90 lines
1.4 KiB
Ruby
90 lines
1.4 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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#
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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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if (Rex::FileUtils.find_full_path('nasm') == nil)
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raise RuntimeError, "No nasm installation was found."
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end
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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)
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check
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# Open the temporary file
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tmp = Tempfile.new('nasm').path
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file = File.new(tmp, "w")
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# Write the assembly data to a file
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begin
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file.write("BITS 32\n" + assembly)
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file.close
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file = nil
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ensure
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file.close if (file)
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end
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# Run nasm
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if (system("nasm -f bin -o #{tmp}.out #{tmp}") == 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.readlines(tmp + ".out").join('')
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# Remove temporary files
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File.unlink(tmp)
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File.unlink(tmp + ".out")
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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)
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check
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# Race condition?! You bet!
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tmp = Tempfile.new('nasmout').path
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File.open(tmp, "wb") { |f| f.write(raw) }
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p = ::IO.popen("ndisasm -u #{tmp}")
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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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File.unlink(tmp)
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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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