metasploit-framework/lib/rex/machparsey/mach.rb

#!/usr/bin/env ruby

require 'rex/machparsey/machbase'
require 'rex/machparsey/exceptions'
require 'rex/image_source'

module Rex
module MachParsey


class Mach < MachBase
	attr_accessor :mach_header, :segments, :isource, :bits, :endian, :arch, :fat_offset

	def initialize(isource, offset = 0, fat = false)
		_parse_mach_header(isource, offset)
		if fat == true
			self.fat_offset = offset
		else
			self.fat_offset = 0
		end

		self.isource = isource
	end

	def _parse_mach_header(isource, offset)
		self.mach_header = MachHeader.new(isource.read(offset, MACH_HEADER_SIZE_64))
		bits = mach_header.bits
		endian = mach_header.endian
		ncmds = mach_header.ncmds

		if bits == BITS_32
			offset += MACH_HEADER_SIZE
		else
			offset += MACH_HEADER_SIZE_64
		end


		segments = []
		ncmds.times do
			load_command = LoadCommand.new(isource.read(offset, LOAD_COMMAND_SIZE), endian)

			case load_command.cmd
				when LC_SEGMENT
					segments << Segment.new(isource.read(offset, SEGMENT_COMMAND_SIZE), bits, endian)
				when LC_SEGMENT_64
					segments << Segment.new(isource.read(offset, SEGMENT_COMMAND_SIZE_64), bits, endian)
			end

			offset += load_command.cmdsize
		end

		self.mach_header = mach_header
		self.segments = segments	
		self.isource = isource
		self.bits = bits
		self.endian = endian

		return segments
	end

	def self.new_from_file(filename, disk_backed = false)

		file = ::File.open(filename, "rb")

		if disk_backed
			return self.new(ImageSource::Disk.new(file))
		else
			obj = new_from_string(file.read)
			file.close
			return obj
		end
	end

	def self.new_from_string(data)
		return self.new(ImageSource::Memory.new(data))
	end

	def ptr_64?
		mach_header.bits == BITS_64		
	end

	def ptr_32?
		ptr_64? == false
	end

	def ptr_s(vaddr)
		(ptr_32?) ? ("0x%.8x" % vaddr) : ("0x%.16x" % vaddr)
	end

	def read(offset, len)
		isource.read(fat_offset + offset, len)
	end

	def index(*args)
		isource.index(*args)
	end

	def close
		isource.close
	end

end

class Fat < FatBase
	attr_accessor :fat_header, :fat_archs, :machos, :isource
	
	def initialize(isource, offset = 0)
		self.fat_archs = []
		self.machos = []
		self.isource = isource
		self.fat_header = FatHeader.new(isource.read(offset, FAT_HEADER_SIZE))
			
		if !self.fat_header
			raise FatHeaderError, "Could not parse FAT header"
		end
		
		print "Detected " +  self.fat_header.nfat_arch.to_s +  " archs in binary.\n"

		offset += FAT_HEADER_SIZE
		
		self.fat_header.nfat_arch.times do
			fat_arch = FatArch.new(isource.read(offset, FAT_ARCH_SIZE), self.fat_header.endian)
			self.fat_archs << fat_arch
			self.machos << Mach.new(isource, fat_arch.offset, true) 
			offset += FAT_ARCH_SIZE
		end
		
		
	end
	
	#this is useful for debugging but we don't use it for anything.
	def _parse_fat_header(isource, offset)
		archs = []
		nfat_arch = self.fat_header.nfat_arch

		print "Number of archs in binary: " + nfat_arch.to_s + "\n"

		nfat_arch.times do
			arch = FatArch.new(isource.read(offset, FAT_ARCH_SIZE), self.endian)
		
			case arch.cpu_type

			when CPU_TYPE_I386
				print "i386\n"
			
			when CPU_TYPE_X86_64
				print "x86_64\n"
			
			when CPU_TYPE_ARM
				print "Arm\n"
			
			when CPU_TYPE_POWERPC
				print "Power PC\n"
			
			when CPU_TYPE_POWERPC64
				print "Power PC 64\n"
			end
		
			offset += FAT_ARCH_SIZE
		end
	end

	def self.new_from_file(filename, disk_backed = false)

		file = ::File.open(filename, "rb")

		if disk_backed
			return self.new(ImageSource::Disk.new(file))
		else
			obj = new_from_string(file.read)
			file.close
			return obj
		end
	end
	

	def self.new_from_string(data)
		return self.new(ImageSource::Memory.new(data))
	end

	def ptr_64?
		mach_header.bits == BITS_64		
	end

	def ptr_32?
		ptr_64? == false
	end

	def ptr_s(vaddr)
		(ptr_32?) ? ("0x%.8x" % vaddr) : ("0x%.16x" % vaddr)
	end

	def read(offset, len)
		isource.read(offset, len)
	end

	def index(*args)
		isource.index(*args)
	end

	def close
		isource.close
	end

end


end
end