Merge pull request #43 from matrix-org/pedroc/android_e2e_dev

Android wrappers for olm library

android/olm-sdk/src/main/java/org/matrix/olm/OlmInboundGroupSession.java

+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 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.text.TextUtils;
+import android.util.Log;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+
+/**
+ * Class used to create an inbound <a href="http://matrix.org/docs/guides/e2e_implementation.html#handling-an-m-room-key-event">Megolm session</a>.<br>
+ * Counter part of the outbound group session {@link OlmOutboundGroupSession}, this class decrypts the messages sent by the outbound side.
+ *
+ * <br><br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmInboundGroupSession extends CommonSerializeUtils implements Serializable {
+    private static final long serialVersionUID = -772028491251653253L;
+    private static final String LOG_TAG = "OlmInboundGroupSession";
+
+    /** Session Id returned by JNI.<br>
+     * This value uniquely identifies the native inbound group session instance.
+     */
+    private transient long mNativeId;
+
+    /**
+     * Result in {@link #decryptMessage(String)}
+     */
+    public static class DecryptMessageResult {
+        /** decrypt message **/
+        public String mDecryptedMessage;
+
+        /** decrypt index **/
+        public long mIndex;
+    }
+
+    /**
+     * Constructor.<br>
+     * Create and save a new native session instance ID and start a new inbound group session.
+     * The session key parameter is retrieved from an outbound group session.
+     * @param aSessionKey session key
+     * @throws OlmException constructor failure
+     */
+    public OlmInboundGroupSession(String aSessionKey) throws OlmException {
+        if (TextUtils.isEmpty(aSessionKey)) {
+            Log.e(LOG_TAG, "## initInboundGroupSession(): invalid session key");
+            throw new OlmException(OlmException.EXCEPTION_CODE_INIT_INBOUND_GROUP_SESSION, "invalid session key");
+        } else {
+            try {
+                mNativeId = createNewSessionJni(aSessionKey.getBytes("UTF-8"));
+            } catch (Exception e) {
+                throw new OlmException(OlmException.EXCEPTION_CODE_INIT_INBOUND_GROUP_SESSION, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Initialize a new inbound group session and return it to JAVA side.<br>
+     * Since a C prt is returned as a jlong, special care will be taken
+     * to make the cast (OlmInboundGroupSession* to jlong) platform independent.
+     * @param aSessionKeyBuffer session key from an outbound session
+     * @return the initialized OlmInboundGroupSession* instance or throw an exception it fails.
+     **/
+    private native long createNewSessionJni(byte[] aSessionKeyBuffer);
+
+    /**
+     * Release native session and invalid its JAVA reference counter part.<br>
+     * Public API for {@link #releaseSessionJni()}.
+     */
+    public void releaseSession(){
+        if (0 != mNativeId) {
+            releaseSessionJni();
+        }
+        mNativeId = 0;
+    }
+
+    /**
+     * Destroy the corresponding OLM inbound group session native object.<br>
+     * This method must ALWAYS be called when this JAVA instance
+     * is destroyed (ie. garbage collected) to prevent memory leak in native side.
+     * See {@link #createNewSessionJni(byte[])}.
+     */
+    private native void releaseSessionJni();
+
+    /**
+     * Return true the object resources have been released.<br>
+     * @return true the object resources have been released
+     */
+    public boolean isReleased() {
+        return (0 == mNativeId);
+    }
+
+    /**
+     * Retrieve the base64-encoded identifier for this inbound group session.
+     * @return the session ID
+     * @throws OlmException the failure reason
+     */
+    public String sessionIdentifier() throws OlmException {
+        try {
+            return new String(sessionIdentifierJni(), "UTF-8");
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## sessionIdentifier() failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_INBOUND_GROUP_SESSION_IDENTIFIER, e.getMessage());
+        }
+    }
+
+    /**
+     * Get a base64-encoded identifier for this inbound group session.
+     * An exception is thrown if the operation fails.
+     * @return the base64-encoded identifier
+     */
+    private native byte[] sessionIdentifierJni();
+
+    /**
+     * Decrypt the message passed in parameter.<br>
+     * In case of error, null is returned and an error message description is provided in aErrorMsg.
+     * @param aEncryptedMsg the message to be decrypted
+     * @return the decrypted message information
+     * @exception OlmException teh failure reason
+     */
+    public DecryptMessageResult decryptMessage(String aEncryptedMsg) throws OlmException {
+        DecryptMessageResult result = new DecryptMessageResult();
+
+        try {
+            byte[] decryptedMessageBuffer = decryptMessageJni(aEncryptedMsg.getBytes("UTF-8"), result);
+
+            if (null != decryptedMessageBuffer) {
+                result.mDecryptedMessage = new String(decryptedMessageBuffer, "UTF-8");
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## decryptMessage() failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_INBOUND_GROUP_SESSION_DECRYPT_SESSION, e.getMessage());
+        }
+
+        return result;
+    }
+
+    /**
+     * Decrypt a message.
+     * An exception is thrown if the operation fails.
+     * @param aEncryptedMsg the encrypted message
+     * @param aDecryptMessageResult the decryptMessage informaton
+     * @return the decrypted message
+     */
+    private native byte[] decryptMessageJni(byte[] aEncryptedMsg, DecryptMessageResult aDecryptMessageResult);
+
+    //==============================================================================================================
+    // Serialization management
+    //==============================================================================================================
+
+    /**
+     * Kick off the serialization mechanism.
+     * @param aOutStream output stream for serializing
+     * @throws IOException exception
+     */
+    private void writeObject(ObjectOutputStream aOutStream) throws IOException {
+        serialize(aOutStream);
+    }
+
+    /**
+     * Kick off the deserialization mechanism.
+     * @param aInStream input stream
+     * @throws Exception exception
+     */
+    private void readObject(ObjectInputStream aInStream) throws Exception {
+        deserialize(aInStream);
+    }
+
+    /**
+     * Return the current inbound group session as a bytes buffer.<br>
+     * The session is serialized and encrypted with aKey.
+     * In case of failure, an error human readable
+     * description is provide in aErrorMsg.
+     * @param aKey encryption key
+     * @param aErrorMsg error message description
+     * @return pickled bytes buffer if operation succeed, null otherwise
+     */
+    @Override
+    protected byte[] serialize(byte[] aKey, StringBuffer aErrorMsg) {
+        byte[] pickleRetValue = null;
+
+        // sanity check
+        if(null == aErrorMsg) {
+            Log.e(LOG_TAG,"## serialize(): invalid parameter - aErrorMsg=null");
+            aErrorMsg.append("aErrorMsg=null");
+        } else if (null == aKey) {
+            aErrorMsg.append("Invalid input parameters in serialize()");
+        } else {
+            aErrorMsg.setLength(0);
+            try {
+                pickleRetValue = serializeJni(aKey);
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## serialize() failed " + e.getMessage());
+                aErrorMsg.append(e.getMessage());
+            }
+        }
+
+        return pickleRetValue;
+    }
+    /**
+     * JNI counter part of {@link #serialize(byte[], StringBuffer)}.
+     * @param aKey encryption key
+     * @return the serialized session
+     */
+    private native byte[] serializeJni(byte[] aKey);
+
+    /**
+     * Loads an account from a pickled base64 string.<br>
+     * See {@link #serialize(byte[], StringBuffer)}
+     * @param aSerializedData pickled account in a bytes buffer
+     * @param aKey key used to encrypted
+     */
+    @Override
+    protected void deserialize(byte[] aSerializedData, byte[] aKey) throws Exception {
+        String errorMsg = null;
+
+        try {
+            if ((null == aSerializedData) || (null == aKey)) {
+                Log.e(LOG_TAG, "## deserialize(): invalid input parameters");
+                errorMsg = "invalid input parameters";
+            } else {
+                mNativeId = deserializeJni(aSerializedData, aKey);
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## deserialize() failed " + e.getMessage());
+            errorMsg = e.getMessage();
+        }
+
+        if (!TextUtils.isEmpty(errorMsg)) {
+            releaseSession();
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_DESERIALIZATION, errorMsg);
+        }
+    }
+
+    /**
+     * Allocate a new session and initialize it with the serialisation data.<br>
+     * An exception is thrown if the operation fails.
+     * @param aSerializedData the session serialisation buffer
+     * @param aKey the key used to encrypt the serialized account data
+     * @return the deserialized session
+     **/
+    private native long deserializeJni(byte[] aSerializedData, byte[] aKey);
+}

