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Diffstat (limited to 'src')
| -rw-r--r-- | src/leap/common/keymanager/__init__.py | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/src/leap/common/keymanager/__init__.py b/src/leap/common/keymanager/__init__.py new file mode 100644 index 0000000..71aaddd --- /dev/null +++ b/src/leap/common/keymanager/__init__.py @@ -0,0 +1,232 @@ +# -*- coding: utf-8 -*- +# __init__.py +# Copyright (C) 2013 LEAP +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + + +""" +Key Manager is a Nicknym agent for LEAP client. +""" + + +try: + import simplejson as json +except ImportError: + import json # noqa + + +from abc import ABCMeta, abstractmethod +from u1db.errors import HTTPError + + +# +# Key types +# + +class EncryptionKey(object): + """ + Abstract class for encryption keys. + + A key is "validated" if the nicknym agent has bound the user address to a + public key. Nicknym supports three different levels of key validation: + + * Level 3 - path trusted: A path of cryptographic signatures can be traced + from a trusted key to the key under evaluation. By default, only the + provider key from the user's provider is a "trusted key". + * level 2 - provider signed: The key has been signed by a provider key for + the same domain, but the provider key is not validated using a trust + path (i.e. it is only registered) + * level 1 - registered: The key has been encountered and saved, it has no + signatures (that are meaningful to the nicknym agent). + """ + + __metaclass__ = ABCMeta + + def __init__(self, address, key_id=None, fingerprint=None, + key_data=None, length=None, expiry_date=None, + validation=None, first_seen_at=None, + last_audited_at=None): + self.address = address + self.key_id = key_id + self.fingerprint = fingerprint + self.key_data = key_data + self.length = length + self.expiry_date = expiry_date + self.validation = validation + self.first_seen_at = first_seen_at + self.last_audited_at = last_audited_at + + @abstractmethod + def get_json(self): + """ + Return a JSON string describing this key. + + @return: The JSON string describing this key. + @rtype: str + """ + + +# +# Key wrappers +# + +class KeyTypeWrapper(object): + """ + Abstract class for Key Type Wrappers. + + A wrapper for a certain key type should know how to get and put keys in + local storage using Soledad and also how to generate new keys. + """ + + __metaclass__ = ABCMeta + + @abstractmethod + def get_key(self, address): + """ + Get key from local storage. + + @param address: The address bound to the key. + @type address: str + + @return: The key bound to C{address}. + @rtype: EncryptionKey + @raise KeyNotFound: If the key was not found on local storage. + """ + + @abstractmethod + def put_key(self, key): + """ + Put a key in local storage. + + @param key: The key to be stored. + @type key: EncryptionKey + """ + + @abstractmethod + def gen_key(self, address): + """ + Generate a new key. + + @param address: The address bound to the key. + @type address: str + @return: The key bound to C{address}. + @rtype: EncryptionKey + """ + + +# +# Key manager +# + + +class KeyNotFound(Exception): + """ + Raised when key was no found on keyserver. + """ + + +class KeyManager(object): + + def __init__(self, address, url): + """ + Initialize a Key Manager for user's C{address} with provider's + nickserver reachable in C{url}. + + @param address: The address of the user of this Key Manager. + @type address: str + @param url: The URL of the key manager. + @type url: str + """ + self.address = address + self.url = url + + def send_key(self, ktype, send_private=False, password=None): + """ + Send user's key of type C{ktype} to provider. + + Public key bound to user's is sent to provider, which will sign it and + replace any prior keys for the same address in its database. + + If C{send_private} is True, then the private key is encrypted with + C{password} and sent to server in the same request, together with a + hash string of user's address and password. The encrypted private key + will be saved in the server in a way it is publicly retrievable + through the hash string. + + @param address: The address bound to the key. + @type address: str + @param ktype: The type of the key. + @type ktype: KeyType + + @raise httplib.HTTPException: + """ + + def get_key(self, address, ktype): + """ + Return a key of type C{ktype} bound to C{address}. + + First, search for the key in local storage. If it is not available, + then try to fetch from nickserver. + + @param address: The address bound to the key. + @type address: str + @param ktype: The type of the key. + @type ktype: KeyType + + @return: A key of type C{ktype} bound to C{address}. + @rtype: EncryptionKey + @raise KeyNotFound: If the key was not found both locally and in + keyserver. + """ + try: + return wrapper_map[ktype].get_key(address) + except KeyNotFound: + key = filter(lambda k: isinstance(k, ktype), + self._fetch_keys(address)) + if key is None + raise KeyNotFound() + wrapper_map[ktype].put_key(key) + return key + + + def _fetch_keys(self, address): + """ + Fetch keys bound to C{address} from nickserver. + + @param address: The address bound to the keys. + @type address: str + + @return: A list of keys bound to C{address}. + @rtype: list of EncryptionKey + @raise KeyNotFound: If the key was not found on nickserver. + @raise httplib.HTTPException: + """ + + def refresh_keys(self): + """ + Update the user's db of validated keys to see if there are changes. + """ + + def gen_key(self, ktype): + """ + Generate a key of type C{ktype} bound to the user's address. + + @param ktype: The type of the key. + @type ktype: KeyType + + @return: The generated key. + @rtype: EncryptionKey + """ + return wrapper_map[ktype].gen_key(self.address) |