Java tutorial
/* * Copyright (C) 2013 The Android Open Source Project * * 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 com.example.android.vault; import android.os.ParcelFileDescriptor; import android.test.AndroidTestCase; import android.test.MoreAsserts; import android.test.suitebuilder.annotation.MediumTest; import org.json.JSONObject; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.RandomAccessFile; import java.nio.charset.StandardCharsets; import java.security.DigestException; import java.util.Arrays; import java.util.concurrent.CountDownLatch; import java.util.concurrent.TimeUnit; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; /** * Tests for {@link EncryptedDocument}. */ @MediumTest public class EncryptedDocumentTest extends AndroidTestCase { private File mFile; private SecretKey mDataKey = new SecretKeySpec(new byte[] { 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01 }, "AES"); private SecretKey mMacKey = new SecretKeySpec(new byte[] { 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02 }, "AES"); @Override protected void setUp() throws Exception { super.setUp(); mFile = new File(getContext().getFilesDir(), "meow"); } @Override protected void tearDown() throws Exception { super.tearDown(); for (File f : getContext().getFilesDir().listFiles()) { f.delete(); } } public void testEmptyFile() throws Exception { mFile.createNewFile(); final EncryptedDocument doc = new EncryptedDocument(4, mFile, mDataKey, mMacKey); try { doc.readMetadata(); fail("expected metadata to throw"); } catch (IOException expected) { } try { final ParcelFileDescriptor[] pipe = ParcelFileDescriptor.createReliablePipe(); doc.readContent(pipe[1]); fail("expected content to throw"); } catch (IOException expected) { } } public void testNormalMetadataAndContents() throws Exception { final byte[] content = "KITTENS".getBytes(StandardCharsets.UTF_8); testMetadataAndContents(content); } public void testGiantMetadataAndContents() throws Exception { // try with content size of prime number >1MB final byte[] content = new byte[1298047]; Arrays.fill(content, (byte) 0x42); testMetadataAndContents(content); } private void testMetadataAndContents(byte[] content) throws Exception { final EncryptedDocument doc = new EncryptedDocument(4, mFile, mDataKey, mMacKey); final byte[] beforeContent = content; final ParcelFileDescriptor[] beforePipe = ParcelFileDescriptor.createReliablePipe(); new Thread() { @Override public void run() { final FileOutputStream os = new FileOutputStream(beforePipe[1].getFileDescriptor()); try { os.write(beforeContent); beforePipe[1].close(); } catch (IOException e) { throw new RuntimeException(e); } } }.start(); // fully write metadata and content final JSONObject before = new JSONObject(); before.put("meow", "cake"); doc.writeMetadataAndContent(before, beforePipe[0]); // now go back and verify we can read final JSONObject after = doc.readMetadata(); assertEquals("cake", after.getString("meow")); final CountDownLatch latch = new CountDownLatch(1); final ParcelFileDescriptor[] afterPipe = ParcelFileDescriptor.createReliablePipe(); final byte[] afterContent = new byte[beforeContent.length]; new Thread() { @Override public void run() { final FileInputStream is = new FileInputStream(afterPipe[0].getFileDescriptor()); try { int i = 0; while (i < afterContent.length) { int n = is.read(afterContent, i, afterContent.length - i); i += n; } afterPipe[0].close(); latch.countDown(); } catch (IOException e) { throw new RuntimeException(e); } } }.start(); doc.readContent(afterPipe[1]); latch.await(5, TimeUnit.SECONDS); MoreAsserts.assertEquals(beforeContent, afterContent); } public void testNormalMetadataOnly() throws Exception { final EncryptedDocument doc = new EncryptedDocument(4, mFile, mDataKey, mMacKey); // write only metadata final JSONObject before = new JSONObject(); before.put("lol", "wut"); doc.writeMetadataAndContent(before, null); // verify we can read final JSONObject after = doc.readMetadata(); assertEquals("wut", after.getString("lol")); final ParcelFileDescriptor[] pipe = ParcelFileDescriptor.createReliablePipe(); try { doc.readContent(pipe[1]); fail("found document content"); } catch (IOException expected) { } } public void testCopiedFile() throws Exception { final EncryptedDocument doc1 = new EncryptedDocument(1, mFile, mDataKey, mMacKey); final EncryptedDocument doc4 = new EncryptedDocument(4, mFile, mDataKey, mMacKey); // write values for doc1 into file final JSONObject meta1 = new JSONObject(); meta1.put("key1", "value1"); doc1.writeMetadataAndContent(meta1, null); // now try reading as doc4, which should fail try { doc4.readMetadata(); fail("somehow read without checking docid"); } catch (DigestException expected) { } } public void testBitTwiddle() throws Exception { final EncryptedDocument doc = new EncryptedDocument(4, mFile, mDataKey, mMacKey); // write some metadata final JSONObject before = new JSONObject(); before.put("twiddle", "twiddle"); doc.writeMetadataAndContent(before, null); final RandomAccessFile f = new RandomAccessFile(mFile, "rw"); f.seek(f.length() - 4); f.write(0x00); f.close(); try { doc.readMetadata(); fail("somehow passed hmac"); } catch (DigestException expected) { } } public void testErrorAbortsWrite() throws Exception { final EncryptedDocument doc = new EncryptedDocument(4, mFile, mDataKey, mMacKey); // write initial metadata final JSONObject init = new JSONObject(); init.put("color", "red"); doc.writeMetadataAndContent(init, null); // try writing with a pipe that reports failure final byte[] content = "KITTENS".getBytes(StandardCharsets.UTF_8); final ParcelFileDescriptor[] pipe = ParcelFileDescriptor.createReliablePipe(); new Thread() { @Override public void run() { final FileOutputStream os = new FileOutputStream(pipe[1].getFileDescriptor()); try { os.write(content); pipe[1].closeWithError("ZOMG"); } catch (IOException e) { throw new RuntimeException(e); } } }.start(); final JSONObject second = new JSONObject(); second.put("color", "blue"); try { doc.writeMetadataAndContent(second, pipe[0]); fail("somehow wrote without error"); } catch (IOException ignored) { } // verify that original metadata still in place final JSONObject after = doc.readMetadata(); assertEquals("red", after.getString("color")); } }