encryptors: Unbind LuksEncryptor and CryptsetupEncryptor

We want to remove the deprecated 'CryptsetupEncryptor' encryptor, but
'LuksEncryptor' and the 'Luks2Encryptor' subclass depend on it. Fix this
by copying across the common code, allowing us to remove
'CryptsetupEncryptor' in a future change.

Change-Id: I7c523dc982803b337a51c111b01e170bba7c341f
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>

os_brick/encryptors/luks.py

@@ -13,10 +13,14 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from oslo_concurrency import processutils as putils
+import binascii
+import os
+
+from oslo_concurrency import processutils
 from oslo_log import log as logging
 
-from os_brick.encryptors import cryptsetup
+from os_brick.encryptors import base
+from os_brick import exception
 from os_brick.privileged import rootwrap as priv_rootwrap
 from os_brick import utils
 
@@ -38,14 +42,14 @@ def is_luks(root_helper, device, execute=None):
                 run_as_root=True, root_helper=root_helper,
                 check_exit_code=True)
         return True
-    except putils.ProcessExecutionError as e:
+    except processutils.ProcessExecutionError as e:
         LOG.warning("isLuks exited abnormally (status %(exit_code)s): "
                     "%(stderr)s",
                     {"exit_code": e.exit_code, "stderr": e.stderr})
         return False
 
 
-class LuksEncryptor(cryptsetup.CryptsetupEncryptor):
+class LuksEncryptor(base.VolumeEncryptor):
     """A VolumeEncryptor based on LUKS.
 
     This VolumeEncryptor uses dm-crypt to encrypt the specified volume.
@@ -62,6 +66,59 @@ class LuksEncryptor(cryptsetup.CryptsetupEncryptor):
             execute=execute,
             *args, **kwargs)
 
+        # Fail if no device_path was set when connecting the volume, e.g. in
+        # the case of libvirt network volume drivers.
+        data = connection_info['data']
+        if not data.get('device_path'):
+            volume_id = data.get('volume_id') or connection_info.get('serial')
+            raise exception.VolumeEncryptionNotSupported(
+                volume_id=volume_id,
+                volume_type=connection_info['driver_volume_type'])
+
+        # the device's path as given to libvirt -- e.g., /dev/disk/by-path/...
+        self.symlink_path = connection_info['data']['device_path']
+
+        # a unique name for the volume -- e.g., the iSCSI participant name
+        self.dev_name = 'crypt-%s' % os.path.basename(self.symlink_path)
+
+        # NOTE(lixiaoy1): This is to import fix for 1439869 from Nova.
+        # NOTE(tsekiyama): In older version of nova, dev_name was the same
+        # as the symlink name. Now it has 'crypt-' prefix to avoid conflict
+        # with multipath device symlink. To enable rolling update, we use the
+        # old name when the encrypted volume already exists.
+        old_dev_name = os.path.basename(self.symlink_path)
+        wwn = data.get('multipath_id')
+        if self._is_crypt_device_available(old_dev_name):
+            self.dev_name = old_dev_name
+            LOG.debug("Using old encrypted volume name: %s", self.dev_name)
+        elif wwn and wwn != old_dev_name:
+            # FibreChannel device could be named '/dev/mapper/<WWN>'.
+            if self._is_crypt_device_available(wwn):
+                self.dev_name = wwn
+                LOG.debug(
+                    "Using encrypted volume name from wwn: %s", self.dev_name)
+
+        # the device's actual path on the compute host -- e.g., /dev/sd_
+        self.dev_path = os.path.realpath(self.symlink_path)
+
+    def _is_crypt_device_available(self, dev_name):
+        if not os.path.exists('/dev/mapper/%s' % dev_name):
+            return False
+
+        try:
+            self._execute('cryptsetup', 'status', dev_name, run_as_root=True)
+        except processutils.ProcessExecutionError as e:
+            # If /dev/mapper/<dev_name> is a non-crypt block device (such as a
+            # normal disk or multipath device), exit_code will be 1. In the
+            # case, we will omit the warning message.
+            if e.exit_code != 1:
+                LOG.warning('cryptsetup status %(dev_name)s exited '
+                            'abnormally (status %(exit_code)s): %(err)s',
+                            {"dev_name": dev_name, "exit_code": e.exit_code,
+                             "err": e.stderr})
+            return False
+        return True
+
     def _format_volume(self, passphrase, **kwargs):
         """Creates a LUKS v1 header on the volume.
 
