近期初学安卓安全方向，学习到一个安卓伪加密技术，记录到博客。
安卓apk文件修改后缀，改为zip文件，打开发现是压缩包是加密的
我们使用16进制查看该zip包文件
搜索16进制数值50 4B 01 02并仔细寻找后面第五个字节为01的值
第五个字节为01时，文件的加密标志设置为ture，第五个字节为00时,加密标志设置为false,也就是表示不加密
我们将该16进制值01改为00并保存，即可正常打开zip压缩包
附上GitHub伪加密解密脚本1
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38#!/usr/bin/env python
# Copyright (C) 2013 thuxnder <patrick@bluebox.com>
#
# Licensed under the Apache License, Version 2.0 (the 'License');
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an 'AS IS' BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import argparse
from zipfile import ZipFile, ZipInfo
class ApkFile(ZipFile):
def extract(self, member, path=None, pwd=None):
if not isinstance(member, ZipInfo):
member = self.getinfo(member)
member.flag_bits ^= member.flag_bits%2
ZipFile.extract(self, member, path, pwd)
print 'extracting %s' % member.filename
def extractall(self, path=None, members=None, pwd=None):
map(lambda entry: self.extract(entry, path, pwd), members if members is not None and len(members)>0 else self.filelist)
if __name__ == '__main__':
parser = argparse.ArgumentParser(description='unpacks an APK that contains files which are wrongly marked as encrypted')
parser.add_argument('apk', type=str)
parser.add_argument('file', type=str, nargs='*')
args = parser.parse_args()
apk = ApkFile(args.apk,'r')
apk.extractall(members=args.file)
脚本原地址
https://github.com/adamely/DalvikBytecodeTampering/blob/master/unpack.py
