File content encryption and decryption (still without padding, no par…

…tial support)

main/filesystem-crypto/pom.xml

@@ -43,12 +43,6 @@
 			<artifactId>bcprov-jdk15on</artifactId>
 			<version>${bouncycastle.version}</version>
 		</dependency>
-
-		<!-- Guava -->
-		<dependency>
-			<groupId>com.google.guava</groupId>
-			<artifactId>guava</artifactId>
-		</dependency>
 
 		<!-- Commons -->
 		<dependency>

main/filesystem-crypto/src/main/java/org/cryptomator/crypto/engine/FileContentCryptor.java

@@ -8,6 +8,8 @@
  */
 public interface FileContentCryptor {
 
+	public static final ByteBuffer EOF = ByteBuffer.allocate(0);
+
 	/**
 	 * @return The fixed number of bytes of the file header. The header length is implementation-specific.
 	 */

main/filesystem-crypto/src/main/java/org/cryptomator/crypto/engine/FileContentDecryptor.java

@@ -1,15 +1,14 @@
 package org.cryptomator.crypto.engine;
 
+import java.io.Closeable;
 import java.nio.ByteBuffer;
 
 import javax.security.auth.Destroyable;
 
 /**
  * Stateful, thus not thread-safe.
  */
-public interface FileContentDecryptor extends Destroyable {
-
-	public static final ByteBuffer EOF = ByteBuffer.allocate(0);
+public interface FileContentDecryptor extends Destroyable, Closeable {
 
 	/**
 	 * @return Number of bytes of the decrypted file.
@@ -19,7 +18,7 @@ public interface FileContentDecryptor extends Destroyable {
 	/**
 	 * Appends further ciphertext to this decryptor. This method might block until space becomes available. If so, it is interruptable.
 	 * 
-	 * @param cleartext Cleartext data or {@link #EOF} to indicate the end of a ciphertext.
+	 * @param cleartext Cleartext data or {@link FileContentCryptor#EOF} to indicate the end of a ciphertext.
 	 * @see #skipToPosition(long)
 	 */
 	void append(ByteBuffer ciphertext);
@@ -30,7 +29,7 @@ public interface FileContentDecryptor extends Destroyable {
 	 * 
 	 * This method might block if no cleartext is available yet.
 	 * 
-	 * @return Decrypted cleartext or {@link #EOF}.
+	 * @return Decrypted cleartext or {@link FileContentCryptor#EOF}.
 	 */
 	ByteBuffer cleartext() throws InterruptedException;
 
@@ -57,4 +56,9 @@ public interface FileContentDecryptor extends Destroyable {
 	@Override
 	void destroy();
 
+	@Override
+	default void close() {
+		this.destroy();
+	}
+
 }

main/filesystem-crypto/src/main/java/org/cryptomator/crypto/engine/FileContentEncryptor.java

@@ -1,15 +1,14 @@
 package org.cryptomator.crypto.engine;
 
+import java.io.Closeable;
 import java.nio.ByteBuffer;
 
 import javax.security.auth.Destroyable;
 
 /**
  * Stateful, thus not thread-safe.
  */
-public interface FileContentEncryptor extends Destroyable {
-
-	public static final ByteBuffer EOF = ByteBuffer.allocate(0);
+public interface FileContentEncryptor extends Destroyable, Closeable {
 
 	/**
 	 * Creates the encrypted file header. This header might depend on the already encrypted data,
@@ -22,7 +21,7 @@ public interface FileContentEncryptor extends Destroyable {
 	/**
 	 * Appends further cleartext to this encryptor. This method might block until space becomes available.
 	 * 
-	 * @param cleartext Cleartext data or {@link #EOF} to indicate the end of a cleartext.
+	 * @param cleartext Cleartext data or {@link FileContentCryptor#EOF} to indicate the end of a cleartext.
 	 */
 	void append(ByteBuffer cleartext);
 
