# -*- coding: utf-8 -*-

import hashlib

from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives.serialization import load_pem_private_key

def sign_file(private_key, input_path):
    # Generate SHA512 signature of a file using EC private key
    print('Signing packages')
    with open(private_key, 'rb') as f:
        priv_key = load_pem_private_key(f.read(), None, default_backend())
    with open(input_path, 'rb') as f:
        data = f.read()
    return priv_key.sign(data, ec.ECDSA(hashes.SHA512()))

def hash_file(file_path):
    # Calculate SHA512 hash of a file
    sha512 = hashlib.sha512()
    with open(file_path, 'rb') as f:
        while True:
            data = f.read(65536)
            if not data:
                break
            sha512.update(data)
    return sha512.hexdigest()