Fix symmetric encryption when syncing.

Also does:

  * Remove all crypto methods from LeapDocument.
  * Encode 'encryption_scheme' inside the document JSON.
  * Add functions for encrypting and decrypting.
  * Fix LeapSyncTarget so its connection actually returns a LeapSyncTarget.
  * Fix symmetric encryption when syncing:
    - don't try to encrypt tombstone documents.
  * Fix symmetric decryption when syncing:
    - Only try do decrypt if the incoming document has an '_encryption_scheme'
      entry with value equal to EncryptionSchemes.PUBKEY.
  * Fix doc skipping for non-syncable docs.
  * Fix tests that compared raw content with encrypted content.

8 files changed, 506 insertions, 236 deletions

diff --git a/src/leap/soledad/__init__.py b/src/leap/soledad/__init__.py
index 78888ead..a736d32b 100644
--- a/src/leap/soledad/__init__.py
+++ b/src/leap/soledad/__init__.py
@@ -421,8 +421,7 @@ class Soledad(object):
             content = {
                 '_symkey': self.encrypt_sym(self._symkey, self._passphrase),
             }
-            doc = LeapDocument(doc_id=self._address_hash(),
-                               crypto=self._crypto)
+            doc = LeapDocument(doc_id=self._address_hash())
             doc.content = content
             self._shared_db.put_doc(doc)
             events.signal(
diff --git a/src/leap/soledad/backends/couch.py b/src/leap/soledad/backends/couch.py
index 13b6733c..ad8d10e3 100644
--- a/src/leap/soledad/backends/couch.py
+++ b/src/leap/soledad/backends/couch.py
@@ -144,8 +144,7 @@ class CouchDatabase(ObjectStoreDatabase):
         doc = self._factory(
             doc_id=doc_id,
             rev=cdoc['u1db_rev'],
-            has_conflicts=has_conflicts,
-            encryption_scheme=cdoc['encryption_scheme'])
+            has_conflicts=has_conflicts)
         contents = self._database.get_attachment(cdoc, 'u1db_json')
         if contents:
             doc.content = json.loads(contents.read())
@@ -201,8 +200,6 @@ class CouchDatabase(ObjectStoreDatabase):
             cdoc['_rev'] = old_cdoc['_rev']
         # store u1db's rev
         cdoc['u1db_rev'] = doc.rev
-        # store document's encryption scheme
-        cdoc['encryption_scheme'] = doc.encryption_scheme
         # save doc in db
         self._database.save(cdoc)
         # store u1db's content as json string
diff --git a/src/leap/soledad/backends/leap_backend.py b/src/leap/soledad/backends/leap_backend.py
index 1c0d5a7d..05c27bc1 100644
--- a/src/leap/soledad/backends/leap_backend.py
+++ b/src/leap/soledad/backends/leap_backend.py
@@ -36,6 +36,7 @@ from u1db.errors import BrokenSyncStream
 
 
 from leap.common.keymanager import KeyManager
+from leap.common.check import leap_assert
 
 
 class NoDefaultKey(Exception):
@@ -59,6 +60,16 @@ class DocumentNotEncrypted(Exception):
     pass
 
 
+class UnknownEncryptionSchemes(Exception):
+    """
+    Raised when trying to decrypt from unknown encryption schemes.
+    """
+
+
+#
+# Encryption schemes used for encryption.
+#
+
 class EncryptionSchemes(object):
     """
     Representation of encryption schemes used to encrypt documents.
@@ -69,21 +80,103 @@ class EncryptionSchemes(object):
     PUBKEY = 'pubkey'
 
 
+#
+# Crypto utilities for a LeapDocument.
+#
+
+def encrypt_doc_json(crypto, doc_id, doc_json):
+    """
+    Return a valid JSON string containing the C{doc} content encrypted to
+    a symmetric key and the encryption scheme.
+
+    The returned JSON string is the serialization of the following dictionary:
+
+        {
+            '_encrypted_json': encrypt_sym(doc_content),
+            '_encryption_scheme: 'symkey',
+        }
+
+    @param crypto: A SoledadCryto instance to perform the encryption.
+    @type crypto: leap.soledad.crypto.SoledadCrypto
+    @param doc_id: The unique id of the document.
+    @type doc_id: str
+    @param doc_json: The JSON serialization of the document's contents.
+    @type doc_json: str
+
+    @return: The JSON serialization representing the encrypted content.
+    @rtype: str
+    """
+    ciphertext = crypto.encrypt_sym(
+        doc_json,
+        crypto.passphrase_hash(doc_id))
+    if not crypto.is_encrypted_sym(ciphertext):
+        raise DocumentNotEncrypted('Failed encrypting document.')
+    return json.dumps({
+        '_encrypted_json': ciphertext,
+        '_encryption_scheme': EncryptionSchemes.SYMKEY,
+    })
+
+
+def decrypt_doc_json(crypto, doc_id, doc_json):
+    """
+    Return a JSON serialization of the decrypted content contained in
+    C{encrypted_json}.
+
+    The C{encrypted_json} parameter is the JSON serialization of the
+    following dictionary:
+
+        {
+            '_encrypted_json': enc_blob,
+            '_encryption_scheme': enc_scheme,
+        }
+
+    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.
+
+    @param crypto: A SoledadCryto instance to perform the encryption.
+    @type crypto: leap.soledad.crypto.SoledadCrypto
+    @param doc_id: The unique id of the document.
+    @type doc_id: str
+    @param doc_json: The JSON serialization representation of the encrypted
+        document's contents.
+    @type doc_json: str
+
+    @return: The JSON serialization of the decrypted content.
+    @rtype: str
+    """
+    leap_assert(isinstance(doc_id, str))
+    leap_assert(doc_id != '')
+    leap_assert(isinstance(doc_json, str))
+    leap_assert(doc_json != '')
+    content = json.loads(doc_json)
+    ciphertext = content['_encrypted_json']
+    enc_scheme = content['_encryption_scheme']
+    plainjson = None
+    if enc_scheme == EncryptionSchemes.SYMKEY:
+        if not crypto.is_encrypted_sym(ciphertext):
+            raise DocumentNotEncrypted(
+                'Unable to identify document encryption for incoming '
+                'document, although it is marked as being encrypted with a '
+                'symmetric key.')
+        plainjson = crypto.decrypt_sym(
+            ciphertext,
+            crypto.passphrase_hash(doc_id))
+    else:
+        raise UnknownEncryptionScheme(enc_scheme)
+    return plainjson
+
+
 class LeapDocument(Document):
     """
     Encryptable and syncable 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.
-
-    Also, LEAP Documents can be flagged as syncable or not, so the replicas
+    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,
-                 encrypted_json=None, crypto=None, syncable=True,
-                 encryption_scheme=EncryptionSchemes.NONE):
+                 syncable=True):
         """
         Container for handling an encryptable document.
 
