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package org.apache.cayenne.crypto.transformer.bytes;
import java.security.Key;
/**
* Encryptor that stores authentication code into output.
* HMAC is formed from full header concatenated with unencrypted input.
*
* @since 4.0
*/
class HmacEncryptor extends HmacCreator implements BytesEncryptor {
BytesEncryptor delegate;
HmacEncryptor(BytesEncryptor delegate, Header header, Key key) {
super(header, key);
this.delegate = delegate;
}
@Override
public byte[] encrypt(byte[] input, int outputOffset, byte[] flags) {
byte[] hmac = createHmac(input);
byte[] encrypted = delegate.encrypt(input, outputOffset + hmac.length + 1, flags);
encrypted[outputOffset++] = (byte)hmac.length; // store HMAC length
System.arraycopy(hmac, 0, encrypted, outputOffset, hmac.length);
return encrypted;
}
}