@@ -32,7 +31,7 @@ public interface FileContentEncryptor extends Destroyable {
 	 * 
 	 * This method might block if no ciphertext is available yet.
 	 * 
-	 * @return Encrypted ciphertext of {@link #EOF}.
+	 * @return Encrypted ciphertext of {@link FileContentCryptor#EOF}.
 	 */
 	ByteBuffer ciphertext() throws InterruptedException;
 
@@ -59,4 +58,9 @@ public interface FileContentEncryptor extends Destroyable {
 	@Override
 	void destroy();
 
+	@Override
+	default void close() {
+		this.destroy();
+	}
+
 }

main/filesystem-crypto/src/main/java/org/cryptomator/crypto/engine/impl/AbstractFileContentProcessor.java

@@ -0,0 +1,60 @@
+package org.cryptomator.crypto.engine.impl;
+
+import java.io.Closeable;
+import java.nio.ByteBuffer;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Future;
+import java.util.concurrent.PriorityBlockingQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.commons.lang3.concurrent.ConcurrentUtils;
+
+abstract class AbstractFileContentProcessor implements Closeable {
+
+	private static final int NUM_WORKERS = Runtime.getRuntime().availableProcessors();
+	private static final int READ_AHEAD = 0;
+
+	private final BlockingQueue<BytesWithSequenceNumber> processedData = new PriorityBlockingQueue<>();
+	private final BlockingQueue<Runnable> workQueue = new ArrayBlockingQueue<>(NUM_WORKERS + READ_AHEAD);
+	private final ExecutorService executorService = new ThreadPoolExecutor(1, NUM_WORKERS, 1, TimeUnit.SECONDS, workQueue);
+	private final AtomicLong jobSequence = new AtomicLong();
+
+	/**
+	 * Enqueues a job for execution. The results of multiple submissions can be polled in FIFO order using {@link #processedData()}.
+	 * 
+	 * @param processingJob A ByteBuffer-generating task.
+	 */
+	protected void submit(Callable<ByteBuffer> processingJob) {
+		Future<ByteBuffer> result = executorService.submit(processingJob);
+		processedData.offer(new BytesWithSequenceNumber(result, jobSequence.getAndIncrement()));
+	}
+
+	/**
+	 * Submits already processed data, that can be polled in FIFO order from {@link #processedData()}.
+	 */
+	protected void submitPreprocessed(ByteBuffer preprocessedData) {
+		Future<ByteBuffer> resolvedFuture = ConcurrentUtils.constantFuture(preprocessedData);
+		processedData.offer(new BytesWithSequenceNumber(resolvedFuture, jobSequence.getAndIncrement()));
+	}
+
+	/**
+	 * Result of previously {@link #submit(Callable) submitted} jobs in the same order as they have been submitted. Blocks if the job didn't finish yet.
+	 * 
+	 * @return Next job result
+	 * @throws InterruptedException If the calling thread was interrupted while waiting for the next result.
+	 */
+	protected ByteBuffer processedData() throws InterruptedException {
+		return processedData.take().get();
+	}
+
+	@Override
+	public void close() {
+		executorService.shutdown();
+	}
+
+}

main/filesystem-crypto/src/main/java/org/cryptomator/crypto/engine/impl/FileContentCryptorImpl.java

@@ -32,11 +32,17 @@ public int getHeaderSize() {
 
 	@Override
 	public FileContentDecryptor createFileContentDecryptor(ByteBuffer header) {
-		throw new UnsupportedOperationException("Method not implemented");
+		if (header.remaining() != getHeaderSize()) {
+			throw new IllegalArgumentException("Invalid header.");
+		}
+		return new FileContentDecryptorImpl(encryptionKey, macKey, header);
 	}
 
 	@Override
 	public FileContentEncryptor createFileContentEncryptor(Optional<ByteBuffer> header) {
+		if (header.isPresent() && header.get().remaining() != getHeaderSize()) {
+			throw new IllegalArgumentException("Invalid header.");
+		}
 		return new FileContentEncryptorImpl(encryptionKey, macKey, randomSource);
 	}