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path: root/libavformat/rtmpcrypt.c (plain)
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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 { 0xb2, 0x34, 0xf0, 0xbf, 0x1f, 0x08, 0xd9, 0x11,
54 0x95, 0xb7, 0xdf, 0xcc, 0x32, 0xe7, 0x8d, 0x74 },
55 { 0xb6, 0x5e, 0x6a, 0x08, 0x0e, 0x09, 0x43, 0x17,
56 0xb8, 0x5a, 0xf0, 0x6e, 0xe2, 0x39, 0x5a, 0xfe },
57 { 0x6f, 0x95, 0x10, 0x7b, 0x21, 0x05, 0xce, 0x76,
58 0x3a, 0xa7, 0x88, 0x23, 0xa1, 0x49, 0x01, 0x44 },
59 { 0x17, 0xf3, 0x43, 0xa9, 0xb2, 0x1b, 0xf1, 0xeb,
60 0xee, 0xa5, 0x91, 0xa6, 0x39, 0x63, 0xf3, 0x17 },
61 { 0x0a, 0xe0, 0x30, 0x7a, 0x2c, 0xe2, 0x29, 0xb5,
62 0xa5, 0xae, 0x87, 0xa0, 0xac, 0x79, 0xcb, 0xc0 },
63 { 0x23, 0x0c, 0xce, 0xbd, 0xff, 0xde, 0xeb, 0x2f,
64 0x16, 0xae, 0xfa, 0x1c, 0x9d, 0x23, 0x23, 0x11 },
65 { 0x7b, 0x3f, 0xdd, 0x55, 0x2e, 0xe6, 0xe7, 0x77,
66 0x99, 0xc4, 0xb8, 0x9b, 0xe4, 0x1e, 0x48, 0xc9 },
67 { 0xb4, 0xb6, 0x7b, 0x40, 0x36, 0x91, 0xe8, 0x71,
68 0x55, 0xbf, 0xae, 0xa7, 0x39, 0xb8, 0x33, 0xca },
69 { 0xc3, 0xbd, 0xf6, 0xfc, 0x97, 0x36, 0x3c, 0xb6,
70 0x25, 0xf8, 0xe4, 0x7c, 0xb2, 0x59, 0xd9, 0x04 },
71 { 0xfd, 0x91, 0xe0, 0x28, 0x4c, 0x4c, 0x95, 0x41,
72 0x00, 0xdb, 0xb7, 0x7f, 0xf8, 0x66, 0xa0, 0xe3 },
73 { 0x76, 0x5b, 0x84, 0x57, 0x03, 0x1b, 0x25, 0x4f,
74 0xcd, 0x5b, 0xd4, 0x46, 0x29, 0x0d, 0xc3, 0xa2 },
75 { 0xf8, 0xee, 0xcc, 0x0a, 0x46, 0xb5, 0x55, 0xda,
76 0x52, 0x34, 0x47, 0x03, 0x3b, 0x71, 0x63, 0x58 },
77 { 0xdc, 0x75, 0x20, 0xb8, 0xee, 0x1f, 0x5f, 0xa7,
78 0xe8, 0x68, 0x42, 0xd8, 0xcc, 0x44, 0x2a, 0xa7 },
79 { 0x9e, 0x6e, 0xcf, 0x07, 0x25, 0x7b, 0x6d, 0xa1,
80 0x6c, 0xae, 0xa7, 0x9f, 0x29, 0x56, 0x2f, 0xd9 },
81 { 0xe4, 0xea, 0xb1, 0xfe, 0xe1, 0x3c, 0x8c, 0x8c,
82 0xa7, 0x64, 0x00, 0x4e, 0x2a, 0x7c, 0x38, 0x6a },
83 { 0x27, 0x94, 0x3a, 0x89, 0xa2, 0x13, 0x30, 0xcc,
84 0x5b, 0x38, 0x06, 0xf1, 0x27, 0xf9, 0x29, 0xa8 }
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, sizeof(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_le_init(&ctx, rtmpe8_keys[key_id]);
189 av_xtea_le_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_whitelist(&rt->stream, url, AVIO_FLAG_READ_WRITE,
268 &h->interrupt_callback, NULL,
269 h->protocol_whitelist, h->protocol_blacklist, h)) < 0) {
270 rtmpe_close(h);
271 return ret;
272 }
273
274 return 0;
275}
276
277static int rtmpe_read(URLContext *h, uint8_t *buf, int size)
278{
279 RTMPEContext *rt = h->priv_data;
280 int ret;
281
282 rt->stream->flags |= h->flags & AVIO_FLAG_NONBLOCK;
283 ret = ffurl_read(rt->stream, buf, size);
284 rt->stream->flags &= ~AVIO_FLAG_NONBLOCK;
285
286 if (ret < 0 && ret != AVERROR_EOF)
287 return ret;
288
289 if (rt->handshaked && ret > 0) {
290 /* decrypt data received by the server */
291 av_rc4_crypt(&rt->key_in, buf, buf, ret, NULL, 1);
292 }
293
294 return ret;
295}
296
297static int rtmpe_write(URLContext *h, const uint8_t *buf, int size)
298{
299 RTMPEContext *rt = h->priv_data;
300 int ret;
301
302 if (rt->handshaked) {
303 /* encrypt data to send to the server */
304 av_rc4_crypt(&rt->key_out, buf, buf, size, NULL, 1);
305 }
306
307 if ((ret = ffurl_write(rt->stream, buf, size)) < 0)
308 return ret;
309
310 return size;
311}
312
313#define OFFSET(x) offsetof(RTMPEContext, x)
314#define DEC AV_OPT_FLAG_DECODING_PARAM
315
316static const AVOption ffrtmpcrypt_options[] = {
317 {"ffrtmpcrypt_tunneling", "Use a HTTP tunneling connection (RTMPTE).", OFFSET(tunneling), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC},
318 { NULL },
319};
320
321static const AVClass ffrtmpcrypt_class = {
322 .class_name = "ffrtmpcrypt",
323 .item_name = av_default_item_name,
324 .option = ffrtmpcrypt_options,
325 .version = LIBAVUTIL_VERSION_INT,
326};
327
328const URLProtocol ff_ffrtmpcrypt_protocol = {
329 .name = "ffrtmpcrypt",
330 .url_open = rtmpe_open,
331 .url_read = rtmpe_read,
332 .url_write = rtmpe_write,
333 .url_close = rtmpe_close,
334 .priv_data_size = sizeof(RTMPEContext),
335 .flags = URL_PROTOCOL_FLAG_NETWORK,
336 .priv_data_class = &ffrtmpcrypt_class,
337};
338
generated by cgit at 2024-05-17 03:26:48 (GMT)