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486 lines
16 KiB
486 lines
16 KiB
/* |
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* RTMP Diffie-Hellmann utilities |
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* Copyright (c) 2009 Andrej Stepanchuk |
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* Copyright (c) 2009-2010 Howard Chu |
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* Copyright (c) 2012 Samuel Pitoiset |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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|
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/** |
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* @file |
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* RTMP Diffie-Hellmann utilities |
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*/ |
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#include "config.h" |
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#include "rtmpdh.h" |
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#include "libavutil/random_seed.h" |
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#define P1024 \ |
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"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1" \ |
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"29024E088A67CC74020BBEA63B139B22514A08798E3404DD" \ |
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"EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245" \ |
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"E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED" \ |
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"EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381" \ |
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"FFFFFFFFFFFFFFFF" |
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|
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#define Q1024 \ |
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"7FFFFFFFFFFFFFFFE487ED5110B4611A62633145C06E0E68" \ |
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"948127044533E63A0105DF531D89CD9128A5043CC71A026E" \ |
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"F7CA8CD9E69D218D98158536F92F8A1BA7F09AB6B6A8E122" \ |
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"F242DABB312F3F637A262174D31BF6B585FFAE5B7A035BF6" \ |
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"F71C35FDAD44CFD2D74F9208BE258FF324943328F67329C0" \ |
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"FFFFFFFFFFFFFFFF" |
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|
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#if CONFIG_NETTLE || CONFIG_GCRYPT |
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#if CONFIG_NETTLE |
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#define bn_new(bn) \ |
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do { \ |
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bn = av_malloc(sizeof(*bn)); \ |
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if (bn) \ |
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mpz_init2(bn, 1); \ |
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} while (0) |
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#define bn_free(bn) \ |
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do { \ |
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mpz_clear(bn); \ |
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av_free(bn); \ |
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} while (0) |
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#define bn_set_word(bn, w) mpz_set_ui(bn, w) |
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#define bn_cmp(a, b) mpz_cmp(a, b) |
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#define bn_copy(to, from) mpz_set(to, from) |
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#define bn_sub_word(bn, w) mpz_sub_ui(bn, bn, w) |
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#define bn_cmp_1(bn) mpz_cmp_ui(bn, 1) |
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#define bn_num_bytes(bn) (mpz_sizeinbase(bn, 2) + 7) / 8 |
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#define bn_bn2bin(bn, buf, len) nettle_mpz_get_str_256(len, buf, bn) |
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#define bn_bin2bn(bn, buf, len) \ |
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do { \ |
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bn_new(bn); \ |
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if (bn) \ |
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nettle_mpz_set_str_256_u(bn, len, buf); \ |
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} while (0) |
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#define bn_hex2bn(bn, buf, ret) \ |
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do { \ |
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bn_new(bn); \ |
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if (bn) \ |
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ret = (mpz_set_str(bn, buf, 16) == 0); \ |
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else \ |
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ret = 1; \ |
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} while (0) |
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#define bn_modexp(bn, y, q, p) mpz_powm(bn, y, q, p) |
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#define bn_random(bn, num_bits) \ |
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do { \ |
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gmp_randstate_t rs; \ |
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gmp_randinit_mt(rs); \ |
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gmp_randseed_ui(rs, av_get_random_seed()); \ |
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mpz_urandomb(bn, rs, num_bits); \ |
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gmp_randclear(rs); \ |
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} while (0) |
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#elif CONFIG_GCRYPT |
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#define bn_new(bn) bn = gcry_mpi_new(1) |
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#define bn_free(bn) gcry_mpi_release(bn) |
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#define bn_set_word(bn, w) gcry_mpi_set_ui(bn, w) |
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#define bn_cmp(a, b) gcry_mpi_cmp(a, b) |
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#define bn_copy(to, from) gcry_mpi_set(to, from) |
