#
# An NTLM Authentication Library for Ruby
#
# This code is a derivative of "dbf2.rb" written by yrock
# and Minero Aoki. You can find original code here:
# http://jp.rubyist.net/magazine/?0013-CodeReview
# -------------------------------------------------------------
# Copyright (c) 2005,2006 yrock
# 
# This program is free software.
# You can distribute/modify this program under the terms of the
# Ruby License.
#
# 2011-03-08 improved through a code merge with Metasploit's SMB::Crypt
# -------------------------------------------------------------
#
# 2011-02-23 refactored and improved by Alexandre Maloteaux for Metasploit Project
# -------------------------------------------------------------
#
# 2006-02-11 refactored by Minero Aoki
# -------------------------------------------------------------
#
# All protocol information used to write this code stems from
# "The NTLM Authentication Protocol" by Eric Glass. The author 
# would thank to him for this tremendous work and making it 
# available on the net.
# http://davenport.sourceforge.net/ntlm.html
# -------------------------------------------------------------
# Copyright (c) 2003 Eric Glass
#
# Permission to use, copy, modify, and distribute this document
# for any purpose and without any fee is hereby granted,
# provided that the above copyright notice and this list of
# conditions appear in all copies. 
# -------------------------------------------------------------
#
# The author also looked Mozilla-Firefox-1.0.7 source code,
# namely, security/manager/ssl/src/nsNTLMAuthModule.cpp and
# Jonathan Bastien-Filiatrault's libntlm-ruby.
# "http://x2a.org/websvn/filedetails.php?
# repname=libntlm-ruby&path=%2Ftrunk%2Fntlm.rb&sc=1"
# The latter has a minor bug in its separate_keys function.
# The third key has to begin from the 14th character of the 
# input string instead of 13th:)
#--
# $Id: ntlm.rb 11678 2011-01-30 19:26:35Z hdm $
#++


require 'rex/proto/ntlm/constants'
require 'rex/proto/ntlm/base'

module Rex
module Proto
module NTLM
class Crypt

CONST = Rex::Proto::NTLM::Constants
BASE = Rex::Proto::NTLM::Base

	@@loaded_openssl = false
	
	begin
		require 'openssl'
		require 'openssl/digest'
		@@loaded_openssl = true
	rescue ::Exception
	end

	def self.gen_keys(str)
		str.scan(/.{7}/).map{ |key| des_56_to_64(key) }
	end
 
	def self.des_56_to_64(ckey56s)
		ckey64 = []
		ckey56 = ckey56s.unpack('C*')
		ckey64[0] = ckey56[0]
		ckey64[1] = ((ckey56[0] << 7) & 0xFF) | (ckey56[1] >> 1)
		ckey64[2] = ((ckey56[1] << 6) & 0xFF) | (ckey56[2] >> 2)
		ckey64[3] = ((ckey56[2] << 5) & 0xFF) | (ckey56[3] >> 3)
		ckey64[4] = ((ckey56[3] << 4) & 0xFF) | (ckey56[4] >> 4)
		ckey64[5] = ((ckey56[4] << 3) & 0xFF) | (ckey56[5] >> 5)
		ckey64[6] = ((ckey56[5] << 2) & 0xFF) | (ckey56[6] >> 6)
		ckey64[7] =  (ckey56[6] << 1) & 0xFF
		ckey64.pack('C*')
	end
	     
	def self.apply_des(plain, keys)
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
		dec = OpenSSL::Cipher::DES.new
		keys.map do |k|
			dec.key = k
			dec.encrypt.update(plain)
		end
	end
      
	def self.lm_hash(password, half = false)
		size = half ? 7 : 14
		keys = gen_keys(password.upcase.ljust(size, "\0"))
		apply_des(CONST::LM_MAGIC, keys).join
	end   
      
	def self.ntlm_hash(password, opt = {})
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
		pwd = password.dup
		unless opt[:unicode]
			pwd = Rex::Text.to_unicode(pwd)
		end
		OpenSSL::Digest::MD4.digest(pwd)
	end
	
	# This hash is used for lmv2/ntlmv2 response calculation
	def self.ntlmv2_hash(user, password, domain, opt={})
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
		
		if opt[:pass_is_hash]
			ntlmhash = password
		else
			ntlmhash = ntlm_hash(password, opt)
		end
		
		# With Win 7 and maybe other OSs we sometimes get the domain not uppercased
		userdomain = user.upcase  + domain
		unless opt[:unicode]
			userdomain = Rex::Text.to_unicode(userdomain)
		end
		OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmhash, userdomain)
	end

	# Create the LANMAN response
	def self.lm_response(arg, half = false)
		begin
			hash = arg[:lm_hash]
			chal = arg[:challenge]
		rescue
			raise ArgumentError
		end
		chal = BASE::pack_int64le(chal) if chal.is_a?(Integer)
		if half then size = 7 else  size = 21 end
		keys = gen_keys hash.ljust(size, "\0")
		apply_des(chal, keys).join
	end

	# Synonym of lm_response for old compatibility with lib/rex/proto/smb/crypt
	def self.lanman_des(password, challenge)		
		lm_response({
			:lm_hash => self.lm_hash(password),
			:challenge => challenge
		})
	end
      
	def self.ntlm_response(arg)
		hash = arg[:ntlm_hash]
		chal = arg[:challenge]
		chal = BASE::pack_int64le(chal) if chal.is_a?(::Integer)
		keys = gen_keys(hash.ljust(21, "\0"))
		apply_des(chal, keys).join
	end

