/*
* 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.nifi.security.util.crypto;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import org.apache.nifi.processor.exception.ProcessException;
import org.apache.nifi.security.util.EncryptionMethod;
public abstract class KeyedCipherProvider implements CipherProvider {
static final byte[] IV_DELIMITER = "NiFiIV".getBytes(StandardCharsets.UTF_8);
// This is 16 bytes for AES but can vary for other ciphers
static final int MAX_IV_LIMIT = 16;
/**
* Returns an initialized cipher for the specified algorithm. The IV is provided externally to allow for non-deterministic IVs, as IVs
* deterministically derived from the password are a potential vulnerability and compromise semantic security. See
* <a href="http://crypto.stackexchange.com/a/3970/12569">Ilmari Karonen's answer on Crypto Stack Exchange</a>
*
* @param encryptionMethod the {@link EncryptionMethod}
* @param key the key
* @param iv the IV or nonce
* @param encryptMode true for encrypt, false for decrypt
* @return the initialized cipher
* @throws Exception if there is a problem initializing the cipher
*/
abstract Cipher getCipher(EncryptionMethod encryptionMethod, SecretKey key, byte[] iv, boolean encryptMode) throws Exception;
/**
* Returns an initialized cipher for the specified algorithm. The IV will be generated internally (for encryption). If decryption is requested, it will throw an exception.
*
* @param encryptionMethod the {@link EncryptionMethod}
* @param key the key
* @param encryptMode true for encrypt, false for decrypt
* @return the initialized cipher
* @throws Exception if there is a problem initializing the cipher or if decryption is requested
*/
abstract Cipher getCipher(EncryptionMethod encryptionMethod, SecretKey key, boolean encryptMode) throws Exception;
/**
* Generates a new random IV of the correct length.
*
* @return the IV
*/
abstract byte[] generateIV();
public byte[] readIV(InputStream in) throws IOException, ProcessException {
return CipherUtility.readBytesFromInputStream(in, "IV", MAX_IV_LIMIT, IV_DELIMITER);
}
public void writeIV(byte[] iv, OutputStream out) throws IOException {
CipherUtility.writeBytesToOutputStream(out, iv, "IV", IV_DELIMITER);
}
}