/
diffie_hellman.py
39 lines (30 loc) · 1.05 KB
/
diffie_hellman.py
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from math import sqrt, ceil, gcd
from sympy.ntheory import is_primitive_root, generate
from secrets import randbits
class Diffie(object):
def __init__(self, key_size, secret, key=0):
self.key_size = key_size
self.sys_seed = randbits(key_size)
if key==0:
self.generate_public_secret()
else:
self.prime = key[0]
self.g = key[1]
self.secret = secret
def get_common(self):
return (self.prime, self.g)
def generate_prime(self):
self.prime = generate.nextprime(self.sys_seed)
def generate_public_secret(self):
self.generate_prime()
self.find_prime_root_mod()
return self.prime, self.g
def find_prime_root_mod(self):
for x in range(2,self.prime):
if is_primitive_root(x,self.prime):
self.g = x
break
def compute_shared(self):
return pow(self.g, self.secret, self.prime)
def get_shared_secret(self, shared):
return pow(shared, self.secret, self.prime)