Class: Rex::Proto::NTLM::Message

Inherits:
Base::FieldSet show all
Defined in:
lib/rex/proto/ntlm/message.rb

Constant Summary collapse

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

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base::FieldSet

#[], #[]=, define, #disable, #enable, #initialize, int16LE, int32LE, int64LE, names, opts, #parse, prototypes, security_buffer, string, types

Constructor Details

This class inherits a constructor from Rex::Proto::NTLM::Base::FieldSet

Class Method Details

.decode64(str) ⇒ Object


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# File 'lib/rex/proto/ntlm/message.rb', line 78

def decode64(str)
  parse(Rex::Text::decode_base64(str))
end

.downgrade_type_message(message) ⇒ Object

Downgrading Type messages to LMv1/NTLMv1 and removing signing


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# File 'lib/rex/proto/ntlm/message.rb', line 490

def self.downgrade_type_message(message)
  decode = Rex::Text.decode_base64(message.strip)

  type = decode[8,1].unpack("C").first

  if (type > 0 and type < 4)
    reqflags = decode[12..15] if (type == 1 or type == 3)
    reqflags = decode[20..23] if (type == 2)
    reqflags = reqflags.unpack("V")

    # Remove NEGOTIATE_NTLMV2_KEY and NEGOTIATE_ALWAYS_SIGN, this lowers the negotiation
    # down to LMv1/NTLMv1.
    if (reqflags & CONST::NEGOTIATE_NTLM2_KEY) == CONST::NEGOTIATE_NTLM2_KEY
      reqflags = reqflags - CONST::NEGOTIATE_NTLM2_KEY
    end
    if (reqflags & CONST::NEGOTIATE_ALWAYS_SIGN) == CONST::NEGOTIATE_ALWAYS_SIGN
      reqflags = reqflags - CONST::NEGOTIATE_ALWAYS_SIGN
    end

    # Return the flags back to the decode so we can base64 it again
    flags = reqflags.to_s(16)
    0.upto(8) do |idx|
      if (idx > flags.length)
        flags.insert(0, "0")
      end
    end

    idx = 0
    0.upto(3) do |cnt|
      if (type == 2)
        decode[23-cnt] = [flags[idx,1]].pack("C")
      else
        decode[15-cnt] = [flags[idx,1]].pack("C")
      end
      idx += 2
    end

  end
  return Rex::Text.encode_base64(decode).delete("\n") # base64 encode and remove the returns
end

.parse(str) ⇒ Object


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# File 'lib/rex/proto/ntlm/message.rb', line 62

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

.process_type1_message(message, nonce = "\x11\x22\x33\x44\x55\x66\x77\x88", win_domain = 'DOMAIN', win_name = 'SERVER', dns_name = 'server', dns_domain = 'example.com', downgrade = true) ⇒ Object

Process Type 1 NTLM Messages, return a Base64 Type 2 Message


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# File 'lib/rex/proto/ntlm/message.rb', line 400

def self.process_type1_message(message, nonce = "\x11\x22\x33\x44\x55\x66\x77\x88", win_domain = 'DOMAIN',
        win_name = 'SERVER', dns_name = 'server', dns_domain = 'example.com', downgrade = true)

  dns_name = Rex::Text.to_unicode(dns_name + "." + dns_domain)
  win_domain = Rex::Text.to_unicode(win_domain)
  dns_domain = Rex::Text.to_unicode(dns_domain)
  win_name = Rex::Text.to_unicode(win_name)
  decode = Rex::Text.decode_base64(message.strip)

  type = decode[8,1].unpack("C").first

  if (type == 1)
    # A type 1 message has been received, lets build a type 2 message response

    reqflags = decode[12,4]
    reqflags = reqflags.unpack("V").first

    if (reqflags & CONST::REQUEST_TARGET) == CONST::REQUEST_TARGET

      if (downgrade)
        # At this time NTLMv2 and signing requirements are not supported
        if (reqflags & CONST::NEGOTIATE_NTLM2_KEY) == CONST::NEGOTIATE_NTLM2_KEY
          reqflags = reqflags - CONST::NEGOTIATE_NTLM2_KEY
        end
        if (reqflags & CONST::NEGOTIATE_ALWAYS_SIGN) == CONST::NEGOTIATE_ALWAYS_SIGN
          reqflags = reqflags - CONST::NEGOTIATE_ALWAYS_SIGN
        end
      end

      flags = reqflags + CONST::TARGET_TYPE_DOMAIN + CONST::TARGET_TYPE_SERVER
      tid = true

      tidoffset = 48 + win_domain.length
      tidbuff =
        [2].pack('v') +				# tid type, win domain
        [win_domain.length].pack('v') +
        win_domain +
        [1].pack('v') +				# tid type, server name
        [win_name.length].pack('v') +
        win_name +
        [4].pack('v')	+			 # tid type, domain name
        [dns_domain.length].pack('v') +
        dns_domain +
        [3].pack('v')	+			# tid type, dns_name
        [dns_name.length].pack('v') +
        dns_name
    else
      flags = CONST::NEGOTIATE_UNICODE + CONST::NEGOTIATE_NTLM
      tid = false
    end

    type2msg = "NTLMSSP\0" + # protocol, 8 bytes
         "\x02\x00\x00\x00"		# type, 4 bytes

