PublicKeyAuthentication.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;

import com.sshtools.ssh.components.SshPrivateKey;
import com.sshtools.ssh.components.SshPublicKey;

/**
 * 
 * <p>
 * Public key based authentication implementation. Public-key authentication
 * uses public-key cryptography to verify the client's identity. To access an
 * account on an SSH server machine, the client proves that it possesses a
 * secret key. A key is authorized if its public component is contained in the
 * accounts authorization file (typically ~/.ssh/authorized_keys).
 * 
 * <p>
 * This class implements a basic publickey <a
 * href="SshAuthentication.html">SshAuthentication</a> that can be passed into
 * the <a href="SshClient.html">SshClient</a> to authenticate. As a username is
 * required to establish a connection it is not required that it be set on the
 * authentication object, however if you wish to change the username you can do
 * so (this may not be allowed by some server implementations).
 * </p>
 * 
 * <p>
 * First you need to load a public/private key pair; a set of utility classes
 * based on the SSHTools public key formats is available in the <a
 * href="../../sshtools/publickey/package-summary.html"
 * >com.sshtools.publickey</a> package.
 * </p>
 * <blockquote>
 * 
 * <pre>
 * FileInputStream in = new FileInputStream("someprivatekey");
 * ByteArrayOutputStream out = new ByteArrayOutputStream();
 * int read;
 * while ((read = in.read()) > -1)
 * 	out.write(read);
 * 
 * in.close();
 * 
 * SshPrivateKeyFile pkf = SshPrivateKeyFileFactory.parse(out.toByteArray());
 * SshKeyPair pair = pkf.toKeyPair("mypassphrase");
 * 
 * PublicKeyAuthentication pk = new PublicKeyAuthentication();
 * pk.setPrivateKey(pair.getPrivateKey());
 * pk.setPublicKey(pair.getPublicKey());
 * 
 * if (ssh.authenticate(pk) == SshAuthentication.COMPLETE)
 * 	System.out.println("Authentication completed");
 * </pre>
 * 
 * </blockquote>
 * 
 * @author Lee David Painter
 */
public class PublicKeyAuthentication implements SshAuthentication {

	String username;
	SshPrivateKey privatekey;
	SshPublicKey publickey;
	boolean authenticating = true;

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.sshtools.ssh.SshAuthentication#setUsername(java.lang.String)
	 */
	public void setUsername(String username) {
		this.username = username;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.sshtools.ssh.SshAuthentication#getUsername()
	 */
	public String getUsername() {
		return username;
	}

	/**
	 * Set the private key for this authentication.
	 * 
	 * @param privatekey
	 */
	public void setPrivateKey(SshPrivateKey privatekey) {
		this.privatekey = privatekey;
	}

	public String getMethod() {
		return "publickey";
	}

	/**
	 * Get the private key for this authentication.
	 * 
	 * @return SshPrivateKey
	 */
	public SshPrivateKey getPrivateKey() {
		return privatekey;
	}

	/**
	 * Set the public key for this authentication.
	 * 
	 * @param publickey
	 */
	public void setPublicKey(SshPublicKey publickey) {
		this.publickey = publickey;
	}

	/**
	 * Get the public key for this authentication.
	 * 
	 * @return SshPublicKey
	 */
	public SshPublicKey getPublicKey() {
		return publickey;
	}

	/**
	 * If <tt>true</tt> the authentication will proceed as normal and the result
	 * will either be a success or failure. If <tt>false</tt> the authentication
	 * result will be either PUBLIC_KEY_ACCEPTABLE or a failure. If the result
	 * returned is PUBLIC_KEY_ACCEPTABLE the authentication can be completed by
	 * setting this flag to <tt>true</tt> and re-authenticating with the
	 * SshClient.
	 * 
	 * @param authenticating
	 */
	public void setAuthenticating(boolean authenticating) {
		this.authenticating = authenticating;
	}

	/**
	 * Is the authentication attempt actually going to perform an authentication
	 * or are we simply just checking the suitability of a public key.
	 * 
	 * @return boolean
	 */
	public boolean isAuthenticating() {
		return authenticating;
	}

}