python 私钥加密后再进行sha256加密

pri_file = 'client_private.pem'
if os.path.exists(pri_file):
    pass
else:
    random_gen = Random.new().read
    # 生成秘钥对实例对象：1024是秘钥的长度
    rsa = RSA.generate(4096, random_gen)
    # Client的秘钥对的生成
    private_pem = rsa.exportKey()
    with open(pri_file, "wb") as f:
        f.write(private_pem)

def encrypt(plaintext):
    """
    client 私进行加密
    """
    # 加载私钥
    rsa_key = RSA.import_key(open(pri_file).read())
    # 加密
    cipher_rsa = Cipher_PKC.new(rsa_key)
    en_data = cipher_rsa.encrypt(plaintext.encode("utf-8"))  # 加密
    data_sha256 = hashlib.sha256(en_data).hexdigest()
    return data_sha256