EncryptDecryptFuzzer.java

/* ====================================================================
   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You 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.apache.poi.fuzz;

import static org.apache.poi.poifs.crypt.Decryptor.DEFAULT_POIFS_ENTRY;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.GeneralSecurityException;
import java.util.Arrays;

import org.apache.commons.io.output.UnsynchronizedByteArrayOutputStream;
import org.apache.poi.EncryptedDocumentException;
import org.apache.poi.poifs.crypt.Decryptor;
import org.apache.poi.poifs.crypt.EncryptionInfo;
import org.apache.poi.poifs.crypt.EncryptionMode;
import org.apache.poi.poifs.crypt.Encryptor;
import org.apache.poi.poifs.filesystem.DocumentInputStream;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.util.HexDump;
import org.apache.poi.util.IOUtils;

import com.code_intelligence.jazzer.api.FuzzedDataProvider;

public class EncryptDecryptFuzzer {
	public static void fuzzerInitialize() {
		POIFuzzer.adjustLimits();
	}

	public static void fuzzerTestOneInput(FuzzedDataProvider data) throws IOException, GeneralSecurityException {
		try {
			EncryptionMode encryptionMode = EncryptionMode.values()[(data.consumeInt(0, EncryptionMode.values().length - 1))];
			String password = data.consumeString(20);
			byte[] testData = data.consumeRemainingAsBytes();

			EncryptionInfo infoEnc = new EncryptionInfo(encryptionMode);
			Encryptor enc = infoEnc.getEncryptor();
			enc.confirmPassword(password);

			byte[] encData;
			byte[] encDocument;
			try (POIFSFileSystem fsEnc = new POIFSFileSystem()) {
				try (OutputStream os = enc.getDataStream(fsEnc)) {
					os.write(testData);
				}

				UnsynchronizedByteArrayOutputStream bos = UnsynchronizedByteArrayOutputStream.builder().get();
				fsEnc.writeFilesystem(bos);

				bos.close();
				encData = bos.toByteArray();

				DocumentInputStream dis = fsEnc.getRoot().createDocumentInputStream(DEFAULT_POIFS_ENTRY);
				/*long _length =*/
				dis.readLong();
				encDocument = IOUtils.toByteArray(dis);
			}

			byte[] actualData;
			try (POIFSFileSystem fsDec = new POIFSFileSystem(new ByteArrayInputStream(encData))) {
				EncryptionInfo infoDec = new EncryptionInfo(fsDec);
				Decryptor dec = infoDec.getDecryptor();
				if (!dec.verifyPassword(password)) {
					throw new IllegalStateException("Could not verify password when decrypting " + password + "\n" +
							HexDump.dump(testData, 0, 0) + " and encrypted \n" +
							HexDump.dump(encDocument, 0, 0) + " full encrypted \n" +
							HexDump.dump(encData, 0, 0));
				}
				InputStream is = dec.getDataStream(fsDec);

				actualData = IOUtils.toByteArray(is);
				is.close();
			}

			// input-data and resulting decrypted data should be equal
			if (!Arrays.equals(testData, actualData)) {
				throw new IllegalStateException("Resulting array was not equal to input-array, "
						+ "having " + testData.length + " bytes, had actual length " + actualData.length + " and expected \n" +
						HexDump.dump(testData, 0, 0) + " and actual \n" +
						HexDump.dump(actualData, 0, 0) + " encrypted \n" +
						HexDump.dump(encDocument, 0, 0) + " full encrypted \n" +
						HexDump.dump(encData, 0, 0));
			}
		} catch (IOException | EncryptedDocumentException e) {
			// expected, e.g. when something is not supported
		}
	}
}