android/olm-sdk/src/main/java/org/matrix/olm/OlmManager.java

+/*
+ * 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.util.Log;
+
+/**
+ * Olm SDK entry point class.<br> An OlmManager instance must be created at first to enable native library load.
+ * <br><br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmManager {
+    private static final String LOG_TAG = "OlmManager";
+
+    /**
+     * Constructor.
+     */
+    public OlmManager() {
+    }
+
+    static {
+        try {
+            java.lang.System.loadLibrary("olm");
+        } catch(UnsatisfiedLinkError e) {
+            Log.e(LOG_TAG,"Exception loadLibrary() - Msg="+e.getMessage());
+        }
+    }
+
+    /**
+     * Provide the android library version
+     * @param context the context
+     * @return the library version
+     */
+    public String getSdkOlmVersion(Context context) {
+        String gitVersion = context.getResources().getString(R.string.git_olm_revision);
+        String date = context.getResources().getString(R.string.git_olm_revision_date);
+        return gitVersion + "-" + date;
+    }
+
+    /**
+     * Get the OLM lib version.
+     * @return the lib version as a string
+     */
+    public String getOlmLibVersion(){
+        return getOlmLibVersionJni();
+    }
+    public native String getOlmLibVersionJni();
+}
+

android/olm-sdk/src/main/java/org/matrix/olm/OlmMessage.java

+/*
+ * 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;
+
+/**
+ * Message class used in Olm sessions to contain the encrypted data.<br>
+ * See {@link OlmSession#decryptMessage(OlmMessage)} and {@link OlmSession#encryptMessage(String)}.
+ * <br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmMessage {
+    /** PRE KEY message type (used to establish new Olm session) **/
+    public final static int MESSAGE_TYPE_PRE_KEY = 0;
+    /** normal message type **/
+    public final static int MESSAGE_TYPE_MESSAGE = 1;
+
+    /** the encrypted message **/
+    public String mCipherText;
+
+    /** defined by {@link #MESSAGE_TYPE_MESSAGE} or {@link #MESSAGE_TYPE_PRE_KEY}**/
+    public long mType;
+}

