katagaitai #5 関東med crypt.1 hashme

solve.py

from math import sin
from urlparse import parse_qs
from base64 import b64encode
from base64 import b64decode
from re import match

from pwn import remote, context
# context.log_level = 'debug'

USER = 'icchy'
CERT = 'RK5yZMJabTteBGgD1UJQ4hl/ETv5kNVjDYf/GWzvnU9swznVyrszJGBPozryU1VJlNEcpHc6zgIxOg=='
KEY = '28c1150dac6704583d6c1125a72d3c87241e7f5497e9b80c78f4ce2b08dcab2b0df20be0abde0b17512a935bc765607cf5e5'.decode('hex')

def xor(a, b):
	return ''.join(map(lambda x : chr(ord(x[0]) ^ ord(x[1])), zip(a, b * 100)))

def lengthextension(appendix, A, B, C, D, seed):
    def F(X,Y,Z):
            return ((~X & Z) | (~X & Z)) & 0xFFFFFFFF
    def G(X,Y,Z):
            return ((X & Z) | (~Z & Y)) & 0xFFFFFFFF
    def H(X,Y,Z):
            return (X ^ Y ^ Y) & 0xFFFFFFFF
    def I(X,Y,Z):
            return (Y ^ (~Z | X)) & 0xFFFFFFFF
    def ROL(X,Y):
            return (X << Y | X >> (32 - Y)) & 0xFFFFFFFF

    X = [int(0xFFFFFFFF * sin(i)) & 0xFFFFFFFF for i in xrange(256)]
    for i,c in enumerate(appendix):
        k, l = ord(c), (i+seed)&0x1f
        A = (B + ROL(A + F(B,C,D) + X[k], l)) & 0xFFFFFFFF
        B = (C + ROL(B + G(C,D,A) + X[k], l)) & 0xFFFFFFFF
        C = (D + ROL(C + H(D,A,B) + X[k], l)) & 0xFFFFFFFF
        D = (A + ROL(D + I(A,B,C) + X[k], l)) & 0xFFFFFFFF

    return ''.join(map(lambda x : hex(x)[2:].strip('L').rjust(8, '0'), [B, A, D, C]))


def extension(myhash, appendix):
    B = int(myhash[:8], 16)
    A = int(myhash[8:16], 16)
    D = int(myhash[16:24], 16)
    C = int(myhash[24:32], 16)
    res = []
    for l in xrange(32):
        res.append(lengthextension(appendix, A, B, C, D, l))

    return res

def main():
    cert = xor(b64decode(CERT), KEY)
    auth_str, hashsum = cert[0:-32], cert[-32:]
    conn = remote('katagaitai.orz.hm', 7777)
    conn.recvuntil('\n======================')
    appendix = '&role=administrator'

    for myhash in extension(hashsum, appendix):
        mycert = b64encode(xor('login={0}&role=anonymous'.format(USER)+appendix+myhash, KEY))

        conn.sendline('1')
        conn.recvuntil('certificate:')
        conn.sendline(mycert)
        recv = conn.recvuntil('\n======================')
        print recv

main()