/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
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*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is part of dcm4che, an implementation of DICOM(TM) in
* Java(TM), hosted at https://github.com/gunterze/dcm4che.
*
* The Initial Developer of the Original Code is
* Agfa Healthcare.
* Portions created by the Initial Developer are Copyright (C) 2012-2015
* the Initial Developer. All Rights Reserved.
*
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* See @authors listed below
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/**
* @author Steve Kroetsch<stevekroetsch@hotmail.com>
*
*/
package org.dcm4chee.storage.encrypt;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidParameterSpecException;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
/**
* @author Steve Kroetsch<stevekroetsch@hotmail.com>
*
*/
public class BlockCipherInputStream extends CipherInputStream {
public BlockCipherInputStream(InputStream in, SecretKey secretKey) {
super(in, initCipher(secretKey, in));
}
private static Cipher initCipher(SecretKey secretKey, InputStream in) {
try {
Cipher cipher = Cipher.getInstance(secretKey.getAlgorithm()
+ "/CBC/PKCS5Padding");
byte[] iv = readIV(secretKey, in);
IvParameterSpec ivSpec = new IvParameterSpec(iv);
cipher.init(Cipher.DECRYPT_MODE, secretKey, ivSpec);
return cipher;
} catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException
| InvalidAlgorithmParameterException | InvalidParameterSpecException
| IOException e) {
throw new CipherInitializationException(e);
}
}
private static byte[] readIV(SecretKey secretKey, InputStream in) throws IOException,
InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException,
InvalidParameterSpecException {
byte[] iv = new byte[sizeOfIV(secretKey)];
DataInputStream dis = new DataInputStream(in);
dis.readFully(iv);
return iv;
}
private static int sizeOfIV(SecretKey secretKey) throws NoSuchAlgorithmException,
NoSuchPaddingException, InvalidKeyException, InvalidParameterSpecException {
// Determine size by generating temporary cipher with a random IV
Cipher cipher = Cipher
.getInstance(secretKey.getAlgorithm() + "/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
return cipher.getIV().length;
}
}