--- a/server/utils.py	Thu Sep 06 15:03:52 2012 +0200
+++ b/server/utils.py	Mon Sep 10 15:08:55 2012 +0200
@@ -64,8 +64,11 @@
     # empty hash, accept any password for backwards compat
     if salt == '':
         return salt
-    if _CRYPTO_CTX.verify(passwd, salt):
-        return salt
+    try:
+        if _CRYPTO_CTX.verify(passwd, salt):
+            return salt
+    except ValueError: # e.g. couldn't identify hash
+        pass
     # wrong password
     return ''