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#

# = net/ntlm.rb

#

# 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.

#

# 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,v 1.1 2006/10/05 01:36:52 koheik Exp $

#++

require 'base64'

require 'openssl'

require 'kconv'

require 'openssl/digest'

module Net  #:nodoc:

  module NTLM

    module VERSION #:nodoc:

      MAJOR = 0

      MINOR = 1

      TINY  = 1

      STRING = [MAJOR, MINOR, TINY].join('.')

    end

    SSP_SIGN = "NTLMSSP\0"

    BLOB_SIGN = 0x00000101

    LM_MAGIC = "KGS!@\#$%"

    TIME_OFFSET = 11644473600

    MAX64 = 0xffffffffffffffff

    FLAGS = {

      :UNICODE              => 0x00000001,

      :OEM                  => 0x00000002,

      :REQUEST_TARGET       => 0x00000004,

  #   :UNKNOWN              => 0x00000008,

      :SIGN                 => 0x00000010,

      :SEAL                 => 0x00000020,

  #   :UNKNOWN              => 0x00000040,

      :NETWARE              => 0x00000100,

      :NTLM                 => 0x00000200,

  #   :UNKNOWN              => 0x00000400,

  #   :UNKNOWN              => 0x00000800,

      :DOMAIN_SUPPLIED      => 0x00001000,

      :WORKSTATION_SUPPLIED => 0x00002000,

      :LOCAL_CALL           => 0x00004000,

      :ALWAYS_SIGN          => 0x00008000,

      :TARGET_TYPE_DOMAIN   => 0x00010000,

      :TARGET_INFO          => 0x00800000,

      :NTLM2_KEY            => 0x00080000,

      :KEY128               => 0x20000000,

      :KEY56                => 0x80000000

    }

    FLAG_KEYS = FLAGS.keys.sort{|a, b| FLAGS[a] <=> FLAGS[b] }

    DEFAULT_FLAGS = {

      :TYPE1 => FLAGS[:UNICODE] | FLAGS[:OEM] | FLAGS[:REQUEST_TARGET] | FLAGS[:NTLM] | FLAGS[:ALWAYS_SIGN] | FLAGS[:NTLM2_KEY],

      :TYPE2 => FLAGS[:UNICODE],

      :TYPE3 => FLAGS[:UNICODE] | FLAGS[:REQUEST_TARGET] | FLAGS[:NTLM] | FLAGS[:ALWAYS_SIGN] | FLAGS[:NTLM2_KEY]

    }

  # module functions

    class << self

      def decode_utf16le(str)

        Kconv.kconv(swap16(str), Kconv::ASCII, Kconv::UTF16)

      end

      def encode_utf16le(str)

        swap16(Kconv.kconv(str, Kconv::UTF16, Kconv::ASCII))

      end

      def pack_int64le(val)

          [val & 0x00000000ffffffff, val >> 32].pack("V2")

      end

      def swap16(str)

        str.unpack("v*").pack("n*")

      end

      def split7(str)

        s = str.dup

        until s.empty?

          (ret ||= []).push s.slice!(0, 7)

        end

        ret

      end

      def gen_keys(str)

        split7(str).map{ |str7| 

          bits = split7(str7.unpack("B*")[0]).inject('')\

            {|ret, tkn| ret += tkn + (tkn.gsub('1', '').size % 2).to_s }

          [bits].pack("B*")

        }

      end

      def apply_des(plain, keys)

        dec = OpenSSL::Cipher::DES.new

        keys.map {|k|

          dec.key = k

          dec.encrypt.update(plain)

        }

      end

      def lm_hash(password)

        keys = gen_keys password.upcase.ljust(14, "\0")

        apply_des(LM_MAGIC, keys).join

      end   

      def ntlm_hash(password, opt = {})

        pwd = password.dup

        unless opt[:unicode]

          pwd = encode_utf16le(pwd)

        end

        OpenSSL::Digest::MD4.digest pwd

      end

      def ntlmv2_hash(user, password, target, opt={})

        ntlmhash = ntlm_hash(password, opt)

        userdomain = (user + target).upcase

        unless opt[:unicode]

          userdomain = encode_utf16le(userdomain)

        end

        OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, ntlmhash, userdomain)

      end

      # responses

      def lm_response(arg)

        begin

          hash = arg[:lm_hash]

          chal = arg[:challenge]

        rescue

          raise ArgumentError

        end

        chal = NTL::pack_int64le(chal) if chal.is_a?(Integer)

        keys = gen_keys hash.ljust(21, "\0")

        apply_des(chal, keys).join

      end

      def ntlm_response(arg)

        hash = arg[:ntlm_hash]

        chal = arg[:challenge]

