Java tutorial
/** * Copyright 2013 Crypto Workshop Pty Ltd * * Licensed 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.cryptoworkshop.ximix.common.asn1.message; import java.util.ArrayList; import java.util.Enumeration; import java.util.List; import org.bouncycastle.asn1.ASN1EncodableVector; import org.bouncycastle.asn1.ASN1Object; import org.bouncycastle.asn1.ASN1OctetString; import org.bouncycastle.asn1.ASN1Primitive; import org.bouncycastle.asn1.ASN1Sequence; import org.bouncycastle.asn1.DEROctetString; import org.bouncycastle.asn1.DERSequence; import org.bouncycastle.asn1.DERUTF8String; /** * Carrier message for a block of messages to have a decryption process applied to. */ public class DecryptDataMessage extends ASN1Object { private final List<byte[]> messages; private final String keyID; /** * Base constructor. * * @param keyID the ID of the private key to decrypt against. * @param messages a list of messages to be decrypted. */ public DecryptDataMessage(String keyID, List<byte[]> messages) { this.keyID = keyID; this.messages = messages; } private DecryptDataMessage(ASN1Sequence seq) { this.keyID = DERUTF8String.getInstance(seq.getObjectAt(0)).getString(); messages = new ArrayList<>(seq.size()); for (Enumeration en = ASN1Sequence.getInstance(seq.getObjectAt(1)).getObjects(); en.hasMoreElements();) { this.messages.add(ASN1OctetString.getInstance(en.nextElement()).getOctets()); } } public static final DecryptDataMessage getInstance(Object o) { if (o instanceof DecryptDataMessage) { return (DecryptDataMessage) o; } else if (o != null) { return new DecryptDataMessage(ASN1Sequence.getInstance(o)); } return null; } @Override public ASN1Primitive toASN1Primitive() { ASN1EncodableVector v = new ASN1EncodableVector(); ASN1EncodableVector mv = new ASN1EncodableVector(); for (byte[] message : messages) { mv.add(new DEROctetString(message)); } v.add(new DERUTF8String(keyID)); v.add(new DERSequence(mv)); return new DERSequence(v); } public List<byte[]> getMessages() { return messages; } public String getKeyID() { return keyID; } }