XEP-0373, XEP-0374: OpenPGP for XMPP: Instant Messaging

build.gradle

@@ -79,6 +79,7 @@ allprojects {
 			':smack-experimental',
 			':smack-omemo',
 			':smack-omemo-signal',
+			':smack-openpgp',
 		].collect{ project(it) }
 		androidBootClasspathProjects = [
 			':smack-android',

documentation/extensions/index.md

@@ -96,6 +96,8 @@ Experimental Smack Extensions and currently supported XEPs of smack-experimental
 | Stable and Unique Stanza IDs                              | [XEP-0359](https://xmpp.org/extensions/xep-0359.html)  | 0.5.0     | This specification describes unique and stable IDs for messages. |
 | HTTP File Upload                                          | [XEP-0363](https://xmpp.org/extensions/xep-0363.html)  | 0.3.1     | Protocol to request permissions to upload a file to an HTTP server and get a shareable URL. |
 | References                                                | [XEP-0372](https://xmpp.org/extensions/xep-0363.html)  | 0.2.0     | Add references like mentions or external data to stanzas. |
+| [OpenPGP for XMPP](ox.md)                                 | [XEP-0373](https://xmpp.org/extensions/xep-0373.html)  | 0.3.2     | Utilize OpenPGP to exchange encrypted and signed content. |
+| [OpenPGP for XMPP: Instant Messaging](ox-im.md)           | [XEP-0374](https://xmpp.org/extensions/xep-0374.html)  | 0.2.0     | OpenPGP encrypted Instant Messaging. |
 | [Spoiler Messages](spoiler.md)                            | [XEP-0382](https://xmpp.org/extensions/xep-0382.html)  | 0.2.0     | Indicate that the body of a message should be treated as a spoiler. |
 | [OMEMO Multi End Message and Object Encryption](omemo.md) | [XEP-0384](https://xmpp.org/extensions/xep-0384.html)  | n/a       | Encrypt messages using OMEMO encryption (currently only with smack-omemo-signal -> GPLv3). |
 | [Consistent Color Generation](consistent_colors.md)       | [XEP-0392](https://xmpp.org/extensions/xep-0392.html)  | 0.4.0     | Generate consistent colors for identifiers like usernames to provide a consistent user experience. |

documentation/extensions/ox-im.md

@@ -0,0 +1,6 @@
+OpenPGP for XMPP: Instant Messaging
+===================================
+
+[Back](index.md)
+
+See the javadoc of `OpenPgpManager` and `OXInstantMessagingManager` for details.

documentation/extensions/ox.md

@@ -0,0 +1,6 @@
+OpenPGP for XMPP
+================
+
+[Back](index.md)
+
+See the javadoc of `OpenPgpManager` for details.

settings.gradle

@@ -26,4 +26,5 @@ include 'smack-core',
 		'smack-omemo',
 		'smack-omemo-signal',
 		'smack-omemo-signal-integration-test',
-		'smack-repl'
+		'smack-repl',
+		'smack-openpgp'

smack-core/src/main/java/org/jivesoftware/smack/util/FileUtils.java

@@ -158,6 +158,9 @@ public static boolean writeFile(File file, CharSequence content) {
     }
 
     public static void deleteDirectory(File root) {
+        if (!root.exists()) {
+            return;
+        }
         File[] currList;
         Stack<File> stack = new Stack<>();
         stack.push(root);
@@ -176,4 +179,25 @@ public static void deleteDirectory(File root) {
             }
         }
     }
+
+    /**
+     * Returns a {@link File} pointing to a temporary directory. On unix like systems this might be {@code /tmp}
+     * for example.
+     * If {@code suffix} is not null, the returned file points to {@code <temp>/suffix}.
+     *
+     * @param suffix optional path suffix
+     * @return temp directory
+     */
+    public static File getTempDir(String suffix) {
+        String temp = System.getProperty("java.io.tmpdir");
+        if (temp == null) {
+            temp = "tmp";
+        }
+
+        if (suffix == null) {
+            return new File(temp);
+        } else {
+            return new File(temp, suffix);
+        }
+    }
 }

