1 files changed, 15 insertions, 1 deletions

diff --git a/src/lib/libcrypto/dsa/dsa_key.c b/src/lib/libcrypto/dsa/dsa_key.c
index 30607ca579..980b6dc2d3 100644
--- a/src/lib/libcrypto/dsa/dsa_key.c
+++ b/src/lib/libcrypto/dsa/dsa_key.c
@@ -90,8 +90,22 @@ int DSA_generate_key(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;