1 files changed, 525 insertions, 0 deletions
diff --git a/android/olm-sdk/src/androidTest/java/org/matrix/olm/OlmGroupSessionTest.java b/android/olm-sdk/src/androidTest/java/org/matrix/olm/OlmGroupSessionTest.java
new file mode 100644
index 0000000..9be6375
--- /dev/null
+++ b/android/olm-sdk/src/androidTest/java/org/matrix/olm/OlmGroupSessionTest.java
@@ -0,0 +1,525 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * 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.matrix.olm;
+
+import android.content.Context;
+import android.support.test.runner.AndroidJUnit4;
+import android.text.TextUtils;
+import android.util.Log;
+
+import org.junit.BeforeClass;
+import org.junit.FixMethodOrder;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.MethodSorters;
+
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+import static android.support.test.InstrumentationRegistry.getInstrumentation;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+@RunWith(AndroidJUnit4.class)
+@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+public class OlmGroupSessionTest {
+    private static final String LOG_TAG = "OlmSessionTest";
+    private final String FILE_NAME_SERIAL_OUT_SESSION = "SerialOutGroupSession";
+    private final String FILE_NAME_SERIAL_IN_SESSION = "SerialInGroupSession";
+
+    private static OlmManager mOlmManager;
+    private static OlmOutboundGroupSession mAliceOutboundGroupSession;
+    private static String mAliceSessionIdentifier;
+    private static long mAliceMessageIndex;
+    private static final String CLEAR_MESSAGE1 = "Hello!";
+    private static String mAliceToBobMessage;
+    private static OlmInboundGroupSession mBobInboundGroupSession;
+    private static String mAliceOutboundSessionKey;
+    private static String mBobSessionIdentifier;
+    private static String mBobDecryptedMessage;
+
+    @BeforeClass
+    public static void setUpClass(){
+        // load native lib
+        mOlmManager = new OlmManager();
+
+        String version = mOlmManager.getOlmLibVersion();
+        assertNotNull(version);
+        Log.d(LOG_TAG, "## setUpClass(): lib version="+version);
+    }
+
+    /**
+     * Basic test:
+     * - alice creates an outbound group session
+     * - bob creates an inbound group session with alice's outbound session key
+     * - alice encrypts a message with its session
+     * - bob decrypts the encrypted message with its session
+     * - decrypted message is identical to original alice message
+     */
+    @Test
+    public void test01CreateOutboundSession() {
+        // alice creates OUTBOUND GROUP SESSION
+        try {
+            mAliceOutboundGroupSession = new OlmOutboundGroupSession();
+        } catch (OlmException e) {
+            assertTrue("Exception in OlmOutboundGroupSession, Exception code=" + e.getExceptionCode(), false);
+        }
+    }
+
+    @Test
+    public void test02GetOutboundGroupSessionIdentifier() {
+        // test session ID
+        mAliceSessionIdentifier = null;
+
+        try {
+            mAliceSessionIdentifier = mAliceOutboundGroupSession.sessionIdentifier();
+        } catch (Exception e) {
+            assertTrue(e.getMessage(), false);
+        }
+
+        assertNotNull(mAliceSessionIdentifier);
+        assertTrue(mAliceSessionIdentifier.length() > 0);
+    }
+
+    @Test
+    public void test03GetOutboundGroupSessionKey() {
+        // test session Key
+        mAliceOutboundSessionKey = null;
+
+        try {
+            mAliceOutboundSessionKey = mAliceOutboundGroupSession.sessionKey();
+        } catch (Exception e) {
+            assertTrue(e.getMessage(), false);
+        }
+        assertNotNull(mAliceOutboundSessionKey);
+        assertTrue(mAliceOutboundSessionKey.length() > 0);
+    }
+
+    @Test
+    public void test04GetOutboundGroupMessageIndex() {
+        // test message index before any encryption
