Merge remote-tracking branch 'drebs/feature/key-manager' into develop

1 files changed, 397 insertions, 0 deletions

diff --git a/src/leap/common/keymanager/gpg.py b/src/leap/common/keymanager/gpg.py
new file mode 100644
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+++ b/src/leap/common/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+This is a temporary class that will be superseded by the a revised version of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)