def comfact(cipher, publickey):
for c in cipher:
commonfactor = gcd(publickey.n, s2n(c))
if commonfactor > 1:
publickey.q = commonfactor
publickey.p = publickey.n // publickey.q
priv_key = PrivateKey(
int(publickey.p),
int(publickey.q),
int(publickey.e),
int(publickey.n),
)
return (priv_key, None)
def attack(attack_rsa_obj, publickey, cipher=[]):
"""Try an attack where the public key has a common factor with the ciphertext - sourcekris
"""
if cipher:
commonfactor = gcd(publickey.n, s2n(cipher))
if commonfactor > 1:
publickey.q = commonfactor
publickey.p = publickey.n // publickey.q
priv_key = PrivateKey(
int(publickey.p), int(publickey.q), int(publickey.e), int(publickey.n)
)
return (priv_key, None)
return (None, None)