Test case for passphrases with null characters

Add a functional test to make sure the system
properly accepts passphrases with null characters.

Author: john-moffett

test/functional/wallet_encryption.py

@@ -90,6 +90,17 @@ def run_test(self):
         self.nodes[0].walletpassphrase(passphrase2, MAX_VALUE + 1000)
         actual_time = self.nodes[0].getwalletinfo()['unlocked_until']
         assert_equal(actual_time, expected_time)
+        self.nodes[0].walletlock()
+
+        # Test passphrase with null characters
+        passphrase_with_nulls = "Phrase\0With\0Nulls"
+        self.nodes[0].walletpassphrasechange(passphrase2, passphrase_with_nulls)
+        # walletpassphrasechange should not stop at null characters
+        assert_raises_rpc_error(-14, "wallet passphrase entered was incorrect", self.nodes[0].walletpassphrase, passphrase_with_nulls.partition("\0")[0], 10)
+        self.nodes[0].walletpassphrase(passphrase_with_nulls, 10)
+        sig = self.nodes[0].signmessage(address, msg)
+        assert self.nodes[0].verifymessage(address, sig, msg)
+        self.nodes[0].walletlock()
 
 
 if __name__ == '__main__':