@@ -95,68 +188,11 @@ class LeapDocument(Document):
         @type json: str
         @param has_conflicts: Boolean indicating if this document has conflicts
         @type has_conflicts: bool
-        @param encrypted_json: The encrypted JSON string for this document. If
-            given, the decrypted value supersedes any raw json string given.
-        @type encrypted_json: str
-        @param crypto: An instance of SoledadCrypto so we can encrypt/decrypt
-            document contents when syncing.
-        @type crypto: soledad.Soledad
         @param syncable: Should this document be synced with remote replicas?
         @type syncable: bool
-        @param encryption_scheme: The encryption scheme for this objects'
-            contents.
-        @type encryption_scheme: str
         """
         Document.__init__(self, doc_id, rev, json, has_conflicts)
-        self._crypto = crypto
         self._syncable = syncable
-        self._encryption_scheme = encryption_scheme
-        if encrypted_json:
-            self.set_encrypted_json(encrypted_json)
-
-    def get_encrypted_content(self):
-        """
-        Return an encrypted JSON serialization of document's contents.
-
-        @return: The encrypted JSON serialization of document's contents.
-        @rtype: str
-        """
-        if not self._crypto:
-            raise NoSoledadCryptoInstance()
-        return self._crypto.encrypt_sym(
-            self.get_json(),
-            self._crypto.passphrase_hash(self.doc_id))
-
-    def set_encrypted_content(self, cyphertext):
-        """
-        Decrypt C{cyphertext} and set document's content.
-        contents.
-        """
-        plaintext = self._crypto.decrypt_sym(
-            cyphertext,
-            self._crypto.passphrase_hash(self.doc_id))
-        self.set_json(plaintext)
-        self.encryption_scheme = EncryptionSchemes.NONE
-
-    def get_encrypted_json(self):
-        """
-        Return a valid JSON string containing document's content encrypted to
-        the user's public key.
-
-        @return: The encrypted JSON string.
-        @rtype: str
-        """
-        return json.dumps({'_encrypted_json': self.get_encrypted_content()})
-
-    def set_encrypted_json(self, encrypted_json):
-        """
-        Set document's content based on a valid JSON string containing the
-        encrypted document's contents.
-        """
-        if not self._crypto:
-            raise NoSoledadCryptoInstance()
-        cyphertext = json.loads(encrypted_json)['_encrypted_json']
-        self.set_encrypted_content(cyphertext)
 
     def _get_syncable(self):
         """
@@ -182,31 +218,6 @@ class LeapDocument(Document):
         doc="Determine if document should be synced with server."
     )
 
-    def _get_encryption_scheme(self):
-        """
-        Return the encryption scheme used to encrypt this document's contents.
-
-        @return: The encryption scheme used to encrypt this document's
-            contents.
-        @rtype: str
-        """
-        return self._encryption_scheme
-
-    def _set_encryption_scheme(self, encryption_scheme=True):
-        """
-        Set the encryption scheme used to encrypt this document's contents.
-
-        @param encryption_scheme: The encryption scheme.
-        @type encryption_scheme: str
-        """
-        self._encryption_scheme = encryption_scheme
-
-    encryption_scheme = property(
-        _get_encryption_scheme,
-        _set_encryption_scheme,
-        doc="The encryption scheme used to encrypt this document's contents."
-    )
-
     def _get_rev(self):
         """
         Get the document revision.
@@ -237,12 +248,20 @@ class LeapDocument(Document):
         doc="Wrapper to ensure `doc.rev` is always returned as bytes.")
 