android/olm-sdk/src/main/java/org/matrix/olm/OlmOutboundGroupSession.java

+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 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.text.TextUtils;
+import android.util.Log;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+
+/**
+ * Class used to create an outbound a <a href="http://matrix.org/docs/guides/e2e_implementation.html#starting-a-megolm-session">Megolm session</a>.<br>
+ * To send a first message in an encrypted room, the client should start a new outbound Megolm session.
+ * The session ID and the session key must be shared with each device in the room within.
+ *
+ * <br><br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmOutboundGroupSession extends CommonSerializeUtils implements Serializable {
+    private static final long serialVersionUID = -3133097431283604416L;
+    private static final String LOG_TAG = "OlmOutboundGroupSession";
+
+    /** Session Id returned by JNI.<br>
+     * This value uniquely identifies the native outbound group session instance.
+     */
+    private transient long mNativeId;
+
+    /**
+     * Constructor.<br>
+     * Create and save a new session native instance ID and
+     * initialise a new outbound group session.<br>
+     * @throws OlmException constructor failure
+     */
+    public OlmOutboundGroupSession() throws OlmException {
+        try {
+            mNativeId = createNewSessionJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_CREATE_OUTBOUND_GROUP_SESSION, e.getMessage());
+        }
+    }
+
+    /**
+     * Create the corresponding OLM outbound group session in native side.<br>
+     * An exception is thrown if the operation fails.
+     * Do not forget to call {@link #releaseSession()} when JAVA side is done.
+     * @return native session instance identifier (see {@link #mNativeId})
+     */
+    private native long createNewSessionJni();
+
+    /**
+     * Release native session and invalid its JAVA reference counter part.<br>
+     * Public API for {@link #releaseSessionJni()}.
+     */
+    public void releaseSession() {
+        if (0 != mNativeId) {
+            releaseSessionJni();
+        }
+        mNativeId = 0;
+    }
+
+    /**
+     * Destroy the corresponding OLM outbound group session native object.<br>
+     * This method must ALWAYS be called when this JAVA instance
+     * is destroyed (ie. garbage collected) to prevent memory leak in native side.
+     * See {@link #createNewSessionJni()}.
+     */
+    private native void releaseSessionJni();
+
+    /**
+     * Return true the object resources have been released.<br>
+     * @return true the object resources have been released
+     */
+    public boolean isReleased() {
+        return (0 == mNativeId);
+    }
+
+    /**
+     * Get a base64-encoded identifier for this session.
+     * @return session identifier
+     * @throws OlmException the failure reason
+     */
+    public String sessionIdentifier() throws OlmException {
+        try {
+            return new String(sessionIdentifierJni(), "UTF-8");
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## sessionIdentifier() failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_OUTBOUND_GROUP_SESSION_IDENTIFIER, e.getMessage());
+        }
+    }
+
+    /**
+     * Return the session identifier.
+     * An exception is thrown if the operation fails.
+     * @return the session identifier
+     */
+    private native byte[] sessionIdentifierJni();
+
+    /**
+     * Get the current message index for this session.<br>
+     * Each message is sent with an increasing index, this
+     * method returns the index for the next message.
+     * @return current session index
+     */
+    public int messageIndex() {
+        return messageIndexJni();
+    }
+
+    /**
+     * Get the current message index for this session.<br>
+     * Each message is sent with an increasing index, this
+     * method returns the index for the next message.
+     * An exception is thrown if the operation fails.
+     * @return current session index
+     */
+    private native int messageIndexJni();
+
+    /**
+     * Get the base64-encoded current ratchet key for this session.<br>
+     * Each message is sent with a different ratchet key. This method returns the
+     * ratchet key that will be used for the next message.
+     * @return outbound session key
+     * @exception OlmException the failure reason
+     */
+    public String sessionKey() throws OlmException {
+        try {
+            return new String(sessionKeyJni(), "UTF-8");
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## sessionKey() failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_OUTBOUND_GROUP_SESSION_KEY, e.getMessage());
+        }
+    }
+
+    /**
+     * Return the session key.
+     * An exception is thrown if the operation fails.
+     * @return the session key
+     */
+    private native byte[] sessionKeyJni();
+
+    /**
+     * Encrypt some plain-text message.<br>
+     * The message given as parameter is encrypted and returned as the return value.
+     * @param aClearMsg message to be encrypted
+     * @return the encrypted message
+     * @exception OlmException the encryption failure reason
+     */
+    public String encryptMessage(String aClearMsg) throws OlmException {
+        String retValue = null;
+
+        if (!TextUtils.isEmpty(aClearMsg)) {
+            try {
+                byte[] encryptedBuffer = encryptMessageJni(aClearMsg.getBytes("UTF-8"));
+
+                if (null != encryptedBuffer) {
+                    retValue = new String(encryptedBuffer , "UTF-8");
+                }
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## encryptMessage() failed " + e.getMessage());
+                throw new OlmException(OlmException.EXCEPTION_CODE_OUTBOUND_GROUP_ENCRYPT_MESSAGE, e.getMessage());
+            }
+        }
+
+        return retValue;
+    }
+
+    /**
+     * Encrypt a bytes buffer messages.
+     * An exception is thrown if the operation fails.
+     * @param aClearMsgBuffer  the message to encode
+     * @return the encoded message
+     */
+    private native byte[] encryptMessageJni(byte[] aClearMsgBuffer);
+
+    //==============================================================================================================
+    // Serialization management
+    //==============================================================================================================
+
+    /**
+     * Kick off the serialization mechanism.
+     * @param aOutStream output stream for serializing
+     * @throws IOException exception
+     */
+    private void writeObject(ObjectOutputStream aOutStream) throws IOException {
+        serialize(aOutStream);
+    }
+
+    /**
+     * Kick off the deserialization mechanism.
+     * @param aInStream input stream
+     * @throws Exception exception
+     */
+    private void readObject(ObjectInputStream aInStream) throws Exception {
+        deserialize(aInStream);
+    }
+
+    /**
+     * Return the current outbound group session as a base64 byte buffers.<br>
+     * The session is serialized and encrypted with aKey.
+     * In case of failure, an error human readable
+     * description is provide in aErrorMsg.
+     * @param aKey encryption key
+     * @param aErrorMsg error message description
+     * @return pickled base64 bytes buffer if operation succeed, null otherwise
+     */
+    @Override
+    protected byte[] serialize(byte[] aKey, StringBuffer aErrorMsg) {
+        byte[] pickleRetValue = null;
+
+        // sanity check
+        if(null == aErrorMsg) {
+            Log.e(LOG_TAG,"## serialize(): invalid parameter - aErrorMsg=null");
+        } else if (null == aKey) {
+            aErrorMsg.append("Invalid input parameters in serialize()");
+        } else {
+            try {
+                pickleRetValue = serializeJni(aKey);
+            } catch (Exception e) {
+                Log.e(LOG_TAG,"## serialize(): failed " + e.getMessage());
+                aErrorMsg.append(e.getMessage());
+            }
+        }
+
+        return pickleRetValue;
+    }
+
+    /**
+     * JNI counter part of {@link #serialize(byte[], StringBuffer)}.
+     * An exception is thrown if the operation fails.
+     * @param aKey encryption key
+     * @return the serialized session
+     */
+    private native byte[] serializeJni(byte[] aKey);
+
+    /**
+     * Loads an account from a pickled base64 string.<br>
+     * See {@link #serialize(byte[], StringBuffer)}
+     * @param aSerializedData pickled account in a base64 bytes buffer
+     * @param aKey key used to encrypted
+     * @exception Exception the exception
+     */
+    @Override
+    protected void deserialize(byte[] aSerializedData, byte[] aKey) throws Exception {
+        String errorMsg = null;
+
+        try {
+            if ((null == aSerializedData) || (null == aKey)) {
+                Log.e(LOG_TAG, "## deserialize(): invalid input parameters");
+                errorMsg = "invalid input parameters";
+            } else {
+                mNativeId = deserializeJni(aSerializedData, aKey);
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## deserialize() failed " + e.getMessage());
+            errorMsg = e.getMessage();
+        }
+
+        if (!TextUtils.isEmpty(errorMsg)) {
+            releaseSession();
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_DESERIALIZATION, errorMsg);
+        }
+    }
+
+    /**
+     * Allocate a new session and initialize it with the serialisation data.<br>
+     * An exception is thrown if the operation fails.
+     * @param aSerializedData the session serialisation buffer
+     * @param aKey the key used to encrypt the serialized account data
+     * @return the deserialized session
+     **/
+    private native long deserializeJni(byte[] aSerializedData, byte[] aKey);
+
+}

