forked from etc/pineapple-src
423 lines
13 KiB
C
Executable file
423 lines
13 KiB
C
Executable file
/*
|
|
* RTMP Diffie-Hellmann utilities
|
|
* Copyright (c) 2009 Andrej Stepanchuk
|
|
* Copyright (c) 2009-2010 Howard Chu
|
|
* Copyright (c) 2012 Samuel Pitoiset
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg 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.
|
|
*
|
|
* FFmpeg 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 FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* RTMP Diffie-Hellmann utilities
|
|
*/
|
|
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
#include "config.h"
|
|
|
|
#include "libavutil/attributes.h"
|
|
#include "libavutil/error.h"
|
|
#include "libavutil/mem.h"
|
|
#include "libavutil/random_seed.h"
|
|
|
|
#include "rtmpdh.h"
|
|
|
|
#if CONFIG_MBEDTLS
|
|
#include <mbedtls/ctr_drbg.h>
|
|
#include <mbedtls/entropy.h>
|
|
#endif
|
|
|
|
#define P1024 \
|
|
"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1" \
|
|
"29024E088A67CC74020BBEA63B139B22514A08798E3404DD" \
|
|
"EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245" \
|
|
"E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED" \
|
|
"EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381" \
|
|
"FFFFFFFFFFFFFFFF"
|
|
|
|
#define Q1024 \
|
|
"7FFFFFFFFFFFFFFFE487ED5110B4611A62633145C06E0E68" \
|
|
"948127044533E63A0105DF531D89CD9128A5043CC71A026E" \
|
|
"F7CA8CD9E69D218D98158536F92F8A1BA7F09AB6B6A8E122" \
|
|
"F242DABB312F3F637A262174D31BF6B585FFAE5B7A035BF6" \
|
|
"F71C35FDAD44CFD2D74F9208BE258FF324943328F67329C0" \
|
|
"FFFFFFFFFFFFFFFF"
|
|
|
|
#if CONFIG_GMP
|
|
#define bn_new(bn) \
|
|
do { \
|
|
bn = av_malloc(sizeof(*bn)); \
|
|
if (bn) \
|
|
mpz_init2(bn, 1); \
|
|
} while (0)
|
|
#define bn_free(bn) \
|
|
do { \
|
|
mpz_clear(bn); \
|
|
av_free(bn); \
|
|
} while (0)
|
|
#define bn_set_word(bn, w) mpz_set_ui(bn, w)
|
|
#define bn_cmp(a, b) mpz_cmp(a, b)
|
|
#define bn_copy(to, from) mpz_set(to, from)
|
|
#define bn_sub_word(bn, w) mpz_sub_ui(bn, bn, w)
|
|
#define bn_cmp_1(bn) mpz_cmp_ui(bn, 1)
|
|
#define bn_num_bytes(bn) (mpz_sizeinbase(bn, 2) + 7) / 8
|
|
#define bn_bn2bin(bn, buf, len) \
|
|
do { \
|
|
memset(buf, 0, len); \
|
|
if (bn_num_bytes(bn) <= len) \
|
|
mpz_export(buf, NULL, 1, 1, 0, 0, bn); \
|
|
} while (0)
|
|
#define bn_bin2bn(bn, buf, len) \
|
|
do { \
|
|
bn_new(bn); \
|
|
if (bn) \
|
|
mpz_import(bn, len, 1, 1, 0, 0, buf); \
|
|
} while (0)
|
|
#define bn_hex2bn(bn, buf, ret) \
|
|
do { \
|
|
bn_new(bn); \
|
|
if (bn) \
|
|
ret = (mpz_set_str(bn, buf, 16) == 0); \
|
|
else \
|
|
ret = 1; \
|
|
} while (0)
|
|
#define bn_random(bn, num_bits) \
|
|
do { \
|
|
int bits = num_bits; \
|
|
mpz_set_ui(bn, 0); \
|
|
for (bits = num_bits; bits > 0; bits -= 32) { \
|
|
mpz_mul_2exp(bn, bn, 32); \
|
|
mpz_add_ui(bn, bn, av_get_random_seed()); \
|
|
} \
|
|
mpz_fdiv_r_2exp(bn, bn, num_bits); \
