Move KeyManager submodule from leap.common to here.

1 files changed, 285 insertions, 0 deletions

diff --git a/src/leap/keymanager/keys.py b/src/leap/keymanager/keys.py
new file mode 100644
index 00000000..44bd587b
--- /dev/null
+++ b/src/leap/keymanager/keys.py
@@ -0,0 +1,285 @@
+# -*- coding: utf-8 -*-
+# keys.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/>.
+
+
+"""
+Abstact key type and encryption scheme representations.
+"""
+
+
+try:
+    import simplejson as json
+except ImportError:
+    import json  # noqa
+import re
+
+
+from abc import ABCMeta, abstractmethod
+from leap.common.check import leap_assert
+
+
+#
+# Dictionary keys used for storing cryptographic keys.
+#
+
+KEY_ADDRESS_KEY = 'address'
+KEY_TYPE_KEY = 'type'
+KEY_ID_KEY = 'key_id'
+KEY_FINGERPRINT_KEY = 'fingerprint'
+KEY_DATA_KEY = 'key_data'
+KEY_PRIVATE_KEY = 'private'
+KEY_LENGTH_KEY = 'length'
+KEY_EXPIRY_DATE_KEY = 'expiry_date'
+KEY_FIRST_SEEN_AT_KEY = 'first_seen_at'
+KEY_LAST_AUDITED_AT_KEY = 'last_audited_at'
+KEY_VALIDATION_KEY = 'validation'
+KEY_TAGS_KEY = 'tags'
+
+
+#
+# Key storage constants
+#
+
+KEYMANAGER_KEY_TAG = 'keymanager-key'
+
+
+#
+# key indexing constants.
+#
+
+TAGS_PRIVATE_INDEX = 'by-tags-private'
+TAGS_ADDRESS_PRIVATE_INDEX = 'by-tags-address-private'
+INDEXES = {
+    TAGS_PRIVATE_INDEX: [
+        KEY_TAGS_KEY,
+        'bool(%s)' % KEY_PRIVATE_KEY,
+    ],
+    TAGS_ADDRESS_PRIVATE_INDEX: [
+        KEY_TAGS_KEY,
+        KEY_ADDRESS_KEY,
+        'bool(%s)' % KEY_PRIVATE_KEY,
+    ]
+}
+
+
+#
+# Key handling utilities
+#
+
+def is_address(address):
+    """
+    Return whether the given C{address} is in the form user@provider.
+
+    :param address: The address to be tested.
+    :type address: str
+    :return: Whether C{address} is in the form user@provider.
+    :rtype: bool
+    """
+    return bool(re.match('[\w.-]+@[\w.-]+', address))
+
+
+def build_key_from_dict(kClass, address, kdict):
+    """
+    Build an C{kClass} key bound to C{address} based on info in C{kdict}.
+
+    :param address: The address bound to the key.
+    :type address: str
+    :param kdict: Dictionary with key data.
+    :type kdict: dict
+    :return: An instance of the key.
+    :rtype: C{kClass}
+    """
+    leap_assert(
+        address == kdict[KEY_ADDRESS_KEY],
+        'Wrong address in key data.')
+    return kClass(
+        address,
+        key_id=kdict[KEY_ID_KEY],
+        fingerprint=kdict[KEY_FINGERPRINT_KEY],
+        key_data=kdict[KEY_DATA_KEY],
+        private=kdict[KEY_PRIVATE_KEY],
+        length=kdict[KEY_LENGTH_KEY],
+        expiry_date=kdict[KEY_EXPIRY_DATE_KEY],
+        first_seen_at=kdict[KEY_FIRST_SEEN_AT_KEY],
+        last_audited_at=kdict[KEY_LAST_AUDITED_AT_KEY],
+        validation=kdict[KEY_VALIDATION_KEY],  # TODO: verify for validation.
+    )
+
+
+#
+# Abstraction for encryption keys
+#
+
+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, private=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.private = private
+        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
+
+    def get_json(self):
+        """
+        Return a JSON string describing this key.
+
+        :return: The JSON string describing this key.
+        :rtype: str
+        """
+        return json.dumps({
+            KEY_ADDRESS_KEY: self.address,
+            KEY_TYPE_KEY: str(self.__class__),
+            KEY_ID_KEY: self.key_id,
+            KEY_FINGERPRINT_KEY: self.fingerprint,
+            KEY_DATA_KEY: self.key_data,
+            KEY_PRIVATE_KEY: self.private,
+            KEY_LENGTH_KEY: self.length,
+            KEY_EXPIRY_DATE_KEY: self.expiry_date,
+            KEY_VALIDATION_KEY: self.validation,
+            KEY_FIRST_SEEN_AT_KEY: self.first_seen_at,
+            KEY_LAST_AUDITED_AT_KEY: self.last_audited_at,
+            KEY_TAGS_KEY: [KEYMANAGER_KEY_TAG],
+        })
+
+    def __repr__(self):
+        """
+        Representation of this class
+        """
+        return u"<%s 0x%s (%s - %s)>" % (
+            self.__class__.__name__,
+            self.key_id,
+            self.address,
+            "priv" if self.private else "publ")
+
+
+#
+# Encryption schemes
+#
+
+class EncryptionScheme(object):
+    """
+    Abstract class for Encryption Schemes.
+
+    A wrapper for a certain encryption schemes should know how to get and put
+    keys in local storage using Soledad, how to generate new keys and how to
+    find out about possibly encrypted content.
+    """
+
+    __metaclass__ = ABCMeta
+
+    def __init__(self, soledad):
+        """
+        Initialize this Encryption Scheme.
+
+        :param soledad: A Soledad instance for local storage of keys.
+        :type soledad: leap.soledad.Soledad
+        """
+        self._soledad = soledad
+        self._init_indexes()
+
+    def _init_indexes(self):
+        """
+        Initialize the database indexes.
+        """
+        # Ask the database for currently existing indexes.
+        db_indexes = dict(self._soledad.list_indexes())
+        # Loop through the indexes we expect to find.
+        for name, expression in INDEXES.items():
+            if name not in db_indexes:
+                # The index does not yet exist.
+                self._soledad.create_index(name, *expression)
+                continue
+            if expression == db_indexes[name]:
+                # The index exists and is up to date.
+                continue
+            # The index exists but the definition is not what expected, so we
+            # delete it and add the proper index expression.
+            self._soledad.delete_index(name)
+            self._soledad.create_index(name, *expression)
+
+    @abstractmethod
+    def get_key(self, address, private=False):
+        """
+        Get key from local storage.
+
+        :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
+
+        :return: The key bound to C{address}.
+        :rtype: EncryptionKey
+        @raise KeyNotFound: If the key was not found on local storage.
+        """
+        pass
+
+    @abstractmethod
+    def put_key(self, key):
+        """
+        Put a key in local storage.
+
+        :param key: The key to be stored.
+        :type key: EncryptionKey
+        """
+        pass
+
+    @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
+        """
+        pass
+
+    @abstractmethod
+    def delete_key(self, key):
+        """
+        Remove C{key} from storage.
+
+        :param key: The key to be removed.
+        :type key: EncryptionKey
+        """
+        pass