def __iadd__(self, other):
if type(other
) is GaloisFieldNumber and self.exponent == other.exponent:
self.encoding = gmpy2.mod(gmpy2.add(self.encoding, other.encoding),
self.gfp.p)
return self
else:
return self + other
def _batchgcd(xs):
tree = _product_tree(xs)
rems = tree.pop()
while tree:
LOGGER.info('Calculating batch GCDs: %10d' % (len(tree)))
xs = tree.pop()
rems = [
gmpy2.mod(rems[i // 2], gmpy2.mul(xs[i], xs[i]))
for i in range(len(xs))
]
return [gmpy2.gcd(gmpy2.t_div(r, n), n) for r, n in zip(rems, xs)]
def common_modulus_attack(modulus, exp1, exp2, msg1, msg2):
"""
Perform RSA Common Modulus Attack, given the modulus, two exponents
and two ciphertexts as integers.
Returns the plaintext as an integer.
"""
g, s, t = gmpy2.gcdext(exp1, exp2)
if g != 1:
print("Error: GCD of the two exponents is not 1!")
exit(1)
tmp1 = gmpy2.powmod(msg1, s, modulus)
tmp2 = gmpy2.powmod(msg2, t, modulus)
return int(gmpy2.mod(tmp1 * tmp2, modulus))
def __add__(self, other):
if type(other) in [int, float]:
return self + GaloisFieldNumber.encode(other, gfp=self.gfp)
elif type(other) is GaloisFieldNumber:
if self.exponent == other.exponent:
return GaloisFieldNumber(gmpy2.mod(
gmpy2.add(self.encoding, other.encoding), self.gfp.p),
exponent=self.exponent,
gfp=self.gfp)
elif self.exponent > other.exponent:
return self.decrease_exponent_to(other.exponent) + other
else:
return other.decrease_exponent_to(self.exponent) + self
else:
raise NotImplementedError
def encode(cls, scalar, gfp: GaloisFieldParams, exponent=FULL_PRECISION):
int_rep = round(scalar * cls.BASE**-exponent)
return GaloisFieldNumber(gmpy2.mod(int_rep, gfp.p),
exponent=exponent,
gfp=gfp)