+        mAliceMessageIndex = mAliceOutboundGroupSession.messageIndex();
+        assertTrue(0 == mAliceMessageIndex);
+    }
+
+    @Test
+    public void test05OutboundGroupEncryptMessage() {
+        // alice encrypts a message to bob
+        try {
+            mAliceToBobMessage = mAliceOutboundGroupSession.encryptMessage(CLEAR_MESSAGE1);
+        } catch (Exception e) {
+            assertTrue("Exception in bob encryptMessage, Exception code=" + e.getMessage(), false);
+        }
+        assertFalse(TextUtils.isEmpty(mAliceToBobMessage));
+
+        // test message index after encryption is incremented
+        mAliceMessageIndex = mAliceOutboundGroupSession.messageIndex();
+        assertTrue(1 == mAliceMessageIndex);
+    }
+
+    @Test
+    public void test06CreateInboundGroupSession() {
+        // bob creates INBOUND GROUP SESSION with alice outbound key
+        try {
+            mBobInboundGroupSession = new OlmInboundGroupSession(mAliceOutboundSessionKey);
+        } catch (OlmException e) {
+            assertTrue("Exception in bob OlmInboundGroupSession, Exception code=" + e.getExceptionCode(), false);
+        }
+    }
+
+    @Test
+    public void test08GetInboundGroupSessionIdentifier() {
+        // check both session identifiers are equals
+        mBobSessionIdentifier = null;
+
+        try {
+            mBobSessionIdentifier = mBobInboundGroupSession.sessionIdentifier();
+        } catch (Exception e) {
+            assertTrue(e.getMessage(), false);
+        }
+        assertFalse(TextUtils.isEmpty(mBobSessionIdentifier));
+    }
+
+    @Test
+    public void test09SessionIdentifiersAreIdentical() {
+        // check both session identifiers are equals: alice vs bob
+        assertTrue(mAliceSessionIdentifier.equals(mBobSessionIdentifier));
+    }
+
+    @Test
+    public void test10InboundDecryptMessage() {
+        mBobDecryptedMessage = null;
+        OlmInboundGroupSession.DecryptMessageResult result = null;
+
+        try {
+            result = mBobInboundGroupSession.decryptMessage(mAliceToBobMessage);
+        } catch (Exception e) {
+            assertTrue(e.getMessage(), false);
+        }
+
+        // test decrypted message
+        mBobDecryptedMessage = result.mDecryptedMessage;
+        assertFalse(TextUtils.isEmpty(mBobDecryptedMessage));
+        assertTrue(0 == result.mIndex);
+    }
+
+    @Test
+    public void test11InboundDecryptedMessageIdentical() {
+        // test decrypted message
+        assertTrue(mBobDecryptedMessage.equals(CLEAR_MESSAGE1));
+    }
+
+    @Test
+    public void test12ReleaseOutboundSession() {
+        // release group sessions
+        mAliceOutboundGroupSession.releaseSession();
+    }
+
+    @Test
+    public void test13ReleaseInboundSession() {
+        // release group sessions
+        mBobInboundGroupSession.releaseSession();
+    }
+
+    @Test
+    public void test14CheckUnreleaseedCount() {
+        assertTrue(mAliceOutboundGroupSession.isReleased());
+        assertTrue(mBobInboundGroupSession.isReleased());
+    }
+
+    @Test
+    public void test15SerializeOutboundSession() {
+        OlmOutboundGroupSession outboundGroupSessionRef=null;
+        OlmOutboundGroupSession outboundGroupSessionSerial;
+
+        // create one OUTBOUND GROUP SESSION
+        try {
+            outboundGroupSessionRef = new OlmOutboundGroupSession();
+        } catch (OlmException e) {
+            assertTrue("Exception in OlmOutboundGroupSession, Exception code=" + e.getExceptionCode(), false);
+        }
+        assertNotNull(outboundGroupSessionRef);
+
+
+        // serialize alice session
+        Context context = getInstrumentation().getContext();
+        try {
+            FileOutputStream fileOutput = context.openFileOutput(FILE_NAME_SERIAL_OUT_SESSION, Context.MODE_PRIVATE);
+            ObjectOutputStream objectOutput = new ObjectOutputStream(fileOutput);
