Land #9900, add base64 encoder for ruby

modules/encoders/ruby/base64.rb

@@ -0,0 +1,34 @@
+##
+# This module requires Metasploit: https://metasploit.com/download
+# Current source: https://github.com/rapid7/metasploit-framework
+##
+
+class MetasploitModule < Msf::Encoder
+  Rank = GreatRanking
+
+  def initialize
+    super(
+      'Name'             => 'Ruby Base64 Encoder',
+      'Description'      => %q{
+        This encoder returns a base64 string encapsulated in
+        eval(%(base64 encoded string).unpack(%(m0)).first).
+      },
+      'Author'           => 'Robin Stenvi <robin.stenvi[at]gmail.com>',
+      'License'          => BSD_LICENSE,
+      'Arch'             => ARCH_RUBY)
+  end
+
+  def encode_block(state, buf)
+    %w{( ) . % e v a l u n p c k m 0 f i r s t}.each do |c|
+      raise BadcharError if state.badchars.include?(c)
+    end
+
+    b64 = Rex::Text.encode_base64(buf)
+
+    state.badchars.each_byte do |byte|
+      raise BadcharError if b64.include?(byte.chr)
+    end
+
+    return "eval(%(" + b64 + ").unpack(%(m0)).first)"
+  end
+end