Adding count-based print message

This commit removes the creation of a separate, timed
thread for printing out status messages to the user
in the case of large PASS_FILEs.  This adjustment eliminates
the overheard of context switching associated with
spinning off separate threads, as well as the dangers
associated with the Thread#kill method.

Author: nstarke

lib/msf/core/auxiliary/auth_brute.rb

@@ -331,22 +331,6 @@ def combine_users_and_passwords(user_array,pass_array)
 
     creds = [ [], [], [], [] ] # userpass, pass, user, rest
     remaining_pairs = combined_array.length # counter for our occasional output
-    status = Thread.new do
-      loop do
-        # Ruby's sleep function is not terribly accurate.
-        # Since all we are trying to do is let the user know
-        # that the process is still working and giving them
-        # an estimate as to how many pairs are left,
-        # precision may not be of the utmost necessity
-        sleep 100
-        # Let the user know the combined pair list is still building
-        # and tell them how many pairs are left to process.
-        print_brute(
-          :level => :vstatus,
-          :msg => "Pair list is still building with #{remaining_pairs} pairs left to process"
-        )
-      end
-    end
     # Move datastore['USERNAME'] and datastore['PASSWORD'] to the front of the list.
     # Note that we cannot tell the user intention if USERNAME or PASSWORD is blank --
     # maybe (and it's often) they wanted a blank. One more credential won't kill
@@ -361,9 +345,14 @@ def combine_users_and_passwords(user_array,pass_array)
       else
         creds[3] << pair
       end
+      if remaining_pairs % 500000 == 0
+        print_brute(
+          :level => :vstatus,
+          :msg => "Pair list is still building with #{remaining_pairs} pairs left to process"
+        )
+      end
       remaining_pairs -= 1
     end
-    status.kill
     return creds[0] + creds[1] + creds[2] + creds[3]
   end