client.create_key(_get_vault_url(), key_name, 'RSA')
print('Created key vault key: ' + key_name)
# create a random AES key to wrap
to_wrap = os.urandom(16)
print('\noriginal value:')
print(to_wrap)
# wrap the key
wrapped = client.wrap_key(vault_base_url=_get_vault_url(),
key_name=key_name,
key_version='',
algorithm='RSA-OAEP',
value=to_wrap)
print('\nwrap_key result:')
print(wrapped.result)
unwrapped = client.unwrap_key(vault_base_url=_get_vault_url(),
key_name=key_name,
key_version='',
algorithm='RSA-OAEP',
value=wrapped.result)
# delete the key
client.delete_key(_get_vault_url(), key_name)
print('\nunwrap result:')
print(unwrapped.result)
class AESKeyWrapper:
""" Wrapper for key wrapping functions.
Key is wrapped localy with public key retrieved from Azure KeyVault.
Uses Azure KeyVault API to unwrap the key.
"""
def __init__(self, vault, client_id, secret, tenant, key_name,
key_version):
"""
Wrapper constructor.
:param str vault: Azure KeyVault url.
:param str client_id: Azure Client Id.
:param str secret: Azure Client secret.
:param str tenant: Azure tenant id.
:param str key_name: Azure KeyVault key name.
:param str key_version: Azure KeyVault key version.
"""
self._key_name = key_name
self._key_version = key_version
self._vault = vault
self._client_id = client_id
self._secret = secret
self._tenant = tenant
self._credentials = ServicePrincipalCredentials(
client_id=self._client_id,
secret=self._secret,
tenant=self._tenant)
self.kvclient = KeyVaultClient(self._credentials)
def wrap_aes_key_local(self, aes_key, public_key):
"""
Wraps AES key locally.
Uses RSA-OAEP algorithm to wrap provided key.
:param str aes_key: unencrypted AES key.
:param str public_key: public part of RSA key.
:return: String with encrypted AES key.
"""
int_n = self._bytes_to_int(public_key.n)
int_e = self._bytes_to_int(public_key.e)
public_numbers = RSAPublicNumbers(int_e, int_n)
public_key = public_numbers.public_key(default_backend())
wrapped_key = public_key.encrypt(
aes_key,
padding.OAEP(mgf=padding.MGF1(algorithm=hashes.SHA1()),
algorithm=hashes.SHA1(),
label=None))
return wrapped_key
def unwrap_aes_key(self, wrapped_key):
"""
Unwraps AES key with Azure KeyVault.
Uses RSA-OAEP algorithm to unwrap provided key.
:param str wrapped_key: encrypted AES key.
:return: String with unencrypted AES key.
"""
return self.kvclient.unwrap_key(self._vault, self._key_name,
self._key_version, 'RSA-OAEP',
wrapped_key).result
def get_public_key(self):
""" Retrieve public key from Azure KeyVault.
:return: JsonWebKey with public RSA key.
"""
key_bundle = self.kvclient.get_key(self._vault, self._key_name,
self._key_version)
return key_bundle.key
def _bytes_to_int(self, bytes):
""" Helper function to convert bytes array to int. """
result = 0
for b in bytes:
result = result * 256 + ord(b)
return result