        chal = NTL::pack_int64le(chal) if chal.is_a?(Integer)

        keys = gen_keys hash.ljust(21, "\0")

        apply_des(chal, keys).join

      end

      def ntlmv2_response(arg, opt = {})

        begin

          key = arg[:ntlmv2_hash]

          chal = arg[:challenge]

          ti = arg[:target_info]

        rescue

          raise ArgumentError

        end

        chal = NTL::pack_int64le(chal) if chal.is_a?(Integer)

        if opt[:client_challenge]

          cc  = opt[:client_challenge]

        else

          cc = rand(MAX64)

        end

        cc = NTLM::pack_int64le(cc) if cc.is_a?(Integer)

        if opt[:timestamp]

          ts = opt[:timestamp]

        else

          ts = Time.now.to_i

        end

        # epoch -> milsec from Jan 1, 1601

        ts = 10000000 * (ts + TIME_OFFSET)

        blob = Blob.new

        blob.timestamp = ts

        blob.challenge = cc

        blob.target_info = ti

        bb = blob.serialize

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

      end

      def lmv2_response(arg, opt = {})

        key = arg[:ntlmv2_hash]

        chal = arg[:challenge]

        chal = NTLM::pack_int64le(chal) if chal.is_a?(Integer)

        if opt[:client_challenge]

          cc  = opt[:client_challenge]

        else

          cc = rand(MAX64)

        end

        cc = NTLM::pack_int64le(cc) if cc.is_a?(Integer)

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

      end

      def ntlm2_session(arg, opt = {})

        begin

          passwd_hash = arg[:ntlm_hash]

          chal = arg[:challenge]

        rescue

          raise ArgumentError

        end

        if opt[:client_challenge]

          cc  = opt[:client_challenge]

        else

          cc = rand(MAX64)

        end

        cc = NTLM::pack_int64le(cc) if cc.is_a?(Integer)

        keys = gen_keys passwd_hash.ljust(21, "\0")

        session_hash = OpenSSL::Digest::MD5.digest(chal + cc).slice(0, 8)

        response = apply_des(session_hash, keys).join

        [cc.ljust(24, "\0"), response]

      end

    end

    # base classes for primitives

    class Field

      attr_accessor :active, :value

      def initialize(opts)

        @value  = opts[:value]

        @active = opts[:active].nil? ? true : opts[:active]

      end

      def size

        @active ? @size : 0

      end

    end

    class String < Field

      def initialize(opts)

        super(opts)

        @size = opts[:size]

      end

      def parse(str, offset=0)

        if @active and str.size >= offset + @size

          @value = str[offset, @size]

          @size

        else

          0

        end

      end

      def serialize

        if @active

          @value

        else

          ""

        end

      end

      def value=(val)

        @value = val

        @size = @value.nil? ? 0 : @value.size

        @active = (@size > 0)

      end

    end

    class Int16LE < Field

      def initialize(opt)

        super(opt)

        @size = 2

      end

      def parse(str, offset=0)

        if @active and str.size >= offset + @size

          @value = str[offset, @size].unpack("v")[0]

          @size

        else

          0

        end

      end

      def serialize

        [@value].pack("v")

      end

    end

    class Int32LE < Field

      def initialize(opt)

        super(opt)

        @size = 4

      end

      def parse(str, offset=0)

        if @active and str.size >= offset + @size

          @value = str.slice(offset, @size).unpack("V")[0]

          @size

        else

          0

        end

      end

      def serialize

        [@value].pack("V") if @active

      end

    end

    class Int64LE < Field

      def initialize(opt)

        super(opt)

        @size = 8

      end

      def parse(str, offset=0)

        if @active and str.size >= offset + @size

          d, u = str.slice(offset, @size).unpack("V2")

          @value = (u * 0x100000000 + d)

          @size

        else

          0

        end

      end

      def serialize

        [@value & 0x00000000ffffffff, @value >> 32].pack("V2") if @active

      end

    end

    # base class of data structure

    class FieldSet

      class << FieldSet

        def define(&block)

          c = Class.new(self)

          def c.inherited(subclass)

            proto = @proto

            subclass.instance_eval {

              @proto = proto

            }

          end

          c.module_eval(&block)

          c

        end

        def string(name, opts)

          add_field(name, String, opts)

        end

        def int16LE(name, opts)

          add_field(name, Int16LE, opts)

        end

        def int32LE(name, opts)

          add_field(name, Int32LE, opts)

        end

        def int64LE(name, opts)

          add_field(name, Int64LE, opts)

        end

        def security_buffer(name, opts)

          add_field(name, SecurityBuffer, opts)

        end

        def prototypes

          @proto

        end

        def names

          @proto.map{|n, t, o| n}

        end

        def types

          @proto.map{|n, t, o| t}

        end

        def opts

          @proto.map{|n, t, o| o}

        end

        private

        def add_field(name, type, opts)

