BlockCipherOutputStream.java

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 * The Original Code is part of dcm4che, an implementation of DICOM(TM) in
 * Java(TM), hosted at https://github.com/gunterze/dcm4che.
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 * The Initial Developer of the Original Code is
 * Agfa Healthcare.
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 * See @authors listed below
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package org.dcm4chee.storage.encrypt;

import java.io.IOException;
import java.io.OutputStream;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.CipherOutputStream;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;

/**
 * @author Steve Kroetsch<stevekroetsch@hotmail.com>
 *
 */
public class BlockCipherOutputStream extends CipherOutputStream {

    public BlockCipherOutputStream(OutputStream out, SecretKey secretKey)
            throws IOException {
        super(out, initCipher(secretKey, out));
    }

    private static Cipher initCipher(SecretKey secretKey, OutputStream out) {
        try {
            Cipher cipher = Cipher.getInstance(secretKey.getAlgorithm()
                    + "/CBC/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            writeIV(cipher, out);
            return cipher;
        } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException
                | IOException e) {
            throw new CipherInitializationException(e);
        }
    }

    private static void writeIV(Cipher cipher, OutputStream out) throws IOException {
        out.write(cipher.getIV());
    }
}