# -*- 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 . """ Key Manager is a Nicknym agent for LEAP client. """ # let's do a little sanity check to see if we're using the wrong gnupg import fileinput import os import sys import tempfile from leap.common import ca_bundle from leap.keymanager.refresher import RandomRefreshPublicKey from ._version import get_versions try: from gnupg.gnupg import GPGUtilities assert(GPGUtilities) # pyflakes happy from gnupg import __version__ as _gnupg_version if '-' in _gnupg_version: # avoid Parsing it as LegacyVersion, get just # the release numbers: _gnupg_version = _gnupg_version.split('-')[0] from pkg_resources import parse_version # We need to make sure that we're not colliding with the infamous # python-gnupg assert(parse_version(_gnupg_version) >= parse_version('1.4.0')) except (ImportError, AssertionError): print "*******" print "Ooops! It looks like there is a conflict in the installed version " print "of gnupg." print "GNUPG_VERSION:", _gnupg_version print print "Disclaimer: Ideally, we would need to work a patch and propose the " print "merge to upstream. But until then do: " print print "% pip uninstall python-gnupg" print "% pip install gnupg" print "*******" sys.exit(1) import logging from twisted.internet import defer from urlparse import urlparse from leap.common.http import HTTPClient from leap.common.events import emit_async, catalog from leap.keymanager.nicknym import Nicknym from leap.keymanager.errors import ( KeyNotFound, KeyNotValidUpgrade, InvalidSignature ) from leap.keymanager.validation import ValidationLevels, can_upgrade from leap.keymanager.openpgp import OpenPGPScheme __version__ = get_versions()['version'] del get_versions logger = logging.getLogger(__name__) # # The Key Manager # class KeyManager(object): # # server's key storage constants # OPENPGP_KEY = 'openpgp' PUBKEY_KEY = "user[public_key]" def __init__(self, address, nickserver_uri, soledad, token=None, ca_cert_path=None, api_uri=None, api_version=None, uid=None, gpgbinary=None, combined_ca_bundle=None): """ Initialize a Key Manager for user's C{address} with provider's nickserver reachable in C{nickserver_uri}. :param address: The email address of the user of this Key Manager. :type address: str :param nickserver_uri: The URI of the nickserver. :type nickserver_uri: str :param soledad: A Soledad instance for local storage of keys. :type soledad: leap.soledad.Soledad :param token: The token for interacting with the webapp API. :type token: str :param ca_cert_path: The path to the CA certificate. :type ca_cert_path: str :param api_uri: The URI of the webapp API. :type api_uri: str :param api_version: The version of the webapp API. :type api_version: str :param uid: The user's UID. :type uid: str :param gpgbinary: Name for GnuPG binary executable. :type gpgbinary: C{str} """ self._address = address self._nickserver_uri = nickserver_uri self._soledad = soledad self._token = token self.ca_cert_path = ca_cert_path self.api_uri = api_uri self.api_version = api_version self.uid = uid self._openpgp = OpenPGPScheme(soledad, gpgbinary=gpgbinary) self._combined_ca_bundle = combined_ca_bundle or self._create_combined_bundle_file() self._async_client = HTTPClient(self._combined_ca_bundle) self._nicknym = Nicknym(self._nickserver_uri, self._ca_cert_path, self._token) self.refresher = None # # destructor # def __del__(self): try: created_tmp_combined_ca_bundle = self._combined_ca_bundle not in \ [ca_bundle.where(), self._ca_cert_path] if created_tmp_combined_ca_bundle: os.remove(self._combined_ca_bundle) except OSError: pass # # utilities # def start_refresher(self): self.refresher = RandomRefreshPublicKey(self._openpgp, self) self.refresher.start() def stop_refresher(self): self.refresher.stop() def _create_combined_bundle_file(self): leap_ca_bundle = ca_bundle.where() if self._ca_cert_path == leap_ca_bundle: return self._ca_cert_path # don't merge file with itself elif not self._ca_cert_path: return leap_ca_bundle tmp_file = tempfile.NamedTemporaryFile(delete=False) with open(tmp_file.name, 'w') as fout: fin = fileinput.input(files=(leap_ca_bundle, self._ca_cert_path)) for line in fin: fout.write(line) fin.close() return tmp_file.name @defer.inlineCallbacks def _get_with_combined_ca_bundle(self, uri, data=None): """ Send a GET request to C{uri} containing C{data}. Instead of using the ca_cert provided on construction time, this version also uses the default certificates shipped with leap.common :param uri: The URI of the request. :type uri: str :param data: The body of the request. :type data: dict, str or file :return: A deferred that will be fired with the GET response :rtype: Deferred """ try: content = yield self._async_client.request(str(uri), 'GET') except