| /* |
| * Copyright (c) 1997, 2007, 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 |
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| * questions. |
| */ |
| |
| package javax.crypto; |
| |
| import java.security.*; |
| import java.security.spec.*; |
| |
| /** |
| * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>) |
| * for the <code>KeyAgreement</code> class. |
| * All the abstract methods in this class must be implemented by each |
| * cryptographic service provider who wishes to supply the implementation |
| * of a particular key agreement algorithm. |
| * |
| * <p> The keys involved in establishing a shared secret are created by one |
| * of the |
| * key generators (<code>KeyPairGenerator</code> or |
| * <code>KeyGenerator</code>), a <code>KeyFactory</code>, or as a result from |
| * an intermediate phase of the key agreement protocol |
| * ({@link #engineDoPhase(java.security.Key, boolean) engineDoPhase}). |
| * |
| * <p> For each of the correspondents in the key exchange, |
| * <code>engineDoPhase</code> |
| * needs to be called. For example, if the key exchange is with one other |
| * party, <code>engineDoPhase</code> needs to be called once, with the |
| * <code>lastPhase</code> flag set to <code>true</code>. |
| * If the key exchange is |
| * with two other parties, <code>engineDoPhase</code> needs to be called twice, |
| * the first time setting the <code>lastPhase</code> flag to |
| * <code>false</code>, and the second time setting it to <code>true</code>. |
| * There may be any number of parties involved in a key exchange. |
| * |
| * @author Jan Luehe |
| * |
| * @see KeyGenerator |
| * @see SecretKey |
| * @since 1.4 |
| */ |
| |
| public abstract class KeyAgreementSpi { |
| |
| /** |
| * Initializes this key agreement with the given key and source of |
| * randomness. The given key is required to contain all the algorithm |
| * parameters required for this key agreement. |
| * |
| * <p> If the key agreement algorithm requires random bytes, it gets them |
| * from the given source of randomness, <code>random</code>. |
| * However, if the underlying |
| * algorithm implementation does not require any random bytes, |
| * <code>random</code> is ignored. |
| * |
| * @param key the party's private information. For example, in the case |
| * of the Diffie-Hellman key agreement, this would be the party's own |
| * Diffie-Hellman private key. |
| * @param random the source of randomness |
| * |
| * @exception InvalidKeyException if the given key is |
| * inappropriate for this key agreement, e.g., is of the wrong type or |
| * has an incompatible algorithm type. |
| */ |
| protected abstract void engineInit(Key key, SecureRandom random) |
| throws InvalidKeyException; |
| |
| /** |
| * Initializes this key agreement with the given key, set of |
| * algorithm parameters, and source of randomness. |
| * |
| * @param key the party's private information. For example, in the case |
| * of the Diffie-Hellman key agreement, this would be the party's own |
| * Diffie-Hellman private key. |
| * @param params the key agreement parameters |
| * @param random the source of randomness |
| * |
| * @exception InvalidKeyException if the given key is |
| * inappropriate for this key agreement, e.g., is of the wrong type or |
| * has an incompatible algorithm type. |
| * @exception InvalidAlgorithmParameterException if the given parameters |
| * are inappropriate for this key agreement. |
| */ |
| protected abstract void engineInit(Key key, AlgorithmParameterSpec params, |
| SecureRandom random) |
| throws InvalidKeyException, InvalidAlgorithmParameterException; |
| |
| /** |
| * Executes the next phase of this key agreement with the given |
| * key that was received from one of the other parties involved in this key |
| * agreement. |
| * |
| * @param key the key for this phase. For example, in the case of |
| * Diffie-Hellman between 2 parties, this would be the other party's |
| * Diffie-Hellman public key. |
| * @param lastPhase flag which indicates whether or not this is the last |
| * phase of this key agreement. |
| * |
| * @return the (intermediate) key resulting from this phase, or null if |
| * this phase does not yield a key |
| * |
| * @exception InvalidKeyException if the given key is inappropriate for |
| * this phase. |
| * @exception IllegalStateException if this key agreement has not been |
| * initialized. |
| */ |
| protected abstract Key engineDoPhase(Key key, boolean lastPhase) |
| throws InvalidKeyException, IllegalStateException; |
| |
| /** |
| * Generates the shared secret and returns it in a new buffer. |
| * |
| * <p>This method resets this <code>KeyAgreementSpi</code> object, |
| * so that it |
| * can be reused for further key agreements. Unless this key agreement is |
| * reinitialized with one of the <code>engineInit</code> methods, the same |
| * private information and algorithm parameters will be used for |
| * subsequent key agreements. |
| * |
| * @return the new buffer with the shared secret |
| * |
| * @exception IllegalStateException if this key agreement has not been |
| * completed yet |
| */ |
| protected abstract byte[] engineGenerateSecret() |
| throws IllegalStateException; |
| |
| /** |
| * Generates the shared secret, and places it into the buffer |
| * <code>sharedSecret</code>, beginning at <code>offset</code> inclusive. |
| * |
| * <p>If the <code>sharedSecret</code> buffer is too small to hold the |
| * result, a <code>ShortBufferException</code> is thrown. |
| * In this case, this call should be repeated with a larger output buffer. |
| * |
| * <p>This method resets this <code>KeyAgreementSpi</code> object, |
| * so that it |
| * can be reused for further key agreements. Unless this key agreement is |
| * reinitialized with one of the <code>engineInit</code> methods, the same |
| * private information and algorithm parameters will be used for |
| * subsequent key agreements. |
| * |
| * @param sharedSecret the buffer for the shared secret |
| * @param offset the offset in <code>sharedSecret</code> where the |
| * shared secret will be stored |
| * |
| * @return the number of bytes placed into <code>sharedSecret</code> |
| * |
| * @exception IllegalStateException if this key agreement has not been |
| * completed yet |
| * @exception ShortBufferException if the given output buffer is too small |
| * to hold the secret |
| */ |
| protected abstract int engineGenerateSecret(byte[] sharedSecret, |
| int offset) |
| throws IllegalStateException, ShortBufferException; |
| |
| /** |
| * Creates the shared secret and returns it as a secret key object |
| * of the requested algorithm type. |
| * |
| * <p>This method resets this <code>KeyAgreementSpi</code> object, |
| * so that it |
| * can be reused for further key agreements. Unless this key agreement is |
| * reinitialized with one of the <code>engineInit</code> methods, the same |
| * private information and algorithm parameters will be used for |
| * subsequent key agreements. |
| * |
| * @param algorithm the requested secret key algorithm |
| * |
| * @return the shared secret key |
| * |
| * @exception IllegalStateException if this key agreement has not been |
| * completed yet |
| * @exception NoSuchAlgorithmException if the requested secret key |
| * algorithm is not available |
| * @exception InvalidKeyException if the shared secret key material cannot |
| * be used to generate a secret key of the requested algorithm type (e.g., |
| * the key material is too short) |
| */ |
| protected abstract SecretKey engineGenerateSecret(String algorithm) |
| throws IllegalStateException, NoSuchAlgorithmException, |
| InvalidKeyException; |
| } |