|
|
} while (0)
|
|
static int bn_modexp(FFBigNum bn, FFBigNum y, FFBigNum q, FFBigNum p)
|
|
{
|
|
mpz_powm(bn, y, q, p);
|
|
return 0;
|
|
}
|
|
#elif CONFIG_GCRYPT
|
|
#define bn_new(bn) \
|
|
do { \
|
|
if (!gcry_control(GCRYCTL_INITIALIZATION_FINISHED_P)) { \
|
|
if (!gcry_check_version("1.5.4")) \
|
|
return AVERROR(EINVAL); \
|
|
gcry_control(GCRYCTL_DISABLE_SECMEM, 0); \
|
|
gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0); \
|
|
} \
|
|
bn = gcry_mpi_new(1); \
|
|
} while (0)
|
|
#define bn_free(bn) gcry_mpi_release(bn)
|
|
#define bn_set_word(bn, w) gcry_mpi_set_ui(bn, w)
|
|
#define bn_cmp(a, b) gcry_mpi_cmp(a, b)
|
|
#define bn_copy(to, from) gcry_mpi_set(to, from)
|
|
#define bn_sub_word(bn, w) gcry_mpi_sub_ui(bn, bn, w)
|
|
#define bn_cmp_1(bn) gcry_mpi_cmp_ui(bn, 1)
|
|
#define bn_num_bytes(bn) (gcry_mpi_get_nbits(bn) + 7) / 8
|
|
#define bn_bn2bin(bn, buf, len) gcry_mpi_print(GCRYMPI_FMT_USG, buf, len, NULL, bn)
|
|
#define bn_bin2bn(bn, buf, len) gcry_mpi_scan(&bn, GCRYMPI_FMT_USG, buf, len, NULL)
|
|
#define bn_hex2bn(bn, buf, ret) ret = (gcry_mpi_scan(&bn, GCRYMPI_FMT_HEX, buf, 0, 0) == 0)
|
|
#define bn_random(bn, num_bits) gcry_mpi_randomize(bn, num_bits, GCRY_WEAK_RANDOM)
|
|
static int bn_modexp(FFBigNum bn, FFBigNum y, FFBigNum q, FFBigNum p)
|
|
{
|
|
gcry_mpi_powm(bn, y, q, p);
|
|
return 0;
|
|
}
|
|
#elif CONFIG_OPENSSL
|
|
#define bn_new(bn) bn = BN_new()
|
|
#define bn_free(bn) BN_free(bn)
|
|
#define bn_set_word(bn, w) BN_set_word(bn, w)
|
|
#define bn_cmp(a, b) BN_cmp(a, b)
|
|
#define bn_copy(to, from) BN_copy(to, from)
|
|
#define bn_sub_word(bn, w) BN_sub_word(bn, w)
|
|
#define bn_cmp_1(bn) BN_cmp(bn, BN_value_one())
|
|
#define bn_num_bytes(bn) BN_num_bytes(bn)
|
|
#define bn_bn2bin(bn, buf, len) BN_bn2bin(bn, buf)
|
|
#define bn_bin2bn(bn, buf, len) bn = BN_bin2bn(buf, len, 0)
|
|
#define bn_hex2bn(bn, buf, ret) ret = BN_hex2bn(&bn, buf)
|
|
#define bn_random(bn, num_bits) BN_rand(bn, num_bits, 0, 0)
|
|
static int bn_modexp(FFBigNum bn, FFBigNum y, FFBigNum q, FFBigNum p)
|
|
{
|
|
BN_CTX *ctx = BN_CTX_new();
|
|
if (!ctx)
|
|
return AVERROR(ENOMEM);
|
|
if (!BN_mod_exp(bn, y, q, p, ctx)) {
|
|
BN_CTX_free(ctx);
|
|
return AVERROR(EINVAL);
|
|
}
|
|
BN_CTX_free(ctx);
|
|
return 0;
|
|
}
|
|
#elif CONFIG_MBEDTLS
|
|
#define bn_new(bn) \
|
|
do { \
|
|
bn = av_malloc(sizeof(*bn)); \
|
|
if (bn) \
|
|
mbedtls_mpi_init(bn); \
|
|
} while (0)
|
|
#define bn_free(bn) \
|
|
do { \
|
|
mbedtls_mpi_free(bn); \
|
|
av_free(bn); \
|
|
} while (0)
|
|
#define bn_set_word(bn, w) mbedtls_mpi_lset(bn, w)
|
|
#define bn_cmp(a, b) mbedtls_mpi_cmp_mpi(a, b)
|
|
#define bn_copy(to, from) mbedtls_mpi_copy(to, from)
|
|
#define bn_sub_word(bn, w) mbedtls_mpi_sub_int(bn, bn, w)
|
|
#define bn_cmp_1(bn) mbedtls_mpi_cmp_int(bn, 1)
|
|
#define bn_num_bytes(bn) (mbedtls_mpi_bitlen(bn) + 7) / 8
|
|