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#define bn_sub_word(bn, w) gcry_mpi_sub_ui(bn, bn, w) |
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#define bn_cmp_1(bn) gcry_mpi_cmp_ui(bn, 1) |
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#define bn_num_bytes(bn) (gcry_mpi_get_nbits(bn) + 7) / 8 |
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#define bn_bn2bin(bn, buf, len) gcry_mpi_print(GCRYMPI_FMT_USG, buf, len, NULL, bn) |
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#define bn_bin2bn(bn, buf, len) gcry_mpi_scan(&bn, GCRYMPI_FMT_USG, buf, len, NULL) |
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#define bn_hex2bn(bn, buf, ret) ret = (gcry_mpi_scan(&bn, GCRYMPI_FMT_HEX, buf, 0, 0) == 0) |
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#define bn_modexp(bn, y, q, p) gcry_mpi_powm(bn, y, q, p) |
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#define bn_random(bn, num_bits) gcry_mpi_randomize(bn, num_bits, GCRY_WEAK_RANDOM) |
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#endif |
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#define MAX_BYTES 18000 |
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#define dh_new() av_malloc(sizeof(FF_DH)) |
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static FFBigNum dh_generate_key(FF_DH *dh) |
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{ |
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int num_bytes; |
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num_bytes = bn_num_bytes(dh->p) - 1; |
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if (num_bytes <= 0 || num_bytes > MAX_BYTES) |
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return NULL; |
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bn_new(dh->priv_key); |
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if (!dh->priv_key) |
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return NULL; |
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bn_random(dh->priv_key, 8 * num_bytes); |
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bn_new(dh->pub_key); |
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if (!dh->pub_key) { |
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bn_free(dh->priv_key); |
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return NULL; |
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} |
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bn_modexp(dh->pub_key, dh->g, dh->priv_key, dh->p); |
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return dh->pub_key; |
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} |
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static int dh_compute_key(FF_DH *dh, FFBigNum pub_key_bn, |
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uint32_t secret_key_len, uint8_t *secret_key) |
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{ |
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FFBigNum k; |
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bn_new(k); |
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if (!k) |
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return -1; |
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bn_modexp(k, pub_key_bn, dh->priv_key, dh->p); |
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bn_bn2bin(k, secret_key, secret_key_len); |
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bn_free(k); |
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/* return the length of the shared secret key like DH_compute_key */ |
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return secret_key_len; |
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} |
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void ff_dh_free(FF_DH *dh) |
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{ |
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if (!dh) |
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return; |
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bn_free(dh->p); |
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bn_free(dh->g); |
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bn_free(dh->pub_key); |
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bn_free(dh->priv_key); |
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av_free(dh); |
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} |
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#elif CONFIG_OPENSSL |
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#define bn_new(bn) bn = BN_new() |
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#define bn_free(bn) BN_free(bn) |
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#define bn_set_word(bn, w) BN_set_word(bn, w) |
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#define bn_cmp(a, b) BN_cmp(a, b) |
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#define bn_copy(to, from) BN_copy(to, from) |
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#define bn_sub_word(bn, w) BN_sub_word(bn, w) |
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#define bn_cmp_1(bn) BN_cmp(bn, BN_value_one()) |
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#define bn_num_bytes(bn) BN_num_bytes(bn) |
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#define bn_bn2bin(bn, buf, len) BN_bn2bin(bn, buf) |
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#define bn_bin2bn(bn, buf, len) bn = BN_bin2bn(buf, len, 0) |
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#define bn_hex2bn(bn, buf, ret) ret = BN_hex2bn(&bn, buf) |
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#define bn_modexp(bn, y, q, p) \ |
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do { \ |
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BN_CTX *ctx = BN_CTX_new(); \ |
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if (!ctx) \ |
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return AVERROR(ENOMEM); \ |
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if (!BN_mod_exp(bn, y, q, p, ctx)) { \ |
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BN_CTX_free(ctx); \ |
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return AVERROR(EINVAL); \ |
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} \ |
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BN_CTX_free(ctx); \ |
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} while (0) |
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#define dh_new() DH_new() |
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#define dh_generate_key(dh) DH_generate_key(dh) |
