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

Android wrappers for olm library

1 files changed, 445 insertions, 0 deletions

diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmSession.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmSession.java
new file mode 100644
index 0000000..da2e963
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmSession.java
@@ -0,0 +1,445 @@
+/*
+ * 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);
+}
+