2 * RTMPE network protocol
3 * Copyright (c) 2008-2009 Andrej Stepanchuk
4 * Copyright (c) 2009-2010 Howard Chu
5 * Copyright (c) 2012 Samuel Pitoiset
7 * This file is part of FFmpeg.
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.
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.
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
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"
38 #include "rtmpcrypt.h"
41 /* protocol handler context */
42 typedef struct RTMPEContext
{
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)
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 }
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, },
122 int ff_rtmpe_gen_pub_key(URLContext
*h
, uint8_t *buf
)
124 RTMPEContext
*rt
= h
->priv_data
;
127 if (!(rt
->dh
= ff_dh_init(1024)))
128 return AVERROR(ENOMEM
);
130 offset
= ff_rtmp_calc_digest_pos(buf
, 768, 632, 8);
134 /* generate a Diffie-Hellmann public key */
135 if ((ret
= ff_dh_generate_public_key(rt
->dh
)) < 0)
138 /* write the public key into the handshake buffer */
139 if ((ret
= ff_dh_write_public_key(rt
->dh
, buf
+ offset
, 128)) < 0)
145 int ff_rtmpe_compute_secret_key(URLContext
*h
, const uint8_t *serverdata
,
146 const uint8_t *clientdata
, int type
)
148 RTMPEContext
*rt
= h
->priv_data
;
149 uint8_t secret_key
[128], digest
[32];
150 int server_pos
, client_pos
;
154 if ((server_pos
= ff_rtmp_calc_digest_pos(serverdata
, 1532, 632, 772)) < 0)
157 if ((server_pos
= ff_rtmp_calc_digest_pos(serverdata
, 768, 632, 8)) < 0)
161 if ((client_pos
= ff_rtmp_calc_digest_pos(clientdata
, 768, 632, 8)) < 0)
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)
170 if ((ret
= ff_rtmp_calc_digest(serverdata
+ server_pos
, 128, 0, secret_key
,
173 av_rc4_init(&rt
->key_out
, digest
, 16 * 8, 1);
176 if ((ret
= ff_rtmp_calc_digest(clientdata
+ client_pos
, 128, 0, secret_key
,
179 av_rc4_init(&rt
->key_in
, digest
, 16 * 8, 1);
184 static void rtmpe8_sig(const uint8_t *in
, uint8_t *out
, int key_id
)
188 av_xtea_init(&ctx
, rtmpe8_keys
[key_id
]);
189 av_xtea_crypt(&ctx
, out
, in
, 1, NULL
, 0);
192 static void rtmpe9_sig(const uint8_t *in
, uint8_t *out
, int key_id
)
194 struct AVBlowfish ctx
;
198 xr
= AV_RL32(in
+ 4);
200 av_blowfish_init(&ctx
, rtmpe9_keys
[key_id
], 24);
201 av_blowfish_crypt_ecb(&ctx
, &xl
, &xr
, 0);
204 AV_WL32(out
+ 4, xr
);
207 void ff_rtmpe_encrypt_sig(URLContext
*h
, uint8_t *sig
, const uint8_t *digest
,
212 for (i
= 0; i
< 32; i
+= 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);
223 int ff_rtmpe_update_keystream(URLContext
*h
)
225 RTMPEContext
*rt
= h
->priv_data
;
226 char buf
[RTMP_HANDSHAKE_PACKET_SIZE
];
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);
232 /* the next requests will be encrypted using RC4 keys */
238 static int rtmpe_close(URLContext
*h
)
240 RTMPEContext
*rt
= h
->priv_data
;
243 ffurl_close(rt
->stream
);
248 static int rtmpe_open(URLContext
*h
, const char *uri
, int flags
)
250 RTMPEContext
*rt
= h
->priv_data
;
251 char host
[256], url
[1024];
254 av_url_split(NULL
, 0, NULL
, 0, host
, sizeof(host
), &port
, NULL
, 0, uri
);
259 ff_url_join(url
, sizeof(url
), "ffrtmphttp", NULL
, host
, port
, NULL
);
263 ff_url_join(url
, sizeof(url
), "tcp", NULL
, host
, port
, NULL
);
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) {
276 static int rtmpe_read(URLContext
*h
, uint8_t *buf
, int size
)
278 RTMPEContext
*rt
= h
->priv_data
;
281 rt
->stream
->flags
|= h
->flags
& AVIO_FLAG_NONBLOCK
;
282 ret
= ffurl_read(rt
->stream
, buf
, size
);
283 rt
->stream
->flags
&= ~AVIO_FLAG_NONBLOCK
;
285 if (ret
< 0 && ret
!= AVERROR_EOF
)
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);
296 static int rtmpe_write(URLContext
*h
, const uint8_t *buf
, int size
)
298 RTMPEContext
*rt
= h
->priv_data
;
301 if (rt
->handshaked
) {
302 /* encrypt data to send to the server */
303 av_rc4_crypt(&rt
->key_out
, buf
, buf
, size
, NULL
, 1);
306 if ((ret
= ffurl_write(rt
->stream
, buf
, size
)) < 0)
312 #define OFFSET(x) offsetof(RTMPEContext, x)
313 #define DEC AV_OPT_FLAG_DECODING_PARAM
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
},
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
,
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
,