[feat] use OpenSSL backend for scrypt if available

This needs OpenSSL >= 1.1, otherwise it will keep using the scrypt
dependency.

We should think about deprecating scrypt as a dependency when we can be
sure that the adoption of libssl 1.1 is wide enough. I think that at
some point (soledad 0.11 or so) we can drop the scrypt dependency, which
was being somehow problematic at times (the _scrypt.so was not appearing
when installing with pip, needed workarounds). From that moment on, we
can raise an error if an old libssl is found and no scrypt can be
imported - leaving that to the user/packager.

In debian stretch and afterwards, you can get that version by installing
libssl-dev

- Related: #8472

10 files changed, 81 insertions, 38 deletions

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 5c1171d5..7df072f9 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,3 +1,24 @@
+Changelog
+=========
+
+0.10.0 - `master`_
++++++++++++++++++++++++++++++++
+
+.. note:: This version is not yet released and is under active development.
+
+Client
+~~~~~~
+
+- `#8472 <https://0xacab.org/leap/soledad/issues/8472>`_: Use OpenSSL backend for scrypt if OpenSSL >= 1.1
+
+Misc
+~~~~
+
+- Unification of Client, Server and Common in a Single python package.
+
+
+
+
 0.9.6 - 31 May, 2017
 +++++++++++++++++++++++++++++++
 