Exception as e: logger.warning("There was a problem fetching key: %s" % (e,)) raise KeyNotFound(uri) if not content: raise KeyNotFound(uri) defer.returnValue(content) # # key management # def send_key(self): """ Send user's key 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. :return: A Deferred which fires when the key is sent, or which fails with KeyNotFound if the key was not found in local database. :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ def send(pubkey): d = self._nicknym.put_key(self.uid, pubkey.key_data, self._api_uri, self._api_version) d.addCallback(lambda _: emit_async(catalog.KEYMANAGER_DONE_UPLOADING_KEYS, self._address)) return d d = self.get_key( self._address, private=False, fetch_remote=False) d.addCallback(send) return d @defer.inlineCallbacks def _fetch_keys_from_server_and_store_local(self, address): """ Fetch keys from nickserver and insert them in locale database. :param address: The address bound to the keys. :type address: str :return: A Deferred which fires when the key is in the storage, or which fails with KeyNotFound if the key was not found on nickserver. :rtype: Deferred """ server_keys = yield self._nicknym.fetch_key_with_address(address) # insert keys in local database if self.OPENPGP_KEY in server_keys: # nicknym server is authoritative for its own domain, # for other domains the key might come from key servers. validation_level = ValidationLevels.Weak_Chain _, domain = _split_email(address) if (domain == _get_domain(self._nickserver_uri)): validation_level = ValidationLevels.Provider_Trust yield self.put_raw_key( server_keys['openpgp'], address=address, validation=validation_level) def get_key(self, address, private=False, fetch_remote=True): """ Return a key bound to 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 private: Look for a private key instead of a public one? :type private: bool :param fetch_remote: If key not found in local storage try to fetch from nickserver :type fetch_remote: bool :return: A Deferred which fires with an EncryptionKey bound to address, or which fails with KeyNotFound if no key was found neither locally or in keyserver or fail with KeyVersionError if the key has a format not supported by this version of KeyManager :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ logger.debug("getting key for %s" % (address,)) emit_async(catalog.KEYMANAGER_LOOKING_FOR_KEY, address) def key_found(key): emit_async(catalog.KEYMANAGER_KEY_FOUND, address) return key def key_not_found(failure): if not failure.check(KeyNotFound): return failure emit_async(catalog.KEYMANAGER_KEY_NOT_FOUND, address) # we will only try to fetch a key from nickserver if fetch_remote # is True and the key is not private. if fetch_remote is False or private is True: return failure emit_async(catalog.KEYMANAGER_LOOKING_FOR_KEY, address) d = self._fetch_keys_from_server_and_store_local(address) d.addCallback( lambda _: self._openpgp.get_key(address, private=False)) d.addCallback(key_found) return d # return key if it exists in local database d = self._openpgp.get_key(address, private=private) d.addCallbacks(key_found, key_not_found) return d def get_all_keys(self, private=False): """ Return all keys stored in local database. :param private: Include private keys :type private: bool :return: A Deferred which fires with a list of all keys in local db. :rtype: Deferred """ return self._openpgp.get_all_keys(private) def gen_key(self): """ Generate a key bound to the user's address. :return: A Deferred which fires with the generated EncryptionKey. :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ def signal_finished(key): emit_async( catalog.KEYMANAGER_FINISHED_KEY_GENERATION, self._address) return key emit_async(catalog.KEYMANAGER_STARTED_KEY_GENERATION, self._address) d = self._openpgp.gen_key(self._address) d.addCallback(signal_finished) return d # # Setters/getters # def _get_token(self): return self._token def _set_token(self, token): self._token = token token = property( _get_token, _set_token, doc='The session token.') def _get_ca_cert_path(self): return self._ca_cert_path def _set_ca_cert_path(self, ca_cert_path): self._ca_cert_path = ca_cert_path ca_cert_path = property( _get_ca_cert_path, _set_ca_cert_path, doc='The path to the CA certificate.') def _get_api_uri(self): return self._api_uri def _set_api_uri(self, api_uri): self._api_uri = api_uri api_uri = property( _get_api_uri, _set_api_uri, doc='The webapp API URI.') def _get_api_version(self): return self._api_version def _set_api_version(self, api_version): self._api_version = api_version api_version = property( _get_api_version, _set_api_version, doc='The webapp API version.') def _get_uid(self): return self._uid def _set_uid(self, uid): self._uid = uid