Red Hat Cup -MISC-Advertising for Marriage

convert -flip screenshot.png screensho1.png

Benpian combined with my previous blog https://www.cnblogs.com/qq3285862072/p/11869403.html want to reproduce heard can go here http://ctf.heikanet.com/

0x00 find ???? God horse

Find a pineapple upside-down with gmip, screenshots export, use convert upside down. Get hint: ???? results b1cx

b1cxneedmoneyandgirlfirend the topic and people did not sit real evidence girlfriend, girlfriend dare wrong

convert installation

apt-get install imagemagick

More convert reference http://www.charry.org/docs/linux/ImageMagick/ImageMagick.html

Screenshot refer directly gmip Screenshot Export https://zh.wikihow.com/%E5%9C%A8Linux%E7%B3%BB%E7%BB%9F%E4%B8%AD%E6%88%AA%E5% B1% 8F

0x01 is what blinded your eyes

A dish. We look vegetable.png

Open failed, crc verification error, check the height of the net script blasting png (the windows can see pictures, find the picture is not quite right location, the right side there are some gaps, guess flag hidden in the picture correct height)

Installed 010editor, the official website to download directly extracting installer (This assumes you are already familiar with png hex file header format, Baidu)

# -*- coding: utf-8 -*-
import binascii
import struct
 
#\x49\x48\x44\x52\x00\x00\x01\x1F\x00\x00\x01\xA4\x08\x06\x00\x00\x00
 
crc32key = 0xB80A1736
for i in range(0, 65535):
    height = struct.pack('>i', i)
    data = '\x49\x48\x44\x52\x00\x00\x01\x1F' + height + '\x08\x06\x00\x00\x00'
 
    crc32result = binascii.crc32(data) & 0xffffffff
 
    if crc32result == crc32key:
        print''.join(map(lambda c: "%02X" % ord(c), height))

CAO refer to someone else's writeup https://blog.csdn.net/zjjcxy_long/article/details/103042786

Hidden write about lsb

Tools cloacked-pixel

python2 lsb.py extract vegetable.png  1.txt b1cxneedmoneyandgirlfirend

usage: lsb.py extract <stego_file> <out_file> <password>得到

VmlyZ2luaWEgY2lwaGVydGV4dDpnbnh0bXdnN3IxNDE3cHNlZGJzNjI1ODdoMA==

base64

Virginia ciphertext:gnxtmwg7r1417psedbs62587h0

Vigenere解密 keyword=b1cxneedmoneyandgirlfirend

of course

flagisdfbfafbfe

Submission Failed

I. . . . This site should be used (but in reality I was too anxious to understand is not in place, vegetable)

Key keyword is not digital. . . = Bcxneedmoneyandgirlfirend

flagisd7f1417bfafbf62587e0

Red Hat Cup -MISC-Advertising for Marriage

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