Commit e5cb2603 authored by Bodo Möller's avatar Bodo Möller
Browse files

DH key generation should not use a do ... while loop, 

or bogus DH parameters can be used for launching DOS attacks
parent 6aecef81

crypto/dh/dh_key.c

+3 −7
Original line number Original line Diff line number Diff line
@@ -135,13 +135,9 @@ static int generate_key(DH *dh) 




	l = dh->length ? dh->length : BN_num_bits(dh->p)-1; /* secret exponent length */

	l = dh->length ? dh->length : BN_num_bits(dh->p)-1; /* secret exponent length */





	do

		{

	if (!BN_rand(priv_key, l, 0, 0)) goto err;

	if (!BN_rand(priv_key, l, 0, 0)) goto err;

	if (!ENGINE_get_DH(dh->engine)->bn_mod_exp(dh, pub_key, dh->g,

	if (!ENGINE_get_DH(dh->engine)->bn_mod_exp(dh, pub_key, dh->g,

		priv_key,dh->p,ctx,mont)) goto err;

		priv_key,dh->p,ctx,mont)) goto err;

		}

	while (BN_is_one(priv_key));

		

		

	dh->pub_key=pub_key;

	dh->pub_key=pub_key;

	dh->priv_key=priv_key;

	dh->priv_key=priv_key;