# https://c9x.me/x86/html/file_module_x86_id_219.html
def or_inst(state, inst):
    parts = inst.split(' ')
    op = parts[0]
    lhs = parts[1][:-1]
    rhs = parts[2]
    """Performs a bitwise inclusive OR operation between the destination (first) and source (second) 
	operands and stores the result in the destination operand location. The source operand can be an 
	immediate, a register, or a memory location; the destination operand can be a register or a memory 
	location. (However, two memory operands cannot be used in one instruction.) Each bit of the result 
	of the OR instruction is set to 0 if both corresponding bits of the first and second operands are 0; 
	otherwise, each bit is set to 1. """
    """The OF and CF flags are cleared; the SF, ZF, and PF flags are set according to the result. The state of the AF flag is undefined."""
    return state


if __name__ == "__main__":
    test_cases = ['or eax, 0x8', 'or ebx, ecx', 'or eax, ebx']
    for test in test_cases:
        s = Solver()
        state = Registers()
        state.eax = 0x7
        state = or_inst(state, test)
        s.add(state.eax == 0x7)
        print("eax = 0x7, {}, eax == 0x7?".format(test))
        if s.check() == sat:
            print('Eax can be 0x7!')
            print(s.model())
        else:
            print("Eax can't be 0x7 :(")
Exemplo n.º 2
0
	except:
		new_val = old_val + int(rhs, 16)
	setattr(state, lhs, new_val)

	"""The OF, SF, ZF, AF, CF, and PF flags are set according to the result."""
	state.of = If(new_val < old_val, True, False)
	state.cf = If((((old_val >> 31) & 1)  ^ ((new_val >> 31) & 1)) == 1, True, False)
	zf_state = If(new_val == 0, True, False)
	state.zf = zf_state
	sf_state = If(new_val < 0, True, False)
	state.sf = sf_state
	state.eip += 1
	return state

if __name__ == "__main__":
	examples = ['add eax, 0x8', 'add esp, 0x4', 'add eax, ebx']
	for example in examples:
		s = Solver()
		regs = Registers()
		regs.eax = 0xf4
		
		regs = add(regs, example)
		
		
		s.add(regs.sf == False)
		print("eax == 0xf4, {}, sf == False?".format(example)) 		
		check = s.check()
		print(check)
		if check == sat:
			print("Model: {}".format(s.model()))