CasperSecurity
"""
Core API functions and initialization routines.
"""
import configparser
import os
import sys
import logging
import typing
from . import backend, credentials
from .util import platform_ as platform
from .backends import fail
log = logging.getLogger(__name__)
_keyring_backend = None
def set_keyring(keyring):
"""Set current keyring backend."""
global _keyring_backend
if not isinstance(keyring, backend.KeyringBackend):
raise TypeError("The keyring must be an instance of KeyringBackend")
_keyring_backend = keyring
def get_keyring() -> backend.KeyringBackend:
"""Get current keyring backend."""
if _keyring_backend is None:
init_backend()
return typing.cast(backend.KeyringBackend, _keyring_backend)
def disable():
"""
Configure the null keyring as the default.
"""
root = platform.config_root()
try:
os.makedirs(root)
except OSError:
pass
filename = os.path.join(root, 'keyringrc.cfg')
if os.path.exists(filename):
msg = f"Refusing to overwrite {filename}"
raise RuntimeError(msg)
with open(filename, 'w') as file:
file.write('[backend]\ndefault-keyring=keyring.backends.null.Keyring')
def get_password(service_name: str, username: str) -> typing.Optional[str]:
"""Get password from the specified service."""
return get_keyring().get_password(service_name, username)
def set_password(service_name: str, username: str, password: str) -> None:
"""Set password for the user in the specified service."""
get_keyring().set_password(service_name, username, password)
def delete_password(service_name: str, username: str) -> None:
"""Delete the password for the user in the specified service."""
get_keyring().delete_password(service_name, username)
def get_credential(
service_name: str, username: typing.Optional[str]
) -> typing.Optional[credentials.Credential]:
"""Get a Credential for the specified service."""
return get_keyring().get_credential(service_name, username)
def recommended(backend):
return backend.priority >= 1
def init_backend(limit=None):
"""
Load a detected backend.
"""
set_keyring(_detect_backend(limit))
def _detect_backend(limit=None):
"""
Return a keyring specified in the config file or infer the best available.
Limit, if supplied, should be a callable taking a backend and returning
True if that backend should be included for consideration.
"""
# save the limit for the chainer to honor
backend._limit = limit
return (
load_env()
or load_config()
or max(
# all keyrings passing the limit filter
filter(limit, backend.get_all_keyring()),
default=fail.Keyring(),
key=backend.by_priority,
)
)
def _load_keyring_class(keyring_name):
"""
Load the keyring class indicated by name.
These popular names are tested to ensure their presence.
>>> popular_names = [
... 'keyring.backends.Windows.WinVaultKeyring',
... 'keyring.backends.macOS.Keyring',
... 'keyring.backends.kwallet.DBusKeyring',
... 'keyring.backends.SecretService.Keyring',
... ]
>>> list(map(_load_keyring_class, popular_names))
[...]
"""
module_name, sep, class_name = keyring_name.rpartition('.')
__import__(module_name)
module = sys.modules[module_name]
return getattr(module, class_name)
def load_keyring(keyring_name):
"""
Load the specified keyring by name (a fully-qualified name to the
keyring, such as 'keyring.backends.file.PlaintextKeyring')
"""
class_ = _load_keyring_class(keyring_name)
# invoke the priority to ensure it is viable, or raise a RuntimeError
class_.priority
return class_()
def load_env():
"""Load a keyring configured in the environment variable."""
try:
return load_keyring(os.environ['PYTHON_KEYRING_BACKEND'])
except KeyError:
pass
def load_config():
"""Load a keyring using the config file in the config root."""
filename = 'keyringrc.cfg'
keyring_cfg = os.path.join(platform.config_root(), filename)
if not os.path.exists(keyring_cfg):
return
config = configparser.RawConfigParser()
config.read(keyring_cfg)
_load_keyring_path(config)
# load the keyring class name, and then load this keyring
try:
if config.has_section("backend"):
keyring_name = config.get("backend", "default-keyring").strip()
else:
raise configparser.NoOptionError('backend', 'default-keyring')
except (configparser.NoOptionError, ImportError):
logger = logging.getLogger('keyring')
logger.warning(
"Keyring config file contains incorrect values.\n"
+ "Config file: %s" % keyring_cfg
)
return
return load_keyring(keyring_name)
def _load_keyring_path(config):
"load the keyring-path option (if present)"
try:
path = config.get("backend", "keyring-path").strip()
sys.path.insert(0, path)
except (configparser.NoOptionError, configparser.NoSectionError):
pass