Split client and server in two different packages and refactor.

1 files changed, 0 insertions, 544 deletions

diff --git a/src/leap/soledad/backends/leap_backend.py b/src/leap/soledad/backends/leap_backend.py
deleted file mode 100644
index 4d92db37..00000000
--- a/src/leap/soledad/backends/leap_backend.py
+++ /dev/null
@@ -1,544 +0,0 @@
-# -*- coding: utf-8 -*-
-# leap_backend.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 U1DB backend for encrypting data before sending to server and decrypting
-after receiving.
-"""
-
-import simplejson as json
-import hashlib
-import hmac
-import binascii
-
-
-from u1db import Document
-from u1db.remote import utils
-from u1db.errors import BrokenSyncStream
-from u1db.remote.http_target import HTTPSyncTarget
-
-
-from leap.soledad import soledad_assert
-from leap.soledad.crypto import (
-    EncryptionMethods,
-    UnknownEncryptionMethod,
-)
-from leap.soledad.auth import TokenBasedAuth
-
-
-#
-# Exceptions
-#
-
-class DocumentNotEncrypted(Exception):
-    """
-    Raised for failures in document encryption.
-    """
-    pass
-
-
-class UnknownEncryptionScheme(Exception):
-    """
-    Raised when trying to decrypt from unknown encryption schemes.
-    """
-    pass
-
-
-class UnknownMacMethod(Exception):
-    """
-    Raised when trying to authenticate document's content with unknown MAC
-    mehtod.
-    """
-    pass
-
-
-class WrongMac(Exception):
-    """
-    Raised when failing to authenticate document's contents based on MAC.
-    """
-
-
-#
-# Encryption schemes used for encryption.
-#
-
-class EncryptionSchemes(object):
-    """
-    Representation of encryption schemes used to encrypt documents.
-    """
-
-    NONE = 'none'
-    SYMKEY = 'symkey'
-    PUBKEY = 'pubkey'
-
-
-class MacMethods(object):
-    """
-    Representation of MAC methods used to authenticate document's contents.
-    """
-
-    HMAC = 'hmac'
-
-
-#
-# Crypto utilities for a LeapDocument.
-#
-
-ENC_JSON_KEY = '_enc_json'
-ENC_SCHEME_KEY = '_enc_scheme'
-ENC_METHOD_KEY = '_enc_method'
-ENC_IV_KEY = '_enc_iv'
-MAC_KEY = '_mac'
-MAC_METHOD_KEY = '_mac_method'
-
-
-def mac_doc(crypto, doc_id, doc_rev, ciphertext, mac_method):
-    """
-    Calculate a MAC for C{doc} using C{ciphertext}.
-
-    Current MAC method used is HMAC, with the following parameters:
-
-        * key: sha256(storage_secret, doc_id)
-        * msg: doc_id + doc_rev + ciphertext
-        * digestmod: sha256
-
-    @param crypto: A SoledadCryto instance used to perform the encryption.
-    @type crypto: leap.soledad.crypto.SoledadCrypto
-    @param doc_id: The id of the document.
-    @type doc_id: str
-    @param doc_rev: The revision of the document.
-    @type doc_rev: str
-    @param ciphertext: The content of the document.
-    @type ciphertext: str
-    @param mac_method: The MAC method to use.
-    @type mac_method: str
-
-    @return: The calculated MAC.
-    @rtype: str
-    """
-    if mac_method == MacMethods.HMAC:
-        return hmac.new(
-            crypto.doc_mac_key(doc_id),
-            str(doc_id) + str(doc_rev) + ciphertext,
-            hashlib.sha256).digest()
-    # raise if we do not know how to handle this MAC method
-    raise UnknownMacMethod('Unknown MAC method: %s.' % mac_method)
-
-
-def encrypt_doc(crypto, doc):
-    """
-    Encrypt C{doc}'s content.
-
-    Encrypt doc's contents using AES-256 CTR mode and return a valid JSON
-    string representing the following:
-
-        {
-            ENC_JSON_KEY: '<encrypted doc JSON string>',
-            ENC_SCHEME_KEY: 'symkey',
-            ENC_METHOD_KEY: EncryptionMethods.AES_256_CTR,
-            ENC_IV_KEY: '<the initial value used to encrypt>',
-            MAC_KEY: '<mac>'
-            MAC_METHOD_KEY: 'hmac'
-        }
-
-    @param crypto: A SoledadCryto instance used to perform the encryption.
-    @type crypto: leap.soledad.crypto.SoledadCrypto
-    @param doc: The document with contents to be encrypted.
