Better handling for incompatible Meterpreter extensions and commands (Round 2)

lib/rex/post/meterpreter/client_core.rb

@@ -309,15 +309,17 @@ def load_library(opts)
 
   #
   # Loads a meterpreter extension on the remote server instance and
-  # initializes the client-side extension handlers
+  # initializes the client-side extension handlers.
   #
-  #	Module
-  #		The module that should be loaded
+  # @param [String] mod The extension that should be loaded.
+  # @param [Hash] opts The options with which to load the extension.
+  # @option opts [String] LoadFromDisk Indicates that the library should be
+  #   loaded from disk, not from memory on the remote machine.
   #
-  #	LoadFromDisk
-  #		Indicates that the library should be loaded from disk, not from
-  #		memory on the remote machine
+  # @raise [RuntimeError] An exception is raised if the extension could not be
+  #   loaded.
   #
+  # @return [true] This always returns true or raises an exception.
   def use(mod, opts = { })
     if mod.nil?
       raise RuntimeError, "No modules were specified", caller
@@ -364,10 +366,11 @@ def use(mod, opts = { })
       end
 
       if path.nil? and image.nil?
+        error = Rex::Post::Meterpreter::ExtensionLoadError.new(name: mod.downcase)
         if Rex::Post::Meterpreter::ExtensionMapper.get_extension_names.include?(mod.downcase)
-          raise RuntimeError, "The \"#{mod.downcase}\" extension is not supported by this Meterpreter type (#{client.session_type})", caller
+          raise error, "The \"#{mod.downcase}\" extension is not supported by this Meterpreter type (#{client.session_type})", caller
         else
-          raise RuntimeError, "No module of the name #{modnameprovided} found", caller
+          raise error, "No module of the name #{modnameprovided} found", caller
         end
       end
 

lib/rex/post/meterpreter/extension.rb

@@ -4,6 +4,21 @@ module Rex
 module Post
 module Meterpreter
 
+#
+# An error that is raised when a particular Meterpreter extension can not be
+# loaded for any reason.
+#
+# @attr_reader [String] name The name of the extension that could not be loaded.
+class ExtensionLoadError < RuntimeError
+  attr_reader :name
+
+  # @param [String] name The name of the extension that could not be loaded.
+  def initialize(name:)
+    @name = name
+    super
+  end
+end
+
 ###
 #
 # Base class for all extensions that holds a reference to the

lib/rex/post/meterpreter/packet.rb

@@ -150,7 +150,6 @@ def self.generate_command_id_map_c
     powershell
     lanattacks
     peinjector
-    mimikatz
   })
 
   command_ids = id_map.map {|k, v| "#define COMMAND_ID_#{k.upcase} #{v}"}
@@ -234,7 +233,6 @@ def self.generate_command_id_map_python_extension
     powershell
     lanattacks
     peinjector
-    mimikatz
   })
   command_ids = id_map.map {|k, v| "COMMAND_ID_#{k.upcase} = #{v}"}
   %Q^
@@ -263,7 +261,6 @@ def self.generate_command_id_map_csharp
     powershell
     lanattacks
     peinjector
-    mimikatz
   })
   command_ids = id_map.map {|k, v| "#{k.split('_').map(&:capitalize).join} = #{v},"}
   %Q^

lib/rex/post/meterpreter/ui/console/command_dispatcher/core.rb

@@ -1320,9 +1320,45 @@ def cmd_load(*args)
         if (client.core.use(modulenameprovided) == true)
           add_extension_client(md)
         end
-      rescue
+      rescue => ex
         print_line
-        log_error("Failed to load extension: #{$!}")
+        log_error("Failed to load extension: #{ex.message}")
+        if ex.kind_of?(ExtensionLoadError) && ex.name
+          # MetasploitPayloads and MetasploitPayloads::Mettle do things completely differently, build an array of
+          # suggestion keys (binary_suffixes and Mettle build-tuples)
+          suggestion_keys = MetasploitPayloads.list_meterpreter_extension_suffixes(ex.name) + MetasploitPayloads::Mettle.available_platforms(ex.name)
+          suggestion_map = {
+            # Extension Suffixes
+            'jar' => 'java',
+            'php' => 'php',
+            'py' => 'python',
+            'x64.dll' => 'windows/x64',
+            'x86.dll' => 'windows',
+            # Mettle Platforms
+            'aarch64-iphone-darwin' => 'apple_ios/aarch64',
+            'aarch64-linux-musl' => 'linux/aarch64',
+            'arm-iphone-darwin' => 'apple_ios/armle',
+            'armv5b-linux-musleabi' => 'linux/armbe',
+            'armv5l-linux-musleabi' => 'linux/armle',
+            'i486-linux-musl' => 'linux/x86',
+            'mips64-linux-muslsf' => 'linux/mips64',
+            'mipsel-linux-muslsf' => 'linux/mipsle',
+            'mips-linux-muslsf' => 'linux/mipsbe',
+            'powerpc64le-linux-musl' => 'linux/ppc64le',
+            'powerpc-e500v2-linux-musl' => 'linux/ppce500v2',
+            'powerpc-linux-muslsf' => 'linux/ppc',
+            's390x-linux-musl' => 'linux/zarch',
+            'x86_64-apple-darwin' => 'osx/x64',
+            'x86_64-linux-musl' => 'linux/x64',
+          }
+          suggestions = suggestion_map.select { |k,_v| suggestion_keys.include?(k) }.values
+          unless suggestions.empty?
+            log_error("The \"#{ex.name}\" extension is supported by the following Meterpreter payloads:")
+            suggestions.each do |suggestion|
+              log_error("  - #{suggestion}/meterpreter*")
+            end
+          end
+        end
 
         next
       end
@@ -1762,6 +1798,27 @@ def self.client_extension_search_paths
     @@client_extension_search_paths
   end
 