+            objectOutput.writeObject(outboundGroupSessionRef);
+            objectOutput.flush();
+            objectOutput.close();
+
+            // deserialize session
+            FileInputStream fileInput = context.openFileInput(FILE_NAME_SERIAL_OUT_SESSION);
+            ObjectInputStream objectInput = new ObjectInputStream(fileInput);
+            outboundGroupSessionSerial = (OlmOutboundGroupSession) objectInput.readObject();
+            assertNotNull(outboundGroupSessionSerial);
+            objectInput.close();
+
+            // get sessions keys
+            String sessionKeyRef = outboundGroupSessionRef.sessionKey();
+            String sessionKeySerial = outboundGroupSessionSerial.sessionKey();
+            assertFalse(TextUtils.isEmpty(sessionKeyRef));
+            assertFalse(TextUtils.isEmpty(sessionKeySerial));
+
+            // session keys comparison
+            assertTrue(sessionKeyRef.equals(sessionKeySerial));
+
+            // get sessions IDs
+            String sessionIdRef = outboundGroupSessionRef.sessionIdentifier();
+            String sessionIdSerial = outboundGroupSessionSerial.sessionIdentifier();
+            assertFalse(TextUtils.isEmpty(sessionIdRef));
+            assertFalse(TextUtils.isEmpty(sessionIdSerial));
+
+            // session IDs comparison
+            assertTrue(sessionIdRef.equals(sessionIdSerial));
+
+            outboundGroupSessionRef.releaseSession();
+            outboundGroupSessionSerial.releaseSession();
+
+            assertTrue(outboundGroupSessionRef.isReleased());
+            assertTrue(outboundGroupSessionSerial.isReleased());
+        } catch (FileNotFoundException e) {
+            Log.e(LOG_TAG, "## test15SerializeOutboundSession(): Exception FileNotFoundException Msg=="+e.getMessage());
+            assertTrue(e.getMessage(), false);
+        } catch (ClassNotFoundException e) {
+            Log.e(LOG_TAG, "## test15SerializeOutboundSession(): Exception ClassNotFoundException Msg==" + e.getMessage());
+            assertTrue(e.getMessage(), false);
+        } catch (OlmException e) {
+            Log.e(LOG_TAG, "## test15SerializeOutboundSession(): Exception OlmException Msg==" + e.getMessage());
+            assertTrue(e.getMessage(), false);
+        } catch (IOException e) {
+            Log.e(LOG_TAG, "## test15SerializeOutboundSession(): Exception IOException Msg==" + e.getMessage());
+            assertTrue(e.getMessage(), false);
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## test15SerializeOutboundSession(): Exception Msg==" + e.getMessage());
+            assertTrue(e.getMessage(), false);
+        }
+    }
+
+    @Test
+    public void test16SerializeInboundSession() {
+        OlmOutboundGroupSession aliceOutboundGroupSession=null;
+        OlmInboundGroupSession bobInboundGroupSessionRef=null;
+        OlmInboundGroupSession bobInboundGroupSessionSerial;
+
+        // alice creates OUTBOUND GROUP SESSION
+        try {
+            aliceOutboundGroupSession = new OlmOutboundGroupSession();
+        } catch (OlmException e) {
+            assertTrue("Exception in OlmOutboundGroupSession, Exception code=" + e.getExceptionCode(), false);
+        }
+        assertNotNull(aliceOutboundGroupSession);
+
+        // get the session key from the outbound group session
+        String sessionKeyRef = null;
+
+        try {
+            sessionKeyRef = aliceOutboundGroupSession.sessionKey();
+        } catch (Exception e) {
+            assertTrue(e.getMessage(), false);
+        }
+        assertNotNull(sessionKeyRef);
+
+        // bob creates INBOUND GROUP SESSION
+        try {
+            bobInboundGroupSessionRef = new OlmInboundGroupSession(sessionKeyRef);
+        } catch (OlmException e) {
+            assertTrue("Exception in OlmInboundGroupSession, Exception code=" + e.getExceptionCode(), false);