    if (tid)
      type2msg +=	# Target security info, 8 bytes. Filled if REQUEST_TARGET
      [win_domain.length].pack('v') +	 # Length, 2 bytes
      [win_domain.length].pack('v')	 # Allocated space, 2 bytes
    end

    type2msg +="\x30\x00\x00\x00" + #		Offset, 4 bytes
        [flags].pack('V') +	# flags, 4 bytes
        nonce +		# the nonce, 8 bytes
        "\x00" * 8		# Context (all 0s), 8 bytes

    if (tid)
      type2msg +=		# Target information security buffer. Filled if REQUEST_TARGET
        [tidbuff.length].pack('v') +	# Length, 2 bytes
        [tidbuff.length].pack('v') +	# Allocated space, 2 bytes
        [tidoffset].pack('V') +		# Offset, 4 bytes (usually \x48 + length of win_domain)
        win_domain +			# Target name data (domain in unicode if REQUEST_UNICODE)
                # Target information data
        tidbuff +			#	Type, 2 bytes
                #	Length, 2 bytes
                #	Data (in unicode if REQUEST_UNICODE)
        "\x00\x00\x00\x00"		# Terminator, 4 bytes, all \x00
    end

    type2msg = Rex::Text.encode_base64(type2msg).delete("\n") # base64 encode and remove the returns
  else
    # This is not a Type2 message
    type2msg = ""
  end

  return type2msg
end

.process_type3_message(message) ⇒ Object

Process Type 3 NTLM Message (in Base64)

from www.innovation.ch/personal/ronald/ntlm.html

struct { byte protocol; // 'N', 'T', 'L', 'M', 'S', 'S', 'P', '0' byte type; // 0x03 byte zero;

short lm_resp_len; // LanManager response length (always 0x18) short lm_resp_len; // LanManager response length (always 0x18) short lm_resp_off; // LanManager response offset byte zero;

short nt_resp_len; // NT response length (always 0x18) short nt_resp_len; // NT response length (always 0x18) short nt_resp_off; // NT response offset byte zero;

short dom_len; // domain string length short dom_len; // domain string length short dom_off; // domain string offset (always 0x40) byte zero;

short user_len; // username string length short user_len; // username string length short user_off; // username string offset byte zero;

short host_len; // host string length short host_len; // host string length short host_off; // host string offset byte zero;

short msg_len; // message length byte zero;

short flags; // 0x8201 byte zero;

byte dom; // domain string (unicode UTF-16LE) byte user; // username string (unicode UTF-16LE) byte host; // host string (unicode UTF-16LE) byte lm_resp; // LanManager response byte nt_resp; // NT response } type_3_message


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# File 'lib/rex/proto/ntlm/message.rb', line 365

def self.process_type3_message(message)
  decode = Rex::Text.decode_base64(message.strip)
  type = decode[8,1].unpack("C").first
  if (type == 3)
    lm_len = decode[12,2].unpack("v").first
    lm_offset = decode[16,2].unpack("v").first
    lm = decode[lm_offset, lm_len].unpack("H*").first

    nt_len = decode[20,2].unpack("v").first
    nt_offset = decode[24,2].unpack("v").first
    nt = decode[nt_offset, nt_len].unpack("H*").first

    dom_len = decode[28,2].unpack("v").first
    dom_offset = decode[32,2].unpack("v").first
    domain = decode[dom_offset, dom_len]

    user_len = decode[36,2].unpack("v").first
    user_offset = decode[40,2].unpack("v").first
    user = decode[user_offset, user_len]

    host_len = decode[44,2].unpack("v").first
    host_offset = decode[48,2].unpack("v").first
    host = decode[host_offset, host_len]

    return domain, user, host, lm, nt
  else
    return "", "", "", "", ""
  end
end

Instance Method Details

#data_sizeObject


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# File 'lib/rex/proto/ntlm/message.rb', line 110

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

#decode64(str) ⇒ Object


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# File 'lib/rex/proto/ntlm/message.rb', line 104

def decode64(str)
  parse(Rex::Text::decode_base64(str))
end

#dump_flagsObject


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# File 'lib/rex/proto/ntlm/message.rb', line 91

def dump_flags
  CONST::FLAG_KEYS.each{ |k| print(k, "=", flag?(k), "\n") }
end

#encode64Object


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# File 'lib/rex/proto/ntlm/message.rb', line 100

def encode64
  Rex::Text::encode_base64(serialize)
end

#has_flag?(flag) ⇒ Boolean

self

Returns:

  • (Boolean)

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# File 'lib/rex/proto/ntlm/message.rb', line 83

def has_flag?(flag)
  (self[:flag].value & CONST::FLAGS[flag]) == CONST::FLAGS[flag]
end

#head_sizeObject


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# File 'lib/rex/proto/ntlm/message.rb', line 108

alias head_size size

#serializeObject


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# File 'lib/rex/proto/ntlm/message.rb', line 95

def serialize
  deflag
  super + security_buffers.map{|n, f| f.value}.join
end

#set_flag(flag) ⇒ Object


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# File 'lib/rex/proto/ntlm/message.rb', line 87

def set_flag(flag)
  self[:flag].value  |= CONST::FLAGS[flag]
end

#sizeObject


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# File 'lib/rex/proto/ntlm/message.rb', line 114

def size
  head_size + data_size
end