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static int dh_compute_key(FF_DH *dh, FFBigNum pub_key_bn, |
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uint32_t secret_key_len, uint8_t *secret_key) |
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{ |
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if (secret_key_len < DH_size(dh)) |
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return AVERROR(EINVAL); |
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return DH_compute_key(secret_key, pub_key_bn, dh); |
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} |
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void ff_dh_free(FF_DH *dh) |
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{ |
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if (!dh) |
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return; |
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DH_free(dh); |
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} |
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#endif |
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static int dh_is_valid_public_key(FFBigNum y, FFBigNum p, FFBigNum q) |
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{ |
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FFBigNum bn = NULL; |
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int ret = AVERROR(EINVAL); |
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bn_new(bn); |
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if (!bn) |
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return AVERROR(ENOMEM); |
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/* y must lie in [2, p - 1] */ |
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bn_set_word(bn, 1); |
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if (!bn_cmp(y, bn)) |
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goto fail; |
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/* bn = p - 2 */ |
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bn_copy(bn, p); |
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bn_sub_word(bn, 1); |
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if (!bn_cmp(y, bn)) |
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goto fail; |
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|
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/* Verify with Sophie-Germain prime |
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* |
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* This is a nice test to make sure the public key position is calculated |
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* correctly. This test will fail in about 50% of the cases if applied to |
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* random data. |
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*/ |
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/* y must fulfill y^q mod p = 1 */ |
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bn_modexp(bn, y, q, p); |
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if (bn_cmp_1(bn)) |
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goto fail; |
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ret = 0; |
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fail: |
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bn_free(bn); |
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return ret; |
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} |
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av_cold FF_DH *ff_dh_init(int key_len) |
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{ |
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FF_DH *dh; |
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int ret; |
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if (!(dh = dh_new())) |
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return NULL; |
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bn_new(dh->g); |
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if (!dh->g) |
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goto fail; |
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bn_hex2bn(dh->p, P1024, ret); |
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if (!ret) |
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goto fail; |
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bn_set_word(dh->g, 2); |
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dh->length = key_len; |
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return dh; |
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fail: |
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ff_dh_free(dh); |
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return NULL; |
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} |
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int ff_dh_generate_public_key(FF_DH *dh) |
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{ |
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int ret = 0; |
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while (!ret) { |
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FFBigNum q1 = NULL; |
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if (!dh_generate_key(dh)) |
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return AVERROR(EINVAL); |
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bn_hex2bn(q1, Q1024, ret); |
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if (!ret) |
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return AVERROR(ENOMEM); |
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ret = dh_is_valid_public_key(dh->pub_key, dh->p, q1); |
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bn_free(q1); |
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if (!ret) { |
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/* the public key is valid */ |
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break; |
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} |
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} |
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return ret; |
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} |
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int ff_dh_write_public_key(FF_DH *dh, uint8_t *pub_key, int pub_key_len) |
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{ |
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int len; |
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/* compute the length of the public key */ |
