Java tutorial
/* * Copyright (c) 1996, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.security; import java.io.*; import java.util.Date; /** * <p>This is an interface of abstract methods for managing a * variety of identity certificates. * An identity certificate is a guarantee by a principal that * a public key is that of another principal. (A principal represents * an entity such as an individual user, a group, or a corporation.) * * <p>In particular, this interface is intended to be a common * abstraction for constructs that have different formats but * important common uses. For example, different types of * certificates, such as X.509 certificates and PGP certificates, * share general certificate functionality (the need to encode and * decode certificates) and some types of information, such as a * public key, the principal whose key it is, and the guarantor * guaranteeing that the public key is that of the specified * principal. So an implementation of X.509 certificates and an * implementation of PGP certificates can both utilize the Certificate * interface, even though their formats and additional types and * amounts of information stored are different. * * <p><b>Important</b>: This interface is useful for cataloging and * grouping objects sharing certain common uses. It does not have any * semantics of its own. In particular, a Certificate object does not * make any statement as to the <i>validity</i> of the binding. It is * the duty of the application implementing this interface to verify * the certificate and satisfy itself of its validity. * * @author Benjamin Renaud * @since 1.1 * @deprecated This class is deprecated and subject to removal in a future * version of Java SE. It has been replaced by * {@code java.security.cert.Certificate} and related classes. * @see java.security.cert.Certificate */ @Deprecated(since = "1.2", forRemoval = true) public interface Certificate { /** * Returns the guarantor of the certificate, that is, the principal * guaranteeing that the public key associated with this certificate * is that of the principal associated with this certificate. For X.509 * certificates, the guarantor will typically be a Certificate Authority * (such as the United States Postal Service or Verisign, Inc.). * * @return the guarantor which guaranteed the principal-key * binding. */ public abstract Principal getGuarantor(); /** * Returns the principal of the principal-key pair being guaranteed by * the guarantor. * * @return the principal to which this certificate is bound. */ public abstract Principal getPrincipal(); /** * Returns the key of the principal-key pair being guaranteed by * the guarantor. * * @return the public key that this certificate certifies belongs * to a particular principal. */ public abstract PublicKey getPublicKey(); /** * Encodes the certificate to an output stream in a format that can * be decoded by the {@code decode} method. * * @param stream the output stream to which to encode the * certificate. * * @exception KeyException if the certificate is not * properly initialized, or data is missing, etc. * * @exception IOException if a stream exception occurs while * trying to output the encoded certificate to the output stream. * * @see #decode * @see #getFormat */ public abstract void encode(OutputStream stream) throws KeyException, IOException; /** * Decodes a certificate from an input stream. The format should be * that returned by {@code getFormat} and produced by * {@code encode}. * * @param stream the input stream from which to fetch the data * being decoded. * * @exception KeyException if the certificate is not properly initialized, * or data is missing, etc. * * @exception IOException if an exception occurs while trying to input * the encoded certificate from the input stream. * * @see #encode * @see #getFormat */ public abstract void decode(InputStream stream) throws KeyException, IOException; /** * Returns the name of the coding format. This is used as a hint to find * an appropriate parser. It could be "X.509", "PGP", etc. This is * the format produced and understood by the {@code encode} * and {@code decode} methods. * * @return the name of the coding format. */ public abstract String getFormat(); /** * Returns a string that represents the contents of the certificate. * * @param detailed whether or not to give detailed information * about the certificate * * @return a string representing the contents of the certificate */ public String toString(boolean detailed); }