	#synonym of ntlm_response for old compatibility with lib/rex/proto/smb/crypt
	def self.ntlm_md4(password, challenge)
		ntlm_response({
			:ntlm_hash =>  self.ntlm_hash(password), 
			:challenge => challenge
		})
	end

	def self.ntlmv2_response(arg, opt = {})
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
		
		key, chal = arg[:ntlmv2_hash], arg[:challenge]
		if not (key and chal)
			raise ArgumentError , 'ntlmv2_hash and challenge are mandatory'
		end
		
		chal = BASE::pack_int64le(chal) if chal.is_a?(::Integer)
		bb   = nil
		
		if opt[:nt_client_challenge]
			if opt[:nt_client_challenge].to_s.length <= 24
				raise ArgumentError,"nt_client_challenge is not in a correct format " 
			end
			bb = opt[:nt_client_challenge]
		else
			if not arg[:target_info]
				raise ArgumentError, "target_info is mandatory in this case"
			end

			ti = arg[:target_info]
			cc = opt[:client_challenge] || rand(CONST::MAX64)
			cc = BASE::pack_int64le(cc) if cc.is_a?(::Integer)

			ts = opt[:timestamp] || Time.now.to_i

			# Convert the unix timestamp to windows format
			#   epoch -> milsec from Jan 1, 1601
			ts = 10000000 * (ts + CONST::TIME_OFFSET)

			blob = BASE::Blob.new
			blob.timestamp = ts
			blob.challenge = cc
			blob.target_info = ti
		
			bb = blob.serialize
		end

		OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, key, chal + bb) + bb

	end
      
	def self.lmv2_response(arg, opt = {})
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
		key = arg[:ntlmv2_hash]
		chal = arg[:challenge]
        
		chal = BASE::pack_int64le(chal) if chal.is_a?(::Integer)
		cc   = opt[:client_challenge] || rand(CONST::MAX64)
		cc   = BASE::pack_int64le(cc) if cc.is_a?(::Integer)

		OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, key, chal + cc) + cc
	end
      
	def self.ntlm2_session(arg, opt = {})
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
		passwd_hash,chal = arg[:ntlm_hash],arg[:challenge]
		if not (passwd_hash and chal)
			raise RuntimeError, "ntlm_hash and challenge are required"
		end

		cc = opt[:client_challenge] || rand(CONST::MAX64)
		cc = BASE::pack_int64le(cc) if cc.is_a?(Integer)

		keys = gen_keys(passwd_hash.ljust(21, "\0"))
		session_hash = OpenSSL::Digest::MD5.digest(chal + cc)[0,8]
		response = apply_des(session_hash, keys).join
		[cc.ljust(24, "\0"), response]
	end

	#
	# Signing method added for metasploit project
	#
	
	# Used when only the LMv1 response is provided (i.e., with Win9x clients)
	def self.lmv1_user_session_key(pass, opt = {})
		if opt[:pass_is_hash]
			usk = pass[0,8]
		else
			usk = self.lm_hash(pass.upcase[0,7],true)
		end
		usk.ljust(16,"\x00")
	end
		
	# This variant is used when the client sends the NTLMv1 response
	def self.ntlmv1_user_session_key(pass, opt = {})
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

		if opt[:pass_is_hash]
			usk = pass
		else
			usk = self.ntlm_hash(pass)
		end
		OpenSSL::Digest::MD4.digest(usk)
	end

	# Used when NTLMv1 authentication is employed with NTLM2 session security
	def self.ntlm2_session_user_session_key(pass, srv_chall, cli_chall, opt = {})
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

		ntlm_key = self.ntlmv1_user_session_key(pass, opt )
		session_chal = srv_chall + cli_chall
		OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlm_key, session_chal)
	end

	# Used when the LMv2 response is sent
	def self.lmv2_user_session_key(user, pass, domain, srv_chall, cli_chall, opt = {})
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl

		ntlmv2_key = self.ntlmv2_hash(user, pass, domain, opt)
		hash1 = OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmv2_key, srv_chall + cli_chall)
		OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmv2_key, hash1)
	end

	# Used when the NTLMv2 response is sent
	class << self; alias_method :ntlmv2_user_session_key, :lmv2_user_session_key; end

	# Used when LanMan Key flag is set
	def self.lanman_session_key(pass, srvchall, opt = {})
		if opt[:pass_is_hash]
			halfhash = pass[0,8]
		else
			halfhash = lm_hash(pass.upcase[0,7],true)
		end
		plain = self.lm_response({
			:lm_hash => halfhash[0,7],
			:challenge => srvchall
		}, true )
		key = halfhash  + ["bdbdbdbdbdbd"].pack("H*")
        keys = self.gen_keys(key)
       	apply_des(plain, keys).join
	end

	def self.encrypt_sessionkey(session_key, user_session_key)
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
		cipher = OpenSSL::Cipher::Cipher.new('rc4')
		cipher.encrypt
		cipher.key = user_session_key
		cipher.update(session_key) 
	end

	def self.decrypt_sessionkey(encrypted_session_key, user_session_key)
		raise RuntimeError, "No OpenSSL support" if not @@loaded_openssl
		cipher = OpenSSL::Cipher::Cipher.new('rc4')
		cipher.decrypt
		cipher.key = user_session_key
		cipher.update(encrypted_session_key) 
	end

	def self.make_weak_sessionkey(session_key,key_size,lanman_key = false)
		case key_size
		when 40
			if lanman_key
				return session_key[0,5] + "\xe5\x38\xb0" 
			else
				return session_key[0,5] 
			end
		when 56
			if lanman_key
				return session_key[0,7]  + "\xa0"
			else
				return session_key[0,7]  
			end
		else #128 
			return session_key[0,16]
		end
	end

end
end
end
end