예제 #1
0
파일: elgamal.py 프로젝트: aalviz2/pysecret
 def sign(self, x, lambada):
     """
     Sign the message x.
     """
     gamma = pow(self.alpha, lambada, self.p)
     delta = ((x - self.priv * gamma) * utils.inv_modulo(lambada, self.p - 1)) % (self.p - 1)
     return (gamma, delta)
예제 #2
0
    def __init__(self, p=None, q=None, a=None, b = None, n=None, nb_bits=4096):
        """Initializes the magic keys.
        """
        if p is None and q is None and a is None:
            # 1. Generates 'p' and 'q' prime numbers of lengths 'nb_bits' in a 
            # random fashion.
            if p is None and q is None: 
                p = random.getrandbits(nb_bits)
                q = random.getrandbits(nb_bits)
                while not utils.miller_rabin(p):
                    p = random.getrandbits(nb_bits)
                while not utils.miller_rabin(q):
                    q = random.getrandbits(nb_bits)

        if a is None and b is None and n is None:
            # 2. Generates 'a', 'b' and 'n' thanks to 'phi' and 'b'.
            n   = p * q
            phi = (p - 1) * (q - 1)
            if b is None:
                while True:
                    b = random.randint(2, phi - 1)
                    if utils.is_prime_together(b, phi):
                        break
            a  = utils.inv_modulo(b, phi)

        self.private = a
        self.public = b
        self.modulus = n
예제 #3
0
 def sign(self, x, lambada):
     """
     Sign the message x.
     """
     gamma = pow(self.alpha, lambada, self.p)
     delta = ((x - self.priv * gamma) *
              utils.inv_modulo(lambada, self.p - 1)) % (self.p - 1)
     return (gamma, delta)
예제 #4
0
    def sign(self, m, k):

        md5obj = hashlib.md5()
        md5obj.update(str(m))
        digest = md5obj.hexdigest()
        mhash = int(digest,16)
        
        r = pow(self.g, k, self.p)
        s = ((mhash - self.priv * r) * utils.inv_modulo(k, self.p - 1)) % (self.p - 1)
        return (r, s)
예제 #5
0
파일: afine.py 프로젝트: aalviz2/pysecret
def decrypt(cypher, cle):
    """
    Afine decryption
    """
    inv = utils.inv_modulo(cle[0], 26)
    return [(chr(((ord(i) - 65 - cle[1]) * inv) % 26 + 65)) for i in cypher]
예제 #6
0
 def decrypt(self, y):
     """
     Decrypt y.
     """
     return (y[1] * utils.inv_modulo(pow(y[0], self.priv, self.p),
                                     self.p)) % self.p
예제 #7
0
파일: elgamal.py 프로젝트: aalviz2/pysecret
 def decrypt(self, y):
     """
     Decrypt y.
     """
     return (y[1] * utils.inv_modulo(pow(y[0], self.priv, self.p), self.p)) % self.p
예제 #8
0
import time

if __name__ == '__main__':
    print("Factoring RSA modulus with weak prime factors\n")
    print("Loading RSA keys")
    rsa_obj = rsa.RSA(a=0,
                      b=16219340638145739814556409984455971733340322034588741,
                      n=19674270149491236515870218329564212980341362732018899)
    print(rsa_obj)

    print("Factoring the modulus...")
    start = time.time()
    factors = utils.factors_decomposition(rsa_obj.modulus)
    phi = (p - 1) * (q - 1)
    # guess what are p and q ?
    end = time.time()
    print("Factorisation done in {} seconds\n".format(end - start))
    print(str(rsa_obj.modulus) + " = " + \
                        " * ".join([str(i) for i in factors]) + \
                        " = n * q ")
    print("Phi =", phi, "= (n - 1) * (q -1)")
    private = utils.inv_modulo(rsa_obj.public, phi)
    print("Private key: {}\n".format(private))

    rsa_obj.private = private

    print('Submit this flag:')
    print(
        rsa_obj.decrypt_int(
            332795103438906336586762421178058977844889453787945))
예제 #9
0
def decrypt(cypher, cle):
    """
    Afine decryption
    """
    inv = utils.inv_modulo(cle[0], 26)
    return [(chr(((ord(i) - 65 - cle[1]) * inv) % 26 + 65)) for i in cypher]