+        }
+        assertNotNull(bobInboundGroupSessionRef);
+
+        // serialize alice session
+        Context context = getInstrumentation().getContext();
+        try {
+            FileOutputStream fileOutput = context.openFileOutput(FILE_NAME_SERIAL_IN_SESSION, Context.MODE_PRIVATE);
+            ObjectOutputStream objectOutput = new ObjectOutputStream(fileOutput);
+            objectOutput.writeObject(bobInboundGroupSessionRef);
+            objectOutput.flush();
+            objectOutput.close();
+
+            // deserialize session
+            FileInputStream fileInput = context.openFileInput(FILE_NAME_SERIAL_IN_SESSION);
+            ObjectInputStream objectInput = new ObjectInputStream(fileInput);
+            bobInboundGroupSessionSerial = (OlmInboundGroupSession)objectInput.readObject();
+            assertNotNull(bobInboundGroupSessionSerial);
+            objectInput.close();
+
+            // get sessions IDs
+            String aliceSessionId = aliceOutboundGroupSession.sessionIdentifier();
+            String sessionIdRef = bobInboundGroupSessionRef.sessionIdentifier();
+            String sessionIdSerial = bobInboundGroupSessionSerial.sessionIdentifier();
+            assertFalse(TextUtils.isEmpty(aliceSessionId));
+            assertFalse(TextUtils.isEmpty(sessionIdRef));
+            assertFalse(TextUtils.isEmpty(sessionIdSerial));
+
+            // session IDs comparison
+            assertTrue(aliceSessionId.equals(sessionIdSerial));
+            assertTrue(sessionIdRef.equals(sessionIdSerial));
+
+            aliceOutboundGroupSession.releaseSession();
+            bobInboundGroupSessionRef.releaseSession();
+            bobInboundGroupSessionSerial.releaseSession();
+
+            assertTrue(aliceOutboundGroupSession.isReleased());
+            assertTrue(bobInboundGroupSessionRef.isReleased());
+            assertTrue(bobInboundGroupSessionSerial.isReleased());
+        } catch (FileNotFoundException e) {
+            Log.e(LOG_TAG, "## test16SerializeInboundSession(): Exception FileNotFoundException Msg=="+e.getMessage());
+            assertTrue(e.getMessage(), false);
+        } catch (ClassNotFoundException e) {
+            Log.e(LOG_TAG, "## test16SerializeInboundSession(): Exception ClassNotFoundException Msg==" + e.getMessage());
+            assertTrue(e.getMessage(), false);
+        } catch (OlmException e) {
+            Log.e(LOG_TAG, "## test16SerializeInboundSession(): Exception OlmException Msg==" + e.getMessage());
+            assertTrue(e.getMessage(), false);
+        } catch (IOException e) {
+            Log.e(LOG_TAG, "## test16SerializeInboundSession(): Exception IOException Msg==" + e.getMessage());
+            assertTrue(e.getMessage(), false);
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## test16SerializeInboundSession(): Exception Msg==" + e.getMessage());
+            assertTrue(e.getMessage(), false);
+        }
+    }
+
+    /**
+     * Create multiple outbound group sessions and check that session Keys are different.
+     * This test validates random series are provide enough random values.
+     */
+    @Test
+    public void test17MultipleOutboundSession() {
+        OlmOutboundGroupSession outboundGroupSession1;
+        OlmOutboundGroupSession outboundGroupSession2;
+        OlmOutboundGroupSession outboundGroupSession3;
+        OlmOutboundGroupSession outboundGroupSession4;
+        OlmOutboundGroupSession outboundGroupSession5;
+        OlmOutboundGroupSession outboundGroupSession6;
+        OlmOutboundGroupSession outboundGroupSession7;
+        OlmOutboundGroupSession outboundGroupSession8;
+
+        try {
+            outboundGroupSession1 = new OlmOutboundGroupSession();
+            outboundGroupSession2 = new OlmOutboundGroupSession();
+            outboundGroupSession3 = new OlmOutboundGroupSession();