uid = property( _get_uid, _set_uid, doc='The uid of the user.') # # encrypt/decrypt and sign/verify API # def encrypt(self, data, address, passphrase=None, sign=None, cipher_algo='AES256', fetch_remote=True): """ Encrypt data with the public key bound to address and sign with with the private key bound to sign address. :param data: The data to be encrypted. :type data: str :param address: The address to encrypt it for. :type address: str :param passphrase: The passphrase for the secret key used for the signature. :type passphrase: str :param sign: The address to be used for signature. :type sign: str :param cipher_algo: The cipher algorithm to use. :type cipher_algo: str :param fetch_remote: If key is not found in local storage try to fetch from nickserver :type fetch_remote: bool :return: A Deferred which fires with the encrypted data as str, or which fails with KeyNotFound if no keys were found neither locally or in keyserver or fails with KeyVersionError if the key format is not supported or fails with EncryptError if failed encrypting for some reason. :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ @defer.inlineCallbacks def encrypt(keys): pubkey, signkey = keys encrypted = yield self._openpgp.encrypt( data, pubkey, passphrase, sign=signkey, cipher_algo=cipher_algo) if not pubkey.encr_used: pubkey.encr_used = True yield self._openpgp.put_key(pubkey) defer.returnValue(encrypted) dpub = self.get_key(address, private=False, fetch_remote=fetch_remote) dpriv = defer.succeed(None) if sign is not None: dpriv = self.get_key(sign, private=True) d = defer.gatherResults([dpub, dpriv], consumeErrors=True) d.addCallbacks(encrypt, self._extract_first_error) return d def decrypt(self, data, address, passphrase=None, verify=None, fetch_remote=True): """ Decrypt data using private key from address and verify with public key bound to verify address. :param data: The data to be decrypted. :type data: str :param address: The address to whom data was encrypted. :type address: str :param passphrase: The passphrase for the secret key used for decryption. :type passphrase: str :param verify: The address to be used for signature. :type verify: str :param fetch_remote: If key for verify not found in local storage try to fetch from nickserver :type fetch_remote: bool :return: A Deferred which fires with: * (decripted str, signing key) if validation works * (decripted str, KeyNotFound) if signing key not found * (decripted str, InvalidSignature) if signature is invalid * KeyNotFound failure if private key not found * DecryptError failure if decription failed :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ @defer.inlineCallbacks def decrypt(keys): pubkey, privkey = keys decrypted, signed = yield self._openpgp.decrypt( data, privkey, passphrase=passphrase, verify=pubkey) if pubkey is None: signature = KeyNotFound(verify) elif signed: signature = pubkey if not pubkey.sign_used: pubkey.sign_used = True yield self._openpgp.put_key(pubkey) defer.returnValue((decrypted, signature)) else: signature = InvalidSignature( 'Failed to verify signature with key %s' % (pubkey.fingerprint,)) defer.returnValue((decrypted, signature)) dpriv = self.get_key(address, private=True) dpub = defer.succeed(None) if verify is not None: dpub = self.get_key(verify, private=False, fetch_remote=fetch_remote) dpub.addErrback(lambda f: None if f.check(KeyNotFound) else f) d = defer.gatherResults([dpub, dpriv], consumeErrors=True) d.addCallbacks(decrypt, self._extract_first_error) return d def _extract_first_error(self, failure): return failure.value.subFailure def sign(self, data, address, digest_algo='SHA512', clearsign=False, detach=True, binary=False): """ Sign data with private key bound to address. :param data: The data to be signed. :type data: str :param address: The address to be used to sign. :type address: EncryptionKey :param digest_algo: The hash digest to use. :type digest_algo: str :param clearsign: If True, create a cleartext signature. :type clearsign: bool :param detach: If True, create a detached signature. :type detach: bool :param binary: If True, do not ascii armour the output. :type binary: bool :return: A Deferred which fires with the signed data as str or fails with KeyNotFound if no key was found neither locally or in keyserver or fails with SignFailed if there was any error signing. :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ def sign(privkey): return self._openpgp.sign( data, privkey, digest_algo=digest_algo, clearsign=clearsign, detach=detach, binary=binary) d = self.get_key(address, private=True) d.addCallback(sign) return d def verify(self, data, address, detached_sig=None, fetch_remote=True): """ Verify signed data with private key bound to address, eventually using