, 0x21, 0x01, 0x9b, }, { 0xd3, 0xe3, 0x54, 0xb0, 0xf7, 0x1d, 0xf6, 0x2b, 0x5a, 0x43, 0x4d, 0x04, 0x83, 0x64, 0x3e, 0x0d, 0x59, 0x2f, 0x61, 0xcb, 0xb1, 0x6a, 0x59, 0x0d, }, { 0xc8, 0xc1, 0xe9, 0xb8, 0x16, 0x56, 0x99, 0x21, 0x7b, 0x5b, 0x36, 0xb7, 0xb5, 0x9b, 0xdf, 0x06, 0x49, 0x2c, 0x97, 0xf5, 0x95, 0x48, 0x85, 0x7e, }, { 0xeb, 0xe5, 0xe6, 0x2e, 0xa4, 0xba, 0xd4, 0x2c, 0xf2, 0x16, 0xe0, 0x8f, 0x66, 0x23, 0xa9, 0x43, 0x41, 0xce, 0x38, 0x14, 0x84, 0x95, 0x00, 0x53, }, { 0x66, 0xdb, 0x90, 0xf0, 0x3b, 0x4f, 0xf5, 0x6f, 0xe4, 0x9c, 0x20, 0x89, 0x35, 0x5e, 0xd2, 0xb2, 0xc3, 0x9e, 0x9f, 0x7f, 0x63, 0xb2, 0x28, 0x81, }, { 0xbb, 0x20, 0xac, 0xed, 0x2a, 0x04, 0x6a, 0x19, 0x94, 0x98, 0x9b, 0xc8, 0xff, 0xcd, 0x93, 0xef, 0xc6, 0x0d, 0x56, 0xa7, 0xeb, 0x13, 0xd9, 0x30, }, { 0xbc, 0xf2, 0x43, 0x82, 0x09, 0x40, 0x8a, 0x87, 0x25, 0x43, 0x6d, 0xe6, 0xbb, 0xa4, 0xb9, 0x44, 0x58, 0x3f, 0x21, 0x7c, 0x99, 0xbb, 0x3f, 0x24, }, { 0xec, 0x1a, 0xaa, 0xcd, 0xce, 0xbd, 0x53, 0x11, 0xd2, 0xfb, 0x83, 0xb6, 0xc3, 0xba, 0xab, 0x4f, 0x62, 0x79, 0xe8, 0x65, 0xa9, 0x92, 0x28, 0x76, }, { 0xc6, 0x0c, 0x30, 0x03, 0x91, 0x18, 0x2d, 0x7b, 0x79, 0xda, 0xe1, 0xd5, 0x64, 0x77, 0x9a, 0x12, 0xc5, 0xb1, 0xd7, 0x91, 0x4f, 0x96, 0x4c, 0xa3, }, { 0xd7, 0x7c, 0x2a, 0xbf, 0xa6, 0xe7, 0x85, 0x7c, 0x45, 0xad, 0xff, 0x12, 0x94, 0xd8, 0xde, 0xa4, 0x5c, 0x3d, 0x79, 0xa4, 0x44, 0x02, 0x5d, 0x22, }, { 0x16, 0x19, 0x0d, 0x81, 0x6a, 0x4c, 0xc7, 0xf8, 0xb8, 0xf9, 0x4e, 0xcd, 0x2c, 0x9e, 0x90, 0x84, 0xb2, 0x08, 0x25, 0x60, 0xe1, 0x1e, 0xae, 0x18, }, { 0xe9, 0x7c, 0x58, 0x26, 0x1b, 0x51, 0x9e, 0x49, 0x82, 0x60, 0x61, 0xfc, 0xa0, 0xa0, 0x1b, 0xcd, 0xf5, 0x05, 0xd6, 0xa6, 0x6d, 0x07, 0x88, 0xa3, }, { 0x2b, 0x97, 0x11, 0x8b, 0xd9, 0x4e, 0xd9, 0xdf, 0x20, 0xe3, 0x9c, 0x10, 0xe6, 0xa1, 0x35, 0x21, 0x11, 0xf9, 0x13, 0x0d, 0x0b, 0x24, 0x65, 0xb2, }, { 0x53, 0x6a, 0x4c, 0x54, 0xac, 0x8b, 0x9b, 0xb8, 0x97, 0x29, 0xfc, 0x60, 0x2c, 0x5b, 0x3a, 0x85, 0x68, 0xb5, 0xaa, 0x6a, 0x44, 0xcd, 0x3f, 0xa7, }, }; int ff_rtmpe_gen_pub_key(URLContext *h, uint8_t *buf) { RTMPEContext *rt = h->priv_data; int offset, ret; if (!(rt->dh = ff_dh_init(1024))) return AVERROR(ENOMEM); offset = ff_rtmp_calc_digest_pos(buf, 768, 632, 8); if (offset < 0) return offset; /* generate a Diffie-Hellmann public key */ if ((ret = ff_dh_generate_public_key(rt->dh)) < 0) return ret; /* write the public key into the handshake buffer */ if ((ret = ff_dh_write_public_key(rt->dh, buf + offset, 128)) < 0) return ret; return 0; } int ff_rtmpe_compute_secret_key(URLContext *h, const uint8_t *serverdata, const uint8_t *clientdata, int type) { RTMPEContext *rt = h->priv_data; uint8_t secret_key[128], digest[32]; int server_pos, client_pos; int ret; if (type) { if ((server_pos = ff_rtmp_calc_digest_pos(serverdata, 1532, 632, 772)) < 0) return server_pos; } else { if ((server_pos = ff_rtmp_calc_digest_pos(serverdata, 768, 632, 8)) < 0) return server_pos; } if ((client_pos = ff_rtmp_calc_digest_pos(clientdata, 768, 632, 8)) < 0) return client_pos; /* compute the shared secret secret in order to compute RC4 keys */ if ((ret = ff_dh_compute_shared_secret_key(rt->dh, serverdata + server_pos, 128, secret_key, sizeof(secret_key))) < 0) return ret; /* set output key */ if ((ret = ff_rtmp_calc_digest(serverdata + server_pos, 128, 0, secret_key, 128, digest)) < 0) return ret; av_rc4_init(&rt->key_out, digest, 16 * 8, 1); /* set input key */ if ((ret = ff_rtmp_calc_digest(clientdata + client_pos, 128, 0, secret_key, 128, digest)) < 0) return ret; av_rc4_init(&rt->key_in, digest, 