+            outboundGroupSession4 = new OlmOutboundGroupSession();
+            outboundGroupSession5 = new OlmOutboundGroupSession();
+            outboundGroupSession6 = new OlmOutboundGroupSession();
+            outboundGroupSession7 = new OlmOutboundGroupSession();
+            outboundGroupSession8 = new OlmOutboundGroupSession();
+
+            // get the session key from the outbound group sessions
+            String sessionKey1 = outboundGroupSession1.sessionKey();
+            String sessionKey2 = outboundGroupSession2.sessionKey();
+            assertFalse(sessionKey1.equals(sessionKey2));
+
+            String sessionKey3 = outboundGroupSession3.sessionKey();
+            assertFalse(sessionKey2.equals(sessionKey3));
+
+            String sessionKey4 = outboundGroupSession4.sessionKey();
+            assertFalse(sessionKey3.equals(sessionKey4));
+
+            String sessionKey5 = outboundGroupSession5.sessionKey();
+            assertFalse(sessionKey4.equals(sessionKey5));
+
+            String sessionKey6 = outboundGroupSession6.sessionKey();
+            assertFalse(sessionKey5.equals(sessionKey6));
+
+            String sessionKey7 = outboundGroupSession7.sessionKey();
+            assertFalse(sessionKey6.equals(sessionKey7));
+
+            String sessionKey8 = outboundGroupSession8.sessionKey();
+            assertFalse(sessionKey7.equals(sessionKey8));
+
+            // get the session IDs from the outbound group sessions
+            String sessionId1 = outboundGroupSession1.sessionIdentifier();
+            String sessionId2 = outboundGroupSession2.sessionIdentifier();
+            assertFalse(sessionId1.equals(sessionId2));
+
+            String sessionId3 = outboundGroupSession3.sessionKey();
+            assertFalse(sessionId2.equals(sessionId3));
+
+            String sessionId4 = outboundGroupSession4.sessionKey();
+            assertFalse(sessionId3.equals(sessionId4));
+
+            String sessionId5 = outboundGroupSession5.sessionKey();
+            assertFalse(sessionId4.equals(sessionId5));
+
+            String sessionId6 = outboundGroupSession6.sessionKey();
+            assertFalse(sessionId5.equals(sessionId6));
+
+            String sessionId7 = outboundGroupSession7.sessionKey();
+            assertFalse(sessionId6.equals(sessionId7));
+
+            String sessionId8 = outboundGroupSession8.sessionKey();
+            assertFalse(sessionId7.equals(sessionId8));
+
+            outboundGroupSession1.releaseSession();
+            outboundGroupSession2.releaseSession();
+            outboundGroupSession3.releaseSession();
+            outboundGroupSession4.releaseSession();
+            outboundGroupSession5.releaseSession();
+            outboundGroupSession6.releaseSession();
+            outboundGroupSession7.releaseSession();
+            outboundGroupSession8.releaseSession();
+
+            assertTrue(outboundGroupSession1.isReleased());
+            assertTrue(outboundGroupSession2.isReleased());
+            assertTrue(outboundGroupSession3.isReleased());
+            assertTrue(outboundGroupSession4.isReleased());
+            assertTrue(outboundGroupSession5.isReleased());
+            assertTrue(outboundGroupSession6.isReleased());
+            assertTrue(outboundGroupSession7.isReleased());
+            assertTrue(outboundGroupSession8.isReleased());
+        } catch (OlmException e) {
+            assertTrue("Exception in OlmOutboundGroupSession, Exception code=" + e.getExceptionCode(), false);
+        }
+    }
+
+    /**
+     * Specific test for the following run time error:
+     * "JNI DETECTED ERROR IN APPLICATION: input is not valid Modified UTF-8: illegal start byte 0xf0 in call to NewStringUTF".<br>
+     * When the msg to decrypt contain emojis, depending on the android platform, the NewStringUTF() behaves differently and
+     * can even crash.
