JwsSignedPayload.java

/*
 * Copyright © 2025 Indiana University
 * All rights reserved.
 *
 * BSD 3-Clause License
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * - Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 * 
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * 
 * - Neither the name of the copyright holder nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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package iu.crypt;

import java.util.Iterator;

import edu.iu.IuObject;
import edu.iu.IuText;
import edu.iu.client.IuJson;
import edu.iu.crypt.WebSignedPayload;

/**
 * JSON Web Signature (JWS) implementation class.
 */
public class JwsSignedPayload implements WebSignedPayload {
	static {
		IuObject.assertNotOpen(JwsSignedPayload.class);
	}

	private final byte[] payload;
	private final Iterable<Jws> signatures;

	/**
	 * Constructor.
	 * 
	 * @param payload    message payload
	 * @param signatures signatures
	 */
	JwsSignedPayload(byte[] payload, Iterable<Jws> signatures) {
		this.payload = payload;
		this.signatures = signatures;
	}

	@Override
	public byte[] getPayload() {
		return payload;
	}

	@Override
	public Iterable<Jws> getSignatures() {
		return signatures;
	}

	@Override
	public String compact() {
		final Iterator<Jws> signatureIterator = signatures.iterator();
		final Jws signature = signatureIterator.next();
		if (signatureIterator.hasNext())
			throw new IllegalStateException("Must have only one signature to use compact serialization");

		return signature.getSignatureInput(payload) + '.' + IuText.base64Url(signature.getSignature());
	}

	@Override
	public String toString() {
		final var json = IuJson.object();
		IuJson.add(json, "payload", () -> payload, CryptJsonAdapters.B64URL);

		final var signatureIterator = signatures.iterator();
		var signature = signatureIterator.next();
		if (signatureIterator.hasNext()) {
			final var signatures = IuJson.array();
			var first = true;
			do {
				if (first)
					first = false;
				else
					signature = signatureIterator.next();

				final var s = IuJson.object();
				signature.serializeTo(s);
				signatures.add(s);
			} while (signatureIterator.hasNext());
			json.add("signatures", signatures);
		} else
			signature.serializeTo(json);

		return json.build().toString();
	}

}