allow empty chunks, so UVF's EOF-chunks can be added

Author: overheadhunter

src/main/java/org/cryptomator/cryptolib/common/EncryptingWritableByteChannel.java

@@ -1,11 +1,3 @@
-/*******************************************************************************
- * Copyright (c) 2016 Sebastian Stenzel and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the accompanying LICENSE.txt.
- *
- * Contributors:
- *     Sebastian Stenzel - initial API and implementation
- *******************************************************************************/
 package org.cryptomator.cryptolib.common;
 
 import org.cryptomator.cryptolib.api.Cryptor;
@@ -66,10 +58,8 @@ private void writeHeaderOnFirstWrite() throws IOException {
 
 	private void encryptAndFlushBuffer() throws IOException {
 		cleartextBuffer.flip();
-		if (cleartextBuffer.hasRemaining()) {
-			ByteBuffer ciphertextBuffer = cryptor.fileContentCryptor().encryptChunk(cleartextBuffer, chunkNumber++, header);
-			delegate.write(ciphertextBuffer);
-		}
+		ByteBuffer ciphertextBuffer = cryptor.fileContentCryptor().encryptChunk(cleartextBuffer, chunkNumber++, header);
+		delegate.write(ciphertextBuffer);
 		cleartextBuffer.clear();
 	}
 

src/main/java/org/cryptomator/cryptolib/v1/FileContentCryptorImpl.java

@@ -65,7 +65,7 @@ public ByteBuffer encryptChunk(ByteBuffer cleartextChunk, long chunkNumber, File
 
 	@Override
 	public void encryptChunk(ByteBuffer cleartextChunk, ByteBuffer ciphertextChunk, long chunkNumber, FileHeader header) {
-		if (cleartextChunk.remaining() <= 0 || cleartextChunk.remaining() > PAYLOAD_SIZE) {
+		if (cleartextChunk.remaining() < 0 || cleartextChunk.remaining() > PAYLOAD_SIZE) {
 			throw new IllegalArgumentException("Invalid cleartext chunk size: " + cleartextChunk.remaining() + ", expected range [1, " + PAYLOAD_SIZE + "]");
 		}
 		if (ciphertextChunk.remaining() < CHUNK_SIZE) {

src/main/java/org/cryptomator/cryptolib/v2/FileContentCryptorImpl.java

@@ -63,7 +63,7 @@ public ByteBuffer encryptChunk(ByteBuffer cleartextChunk, long chunkNumber, File
 
 	@Override
 	public void encryptChunk(ByteBuffer cleartextChunk, ByteBuffer ciphertextChunk, long chunkNumber, FileHeader header) {
-		if (cleartextChunk.remaining() <= 0 || cleartextChunk.remaining() > PAYLOAD_SIZE) {
+		if (cleartextChunk.remaining() < 0 || cleartextChunk.remaining() > PAYLOAD_SIZE) {
 			throw new IllegalArgumentException("Invalid cleartext chunk size: " + cleartextChunk.remaining() + ", expected range [1, " + PAYLOAD_SIZE + "]");
 		}
 		if (ciphertextChunk.remaining() < CHUNK_SIZE) {

src/test/java/org/cryptomator/cryptolib/common/EncryptingWritableByteChannelTest.java

@@ -1,11 +1,3 @@
-/*******************************************************************************
- * Copyright (c) 2016 Sebastian Stenzel and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the accompanying LICENSE.txt.
- *
- * Contributors:
- *     Sebastian Stenzel - initial API and implementation
- *******************************************************************************/
 package org.cryptomator.cryptolib.common;
 
 import org.cryptomator.cryptolib.api.Cryptor;
@@ -49,7 +41,8 @@ public void setup() {
 		Mockito.when(contentCryptor.encryptChunk(Mockito.any(ByteBuffer.class), Mockito.anyLong(), Mockito.any(FileHeader.class))).thenAnswer(invocation -> {
 			ByteBuffer input = invocation.getArgument(0);
 			String inStr = UTF_8.decode(input).toString();
-			return ByteBuffer.wrap(inStr.toUpperCase().getBytes(UTF_8));
+			String outStr = "<" + inStr.toUpperCase() + ">";
+			return UTF_8.encode(outStr);
 		});
 	}
 
@@ -60,7 +53,7 @@ public void testEncryption() throws IOException {
 			ch.write(UTF_8.encode("hello world 2"));
 		}
 		dstFile.flip();
-		Assertions.assertArrayEquals("hhhhhHELLO WORLD 1HELLO WORLD 2".getBytes(), Arrays.copyOfRange(dstFile.array(), 0, dstFile.remaining()));
+		Assertions.assertEquals("hhhhh<HELLO WORL><D 1HELLO W><ORLD 2>", UTF_8.decode(dstFile).toString());
 	}
 
 	@Test
@@ -69,7 +62,7 @@ public void testEncryptionOfEmptyFile() throws IOException {
 			// empty, so write nothing
 		}
 		dstFile.flip();
-		Assertions.assertArrayEquals("hhhhh".getBytes(), Arrays.copyOfRange(dstFile.array(), 0, dstFile.remaining()));
+		Assertions.assertEquals("hhhhh<>", UTF_8.decode(dstFile).toString());
 	}
 
 }