@@ -103,6 +160,10 @@ class LuksEncryptor(cryptsetup.CryptsetupEncryptor):
                       root_helper=self._root_helper,
                       attempts=3)
 
+    def _get_passphrase(self, key):
+        """Convert raw key to string."""
+        return binascii.hexlify(key).decode('utf-8')
+
     def _open_volume(self, passphrase, **kwargs):
         """Opens the LUKS partition on the volume using passphrase.
 
@@ -128,7 +189,7 @@ class LuksEncryptor(cryptsetup.CryptsetupEncryptor):
 
         try:
             self._open_volume(passphrase, **kwargs)
-        except putils.ProcessExecutionError as e:
+        except processutils.ProcessExecutionError as e:
             if e.exit_code == 1 and not is_luks(self._root_helper,
                                                 self.dev_path,
                                                 execute=self._execute):
@@ -160,6 +221,10 @@ class LuksEncryptor(cryptsetup.CryptsetupEncryptor):
                       root_helper=self._root_helper,
                       attempts=3)
 
+    def detach_volume(self, **kwargs):
+        """Removes the dm-crypt mapping for the device."""
+        self._close_volume(**kwargs)
+
     def extend_volume(self, context, **kwargs):
         """Extend an encrypted volume and return the decrypted volume size."""
         symlink = self.symlink_path

os_brick/tests/encryptors/test_luks.py

@@ -13,16 +13,35 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import binascii
+import copy
 from unittest import mock
 
+from castellan.common.objects import symmetric_key as key
+from castellan.tests.unit.key_manager import fake
 from oslo_concurrency import processutils as putils
 
-from os_brick.encryptors import cryptsetup
 from os_brick.encryptors import luks
-from os_brick.tests.encryptors import test_cryptsetup
+from os_brick import exception
+from os_brick.tests.encryptors import test_base
 
 
-class LuksEncryptorTestCase(test_cryptsetup.CryptsetupEncryptorTestCase):
+def fake__get_key(context, passphrase):
+    raw = bytes(binascii.unhexlify(passphrase))
+    symmetric_key = key.SymmetricKey('AES', len(raw) * 8, raw)
+    return symmetric_key
+
+
+class LuksEncryptorTestCase(test_base.VolumeEncryptorTestCase):
+
+    def setUp(self):
+        super().setUp()
+
+        self.dev_path = self.connection_info['data']['device_path']
+        self.dev_name = 'crypt-%s' % self.dev_path.split('/')[-1]
+
+        self.symlink_path = self.dev_path
+
     def _create(self):
         return luks.LuksEncryptor(root_helper=self.root_helper,
                                   connection_info=self.connection_info,
@@ -82,8 +101,7 @@ class LuksEncryptorTestCase(test_cryptsetup.CryptsetupEncryptorTestCase):
     def test_attach_volume(self, mock_execute):
         fake_key = '0c84146034e747639b698368807286df'
         self.encryptor._get_key = mock.MagicMock()
-        self.encryptor._get_key.return_value = (
-            test_cryptsetup.fake__get_key(None, fake_key))
+        self.encryptor._get_key.return_value = fake__get_key(None, fake_key)
 
         self.encryptor.attach_volume(None)
 
@@ -102,8 +120,7 @@ class LuksEncryptorTestCase(test_cryptsetup.CryptsetupEncryptorTestCase):
     def test_attach_volume_not_formatted(self, mock_execute):
         fake_key = 'bc37c5eccebe403f9cc2d0dd20dac2bc'
         self.encryptor._get_key = mock.MagicMock()
-        self.encryptor._get_key.return_value = (
-            test_cryptsetup.fake__get_key(None, fake_key))
+        self.encryptor._get_key.return_value = fake__get_key(None, fake_key)
 
         mock_execute.side_effect = [
             putils.ProcessExecutionError(exit_code=1),  # luksOpen
@@ -142,8 +159,7 @@ class LuksEncryptorTestCase(test_cryptsetup.CryptsetupEncryptorTestCase):
     def test_attach_volume_fail(self, mock_execute):
         fake_key = 'ea6c2e1b8f7f4f84ae3560116d659ba2'
         self.encryptor._get_key = mock.MagicMock()
-        self.encryptor._get_key.return_value = (
-            test_cryptsetup.fake__get_key(None, fake_key))
+        self.encryptor._get_key.return_value = fake__get_key(None, fake_key)
 
         mock_execute.side_effect = [
             putils.ProcessExecutionError(exit_code=1),  # luksOpen
@@ -183,10 +199,63 @@ class LuksEncryptorTestCase(test_cryptsetup.CryptsetupEncryptorTestCase):
                       attempts=3, run_as_root=True, check_exit_code=[0, 4]),
         ])
 