 
+#
+# LeapSyncTarget
+#
+
 class LeapSyncTarget(HTTPSyncTarget):
     """
     A SyncTarget that encrypts data before sending and decrypts data after
     receiving.
     """
 
+    @staticmethod
+    def connect(url, crypto=None):
+        return LeapSyncTarget(url, crypto=crypto)
+
     def __init__(self, url, creds=None, crypto=None):
         """
         Initialize the LeapSyncTarget.
@@ -290,34 +309,21 @@ class LeapSyncTarget(HTTPSyncTarget):
                     raise BrokenSyncStream
                 line, comma = utils.check_and_strip_comma(entry)
                 entry = json.loads(line)
-                # decrypt after receiving from server.
-                if not self._crypto:
-                    raise NoSoledadCryptoInstance()
-                # all content arriving should be encrypted either with the
-                # user's symmetric key or with the user's public key.
-                enc_json = json.loads(entry['content'])['_encrypted_json']
-                plain_json = None
-                if entry['encryption_scheme'] == EncryptionScheme.SYMKEY:
-                    if not self._crypto.is_encrypted_sym(enc_json):
-                        raise DocumentNotEncrypted(
-                            'Incoming document\'s contents should be '
-                            'encrypted with a symmetric key.')
-                    plain_json = self._crypto.decrypt_sym(
-                        enc_json, self._crypto._symkey)
-                elif entry['encryption_scheme'] == EncryptionScheme.PUBKEY:
-                    if not self._crypto.is_encrypted_asym(enc_json):
-                        raise DocumentNotEncrypted(
-                            'Incoming document\'s contents should be '
-                            'encrypted to the user\'s public key.')
-                    plain_json = self._crypto.decrypt_asym(enc_json)
-                else:
-                    raise DocumentNotEncrypted(
-                        "Incoming document from sync is not encrypted.")
-                # if decryption was OK, then create the document.
-                doc = LeapDocument(entry['id'], entry['rev'],
-                                   json=plain_json,
-                                   crypto=self._crypto,
-                                   encryption_scheme=EncryptionScheme.NONE)
+                #-------------------------------------------------------------
+                # 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 '_encryption_scheme' in doc.content:
+                    if doc.content['_encryption_scheme'] == \
+                            EncryptionSchemes.SYMKEY:
+                        doc.set_json(
+                            decrypt_doc_json(
+                                self._crypto, doc.doc_id, entry['content']))
+                #-------------------------------------------------------------
+                # end of symmetric decryption
+                #-------------------------------------------------------------
                 return_doc_cb(doc, entry['gen'], entry['trans_id'])
         if parts[-1] != ']':
             try:
@@ -361,17 +367,22 @@ class LeapSyncTarget(HTTPSyncTarget):
             ensure=ensure_callback is not None)
         comma = ','
         for doc, gen, trans_id in docs_by_generations:
-            if doc.syncable:
-                # encrypt and verify before sending to server.
-                enc_json = json.loads(
-                    doc.get_encrypted_json())['_encrypted_json']
-                if not self._crypto.is_encrypted_sym(enc_json):
-                    raise DocumentNotEncrypted(
-                        "Could not encrypt document before sync.")
-                size += prepare(id=doc.doc_id, rev=doc.rev,
-                                content=enc_json,
-                                gen=gen, trans_id=trans_id,
-                                encryption_scheme=EncryptionSchemes.SYMKEY)
+            # skip non-syncable docs
+            if isinstance(doc, LeapDocument) and not doc.syncable:
+                continue
+            #-------------------------------------------------------------
+            # symmetric encryption of document's contents
+            #-------------------------------------------------------------
+            enc_json = doc.get_json()
+            if not doc.is_tombstone():
+                enc_json = encrypt_doc_json(
+                    self._crypto, doc.doc_id, doc.get_json())
+            #-------------------------------------------------------------
+            # end of symmetric encryption
+            #-------------------------------------------------------------
+            size += prepare(id=doc.doc_id, rev=doc.rev,
+                            content=enc_json,
+                            gen=gen, trans_id=trans_id)
         entries.append('\r\n]')
         size += len(entries[-1])
         self._conn.putheader('content-length', str(size))
diff --git a/src/leap/soledad/backends/sqlcipher.py b/src/leap/soledad/backends/sqlcipher.py
index fb5c3e79..f840d809 100644
--- a/src/leap/soledad/backends/sqlcipher.py
+++ b/src/leap/soledad/backends/sqlcipher.py
@@ -100,14 +100,10 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase):
         self._crypto = crypto
 
         def factory(doc_id=None, rev=None, json='{}', has_conflicts=False,
-                    encrypted_json=None, syncable=True,
-                    encryption_scheme=EncryptionSchemes.NONE):
+                    syncable=True):
             return LeapDocument(doc_id=doc_id, rev=rev, json=json,
                                 has_conflicts=has_conflicts,
-                                encrypted_json=encrypted_json,
-                                crypto=self._crypto,
-                                syncable=syncable,
-                                encryption_scheme=encryption_scheme)
+                                syncable=syncable)
         self.set_document_factory(factory)
 
     def _check_if_db_is_encrypted(self, sqlcipher_file):
@@ -248,10 +244,6 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase):
         c.execute(
             'ALTER TABLE document '
             'ADD COLUMN syncable BOOL NOT NULL DEFAULT TRUE')
-        c.execute(
-            'ALTER TABLE document '
-            'ADD COLUMN encryption_scheme TEXT NOT NULL DEFAULT \'%s\'' %
-            EncryptionSchemes.NONE)
 
     def _put_and_update_indexes(self, old_doc, doc):
         """
@@ -265,9 +257,9 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase):
         sqlite_backend.SQLitePartialExpandDatabase._put_and_update_indexes(
             self, old_doc, doc)
         c = self._db_handle.cursor()
-        c.execute('UPDATE document SET syncable=?, encryption_scheme=? '
+        c.execute('UPDATE document SET syncable=? '
                   'WHERE doc_id=?',
-                  (doc.syncable, doc.encryption_scheme, doc.doc_id))
+                  (doc.syncable, doc.doc_id))
 
     def _get_doc(self, doc_id, check_for_conflicts=False):
         """
@@ -287,12 +279,11 @@ class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase):
             self, doc_id, check_for_conflicts)
         if doc:
             c = self._db_handle.cursor()
-            c.execute('SELECT syncable, encryption_scheme FROM document '
+            c.execute('SELECT syncable FROM document '
                       'WHERE doc_id=?',
                       (doc.doc_id,))
             result = c.fetchone()
             doc.syncable = bool(result[0])
-            doc.encryption_scheme = result[1]
         return doc
 
 sqlite_backend.SQLiteDatabase.register_implementation(SQLCipherDatabase)
diff --git a/src/leap/soledad/tests/test_couch.py b/src/leap/soledad/tests/test_couch.py
index cdf9c9ff..456bc080 100644
--- a/src/leap/soledad/tests/test_couch.py
+++ b/src/leap/soledad/tests/test_couch.py
@@ -17,7 +17,6 @@ except ImportError:
     import json  # noqa
 from leap.soledad.backends.leap_backend import (
     LeapDocument,
-    EncryptionSchemes,
 )
 