smack-core/src/main/resources/org.jivesoftware.smack/smack-config.xml

@@ -21,5 +21,6 @@
         <className>org.jivesoftware.smack.java7.Java7SmackInitializer</className>
         <className>org.jivesoftware.smack.im.SmackImInitializer</className>
         <className>org.jivesoftware.smackx.omemo.OmemoInitializer</className>
+        <className>org.jivesoftware.smackx.ox.util.OpenPgpInitializer</className>
     </optionalStartupClasses>
 </smack>

smack-integration-test/build.gradle

@@ -12,6 +12,7 @@ dependencies {
 	compile project(':smack-extensions')
 	compile project(':smack-experimental')
 	compile project(':smack-omemo')
+	compile project(':smack-openpgp')
 	compile project(':smack-debug')
 	compile project(path: ":smack-omemo", configuration: "testRuntime")
 	compile 'org.reflections:reflections:0.9.9-RC1'

smack-integration-test/src/main/java/org/jivesoftware/smackx/ox/AbstractOpenPgpIntegrationTest.java

@@ -0,0 +1,70 @@
+/**
+ *
+ * Copyright 2018 Paul Schaub.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.ox;
+
+import org.jivesoftware.smack.SmackException;
+import org.jivesoftware.smack.XMPPConnection;
+import org.jivesoftware.smack.XMPPException;
+import org.jivesoftware.smackx.ox.util.OpenPgpPubSubUtil;
+import org.jivesoftware.smackx.pep.PEPManager;
+
+import org.igniterealtime.smack.inttest.AbstractSmackIntegrationTest;
+import org.igniterealtime.smack.inttest.SmackIntegrationTestEnvironment;
+import org.igniterealtime.smack.inttest.TestNotPossibleException;
+import org.jxmpp.jid.BareJid;
+
+public abstract class AbstractOpenPgpIntegrationTest extends AbstractSmackIntegrationTest {
+
+    protected final XMPPConnection aliceConnection;
+    protected final XMPPConnection bobConnection;
+    protected final XMPPConnection chloeConnection;
+
+    protected final BareJid alice;
+    protected final BareJid bob;
+    protected final BareJid chloe;
+
+    protected AbstractOpenPgpIntegrationTest(SmackIntegrationTestEnvironment environment)
+            throws XMPPException.XMPPErrorException, TestNotPossibleException, SmackException.NotConnectedException,
+            InterruptedException, SmackException.NoResponseException {
+        super(environment);
+
+        throwIfPubSubNotSupported(conOne);
+        throwIfPubSubNotSupported(conTwo);
+        throwIfPubSubNotSupported(conThree);
+
+        this.aliceConnection = conOne;
+        this.bobConnection = conTwo;
+        this.chloeConnection = conThree;
+
+        this.alice = aliceConnection.getUser().asBareJid();
+        this.bob = bobConnection.getUser().asBareJid();
+        this.chloe = chloeConnection.getUser().asBareJid();
+
+        OpenPgpPubSubUtil.deletePubkeysListNode(aliceConnection);
+        OpenPgpPubSubUtil.deletePubkeysListNode(bobConnection);
+        OpenPgpPubSubUtil.deletePubkeysListNode(chloeConnection);
+    }
+
+    private static void throwIfPubSubNotSupported(XMPPConnection connection)
+            throws XMPPException.XMPPErrorException, SmackException.NotConnectedException, InterruptedException,
+            SmackException.NoResponseException, TestNotPossibleException {
+        if (!PEPManager.getInstanceFor(connection).isSupported()) {
+            throw new TestNotPossibleException("Server " + connection.getXMPPServiceDomain().toString() +
+                    " does not support PEP.");
+        }
+    }
+}

smack-integration-test/src/main/java/org/jivesoftware/smackx/ox/OXSecretKeyBackupIntegrationTest.java