          (@proto ||= []).push [name, type, opts]

          define_accessor name

        end

        def define_accessor(name)

          module_eval(<<-End, __FILE__, __LINE__ + 1)

          def #{name}

            self['#{name}'].value

          end

          def #{name}=(val)

            self['#{name}'].value = val

          end

          End

        end 

      end

      def initialize

        @alist = self.class.prototypes.map{ |n, t, o| [n, t.new(o)] }

      end

      def serialize

        @alist.map{|n, f| f.serialize }.join

      end

      def parse(str, offset=0)

        @alist.inject(offset){|cur, a|  cur += a[1].parse(str, cur)}

      end

      def size

        @alist.inject(0){|sum, a| sum += a[1].size}

      end

      def [](name)

        a = @alist.assoc(name.to_s.intern)

        raise ArgumentError, "no such field: #{name}" unless a

        a[1]

      end

      def []=(name, val)

        a = @alist.assoc(name.to_s.intern)

        raise ArgumentError, "no such field: #{name}" unless a

        a[1] = val

      end

      def enable(name)

        self[name].active = true

      end

      def disable(name)

        self[name].active = false

      end

    end

    Blob = FieldSet.define {

      int32LE    :blob_signature,   {:value => BLOB_SIGN}

      int32LE    :reserved,         {:value => 0}

      int64LE    :timestamp,      {:value => 0}

      string     :challenge,      {:value => "", :size => 8}

      int32LE    :unknown1,     {:value => 0}

      string     :target_info,      {:value => "", :size => 0}

      int32LE    :unknown2,         {:value => 0}

    }

    SecurityBuffer = FieldSet.define {

      int16LE   :length,        {:value => 0}

      int16LE   :allocated,     {:value => 0}

      int32LE   :offset,        {:value => 0}

    }

    class SecurityBuffer

      attr_accessor :active

      def initialize(opts)

        super()

        @value  = opts[:value]

        @active = opts[:active].nil? ? true : opts[:active]

        @size = 8

      end

      def parse(str, offset=0)

        if @active and str.size >= offset + @size

          super(str, offset)

          @value = str[self.offset, self.length]

          @size

        else

          0

        end

      end

      def serialize

        super if @active

      end

      def value

        @value

      end

      def value=(val)

        @value = val

        self.length = self.allocated = val.size

      end

      def data_size

        @active ? @value.size : 0

      end

    end

    class Message < FieldSet

      class << Message

        def parse(str)

          m = Type0.new

          m.parse(str)

          case m.type

          when 1

            t = Type1.parse(str)

          when 2

            t = Type2.parse(str)

          when 3

            t = Type3.parse(str)

          else

            raise ArgumentError, "unknown type: #{m.type}"

          end

          t

        end

        def decode64(str)

          parse(Base64.decode64(str))

        end

      end

      def has_flag?(flag)

        (self[:flag].value & FLAGS[flag]) == FLAGS[flag]

      end

      def set_flag(flag)

        self[:flag].value  |= FLAGS[flag]

      end

      def dump_flags

        FLAG_KEYS.each{ |k| print(k, "=", flag?(k), "\n") }

      end

      def serialize

        deflag

        super + security_buffers.map{|n, f| f.value}.join

      end

      def encode64

        Base64.encode64(serialize).gsub(/\n/, '')

      end

      def decode64(str)

        parse(Base64.decode64(str))

      end

      alias head_size size

      def data_size

        security_buffers.inject(0){|sum, a| sum += a[1].data_size}

      end

      def size

        head_size + data_size

      end

      private

      def security_buffers

        @alist.find_all{|n, f| f.instance_of?(SecurityBuffer)}

      end

      def deflag

        security_buffers.inject(head_size){|cur, a|

          a[1].offset = cur

          cur += a[1].data_size

        }

      end

      def data_edge

        security_buffers.map{ |n, f| f.active ? f.offset : size}.min

      end

      # sub class definitions

      Type0 = Message.define {

        string        :sign,      {:size => 8, :value => SSP_SIGN}

        int32LE       :type,      {:value => 0}

      }

      Type1 = Message.define {

        string          :sign,         {:size => 8, :value => SSP_SIGN}

        int32LE         :type,         {:value => 1}

        int32LE         :flag,         {:value => DEFAULT_FLAGS[:TYPE1] }

        security_buffer :domain,       {:value => "", :active => false}

        security_buffer :workstation,  {:value => "", :active => false}

        string          :padding,      {:size => 0, :value => "", :active => false }

      }

      class Type1

        class << Type1

          def parse(str)