 
@@ -412,30 +411,5 @@ class CouchDatabaseStorageTests(CouchDBTestCase):
         content = self._fetch_u1db_data(db)
         self.assertEqual(db._replica_uid, content['replica_uid'])
 
-    def test_store_encryption_scheme(self):
-        db = couch.CouchDatabase('http://localhost:' + str(self.wrapper.port),
-                                 'u1db_tests')
-        doc = db.create_doc_from_json(tests.simple_doc)
-        # assert that docs have no encryption_scheme by default
-        self.assertEqual(EncryptionSchemes.NONE, doc.encryption_scheme)
-        # assert that we can store a different value
-        doc.encryption_scheme = EncryptionSchemes.PUBKEY
-        db.put_doc(doc)
-        self.assertEqual(
-            EncryptionSchemes.PUBKEY,
-            db.get_doc(doc.doc_id).encryption_scheme)
-        # assert that we can store another different value
-        doc.encryption_scheme = EncryptionSchemes.SYMKEY
-        db.put_doc(doc)
-        self.assertEqual(
-            EncryptionSchemes.SYMKEY,
-            db.get_doc(doc.doc_id).encryption_scheme)
-        # assert that we can store the default value
-        doc.encryption_scheme = EncryptionSchemes.NONE
-        db.put_doc(doc)
-        self.assertEqual(
-            EncryptionSchemes.NONE,
-            db.get_doc(doc.doc_id).encryption_scheme)
-
 
 load_tests = tests.load_with_scenarios
diff --git a/src/leap/soledad/tests/test_crypto.py b/src/leap/soledad/tests/test_crypto.py
index 039d2f3c..676c13b0 100644
--- a/src/leap/soledad/tests/test_crypto.py
+++ b/src/leap/soledad/tests/test_crypto.py
@@ -22,22 +22,26 @@ Tests for cryptographic related stuff.
 
 
 import os
+try:
+    import simplejson as json
+except ImportError:
+    import json  # noqa
 
 
+from leap.soledad.backends.leap_backend import (
+    LeapDocument,
+    encrypt_doc_json,
+    decrypt_doc_json,
+    EncryptionSchemes,
+)
+from leap.soledad import KeyAlreadyExists
+from leap.soledad.crypto import SoledadCrypto
 from leap.common.testing.basetest import BaseLeapTest
-from leap.soledad.backends.leap_backend import LeapDocument
 from leap.soledad.tests import BaseSoledadTest
 from leap.soledad.tests import (
     KEY_FINGERPRINT,
     PRIVATE_KEY,
 )
-from leap.soledad import KeyAlreadyExists
-from leap.soledad.crypto import SoledadCrypto
-
-try:
-    import simplejson as json
-except ImportError:
-    import json  # noqa
 
 
 class EncryptedSyncTestCase(BaseSoledadTest):
@@ -45,26 +49,31 @@ class EncryptedSyncTestCase(BaseSoledadTest):
     Tests that guarantee that data will always be encrypted when syncing.
     """
 
-    def test_get_set_encrypted_json(self):
+    def test_encrypt_decrypt_json(self):
         """
-        Test getting and setting encrypted content.
+        Test encrypting and decrypting documents.
         """
-        doc1 = LeapDocument(crypto=self._soledad._crypto)
+        doc1 = LeapDocument(doc_id='id')
         doc1.content = {'key': 'val'}
-        doc2 = LeapDocument(doc_id=doc1.doc_id,
-                            encrypted_json=doc1.get_encrypted_json(),
-                            crypto=self._soledad._crypto)
+        enc_json = encrypt_doc_json(
+            self._soledad._crypto, doc1.doc_id, doc1.get_json())
+        plain_json = decrypt_doc_json(
+            self._soledad._crypto, doc1.doc_id, enc_json)
+        doc2 = LeapDocument(doc_id=doc1.doc_id, json=plain_json)
         res1 = doc1.get_json()
         res2 = doc2.get_json()
         self.assertEqual(res1, res2, 'incorrect document encryption')
 