-    @type doc: LeapDocument
-
-    @return: The JSON serialization of the dict representing the encrypted
-        content.
-    @rtype: str
-    """
-    soledad_assert(doc.is_tombstone() is False)
-    # encrypt content using AES-256 CTR mode
-    iv, ciphertext = crypto.encrypt_sym(
-        doc.get_json(),
-        crypto.doc_passphrase(doc.doc_id),
-        method=EncryptionMethods.AES_256_CTR)
-    # Return a representation for the encrypted content. In the following, we
-    # convert binary data to hexadecimal representation so the JSON
-    # serialization does not complain about what it tries to serialize.
-    hex_ciphertext = binascii.b2a_hex(ciphertext)
-    return json.dumps({
-        ENC_JSON_KEY: hex_ciphertext,
-        ENC_SCHEME_KEY: EncryptionSchemes.SYMKEY,
-        ENC_METHOD_KEY: EncryptionMethods.AES_256_CTR,
-        ENC_IV_KEY: iv,
-        MAC_KEY: binascii.b2a_hex(mac_doc(  # store the mac as hex.
-            crypto, doc.doc_id, doc.rev,
-            ciphertext,
-            MacMethods.HMAC)),
-        MAC_METHOD_KEY: MacMethods.HMAC,
-    })
-
-
-def decrypt_doc(crypto, doc):
-    """
-    Decrypt C{doc}'s content.
-
-    Return the JSON string representation of the document's decrypted content.
-
-    The content of the document should have the following structure:
-
-        {
-            ENC_JSON_KEY: '<enc_blob>',
-            ENC_SCHEME_KEY: '<enc_scheme>',
-            ENC_METHOD_KEY: '<enc_method>',
-            ENC_IV_KEY: '<initial value used to encrypt>',  # (optional)
-            MAC_KEY: '<mac>'
-            MAC_METHOD_KEY: 'hmac'
-        }
-
-    C{enc_blob} is the encryption of the JSON serialization of the document's
-    content. For now Soledad just deals with documents whose C{enc_scheme} is
-    EncryptionSchemes.SYMKEY and C{enc_method} is
-    EncryptionMethods.AES_256_CTR.
-
-    @param crypto: A SoledadCryto instance to perform the encryption.
-    @type crypto: leap.soledad.crypto.SoledadCrypto
-    @param doc: The document to be decrypted.
-    @type doc: LeapDocument
-
-    @return: The JSON serialization of the decrypted content.
-    @rtype: str
-    """
-    soledad_assert(doc.is_tombstone() is False)
-    soledad_assert(ENC_JSON_KEY in doc.content)
-    soledad_assert(ENC_SCHEME_KEY in doc.content)
-    soledad_assert(ENC_METHOD_KEY in doc.content)
-    soledad_assert(MAC_KEY in doc.content)
-    soledad_assert(MAC_METHOD_KEY in doc.content)
-    # verify MAC
-    ciphertext = binascii.a2b_hex(  # content is stored as hex.
-        doc.content[ENC_JSON_KEY])
-    mac = mac_doc(
-        crypto, doc.doc_id, doc.rev,
-        ciphertext,
-        doc.content[MAC_METHOD_KEY])
-    if binascii.a2b_hex(doc.content[MAC_KEY]) != mac:  # mac is stored as hex.
-        raise WrongMac('Could not authenticate document\'s contents.')
-    # decrypt doc's content
-    enc_scheme = doc.content[ENC_SCHEME_KEY]
-    plainjson = None
-    if enc_scheme == EncryptionSchemes.SYMKEY:
-        enc_method = doc.content[ENC_METHOD_KEY]
-        if enc_method == EncryptionMethods.AES_256_CTR:
-            soledad_assert(ENC_IV_KEY in doc.content)
-            plainjson = crypto.decrypt_sym(
-                ciphertext,
-                crypto.doc_passphrase(doc.doc_id),
-                method=enc_method,
-                iv=doc.content[ENC_IV_KEY])
-        else:
-            raise UnknownEncryptionMethod(enc_method)
-    else:
-        raise UnknownEncryptionScheme(enc_scheme)
-    return plainjson
-
-
-class LeapDocument(Document):
-    """
-    Encryptable and syncable document.
-
-    LEAP Documents can be flagged as syncable or not, so the replicas
-    might not sync every document.
-    """
-
-    def __init__(self, doc_id=None, rev=None, json='{}', has_conflicts=False,
-                 syncable=True):
-        """
-        Container for handling an encryptable document.
-
-        @param doc_id: The unique document identifier.
-        @type doc_id: str
-        @param rev: The revision identifier of the document.
-        @type rev: str
-        @param json: The JSON string for this document.
-        @type json: str
-        @param has_conflicts: Boolean indicating if this document has conflicts
-        @type has_conflicts: bool
-        @param syncable: Should this document be synced with remote replicas?
-        @type syncable: bool
-        """
-        Document.__init__(self, doc_id, rev, json, has_conflicts)
-        self._syncable = syncable
-
-    def _get_syncable(self):
-        """
-        Return whether this document is syncable.
-
-        @return: Is this document syncable?
-        @rtype: bool
-        """
-        return self._syncable
-
-    def _set_syncable(self, syncable=True):
-        """
-        Determine if this document should be synced with remote replicas.
-
-        @param syncable: Should this document be synced with remote replicas?
-        @type syncable: bool
-        """
-        self._syncable = syncable
-
-    syncable = property(
-        _get_syncable,
-        _set_syncable,
-        doc="Determine if document should be synced with server."
-    )
-
-    def _get_rev(self):
-        """
-        Get the document revision.
-
-        Returning the revision as string solves the following exception in
-        Twisted web:
-            exceptions.TypeError: Can only pass-through bytes on Python 2
-
-        @return: The document revision.
-        @rtype: str
-        """
-        if self._rev is None:
-            return None
-        return str(self._rev)
-
-    def _set_rev(self, rev):
-        """
-        Set document revision.
-
-        @param rev: The new document revision.
-        @type rev: bytes
-        """
-        self._rev = rev
-
-    rev = property(
-        _get_rev,
-        _set_rev,
-        doc="Wrapper to ensure `doc.rev` is always returned as bytes.")
-
-
-#
-# LeapSyncTarget
-#
-
-class LeapSyncTarget(HTTPSyncTarget, TokenBasedAuth):
-    """
-    A SyncTarget that encrypts data before sending and decrypts data after
-    receiving.
-    """
-
-    #
-    # Token auth methods.
-    #
-
-    def set_token_credentials(self, uuid, token):
-        """
-        Store given credentials so we can sign the request later.
-
-        @param uuid: The user's uuid.
-        @type uuid: str
-        @param token: The authentication token.
-        @type token: str
-        """
-        TokenBasedAuth.set_token_credentials(self, uuid, token)
-
-    def _sign_request(self, method, url_query, params):
-        """
-        Return an authorization header to be included in the HTTP request.
-
-        @param method: The HTTP method.
-        @type method: str
-        @param url_query: The URL query string.
-        @type url_query: str
-        @param params: A list with encoded query parameters.
-        @type param: list
-
-        @return: The Authorization header.
-        @rtype: list of tuple
-        """
-        return TokenBasedAuth._sign_request(self, method, url_query, params)
-
-    #
-    # Modified HTTPSyncTarget methods.
-    #
-
-    @staticmethod
-    def connect(url, crypto=None):
-        return LeapSyncTarget(url, crypto=crypto)
-
-    def __init__(self, url, creds=None, crypto=None):
-        """
-        Initialize the LeapSyncTarget.
-
-        @param url: The url of the target replica to sync with.
-        @type url: str
-        @param creds: optional dictionary giving credentials.
-            to authorize the operation with the server.
-        @type creds: dict
-        @param soledad: An instance of Soledad so we can encrypt/decrypt
-            document contents when syncing.
-        @type soledad: soledad.Soledad
-        """
-        HTTPSyncTarget.__init__(self, url, creds)
-        self._crypto = crypto
-
-    def _parse_sync_stream(self, data, return_doc_cb, ensure_callback=None):
-        """
-        Parse incoming synchronization stream and insert documents in the
-        local database.
-
-        If an incoming document's encryption scheme is equal to
-        EncryptionSchemes.SYMKEY, then this method will decrypt it with
-        Soledad's symmetric key.
-
-        @param data: The body of the HTTP response.
-        @type data: str
-        @param return_doc_cb: A callback to insert docs from target.
-        @type return_doc_cb: function
-        @param ensure_callback: A callback to ensure we have the correct
-            target_replica_uid, if it was just created.
-        @type ensure_callback: function
-
-        @raise BrokenSyncStream: If C{data} is malformed.
-
-        @return: A dictionary representing the first line of the response got
-            from remote replica.
-        @rtype: list of str
-        """
-        parts = data.splitlines()  # one at a time
-        if not parts or parts[0] != '[':
-            raise BrokenSyncStream
-        data = parts[1:-1]
-        comma = False
-        if data:
-            line, comma = utils.check_and_strip_comma(data[0])
-            res = json.loads(line)
-            if ensure_callback and 'replica_uid' in res:
-                ensure_callback(res['replica_uid'])
-            for entry in data[1:]:
-                if not comma:  # missing in between comma
-                    raise BrokenSyncStream
-                line, comma = utils.check_and_strip_comma(entry)
-                entry = json.loads(line)
-                #-------------------------------------------------------------
-                # symmetric decryption of document's contents
-                #-------------------------------------------------------------
-                # if arriving content was symmetrically encrypted, we decrypt
-                # it.
-                doc = LeapDocument(entry['id'], entry['rev'], entry['content'])
-                if doc.content and ENC_SCHEME_KEY in doc.content:
-                    if doc.content[ENC_SCHEME_KEY] == \
-                            EncryptionSchemes.SYMKEY:
-                        doc.set_json(decrypt_doc(self._crypto, doc))
-                #-------------------------------------------------------------
-                # end of symmetric decryption
-                #-------------------------------------------------------------
-                return_doc_cb(doc, entry['gen'], entry['trans_id'])
-        if parts[-1] != ']':
-            try:
-                partdic = json.loads(parts[-1])
-            except ValueError:
-                pass
-            else:
-                if isinstance(partdic, dict):
-                    self._error(partdic)
-            raise BrokenSyncStream
-        if not data or comma:  # no entries or bad extra comma
-            raise BrokenSyncStream
-        return res
-
-    def sync_exchange(self, docs_by_generations, source_replica_uid,
-                      last_known_generation, last_known_trans_id,
-                      return_doc_cb, ensure_callback=None):
-        """
-        Find out which documents the remote database does not know about,
-        encrypt and send them.
-
-        This does the same as the parent's method but encrypts content before
-        syncing.
-
-        @param docs_by_generations: A list of (doc_id, generation, trans_id)
-            of local documents that were changed since the last local
-            generation the remote replica knows about.
-        @type docs_by_generations: list of tuples
-        @param source_replica_uid: The uid of the source replica.
-        @type source_replica_uid: str
-        @param last_known_generation: Target's last known generation.
-        @type last_known_generation: int
-        @param last_known_trans_id: Target's last known transaction id.
-        @type last_known_trans_id: str
-        @param return_doc_cb: A callback for inserting received documents from
-            target.
-        @type return_doc_cb: function
-        @param ensure_callback: A callback that ensures we know the target
-            replica uid if the target replica was just created.
-        @type ensure_callback: function
-
-        @return: The new generation and transaction id of the target replica.
-        @rtype: tuple
-        """
-        self._ensure_connection()
-        if self._trace_hook:  # for tests
-            self._trace_hook('sync_exchange')
-        url = '%s/sync-from/%s' % (self._url.path, source_replica_uid)
-        self._conn.putrequest('POST', url)
-        self._conn.putheader('content-type', 'application/x-u1db-sync-stream')
-        for header_name, header_value in self._sign_request('POST', url, {}):
-            self._conn.putheader(header_name, header_value)
-        entries = ['[']
-        size = 1
-
-        def prepare(**dic):
-            entry = comma + '\r\n' + json.dumps(dic)
-            entries.append(entry)
-            return len(entry)
-
-        comma = ''
-        size += prepare(
-            last_known_generation=last_known_generation,
-            last_known_trans_id=last_known_trans_id,
-            ensure=ensure_callback is not None)
-        comma = ','
-        for doc, gen, trans_id in docs_by_generations:
-            # skip non-syncable docs
-            if isinstance(doc, LeapDocument) and not doc.syncable:
-                continue
-            #-------------------------------------------------------------
-            # symmetric encryption of document's contents
-            #-------------------------------------------------------------
-            doc_json = doc.get_json()
-            if not doc.is_tombstone():
-                doc_json = encrypt_doc(self._crypto, doc)
-            #-------------------------------------------------------------
-            # end of symmetric encryption
-            #-------------------------------------------------------------
-            size += prepare(id=doc.doc_id, rev=doc.rev,
-                            content=doc_json,
-                            gen=gen, trans_id=trans_id)
-        entries.append('\r\n]')
-        size += len(entries[-1])
-        self._conn.putheader('content-length', str(size))
-        self._conn.endheaders()
-        for entry in entries:
-            self._conn.send(entry)
-        entries = None
-        data, _ = self._response()
-        res = self._parse_sync_stream(data, return_doc_cb, ensure_callback)
-        data = None
-        return res['new_generation'], res['new_transaction_id']