【BUUCTF】MISC zip

import zipfile
import string
import binascii
 
def CrackCrc(crc):
    for i in dic:
        for j in dic:
            for p in dic:
                for q in dic:
                    s = i + j + p + q
                    if crc == (binascii.crc32(s.encode())):
                        #print s
                        f.write(s)
                        return
 
def CrackZip():
    for I in range(68):
        file = 'out' + str(I) + '.zip'
        f = zipfile.ZipFile(file, 'r')
        GetCrc = f.getinfo('data.txt')
        crc = GetCrc.CRC
        #以上3行爲獲取壓縮包CRC32值的步驟
        print (hex(crc))
        CrackCrc(crc)
 
dic = string.ascii_letters + string.digits + '+/='
 
f = open('out.txt', 'w')
CrackZip()
f.close()

跑出的數據

0x75f90d3a
0xbb21560
0x9b0d08f1
0x9b0d08f1
0x30fa0c4d
0xbaab6848
0xc2a03377
0x9b0d08f1
0x56c367d7
0x8881454e
0xf399b503
0x8a39ea8d
0xf8522b5f
0x22e2c069
0x9b0d08f1
0xabc2f082
0x1b10de7b
0x4246c91b
0x5a277153
0xe54efe07
0x65e4ea0a
0xdb4eed2e
0xac675758
0x3c84028a

RAR 文件頭：526172211A0700
RAR 文件尾：C43D7B00400700

改文件頭之後

在註釋裏

flag{nev3r_enc0de_t00_sm4ll_fil3_w1th_zip}