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len = bn_num_bytes(dh->pub_key); |
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if (len <= 0 || len > pub_key_len) |
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return AVERROR(EINVAL); |
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/* convert the public key value into big-endian form */ |
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memset(pub_key, 0, pub_key_len); |
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bn_bn2bin(dh->pub_key, pub_key + pub_key_len - len, len); |
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return 0; |
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} |
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int ff_dh_compute_shared_secret_key(FF_DH *dh, const uint8_t *pub_key, |
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int pub_key_len, uint8_t *secret_key, |
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int secret_key_len) |
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{ |
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FFBigNum q1 = NULL, pub_key_bn = NULL; |
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int ret; |
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/* convert the big-endian form of the public key into a bignum */ |
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bn_bin2bn(pub_key_bn, pub_key, pub_key_len); |
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if (!pub_key_bn) |
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return AVERROR(ENOMEM); |
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/* convert the string containing a hexadecimal number into a bignum */ |
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bn_hex2bn(q1, Q1024, ret); |
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if (!ret) { |
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ret = AVERROR(ENOMEM); |
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goto fail; |
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} |
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/* when the public key is valid we have to compute the shared secret key */ |
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if ((ret = dh_is_valid_public_key(pub_key_bn, dh->p, q1)) < 0) { |
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goto fail; |
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} else if ((ret = dh_compute_key(dh, pub_key_bn, secret_key_len, |
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secret_key)) < 0) { |
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ret = AVERROR(EINVAL); |
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goto fail; |
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} |
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fail: |
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bn_free(pub_key_bn); |
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bn_free(q1); |
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return ret; |
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} |
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#ifdef TEST |
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static int test_random_shared_secret(void) |
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{ |
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FF_DH *peer1 = NULL, *peer2 = NULL; |
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int ret; |
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uint8_t pubkey1[128], pubkey2[128]; |
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uint8_t sharedkey1[128], sharedkey2[128]; |
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peer1 = ff_dh_init(1024); |
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peer2 = ff_dh_init(1024); |
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if (!peer1 || !peer2) { |
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ret = AVERROR(ENOMEM); |
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goto fail; |
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} |
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if ((ret = ff_dh_generate_public_key(peer1)) < 0) |
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goto fail; |
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if ((ret = ff_dh_generate_public_key(peer2)) < 0) |
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goto fail; |
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if ((ret = ff_dh_write_public_key(peer1, pubkey1, sizeof(pubkey1))) < 0) |
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goto fail; |
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if ((ret = ff_dh_write_public_key(peer2, pubkey2, sizeof(pubkey2))) < 0) |
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goto fail; |
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if ((ret = ff_dh_compute_shared_secret_key(peer1, pubkey2, sizeof(pubkey2), |
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sharedkey1, sizeof(sharedkey1))) < 0) |
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goto fail; |
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if ((ret = ff_dh_compute_shared_secret_key(peer2, pubkey1, sizeof(pubkey1), |
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sharedkey2, sizeof(sharedkey2))) < 0) |
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goto fail; |
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if (memcmp(sharedkey1, sharedkey2, sizeof(sharedkey1))) { |
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printf("Mismatched generated shared key\n"); |
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ret = AVERROR_INVALIDDATA; |
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} else { |
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printf("Generated shared key ok\n"); |
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} |
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fail: |
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ff_dh_free(peer1); |
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ff_dh_free(peer2); |
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return ret; |
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} |
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static const char *private_key = |
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"976C18FCADC255B456564F74F3EEDA59D28AF6B744D743F2357BFD2404797EF896EF1A" |
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"7C1CBEAAA3AB60AF3192D189CFF3F991C9CBBFD78119FCA2181384B94011943B6D6F28" |