android/olm-sdk/src/main/java/org/matrix/olm/OlmSession.java

+/*
+ * 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.text.TextUtils;
+import android.util.Log;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+
+/**
+ * Session class used to create Olm sessions in conjunction with {@link OlmAccount} class.<br>
+ * Olm session is used to encrypt data between devices, especially to create Olm group sessions (see {@link OlmOutboundGroupSession} and {@link OlmInboundGroupSession}).<br>
+ * To establish an Olm session with Bob, Alice calls {@link #initOutboundSession(OlmAccount, String, String)} with Bob's identity and onetime keys. Then Alice generates an encrypted PRE_KEY message ({@link #encryptMessage(String)})
+ * used by Bob to open the Olm session in his side with {@link #initOutboundSession(OlmAccount, String, String)}.
+ * From this step on, messages can be exchanged by using {@link #encryptMessage(String)} and {@link #decryptMessage(OlmMessage)}.
+ * <br><br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmSession extends CommonSerializeUtils implements Serializable {
+    private static final long serialVersionUID = -8975488639186976419L;
+    private static final String LOG_TAG = "OlmSession";
+
+    /** Session Id returned by JNI.
+     * This value uniquely identifies the native session instance.
+     **/
+    private transient long mNativeId;
+
+    public OlmSession() throws OlmException {
+        try {
+            mNativeId = createNewSessionJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_INIT_SESSION_CREATION, e.getMessage());
+        }
+    }
+
+    /**
+     * Create an OLM session in native side.<br>
+     * Do not forget to call {@link #releaseSession()} when JAVA side is done.
+     * @return native account instance identifier or throw an exception.
+     */
+    private native long createNewSessionJni();
+
+    /**
+     * Getter on the session ID.
+     * @return native session ID
+     */
+    long getOlmSessionId(){
+        return mNativeId;
+    }
+
+    /**
+     * Destroy the corresponding OLM session native object.<br>
+     * This method must ALWAYS be called when this JAVA instance
+     * is destroyed (ie. garbage collected) to prevent memory leak in native side.
+     * See {@link #createNewSessionJni()}.
+     */
+    private native void releaseSessionJni();
+
+    /**
+     * Release native session and invalid its JAVA reference counter part.<br>
+     * Public API for {@link #releaseSessionJni()}.
+     */
+    public void releaseSession() {
+        if (0 != mNativeId) {
+            releaseSessionJni();
+        }
+        mNativeId = 0;
+    }
+
+    /**
+     * Return true the object resources have been released.<br>
+     * @return true the object resources have been released
+     */
+    public boolean isReleased() {
+        return (0 == mNativeId);
+    }
+
+    /**
+     * Creates a new out-bound session for sending messages to a recipient
+     * identified by an identity key and a one time key.<br>
+     * @param aAccount the account to associate with this session
+     * @param aTheirIdentityKey the identity key of the recipient
+     * @param aTheirOneTimeKey the one time key of the recipient
+     * @exception OlmException the failure reason
+     */
+    public void initOutboundSession(OlmAccount aAccount, String aTheirIdentityKey, String aTheirOneTimeKey) throws OlmException {
+        if ((null == aAccount) || TextUtils.isEmpty(aTheirIdentityKey) || TextUtils.isEmpty(aTheirOneTimeKey)) {
+            Log.e(LOG_TAG, "## initOutboundSession(): invalid input parameters");
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_OUTBOUND_SESSION, "invalid input parameters");
+        } else {
+            try {
+                initOutboundSessionJni(aAccount.getOlmAccountId(), aTheirIdentityKey.getBytes("UTF-8"), aTheirOneTimeKey.getBytes("UTF-8"));
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## initOutboundSession(): " + e.getMessage());
+                throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_OUTBOUND_SESSION, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY message.<br> The recipient is defined as the entity
+     * with whom the session is established.
+     * An exception is thrown if the operation fails.
+     * @param aOlmAccountId account instance
+     * @param aTheirIdentityKey the identity key of the recipient
+     * @param aTheirOneTimeKey the one time key of the recipient
+     **/
+    private native void initOutboundSessionJni(long aOlmAccountId, byte[] aTheirIdentityKey, byte[] aTheirOneTimeKey);
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY message ({@link OlmMessage#MESSAGE_TYPE_PRE_KEY}).<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * @param aAccount the account to associate with this session
+     * @param aPreKeyMsg PRE KEY message
+     * @exception OlmException the failure reason
+     */
+    public void initInboundSession(OlmAccount aAccount, String aPreKeyMsg) throws OlmException {
+        if ((null == aAccount) || TextUtils.isEmpty(aPreKeyMsg)){
+            Log.e(LOG_TAG, "## initInboundSession(): invalid input parameters");
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION, "invalid input parameters");
+        } else {
+            try {
+                initInboundSessionJni(aAccount.getOlmAccountId(), aPreKeyMsg.getBytes("UTF-8"));
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## initInboundSession(): " + e.getMessage());
+                throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY message.<br>
+     * An exception is thrown if the operation fails.
+     * @param aOlmAccountId account instance
+     * @param aOneTimeKeyMsg PRE_KEY message
+     */
+    private native void initInboundSessionJni(long aOlmAccountId, byte[] aOneTimeKeyMsg);
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY({@link OlmMessage#MESSAGE_TYPE_PRE_KEY}) message based on the sender identity key.<br>
+     * Public API for {@link #initInboundSessionFromIdKeyJni(long, byte[], byte[])}.
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * This method must only be called the first time a pre-key message is received from an inbound session.
+     * @param aAccount the account to associate with this session
+     * @param aTheirIdentityKey the sender identity key
+     * @param aPreKeyMsg PRE KEY message
+     * @exception OlmException the failure reason
+     */
+    public void initInboundSessionFrom(OlmAccount aAccount, String aTheirIdentityKey, String aPreKeyMsg) throws OlmException {
+        if ( (null==aAccount) || TextUtils.isEmpty(aPreKeyMsg)){
+            Log.e(LOG_TAG, "## initInboundSessionFrom(): invalid input parameters");
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION_FROM, "invalid input parameters");
+        } else {
+            try {
+                initInboundSessionFromIdKeyJni(aAccount.getOlmAccountId(), aTheirIdentityKey.getBytes("UTF-8"), aPreKeyMsg.getBytes("UTF-8"));
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## initInboundSessionFrom(): " + e.getMessage());
+                throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION_FROM, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY message based on the recipient identity key.<br>
+     * An exception is thrown if the operation fails.
+     * @param aOlmAccountId account instance
+     * @param aTheirIdentityKey the identity key of the recipient
+     * @param aOneTimeKeyMsg encrypted message
+     */
+    private native void initInboundSessionFromIdKeyJni(long aOlmAccountId, byte[] aTheirIdentityKey, byte[] aOneTimeKeyMsg);
+
+    /**
+     * Get the session identifier.<br> Will be the same for both ends of the
+     * conversation. The session identifier is returned as a String object.
+     * Session Id sample: "session_id":"M4fOVwD6AABrkTKl"
+     * Public API for {@link #getSessionIdentifierJni()}.
+     * @return the session ID
+     * @exception OlmException the failure reason
+     */
+    public String sessionIdentifier() throws OlmException {
+        try {
+            byte[] buffer = getSessionIdentifierJni();
+
+            if (null != buffer) {
+                return new String(buffer, "UTF-8");
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## sessionIdentifier(): " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_SESSION_IDENTIFIER, e.getMessage());
+        }
+
+        return null;
+    }
+
+    /**
+     * Get the session identifier for this session.
+     * An exception is thrown if the operation fails.
+     * @return the session identifier
+     */
