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Diffstat (limited to 'src/leap/keymanager/gpg.py')
| -rw-r--r-- | src/leap/keymanager/gpg.py | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/src/leap/keymanager/gpg.py b/src/leap/keymanager/gpg.py new file mode 100644 index 0000000..15c1d9f --- /dev/null +++ b/src/leap/keymanager/gpg.py @@ -0,0 +1,397 @@ +# -*- coding: utf-8 -*- +# gpgwrapper.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/>. + + +""" +A GPG wrapper used to handle OpenPGP keys. + +This is a temporary class that will be superseded by the a revised version of +python-gnupg. +""" + + +import os +import gnupg +import re +from gnupg import ( + logger, + _is_sequence, + _make_binary_stream, +) + + +class ListPackets(): + """ + Handle status messages for --list-packets. + """ + + def __init__(self, gpg): + """ + Initialize the packet listing handling class. + + :param gpg: GPG object instance. + :type gpg: gnupg.GPG + """ + self.gpg = gpg + self.nodata = None + self.key = None + self.need_passphrase = None + self.need_passphrase_sym = None + self.userid_hint = None + + def handle_status(self, key, value): + """ + Handle one line of the --list-packets status message. + + :param key: The status message key. + :type key: str + :param value: The status message value. + :type value: str + """ + # TODO: write tests for handle_status + if key == 'NODATA': + self.nodata = True + if key == 'ENC_TO': + # This will only capture keys in our keyring. In the future we + # may want to include multiple unknown keys in this list. + self.key, _, _ = value.split() + if key == 'NEED_PASSPHRASE': + self.need_passphrase = True + if key == 'NEED_PASSPHRASE_SYM': + self.need_passphrase_sym = True + if key == 'USERID_HINT': + self.userid_hint = value.strip().split() + + +class GPGWrapper(gnupg.GPG): + """ + This is a temporary class for handling GPG requests, and should be + replaced by a more general class used throughout the project. + """ + + GNUPG_HOME = os.environ['HOME'] + "/.config/leap/gnupg" + GNUPG_BINARY = "/usr/bin/gpg" # this has to be changed based on OS + + def __init__(self, gpgbinary=GNUPG_BINARY, gnupghome=GNUPG_HOME, + verbose=False, use_agent=False, keyring=None, options=None): + """ + Initialize a GnuPG process wrapper. + + :param gpgbinary: Name for GnuPG binary executable. + :type gpgbinary: C{str} + :param gpghome: Full pathname to directory containing the public and + private keyrings. + :type gpghome: C{str} + :param keyring: Name of alternative keyring file to use. If specified, + the default keyring is not used. + :param verbose: Should some verbose info be output? + :type verbose: bool + :param use_agent: Should pass `--use-agent` to GPG binary? + :type use_agent: bool + :param keyring: Path for the keyring to use. + :type keyring: str + @options: A list of additional options to pass to the GPG binary. + :type options: list + + @raise: RuntimeError with explanation message if there is a problem + invoking gpg. + """ + gnupg.GPG.__init__(self, gnupghome=gnupghome, gpgbinary=gpgbinary, + verbose=verbose, use_agent=use_agent, + keyring=keyring, options=options) + self.result_map['list-packets'] = ListPackets + + def find_key_by_email(self, email, secret=False): + """ + Find user's key based on their email. + + :param email: Email address of key being searched for. + :type email: str + :param secret: Should we search for a secret key? + :type secret: bool + + :return: The fingerprint of the found key. + :rtype: str + """ + for key in self.list_keys(secret=secret): + for uid in key['uids']: + if re.search(email, uid): + return key + raise LookupError("GnuPG public key for email %s not found!" % email) + + def find_key_by_subkey(self, subkey, secret=False): + """ + Find user's key based on a subkey fingerprint. + + :param email: Subkey fingerprint of the key being searched for. + :type email: str + :param secret: Should we search for a secret key? + :type secret: bool + + :return: The fingerprint of the found key. + :rtype: str + """ + for key in self.list_keys(secret=secret): + for sub in key['subkeys']: + if sub[0] == subkey: + return key + raise LookupError( + "GnuPG public key for subkey %s not found!" % subkey) + + def find_key_by_keyid(self, keyid, secret=False): + """ + Find user's key based on the key ID. + + :param email: The key ID of the key being searched for. + :type email: str + :param secret: Should we search for a secret key? + :type secret: bool + + :return: The fingerprint of the found key. + :rtype: str + """ + for key in self.list_keys(secret=secret): + if keyid == key['keyid']: + return key + raise LookupError( + "GnuPG public key for keyid %s not found!" % keyid) + + def find_key_by_fingerprint(self, fingerprint, secret=False): + """ + Find user's key based on the key fingerprint. + + :param email: The fingerprint of the key being searched for. + :type email: str + :param secret: Should we search for a secret key? + :type secret: bool + + :return: The fingerprint of the found key. + :rtype: str + """ + for key in self.list_keys(secret=secret): + if fingerprint == key['fingerprint']: + return key + raise LookupError( + "GnuPG public key for fingerprint %s not found!" % fingerprint) + + def encrypt(self, data, recipient, sign=None, always_trust=True, + passphrase=None, symmetric=False): + """ + Encrypt data using GPG. + + :param data: The data to be encrypted. + :type data: str + :param recipient: The address of the public key to be used. + :type recipient: str + :param sign: Should the encrypted content be signed? + :type sign: bool + :param always_trust: Skip key validation and assume that used keys + are always fully