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

Android wrappers for olm library

1 files changed, 289 insertions, 0 deletions

diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmOutboundGroupSession.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmOutboundGroupSession.java
new file mode 100644
index 0000000..0481824
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmOutboundGroupSession.java
@@ -0,0 +1,289 @@
+/*
+ * 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);
+
+}