diff --git a/run/sshng2john.py b/run/sshng2john.py
index 12a6f60..27fbcf7 100755
--- a/run/sshng2john.py
+++ b/run/sshng2john.py
@@ -31,10 +31,18 @@ from hashlib import md5 as MD5
 
 limited = False
 
+
+class Object(object):
+    pass
+
 try:
     from Crypto.Cipher import DES3, AES
 except ImportError:
     print >> sys.stderr, "PyCrypto is missing in your Python installation, %s is operating is limited features mode!" % sys.argv[0]
+    AES = Object()
+    AES.MODE_CBC = ""
+    DES3 = Object()
+    DES3.MODE_CBC = ""
     limited = True
 
 
@@ -639,7 +647,8 @@ class PKey (object):
 
         if 'proc-type' not in headers:
             # unencryped: done
-            return data
+            print >> sys.stderr, "%s has no password!" % f.name
+            return None
         # encrypted keyfile: will need a password
         if headers['proc-type'] != '4,ENCRYPTED':
             raise SSHException('Unknown private key structure "%s"' % headers['proc-type'])
@@ -674,7 +683,7 @@ class PKey (object):
                 return ddata
             except ValueError:  # incorrect password
                 return data
-        return None
+        return self.hash  # dummy value
 
 
 def chunks(l, n):
@@ -717,6 +726,8 @@ class RSADSSKey (PKey):
     def _from_private_key_file(self, filename, password):
         data = self._read_private_key_file('RSA', filename, password)
 
+        if not data:
+            return
         if limited:
             print self.hash
             return