16 * 8, 1); return 0; } static void rtmpe8_sig(const uint8_t *in, uint8_t *out, int key_id) { struct AVXTEA ctx; av_xtea_le_init(&ctx, rtmpe8_keys[key_id]); av_xtea_le_crypt(&ctx, out, in, 1, NULL, 0); } static void rtmpe9_sig(const uint8_t *in, uint8_t *out, int key_id) { struct AVBlowfish ctx; uint32_t xl, xr; xl = AV_RL32(in); xr = AV_RL32(in + 4); av_blowfish_init(&ctx, rtmpe9_keys[key_id], 24); av_blowfish_crypt_ecb(&ctx, &xl, &xr, 0); AV_WL32(out, xl); AV_WL32(out + 4, xr); } void ff_rtmpe_encrypt_sig(URLContext *h, uint8_t *sig, const uint8_t *digest, int type) { int i; for (i = 0; i < 32; i += 8) { if (type == 8) { /* RTMPE type 8 uses XTEA on the signature */ rtmpe8_sig(sig + i, sig + i, digest[i] % 15); } else if (type == 9) { /* RTMPE type 9 uses Blowfish on the signature */ rtmpe9_sig(sig + i, sig + i, digest[i] % 15); } } } int ff_rtmpe_update_keystream(URLContext *h) { RTMPEContext *rt = h->priv_data; char buf[RTMP_HANDSHAKE_PACKET_SIZE]; /* skip past 1536 bytes of the RC4 bytestream */ av_rc4_crypt(&rt->key_in, buf, NULL, sizeof(buf), NULL, 1); av_rc4_crypt(&rt->key_out, buf, NULL, sizeof(buf), NULL, 1); /* the next requests will be encrypted using RC4 keys */ rt->handshaked = 1; return 0; } static int rtmpe_close(URLContext *h) { RTMPEContext *rt = h->priv_data; ff_dh_free(rt->dh); ffurl_close(rt->stream); return 0; } static int rtmpe_open(URLContext *h, const char *uri, int flags) { RTMPEContext *rt = h->priv_data; char host[256], url[1024]; int ret, port; av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port, NULL, 0, uri); if (rt->tunneling) { if (port < 0) port = 80; ff_url_join(url, sizeof(url), "ffrtmphttp", NULL, host, port, NULL); } else { if (port < 0) port = 1935; ff_url_join(url, sizeof(url), "tcp", NULL, host, port, NULL); } /* open the tcp or ffrtmphttp connection */ if ((ret = ffurl_open(&rt->stream, url, AVIO_FLAG_READ_WRITE, &h->interrupt_callback, NULL, h->protocols, h)) < 0) { rtmpe_close(h); return ret; } return 0; } static int rtmpe_read(URLContext *h, uint8_t *buf, int size) { RTMPEContext *rt = h->priv_data; int ret; rt->stream->flags |= h->flags & AVIO_FLAG_NONBLOCK; ret = ffurl_read(rt->stream, buf, size); rt->stream->flags &= ~AVIO_FLAG_NONBLOCK; if (ret < 0 && ret != AVERROR_EOF) return ret; if (rt->handshaked && ret > 0) { /* decrypt data received by the server */ av_rc4_crypt(&rt->key_in, buf, buf, ret, NULL, 1); } return ret; } static int rtmpe_write(URLContext *h, const uint8_t *buf, int size) { RTMPEContext *rt = h->priv_data; int ret; if (rt->handshaked) { /* encrypt data to send to the server */ av_rc4_crypt(&rt->key_out, buf, buf, size, NULL, 1); } if ((ret = ffurl_write(rt->stream, buf, size)) < 0) return ret; return size; } #define OFFSET(x) offsetof(RTMPEContext, x) #define DEC AV_OPT_FLAG_DECODING_PARAM static const AVOption ffrtmpcrypt_options[] = { {"ffrtmpcrypt_tunneling", "Use a HTTP tunneling connection (RTMPTE).", OFFSET(tunneling), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC}, { NULL }, }; static const AVClass ffrtmpcrypt_class = { .class_name = "ffrtmpcrypt", .item_name = av_default_item_name, .option = ffrtmpcrypt_options, .version = LIBAVUTIL_VERSION_INT, }; const URLProtocol ff_ffrtmpcrypt_protocol = { .name = "ffrtmpcrypt", .url_open = rtmpe_open, .url_read = rtmpe_read, .url_write = rtmpe_write, .url_close = rtmpe_close, .priv_data_size = sizeof(RTMPEContext), .flags = URL_PROTOCOL_FLAG_NETWORK, .priv_data_class = &ffrtmpcrypt_class, };