Land rapid7#3313, progress feedback for PASS_FILE

[FixRM rapid7#8704]

Author: wvu

lib/msf/core/auxiliary/auth_brute.rb

@@ -330,6 +330,9 @@ def combine_users_and_passwords(user_array,pass_array)
     end
 
     creds = [ [], [], [], [] ] # userpass, pass, user, rest
+    remaining_pairs = combined_array.length # counter for our occasional output
+    interval = 60 # seconds between each remaining pair message reported to user
+    next_message_time = Time.now + interval # initial timing interval for user message
     # 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
@@ -344,6 +347,14 @@ def combine_users_and_passwords(user_array,pass_array)
       else
         creds[3] << pair
       end
+      if Time.now > next_message_time
+        print_brute(
+          :level => :vstatus,
+          :msg => "Pair list is still building with #{remaining_pairs} pairs left to process"
+        )
+        next_message_time = Time.now + interval
+      end
+      remaining_pairs -= 1
     end
     return creds[0] + creds[1] + creds[2] + creds[3]
   end