-    def test_successful_symmetric_encryption(self):
+    def test_encrypt_sym(self):
         """
         Test for successful symmetric encryption.
         """
-        doc1 = LeapDocument(crypto=self._soledad._crypto)
+        doc1 = LeapDocument()
         doc1.content = {'key': 'val'}
-        enc_json = json.loads(doc1.get_encrypted_json())['_encrypted_json']
+        enc_json = json.loads(
+            encrypt_doc_json(
+                self._soledad._crypto,
+                doc1.doc_id, doc1.get_json()))['_encrypted_json']
         self.assertEqual(
             True,
             self._soledad._crypto.is_encrypted_sym(enc_json),
diff --git a/src/leap/soledad/tests/test_leap_backend.py b/src/leap/soledad/tests/test_leap_backend.py
index 0bf70f9e..7509af0e 100644
--- a/src/leap/soledad/tests/test_leap_backend.py
+++ b/src/leap/soledad/tests/test_leap_backend.py
@@ -5,6 +5,10 @@ For these tests to run, a leap server has to be running on (default) port
 """
 
 import u1db
+try:
+    import simplejson as json
+except ImportError:
+    import json  # noqa
 
 
 from leap.soledad.backends import leap_backend
@@ -29,16 +33,7 @@ from leap.soledad.tests.u1db_tests import test_https
 def make_leap_document_for_test(test, doc_id, rev, content,
                                 has_conflicts=False):
     return leap_backend.LeapDocument(
-        doc_id, rev, content, has_conflicts=has_conflicts,
-        crypto=test._soledad._crypto)
-
-
-def make_leap_encrypted_document_for_test(test, doc_id, rev, encrypted_content,
-                                          has_conflicts=False):
-    return leap_backend.LeapDocument(
-        doc_id, rev, encrypted_json=encrypted_content,
-        has_conflicts=has_conflicts,
-        crypto=test._soledad.crypto)
+        doc_id, rev, content, has_conflicts=has_conflicts)
 
 
 LEAP_SCENARIOS = [
@@ -94,9 +89,22 @@ class TestLeapSyncTargetBasics(
         self.assertEqual('/', remote_target._url.path)
 
 
-class TestLeapParsingSyncStream(test_remote_sync_target.TestParsingSyncStream):
+class TestLeapParsingSyncStream(
+        test_remote_sync_target.TestParsingSyncStream,
+        BaseSoledadTest):
+
+    def setUp(self):
+        test_remote_sync_target.TestParsingSyncStream.setUp(self)
+        BaseSoledadTest.setUp(self)
+
+    def tearDown(self):
+        test_remote_sync_target.TestParsingSyncStream.tearDown(self)
+        BaseSoledadTest.tearDown(self)
 
     def test_wrong_start(self):
+        """
+        Test adapted to use a LeapSyncTarget.
+        """
         tgt = leap_backend.LeapSyncTarget("http://foo/foo")
 
         self.assertRaises(u1db.errors.BrokenSyncStream,
@@ -109,6 +117,9 @@ class TestLeapParsingSyncStream(test_remote_sync_target.TestParsingSyncStream):
                           tgt._parse_sync_stream, "", None)
 
     def test_wrong_end(self):
+        """
+        Test adapted to use a LeapSyncTarget.
+        """
         tgt = leap_backend.LeapSyncTarget("http://foo/foo")
 
         self.assertRaises(u1db.errors.BrokenSyncStream,
@@ -118,6 +129,9 @@ class TestLeapParsingSyncStream(test_remote_sync_target.TestParsingSyncStream):
                           tgt._parse_sync_stream, "[\r\n", None)
 
     def test_missing_comma(self):
+        """
+        Test adapted to use a LeapSyncTarget.
+        """
         tgt = leap_backend.LeapSyncTarget("http://foo/foo")
 
         self.assertRaises(u1db.errors.BrokenSyncStream,
@@ -126,21 +140,32 @@ class TestLeapParsingSyncStream(test_remote_sync_target.TestParsingSyncStream):
                           '"content": "c", "gen": 3}\r\n]', None)
 
     def test_no_entries(self):
+        """
+        Test adapted to use a LeapSyncTarget.
+        """
         tgt = leap_backend.LeapSyncTarget("http://foo/foo")
 
         self.assertRaises(u1db.errors.BrokenSyncStream,
                           tgt._parse_sync_stream, "[\r\n]", None)
 
     def test_extra_comma(self):
-        tgt = leap_backend.LeapSyncTarget("http://foo/foo")
+        """
+        Test adapted to use encrypted content.
+        """
+        doc = leap_backend.LeapDocument('i')
+        doc.content = {}
+        enc_json = leap_backend.encrypt_doc_json(
+            self._soledad._crypto, doc.doc_id, doc.get_json())
+        tgt = leap_backend.LeapSyncTarget(
+            "http://foo/foo", crypto=self._soledad._crypto)
 
         self.assertRaises(u1db.errors.BrokenSyncStream,
                           tgt._parse_sync_stream, "[\r\n{},\r\n]", None)
-        self.assertRaises(leap_backend.NoSoledadCryptoInstance,
+        self.assertRaises(u1db.errors.BrokenSyncStream,
                           tgt._parse_sync_stream,
                           '[\r\n{},\r\n{"id": "i", "rev": "r", '
-                          '"content": "{}", "gen": 3, "trans_id": "T-sid"}'
-                          ',\r\n]',
+                          '"content": %s, "gen": 3, "trans_id": "T-sid"}'
+                          ',\r\n]' % json.dumps(enc_json),
                           lambda doc, gen, trans_id: None)
 
     def test_error_in_stream(self):
diff --git a/src/leap/soledad/tests/test_sqlcipher.py b/src/leap/soledad/tests/test_sqlcipher.py
index 337ab4ee..73388202 100644
--- a/src/leap/soledad/tests/test_sqlcipher.py
+++ b/src/leap/soledad/tests/test_sqlcipher.py
@@ -2,16 +2,21 @@
 
 import os
 import time
-from pysqlcipher import dbapi2
 import unittest
-from StringIO import StringIO
+try:
+    import simplejson as json
+except ImportError:
+    import json  # noqa
 import threading
+from pysqlcipher import dbapi2
+from StringIO import StringIO
 
 # u1db stuff.
 from u1db import (
     errors,
     query_parser,
     sync,
+    vectorclock,
 )
 from u1db.backends.sqlite_backend import SQLitePartialExpandDatabase
 