#define bn_bn2bin(bn, buf, len) mbedtls_mpi_write_binary(bn, buf, len)
|
|
#define bn_bin2bn(bn, buf, len) \
|
|
do { \
|
|
bn_new(bn); \
|
|
if (bn) \
|
|
mbedtls_mpi_read_binary(bn, buf, len); \
|
|
} while (0)
|
|
#define bn_hex2bn(bn, buf, ret) \
|
|
do { \
|
|
bn_new(bn); \
|
|
if (bn) \
|
|
ret = (mbedtls_mpi_read_string(bn, 16, buf) == 0); \
|
|
else \
|
|
ret = 1; \
|
|
} while (0)
|
|
#define bn_random(bn, num_bits) \
|
|
do { \
|
|
mbedtls_entropy_context entropy_ctx; \
|
|
mbedtls_ctr_drbg_context ctr_drbg_ctx; \
|
|
\
|
|
mbedtls_entropy_init(&entropy_ctx); \
|
|
mbedtls_ctr_drbg_init(&ctr_drbg_ctx); \
|
|
mbedtls_ctr_drbg_seed(&ctr_drbg_ctx, \
|
|
mbedtls_entropy_func, \
|
|
&entropy_ctx, \
|
|
NULL, 0); \
|
|
mbedtls_mpi_fill_random(bn, (num_bits + 7) / 8, mbedtls_ctr_drbg_random, &ctr_drbg_ctx); \
|
|
mbedtls_ctr_drbg_free(&ctr_drbg_ctx); \
|
|
mbedtls_entropy_free(&entropy_ctx); \
|
|
} while (0)
|
|
#define bn_modexp(bn, y, q, p) mbedtls_mpi_exp_mod(bn, y, q, p, 0)
|
|
|
|
#endif
|
|
|
|
#define MAX_BYTES 18000
|
|
|
|
#define dh_new() av_mallocz(sizeof(FF_DH))
|
|
|
|
static FFBigNum dh_generate_key(FF_DH *dh)
|
|
{
|
|
int num_bytes;
|
|
|
|
num_bytes = bn_num_bytes(dh->p) - 1;
|
|
if (num_bytes <= 0 || num_bytes > MAX_BYTES)
|
|
return NULL;
|
|
|
|
bn_new(dh->priv_key);
|
|
if (!dh->priv_key)
|
|
return NULL;
|
|
bn_random(dh->priv_key, 8 * num_bytes);
|
|
|
|
bn_new(dh->pub_key);
|
|
if (!dh->pub_key) {
|
|
bn_free(dh->priv_key);
|
|
return NULL;
|
|
}
|
|
|
|
if (bn_modexp(dh->pub_key, dh->g, dh->priv_key, dh->p) < 0)
|
|
return NULL;
|
|
|
|
return dh->pub_key;
|
|
}
|
|
|
|
static int dh_compute_key(FF_DH *dh, FFBigNum pub_key_bn,
|
|
uint32_t secret_key_len, uint8_t *secret_key)
|
|
{
|
|
FFBigNum k;
|
|
int ret;
|
|
|
|
bn_new(k);
|
|
if (!k)
|
|
return -1;
|
|
|
|
if ((ret = bn_modexp(k, pub_key_bn, dh->priv_key, dh->p)) < 0) {
|
|
bn_free(k);
|
|
return ret;
|
|
}
|
|
bn_bn2bin(k, secret_key, secret_key_len);
|
|
bn_free(k);
|
|
|
|
/* return the length of the shared secret key like DH_compute_key */
|
|
return secret_key_len;
|
|
}
|
|
|
|
void ff_dh_free(FF_DH *dh)
|
|
{
|
|
if (!dh)
|
|
return;
|
|
bn_free(dh->p);
|
|
bn_free(dh->g);
|
|
bn_free(dh->pub_key);
|
|
bn_free(dh->priv_key);
|
|
av_free(dh);
|
|
}
|
|
|
|
static int dh_is_valid_public_key(FFBigNum y, FFBigNum p, FFBigNum q)
|
|
{
|
|
FFBigNum bn = NULL;
|
|
int ret = AVERROR(EINVAL);
|
|
|
|
bn_new(bn);
|
|
if (!bn)
|
|
return AVERROR(ENOMEM);
|
|
|
|
/* y must lie in [2, p - 1] */
|
|
bn_set_word(bn, 1);
|
|
if (!bn_cmp(y, bn))
|
|
goto fail;
|
|
|
|
/* bn = p - 2 */
|
|
bn_copy(bn, p);
|
|
bn_sub_word(bn, 1);
|
|
if (!bn_cmp(y, bn))
|
|
goto fail;
|
|
|
|
/* Verify with Sophie-Germain prime
|
|
*
|
|
* This is a nice test to make sure the public key position is calculated
|
|
* correctly. This test will fail in about 50% of the cases if applied to
|
|
* random data.
