import base64

from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization


def get_pkey(key_path, passphrase):
    """Load private key from file."""
    with open(key_path, "rb") as key:
        p_key = serialization.load_pem_private_key(key.read(), password=passphrase.encode(), backend=default_backend())
    return p_key.private_bytes(
        encoding=serialization.Encoding.DER,
        format=serialization.PrivateFormat.PKCS8,
        encryption_algorithm=serialization.NoEncryption(),
    )


def decode_sm_pkey(sm_private_key):
    return base64.b64decode(bytes(sm_private_key, encoding="utf-8"))