105 lines
1.8 KiB
Ruby
105 lines
1.8 KiB
Ruby
#!/usr/bin/env ruby
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require 'tempfile'
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require 'rex/file'
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require 'rex/text'
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module Rex
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module Assembly
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###
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#
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# This class uses nasm to assemble and disassemble stuff.
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#
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###
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class Nasm
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@@nasm_path = 'nasm'
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@@ndisasm_path = 'ndisasm'
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#
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# Ensures that the nasm environment is sane.
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#
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def self.check
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@@nasm_path =
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Rex::FileUtils.find_full_path('nasm') ||
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Rex::FileUtils.find_full_path('nasm.exe') ||
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Rex::FileUtils.find_full_path('nasmw.exe') ||
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raise(RuntimeError, "No nasm installation was found.")
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@@ndisasm_path =
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Rex::FileUtils.find_full_path('ndisasm') ||
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Rex::FileUtils.find_full_path('ndisasm.exe') ||
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Rex::FileUtils.find_full_path('ndisasmw.exe') ||
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raise(RuntimeError, "No ndisasm installation was found.")
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end
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#
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# Assembles the supplied assembly and returns the raw opcodes.
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#
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def self.assemble(assembly, bits=32)
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check
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# Open the temporary file
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tmp = Tempfile.new('nasmXXXX')
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tmp.binmode
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tpath = tmp.path
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opath = tmp.path + '.out'
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# Write the assembly data to a file
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tmp.write("BITS #{bits}\n" + assembly)
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tmp.flush()
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tmp.seek(0)
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# Run nasm
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if (system(@@nasm_path, '-f', 'bin', '-o', opath, tpath) == false)
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raise RuntimeError, "Assembler did not complete successfully: #{$?.exitstatus}"
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end
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# Read the assembled text
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rv = ::IO.read(opath)
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# Remove temporary files
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File.unlink(opath)
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tmp.close(true)
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rv
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end
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#
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# Disassembles the supplied raw opcodes
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#
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def self.disassemble(raw, bits=32)
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check
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tmp = Tempfile.new('nasmout')
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tmp.binmode
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tfd = File.open(tmp.path, "wb")
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tfd.write(raw)
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tfd.flush()
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tfd.close
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p = ::IO.popen("\"#{@@ndisasm_path}\" -b #{bits} \"#{tmp.path}\"")
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o = ''
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begin
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until p.eof?
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o += p.read
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end
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ensure
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p.close
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end
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tmp.close(true)
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o
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end
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end
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end
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end
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