            t = new

            t.parse(str)

            t

          end

        end

        def parse(str)

          super(str)

          enable(:domain) if has_flag?(:DOMAIN_SUPPLIED)

          enable(:workstation) if has_flag?(:WORKSTATION_SUPPLIED)

          super(str)

          if ( (len = data_edge - head_size) > 0)

            self.padding = "\0" * len

            super(str)

          end

        end

      end

      Type2 = Message.define{

        string        :sign,         {:size => 8, :value => SSP_SIGN}

        int32LE       :type,      {:value => 2}

        security_buffer   :target_name,  {:size => 0, :value => ""}

        int32LE       :flag,         {:value => DEFAULT_FLAGS[:TYPE2]}

        int64LE           :challenge,    {:value => 0}

        int64LE           :context,      {:value => 0, :active => false}

        security_buffer   :target_info,  {:value => "", :active => false}

        string        :padding,   {:size => 0, :value => "", :active => false }

      }

      class Type2

        class << Type2

          def parse(str)

            t = new

            t.parse(str)

            t

          end

        end

        def parse(str)

          super(str)

          if has_flag?(:TARGET_INFO)

            enable(:context)

            enable(:target_info)

            super(str)

          end

          if ( (len = data_edge - head_size) > 0)

            self.padding = "\0" * len

            super(str)

          end

        end

        def response(arg, opt = {})

          usr = arg[:user]

          pwd = arg[:password]

          if usr.nil? or pwd.nil?

            raise ArgumentError, "user and password have to be supplied"

          end

          if opt[:workstation]

            ws = opt[:workstation]

          else

            ws = ""

          end

          if opt[:client_challenge]

            cc  = opt[:client_challenge]

          else

            cc = rand(MAX64)

          end

          cc = NTLM::pack_int64le(cc) if cc.is_a?(Integer)

          opt[:client_challenge] = cc

          if has_flag?(:OEM) and opt[:unicode]

            usr = NTLM::decode_utf16le(usr)

            pwd = NTLM::decode_utf16le(pwd)

            ws  = NTLM::decode_utf16le(ws)

            opt[:unicode] = false

          end

          if has_flag?(:UNICODE) and !opt[:unicode]

            usr = NTLM::encode_utf16le(usr)

            pwd = NTLM::encode_utf16le(pwd)

            ws  = NTLM::encode_utf16le(ws)

            opt[:unicode] = true

          end

          tgt = self.target_name

          ti = self.target_info

          chal = self[:challenge].serialize

          if opt[:ntlmv2]

            ar = {:ntlmv2_hash => NTLM::ntlmv2_hash(usr, pwd, tgt, opt), :challenge => chal, :target_info => ti}

            lm_res = NTLM::lmv2_response(ar, opt)

            ntlm_res = NTLM::ntlmv2_response(ar, opt)

          elsif has_flag?(:NTLM2_KEY)

            ar = {:ntlm_hash => NTLM::ntlm_hash(pwd, opt), :challenge => chal}

            lm_res, ntlm_res = NTLM::ntlm2_session(ar, opt)

          else

            lm_res = NTLM::lm_response(pwd, chal)

            ntlm_res = NTLM::ntlm_response(pwd, chal)

          end

          Type3.create({

          	:lm_response => lm_res,

          	:ntlm_response => ntlm_res,

          	:domain => tgt,

            :user => usr,

            :workstation => ws,

            :flag => self.flag

          })

        end

      end

      Type3 = Message.define{

        string          :sign,          {:size => 8, :value => SSP_SIGN}

        int32LE         :type,          {:value => 3}

        security_buffer :lm_response,   {:value => ""}

        security_buffer :ntlm_response, {:value => ""}

        security_buffer :domain,        {:value => ""}

        security_buffer :user,          {:value => ""}

        security_buffer :workstation,   {:value => ""}

        security_buffer :session_key,   {:value => "", :active => false }

        int64LE         :flag,          {:value => 0, :active => false }

      }

      class Type3

        class << Type3

          def parse(str)

            t = new

            t.parse(str)

            t

          end

          def create(arg, opt ={})

            t = new

            t.lm_response = arg[:lm_response]

            t.ntlm_response = arg[:ntlm_response]

            t.domain = arg[:domain]

            t.user = arg[:user]

            t.workstation = arg[:workstation]

            if arg[:session_key]

              t.enable(:session_key)

              t.session_key = arg[session_key]

            end

            if arg[:flag]

              t.enable(:session_key)

              t.enable(:flag)

              t.flag = arg[:flag]

            end

            t

          end

        end

      end

    end

  end

end