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authorMartin Storsjö <martin@martin.st>2015-05-29 10:14:39 +0300
committerMartin Storsjö <martin@martin.st>2015-05-29 23:33:03 +0300
commitb2f0f37d242f1194fe1f886557cf6cefdf98caf6 (patch)
tree7ec7389edbbe8fa171f040fbd39c199eb70d5320
parente9e86d9ef637f5a600c76b352ffe5a82b71b25d1 (diff)
downloadffmpeg-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.c16
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)