@@ -24,10 +29,12 @@ from leap.soledad.backends.sqlcipher import open as u1db_open
 from leap.soledad.backends.leap_backend import (
     LeapDocument,
     EncryptionSchemes,
+    decrypt_doc_json,
+    encrypt_doc_json,
 )
 
 # u1db tests stuff.
-from leap.soledad.tests import u1db_tests as tests
+from leap.soledad.tests import u1db_tests as tests, BaseSoledadTest
 from leap.soledad.tests.u1db_tests import test_sqlite_backend
 from leap.soledad.tests.u1db_tests import test_backends
 from leap.soledad.tests.u1db_tests import test_open
@@ -345,29 +352,6 @@ class TestSQLCipherPartialExpandDatabase(
         self.db.put_doc(doc)
         self.assertEqual(True, self.db.get_doc(doc.doc_id).syncable)
 
-    def test_store_encryption_scheme(self):
-        doc = self.db.create_doc_from_json(tests.simple_doc)
-        # assert that docs have no encryption_scheme by default
-        self.assertEqual(EncryptionSchemes.NONE, doc.encryption_scheme)
-        # assert that we can store a different value
-        doc.encryption_scheme = EncryptionSchemes.PUBKEY
-        self.db.put_doc(doc)
-        self.assertEqual(
-            EncryptionSchemes.PUBKEY,
-            self.db.get_doc(doc.doc_id).encryption_scheme)
-        # assert that we can store another different value
-        doc.encryption_scheme = EncryptionSchemes.SYMKEY
-        self.db.put_doc(doc)
-        self.assertEqual(
-            EncryptionSchemes.SYMKEY,
-            self.db.get_doc(doc.doc_id).encryption_scheme)
-        # assert that we can store the default value
-        doc.encryption_scheme = EncryptionSchemes.NONE
-        self.db.put_doc(doc)
-        self.assertEqual(
-            EncryptionSchemes.NONE,
-            self.db.get_doc(doc.doc_id).encryption_scheme)
-
 
 #-----------------------------------------------------------------------------
 # The following tests come from `u1db.tests.test_open`.
@@ -430,7 +414,7 @@ def sync_via_synchronizer_and_leap(test, db_source, db_target,
     if trace_hook:
         test.skipTest("full trace hook unsupported over http")
     path = test._http_at[db_target]
-    target = LeapSyncTarget.connect(test.getURL(path))
+    target = LeapSyncTarget.connect(test.getURL(path), test._soledad._crypto)
     if trace_hook_shallow:
         target._set_trace_hook_shallow(trace_hook_shallow)
     return sync.Synchronizer(db_source, target).sync()
@@ -445,15 +429,192 @@ sync_scenarios.append(('pyleap', {
 }))
 
 
-class SQLCipherDatabaseSyncTests(test_sync.DatabaseSyncTests):
+class SQLCipherDatabaseSyncTests(
+        test_sync.DatabaseSyncTests, BaseSoledadTest):
 