+    private native byte[] getSessionIdentifierJni();
+
+    /**
+     * Checks if the PRE_KEY({@link OlmMessage#MESSAGE_TYPE_PRE_KEY}) message is for this in-bound session.<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * Public API for {@link #matchesInboundSessionJni(byte[])}.
+     * @param aOneTimeKeyMsg PRE KEY message
+     * @return true if the one time key matches.
+     */
+    public boolean matchesInboundSession(String aOneTimeKeyMsg) {
+        boolean retCode = false;
+
+        try {
+            retCode = matchesInboundSessionJni(aOneTimeKeyMsg.getBytes("UTF-8"));
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## matchesInboundSession(): failed " + e.getMessage());
+        }
+
+        return retCode;
+    }
+
+    /**
+     * Checks if the PRE_KEY message is for this in-bound session.<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * An exception is thrown if the operation fails.
+     * @param aOneTimeKeyMsg PRE KEY message
+     * @return true if the PRE_KEY message matches
+     */
+    private native boolean matchesInboundSessionJni(byte[] aOneTimeKeyMsg);
+
+    /**
+     * Checks if the PRE_KEY({@link OlmMessage#MESSAGE_TYPE_PRE_KEY}) message is for this in-bound session based on the sender identity key.<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * Public API for {@link #matchesInboundSessionJni(byte[])}.
+     * @param aTheirIdentityKey the sender identity key
+     * @param aOneTimeKeyMsg PRE KEY message
+     * @return this if operation succeed, null otherwise
+     */
+    public boolean matchesInboundSessionFrom(String aTheirIdentityKey, String aOneTimeKeyMsg) {
+        boolean retCode = false;
+
+        try {
+            retCode = matchesInboundSessionFromIdKeyJni(aTheirIdentityKey.getBytes("UTF-8"), aOneTimeKeyMsg.getBytes("UTF-8"));
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## matchesInboundSessionFrom(): failed " + e.getMessage());
+        }
+
+        return retCode;
+    }
+
+    /**
+     * Checks if the PRE_KEY message is for this in-bound session based on the sender identity key.<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * An exception is thrown if the operation fails.
+     * @param aTheirIdentityKey the identity key of the sender
+     * @param aOneTimeKeyMsg PRE KEY message
+     * @return true if the PRE_KEY message matches.
+     */
+    private native boolean matchesInboundSessionFromIdKeyJni(byte[] aTheirIdentityKey, byte[] aOneTimeKeyMsg);
+
+    /**
+     * Encrypt a message using the session.<br>
+     * The encrypted message is returned in a OlmMessage object.
+     * Public API for {@link #encryptMessageJni(byte[], OlmMessage)}.
+     * @param aClearMsg message to encrypted
+     * @return the encrypted message
+     * @exception OlmException the failure reason
+     */
+    public OlmMessage encryptMessage(String aClearMsg) throws OlmException {
+        if (null == aClearMsg) {
+            return null;
+        }
+
+        OlmMessage encryptedMsgRetValue = new OlmMessage();
+
+        try {
+            byte[] encryptedMessageBuffer = encryptMessageJni(aClearMsg.getBytes("UTF-8"), encryptedMsgRetValue);
+
+            if (null != encryptedMessageBuffer) {
+                encryptedMsgRetValue.mCipherText = new String(encryptedMessageBuffer, "UTF-8");
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## encryptMessage(): failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_ENCRYPT_MESSAGE, e.getMessage());
+        }
+
+        return encryptedMsgRetValue;
+    }
+
+    /**
+     * Encrypt a message using the session.<br>
+     * An exception is thrown if the operation fails.
+     * @param aClearMsg clear text message
+     * @param aEncryptedMsg ciphered message
+     * @return the encrypted message
+     */
+    private native byte[] encryptMessageJni(byte[] aClearMsg, OlmMessage aEncryptedMsg);
+
+    /**
+     * Decrypt a message using the session.<br>
+     * The encrypted message is given as a OlmMessage object.
+     * @param aEncryptedMsg message to decrypt
+     * @return the decrypted message
+     * @exception OlmException the failure reason
+     */
+    public String decryptMessage(OlmMessage aEncryptedMsg) throws OlmException {
+        if (null == aEncryptedMsg) {
+            return null;
+        }
+
+        try {
+            return new String(decryptMessageJni(aEncryptedMsg), "UTF-8");
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## decryptMessage(): failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_DECRYPT_MESSAGE, e.getMessage());
+        }
+    }
+    /**
+     * Decrypt a message using the session.<br>
+     * An exception is thrown if the operation fails.
+     * @param aEncryptedMsg message to decrypt
+     * @return the decrypted message
+     */
+    private native byte[] decryptMessageJni(OlmMessage aEncryptedMsg);
+
+    //==============================================================================================================
+    // Serialization management
+    //==============================================================================================================
+
+    /**
+     * Kick off the serialization mechanism.
+     * @param aOutStream output stream for serializing
+     * @throws IOException exception
+     */
+    private void writeObject(ObjectOutputStream aOutStream) throws IOException {
+        serialize(aOutStream);
+    }
+
+    /**
+     * Kick off the deserialization mechanism.
+     * @param aInStream input stream
+     * @throws IOException exception
+     * @throws ClassNotFoundException exception
+     */
+    private void readObject(ObjectInputStream aInStream) throws Exception {
+        deserialize(aInStream);
+    }
+
+    /**
+     * Return a session as a bytes buffer.<br>
+     * The account is serialized and encrypted with aKey.
+     * In case of failure, an error human readable
+     * description is provide in aErrorMsg.
+     * @param aKey encryption key
+     * @param aErrorMsg error message description
+     * @return session as a bytes buffer
+     */
+    @Override
+    protected byte[] serialize(byte[] aKey, StringBuffer aErrorMsg) {
+        byte[] pickleRetValue = null;
+
+        // sanity check
+        if(null == aErrorMsg) {
+            Log.e(LOG_TAG,"## serializeDataWithKey(): invalid parameter - aErrorMsg=null");
+        } else if (null == aKey) {
+            aErrorMsg.append("Invalid input parameters in serializeDataWithKey()");
+        } else {
+            aErrorMsg.setLength(0);
+            try {
+                pickleRetValue = serializeJni(aKey);
+            } catch (Exception e) {
+                Log.e(LOG_TAG,"## serializeDataWithKey(): failed " + e.getMessage());
+                aErrorMsg.append(e.getMessage());
+            }
+        }
+
+        return pickleRetValue;
+    }
+
+    /**
+     * Serialize and encrypt session instance.<br>
+     * An exception is thrown if the operation fails.
+     * @param aKeyBuffer key used to encrypt the serialized account data
+     * @return the serialised account as bytes buffer.
+     **/
+    private native byte[] serializeJni(byte[] aKeyBuffer);
+
+    /**
+     * Loads an account from a pickled base64 string.<br>
+     * See {@link #serialize(byte[], StringBuffer)}
+     * @param aSerializedData pickled account in a base64 string format
+     * @param aKey key used to encrypted
+     */
+    @Override
+    protected void deserialize(byte[] aSerializedData, byte[] aKey) throws Exception {
+        String errorMsg = null;
+
+        try {
+            if ((null == aSerializedData) || (null == aKey)) {
+                Log.e(LOG_TAG, "## deserialize(): invalid input parameters");
+                errorMsg = "invalid input parameters";
+            } else {
+                mNativeId = deserializeJni(aSerializedData, aKey);
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## deserialize() failed " + e.getMessage());
+            errorMsg = e.getMessage();
+        }
+
+        if (!TextUtils.isEmpty(errorMsg)) {
+            releaseSession();
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_DESERIALIZATION, errorMsg);
+        }
+    }
+    /**
+     * Allocate a new session and initialize it with the serialisation data.<br>
+     * An exception is thrown if the operation fails.
+     * @param aSerializedData the session serialisation buffer
+     * @param aKey the key used to encrypt the serialized account data
+     * @return the deserialized session
+     **/
+    private native long deserializeJni(byte[] aSerializedData, byte[] aKey);
+}
+

