fix error found by coverity: check if ctx is != NULL before calling BN_CTX_end()

[oweals/openssl.git] / crypto / dsa / dsa_key.c

diff --git a/crypto/dsa/dsa_key.c b/crypto/dsa/dsa_key.c
index 8427b77970dafa066bdc5ee810380013423fb54a..0423f2e00cd254c103293e7c67a57dbd6f2a80d0 100644 (file)
--- a/crypto/dsa/dsa_key.c
+++ b/crypto/dsa/dsa_key.c
@@ -98,8 +98,22 @@ static int dsa_builtin_keygen(DSA *dsa)
                }
        else
                pub_key=dsa->pub_key;
+       
+       {
+               BIGNUM local_prk;
+               BIGNUM *prk;
+
+               if ((dsa->flags & DSA_FLAG_NO_EXP_CONSTTIME) == 0)
+                       {
+                       BN_init(&local_prk);
+                       prk = &local_prk;
+                       BN_with_flags(prk, priv_key, BN_FLG_EXP_CONSTTIME);
+                       }
+               else
+                       prk = priv_key;
 
-       if (!BN_mod_exp(pub_key,dsa->g,priv_key,dsa->p,ctx)) goto err;
+               if (!BN_mod_exp(pub_key,dsa->g,prk,dsa->p,ctx)) goto err;
+       }
 
        dsa->priv_key=priv_key;
        dsa->pub_key=pub_key;