CasperSecurity
# SecretStorage module for Python
# Access passwords using the SecretService DBus API
# Author: Dmitry Shachnev, 2013-2018
# License: 3-clause BSD, see LICENSE file
"""SecretStorage item contains a *secret*, some *attributes* and a
*label* visible to user. Editing all these properties and reading the
secret is possible only when the :doc:`collection <collection>` storing
the item is unlocked. The collection can be unlocked using collection's
:meth:`~secretstorage.collection.Collection.unlock` method."""
from typing import Dict, Optional
from jeepney.io.blocking import DBusConnection
from secretstorage.defines import SS_PREFIX
from secretstorage.dhcrypto import Session
from secretstorage.exceptions import LockedException, PromptDismissedException
from secretstorage.util import DBusAddressWrapper, \
exec_prompt, open_session, format_secret, unlock_objects
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.backends import default_backend
ITEM_IFACE = SS_PREFIX + 'Item'
class Item(object):
"""Represents a secret item."""
def __init__(self, connection: DBusConnection,
item_path: str, session: Optional[Session] = None) -> None:
self.item_path = item_path
self._item = DBusAddressWrapper(item_path, ITEM_IFACE, connection)
self._item.get_property('Label')
self.session = session
self.connection = connection
def __eq__(self, other: "DBusConnection") -> bool:
assert isinstance(other.item_path, str)
return self.item_path == other.item_path
def is_locked(self) -> bool:
"""Returns :const:`True` if item is locked, otherwise
:const:`False`."""
return bool(self._item.get_property('Locked'))
def ensure_not_locked(self) -> None:
"""If collection is locked, raises
:exc:`~secretstorage.exceptions.LockedException`."""
if self.is_locked():
raise LockedException('Item is locked!')
def unlock(self) -> bool:
"""Requests unlocking the item. Usually, this means that the
whole collection containing this item will be unlocked.
Returns a boolean representing whether the prompt has been
dismissed; that means :const:`False` on successful unlocking
and :const:`True` if it has been dismissed.
.. versionadded:: 2.1.2
.. versionchanged:: 3.0
No longer accepts the ``callback`` argument.
"""
return unlock_objects(self.connection, [self.item_path])
def get_attributes(self) -> Dict[str, str]:
"""Returns item attributes (dictionary)."""
attrs = self._item.get_property('Attributes')
return dict(attrs)
def set_attributes(self, attributes: Dict[str, str]) -> None:
"""Sets item attributes to `attributes` (dictionary)."""
self._item.set_property('Attributes', 'a{ss}', attributes)
def get_label(self) -> str:
"""Returns item label (unicode string)."""
label = self._item.get_property('Label')
assert isinstance(label, str)
return label
def set_label(self, label: str) -> None:
"""Sets item label to `label`."""
self.ensure_not_locked()
self._item.set_property('Label', 's', label)
def delete(self) -> None:
"""Deletes the item."""
self.ensure_not_locked()
prompt, = self._item.call('Delete', '')
if prompt != "/":
dismissed, _result = exec_prompt(self.connection, prompt)
if dismissed:
raise PromptDismissedException('Prompt dismissed.')
def get_secret(self) -> bytes:
"""Returns item secret (bytestring)."""
self.ensure_not_locked()
if not self.session:
self.session = open_session(self.connection)
secret, = self._item.call('GetSecret', 'o', self.session.object_path)
if not self.session.encrypted:
return bytes(secret[2])
assert self.session.aes_key is not None
aes = algorithms.AES(self.session.aes_key)
aes_iv = bytes(secret[1])
decryptor = Cipher(aes, modes.CBC(aes_iv), default_backend()).decryptor()
encrypted_secret = secret[2]
padded_secret = decryptor.update(bytes(encrypted_secret)) + decryptor.finalize()
assert isinstance(padded_secret, bytes)
return padded_secret[:-padded_secret[-1]]
def get_secret_content_type(self) -> str:
"""Returns content type of item secret (string)."""
self.ensure_not_locked()
if not self.session:
self.session = open_session(self.connection)
secret, = self._item.call('GetSecret', 'o', self.session.object_path)
return str(secret[3])
def set_secret(self, secret: bytes,
content_type: str = 'text/plain') -> None:
"""Sets item secret to `secret`. If `content_type` is given,
also sets the content type of the secret (``text/plain`` by
default)."""
self.ensure_not_locked()
if not self.session:
self.session = open_session(self.connection)
_secret = format_secret(self.session, secret, content_type)
self._item.call('SetSecret', '(oayays)', _secret)
def get_created(self) -> int:
"""Returns UNIX timestamp (integer) representing the time
when the item was created.
.. versionadded:: 1.1"""
created = self._item.get_property('Created')
assert isinstance(created, int)
return created
def get_modified(self) -> int:
"""Returns UNIX timestamp (integer) representing the time
when the item was last modified."""
modified = self._item.get_property('Modified')
assert isinstance(modified, int)
return modified