Skip to content

Instantly share code, notes, and snippets.

/opcodes.py Secret

Created September 11, 2015 07:58
Show Gist options
  • Save anonymous/38729fd0be3865d1a78f to your computer and use it in GitHub Desktop.
Save anonymous/38729fd0be3865d1a78f to your computer and use it in GitHub Desktop.
"""1-byte opcode list grouped by octet.
So, pretty much http://www.sandpile.org/x86/opc_1.htm but worse!
Requires: capstone, colorama (windows), click
"""
import capstone
import click
engine = capstone.Cs(capstone.CS_ARCH_X86, capstone.CS_MODE_32)
line = click.style(''.join(['\txx%01o' % c for c in range(8)]), bold=1)
for c in range(256):
isn = list(engine.disasm(chr(c), 1))
if not c&7: # high octets
if line: click.echo(line)
line = click.style(' %02ox ' % (c >> 3), bold=1)
if len(isn) == 1: # 1-byte opcode found
txt = isn[0].mnemonic + ' ' + isn[0].op_str
if len(txt) >= 8: txt = isn[0].mnemonic
line += click.style(txt, fg='green')
elif len(isn) == 0: # check if it's a 2-byte opcode+arg
guesses = [list(engine.disasm(chr(c) + chr(d), 1)) for d in range(256)]
mnemonics = [g[0].mnemonic for g in guesses if len(g)>0]
if len(set(mnemonics)) == 1: # all mnemonics the same
line += click.style(mnemonics[0],
fg='yellow' if len(mnemonics) == 256 else 'red')
else: # couldn't disassemble a consistent opcode
line += '-'
line += '\t'
click.echo()
click.secho('\tno argument', fg='green')
click.secho('\thas argument', fg='yellow')
click.secho('\thas argument, couldn''t disasm some values', fg='red')
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment