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|
try:
import simplejson as json
except ImportError:
import json # noqa
from u1db import Document
from u1db.remote.http_target import HTTPSyncTarget
from u1db.remote.http_database import HTTPDatabase
import base64
class NoDefaultKey(Exception):
pass
class LeapDocument(Document):
"""
LEAP Documents are standard u1db documents with cabability of returning an
encrypted version of the document json string as well as setting document
content based on an encrypted version of json string.
"""
def __init__(self, doc_id=None, rev=None, json='{}', has_conflicts=False,
encrypted_json=None, default_key=None, gpg_wrapper=None):
super(LeapDocument, self).__init__(doc_id, rev, json, has_conflicts)
if gpg_wrapper:
self._gpg = gpg_wrapper
else:
self._gpg = GPGWrapper()
if encrypted_json:
self.set_encrypted_json(encrypted_json)
self._default_key = default_key
def get_encrypted_json(self):
"""
Returns document's json serialization encrypted with user's public key.
"""
if self._default_key is None:
raise NoDefaultKey()
cyphertext = self._gpg.encrypt(self.get_json(),
self._default_key,
always_trust = True)
# TODO: always trust?
return json.dumps({'cyphertext' : str(cyphertext)})
def set_encrypted_json(self, encrypted_json):
"""
Set document's content based on encrypted version of json string.
"""
cyphertext = json.loads(encrypted_json)['cyphertext']
plaintext = str(self._gpg.decrypt(cyphertext))
return self.set_json(plaintext)
class LeapDatabase(HTTPDatabase):
"""Implement the HTTP remote database API to a Leap server."""
@staticmethod
def open_database(url, create):
db = LeapDatabase(url)
db.open(create)
return db
@staticmethod
def delete_database(url):
db = LeapDatabase(url)
db._delete()
db.close()
def get_sync_target(self):
st = LeapSyncTarget(self._url.geturl())
st._creds = self._creds
return st
class LeapSyncTarget(HTTPSyncTarget):
def _parse_sync_stream(self, data, return_doc_cb, ensure_callback=None):
"""
Does the same as parent's method but ensures incoming content will be
decrypted.
"""
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)
doc = LeapDocument(entry['id'], entry['rev'],
encrypted_json=entry['content'])
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):
"""
Does the same as parent's method but encrypts content before syncing.
"""
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:
size += prepare(id=doc.doc_id, rev=doc.rev,
content=doc.get_encrypted_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']
|
