Add preserved_identifiers support

lib/msf/core/exploit/jsobfu.rb

@@ -8,7 +8,8 @@ module Msf
     def initialize(info={})
       super
       register_advanced_options([
-        OptInt.new('JsObfuscate', [false, "Number of times to obfuscate JavaScript", 0])
+        OptInt.new('JsObfuscate', [false, "Number of times to obfuscate JavaScript", 0]),
+        OptString.new('Identifiers', [false, "Identifiers to preserve for JsObfu"])
       ], Exploit::JSObfu)
     end
 
@@ -18,14 +19,20 @@ module Msf
     # @param js [String] JavaScript code
     # @param opts [Hash] obfuscation options
     #    * :iterations [FixNum] Number of times to obfuscate
+    #    * :preserved_identifiers [Array] An array of identifiers to preserve during obfuscation
     # @return [::Rex::Exploitation::JSObfu]
     #
     def js_obfuscate(js, opts={})
       iterations = (opts[:iterations] || datastore['JsObfuscate']).to_i
+      identifiers = (opts[:preserved_identifiers] || datastore['Identifiers'] || '').split(',')
       obfu = ::Rex::Exploitation::JSObfu.new(js)
-      obfu.obfuscate(:iterations=>iterations)
+      obfu_opts = {}
+      obfu_opts.merge!(iterations: iterations)
+      obfu_opts.merge!(preserved_identifiers: identifiers)
+
+      obfu.obfuscate(obfu_opts)
       obfu
     end
 
   end
-end
+end

tools/exploit/jsobfu.rb

@@ -32,6 +32,10 @@ module Jsobfu
           options[:output] = v
         end
 
+        opt.on('-p', '--preserved-identifiers id1,id2', 'The identifiers to preserve') do |v|
+          options[:preserved_identifiers] = v.split(',')
+        end
+
         opt.on_tail('-h', '--help', 'Show this message') do
           $stdout.puts opt
           exit
@@ -67,7 +71,10 @@ module Jsobfu
     def run
       original_js = read_js(@opts[:input])
       js = ::Rex::Exploitation::JSObfu.new(original_js)
-      js.obfuscate(:iterations=>@opts[:iteration].to_i)
+      obfu_opts = {}
+      obfu_opts.merge!(iterations: @opts[:iteration].to_i)
+      obfu_opts.merge!(preserved_identifiers: @opts[:preserved_identifiers] || [])
+      js.obfuscate(obfu_opts)
       js = js.to_s
 
       output_stream = $stdout