android/olm-sdk/src/main/java/org/matrix/olm/OlmUtility.java

+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 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.text.TextUtils;
+import android.util.Log;
+
+import org.json.JSONObject;
+
+import java.security.SecureRandom;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+/**
+ * Olm SDK helper class.
+ */
+public class OlmUtility {
+    private static final String LOG_TAG = "OlmUtility";
+
+    public static final int RANDOM_KEY_SIZE = 32;
+
+    /** Instance Id returned by JNI.
+     * This value uniquely identifies this utility instance.
+     **/
+    private long mNativeId;
+
+    public OlmUtility() throws OlmException  {
+        initUtility();
+    }
+
+    /**
+     * Create a native utility instance.
+     * To be called before any other API call.
+     * @exception OlmException the exception
+     */
+    private void initUtility() throws OlmException {
+        try {
+            mNativeId = createUtilityJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_UTILITY_CREATION, e.getMessage());
+        }
+    }
+
+    private native long createUtilityJni();
+
+    /**
+     * Release native instance.<br>
+     * Public API for {@link #releaseUtilityJni()}.
+     */
+    public void releaseUtility() {
+        if (0 != mNativeId) {
+            releaseUtilityJni();
+        }
+        mNativeId = 0;
+    }
+    private native void releaseUtilityJni();
+
+    /**
+     * Verify an ed25519 signature.<br>
+     * An exception is thrown if the operation fails.
+     * @param aSignature the base64-encoded message signature to be checked.
+     * @param aFingerprintKey the ed25519 key (fingerprint key)
+     * @param aMessage the signed message
+     * @exception OlmException the failure reason
+     */
+    public void verifyEd25519Signature(String aSignature, String aFingerprintKey, String aMessage) throws OlmException {
+        String errorMessage;
+
+        try {
+            if (TextUtils.isEmpty(aSignature) || TextUtils.isEmpty(aFingerprintKey) || TextUtils.isEmpty(aMessage)) {
+                Log.e(LOG_TAG, "## verifyEd25519Signature(): invalid input parameters");
+                errorMessage = "JAVA sanity check failure - invalid input parameters";
+            } else {
+                errorMessage =  verifyEd25519SignatureJni(aSignature.getBytes("UTF-8"), aFingerprintKey.getBytes("UTF-8"), aMessage.getBytes("UTF-8"));
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## verifyEd25519Signature(): failed " + e.getMessage());
+            errorMessage = e.getMessage();
+        }
+
+        if (!TextUtils.isEmpty(errorMessage)) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_UTILITY_VERIFY_SIGNATURE, errorMessage);
+        }
+    }
+
+    /**
+     * Verify an ed25519 signature.
+     * Return a human readable error message in case of verification failure.
+     * @param aSignature the base64-encoded message signature to be checked.
+     * @param aFingerprintKey the ed25519 key
+     * @param aMessage the signed message
+     * @return null if validation succeed, the error message string if operation failed
+     */
+    private native String verifyEd25519SignatureJni(byte[] aSignature, byte[] aFingerprintKey, byte[] aMessage);
+
+    /**
+     * Compute the hash(SHA-256) value of the string given in parameter(aMessageToHash).<br>
+     * The hash value is the returned by the method.
+     * @param aMessageToHash message to be hashed
+     * @return hash value if operation succeed, null otherwise
+     */
+     public String sha256(String aMessageToHash) {
+         String hashRetValue = null;
+
+         if (null != aMessageToHash) {
+             try {
+                 hashRetValue = new String(sha256Jni(aMessageToHash.getBytes("UTF-8")), "UTF-8");
+             } catch (Exception e) {
+                 Log.e(LOG_TAG, "## sha256(): failed " + e.getMessage());
+             }
+         }
+
+        return hashRetValue;
+    }
+
+    /**
+     * Compute the digest (SHA 256) for the message passed in parameter.<br>
+     * The digest value is the function return value.
+     * An exception is thrown if the operation fails.
+     * @param aMessage the message
+     * @return digest of the message.
+     **/
+    private native byte[] sha256Jni(byte[] aMessage);
+
+    /**
+     * Helper method to compute a string based on random integers.
+     * @return bytes buffer containing randoms integer values
+     */
