Commit 746142d6 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 475e21bc

crypto/dh/dh_key.c

+2 −7
Original line number Diff line number Diff line
@@ -132,13 +132,8 @@ static int generate_key(DH *dh) 


	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 (!dh->meth->bn_mod_exp(dh, pub_key,dh->g,priv_key,dh->p,&ctx,mont))

			goto err;

 		}

	while (BN_is_one(priv_key));

	if (!dh->meth->bn_mod_exp(dh, pub_key,dh->g,priv_key,dh->p,&ctx,mont)) goto err;

		

	dh->pub_key=pub_key;

	dh->priv_key=priv_key;