Fix incorrect check in DL key check

get_q returns zero instead of throwing if q is not set

1 files changed, 3 insertions, 6 deletions

diff --git a/src/lib/pubkey/dl_algo/dl_algo.cpp b/src/lib/pubkey/dl_algo/dl_algo.cpp
index 0ac6bfce5..c5fc1e082 100644
--- a/src/lib/pubkey/dl_algo/dl_algo.cpp
+++ b/src/lib/pubkey/dl_algo/dl_algo.cpp
@@ -75,16 +75,13 @@ bool DL_Scheme_PublicKey::check_key(RandomNumberGenerator& rng,
    if(!m_group.verify_group(rng, strong))
       return false;
 
-   try
+   const BigInt& q = group_q();
+
+   if(q.is_zero() == false)
       {
-      const BigInt& q = group_q();
       if(power_mod(m_y, q, p) != 1)
          return false;
       }
-   catch(const Invalid_State&)
-      {
-      return true;
-      }
 
    return true;
    }