Gemastik 2019 Final - Crypto

from Crypto.Cipher import AES
import sys
import os

key = os.urandom(16)
iv = os.urandom(16)
msg = "-isi pesan member TWICE-deomkicer"
msg = "A"*32
i = 0

class Unbuffered(object):
    def __init__(self, stream):
        self.stream = stream

    def write(self, data):
        self.stream.write(data)
        self.stream.flush()

    def writelines(self, datas):
        self.stream.writelines(datas)
        self.stream.flush()

    def __getattr__(self, attr):
        return getattr(self.stream, attr)

sys.stdout = Unbuffered(sys.stdout)

def pad(msg, v):
    if len(msg) % 16 != 0:
        msg = msg + str(v + 5) * ((16 - len(msg) % 16) - 1)
    else:
        msg = pad(msg + str(v + 5), v)
    return msg

def cpadding():
    padding = os.urandom(16)
    return padding

def encryptSenang_senang(iv, key, plain, v):
    cipher = AES.new(key, AES.MODE_CBC, iv)
    print plain + str(v)
    return (iv + cipher.encrypt(plain + str(v))).encode('hex')

print """
    Selamat datang di Gemastik 12
    Selamat bersenang-senang!
    (https://min4tozaki.me)
    Jangan aneh-aneh ya
"""

print "Senang-senang v" + str(i), ":"
print encryptSenang_senang(iv, key, pad(msg, i), i)
i += 1

while 1:
    print """
        Menu:
        1. Tebak Senang-senang v0
        2. Senang-senang v""" + str(i) + """
        3. Keluar
    """
    p = raw_input('Pilih : ')
    if p == '1':
        flag_f = raw_input("Input Senang-senang v0 : ")
        try:
            if flag_f == msg:
                print '\nSelamat!!!'
                print 'flag : gemastik12{' + msg +'}'
                exit(1)
            else:
                print 'S4d :('
        except:
            exit(1)
    elif p == '2':
        new_msg = raw_input("Enkrip Senang-senang v"+ str(i) +" : ")
        try:
            print "\nSenang-senang v" + str(i), ":"
            print encryptSenang_senang(iv, key, pad(new_msg, i), i)
            i += 1
        except:
            exit(1)
    elif p == '3':
        exit(1)
    else:
        exit(1)

blocks = []
while c:
    blocks.append(c[:32])
    c = c[32:]
print blocks

inter = []
for i in blocks:
    inter.append(xors('A'*16, i.decode('hex')))
print inter

def xors(a, b):
    res = ''
    for i in range(len(a)):
        res += chr(ord(a[i]) ^ ord(b[i % len(b)]))
    return res

def getiv(enc):
    iv = enc[32:64]
    enc = enc[96:]
    pesan = enc[:-32]
    return iv, pesan

enc = '8c6cde6fec14f9672d1d7bfa19be5055dbdbe6291d392102c7ef4ff595963e61345de9a61128cdbc4d6af5cfb707e4ea175d8985cc0eaa7ba6580182d8fd016bed45c0842c36f947b657239b1c4028ee323f4e87754f0eb077f2677afa46951f815c07f9857c89ee7d093a8ff58c00b5'
iv, pesan = getiv(enc)
c = iv+pesan

blocks = []
while c:
    blocks.append(c[:32])
    c = c[32:]
print blocks

inter = []
for i in blocks:
    inter.append(xors('A'*16, i.decode('hex')))
print inter

enc = '1d70da1eadb566202f9e6cc4cc30cab4dbdbe6291d392102c7ef4ff595963e6116e40aad380ed4ad62ac2cdad15fd3fc6259fd9bbd298965d37517f7e0891f47986fc49a0032e760b2252e8568715acc424a43f3013b7ac40386130ef945961ee07c825a525ffb06259bfd3dca768ba5'
iv, pesan = getiv(enc)
c = iv+pesan

blocks = []
while c:
    blocks.append(c[:32])
    c = c[32:]
print blocks

flag = []
for i in range(len(inter)):
    flag.append(xors(blocks[i].decode('hex'), inter[i]))
print flag