Add a proper rex-based service for the SMB server

Gemfile

@@ -52,3 +52,6 @@ group :test do
   # Manipulate Time.now in specs
   gem 'timecop'
 end
+
+# remove after https://github.com/rapid7/ruby_smb/pull/260 is landed
+gem 'ruby_smb', git: 'https://github.com/zeroSteiner/ruby_smb', branch: 'feat/server/remove-share'

Gemfile.lock

@@ -1,3 +1,15 @@
+GIT
+  remote: https://github.com/zeroSteiner/ruby_smb
+  revision: feba8f6592c33c252c6b4e5dd576f2722ada6bf2
+  branch: feat/server/remove-share
+  specs:
+    ruby_smb (3.3.2)
+      bindata
+      openssl-ccm
+      openssl-cmac
+      rubyntlm
+      windows_error (>= 0.1.4)
+
 PATH
   remote: .
   specs:
@@ -473,12 +485,6 @@ GEM
     ruby-progressbar (1.13.0)
     ruby-rc4 (0.1.5)
     ruby2_keywords (0.0.5)
-    ruby_smb (3.3.1)
-      bindata
-      openssl-ccm
-      openssl-cmac
-      rubyntlm
-      windows_error (>= 0.1.4)
     rubyntlm (0.6.3)
     rubyzip (2.3.2)
     sawyer (0.9.2)
@@ -565,6 +571,7 @@ DEPENDENCIES
   rspec-rerun
   rubocop
   ruby-prof (= 1.4.2)
+  ruby_smb!
   simplecov (= 0.18.2)
   test-prof
   timecop

lib/msf/core/exploit/remote/smb/server.rb

@@ -45,19 +45,6 @@ module Msf
       def on_client_connect(client)
         vprint_status("Received SMB connection from #{client.peerhost}")
       end
-
-      def cleanup_service
-        if service
-          begin
-            self.service.stop
-            self.service.wait
-            true
-          rescue ::Exception => e
-            print_error(e.message)
-            false
-          end
-        end
-      end
     end
   end
 end

lib/msf/core/exploit/remote/smb/server/share.rb

@@ -28,9 +28,9 @@ module Msf
         register_options(
           [
             OptPort.new('SRVPORT',    [ true, 'The local port to listen on.', 445 ]),
-            OptString.new('SHARE', [ false, 'Share (Default Random)']),
-            OptString.new('FILE_NAME', [ false, 'File name to share (Default Random)']),
-            OptString.new('FOLDER_NAME', [ false, 'Folder name to share (Default none)'])
+            OptString.new('SHARE', [ false, 'Share (Default: random); cannot contain spaces or slashes'], regex: /^[^\s\/\\]*$/),
+            OptString.new('FILE_NAME', [ false, 'File name to share (Default: random)']),
+            OptString.new('FOLDER_NAME', [ false, 'Folder name to share (Default: none)'])
           ], Msf::Exploit::Remote::SMB::Server::Share)
         register_advanced_options(
           [
@@ -58,12 +58,18 @@ module Msf
 
         super(opts)
 
-        virtual_disk = RubySMB::Server::Share::Provider::VirtualDisk.new(@share)
-        # the virtual disk expects the path to use the native File::SEPARATOR so normalize on that here
-        virtual_disk.add_dynamic_file("#{@folder_name}#{File::SEPARATOR}#{@file_name}".gsub(/\/|\\/, File::SEPARATOR)) do |client, _smb_session|
-          get_file_contents(client: client)
+        if share.present?
+          if service.shares.key?(share)
+            fail_with(Msf::Module::Failure::BadConfig, "The specified SMB share '#{share}' already exists.")
+          end
+
+          virtual_disk = RubySMB::Server::Share::Provider::VirtualDisk.new(share)
+          # the virtual disk expects the path to use the native File::SEPARATOR so normalize on that here
+          virtual_disk.add_dynamic_file("#{@folder_name}#{File::SEPARATOR}#{@file_name}".gsub(/\/|\\/, File::SEPARATOR)) do |client, _smb_session|
+            get_file_contents(client: client)
+          end
+          service.add_share(virtual_disk)
         end
-        service.add_share(virtual_disk)
       end
 
       # Setups the server configuration.
@@ -71,8 +77,8 @@ module Msf
         super
 
         self.folder_name = datastore['FOLDER_NAME']
-        self.share = datastore['SHARE'] || Rex::Text.rand_text_alpha(4 + rand(3))
-        self.file_name = datastore['FILE_NAME'] || Rex::Text.rand_text_alpha(4 + rand(3))
+        self.share = datastore['SHARE'].present? ? datastore['SHARE'] : Rex::Text.rand_text_alpha(4 + rand(3))
+        self.file_name = datastore['FILE_NAME'].present? ? datastore['FILE_NAME'] : Rex::Text.rand_text_alpha(4 + rand(3))
       end
 
       # Builds the UNC Name for the shared file
@@ -92,6 +98,12 @@ module Msf
       def get_file_contents(client:)
         file_contents
       end
+
+      def cleanup
+        self.service.remove_share(share) if share.present?
+
+        super
+      end
     end
   end
 end

lib/rex/proto/smb/server.rb

@@ -18,7 +18,7 @@ class Server
   include Proto
   extend Forwardable
 
-  def_delegators :@rubysmb_server, :add_share, :dialects, :guid, :shares
+  def_delegators :@rubysmb_server, :dialects, :guid, :shares, :add_share, :remove_share
 
   def initialize(port = 445, listen_host = '0.0.0.0', context = {}, comm = nil, gss_provider: nil, logger: nil)
     self.listen_host     = listen_host
@@ -99,10 +99,6 @@ class Server
     @listener_thread.join if @listener_thread
   end
 
-  def add_share(share_provider, *arg)
-
-  end
-
   attr_accessor :context, :comm, :listener, :listen_host, :listen_port, :on_client_connect_proc
 end
 

lib/rex/service_manager.rb

@@ -59,7 +59,7 @@ class ServiceManager < Hash
       return inst
     end
 
-    inst = klass.new(*args)
+    inst = klass.new(*args, **kwargs)
     als  = inst.alias
 
     # Find an alias that isn't taken.