|
|
*/
|
|
/* y must fulfill y^q mod p = 1 */
|
|
if ((ret = bn_modexp(bn, y, q, p)) < 0)
|
|
goto fail;
|
|
|
|
ret = AVERROR(EINVAL);
|
|
if (bn_cmp_1(bn))
|
|
goto fail;
|
|
|
|
ret = 0;
|
|
fail:
|
|
bn_free(bn);
|
|
|
|
return ret;
|
|
}
|
|
|
|
av_cold FF_DH *ff_dh_init(int key_len)
|
|
{
|
|
FF_DH *dh;
|
|
int ret;
|
|
|
|
if (!(dh = dh_new()))
|
|
return NULL;
|
|
|
|
bn_new(dh->g);
|
|
if (!dh->g)
|
|
goto fail;
|
|
|
|
bn_hex2bn(dh->p, P1024, ret);
|
|
if (!ret)
|
|
goto fail;
|
|
|
|
bn_set_word(dh->g, 2);
|
|
dh->length = key_len;
|
|
|
|
return dh;
|
|
|
|
fail:
|
|
ff_dh_free(dh);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int ff_dh_generate_public_key(FF_DH *dh)
|
|
{
|
|
int ret = 0;
|
|
|
|
while (!ret) {
|
|
FFBigNum q1 = NULL;
|
|
|
|
if (!dh_generate_key(dh))
|
|
return AVERROR(EINVAL);
|
|
|
|
bn_hex2bn(q1, Q1024, ret);
|
|
if (!ret)
|
|
return AVERROR(ENOMEM);
|
|
|
|
ret = dh_is_valid_public_key(dh->pub_key, dh->p, q1);
|
|
bn_free(q1);
|
|
|
|
if (!ret) {
|
|
/* the public key is valid */
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int ff_dh_write_public_key(FF_DH *dh, uint8_t *pub_key, int pub_key_len)
|
|
{
|
|
int len;
|
|
|
|
/* compute the length of the public key */
|
|
len = bn_num_bytes(dh->pub_key);
|
|
if (len <= 0 || len > pub_key_len)
|
|
return AVERROR(EINVAL);
|
|
|
|
/* convert the public key value into big-endian form */
|
|
memset(pub_key, 0, pub_key_len);
|
|
bn_bn2bin(dh->pub_key, pub_key + pub_key_len - len, len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
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)
|
|
{
|
|
FFBigNum q1 = NULL, pub_key_bn = NULL;
|
|
int ret;
|
|
|
|
/* convert the big-endian form of the public key into a bignum */
|
|
bn_bin2bn(pub_key_bn, pub_key, pub_key_len);
|
|
if (!pub_key_bn)
|
|
return AVERROR(ENOMEM);
|
|
|
|
/* convert the string containing a hexadecimal number into a bignum */
|
|
bn_hex2bn(q1, Q1024, ret);
|
|
if (!ret) {
|
|
ret = AVERROR(ENOMEM);
|
|
goto fail;
|
|
}
|
|
|
|
/* when the public key is valid we have to compute the shared secret key */
|
|
if ((ret = dh_is_valid_public_key(pub_key_bn, dh->p, q1)) < 0) {
|
|
goto fail;
|
|
} else if ((ret = dh_compute_key(dh, pub_key_bn, secret_key_len,
|
|
secret_key)) < 0) {
|
|
ret = AVERROR(EINVAL);
|
|
goto fail;
|
|
}
|
|
|
|
fail:
|
|
bn_free(pub_key_bn);
|
|
bn_free(q1);
|
|
|
|
return ret;
|
|
}
|