experimental: stages encoded by default, set DisableStageEncoding 1 to disable

git-svn-id: file:///home/svn/framework3/trunk@5511 4d416f70-5f16-0410-b530-b9f4589650da

lib/msf/core/encoded_payload.rb

@@ -16,11 +16,11 @@ class EncodedPayload
 	# This method creates an encoded payload instance and returns it to the
 	# caller.
 	#
-	def self.create(pinst, reqs)
+	def self.create(pinst, reqs = {})
 		# Create the encoded payload instance
 		p = EncodedPayload.new(pinst.framework, pinst, reqs)
 
-		p.generate
+		p.generate(reqs['Raw'])
 
 		return p
 	end
@@ -38,8 +38,8 @@ class EncodedPayload
 	# This method enerates the full encoded payload and returns the encoded
 	# payload buffer.
 	#
-	def generate
-		self.raw           = nil
+	def generate(raw = nil)
+		self.raw           = raw
 		self.encoded       = nil
 		self.nop_sled_size = 0
 		self.nop_sled      = nil
@@ -60,7 +60,7 @@ class EncodedPayload
 			pinst.validate()
 
 			# Generate the raw version of the payload first
-			generate_raw()
+			generate_raw() if self.raw.nil?
 
 			# Encode the payload
 			encode()
@@ -100,7 +100,7 @@ class EncodedPayload
 	def encode
 		# If the exploit has bad characters, we need to run the list of encoders
 		# in ranked precedence and try to encode without them.
-		if (reqs['BadChars'] or reqs['Encoder'])
+		if reqs['BadChars'] or reqs['Encoder'] or reqs['ForceEncode']
 			encoders = pinst.compatible_encoders
 
 			# If the caller had a preferred encoder, try to find it and prefix it

lib/msf/core/payload/stager.rb

@@ -74,6 +74,9 @@ module Msf::Payload::Stager
 		# Substitute variables in the stage
 		substitute_vars(p, stage_offsets) if (stage_offsets)
 
+		# Encode the stage of stage encoding is enabled
+		p = encode_stage(p)
+
 		return p
 	end
 
@@ -133,6 +136,25 @@ module Msf::Payload::Stager
 		false
 	end
 
+	# Encodes the stage prior to transmission
+	def encode_stage(stg)
+
+		# If DisableStageEncoding is set, we do not encode the stage
+		return stg if datastore['DisableStageEncoding'] =~ /^(y|1|t)/i
+
+		# Generate an encoded version of the stage.  We tell the encoding system
+		# to save edi to ensure that it does not get clobbered.
+		encp = Msf::EncodedPayload.create(
+			self, 
+			'Raw'           => stg,
+			'SaveRegisters' => ['edi'],
+			'ForceEncode'   => true)
+
+		# If the encoding succeeded, use the encoded buffer.  Otherwise, fall
+		# back to using the non-encoded stage
+		encp.encoded || stg
+	end
+
 	# Aliases
 	alias stager_payload payload
 	alias stager_offsets offsets