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

or bogus DH parameters can be used for launching DOS attacks

diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c
index 718a9a481e7e8d4c1bab3e1127ad6dd052af15e4..df0300402e2dc54113b373c26f7cd2b869ed8154 100644 (file)
--- a/crypto/dh/dh_key.c
+++ b/crypto/dh/dh_key.c
@@ -135,13 +135,9 @@ 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 (!ENGINE_get_DH(dh->engine)->bn_mod_exp(dh, pub_key, dh->g,
-                       priv_key,dh->p,ctx,mont)) goto err;
-               }
-       while (BN_is_one(priv_key));
+       if (!BN_rand(priv_key, l, 0, 0)) goto err;
+       if (!ENGINE_get_DH(dh->engine)->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;