Merge pull request #83 from matrix-org/BillCarsonFr/java_sas

Java binding for SAS

2 files changed, 158 insertions, 0 deletions

diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmException.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmException.java
index 532f318..5b4a85a 100644
--- a/android/olm-sdk/src/main/java/org/matrix/olm/OlmException.java
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmException.java
@@ -76,6 +76,11 @@ public class OlmException extends IOException {
     public static final int EXCEPTION_CODE_PK_SIGNING_INIT_WITH_SEED = 802;
     public static final int EXCEPTION_CODE_PK_SIGNING_SIGN = 803;
 
+    public static final int EXCEPTION_CODE_SAS_CREATION = 900;
+    public static final int EXCEPTION_CODE_SAS_ERROR = 901;
+    public static final int EXCEPTION_CODE_SAS_MISSING_THEIR_PKEY = 902;
+    public static final int EXCEPTION_CODE_SAS_GENERATE_SHORT_CODE = 903;
+
     // exception human readable messages
     public static final String EXCEPTION_MSG_INVALID_PARAMS_DESERIALIZATION = "invalid de-serialized parameters";
 
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmSAS.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmSAS.java
new file mode 100644
index 0000000..4bd1579
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmSAS.java
@@ -0,0 +1,153 @@
+/*
+ * Copyright 2019 New Vector 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.util.Log;
+
+import java.io.UnsupportedEncodingException;
+
+public class OlmSAS {
+
+    private static final String LOG_TAG = OlmSAS.class.getName();
+    /**
+     * Session Id returned by JNI.
+     * This value uniquely identifies the native SAS instance.
+     **/
+    private transient long mNativeId;
+
+    private String theirPublicKey = null;
+
+    public OlmSAS() throws OlmException {
+        try {
+            mNativeId = createNewSASJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_SAS_CREATION, e.getMessage());
+        }
+    }
+
+    /**
+     * Gets the Public Key encoded in Base64 with no padding
+     */
+    public String getPublicKey() throws OlmException {
+        try {
+            byte[] buffer = getPubKeyJni();
+
+            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_SAS_ERROR, e.getMessage());
+        }
+
+        return null;
+    }
+
+    /**
+     * Sets the public key of other user.
+     *
+     * @param otherPkey other user public key (base64 encoded with no padding)
+     * @throws OlmException
+     */
+    public void setTheirPublicKey(String otherPkey) throws OlmException {
+        try {
+            setTheirPubKey(otherPkey.getBytes("UTF-8"));
+        } catch (UnsupportedEncodingException e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_SAS_ERROR, e.getMessage());
+        }
+        this.theirPublicKey = otherPkey;
+    }
+
+
+    /**
+     * Generate bytes to use for the short authentication string.
+     *
+     * @param info       info extra information to mix in when generating the bytes, as
+     *                   per the Matrix spec.
+     * @param byteNumber The size of the short code to generate
+     * @return The generated shortcode
+     * @throws OlmException
+     */
+    public byte[] generateShortCode(String info, int byteNumber) throws OlmException {
+        if (theirPublicKey == null || theirPublicKey.isEmpty()) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_SAS_MISSING_THEIR_PKEY, "call setTheirPublicKey first");
+        }
+        try {
+            return generateShortCodeJni(info.getBytes("UTF-8"), byteNumber);
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## sessionIdentifier(): " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_SAS_GENERATE_SHORT_CODE, e.getMessage());
+        }
+    }
+
+
+    public String calculateMac(String message, String info) throws OlmException {
+        try {
+            byte[] bytes = calculateMacJni(message.getBytes("UTF-8"), info.getBytes("UTF-8"));
+            if (bytes != null) return new String(bytes, "UTF-8");
+        } catch (UnsupportedEncodingException e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_SAS_ERROR, e.getMessage());
+        }
+        return null;
+    }
+
+    public String calculateMacLongKdf(String message, String info) throws OlmException {
+        try {
+            byte[] bytes = calculateMacLongKdfJni(message.getBytes("UTF-8"), info.getBytes("UTF-8"));
+            if (bytes != null) return new String(bytes, "UTF-8");
+        } catch (UnsupportedEncodingException e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_SAS_ERROR, e.getMessage());
+        }
+        return null;
+    }
+
+    /**
+     * Create an OLM session in native side.<br>
+     * Do not forget to call {@link #releaseSASJni()} when JAVA side is done.
+     *
+     * @return native account instance identifier or throw an exception.
+     */
+    private native long createNewSASJni();
+
+    /**
+     * 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 #createNewSASJni()}.
+     */
+    private native void releaseSASJni();
+
+    private native byte[] getPubKeyJni();
+
+    private native void setTheirPubKey(byte[] pubKey);
+
+    private native byte[] generateShortCodeJni(byte[] info, int byteNumber);
+
+    private native byte[] calculateMacJni(byte[] message, byte[] info);
+
+    private native byte[] calculateMacLongKdfJni(byte[] message, byte[] info);
+
+    /**
+     * Release native session and invalid its JAVA reference counter part.<br>
+     * Public API for {@link #releaseSASJni()}.
+     */
+    public void releaseSas() {
+        if (0 != mNativeId) {
+            releaseSASJni();
+        }
+        mNativeId = 0;
+    }
+}