de.intarsys.pdf.crypt.StandardAuthenticationHandler Maven / Gradle / Ivy

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/*
 * Copyright (c) 2007, intarsys consulting GmbH
 *
 * 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 intarsys 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 OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package de.intarsys.pdf.crypt;

import de.intarsys.pdf.st.STDocument;
import de.intarsys.tools.authenticate.IPasswordProvider;
import de.intarsys.tools.string.CharacterTools;
import de.intarsys.tools.string.StringTools;

/**
 * This object implements the standard authentication strategy for the
 * {@link StandardSecurityHandler}.
 * 
 * This is extracted to allow for the most flexible authentication in
 * interactive and batch or server environments.
 */
public class StandardAuthenticationHandler implements IAuthenticationHandler {

	private IPasswordProvider passwordProvider;

	private int retries = 3;

	private boolean useDefaultAuthentication = true;

	/**
	 * This {@link IAuthenticationHandler} implements the standard
	 * authentication strategy for the built in security handlers.
	 * 

	 * Applying the default (empty user) authentication can be switched off.
	 * 
	 * Password acquiring can be modified using the {@link PasswordProvider}.
	 * 
	 * @see de.intarsys.pdf.crypt.IAuthenticationHandler#authenticate(de.intarsys.pdf.crypt.ISecurityHandler)
	 */
	public void authenticate(ISecurityHandler securityHandler)
			throws COSSecurityException {
		if (!(securityHandler instanceof StandardSecurityHandler)) {
			throw new COSSecurityException("security handler not supported"); //$NON-NLS-1$
		}
		StandardSecurityHandler standardSecurityHandler = (StandardSecurityHandler) securityHandler;
		if (isUseDefaultAuthentication()) {
			if (standardSecurityHandler.authenticateUser(null)) {
				return;
			}
		}
		STDocument stDocument = securityHandler.stGetDoc();
		char[] password = PasswordProvider.getPassword(stDocument);
		if (password != null) {
			if (!authenticate(standardSecurityHandler, password)) {
				throw new COSSecurityException("wrong password"); //$NON-NLS-1$
			}
		} else {
			IPasswordProvider passwordProvider = PasswordProvider
					.getPasswordProvider(stDocument);
			if (passwordProvider == null) {
				passwordProvider = getPasswordProvider();
			}
			if (passwordProvider == null) {
				throw new COSSecurityException("password missing"); //$NON-NLS-1$
			}
			authenticate(standardSecurityHandler, passwordProvider);
		}
	}

	protected boolean authenticate(
			StandardSecurityHandler standardSecurityHandler, char[] password)
			throws COSSecurityException {
		byte[] bytes = CharacterTools.toByteArray(password);
		if (standardSecurityHandler.authenticateOwner(bytes)) {
			return true;
		}
		if (standardSecurityHandler.authenticateUser(bytes)) {
			return true;
		}
		return false;
	}

	protected void authenticate(
			StandardSecurityHandler standardSecurityHandler,
			IPasswordProvider passwordProvider) throws COSSecurityException {
		char[] password = null;
		try {
			while (true) {
				// query password
				password = passwordProvider.getPassword();
				if (password == null) {
					throw new COSSecurityException("password missing"); //$NON-NLS-1$
				}
				if (authenticate(standardSecurityHandler, password)) {
					return;
				}
				retries--;
				if (getRetries() <= 0) {
					throw new COSSecurityException("wrong password"); //$NON-NLS-1$
				}
			}
		} finally {
			StringTools.clear(password);
		}
	}

	public IPasswordProvider getPasswordProvider() {
		if (passwordProvider == null) {
			return PasswordProvider.get();
		}
		return passwordProvider;
	}

	public int getRetries() {
		return retries;
	}

	public boolean isUseDefaultAuthentication() {
		return useDefaultAuthentication;
	}

	public void setPasswordProvider(IPasswordProvider passwordProvider) {
		this.passwordProvider = passwordProvider;
	}

	public void setRetries(int retries) {
		this.retries = retries;
	}

	public void setUseDefaultAuthentication(boolean useDefaultAuthentication) {
		this.useDefaultAuthentication = useDefaultAuthentication;
	}

}