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| 1 | +#!/usr/bin/env python |
| 2 | + |
| 3 | +# Copyright 2016 Google Inc. All Rights Reserved. |
| 4 | +# |
| 5 | +# Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | +# you may not use this file except in compliance with the License. |
| 7 | +# You may obtain a copy of the License at |
| 8 | +# |
| 9 | +# http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | +# |
| 11 | +# Unless required by applicable law or agreed to in writing, software |
| 12 | +# distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | +# See the License for the specific language governing permissions and |
| 15 | +# limitations under the License. |
| 16 | + |
| 17 | +"""Example of authenticating using access tokens directly on Compute Engine. |
| 18 | +
|
| 19 | +For more information, see the README.md under /compute. |
| 20 | +""" |
| 21 | + |
| 22 | +# [START all] |
| 23 | + |
| 24 | +import argparse |
| 25 | +import base64 |
| 26 | +import os |
| 27 | + |
| 28 | +from cryptography import x509 |
| 29 | +from cryptography.hazmat.backends import default_backend |
| 30 | +from cryptography.hazmat.primitives import hashes |
| 31 | +from cryptography.hazmat.primitives.asymmetric import padding |
| 32 | +import requests |
| 33 | + |
| 34 | + |
| 35 | +GOOGLE_PUBLIC_CERT_URL = ( |
| 36 | + 'https://cloud-certs.storage.googleapis.com/google-cloud-csek-ingress.pem') |
| 37 | + |
| 38 | + |
| 39 | +def get_google_public_cert_key(): |
| 40 | + r = requests.get(GOOGLE_PUBLIC_CERT_URL) |
| 41 | + r.raise_for_status() |
| 42 | + |
| 43 | + # Load the certificate. |
| 44 | + certificate = x509.load_pem_x509_certificate( |
| 45 | + r.text.encode('utf-8'), default_backend()) |
| 46 | + |
| 47 | + # Get the certicate's public key. |
| 48 | + public_key = certificate.public_key() |
| 49 | + |
| 50 | + return public_key |
| 51 | + |
| 52 | + |
| 53 | +def wrap_rsa_key(public_key, private_key_bytes): |
| 54 | + # Use the Google public key to encrypt the customer private key. |
| 55 | + # This means that only the Google private key is capable of decrypting |
| 56 | + # the customer private key. |
| 57 | + wrapped_key = public_key.encrypt( |
| 58 | + private_key_bytes, |
| 59 | + padding.OAEP( |
| 60 | + mgf=padding.MGF1(algorithm=hashes.SHA1()), |
| 61 | + algorithm=hashes.SHA1(), |
| 62 | + label=None)) |
| 63 | + encoded_wrapped_key = base64.b64encode(wrapped_key) |
| 64 | + return encoded_wrapped_key |
| 65 | + |
| 66 | + |
| 67 | +def main(key_file): |
| 68 | + # Generate a new 256-bit private key if no key is specified. |
| 69 | + if not key_file: |
| 70 | + customer_key_bytes = os.urandom(32) |
| 71 | + else: |
| 72 | + with open(key_file, 'rb') as f: |
| 73 | + customer_key_bytes = f.read() |
| 74 | + |
| 75 | + google_public_key = get_google_public_cert_key() |
| 76 | + wrapped_rsa_key = wrap_rsa_key(google_public_key, customer_key_bytes) |
| 77 | + |
| 78 | + print('Base-64 encoded private key: {}'.format( |
| 79 | + base64.b64encode(customer_key_bytes).decode('utf-8'))) |
| 80 | + print('Wrapped RSA key: {}'.format(wrapped_rsa_key.decode('utf-8'))) |
| 81 | + |
| 82 | + |
| 83 | +if __name__ == '__main__': |
| 84 | + parser = argparse.ArgumentParser( |
| 85 | + description=__doc__, |
| 86 | + formatter_class=argparse.RawDescriptionHelpFormatter) |
| 87 | + parser.add_argument( |
| 88 | + '--key_file', help='File containing your binary private key.') |
| 89 | + |
| 90 | + args = parser.parse_args() |
| 91 | + |
| 92 | + main(args.key_file) |
| 93 | +# [END all] |
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