     scenarios = sync_scenarios
 
+    def setUp(self):
+        test_sync.DatabaseSyncTests.setUp(self)
+        BaseSoledadTest.setUp(self)
+
+    def tearDown(self):
+        test_sync.DatabaseSyncTests.tearDown(self)
+        BaseSoledadTest.tearDown(self)
+
+    def test_sync_autoresolves(self):
+        # The remote database can't autoresolve conflicts based on magic
+        # content convergence, so we modify this test to leave the possibility
+        # of the remode document ending up in conflicted state.
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        doc1 = self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc')
+        rev1 = doc1.rev
+        doc2 = self.db2.create_doc_from_json(tests.simple_doc, doc_id='doc')
+        rev2 = doc2.rev
+        self.sync(self.db1, self.db2)
+        doc = self.db1.get_doc('doc')
+        self.assertFalse(doc.has_conflicts)
+        # if remote content is in conflicted state, then document revisions
+        # will be different.
+        #self.assertEqual(doc.rev, self.db2.get_doc('doc').rev)
+        v = vectorclock.VectorClockRev(doc.rev)
+        self.assertTrue(v.is_newer(vectorclock.VectorClockRev(rev1)))
+        self.assertTrue(v.is_newer(vectorclock.VectorClockRev(rev2)))
+
+    def test_sync_autoresolves_moar(self):
+        # here we test that when a database that has a conflicted document is
+        # the source of a sync, and the target database has a revision of the
+        # conflicted document that is newer than the source database's, and
+        # that target's database's document's content is the same as the
+        # source's document's conflict's, the source's document's conflict gets
+        # autoresolved, and the source's document's revision bumped.
+        #
+        # idea is as follows:
+        # A          B
+        # a1         -
+        #   `------->
+        # a1         a1
+        # v          v
+        # a2         a1b1
+        #   `------->
+        # a1b1+a2    a1b1
+        #            v
+        # a1b1+a2    a1b2 (a1b2 has same content as a2)
+        #   `------->
+        # a3b2       a1b2 (autoresolved)
+        #   `------->
+        # a3b2       a3b2
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc')
+        self.sync(self.db1, self.db2)
+        for db, content in [(self.db1, '{}'), (self.db2, '{"hi": 42}')]:
+            doc = db.get_doc('doc')
+            doc.set_json(content)
+            db.put_doc(doc)
+        self.sync(self.db1, self.db2)
+        # db1 and db2 now both have a doc of {hi:42}, but db1 has a conflict
+        doc = self.db1.get_doc('doc')
+        rev1 = doc.rev
+        self.assertTrue(doc.has_conflicts)
+        # set db2 to have a doc of {} (same as db1 before the conflict)
+        doc = self.db2.get_doc('doc')
+        doc.set_json('{}')
+        self.db2.put_doc(doc)
+        rev2 = doc.rev
+        # sync it across
+        self.sync(self.db1, self.db2)
+        # tadaa!
+        doc = self.db1.get_doc('doc')
+        self.assertFalse(doc.has_conflicts)
+        vec1 = vectorclock.VectorClockRev(rev1)
+        vec2 = vectorclock.VectorClockRev(rev2)
+        vec3 = vectorclock.VectorClockRev(doc.rev)
+        self.assertTrue(vec3.is_newer(vec1))
+        self.assertTrue(vec3.is_newer(vec2))
+        # because the conflict is on the source, sync it another time
+        self.sync(self.db1, self.db2)
+        # make sure db2 now has the exact same thing
+        doc1 = self.db1.get_doc('doc')
+        doc2 = self.db1.get_doc('doc')
+        if '_encryption_scheme' in doc2.content:
+            doc2.set_json(
+                decrypt_doc_json(
+                    self._soledad._crypto, doc2, doc2.get_json()))
+        self.assertEqual(doc1, doc2)
+
+    def test_sync_autoresolves_moar_backwards(self):
+        # here we would test that when a database that has a conflicted
+        # document is the target of a sync, and the source database has a
+        # revision of the conflicted document that is newer than the target
+        # database's, and that source's database's document's content is the
+        # same as the target's document's conflict's, the target's document's
+        # conflict gets autoresolved, and the document's revision bumped.
+        #
+        # Despite that, in Soledad we suppose that the server never syncs, so
+        # it never has conflicted documents. Also, if it had, convergence
+        # would not be possible in terms of document's contents.
+        #
+        # Therefore we suppress this test.
+        pass
+
+    def test_sync_autoresolves_moar_backwards_three(self):
+        # We use the same reasoning from the last test to suppress this one.
+        pass
+
+    def test_sync_propagates_resolution(self):
+        self.db1 = self.create_database('test1', 'both')
+        self.db2 = self.create_database('test2', 'both')
+        doc1 = self.db1.create_doc_from_json('{"a": 1}', doc_id='the-doc')
+        db3 = self.create_database('test3', 'both')
+        self.sync(self.db2, self.db1)
+        self.assertEqual(
+            self.db1._get_generation_info(),
+            self.db2._get_replica_gen_and_trans_id(self.db1._replica_uid))
+        self.assertEqual(
+            self.db2._get_generation_info(),
+            self.db1._get_replica_gen_and_trans_id(self.db2._replica_uid))
+        self.sync(db3, self.db1)
+        # update on 2
+        doc2 = self.make_document('the-doc', doc1.rev, '{"a": 2}')
+        self.db2.put_doc(doc2)
+        self.sync(self.db2, db3)
+        self.assertEqual(db3.get_doc('the-doc').rev, doc2.rev)
+        # update on 1
+        doc1.set_json('{"a": 3}')
+        self.db1.put_doc(doc1)
+        # conflicts
+        self.sync(self.db2, self.db1)
+        self.sync(db3, self.db1)
+        self.assertTrue(self.db2.get_doc('the-doc').has_conflicts)
+        self.assertTrue(db3.get_doc('the-doc').has_conflicts)
+        # resolve
+        conflicts = self.db2.get_doc_conflicts('the-doc')
+        doc4 = self.make_document('the-doc', None, '{"a": 4}')
+        revs = [doc.rev for doc in conflicts]
+        self.db2.resolve_doc(doc4, revs)
+        doc2 = self.db2.get_doc('the-doc')
+        self.assertEqual(doc4.get_json(), doc2.get_json())
+        self.assertFalse(doc2.has_conflicts)
+        self.sync(self.db2, db3)
+        doc3 = db3.get_doc('the-doc')
+        if '_encryption_scheme' in doc3.content:
+            doc3.set_json(
+                decrypt_doc_json(
+                    self._soledad._crypto, doc3.doc_id, doc3.get_json()))
+        self.assertEqual(doc4.get_json(), doc3.get_json())
+        self.assertFalse(doc3.has_conflicts)
+
+    def test_sync_puts_changes(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        doc = self.db1.create_doc_from_json(tests.simple_doc)
+        self.assertEqual(1, self.sync(self.db1, self.db2))
+        exp_doc = self.make_document(
+            doc.doc_id, doc.rev, tests.simple_doc, False)
+        doc2 = self.db2.get_doc(doc.doc_id)
+         # decrypt to compare it it is the case
+        if '_encryption_scheme' in doc2.content:
+            doc2 = self.db2.get_doc(doc.doc_id)
+            doc2.set_json(
+                decrypt_doc_json(
+                    self._soledad._crypto, doc.doc_id, doc2.get_json()))
+        self.assertEqual(exp_doc, doc2)
+        self.assertEqual(1, self.db1._get_replica_gen_and_trans_id('test2')[0])
+        self.assertEqual(1, self.db2._get_replica_gen_and_trans_id('test1')[0])
+        self.assertLastExchangeLog(
+            self.db2,
+            {'receive': {'docs': [(doc.doc_id, doc.rev)],
+                         'source_uid': 'test1',
+                         'source_gen': 1, 'last_known_gen': 0},
+             'return': {'docs': [], 'last_gen': 1}})
+
 
 def _make_local_db_and_leap_target(test, path='test'):
     test.startServer()
     db = test.request_state._create_database(os.path.basename(path))
-    st = LeapSyncTarget.connect(test.getURL(path))
+    st = LeapSyncTarget.connect(test.getURL(path), test._soledad._crypto)
     return db, st
 
