# @Description:国密算法

from gmssl import sm2, sm3, sm4, func
from pysmx.SM2 import generate_keypair

ENCODING = "utf8"
SM2_LEN = 64


def bytes_to_hex_bytes(content: bytes) -> bytes:
    """将普通字节转换为十六进制再转换为字节"""
    return bytes.fromhex(content.decode(ENCODING))


def sm2_generate_key() -> tuple[str, str]:
    """生成sm2密钥对"""
    public, private = generate_keypair(SM2_LEN)
    return public.hex(), private.hex()


def sm2_encrypt(content: bytes, public_key: str, private_key: str) -> bytes:
    """使用sm2算法加密"""
    # 创建后端传前端SM2对象
    crypt = sm2.CryptSM2(
        public_key=public_key,
        private_key=private_key
    )
    return crypt.encrypt(content)


def sm2_decrypt(content: str, public_key: str, private_key: str) -> bytes:
    """使用sm2算法解密"""
    # 创建后端传前端SM2对象
    crypt = sm2.CryptSM2(
        public_key=public_key,
        private_key=private_key
    )
    return bytes_to_hex_bytes(crypt.decrypt(bytes.fromhex(content)))


def sm3_encrypt(content: bytes) -> str:
    """生成sm3摘要"""
    return sm3.sm3_hash(func.bytes_to_list(content))


def encode_sm4(value: bytes, key: bytes) -> bytes:
    """SM4加密"""
    crypt_sm4 = sm4.CryptSM4()
    crypt_sm4.set_key(key, sm4.SM4_ENCRYPT)
    # 使用crypt_ecb进行加密value
    encrypt_value = crypt_sm4.crypt_ecb(value)
    return encrypt_value


def decode_sm4(value: str, key: bytes) -> bytes:
    """SM4解密"""
    crypt_sm4 = sm4.CryptSM4()
    crypt_sm4.set_key(key, sm4.SM4_DECRYPT)
    # 将加密数据通过SM_KEY进行解密；
    decrypt_value = crypt_sm4.crypt_ecb(bytes.fromhex(value))
    return bytes_to_hex_bytes(decrypt_value)