SshX509DsaPublicKey.java

/**
 * Copyright 2003-2016 SSHTOOLS Limited. All Rights Reserved.
 *
 * For product documentation visit https://www.sshtools.com/
 *
 * This file is part of J2SSH Maverick.
 *
 * J2SSH Maverick is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * J2SSH Maverick is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with J2SSH Maverick.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.sshtools.ssh.components.jce;

import java.io.ByteArrayInputStream;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.interfaces.DSAPublicKey;

import com.sshtools.ssh.SshException;

/**
 * Basic implementation of X509 certificate support.
 * 
 * @author not attributable
 */
public class SshX509DsaPublicKey extends Ssh2DsaPublicKey {

	public static final String X509V3_SIGN_DSA = "x509v3-sign-dss";
	X509Certificate cert;

	public SshX509DsaPublicKey() {
	}

	public SshX509DsaPublicKey(X509Certificate cert) {
		super((DSAPublicKey) cert.getPublicKey());
		this.cert = cert;
	}

	/**
	 * Get the algorithm name for the public key.
	 * 
	 * @return the algorithm name, for example "ssh-dss"
	 * @todo Implement this com.sshtools.ssh.SshPublicKey method
	 */
	public String getAlgorithm() {
		return X509V3_SIGN_DSA;
	}

	/**
	 * Encode the public key into a blob of binary data, the encoded result will
	 * be passed into init to recreate the key.
	 * 
	 * @return an encoded byte array
	 * @throws SshException
	 * @todo Implement this com.sshtools.ssh.SshPublicKey method
	 */
	public byte[] getEncoded() throws SshException {

		try {
			return cert.getEncoded();
		} catch (Throwable ex) {
			throw new SshException("Failed to encoded key data",
					SshException.INTERNAL_ERROR, ex);
		}
	}

	/**
	 * Initialize the public key from a blob of binary data.
	 * 
	 * @param blob
	 *            byte[]
	 * @param start
	 *            int
	 * @param len
	 *            int
	 * @throws SshException
	 * @todo Implement this com.sshtools.ssh.SshPublicKey method
	 */
	public void init(byte[] blob, int start, int len) throws SshException {

		try {

			ByteArrayInputStream is = new ByteArrayInputStream(blob, start, len);

			CertificateFactory cf = JCEProvider
					.getProviderForAlgorithm(JCEAlgorithms.JCE_X509) == null ? CertificateFactory
					.getInstance(JCEAlgorithms.JCE_X509) : CertificateFactory
					.getInstance(JCEAlgorithms.JCE_X509, JCEProvider
							.getProviderForAlgorithm(JCEAlgorithms.JCE_X509));

			this.cert = (X509Certificate) cf.generateCertificate(is);

			if (!(cert.getPublicKey() instanceof DSAPublicKey))
				throw new SshException(
						"Certificate public key is not an DSA public key!",
						SshException.BAD_API_USAGE);

			this.pubkey = (DSAPublicKey) cert.getPublicKey();

		} catch (Throwable ex) {
			throw new SshException(ex.getMessage(), SshException.JCE_ERROR, ex);
		}
	}

	public X509Certificate getCertificate() {
		return cert;
	}

}