detached_sig. :param data: The data to be verified. :type data: str :param address: The address to be used to verify. :type address: EncryptionKey :param detached_sig: A detached signature. If given, C{data} is verified using this detached signature. :type detached_sig: str :param fetch_remote: If key for verify not found in local storage try to fetch from nickserver :type fetch_remote: bool :return: A Deferred which fires with the signing EncryptionKey if signature verifies, or which fails with InvalidSignature if signature don't verifies or fails with KeyNotFound if no key was found neither locally or in keyserver. :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ def verify(pubkey): signed = self._openpgp.verify( data, pubkey, detached_sig=detached_sig) if signed: if not pubkey.sign_used: pubkey.sign_used = True d = self._openpgp.put_key(pubkey) d.addCallback(lambda _: pubkey) return d return pubkey else: raise InvalidSignature( 'Failed to verify signature with key %s' % (pubkey.fingerprint,)) d = self.get_key(address, private=False, fetch_remote=fetch_remote) d.addCallback(verify) return d def delete_key(self, key): """ Remove key from storage. :param key: The key to be removed. :type key: EncryptionKey :return: A Deferred which fires when the key is deleted, or which fails KeyNotFound if the key was not found on local storage. :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ return self._openpgp.delete_key(key) def put_key(self, key): """ Put key bound to address in local storage. :param key: The key to be stored :type key: EncryptionKey :return: A Deferred which fires when the key is in the storage, or which fails with KeyNotValidUpdate if a key with the same uid exists and the new one is not a valid update for it. :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ def old_key_not_found(failure): if failure.check(KeyNotFound): return None else: return failure def check_upgrade(old_key): if key.private or can_upgrade(key, old_key): return self._openpgp.put_key(key) else: raise KeyNotValidUpgrade( "Key %s can not be upgraded by new key %s" % (old_key.fingerprint, key.fingerprint)) d = self._openpgp.get_key(key.address, private=key.private) d.addErrback(old_key_not_found) d.addCallback(check_upgrade) return d def put_raw_key(self, key, address, validation=ValidationLevels.Weak_Chain): """ Put raw key bound to address in local storage. :param key: The ascii key to be stored :type key: str :param address: address for which this key will be active :type address: str :param validation: validation level for this key (default: 'Weak_Chain') :type validation: ValidationLevels :return: A Deferred which fires when the key is in the storage, or which fails with KeyAddressMismatch if address doesn't match any uid on the key or fails with KeyNotFound if no OpenPGP material was found in key or fails with KeyNotValidUpdate if a key with the same uid exists and the new one is not a valid update for it. :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ pubkey, privkey = self._openpgp.parse_key(key, address) if pubkey is None: return defer.fail(KeyNotFound(key)) pubkey.validation = validation d = self.put_key(pubkey) if privkey is not None: d.addCallback(lambda _: self.put_key(privkey)) return d @defer.inlineCallbacks def fetch_key(self, address, uri, validation=ValidationLevels.Weak_Chain): """ Fetch a public key bound to address from the network and put it in local storage. :param address: The email address of the key. :type address: str :param uri: The URI of the key. :type uri: str :param validation: validation level for this key (default: 'Weak_Chain') :type validation: ValidationLevels :return: A Deferred which fires when the key is in the storage, or which fails with KeyNotFound: if not valid key on uri or fails with KeyAddressMismatch if address doesn't match any uid on the key or fails with KeyNotValidUpdate if a key with the same uid exists and the new one is not a valid update for it. :rtype: Deferred :raise UnsupportedKeyTypeError: if invalid key type """ logger.info("Fetch key for %s from %s" % (address, uri)) key_content = yield self._get_with_combined_ca_bundle(uri) pubkey, _ = self._openpgp.parse_key(key_content, address) if pubkey is None: raise KeyNotFound(uri) pubkey.validation = validation yield self.put_key(pubkey) def _split_email(address): """ Split username and domain from an email address :param address: an email address :type address: str :return: username and domain from the email address :rtype: (str, str) """ if address.count("@") != 1: return None return address.split("@") def _get_domain(url): """ Get the domain from an url :param url: an url :type url: str :return: the domain part of the url :rtype: str """ return urlparse(url).hostname