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"9E1B708E2D1A0C7771169293F03DA27E561F15F16F0AC9BC858C77A80FA98FD088A232" |
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"19D08BE6F165DE0B02034B18705829FAD0ACB26A5B75EF"; |
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static const char *public_key = |
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"F272ECF8362257C5D2C3CC2229CF9C0A03225BC109B1DBC76A68C394F256ACA3EF5F64" |
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"FC270C26382BF315C19E97A76104A716FC998A651E8610A3AE6CF65D8FAE5D3F32EEA0" |
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"0B32CB9609B494116A825D7142D17B88E3D20EDD98743DE29CF37A23A9F6A58B960591" |
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"3157D5965FCB46DDA73A1F08DD897BAE88DFE6FC937CBA"; |
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static const uint8_t public_key_bin[] = { |
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0xf2, 0x72, 0xec, 0xf8, 0x36, 0x22, 0x57, 0xc5, 0xd2, 0xc3, 0xcc, 0x22, |
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0x29, 0xcf, 0x9c, 0x0a, 0x03, 0x22, 0x5b, 0xc1, 0x09, 0xb1, 0xdb, 0xc7, |
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0x6a, 0x68, 0xc3, 0x94, 0xf2, 0x56, 0xac, 0xa3, 0xef, 0x5f, 0x64, 0xfc, |
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0x27, 0x0c, 0x26, 0x38, 0x2b, 0xf3, 0x15, 0xc1, 0x9e, 0x97, 0xa7, 0x61, |
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0x04, 0xa7, 0x16, 0xfc, 0x99, 0x8a, 0x65, 0x1e, 0x86, 0x10, 0xa3, 0xae, |
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0x6c, 0xf6, 0x5d, 0x8f, 0xae, 0x5d, 0x3f, 0x32, 0xee, 0xa0, 0x0b, 0x32, |
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0xcb, 0x96, 0x09, 0xb4, 0x94, 0x11, 0x6a, 0x82, 0x5d, 0x71, 0x42, 0xd1, |
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0x7b, 0x88, 0xe3, 0xd2, 0x0e, 0xdd, 0x98, 0x74, 0x3d, 0xe2, 0x9c, 0xf3, |
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0x7a, 0x23, 0xa9, 0xf6, 0xa5, 0x8b, 0x96, 0x05, 0x91, 0x31, 0x57, 0xd5, |
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0x96, 0x5f, 0xcb, 0x46, 0xdd, 0xa7, 0x3a, 0x1f, 0x08, 0xdd, 0x89, 0x7b, |
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0xae, 0x88, 0xdf, 0xe6, 0xfc, 0x93, 0x7c, 0xba |
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}; |
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static const uint8_t peer_public_key[] = { |
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0x58, 0x66, 0x05, 0x49, 0x94, 0x23, 0x2b, 0x66, 0x52, 0x13, 0xff, 0x46, |
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0xf2, 0xb3, 0x79, 0xa9, 0xee, 0xae, 0x1a, 0x13, 0xf0, 0x71, 0x52, 0xfb, |
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0x93, 0x4e, 0xee, 0x97, 0x05, 0x73, 0x50, 0x7d, 0xaf, 0x02, 0x07, 0x72, |
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0xac, 0xdc, 0xa3, 0x95, 0x78, 0xee, 0x9a, 0x19, 0x71, 0x7e, 0x99, 0x9f, |
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0x2a, 0xd4, 0xb3, 0xe2, 0x0c, 0x1d, 0x1a, 0x78, 0x4c, 0xde, 0xf1, 0xad, |
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0xb4, 0x60, 0xa8, 0x51, 0xac, 0x71, 0xec, 0x86, 0x70, 0xa2, 0x63, 0x36, |
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0x92, 0x7c, 0xe3, 0x87, 0xee, 0xe4, 0xf1, 0x62, 0x24, 0x74, 0xb4, 0x04, |
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0xfa, 0x5c, 0xdf, 0xba, 0xfa, 0xa3, 0xc2, 0xbb, 0x62, 0x27, 0xd0, 0xf4, |
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0xe4, 0x43, 0xda, 0x8a, 0x88, 0x69, 0x60, 0xe2, 0xdb, 0x75, 0x2a, 0x98, |
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0x9d, 0xb5, 0x50, 0xe3, 0x99, 0xda, 0xe0, 0xa6, 0x14, 0xc9, 0x80, 0x12, |
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0xf9, 0x3c, 0xac, 0x06, 0x02, 0x7a, 0xde, 0x74 |
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}; |
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static const uint8_t shared_secret[] = { |
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0xb2, 0xeb, 0xcb, 0x71, 0xf3, 0x61, 0xfb, 0x5b, 0x4e, 0x5c, 0x4c, 0xcf, |
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0x5c, 0x08, 0x5f, 0x96, 0x26, 0x77, 0x1d, 0x31, 0xf1, 0xe1, 0xf7, 0x4b, |
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0x92, 0xac, 0x82, 0x2a, 0x88, 0xc7, 0x83, 0xe1, 0xc7, 0xf3, 0xd3, 0x1a, |
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0x7d, 0xc8, 0x31, 0xe3, 0x97, 0xe4, 0xec, 0x31, 0x0e, 0x8f, 0x73, 0x1a, |
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0xe4, 0xf6, 0xd8, 0xc8, 0x94, 0xff, 0xa0, 0x03, 0x84, 0x03, 0x0f, 0xa5, |
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0x30, 0x5d, 0x67, 0xe0, 0x7a, 0x3b, 0x5f, 0xed, 0x4c, 0xf5, 0xbc, 0x18, |
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0xea, 0xd4, 0x77, 0xa9, 0x07, 0xb3, 0x54, 0x0b, 0x02, 0xd9, 0xc6, 0xb8, |
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0x66, 0x5e, 0xec, 0xa4, 0xcd, 0x47, 0xed, 0xc9, 0x38, 0xc6, 0x91, 0x08, |
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0xf3, 0x85, 0x9b, 0x69, 0x16, 0x78, 0x0d, 0xb7, 0x74, 0x51, 0xaa, 0x5b, |
|
0x4d, 0x74, 0xe4, 0x29, 0x2e, 0x9e, 0x8e, 0xf7, 0xe5, 0x42, 0x83, 0xb0, |
|
0x65, 0xb0, 0xce, 0xc6, 0xb2, 0x8f, 0x5b, 0xb0 |
|
}; |
|
|
|
static int test_ref_data(void) |
|
{ |
|
FF_DH *dh; |
|
int ret = AVERROR(ENOMEM); |
|
uint8_t pubkey_test[128]; |
|
uint8_t sharedkey_test[128]; |
|
|
|
dh = ff_dh_init(1024); |
|
if (!dh) |
|
goto fail; |
|
bn_hex2bn(dh->priv_key, private_key, ret); |
|
if (!ret) |
|
goto fail; |
|
bn_hex2bn(dh->pub_key, public_key, ret); |
|
if (!ret) |
|
goto fail; |
|
if ((ret = ff_dh_write_public_key(dh, pubkey_test, sizeof(pubkey_test))) < 0) |
|
goto fail; |
|
if (memcmp(pubkey_test, public_key_bin, sizeof(pubkey_test))) { |
|
printf("Mismatched generated public key\n"); |
|
ret = AVERROR_INVALIDDATA; |
|
goto fail; |
|
} else { |
|
printf("Generated public key ok\n"); |
|
} |
|
if ((ret = ff_dh_compute_shared_secret_key(dh, peer_public_key, sizeof(peer_public_key), |
|
sharedkey_test, sizeof(sharedkey_test))) < 0) |
|
goto fail; |
|
if (memcmp(shared_secret, sharedkey_test, sizeof(sharedkey_test))) { |
|
printf("Mismatched generated shared key\n"); |
|
ret = AVERROR_INVALIDDATA; |
|
} else { |
|
printf("Generated shared key ok\n"); |
|
} |
|
fail: |
|
ff_dh_free(dh); |
|
return ret; |
|
} |
|
|
|
int main(void) |
|
{ |
|
if (test_random_shared_secret() < 0) |
|
return 1; |
|
if (test_ref_data() < 0) |
|
return 1; |
|
return 0; |
|
} |
|
#endif
|
|
|