@@ -235,3 +256,6 @@ Features
 Bugfixes
 ~~~~~~~~
 - `#7626 <https://leap.se/code/issues/7626>`_: Subclass a leaky leap.common.couch exception to avoid depending on couch.
+
+
+.. _`master`: https://0xacab.org/leap/soledad
diff --git a/docs/changelog-next.rst b/docs/changelog-next.rst
deleted file mode 100644
index f7a90692..00000000
--- a/docs/changelog-next.rst
+++ /dev/null
@@ -1,27 +0,0 @@
-0.9.7 - 
-+++++++++++++++++++++++++++++++
-
-Please add lines to this file, they will be moved to the CHANGELOG.rst during
-the next release.
-
-There are two template lines for each category, use them as reference.
-
-I've added a new category `Misc` so we can track doc/style/packaging stuff.
-
-Features
-~~~~~~~~
-- `#1234 <https://leap.se/code/issues/1234>`_: Description of the new feature corresponding with issue #1234.
-- New feature without related issue number.
-
-Bugfixes
-~~~~~~~~
-- `#1235 <https://leap.se/code/issues/1235>`_: Description for the fixed stuff corresponding with issue #1235.
-- Bugfix without related issue number.
-
-Other
-~~~~~
-- `#1236 <https://leap.se/code/issues/1236>`_: Description of the new feature corresponding with issue #1236.
-- Some change without issue number.
-
-Known Issues
-~~~~~~~~~~~~
diff --git a/docs/changelog.rst b/docs/changelog.rst
new file mode 100644
index 00000000..565b0521
--- /dev/null
+++ b/docs/changelog.rst
@@ -0,0 +1 @@
+.. include:: ../CHANGELOG.rst
diff --git a/docs/index.rst b/docs/index.rst
index 0ebe1a7f..42a82a7a 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -20,6 +20,7 @@ all user's devices that access a LEAP provider.
    incoming_box
    deprecation
    benchmarks
+   changelog
 
 Indices and tables
 ==================
diff --git a/src/leap/soledad/client/_scrypt.py b/src/leap/soledad/client/_scrypt.py
new file mode 100644
index 00000000..2de3ab5e
--- /dev/null
+++ b/src/leap/soledad/client/_scrypt.py
@@ -0,0 +1,33 @@
+# -*- coding: utf-8 -*-
+# _scrypt.py
+# Copyright (C) 2017 LEAP Encryption Access Project
+#
+# 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/>.
+
+from cryptography.hazmat.backends.interfaces import ScryptBackend
+from cryptography.hazmat.backends import default_backend
+
+backend = default_backend()
+OPENSSL_HAS_SCRYPT = isinstance(backend, ScryptBackend)
+
+if OPENSSL_HAS_SCRYPT:
+    from cryptography.hazmat.primitives.kdf.scrypt import Scrypt
+
+    def hash(secret, salt, buflen=32):
+        return Scrypt(salt, buflen, 16384, 8, 1, backend).derive(secret)
+else:
+    import scrypt
+
+    def hash(secret, salt, buflen=32):
+        return scrypt.hash(secret, salt, buflen=buflen)
diff --git a/src/leap/soledad/client/_secrets/__init__.py b/src/leap/soledad/client/_secrets/__init__.py
index b6c81cda..c92b9905 100644
--- a/src/leap/soledad/client/_secrets/__init__.py
+++ b/src/leap/soledad/client/_secrets/__init__.py
@@ -16,13 +16,13 @@
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 import os
-import scrypt
 
 from leap.soledad.common.log import getLogger
 
 from leap.soledad.client._secrets.storage import SecretsStorage
 from leap.soledad.client._secrets.crypto import SecretsCrypto
 from leap.soledad.client._secrets.util import emit, UserDataMixin
+from leap.soledad.client import _scrypt
 
 
 logger = getLogger(__name__)
@@ -121,9 +121,8 @@ class Secrets(UserDataMixin):
     def local_key(self):
         # local storage key is scrypt-derived from `local_secret` and
         # `local_salt` above
-        secret = scrypt.hash(
-            password=self.local_secret,
+        return _scrypt.hash(
+            self.local_secret,
             salt=self.local_salt,
             buflen=32,  # we need a key with 256 bits (32 bytes)
         )
-        return secret
diff --git a/src/leap/soledad/client/_secrets/crypto.py b/src/leap/soledad/client/_secrets/crypto.py
index 8148151d..975b790b 100644
--- a/src/leap/soledad/client/_secrets/crypto.py
+++ b/src/leap/soledad/client/_secrets/crypto.py
@@ -18,13 +18,13 @@
 import binascii
 import json
 import os
-import scrypt
 
 from leap.soledad.common import soledad_assert
 from leap.soledad.common.log import getLogger
 
 from leap.soledad.client._crypto import encrypt_sym, decrypt_sym, ENC_METHOD
 from leap.soledad.client._secrets.util import SecretsError
+from leap.soledad.client import _scrypt
 
 
 logger = getLogger(__name__)
@@ -39,7 +39,7 @@ class SecretsCrypto(object):
 
     def _get_key(self, salt):
         passphrase = self._soledad.passphrase.encode('utf8')
-        key = scrypt.hash(passphrase, salt, buflen=32)
+        key = _scrypt.hash(passphrase, salt, buflen=32)
         return key
 
     #
diff --git a/testing/requirements-testing.pip b/testing/requirements-testing.pip
index a33c65ab..a80b1b34 100644
--- a/testing/requirements-testing.pip
+++ b/testing/requirements-testing.pip
@@ -1,2 +1,3 @@
 pip
-tox
\ No newline at end of file
+tox
+pytest-twisted
diff --git a/testing/tests/client/test_crypto.py b/testing/tests/client/test_crypto.py
index 11384ad7..10cccbb2 100644
--- a/testing/tests/client/test_crypto.py
+++ b/testing/tests/client/test_crypto.py
@@ -33,6 +33,7 @@ from cryptography.exceptions import InvalidTag
 from leap.soledad.common.document import SoledadDocument
 from test_soledad.util import BaseSoledadTest
 from leap.soledad.client import _crypto
+from leap.soledad.client import _scrypt
 
 from twisted.trial import unittest
 from twisted.internet import defer
@@ -46,6 +47,17 @@ snowden1 = (
     "they will.")
 
 
+class ScryptTest(unittest.TestCase):
+
+    def test_scrypt(self):
+        secret = 'supersikret'
+        salt = 'randomsalt'
+        key = _scrypt.hash(secret, salt, buflen=32)
+        expected = ('47996b569ea58d51ccbcc318d710'
+                    'a537acd28bb7a94615ab8d061d4b2a920f01')
+        assert binascii.b2a_hex(key) == expected
+
+
 class AESTest(unittest.TestCase):
 
     def test_chunked_encryption(self):
diff --git a/testing/tox.ini b/testing/tox.ini
index bb8f0913..6a6275f3 100644
--- a/testing/tox.ini
+++ b/testing/tox.ini
@@ -5,8 +5,7 @@ skipsdist=True
 [testenv]
 basepython = python2.7
 commands = 
-    pip uninstall -y pysqlcipher
-    pip install --install-option="--bundled" pysqlcipher
+    pip install -I --install-option="--bundled" pysqlcipher
     py.test -x --ignore=tests/benchmarks \
                    --cov-report=html \
                    --cov-report=term \
@@ -25,6 +24,7 @@ deps =
     couchdb
     requests
     service_identity
+    leap.common
 # install soledad from current tree
     -e../
     -e../[client]
@@ -75,8 +75,7 @@ deps =
 commands =
 # use a bundled version of pysqlcipher to ensure HAVE_USLEEP is set and we
 # don't have problems with concurrent db access.
-    pip uninstall -y pysqlcipher
-    pip install --install-option="--bundled" pysqlcipher
+    pip install -I --install-option="--bundled" pysqlcipher
     ./check-pysqlcipher.py
 # and only then run benchmark
     py.test --benchmark-only -m 'not synchronous' {posargs}