MCSC17_RSA.py

#usr/bin/python

#Faid Mohammed Amine 
#Fb : piratuer


#MCSC 2017 RSA 100pts

import gmpy
import binascii




def wood_func(n):
    return n*pow(2,n)-1


def bytes_from_file(filename, chunksize=8192):
    with open(filename, "rb") as f:
        while True:
            chunk = f.read(chunksize)
            if chunk:
                for b in chunk:
                    yield b
            else:
                break


def main(n):
    i = 100
    while(i<500):
        w = wood_func(i)
        p = n / w
        if((p * w) == n):
            q = w
            print "Found " + str(q)
            i = 500
        i += 1

    phi = (p-1)* (q-1)
    d = gmpy.invert(e,phi)
    c = ""
    for bt in bytes_from_file('encrypted_lladoow'):
        c += binascii.hexlify(bt)
    c = int(c,16)
    m = hex(pow(c,d,n))[2:]
    flag = m.decode('hex')

    
    return flag


if __name__ == "__main__":
    
    n = int(open("N").read().encode('hex'),16)
    e = int(open("E").read().encode('hex'),16)
    print main(n)