anchor.diff:  %%           current time plus the configured sipauth_password.
   %% Returns : string()
   %%--------------------------------------------------------------------
  -get_nonce(Timestamp) ->
  -    hex:to(erlang:md5(Timestamp ++ ":" ++ sipserver:get_env(sipauth_password, ""))).
  +get_nonce(Timestamp) when is_list(Timestamp) ->
  +    hex:to(erlang:md5([Timestamp, ":", sipserver:get_env(sipauth_password, "")])).
   
   %%--------------------------------------------------------------------
   %% Function: get_challenge()
  
positive.code: 			    {false, User, Class};
  			true ->
  			    {true, User, Class}
  		    end;
  		Unknown ->
  		    logger:log(error, "Auth: Unknown result from get_user_verified_proxy: ~p", [Unknown]),
  		    {false, none, Class}
  	    end
      end.
  
  
negative.code: %%           check if this user may use this Address.
  %% Returns : {Allowed, User, Class}
  %%           Allowed = true | false
  %%           User    = unknown | none | string(), SIP authentication
  %%                     username
  %%           Class   = atom(), the class that this ToNumberIn matched
  %%--------------------------------------------------------------------
  pstn_call_check_auth(Method, Header, URL, ToNumberIn, Classdefs)
  