gpg-lacre/lacre/keycache.py

81 lines
2.6 KiB
Python

"""A cache of OpenPGP keys known to Lacre."""
import lacre.text as text
import logging
import GnuPG
LOG = logging.getLogger(__name__)
class KeyCacheMisconfiguration(Exception):
"""Exception used to signal that KeyCache is misconfigured."""
class KeyCache:
"""A store for OpenPGP keys.
Key case is sanitised while loading from GnuPG if so
configured. See mail_case_insensitive parameter in section
[default].
"""
def __init__(self, keyring_dir: str = None):
"""Initialise an empty cache.
With keyring_dir given, set location of the directory from which keys should be loaded.
"""
self._keys = dict()
self._keyring_dir = keyring_dir
def __getitem__(self, fingerpring):
"""Look up email assigned to the given fingerprint."""
return self._keys[fingerpring]
def __setitem__(self, fingerprint, email):
"""Assign an email to a fingerpring, overwriting it if it was already present."""
self._keys[fingerprint] = email
def __contains__(self, fingerprint):
"""Check if the given fingerprint is assigned to an email."""
# This method has to be present for KeyCache to be a dict substitute.
# See mailgate, function _identify_gpg_recipients.
return fingerprint in self._keys
def has_email(self, email):
"""Check if cache contains a key assigned to the given email."""
return email in self._keys.values()
def load(self):
"""Load keyring, replacing any previous contents of the cache."""
LOG.debug('Reloading keys...')
if self._keyring_dir is None:
LOG.error('Keyringn directory not set!')
raise KeyCacheMisconfiguration("Keyring directory not configured")
self.replace_keyring(self._load_keyring_from(self._keyring_dir))
reload = load
def load_keyring_from(self, keyhome: str):
"""Add all identities from keyring stored in KEYHOME."""
self.extend_keyring(self._load_keyring_from(keyhome))
def _load_keyring_from(self, keyring_dir):
return GnuPG.public_keys(keyring_dir)
def replace_keyring(self, keys: dict):
"""Overwrite previously stored key cache with KEYS."""
for fingerprint in keys:
keys[fingerprint] = text.sanitize_case_sense(keys[fingerprint])
LOG.info(f'Storing {len(keys)} keys')
self._keys = keys
def extend_keyring(self, keys: dict):
"""Add all keys from KEYS."""
for fingerprint in keys:
keys[fingerprint] = text.sanitize_case_sense(keys[fingerprint])
LOG.info(f'Adding {len(keys)} keys')
self._keys.update(keys)