读取.dex文件中的所有字符串

import struct
import os
#这里定义一个读取字符串长度的函数
def DecUnsignedLEB128(file):
    result = struct.unpack("i", file.read(4))[0]#读取4字节中的第一个字节
    result = result&0x000000ff
    file.seek(-3, 1) #倒退回前面的第三个字节  # 不能直接从1字节强转为4字节，所以先取4字节，再清空3字节
    if (result > 0x7f):
        next = struct.unpack("i", file.read(4))[0]
        next = next&0x000000ff #第一位是个位
        file.seek(-3, 1)
        result = (result&0x7f) | (next&0x7f)<<7
        if(next > 0x7f):
            next = struct.unpack("i", file.read(4))[0]
            next = next&0x000000ff  #加入十位
            file.seek(-3, 1)
            result = result | (next&0x7f)<<14
            if(next > 0x7f):
                next = struct.unpack("i", file.read(4))[0]
                next = next&0x000000ff
                file.seek(-3, 1)
                result = result | (next&0x7f)<<21
                if(next > 0x7f):
                    next = struct.unpack("i", file.read(4))[0]
                    next = next&0x000000ff
                    file.seek(-3, 1)
                    result = result | next<<28

    #print "result:", result
    return result

dex = open("imissTest.dex", 'rb')   #rb的意思是 read and write in binary file
dex.seek(0x38, 0)#string table的偏移
tmp = dex.read(8)
string_count, string_table_off = struct.unpack("II", tmp)  #"II"是分别读取的意思
print ("size:", string_count, " off:", string_table_off)
dex.seek(string_table_off, 0)
DexStrOffList = []
count = 0
while(count<string_count):
    DexStrOffList.append(struct.unpack("i", dex.read(4))[0])#unpack返回一个tuple 取第0个元素
    count+=1
DexStrList = []
nonullcount = 0
for stroff in DexStrOffList:
    dex.seek(stroff, 0)
    strlen = DecUnsignedLEB128(dex)
    if(strlen == 0):
        continue
    input = dex.read(strlen)
    DexStrList.append(struct.unpack(str(strlen)+"s", input)) #解析不定长的字符串
    nonullcount+=1
outputfile = open("string.txt", "w")
count = 0
print ("string:",string_count)

for i in DexStrList:
    outputfile.write('%s\n'%i) #将元组中的元素写入文件
outputfile.close()
dex.close()