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99import logging
import shutil
import utils
from error import *
from strategy.decoderStrategy import DecoderStrategy
CALL_INST = ('CALL',)
FUNC_END = ('RET','RETN','RETF')
JUMP_INST = ('JMP','JZ','JNZ')
JCC_INST = ('JZ','JNZ')
class RecursiveDescent(DecoderStrategy):
addressDefer = None
def __init__(self, *args, **kwargs):
super(RecursiveDescent, self).__init__(*args, **kwargs)
self.addressDefer = []
def decode(self, continueOnError=True, verbose=False, detail=False):
if not verbose:
utils.logger.setLevel(logging.INFO)
else:
utils.logger.setLevel(logging.DEBUG)
terminalSize = shutil.get_terminal_size((80, 20))
instCount = 1
while not self.decoder.state.isRecursiveDescentComplete():
try:
if verbose:
title = "Instruction %d" % instCount
utils.logger.debug(utils.colors.INVERT+(title + " "*(terminalSize.columns-len(title)))+utils.colors.NORMAL)
operator, targetAddr = self.decoder.decodeSingleInstruction()
instCount += 1
if verbose:
self.decoder.state.showDecodeProgress(detail)
self.decoder.state.doRecursiveDescent(operator, targetAddr)
except InvalidTranslationValue:
location = self.decoder.state.getCurIdx()
try:
location = hex(location)
except:
location = repr(location)
try:
theByte = hex(self.decoder.state.contents[self.decoder.state.getCurIdx()])
except:
theByte = repr("???")
message = 'Unable to parse byte as an operand @ position %s (byte:%s).' % (location, theByte)
utils.logger.info(utils.colors.RED+utils.colors.BOLD +message+utils.colors.NORMAL)
self.decoder.state.markError()
if not continueOnError:
break
except InvalidOpcode:
location = self.decoder.state.getCurIdx()
try:
location = hex(location)
except:
location = repr(location)
try:
theByte = hex(self.decoder.state.contents[self.decoder.state.getCurIdx()])
except:
theByte = repr("???")
message = 'Unable to parse byte as an opcode @ position %s (byte:%s).' % (location, theByte)
utils.logger.info(utils.colors.RED+utils.colors.BOLD +message+utils.colors.NORMAL)
self.decoder.state.markError()
if not continueOnError:
break
except:
location = self.decoder.state.getCurIdx()
try:
location = hex(location)
except:
location = repr(location)
try:
theByte = hex(self.decoder.state.contents[self.decoder.state.getCurIdx()])
except:
theByte = repr("???")
message = 'Unrecoverable Error: Unable to parse byte @ position %s (byte:%s).' % (location, theByte)
utils.logger.info(utils.colors.RED+utils.colors.BOLD +message+utils.colors.NORMAL)
break
return self.decoder.state.isComplete()