With this challenge, they gave us an encrypted png. After a bit of trial and error I realized all I had to do was
xor the first few bytes of the encrypted file with the standard header of a png. I just downloaded a sample file. Here is my
Which gave me the key:
ecrypted = open('sleeping.png','rb').read().decode('base64') png = open('sample.png','rb').read() key = "" for i in range(0,30): key += chr(ord(ecrypted[i]) ^ ord(png[i])) print key
python get_key.py WoAh_A_Key!?WoAh_A]?ey#?WoAh_?Here is my
Which gave me the image with the flag: View the original post here.
key = "WoAh_A_Key!?" encrypted = open('sleeping.png','rb').read().decode('base64') out = open('decrypted.png','wb') for i in range(0,len(encrypted)): decrypted = chr(ord(encrypted[i]) ^ (ord(key[i % len(key)]))) out.write(decrypted) out.close()