+    public static byte[] getRandomKey() {
+        SecureRandom secureRandom = new SecureRandom();
+        byte[] buffer = new byte[RANDOM_KEY_SIZE];
+        secureRandom.nextBytes(buffer);
+
+        // the key is saved as string
+        // so avoid the UTF8 marker bytes
+        for(int i = 0; i < RANDOM_KEY_SIZE; i++) {
+            buffer[i] = (byte)(buffer[i] & 0x7F);
+        }
+        return buffer;
+    }
+
+    /**
+     * Return true the object resources have been released.<br>
+     * @return true the object resources have been released
+     */
+    public boolean isReleased() {
+        return (0 == mNativeId);
+    }
+
+    /**
+     * Build a string-string dictionary from a jsonObject.<br>
+     * @param jsonObject the object to parse
+     * @return the map
+     */
+    public static Map<String, String> toStringMap(JSONObject jsonObject) {
+        if (null != jsonObject) {
+            HashMap<String, String> map = new HashMap<>();
+            Iterator<String> keysItr = jsonObject.keys();
+            while(keysItr.hasNext()) {
+                String key = keysItr.next();
+                try {
+                    Object value = jsonObject.get(key);
+
+                    if (value instanceof String) {
+                        map.put(key, (String) value);
+                    } else {
+                        Log.e(LOG_TAG, "## toStringMap(): unexpected type " + value.getClass());
+                    }
+                } catch (Exception e) {
+                    Log.e(LOG_TAG, "## toStringMap(): failed " + e.getMessage());
+                }
+            }
+
+            return map;
+        }
+
+        return null;
+    }
+
+    /**
+     * Build a string-string dictionary of string dictionary from a jsonObject.<br>
+     * @param jsonObject the object to parse
+     * @return the map
+     */
+    public static Map<String, Map<String, String>> toStringMapMap(JSONObject jsonObject) {
+        if (null != jsonObject) {
+            HashMap<String, Map<String, String>> map = new HashMap<>();
+
+            Iterator<String> keysItr = jsonObject.keys();
+            while(keysItr.hasNext()) {
+                String key = keysItr.next();
+                try {
+                    Object value = jsonObject.get(key);
+
+                    if (value instanceof JSONObject) {
+                        map.put(key, toStringMap((JSONObject) value));
+                    } else {
+                        Log.e(LOG_TAG, "## toStringMapMap(): unexpected type " + value.getClass());
+                    }
+                } catch (Exception e) {
+                    Log.e(LOG_TAG, "## toStringMapMap(): failed " + e.getMessage());
+                }
+            }
+
+            return map;
+        }
+
+        return null;
+    }
+}
+

android/olm-sdk/src/main/jni/Android.mk

+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := olm
+MAJOR := 2
+MINOR := 0
+PATCH := 0
+OLM_VERSION := $(MAJOR).$(MINOR).$(PATCH)
+SRC_ROOT_DIR := ../../../../..
+
+$(info LOCAL_PATH=$(LOCAL_PATH))
+$(info SRC_ROOT_DIR=$(SRC_ROOT_DIR))
+$(info OLM_VERSION=$(OLM_VERSION))
+
+LOCAL_CPPFLAGS+= -std=c++11 -Wall
+LOCAL_CONLYFLAGS+= -std=c99
+LOCAL_CFLAGS+= -DOLMLIB_VERSION_MAJOR=$(MAJOR) \
+-DOLMLIB_VERSION_MINOR=$(MINOR) \
+-DOLMLIB_VERSION_PATCH=$(PATCH)
+
+#LOCAL_CFLAGS+= -DNDK_DEBUG
+
+LOCAL_C_INCLUDES+= $(LOCAL_PATH)/$(SRC_ROOT_DIR)/include/ \
+$(LOCAL_PATH)/$(SRC_ROOT_DIR)/lib
+
+$(info LOCAL_C_INCLUDES=$(LOCAL_C_INCLUDES))
+
+LOCAL_SRC_FILES := $(SRC_ROOT_DIR)/src/account.cpp \
+$(SRC_ROOT_DIR)/src/base64.cpp \
+$(SRC_ROOT_DIR)/src/cipher.cpp \
+$(SRC_ROOT_DIR)/src/crypto.cpp \
+$(SRC_ROOT_DIR)/src/memory.cpp \
+$(SRC_ROOT_DIR)/src/message.cpp \
+$(SRC_ROOT_DIR)/src/olm.cpp \
+$(SRC_ROOT_DIR)/src/pickle.cpp \
+$(SRC_ROOT_DIR)/src/ratchet.cpp \
+$(SRC_ROOT_DIR)/src/session.cpp \
+$(SRC_ROOT_DIR)/src/utility.cpp \
+$(SRC_ROOT_DIR)/src/ed25519.c \
+$(SRC_ROOT_DIR)/src/error.c \
+$(SRC_ROOT_DIR)/src/inbound_group_session.c \
+$(SRC_ROOT_DIR)/src/megolm.c \
+$(SRC_ROOT_DIR)/src/outbound_group_session.c \
+$(SRC_ROOT_DIR)/src/pickle_encoding.c \
+$(SRC_ROOT_DIR)/lib/crypto-algorithms/sha256.c \
+$(SRC_ROOT_DIR)/lib/crypto-algorithms/aes.c \
+$(SRC_ROOT_DIR)/lib/curve25519-donna/curve25519-donna.c \
+olm_account.cpp \
+olm_session.cpp \
+olm_jni_helper.cpp \
+olm_inbound_group_session.cpp \
+olm_outbound_group_session.cpp \
+olm_utility.cpp \
+olm_manager.cpp
+
+LOCAL_LDLIBS := -llog
+
+include $(BUILD_SHARED_LIBRARY)
+

