libavformat: add mbedTLS based TLS
[libav.git] / libavformat / rtmpdh.h
1 /*
2 * RTMP Diffie-Hellmann utilities
3 * Copyright (c) 2012 Samuel Pitoiset
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #ifndef AVFORMAT_RTMPDH_H
23 #define AVFORMAT_RTMPDH_H
24
25 #include <stdint.h>
26
27 #include "config.h"
28
29 #if CONFIG_GMP
30 #include <gmp.h>
31
32 typedef mpz_ptr FFBigNum;
33 #elif CONFIG_OPENSSL
34 #include <openssl/bn.h>
35 #include <openssl/dh.h>
36
37 typedef BIGNUM *FFBigNum;
38 #elif CONFIG_MBEDTLS
39 #include <mbedtls/bignum.h>
40 #include <mbedtls/ctr_drbg.h>
41 #include <mbedtls/entropy.h>
42
43 typedef mbedtls_mpi *FFBigNum;
44 #endif
45
46 typedef struct FF_DH {
47 FFBigNum p;
48 FFBigNum g;
49 FFBigNum pub_key;
50 FFBigNum priv_key;
51 long length;
52 } FF_DH;
53
54
55 /**
56 * Initialize a Diffie-Hellmann context.
57 *
58 * @param key_len length of the key
59 * @return a new Diffie-Hellmann context on success, NULL otherwise
60 */
61 FF_DH *ff_dh_init(int key_len);
62
63 /**
64 * Free a Diffie-Hellmann context.
65 *
66 * @param dh a Diffie-Hellmann context to free
67 */
68 void ff_dh_free(FF_DH *dh);
69
70 /**
71 * Generate a public key.
72 *
73 * @param dh a Diffie-Hellmann context
74 * @return zero on success, negative value otherwise
75 */
76 int ff_dh_generate_public_key(FF_DH *dh);
77
78 /**
79 * Write the public key into the given buffer.
80 *
81 * @param dh a Diffie-Hellmann context, containing the public key to write
82 * @param pub_key the buffer where the public key is written
83 * @param pub_key_len the length of the buffer
84 * @return zero on success, negative value otherwise
85 */
86 int ff_dh_write_public_key(FF_DH *dh, uint8_t *pub_key, int pub_key_len);
87
88 /**
89 * Compute the shared secret key from the private FF_DH value and the
90 * other party's public value.
91 *
92 * @param dh a Diffie-Hellmann context, containing the private key
93 * @param pub_key the buffer containing the public key
94 * @param pub_key_len the length of the public key buffer
95 * @param secret_key the buffer where the secret key is written
96 * @param secret_key_len the length of the secret key buffer
97 * @return length of the shared secret key on success, negative value otherwise
98 */
99 int ff_dh_compute_shared_secret_key(FF_DH *dh, const uint8_t *pub_key,
100 int pub_key_len, uint8_t *secret_key,
101 int secret_key_len);
102
103 #endif /* AVFORMAT_RTMPDH_H */