34 "FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1" \ 35 "29024E088A67CC74020BBEA63B139B22514A08798E3404DD" \ 36 "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245" \ 37 "E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED" \ 38 "EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381" \ 42 "7FFFFFFFFFFFFFFFE487ED5110B4611A62633145C06E0E68" \ 43 "948127044533E63A0105DF531D89CD9128A5043CC71A026E" \ 44 "F7CA8CD9E69D218D98158536F92F8A1BA7F09AB6B6A8E122" \ 45 "F242DABB312F3F637A262174D31BF6B585FFAE5B7A035BF6" \ 46 "F71C35FDAD44CFD2D74F9208BE258FF324943328F67329C0" \ 49 #if CONFIG_NETTLE || CONFIG_GCRYPT 53 bn = av_malloc(sizeof(*bn)); \ 62 #define bn_set_word(bn, w) mpz_set_ui(bn, w) 63 #define bn_cmp(a, b) mpz_cmp(a, b) 64 #define bn_copy(to, from) mpz_set(to, from) 65 #define bn_sub_word(bn, w) mpz_sub_ui(bn, bn, w) 66 #define bn_cmp_1(bn) mpz_cmp_ui(bn, 1) 67 #define bn_num_bytes(bn) (mpz_sizeinbase(bn, 2) + 7) / 8 68 #define bn_bn2bin(bn, buf, len) nettle_mpz_get_str_256(len, buf, bn) 69 #define bn_bin2bn(bn, buf, len) \ 73 nettle_mpz_set_str_256_u(bn, len, buf); \ 75 #define bn_hex2bn(bn, buf, ret) \ 79 ret = (mpz_set_str(bn, buf, 16) == 0); \ 81 #define bn_modexp(bn, y, q, p) mpz_powm(bn, y, q, p) 82 #define bn_random(bn, num_bytes) \ 85 gmp_randinit_mt(rs); \ 86 gmp_randseed_ui(rs, av_get_random_seed()); \ 87 mpz_urandomb(bn, rs, num_bytes); \ 91 #define bn_new(bn) bn = gcry_mpi_new(1) 92 #define bn_free(bn) gcry_mpi_release(bn) 93 #define bn_set_word(bn, w) gcry_mpi_set_ui(bn, w) 94 #define bn_cmp(a, b) gcry_mpi_cmp(a, b) 95 #define bn_copy(to, from) gcry_mpi_set(to, from) 96 #define bn_sub_word(bn, w) gcry_mpi_sub_ui(bn, bn, w) 97 #define bn_cmp_1(bn) gcry_mpi_cmp_ui(bn, 1) 98 #define bn_num_bytes(bn) (gcry_mpi_get_nbits(bn) + 7) / 8 99 #define bn_bn2bin(bn, buf, len) gcry_mpi_print(GCRYMPI_FMT_USG, buf, len, NULL, bn) 100 #define bn_bin2bn(bn, buf, len) gcry_mpi_scan(&bn, GCRYMPI_FMT_USG, buf, len, NULL) 101 #define bn_hex2bn(bn, buf, ret) ret = (gcry_mpi_scan(&bn, GCRYMPI_FMT_HEX, buf, 0, 0) == 0) 102 #define bn_modexp(bn, y, q, p) gcry_mpi_powm(bn, y, q, p) 103 #define bn_random(bn, num_bytes) gcry_mpi_randomize(bn, num_bytes, GCRY_WEAK_RANDOM) 106 #define MAX_BYTES 18000 108 #define dh_new() av_malloc(sizeof(FF_DH)) 110 static FFBigNum dh_generate_key(FF_DH *dh)
114 num_bytes = bn_num_bytes(dh->p) - 1;
115 if (num_bytes <= 0 || num_bytes > MAX_BYTES)
118 bn_new(dh->priv_key);
121 bn_random(dh->priv_key, num_bytes);
125 bn_free(dh->priv_key);
129 bn_modexp(dh->pub_key, dh->g, dh->priv_key, dh->p);
134 static int dh_compute_key(FF_DH *dh, FFBigNum pub_key_bn,
135 uint32_t pub_key_len,
uint8_t *secret_key)
140 num_bytes = bn_num_bytes(dh->p);
141 if (num_bytes <= 0 || num_bytes > MAX_BYTES)
148 bn_modexp(k, pub_key_bn, dh->priv_key, dh->p);
149 bn_bn2bin(k, secret_key, pub_key_len);
160 bn_free(dh->pub_key);
161 bn_free(dh->priv_key);
165 #define bn_new(bn) bn = BN_new() 166 #define bn_free(bn) BN_free(bn) 167 #define bn_set_word(bn, w) BN_set_word(bn, w) 168 #define bn_cmp(a, b) BN_cmp(a, b) 169 #define bn_copy(to, from) BN_copy(to, from) 170 #define bn_sub_word(bn, w) BN_sub_word(bn, w) 171 #define bn_cmp_1(bn) BN_cmp(bn, BN_value_one()) 172 #define bn_num_bytes(bn) BN_num_bytes(bn) 173 #define bn_bn2bin(bn, buf, len) BN_bn2bin(bn, buf) 174 #define bn_bin2bn(bn, buf, len) bn = BN_bin2bn(buf, len, 0) 175 #define bn_hex2bn(bn, buf, ret) ret = BN_hex2bn(&bn, buf) 176 #define bn_modexp(bn, y, q, p) \ 178 BN_CTX *ctx = BN_CTX_new(); \ 180 return AVERROR(ENOMEM); \ 181 if (!BN_mod_exp(bn, y, q, p, ctx)) { \ 183 return AVERROR(EINVAL); \ 188 #define dh_new() DH_new() 189 #define dh_generate_key(dh) DH_generate_key(dh) 190 #define dh_compute_key(dh, pub, len, secret) DH_compute_key(secret, pub, dh) 225 bn_modexp(bn, y, q, p);
242 if (!(dh = dh_new()))
249 bn_hex2bn(dh->p,
P1024, ret);
253 bn_set_word(dh->g, 2);
254 dh->length = key_len;
271 if (!dh_generate_key(dh))
274 bn_hex2bn(q1,
Q1024, ret);
295 len = bn_num_bytes(dh->pub_key);
296 if (len <= 0 || len > pub_key_len)
300 memset(pub_key, 0, pub_key_len);
301 bn_bn2bin(dh->pub_key, pub_key + pub_key_len - len, len);
307 int pub_key_len,
uint8_t *secret_key)
309 FFBigNum q1 =
NULL, pub_key_bn =
NULL;
313 bn_bin2bn(pub_key_bn, pub_key, pub_key_len);
318 bn_hex2bn(q1,
Q1024, ret);
327 }
else if ((ret = dh_compute_key(dh, pub_key_bn, pub_key_len,
uint32_t p[AV_BF_ROUNDS+2]
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.
static int dh_is_valid_public_key(FFBigNum y, FFBigNum p, FFBigNum q)
int ff_dh_generate_public_key(FF_DH *dh)
Generate a public key.
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
void ff_dh_free(FF_DH *dh)
Free a Diffie-Hellmann context.
av_cold FF_DH * ff_dh_init(int key_len)
Initialize a Diffie-Hellmann context.
int ff_dh_compute_shared_secret_key(FF_DH *dh, const uint8_t *pub_key, int pub_key_len, uint8_t *secret_key)
Compute the shared secret key from the private FF_DH value and the other party's public value...