 
@@ -464,11 +625,114 @@ target_scenarios = [
 ]
 
 
-class SQLCipherSyncTargetTests(test_sync.DatabaseSyncTargetTests):
+class SQLCipherSyncTargetTests(
+        test_sync.DatabaseSyncTargetTests, BaseSoledadTest):
 
     scenarios = (tests.multiply_scenarios(SQLCIPHER_SCENARIOS,
                                           target_scenarios))
 
+    def setUp(self):
+        test_sync.DatabaseSyncTargetTests.setUp(self)
+        BaseSoledadTest.setUp(self)
+
+    def tearDown(self):
+        test_sync.DatabaseSyncTargetTests.tearDown(self)
+        BaseSoledadTest.tearDown(self)
+
+    def test_sync_exchange(self):
+        """
+        Modified to account for possibly receiving encrypted documents from
+        sever-side.
+        """
+        docs_by_gen = [
+            (self.make_document('doc-id', 'replica:1', tests.simple_doc), 10,
+             'T-sid')]
+        new_gen, trans_id = self.st.sync_exchange(
+            docs_by_gen, 'replica', last_known_generation=0,
+            last_known_trans_id=None, return_doc_cb=self.receive_doc)
+        # decrypt doc1 for comparison if needed
+        tmpdoc = self.db.get_doc('doc-id')
+        if '_encryption_scheme' in tmpdoc.content:
+            tmpdoc.set_json(
+                decrypt_doc_json(
+                    self._soledad._crypto, tmpdoc.doc_id,
+                    tmpdoc.get_json()))
+        self.assertEqual(tmpdoc.rev, 'replica:1')
+        self.assertEqual(tmpdoc.content, json.loads(tests.simple_doc))
+        self.assertFalse(tmpdoc.has_conflicts)
+        self.assertTransactionLog(['doc-id'], self.db)
+        last_trans_id = self.getLastTransId(self.db)
+        self.assertEqual(([], 1, last_trans_id),
+                         (self.other_changes, new_gen, last_trans_id))
+        self.assertEqual(10, self.st.get_sync_info('replica')[3])
+
+    def test_sync_exchange_push_many(self):
+        """
+        Modified to account for possibly receiving encrypted documents from
+        sever-side.
+        """
+        docs_by_gen = [
+            (self.make_document('doc-id', 'replica:1', tests.simple_doc), 10,
+             'T-1'),
+            (self.make_document('doc-id2', 'replica:1', tests.nested_doc), 11,
+             'T-2')]
+        new_gen, trans_id = self.st.sync_exchange(
+            docs_by_gen, 'replica', last_known_generation=0,
+            last_known_trans_id=None, return_doc_cb=self.receive_doc)
+        # decrypt doc1 for comparison if needed
+        tmpdoc1 = self.db.get_doc('doc-id')
+        if '_encryption_scheme' in tmpdoc1.content:
+            tmpdoc1.set_json(
+                decrypt_doc_json(
+                    self._soledad._crypto, tmpdoc1.doc_id,
+                    tmpdoc1.get_json()))
+        self.assertEqual(tmpdoc1.rev, 'replica:1')
+        self.assertEqual(tmpdoc1.content, json.loads(tests.simple_doc))
+        self.assertFalse(tmpdoc1.has_conflicts)
+        # decrypt doc2 for comparison if needed
+        tmpdoc2 = self.db.get_doc('doc-id2')
+        if '_encryption_scheme' in tmpdoc2.content:
+            tmpdoc2.set_json(
+                decrypt_doc_json(
+                    self._soledad._crypto, tmpdoc2.doc_id,
+                    tmpdoc2.get_json()))
+        self.assertEqual(tmpdoc2.rev, 'replica:1')
+        self.assertEqual(tmpdoc2.content, json.loads(tests.nested_doc))
+        self.assertFalse(tmpdoc2.has_conflicts)
+        self.assertTransactionLog(['doc-id', 'doc-id2'], self.db)
+        last_trans_id = self.getLastTransId(self.db)
+        self.assertEqual(([], 2, last_trans_id),
+                         (self.other_changes, new_gen, trans_id))
+        self.assertEqual(11, self.st.get_sync_info('replica')[3])
+
+    def test_sync_exchange_returns_many_new_docs(self):
+        """
+        Modified to account for JSON serialization differences.
+        """
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        doc2 = self.db.create_doc_from_json(tests.nested_doc)
+        self.assertTransactionLog([doc.doc_id, doc2.doc_id], self.db)
+        new_gen, _ = self.st.sync_exchange(
+            [], 'other-replica', last_known_generation=0,
+            last_known_trans_id=None, return_doc_cb=self.receive_doc)
+        self.assertTransactionLog([doc.doc_id, doc2.doc_id], self.db)
+        self.assertEqual(2, new_gen)
+        self.assertEqual(
+            [(doc.doc_id, doc.rev, 1),
+             (doc2.doc_id, doc2.rev, 2)],
+            [c[:2]+c[3:4] for c in self.other_changes])
+        self.assertEqual(
+            json.dumps(tests.simple_doc),
+            json.dumps(self.other_changes[0][2]))
+        self.assertEqual(
+            json.loads(tests.nested_doc),
+            json.loads(self.other_changes[1][2]))
+        if self.whitebox:
+            self.assertEqual(
+                self.db._last_exchange_log['return'],
+                {'last_gen': 2, 'docs':
+                 [(doc.doc_id, doc.rev), (doc2.doc_id, doc2.rev)]})
+
 
 #-----------------------------------------------------------------------------
 # Tests for actual encryption of the database