From b2f0f37d242f1194fe1f886557cf6cefdf98caf6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Storsj=C3=B6?= Date: Fri, 29 May 2015 10:14:39 +0300 Subject: [PATCH] rtmpdh: Generate the whole private exponent using av_get_random_seed() with nettle/gmp MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Don't use a PRNG for generating it; that defies the intended use within the cryptograhic handshake. Signed-off-by: Martin Storsjö --- libavformat/rtmpdh.c | 16 +++++++++------- 1 file 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)