@@ -0,0 +1,196 @@
+/**
+ *
+ * Copyright 2018 Paul Schaub.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.ox;
+
+import static junit.framework.TestCase.assertEquals;
+import static junit.framework.TestCase.assertNotNull;
+import static junit.framework.TestCase.assertNull;
+import static junit.framework.TestCase.assertTrue;
+
+import java.io.File;
+import java.io.IOException;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.util.Arrays;
+import java.util.Set;
+import java.util.logging.Level;
+
+import org.jivesoftware.smack.SmackException;
+import org.jivesoftware.smack.XMPPException;
+import org.jivesoftware.smack.util.FileUtils;
+import org.jivesoftware.smack.util.StringUtils;
+import org.jivesoftware.smackx.ox.callback.backup.AskForBackupCodeCallback;
+import org.jivesoftware.smackx.ox.callback.backup.DisplayBackupCodeCallback;
+import org.jivesoftware.smackx.ox.callback.backup.SecretKeyBackupSelectionCallback;
+import org.jivesoftware.smackx.ox.crypto.PainlessOpenPgpProvider;
+import org.jivesoftware.smackx.ox.exception.InvalidBackupCodeException;
+import org.jivesoftware.smackx.ox.exception.MissingOpenPgpKeyException;
+import org.jivesoftware.smackx.ox.exception.MissingUserIdOnKeyException;
+import org.jivesoftware.smackx.ox.exception.NoBackupFoundException;
+import org.jivesoftware.smackx.ox.store.definition.OpenPgpStore;
+import org.jivesoftware.smackx.ox.store.filebased.FileBasedOpenPgpStore;
+import org.jivesoftware.smackx.ox.util.OpenPgpPubSubUtil;
+import org.jivesoftware.smackx.pubsub.PubSubException;
+
+import org.bouncycastle.openpgp.PGPException;
+import org.bouncycastle.openpgp.PGPPublicKeyRing;
+import org.bouncycastle.openpgp.PGPSecretKeyRing;
+import org.igniterealtime.smack.inttest.SmackIntegrationTest;
+import org.igniterealtime.smack.inttest.SmackIntegrationTestEnvironment;
+import org.igniterealtime.smack.inttest.TestNotPossibleException;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.pgpainless.key.OpenPgpV4Fingerprint;
+import org.pgpainless.key.protection.UnprotectedKeysProtector;
+
+public class OXSecretKeyBackupIntegrationTest extends AbstractOpenPgpIntegrationTest {
+
+    private static final String sessionId = StringUtils.randomString(10);
+    private static final File beforePath = FileUtils.getTempDir("ox_backup_" + sessionId);
+    private static final File afterPath = FileUtils.getTempDir("ox_restore_" + sessionId);
+
+    private String backupCode = null;
+
+    private OpenPgpManager openPgpManager;
+
+    /**
+     * This integration test tests the basic secret key backup and restore functionality as described
+     * in XEP-0373 §5.
+     *
+     * In order to simulate two different devices, we are using two {@link FileBasedOpenPgpStore} implementations
+     * which point to different directories.
+     *
+     * First, Alice generates a fresh OpenPGP key pair.
+     *
+     * She then creates a backup of the key in her private PEP node.
+     *
+     * Now the {@link OpenPgpStore} implementation is replaced by another instance to simulate a different device.
+     *
+     * Then the secret key backup is restored from PubSub and the imported secret key is compared to the one in
+     * the original store.
+     *
+     * Afterwards the private PEP node is deleted from PubSub and the storage directories are emptied.
+     *
+     * @see <a href="https://xmpp.org/extensions/xep-0373.html#synchro-pep">
+     *     XEP-0373 §5: Synchronizing the Secret Key with a Private PEP Node</a>
+     * @param environment
+     * @throws XMPPException.XMPPErrorException
+     * @throws TestNotPossibleException
+     * @throws SmackException.NotConnectedException
+     * @throws InterruptedException
+     * @throws SmackException.NoResponseException
+     */
+    public OXSecretKeyBackupIntegrationTest(SmackIntegrationTestEnvironment environment)
+            throws XMPPException.XMPPErrorException, TestNotPossibleException, SmackException.NotConnectedException,
+            InterruptedException, SmackException.NoResponseException {
+        super(environment);
+        if (!OpenPgpManager.serverSupportsSecretKeyBackups(aliceConnection)) {
+            throw new TestNotPossibleException("Server does not support the 'whitelist' PubSub access model.");
+        }
+    }
+
+    @AfterClass
+    @BeforeClass
+    public static void cleanStore() {
