BUUCTF MISC ZIP

This question irritated, write out a separate
first posted two pictures, one would use

This is the first title to 68 compressed,

each compression bag only 4bytes size, so it is conceivable that crc blasting, write their own scripts are always killed, lazy found a script

 

import zipfile
import string
import binascii

def CrackCrc(crc):
    for i in dic: 
        for j in dic:
            for k in dic:
                for h in dic:
                    s = i + j + k + h
                    if crc == (binascii.crc32(s.encode())):
                        f.write(s)
                        return

def CrackZip():
        for i in range(0,68):
            file = 'out'+str(i)+'.zip'
            crc = zipfile.ZipFile(file,'r').getinfo('data.txt').CRC
            CrackCrc(crc)

dic = string.ascii_letters + string.digits + '+/='

f = open('out.txt','w')
CrackZip()
print("CRC32碰撞完成")
f.close

 

Then the resulting string of base64 encoding, decoding hexadecimal

so handy previous figures, see CF 90 73 we know that this is an incomplete rar, fill 526 172 21 1A 07 00 After storage decompression, get

this very skin, and finally got flag.txt results give me a look at this,
then look at the second map, there is a 74 between the header and bit crc mark, this one is fixed, but we 7A is now

7A will be changed to 74, extract

the CMT where is the real flag of