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| author | Martin Storsjö <martin@martin.st> | 2015-05-29 10:14:39 +0300 |
|---|---|---|
| committer | Martin Storsjö <martin@martin.st> | 2015-05-29 23:33:03 +0300 |
| commit | b2f0f37d242f1194fe1f886557cf6cefdf98caf6 (patch) | |
| tree | 7ec7389edbbe8fa171f040fbd39c199eb70d5320 | |
| parent | e9e86d9ef637f5a600c76b352ffe5a82b71b25d1 (diff) | |
| download | ffmpeg-b2f0f37d242f1194fe1f886557cf6cefdf98caf6.tar.gz | |
rtmpdh: Generate the whole private exponent using av_get_random_seed() with nettle/gmp
Don't use a PRNG for generating it; that defies the intended use
within the cryptograhic handshake.
Signed-off-by: Martin Storsjö <martin@martin.st>
| -rw-r--r-- | libavformat/rtmpdh.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/libavformat/rtmpdh.c b/libavformat/rtmpdh.c index 5cc66c9ec1..12a64bcdd9 100644 --- a/libavformat/rtmpdh.c +++ b/libavformat/rtmpdh.c @@ -81,13 +81,15 @@ ret = 1; \ } while (0) #define bn_modexp(bn, y, q, p) mpz_powm(bn, y, q, p) -#define bn_random(bn, num_bits) \ - do { \ - gmp_randstate_t rs; \ - gmp_randinit_mt(rs); \ - gmp_randseed_ui(rs, av_get_random_seed()); \ - mpz_urandomb(bn, rs, num_bits); \ - gmp_randclear(rs); \ +#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) #elif CONFIG_GCRYPT #define bn_new(bn) bn = gcry_mpi_new(1) |