trusted? + :type always_trust: bool + :param passphrase: The passphrase to be used if symmetric encryption + is desired. + :type passphrase: str + :param symmetric: Should we encrypt to a password? + :type symmetric: bool + + :return: An object with encrypted result in the `data` field. + :rtype: gnupg.Crypt + """ + # TODO: devise a way so we don't need to "always trust". + return gnupg.GPG.encrypt(self, data, recipient, sign=sign, + always_trust=always_trust, + passphrase=passphrase, + symmetric=symmetric, + cipher_algo='AES256') + + def decrypt(self, data, always_trust=True, passphrase=None): + """ + Decrypt data using GPG. + + :param data: The data to be decrypted. + :type data: str + :param always_trust: Skip key validation and assume that used keys + are always fully trusted? + :type always_trust: bool + :param passphrase: The passphrase to be used if symmetric encryption + is desired. + :type passphrase: str + + :return: An object with decrypted result in the `data` field. + :rtype: gnupg.Crypt + """ + # TODO: devise a way so we don't need to "always trust". + return gnupg.GPG.decrypt(self, data, always_trust=always_trust, + passphrase=passphrase) + + def send_keys(self, keyserver, *keyids): + """ + Send keys to a keyserver + + :param keyserver: The keyserver to send the keys to. + :type keyserver: str + :param keyids: The key ids to send. + :type keyids: list + + :return: A list of keys sent to server. + :rtype: gnupg.ListKeys + """ + # TODO: write tests for this. + # TODO: write a SendKeys class to handle status for this. + result = self.result_map['list'](self) + gnupg.logger.debug('send_keys: %r', keyids) + data = gnupg._make_binary_stream("", self.encoding) + args = ['--keyserver', keyserver, '--send-keys'] + args.extend(keyids) + self._handle_io(args, data, result, binary=True) + gnupg.logger.debug('send_keys result: %r', result.__dict__) + data.close() + return result + + def encrypt_file(self, file, recipients, sign=None, + always_trust=False, passphrase=None, + armor=True, output=None, symmetric=False, + cipher_algo=None): + """ + Encrypt the message read from the file-like object 'file'. + + :param file: The file to be encrypted. + :type data: file + :param recipient: The address of the public key to be used. + :type recipient: str + :param sign: Should the encrypted content be signed? + :type sign: bool + :param always_trust: Skip key validation and assume that used keys + are always fully trusted? + :type always_trust: bool + :param passphrase: The passphrase to be used if symmetric encryption + is desired. + :type passphrase: str + :param armor: Create ASCII armored output? + :type armor: bool + :param output: Path of file to write results in. + :type output: str + :param symmetric: Should we encrypt to a password? + :type symmetric: bool + :param cipher_algo: Algorithm to use. + :type cipher_algo: str + + :return: An object with encrypted result in the `data` field. + :rtype: gnupg.Crypt + """ + args = ['--encrypt'] + if symmetric: + args = ['--symmetric'] + if cipher_algo: + args.append('--cipher-algo %s' % cipher_algo) + else: + args = ['--encrypt'] + if not _is_sequence(recipients): + recipients = (recipients,) + for recipient in recipients: + args.append('--recipient "%s"' % recipient) + if armor: # create ascii-armored output - set to False for binary + args.append('--armor') + if output: # write the output to a file with the specified name + if os.path.exists(output): + os.remove(output) # to avoid overwrite confirmation message + args.append('--output "%s"' % output) + if sign: + args.append('--sign --default-key "%s"' % sign) + if always_trust: + args.append("--always-trust") + result = self.result_map['crypt'](self) + self._handle_io(args, file, result, passphrase=passphrase, binary=True) + logger.debug('encrypt result: %r', result.data) + return result + + def list_packets(self, data): + """ + List the sequence of packets. + + :param data: The data to extract packets from. + :type data: str + + :return: An object with packet info. + :rtype ListPackets + """ + args = ["--list-packets"] + result = self.result_map['list-packets'](self) + self._handle_io( + args, + _make_binary_stream(data, self.encoding), + result, + ) + return result + + def encrypted_to(self, data): + """ + Return the key to which data is encrypted to. + + :param data: The data to be examined. + :type data: str + + :return: The fingerprint of the key to which data is encrypted to. + :rtype: str + """ + # TODO: make this support multiple keys. + result = self.list_packets(data) + if not result.key: + raise LookupError( + "Content is not encrypted to a GnuPG key!") + try: + return self.find_key_by_keyid(result.key) + except: + return self.find_key_by_subkey(result.key) + + def is_encrypted_sym(self, data): + """ + Say whether some chunk of data is encrypted to a symmetric key. + + :param data: The data to be examined. + :type data: str + + :return: Whether data is encrypted to a symmetric key. + :rtype: bool + """ + result = self.list_packets(data) + return bool(result.need_passphrase_sym) + + def is_encrypted_asym(self, data): + """ + Say whether some chunk of data is encrypted to a private key. + + :param data: The data to be examined. + :type data: str + + :return: Whether data is encrypted to a private key. + :rtype: bool + """ + result = self.list_packets(data) + return bool(result.key) + + def is_encrypted(self, data): + """ + Say whether some chunk of data is encrypted to a key. + + :param data: The data to be examined. + :type data: str + + :return: Whether data is encrypted to a key. + :rtype: bool + """ + return self.is_encrypted_asym(data) or self.is_encrypted_sym(data) |