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rtmpdh.h
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1 /*
2  * RTMP Diffie-Hellmann utilities
3  * Copyright (c) 2012 Samuel Pitoiset
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 "avformat.h"
26 #include "config.h"
27 
28 #if CONFIG_GMP || CONFIG_GCRYPT
29 #if CONFIG_GMP
30 #include <gmp.h>
31 
32 typedef mpz_ptr FFBigNum;
33 #elif CONFIG_GCRYPT
34 #include <gcrypt.h>
35 
36 typedef gcry_mpi_t FFBigNum;
37 #endif
38 
39 typedef struct FF_DH {
40  FFBigNum p;
41  FFBigNum g;
42  FFBigNum pub_key;
43  FFBigNum priv_key;
44  long length;
45 } FF_DH;
46 
47 #elif CONFIG_OPENSSL
48 #include <openssl/bn.h>
49 #include <openssl/dh.h>
50 
51 typedef BIGNUM *FFBigNum;
52 typedef DH FF_DH;
53 #endif
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 */
const char * g
Definition: vf_curves.c:108
uint8_t
GLsizei GLsizei * length
Definition: opengl_enc.c:115
int ff_dh_compute_shared_secret_key(FF_DH *dh, const uint8_t *pub_key, int pub_key_len, uint8_t *secret_key, int secret_key_len)
Compute the shared secret key from the private FF_DH value and the other party's public value...
Definition: rtmpdh.c:321
void ff_dh_free(FF_DH *dh)
Free a Diffie-Hellmann context.
FF_DH * ff_dh_init(int key_len)
Initialize a Diffie-Hellmann context.
Definition: rtmpdh.c:252
Main libavformat public API header.
int ff_dh_write_public_key(FF_DH *dh, uint8_t *pub_key, int pub_key_len)
Write the public key into the given buffer.
Definition: rtmpdh.c:305
int ff_dh_generate_public_key(FF_DH *dh)
Generate a public key.
Definition: rtmpdh.c:279