+  def unknown_command(cmd, line)
+    status = super
+
+    if status.nil?
+      # Check to see if we can find this command in another extension. This relies on the core extension being the last
+      # in the dispatcher stack which it should be since it's the first loaded.
+      Rex::Post::Meterpreter::ExtensionMapper.get_extension_names.each do |ext_name|
+        next if extensions.include?(ext_name)
+        ext_klass = get_extension_client_class(ext_name)
+        next if ext_klass.nil?
+
+        if ext_klass.has_command?(cmd)
+          print_error("The \"#{cmd}\" command requires the \"#{ext_name}\" extension to be loaded (run: `load #{ext_name}`)")
+          return :handled
+        end
+      end
+    end
+
+    status
+  end
+
 protected
 
   attr_accessor :extensions # :nodoc:
@@ -1773,39 +1830,9 @@ def self.client_extension_search_paths
   # Loads the client extension specified in mod
   #
   def add_extension_client(mod)
-    loaded = false
-    klass = nil
-    self.class.client_extension_search_paths.each do |path|
-      path = ::File.join(path, "#{mod}.rb")
-      klass = CommDispatcher.check_hash(path)
-      if (klass == nil)
-        old   = CommDispatcher.constants
-        next unless ::File.exist? path
-
-        if (require(path))
-          new  = CommDispatcher.constants
-          diff = new - old
-
-          next if (diff.empty?)
-
-          klass = CommDispatcher.const_get(diff[0])
-
-          CommDispatcher.set_hash(path, klass)
-          loaded = true
-          break
-        else
-          print_error("Failed to load client script file: #{path}")
-          return false
-        end
+    klass = get_extension_client_class(mod)
 
-      else
-        # the klass is already loaded, from a previous invocation
-        loaded = true
-        break
-      end
-    end
-
-    unless loaded
+    if klass.nil?
       print_error("Failed to load client portion of #{mod}.")
       return false
     end
@@ -1817,6 +1844,29 @@ def add_extension_client(mod)
     self.extensions << mod
   end
 
+  def get_extension_client_class(mod)
+    self.class.client_extension_search_paths.each do |path|
+      path = ::File.join(path, "#{mod}.rb")
+      klass = CommDispatcher.check_hash(path)
+      return klass unless klass.nil?
+
+      old = CommDispatcher.constants
+      next unless ::File.exist? path
+
+      return nil unless require(path)
+
+      new  = CommDispatcher.constants
+      diff = new - old
+
+      next if (diff.empty?)
+
+      klass = CommDispatcher.const_get(diff[0])
+
+      CommDispatcher.set_hash(path, klass)
+      return klass
+    end
+  end
+
   def tab_complete_modules(str, words)
     tabs = []
     client.framework.modules.post.map do |name,klass|

lib/rex/post/meterpreter/ui/console/command_dispatcher/extapi.rb

@@ -32,6 +32,10 @@ class Console::CommandDispatcher::Extapi
 
   include Console::CommandDispatcher
 
+  def self.has_command?(name)
+    Dispatchers.any? { |klass| klass.has_command?(name) }
+  end
+
   #
   # Initializes an instance of the extended API command interaction.
   #

lib/rex/post/meterpreter/ui/console/command_dispatcher/lanattacks.rb

@@ -26,6 +26,10 @@ class Console::CommandDispatcher::Lanattacks
 
   include Console::CommandDispatcher
 
+  def self.has_command?(name)
+    Dispatchers.any? { |klass| klass.has_command?(name) }
+  end
+
   #
   # Initializes an instance of the lanattacks command interaction.
   #

lib/rex/post/meterpreter/ui/console/command_dispatcher/priv.rb

@@ -28,6 +28,10 @@ class Console::CommandDispatcher::Priv
 
   include Console::CommandDispatcher
 
+  def self.has_command?(name)
+    Dispatchers.any? { |klass| klass.has_command?(name) }
+  end
+
   #
   # Initializes an instance of the priv command interaction.
   #

lib/rex/post/meterpreter/ui/console/command_dispatcher/stdapi.rb

@@ -37,6 +37,10 @@ class Console::CommandDispatcher::Stdapi
 
   include Console::CommandDispatcher
 
+  def self.has_command?(name)
+    Dispatchers.any? { |klass| klass.has_command?(name) }
+  end
+
   #
   # Initializes an instance of the stdapi command interaction.
   #

lib/rex/ui/text/dispatcher_shell.rb

@@ -28,6 +28,29 @@ module DispatcherShell
   ###
   module CommandDispatcher
 
+    module ClassMethods
+      #
+      # Check whether or not the command dispatcher is capable of handling the
+      # specified command. The command may still be disabled through some means
+      # at runtime.
+      #
+      # @param [String] name The name of the command to check.
+      # @return [Boolean] true if the dispatcher can handle the command.
+      def has_command?(name)
+        self.method_defined?("cmd_#{name}")
+      end
+
+      def included(base)
+        # Propagate the included hook
+        CommandDispatcher.included(base)
+      end
+    end
+
+    def self.included(base)
+      # Install class methods so they are inheritable
+      base.extend(ClassMethods)
+    end
+
     #
     # Initializes the command dispatcher mixin.
     #
@@ -539,7 +562,7 @@ def run_command(dispatcher, method, arguments)
   # If the command is unknown...
   #
   def unknown_command(method, line)
-    print_error("Unknown command: #{method}.")
+    print_error("Unknown command: #{method}")
   end
 
   #