mimajingsai_3/sm4Drbg.py

143 lines
5.7 KiB
Python
Executable File

import secrets
import time
from gmssl.sm4 import CryptSM4, SM4_ENCRYPT # pylint: disable=e0401 # type: ignore
import binascii
class SM4_RNG:
def __init__(self, personalization_string: bytes = b"", nonce: bytes = b""):
self.keylen = 16
self.reseed_counter = 0
self.reseed_interval_in_counter = 1 << 30
self.reseed_interval_in_time = 6000
self.min_entropy_input_length = 32
self.max_ectropy_input_length = 1 << 35 - 1
self.seedlen = 32
self.outlen = 16
self.blocklen = 16
self.seed_material = b""
self.sm4 = CryptSM4()
self.SM4_RNG_Instantiate(personalization_string, nonce)
def SM4_RNG_Instantiate(
self, personalization_string: bytes = b"", nonce: bytes = b""
) -> None:
self.min_entropy = self.min_entropy_input_length
self.entropy_input = secrets.token_bytes(self.min_entropy)
self.seed_material = self.entropy_input + nonce + personalization_string
self.seed_material = self.SM4_df(self.seed_material, self.seedlen)
self.Key = b"\x00" * self.keylen
self.V = b"\x00" * self.blocklen
self.SM4_RNG_Update(self.seed_material, self.Key, self.V)
self.reseed_counter = 1
self.last_reseed_time = int(time.time())
def SM4_RNG_Update(self, seed_material: bytes, Key: bytes, V: bytes) -> None:
temp = b""
self.sm4.set_key(Key, SM4_ENCRYPT)
while len(temp) < self.seedlen:
V_int = (int.from_bytes(V, "big") + 1) % (1 << self.blocklen)
self.output_block = self.sm4.crypt_ecb(V_int.to_bytes(self.blocklen, "big"))
temp = temp + self.output_block
temp = temp[: self.seedlen]
temp = int.from_bytes(temp, "big") ^ int.from_bytes(seed_material, "big")
temp = temp.to_bytes(self.seedlen, "big")
self.Key = temp[: self.keylen]
self.V = temp[-self.blocklen :]
def SM4_df(self, input_string: bytes, number_of_bits_to_return: int) -> bytes:
L = len(input_string)
N = number_of_bits_to_return
S = L.to_bytes(4, "big") + N.to_bytes(4, "big") + input_string + b"\x80"
while len(S) % self.outlen != 0:
S = S + b"\x00"
temp = b""
i = 0
K = b"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F \
\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1A\x1B\x1C\x1D\x1E\x1F"[
: self.keylen
]
while len(temp) < self.keylen + self.outlen:
IV = i.to_bytes(4, "big") + b"\x00" * (self.outlen - 4)
temp = temp + self.CBC_MAC(K, (IV + S))
i = i + 1
K = temp[: self.keylen]
X = temp[self.keylen + 1 : self.keylen + self.outlen]
tmp = b""
self.sm4.set_key(K, SM4_ENCRYPT)
while len(tmp) < number_of_bits_to_return:
X = self.sm4.crypt_ecb(X)
tmp = tmp + X
requested_bits = tmp[:number_of_bits_to_return]
return requested_bits
def CBC_MAC(self, Key: bytes, data_to_MAC: bytes) -> bytes:
self.sm4.set_key(Key, SM4_ENCRYPT)
chaining_value = b"\x00" * self.outlen
n = len(data_to_MAC) // self.outlen
for i in range(n):
input_block = int.from_bytes(chaining_value, "big") ^ int.from_bytes(
data_to_MAC[i * self.outlen : (i + 1) * self.outlen], "big"
)
chaining_value = self.sm4.crypt_ecb(
input_block.to_bytes(self.outlen, "big")
)
chaining_value = chaining_value[: self.outlen]
output_block = chaining_value
return output_block
def SM4_RNG_Reseed(self, additional_input: bytes) -> None:
self.min_entropy = self.min_entropy_input_length
self.entropy_input = secrets.token_bytes(self.min_entropy)
self.seed_material = self.entropy_input + additional_input
self.seed_material = self.SM4_df(self.seed_material, self.seedlen)
self.SM4_RNG_Update(self.seed_material, self.Key, self.V)
self.reseed_counter = 1
self.last_reseed_time = int(time.time())
def SM4_RNG_Generate(self, requested_number_of_bits:int, additional_input: bytes = b"")->bytes:
length = requested_number_of_bits // 8
returned_bits = b""
if (
self.reseed_counter > self.reseed_interval_in_counter
or int(time.time()) - self.last_reseed_time > self.reseed_interval_in_time
):
self.SM4_RNG_Reseed(additional_input)
if additional_input != b"":
additional_input = self.SM4_df(additional_input, self.seedlen)
self.SM4_RNG_Update(additional_input, self.Key, self.V)
else:
additional_input = b"\x00" * self.seedlen
self.sm4.set_key(self.Key, SM4_ENCRYPT)
while len(returned_bits) < length:
V_int = int.from_bytes(self.V, "big") + 1 % (1 << self.blocklen)
self.V = V_int.to_bytes(self.blocklen, "big")
output_block = self.sm4.crypt_ecb(self.V)
returned_bits = returned_bits + output_block
self.SM4_RNG_Update(additional_input, self.Key, self.V)
self.reseed_counter += 1
return returned_bits[:length]
if __name__ == "__main__":
bit_len = int(input("Enter the length of the bit string to be generated(bit):"))
num = int(input("Enter the number of the bit string to be generated:"))
file_name = input("Enter the name of the saved file:")
start_time = time.time()
sm4Drbg = SM4_RNG()
with open(file_name, "w") as f:
for i in range(num):
hex_output = binascii.hexlify(sm4Drbg.SM4_RNG_Generate(bit_len)).decode()
f.write(hex_output + "\n")
end_time = time.time()
elapsed_time = end_time - start_time
print(f"Program took {elapsed_time} seconds to run.")