Don't preserve existing keys in DH_generate_key.

[openssl.git] / crypto / dh / dh_key.c

diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c
index 91af882e43356860459ddd4a91e6025c405b74c2..718a9a481e7e8d4c1bab3e1127ad6dd052af15e4 100644 (file)
--- a/crypto/dh/dh_key.c
+++ b/crypto/dh/dh_key.c
@@ -101,6 +101,7 @@ const DH_METHOD *DH_OpenSSL(void)
 static int generate_key(DH *dh)
        {
        int ok=0;
+       unsigned l;
        BN_CTX *ctx;
        BN_MONT_CTX *mont;
        BIGNUM *pub_key=NULL,*priv_key=NULL;
@@ -112,9 +113,6 @@ static int generate_key(DH *dh)
                {
                priv_key=BN_new();
                if (priv_key == NULL) goto err;
-               do
-                       if (!BN_rand_range(priv_key, dh->p)) goto err;
-               while (BN_is_zero(priv_key));
                }
        else
                priv_key=dh->priv_key;
@@ -135,9 +133,15 @@ static int generate_key(DH *dh)
                }
        mont=(BN_MONT_CTX *)dh->method_mont_p;
 
-       if (!ENGINE_get_DH(dh->engine)->bn_mod_exp(dh, pub_key, dh->g,
-                               priv_key,dh->p,ctx,mont))
-               goto err;
+       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));
                
        dh->pub_key=pub_key;
        dh->priv_key=priv_key;