android/olm-sdk/src/main/jni/Application.mk

+APP_PLATFORM := android-16
+APP_ABI := arm64-v8a armeabi-v7a armeabi x86_64  x86
+APP_STL := gnustl_static
\ No newline at end of file

android/olm-sdk/src/main/jni/olm_account.h

+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 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.
+ */
+
+#ifndef _OMLACCOUNT_H
+#define _OMLACCOUNT_H
+
+#include "olm_jni.h"
+#include "olm/olm.h"
+
+#define OLM_ACCOUNT_FUNC_DEF(func_name) FUNC_DEF(OlmAccount,func_name)
+#define OLM_MANAGER_FUNC_DEF(func_name) FUNC_DEF(OlmManager,func_name)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// account creation/destruction
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(releaseAccountJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(createNewAccountJni)(JNIEnv *env, jobject thiz);
+
+// identity keys
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(identityKeysJni)(JNIEnv *env, jobject thiz);
+
+// one time keys
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(oneTimeKeysJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(maxOneTimeKeysJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(generateOneTimeKeysJni)(JNIEnv *env, jobject thiz, jint aNumberOfKeys);
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(removeOneTimeKeysJni)(JNIEnv *env, jobject thiz, jlong aNativeOlmSessionId);
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(markOneTimeKeysAsPublishedJni)(JNIEnv *env, jobject thiz);
+
+// signing
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(signMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aMessage);
+
+// serialization
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKeyBuffer);
+JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedDataBuffer, jbyteArray aKeyBuffer);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

android/olm-sdk/src/main/jni/olm_inbound_group_session.h

+/*
+ * 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.
+ */
+
+#ifndef _OMLINBOUND_GROUP_SESSION_H
+#define _OMLINBOUND_GROUP_SESSION_H
+
+#include "olm_jni.h"
+#include "olm/olm.h"
+#include "olm/inbound_group_session.h"
+
+#define OLM_INBOUND_GROUP_SESSION_FUNC_DEF(func_name) FUNC_DEF(OlmInboundGroupSession,func_name)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// session creation/destruction
+JNIEXPORT void OLM_INBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz, jbyteArray aSessionKeyBuffer);
+
+JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(sessionIdentifierJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aEncryptedMsg, jobject aDecryptIndex);
+
+// serialization
+JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKey);
+JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedData, jbyteArray aKey);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

android/olm-sdk/src/main/jni/olm_jni.h

+/*
+ * 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.
+ */
+
+#ifndef _OMLJNI_H
+#define _OMLJNI_H
+
+#include <cstdlib>
+#include <cstdio>
+#include <string>
+#include <sstream>
+#include <jni.h>
+#include <android/log.h>
+
+
+#define TAG "OlmJniNative"
+
+/* logging macros */
+//#define ENABLE_JNI_LOG
+
+#ifdef NDK_DEBUG
+    #warning NDK_DEBUG is defined!
+#endif
+
+#ifdef ENABLE_JNI_LOG
+    #warning ENABLE_JNI_LOG is defined!
+#endif
+
+#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, TAG, __VA_ARGS__)
+
+#ifdef ENABLE_JNI_LOG
+    #define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, TAG, __VA_ARGS__)
+    #define LOGW(...) __android_log_print(ANDROID_LOG_WARN, TAG, __VA_ARGS__)
+#else
+    #define LOGD(...)
+    #define LOGW(...)
+#endif
+
+#define FUNC_DEF(class_name,func_name) JNICALL Java_org_matrix_olm_##class_name##_##func_name
+
+namespace AndroidOlmSdk
+{
+
+}
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// internal helper functions
+bool setRandomInBuffer(JNIEnv *env, uint8_t **aBuffer2Ptr, size_t aRandomSize);
+
+struct OlmSession* getSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+struct OlmAccount* getAccountInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+struct OlmInboundGroupSession* getInboundGroupSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+struct OlmOutboundGroupSession* getOutboundGroupSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+struct OlmUtility* getUtilityInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif

android/olm-sdk/src/main/jni/olm_jni_helper.h

+/*
+ * 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.
+ */
+
+#include "olm_jni.h"
+
+// constant strings
+namespace AndroidOlmSdk
+{
+    static const char *CLASS_OLM_INBOUND_GROUP_SESSION = "org/matrix/olm/OlmInboundGroupSession";
+    static const char *CLASS_OLM_OUTBOUND_GROUP_SESSION = "org/matrix/olm/OlmOutboundGroupSession";
+    static const char *CLASS_OLM_SESSION = "org/matrix/olm/OlmSession";
+    static const char *CLASS_OLM_ACCOUNT = "org/matrix/olm/OlmAccount";
+    static const char *CLASS_OLM_UTILITY = "org/matrix/olm/OlmUtility";
+}

android/olm-sdk/src/main/jni/olm_manager.cpp

+/*
+ * 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.
+ */
+
+#include "olm_manager.h"
+
+using namespace AndroidOlmSdk;
+
+JNIEXPORT jstring OLM_MANAGER_FUNC_DEF(getOlmLibVersionJni)(JNIEnv* env, jobject thiz)
+{
+    uint8_t majorVer=0, minorVer=0, patchVer=0;
+    jstring returnValueStr=0;
+    char buff[150];
+
+    olm_get_library_version(&majorVer, &minorVer, &patchVer);
+    LOGD("## getOlmLibVersionJni(): Major=%d Minor=%d Patch=%d", majorVer, minorVer, patchVer);
+
+    snprintf(buff, sizeof(buff), "%d.%d.%d", majorVer, minorVer, patchVer);
+    returnValueStr = env->NewStringUTF((const char*)buff);
+
+    return returnValueStr;
+}
\ No newline at end of file