def generate(pwd, stat):
config.generate_r()
pwd = mpz(crypt.get_bit_str_from_byte(pwd), base=2)
global table
table = [] # clear the table
for i in xrange(config.max_features):
x_0 = crypt.p(mpz((i + 1) << 1), config.r) # calculate x0, x1 and y0, y1
x_1 = crypt.p(mpz(((i + 1) << 1) + 1), config.r)
y_0 = gmpy2.add(poly.calculate(x_0), crypt.g(mpz((i + 1) << 1), config.r ^ pwd)) # use r xor pwd as the key
y_1 = gmpy2.add(poly.calculate(x_1), crypt.g(mpz(((i + 1) << 1) + 1), config.r ^ pwd))
if reader.if_init():
table.append((y_0, y_1)) # if in initialization phase, add correct value
else:
if stat[i][0] is None:
table.append((y_0, y_1)) # if no statistic information is derived
elif (stat[i][1] + stat[i][0] * config.k) < config.ti: # if fast
rand_value = gmpy2.t_mod(config.generate_rand(), config.q)
table.append((y_0, rand_value))
elif (stat[i][1] - stat[i][0] * config.k) > config.ti: # if slow
rand_value = gmpy2.t_mod(config.generate_rand(), config.q)
table.append((rand_value, y_1))
else:
table.append((y_0, y_1))
def generate_poly():
global c
c = [config.h_pwd] # first coefficient is the hardened password
for i in xrange(config.max_features - 1):
tmp = config.generate_rand()
c.append(gmpy2.t_mod(tmp, config.q))
message = message[AES.block_size:]
cipher = AES.new(key=get_byte_str_from_mpz(key), mode=AES.MODE_CFB, IV=iv)
return cipher.decrypt(message)
# a keyed pseudorandom function family
def g(x, key):
if not config.simple:
mac = HMAC.new(key=get_byte_str_from_mpz(key), msg=get_byte_str_from_mpz(x)).digest()
return gmpy2.t_mod(mpz(get_bit_str_from_byte(mac), base=2), config.q)
return mpz() # if in simple mode, return 0
# a keyed pseudorandom permutation function family
def p(x, key):
if not config.simple:
mac = HMAC.new(key=get_byte_str_from_mpz(key), msg=get_byte_str_from_mpz(x), digestmod=SHA).digest()
return gmpy2.t_mod(mpz(get_bit_str_from_byte(mac), base=2), config.q)
return x # if in simple mode, return x
if __name__ == "__main__":
# test for encrypt and decrypt
mock_history = "history1;history2;etc."
config.init_random()
for i in xrange(100):
mock_key = mpz(config.generate_rand())
history_encrypt = encrypt(mock_history, mock_key)
history_decrypt = decrypt(history_encrypt, mock_key)
assert mock_history == history_decrypt, "de/encryption failed!"
