breathleas/gmssl-python

a python crypto for sm2/sm3/sm4/sm9

Original: https://github.com/duanhongyi/gmssl

Now include sm9.

GMSSL

GmSSL是一个开源的加密包的python实现，支持SM2/SM3/SM4/SM9等国密(国家商用密码)算法、项目采用对商业应用友好的类BSD开源许可证，开源且可以用于闭源的商业应用。

Setup and Test

export PYTHONPATH=/path/to/gmssl:$PYTHONPATH

Replace /path/to/gmssl with the path where gmssl is placed. Run:

python3 tests/test_sm2.py
python3 tests/test_sm3.py
python3 tests/test_sm4.py
python3 tests/test_sm9.py

Replace tests with the path into the tests directory.

SM2算法

RSA算法的危机在于其存在亚指数算法，对ECC算法而言一般没有亚指数攻击算法 SM2椭圆曲线公钥密码算法：我国自主知识产权的商用密码算法，是ECC（Elliptic Curve Cryptosystem）算法的一种，基于椭圆曲线离散对数问题，计算复杂度是指数级，求解难度较大，同等安全程度要求下，椭圆曲线密码较其他公钥算法所需密钥长度小很多。

gmssl是包含国密SM2算法的Python实现， 提供了 encrypt、 decrypt等函数用于加密解密， 用法如下：

1. 初始化CryptSM2

import base64
import binascii
from gmssl import sm2, func
#16进制的公钥和私钥
private_key = '00B9AB0B828FF68872F21A837FC303668428DEA11DCD1B24429D0C99E24EED83D5'
public_key = 'B9C9A6E04E9C91F7BA880429273747D7EF5DDEB0BB2FF6317EB00BEF331A83081A6994B8993F3F5D6EADDDB81872266C87C018FB4162F5AF347B483E24620207'
sm2_crypt = sm2.CryptSM2(
    public_key=public_key, private_key=private_key)

2. encrypt和decrypt

#数据和加密后数据为bytes类型
data = b"111"
enc_data = sm2_crypt.encrypt(data)
dec_data =sm2_crypt.decrypt(enc_data)
assert dec_data == data

3. sign和verify

data = b"111" # bytes类型
random_hex_str = func.random_hex(sm2_crypt.para_len)
sign = sm2_crypt.sign(data, random_hex_str) #  16进制
assert sm2_crypt.verify(sign, data) #  16进制

SM4算法

国密SM4(无线局域网SMS4)算法， 一个分组算法， 分组长度为128bit， 密钥长度为128bit， 算法具体内容参照SM4算法。

gmssl是包含国密SM4算法的Python实现， 提供了 encrypt_ecb、 decrypt_ecb、 encrypt_cbc、 decrypt_cbc等函数用于加密解密， 用法如下：

1. 初始化CryptSM4

from gmssl.sm4 import CryptSM4, SM4_ENCRYPT, SM4_DECRYPT

key = b'3l5butlj26hvv313'
value = b'111' #  bytes类型
iv = b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' #  bytes类型
crypt_sm4 = CryptSM4()

2. encrypt_ecb和decrypt_ecb

crypt_sm4.set_key(key, SM4_ENCRYPT)
encrypt_value = crypt_sm4.crypt_ecb(value) #  bytes类型
crypt_sm4.set_key(key, SM4_DECRYPT)
decrypt_value = crypt_sm4.crypt_ecb(encrypt_value) #  bytes类型
assert value == decrypt_value

3. encrypt_cbc和decrypt_cbc

crypt_sm4.set_key(key, SM4_ENCRYPT)
encrypt_value = crypt_sm4.crypt_cbc(iv , value) #  bytes类型
crypt_sm4.set_key(key, SM4_DECRYPT)
decrypt_value = crypt_sm4.crypt_cbc(iv , encrypt_value) #  bytes类型
assert value == decrypt_value

SM9算法

1. sign和verify

idA = 'A'
idB = 'B'
master_public, master_secret = sm9.setup ('sign')
Da = sm9.private_key_extract ('sign', master_public, master_secret, idA)
message = 'abc'
signature = sm9.sign (master_public, Da, message)
assert (sm9.verify (master_public, idA, message, signature))

2. key agreement

idA = 'A'
idB = 'B'
master_public, master_secret = sm9.setup ('keyagreement')
Da = sm9.private_key_extract ('keyagreement', master_public, master_secret, idA)
Db = sm9.private_key_extract ('keyagreement', master_public, master_secret, idB)
xa, Ra = sm9.generate_ephemeral (master_public, idB)
xb, Rb = sm9.generate_ephemeral (master_public, idA)
ska = sm9.generate_session_key (idA, idB, Ra, Rb, Da, xa, master_public, 'A', 128)
skb = sm9.generate_session_key (idA, idB, Ra, Rb, Db, xb, master_public, 'B', 128)
assert (ska == skb)

3. encrypt和decrypt

idA = 'A'
master_public, master_secret = sm9.setup ('encrypt')
Da = sm9.private_key_extract ('encrypt', master_public, master_secret, idA)
message = 'abc'
ct = sm9.kem_dem_enc (master_public, idA, message, 32)
pt = sm9.kem_dem_dec (master_public, idA, Da, ct, 32)
assert (message == pt)