+     * This issue is described in details here: https://github.com/eclipsesource/J2V8/issues/142
+     */
+    @Test
+    public void test18TestBadCharacterCrashInDecrypt() {
+        OlmInboundGroupSession bobInboundGroupSession=null;
+
+        // values taken from a "real life" crash case
+        String sessionKeyRef = "AgAAAAycZE6AekIctJWYxd2AWLOY15YmxZODm/WkgbpWkyycp6ytSp/R+wo84jRrzBNWmv6ySLTZ9R0EDOk9VI2eZyQ6Efdwyo1mAvrWvTkZl9yALPdkOIVHywyG65f1SNiLrnsln3hgsT1vUrISGyKtsljoUgQpr3JDPEhD0ilAi63QBjhnGCW252b+7nF+43rb6O6lwm93LaVwe2341Gdp6EkhTUvetALezEqDOtKN00wVqAbq0RQAnUJIowxHbMswg+FyoR1K1oCjnVEoF23O9xlAn5g1XtuBZP3moJlR2lwsBA";
+        String msgToDecryptWithEmoji = "AwgNEpABpjs+tYF+0y8bWtzAgYAC3N55p5cPJEEiGPU1kxIHSY7f2aG5Fj4wmcsXUkhDv0UePj922kgf+Q4dFsPHKq2aVA93n8DJAQ/FRfcM98B9E6sKCZ/PsCF78uBvF12Aaq9D3pUHBopdd7llUfVq29d5y6ZwX5VDoqV2utsATkKjXYV9CbfZuvvBMQ30ZLjEtyUUBJDY9K4FxEFcULytA/IkVnATTG9ERuLF/yB6ukSFR+iUWRYAmtuOuU0k9BvaqezbGqNoK5Grlkes+dYX6/0yUObumcw9/iAI";
+
+        // bob creates INBOUND GROUP SESSION
+        try {
+            bobInboundGroupSession = new OlmInboundGroupSession(sessionKeyRef);
+        } catch (OlmException e) {
+            assertTrue("Exception in test18TestBadCharacterCrashInDecrypt, Exception code=" + e.getExceptionCode(), false);
+        }
+
+        OlmInboundGroupSession.DecryptMessageResult result = null;
+
+        try {
+            result = bobInboundGroupSession.decryptMessage(msgToDecryptWithEmoji);
+        } catch (Exception e) {
+            assertTrue("Exception in test18TestBadCharacterCrashInDecrypt, Exception code=" + e.getMessage(), false);
+        }
+
+        assertNotNull(result.mDecryptedMessage);
+        assertTrue(13 == result.mIndex);
+    }
+
+    /**
+     * Specific test to check an error message is returned by decryptMessage() API.<br>
+     * A corrupted encrypted message is passed, and a INVALID_BASE64 is
+     * espexted.
+    **/
+    @Test
+    public void test19TestErrorMessageReturnedInDecrypt() {
+        OlmInboundGroupSession bobInboundGroupSession=null;
+        final String EXPECTED_ERROR_MESSAGE= "INVALID_BASE64";
+
+        String sessionKeyRef    = "AgAAAAycZE6AekIctJWYxd2AWLOY15YmxZODm/WkgbpWkyycp6ytSp/R+wo84jRrzBNWmv6ySLTZ9R0EDOk9VI2eZyQ6Efdwyo1mAvrWvTkZl9yALPdkOIVHywyG65f1SNiLrnsln3hgsT1vUrISGyKtsljoUgQpr3JDPEhD0ilAi63QBjhnGCW252b+7nF+43rb6O6lwm93LaVwe2341Gdp6EkhTUvetALezEqDOtKN00wVqAbq0RQAnUJIowxHbMswg+FyoR1K1oCjnVEoF23O9xlAn5g1XtuBZP3moJlR2lwsBA";
+        String corruptedEncryptedMsg = "AwgANYTHINGf87ge45ge7gr*/rg5ganything4gr41rrgr4re55tanythingmcsXUkhDv0UePj922kgf+";
+
+        // valid INBOUND GROUP SESSION
+        try {
+            bobInboundGroupSession = new OlmInboundGroupSession(sessionKeyRef);
+        } catch (OlmException e) {
+            assertTrue("Exception in test19TestErrorMessageReturnedInDecrypt, Exception code=" + e.getExceptionCode(), false);
+        }
+
+        String exceptionMessage = null;
+        try {
+            bobInboundGroupSession.decryptMessage(corruptedEncryptedMsg);
+        } catch (OlmException e) {
+            exceptionMessage = e.getMessage();
+        }
+
+        assertTrue(0!=EXPECTED_ERROR_MESSAGE.length());
+        assertTrue(EXPECTED_ERROR_MESSAGE.equals(exceptionMessage));
+    }
+}
+