+    def test_init_volume_encryption_not_supported(self):
+        # Tests that creating a CryptsetupEncryptor fails if there is no
+        # device_path key.
+        type = 'unencryptable'
+        data = dict(volume_id='a194699b-aa07-4433-a945-a5d23802043e')
+        connection_info = dict(driver_volume_type=type, data=data)
+        exc = self.assertRaises(exception.VolumeEncryptionNotSupported,
+                                luks.LuksEncryptor,
+                                root_helper=self.root_helper,
+                                connection_info=connection_info,
+                                keymgr=fake.fake_api())
+        self.assertIn(type, str(exc))
+
+    @mock.patch('os_brick.executor.Executor._execute')
+    @mock.patch('os.path.exists', return_value=True)
+    def test_init_volume_encryption_with_old_name(self, mock_exists,
+                                                  mock_execute):
+        # If an old name crypt device exists, dev_path should be the old name.
+        old_dev_name = self.dev_path.split('/')[-1]
+        encryptor = luks.LuksEncryptor(
+            root_helper=self.root_helper,
+            connection_info=self.connection_info,
+            keymgr=self.keymgr)
+        self.assertFalse(encryptor.dev_name.startswith('crypt-'))
+        self.assertEqual(old_dev_name, encryptor.dev_name)
+        self.assertEqual(self.dev_path, encryptor.dev_path)
+        self.assertEqual(self.symlink_path, encryptor.symlink_path)
+        mock_exists.assert_called_once_with('/dev/mapper/%s' % old_dev_name)
+        mock_execute.assert_called_once_with(
+            'cryptsetup', 'status', old_dev_name, run_as_root=True)
+
+    @mock.patch('os_brick.executor.Executor._execute')
+    @mock.patch('os.path.exists', side_effect=[False, True])
+    def test_init_volume_encryption_with_wwn(self, mock_exists, mock_execute):
+        # If an wwn name crypt device exists, dev_path should be based on wwn.
+        old_dev_name = self.dev_path.split('/')[-1]
+        wwn = 'fake_wwn'
+        connection_info = copy.deepcopy(self.connection_info)
+        connection_info['data']['multipath_id'] = wwn
+        encryptor = luks.LuksEncryptor(
+            root_helper=self.root_helper,
+            connection_info=connection_info,
+            keymgr=fake.fake_api())
+        self.assertFalse(encryptor.dev_name.startswith('crypt-'))
+        self.assertEqual(wwn, encryptor.dev_name)
+        self.assertEqual(self.dev_path, encryptor.dev_path)
+        self.assertEqual(self.symlink_path, encryptor.symlink_path)
+        mock_exists.assert_has_calls([
+            mock.call('/dev/mapper/%s' % old_dev_name),
+            mock.call('/dev/mapper/%s' % wwn)])
+        mock_execute.assert_called_once_with(
+            'cryptsetup', 'status', wwn, run_as_root=True)
+
     @mock.patch('os_brick.utils.get_device_size')
-    @mock.patch.object(cryptsetup.CryptsetupEncryptor, '_execute')
-    @mock.patch.object(cryptsetup.CryptsetupEncryptor, '_get_passphrase')
-    @mock.patch.object(cryptsetup.CryptsetupEncryptor, '_get_key')
+    @mock.patch.object(luks.LuksEncryptor, '_execute')
+    @mock.patch.object(luks.LuksEncryptor, '_get_passphrase')
+    @mock.patch.object(luks.LuksEncryptor, '_get_key')
     def test_extend_volume(self, mock_key, mock_pass, mock_exec, mock_size):
         encryptor = self.encryptor
         res = encryptor.extend_volume(mock.sentinel.context)
@@ -225,8 +294,7 @@ class Luks2EncryptorTestCase(LuksEncryptorTestCase):
     def test_attach_volume_not_formatted(self, mock_execute):
         fake_key = 'bc37c5eccebe403f9cc2d0dd20dac2bc'
         self.encryptor._get_key = mock.MagicMock()
-        self.encryptor._get_key.return_value = (
-            test_cryptsetup.fake__get_key(None, fake_key))
+        self.encryptor._get_key.return_value = fake__get_key(None, fake_key)
 
         mock_execute.side_effect = [
             putils.ProcessExecutionError(exit_code=1),  # luksOpen