+        LOGGER.log(Level.INFO, "Delete store directories...");
+        FileUtils.deleteDirectory(afterPath);
+        FileUtils.deleteDirectory(beforePath);
+    }
+
+    @After
+    @Before
+    public void cleanUp()
+            throws XMPPException.XMPPErrorException, SmackException.NotConnectedException, InterruptedException,
+            SmackException.NoResponseException {
+        OpenPgpPubSubUtil.deleteSecretKeyNode(aliceConnection);
+
+        if (openPgpManager != null) {
+            openPgpManager.stopMetadataListener();
+        }
+    }
+
+    @SmackIntegrationTest
+    public void test() throws InvalidAlgorithmParameterException, NoSuchAlgorithmException,
+            NoSuchProviderException, IOException, InterruptedException, PubSubException.NotALeafNodeException,
+            SmackException.NoResponseException, SmackException.NotConnectedException, XMPPException.XMPPErrorException,
+            SmackException.NotLoggedInException, SmackException.FeatureNotSupportedException,
+            MissingUserIdOnKeyException, NoBackupFoundException, InvalidBackupCodeException, PGPException,
+            MissingOpenPgpKeyException {
+
+        OpenPgpStore beforeStore = new FileBasedOpenPgpStore(beforePath);
+        beforeStore.setKeyRingProtector(new UnprotectedKeysProtector());
+        PainlessOpenPgpProvider beforeProvider = new PainlessOpenPgpProvider(aliceConnection, beforeStore);
+        openPgpManager = OpenPgpManager.getInstanceFor(aliceConnection);
+        openPgpManager.setOpenPgpProvider(beforeProvider);
+
+        OpenPgpSelf self = openPgpManager.getOpenPgpSelf();
+
+        assertNull(self.getSigningKeyFingerprint());
+
+        OpenPgpV4Fingerprint keyFingerprint = openPgpManager.generateAndImportKeyPair(alice);
+        assertEquals(keyFingerprint, self.getSigningKeyFingerprint());
+
+        assertTrue(self.getSecretKeys().contains(keyFingerprint.getKeyId()));
+
+        PGPSecretKeyRing beforeSec = beforeStore.getSecretKeyRing(alice, keyFingerprint);
+        assertNotNull(beforeSec);
+
+        PGPPublicKeyRing beforePub = beforeStore.getPublicKeyRing(alice, keyFingerprint);
+        assertNotNull(beforePub);
+
+        openPgpManager.backupSecretKeyToServer(new DisplayBackupCodeCallback() {
+            @Override
+            public void displayBackupCode(String backupCode) {
+                OXSecretKeyBackupIntegrationTest.this.backupCode = backupCode;
+            }
+        }, new SecretKeyBackupSelectionCallback() {
+            @Override
+            public Set<OpenPgpV4Fingerprint> selectKeysToBackup(Set<OpenPgpV4Fingerprint> availableSecretKeys) {
+                return availableSecretKeys;
+            }
+        });
+
+        FileBasedOpenPgpStore afterStore = new FileBasedOpenPgpStore(afterPath);
+        afterStore.setKeyRingProtector(new UnprotectedKeysProtector());
+        PainlessOpenPgpProvider afterProvider = new PainlessOpenPgpProvider(aliceConnection, afterStore);
+        openPgpManager.setOpenPgpProvider(afterProvider);
+
+        OpenPgpV4Fingerprint fingerprint = openPgpManager.restoreSecretKeyServerBackup(new AskForBackupCodeCallback() {
+            @Override
+            public String askForBackupCode() {
+                return backupCode;
+            }
+        });
+
+        assertEquals(keyFingerprint, fingerprint);
+
+        assertTrue(self.getSecretKeys().contains(keyFingerprint.getKeyId()));
+
+        assertEquals(keyFingerprint, self.getSigningKeyFingerprint());
+
+        PGPSecretKeyRing afterSec = afterStore.getSecretKeyRing(alice, keyFingerprint);
+        assertNotNull(afterSec);
+        assertTrue(Arrays.equals(beforeSec.getEncoded(), afterSec.getEncoded()));
+
+        PGPPublicKeyRing afterPub = afterStore.getPublicKeyRing(alice, keyFingerprint);
+        assertNotNull(afterPub);
+        assertTrue(Arrays.equals(beforePub.getEncoded(), afterPub.getEncoded()));
+    }
+}

smack-integration-test/src/main/java/org/jivesoftware/smackx/ox/package-info.java

@@ -0,0 +1,23 @@
+/**
+ *
+ * Copyright 2018 Paul Schaub
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * Integration Tests for Smacks support for XEP-0373: OpenPGP for XMPP.
+ *
+ * @see <a href="https://xmpp.org/extensions/xep-0373.html">
+ *     XEP-0373: OpenPGP for XMPP</a>
+ */
+package org.jivesoftware.smackx.ox;