Class: Rex::Post::Meterpreter::Packet

Inherits:
GroupTlv show all
Defined in:
lib/rex/post/meterpreter/packet.rb

Overview

The logical meterpreter packet class

Instance Attribute Summary collapse

Attributes inherited from GroupTlv

#tlvs

Attributes inherited from Tlv

#compress, #type, #value

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from GroupTlv

#add_tlv, #add_tlvs, #each, #each_tlv, #each_tlv_with_index, #each_with_index, #get_tlv, #get_tlv_value, #get_tlv_values, #get_tlvs, #has_tlv?, #reset

Methods inherited from Tlv

#inspect, #meta_type?, #type?, #value?

Constructor Details

#initialize(type = nil, method = nil) ⇒ Packet

Initializes the packet to the supplied packet type and method, if any. If the packet is a request, a request identifier is created.



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# File 'lib/rex/post/meterpreter/packet.rb', line 648

def initialize(type = nil, method = nil)
  super(type)

  if (method)
    self.method = method
  end

  self.created_at = ::Time.now

  # If it's a request, generate a random request identifier
  if ((type == PACKET_TYPE_REQUEST) ||
      (type == PACKET_TYPE_PLAIN_REQUEST))
    rid = ''

    32.times { |val| rid << rand(10).to_s }

    add_tlv(TLV_TYPE_REQUEST_ID, rid)
  end
end

Instance Attribute Details

#created_at ⇒ Object

Returns the value of attribute created_at.



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# File 'lib/rex/post/meterpreter/packet.rb', line 604

def created_at
  @created_at
end

Class Method Details

.create_request(method = nil) ⇒ Object

Creates a request with the supplied method.



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# File 'lib/rex/post/meterpreter/packet.rb', line 615

def Packet.create_request(method = nil)
  return Packet.new(PACKET_TYPE_REQUEST, method)
end

.create_response(request = nil) ⇒ Object

Creates a response to a request if one is provided.



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# File 'lib/rex/post/meterpreter/packet.rb', line 622

def Packet.create_response(request = nil)
  response_type = PACKET_TYPE_RESPONSE
  method = nil

  if (request)
    if (request.type?(PACKET_TYPE_PLAIN_REQUEST))
      response_type = PACKET_TYPE_PLAIN_RESPONSE
    end

    method = request.method
  end

  return Packet.new(response_type, method)
end

Instance Method Details

#from_r(bytes) ⇒ Object

Override the function that reads from a raw byte stream so that the XORing of data is included in the process prior to passing it on to the default functionality that can parse the TLV values.



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# File 'lib/rex/post/meterpreter/packet.rb', line 690

def from_r(bytes)
  xor_key = bytes[0,4].unpack('N')[0]
  super(xor_bytes(xor_key, bytes[4, bytes.length]))
end

#method ⇒ Object

Returns the value of the packet’s method TLV.



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# File 'lib/rex/post/meterpreter/packet.rb', line 743

def method
  return get_tlv_value(TLV_TYPE_METHOD)
end

#method=(method) ⇒ Object

Sets the packet’s method TLV to the method supplied.



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# File 'lib/rex/post/meterpreter/packet.rb', line 736

def method=(method)
  add_tlv(TLV_TYPE_METHOD, method, true)
end

#method?(method) ⇒ Boolean

Checks to see if the packet’s method is equal to the supplied method.

Returns:

  • (Boolean) 


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# File 'lib/rex/post/meterpreter/packet.rb', line 729

def method?(method)
  return (get_tlv_value(TLV_TYPE_METHOD) == method)
end

#response? ⇒ Boolean

Checks to see if the packet is a response.

Returns:

  • (Boolean) 


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# File 'lib/rex/post/meterpreter/packet.rb', line 715

def response?
  return ((self.type == PACKET_TYPE_RESPONSE) ||
          (self.type == PACKET_TYPE_PLAIN_RESPONSE))
end

#result ⇒ Object

Gets the value of the packet’s result TLV.



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# File 'lib/rex/post/meterpreter/packet.rb', line 765

def result
  return get_tlv_value(TLV_TYPE_RESULT)
end

#result=(result) ⇒ Object

Sets the packet’s result TLV.



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# File 'lib/rex/post/meterpreter/packet.rb', line 758

def result=(result)
  add_tlv(TLV_TYPE_RESULT, result, true)
end

#result?(result) ⇒ Boolean

Checks to see if the packet’s result value is equal to the supplied result.

Returns:

  • (Boolean) 


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# File 'lib/rex/post/meterpreter/packet.rb', line 751

def result?(result)
  return (get_tlv_value(TLV_TYPE_RESULT) == result)
end

#rid ⇒ Object

Gets the value of the packet’s request identifier TLV.



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# File 'lib/rex/post/meterpreter/packet.rb', line 772

def rid
  return get_tlv_value(TLV_TYPE_REQUEST_ID)
end

#to_r ⇒ Object

Override the function that creates the raw byte stream for sending so that it generates an XOR key, uses it to scramble the serialized TLV content, and then returns the key plus the scrambled data as the payload.



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# File 'lib/rex/post/meterpreter/packet.rb', line 674

def to_r
  raw = super
  xor_key = rand(254) + 1
  xor_key |= (rand(254) + 1) << 8
  xor_key |= (rand(254) + 1) << 16
  xor_key |= (rand(254) + 1) << 24
  result = [xor_key].pack('N') + xor_bytes(xor_key, raw)
  result
end

#xor_bytes(xor_key, bytes) ⇒ Object

Xor a set of bytes with a given DWORD xor key.



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# File 'lib/rex/post/meterpreter/packet.rb', line 698

def xor_bytes(xor_key, bytes)
  result = ''
  bytes.bytes.zip([xor_key].pack('V').bytes.cycle).each do |b|
    result << (b[0].ord ^ b[1].ord).chr
  end
  result
end