Add select_cmdstager

lib/msf/core/exploit/cmdstager.rb

@@ -15,14 +15,38 @@ module Exploit::CmdStager
   include Msf::Exploit::EXE
 
   STAGERS = {
-    :bourne => Rex::Exploitation::CmdStagerBourne,
-    :debug_asm => Rex::Exploitation::CmdStagerDebugAsm,
-    :debug_write => Rex::Exploitation::CmdStagerDebugWrite,
-    :echo => Rex::Exploitation::CmdStagerEcho,
-    :printf => Rex::Exploitation::CmdStagerPrintf,
-    :vbs => Rex::Exploitation::CmdStagerVBS,
-    :vbs_adodb => Rex::Exploitation::CmdStagerVBS,
-    :tftp => Rex::Exploitation::CmdStagerTFTP
+    :bourne => {
+      :klass => Rex::Exploitation::CmdStagerBourne,
+      :decoder => false
+    },
+    :debug_asm => {
+      :klass => Rex::Exploitation::CmdStagerDebugAsm,
+      :decoder => true
+    },
+    :debug_write => {
+      :klass => Rex::Exploitation::CmdStagerDebugWrite,
+      :decoder => true
+    },
+    :echo => {
+      :klass => Rex::Exploitation::CmdStagerEcho,
+      :decoder => false
+    },
+    :printf => {
+      :klass => Rex::Exploitation::CmdStagerPrintf,
+      :decoder => false
+    },
+    :vbs => {
+      :klass => Rex::Exploitation::CmdStagerVBS,
+      :decoder => true
+    },
+    :vbs_adodb => {
+      :klass => Rex::Exploitation::CmdStagerVBS,
+      :decoder => true
+    },
+    :tftp => {
+      :klass => Rex::Exploitation::CmdStagerTFTP,
+      :decoder => false
+    }
   }
 
   STUBS = {
@@ -54,7 +78,8 @@ module Exploit::CmdStager
   end
 
 
-  # Executes the command stager while showing the progress
+  # Executes the command stager while showing the progress. This method should
+  # be called from exploits using this mixin.
   #
   # @param opts [Hash] Hash containing configuration options. Also allow to
   #   send opts to the Rex::Exploitation::CmdStagerBase constructor.
@@ -63,28 +88,14 @@ module Exploit::CmdStager
   # @option opts :delay [Float] Delay between command executions.
   # @option opts :code [String] Payload to embed into the resultant executable.
   # @return [void]
-  # @raise [ArgumentError] raised if a valid CMD Stager can not be found or
-  #   it isn't compatible with the target.
   def execute_cmdstager(opts = {})
-    # Select the correct flavor
-    select_flavor(opts)
-    raise ArgumentError, "Unable to select CMD Stager" if flavor.nil?
-    raise ArgumentError, "The CMD Stager selected isn't compatible with the target" unless compatible_flavor?
-
-    # Select the correct decoder
-    select_decoder_stub(opts)
-
-    # Generate the CMD stager list of commands
     self.cmd_list = generate_cmdstager(opts)
 
-    # If the stager needs to do additional setup...
     stager_instance.setup(self)
 
-    # Execute it... ensuring the stager gets a chance to cleanup
     begin
       execute_cmdstager_begin(opts)
 
-
       sent = 0
       total_bytes = 0
       cmd_list.each { |cmd| total_bytes += cmd.length }
@@ -114,13 +125,12 @@ module Exploit::CmdStager
   # and platform.
   #
   def generate_cmdstager(opts = {}, pl = nil)
-
-    opts[:decoder] = decoder_stub unless opts.include?(:decoder)
+    select_cmdstager(opts)
 
     self.exe = generate_payload_exe(:code => pl)
 
     self.stager_instance = create_stager
-    cmd_list = stager_instance.generate(opts)
+    cmd_list = stager_instance.generate(opts_with_decoder(opts))
 
     if (cmd_list.nil? or cmd_list.length < 1)
       print_error("The command stager could not be generated")
@@ -130,6 +140,21 @@ module Exploit::CmdStager
     cmd_list
   end
 
+  def select_cmdstager(opts = {})
+    select_flavor(opts)
+    raise ArgumentError, "Unable to select CMD Stager" if flavor.nil?
+    raise ArgumentError, "The CMD Stager selected isn't compatible with the target" unless compatible_flavor?
+    select_decoder_stub(opts)
+    raise ArgumentError, "Unable to select decoder stub" if decoder_stub.nil? and stub_required?
+  end
+
+  def opts_with_decoder(opts = {})
+    return opts if opts.include?(:decoder)
+    return opts.merge(:decoder => decoder_stub) if decoder_stub
+
+    opts
+  end
+
 
   #
   # Show the progress of the upload
@@ -144,7 +169,7 @@ module Exploit::CmdStager
   # Create an instance of the flavored stager
   #
   def create_stager
-    STAGERS[flavor].new(exe)
+    STAGERS[flavor][:klass].new(exe)
   end
 
   #
@@ -157,6 +182,10 @@ module Exploit::CmdStager
     STUBS[flavor]
   end
 
+  def stub_required?
+    STAGERS[flavor][:decoder]
+  end
+
   #
   # 1 - Use the decoder provided by the module source
   # 2 - Use the decoder by the user through datastore
@@ -233,6 +262,8 @@ module Exploit::CmdStager
   end
   def execute_cmdstager_end(opts)
   end
+  def execute_command(cmd, opts)
+  end
 
 end