| /* |
| * Copyright (c) 1997, 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 javax.crypto; |
| |
| import java.util.*; |
| |
| import java.security.*; |
| import java.security.Provider.Service; |
| import java.security.spec.*; |
| |
| import sun.security.util.Debug; |
| import sun.security.jca.*; |
| import sun.security.jca.GetInstance.Instance; |
| |
| /** |
| * This class provides the functionality of a key agreement (or key |
| * exchange) protocol. |
| * <p> |
| * The keys involved in establishing a shared secret are created by one of the |
| * key generators ({@code KeyPairGenerator} or |
| * {@code KeyGenerator}), a {@code KeyFactory}, or as a result from |
| * an intermediate phase of the key agreement protocol. |
| * |
| * <p> For each of the correspondents in the key exchange, {@code doPhase} |
| * needs to be called. For example, if this key exchange is with one other |
| * party, {@code doPhase} needs to be called once, with the |
| * {@code lastPhase} flag set to {@code true}. |
| * If this key exchange is |
| * with two other parties, {@code doPhase} needs to be called twice, |
| * the first time setting the {@code lastPhase} flag to |
| * {@code false}, and the second time setting it to {@code true}. |
| * There may be any number of parties involved in a key exchange. |
| * |
| * <p> Every implementation of the Java platform is required to support the |
| * following standard {@code KeyAgreement} algorithm: |
| * <ul> |
| * <li>{@code DiffieHellman}</li> |
| * </ul> |
| * This algorithm is described in the <a href= |
| * "{@docRoot}/../specs/security/standard-names.html#keyagreement-algorithms"> |
| * KeyAgreement section</a> of the |
| * Java Security Standard Algorithm Names Specification. |
| * Consult the release documentation for your implementation to see if any |
| * other algorithms are supported. |
| * |
| * @author Jan Luehe |
| * |
| * @see KeyGenerator |
| * @see SecretKey |
| * @since 1.4 |
| */ |
| |
| public class KeyAgreement { |
| |
| private static final Debug debug = |
| Debug.getInstance("jca", "KeyAgreement"); |
| |
| private static final Debug pdebug = |
| Debug.getInstance("provider", "Provider"); |
| private static final boolean skipDebug = |
| Debug.isOn("engine=") && !Debug.isOn("keyagreement"); |
| |
| // The provider |
| private Provider provider; |
| |
| // The provider implementation (delegate) |
| private KeyAgreementSpi spi; |
| |
| // The name of the key agreement algorithm. |
| private final String algorithm; |
| |
| // next service to try in provider selection |
| // null once provider is selected |
| private Service firstService; |
| |
| // remaining services to try in provider selection |
| // null once provider is selected |
| private Iterator<Service> serviceIterator; |
| |
| private final Object lock; |
| |
| /** |
| * Creates a KeyAgreement object. |
| * |
| * @param keyAgreeSpi the delegate |
| * @param provider the provider |
| * @param algorithm the algorithm |
| */ |
| protected KeyAgreement(KeyAgreementSpi keyAgreeSpi, Provider provider, |
| String algorithm) { |
| this.spi = keyAgreeSpi; |
| this.provider = provider; |
| this.algorithm = algorithm; |
| lock = null; |
| } |
| |
| private KeyAgreement(Service s, Iterator<Service> t, String algorithm) { |
| firstService = s; |
| serviceIterator = t; |
| this.algorithm = algorithm; |
| lock = new Object(); |
| } |
| |
| /** |
| * Returns the algorithm name of this {@code KeyAgreement} object. |
| * |
| * <p>This is the same name that was specified in one of the |
| * {@code getInstance} calls that created this |
| * {@code KeyAgreement} object. |
| * |
| * @return the algorithm name of this {@code KeyAgreement} object. |
| */ |
| public final String getAlgorithm() { |
| return this.algorithm; |
| } |
| |
| /** |
| * Returns a {@code KeyAgreement} object that implements the |
| * specified key agreement algorithm. |
| * |
| * <p> This method traverses the list of registered security Providers, |
| * starting with the most preferred Provider. |
| * A new KeyAgreement object encapsulating the |
| * KeyAgreementSpi implementation from the first |
| * Provider that supports the specified algorithm is returned. |
| * |
| * <p> Note that the list of registered providers may be retrieved via |
| * the {@link Security#getProviders() Security.getProviders()} method. |
| * |
| * @implNote |
| * The JDK Reference Implementation additionally uses the |
| * {@code jdk.security.provider.preferred} |
| * {@link Security#getProperty(String) Security} property to determine |
| * the preferred provider order for the specified algorithm. This |
| * may be different than the order of providers returned by |
| * {@link Security#getProviders() Security.getProviders()}. |
| * |
| * @param algorithm the standard name of the requested key agreement |
| * algorithm. |
| * See the KeyAgreement section in the <a href= |
| * "{@docRoot}/../specs/security/standard-names.html#keyagreement-algorithms"> |
| * Java Security Standard Algorithm Names Specification</a> |
| * for information about standard algorithm names. |
| * |
| * @return the new {@code KeyAgreement} object |
| * |
| * @throws NoSuchAlgorithmException if no {@code Provider} supports a |
| * {@code KeyAgreementSpi} implementation for the |
| * specified algorithm |
| * |
| * @throws NullPointerException if {@code algorithm} is {@code null} |
| * |
| * @see java.security.Provider |
| */ |
| public static final KeyAgreement getInstance(String algorithm) |
| throws NoSuchAlgorithmException { |
| Objects.requireNonNull(algorithm, "null algorithm name"); |
| List<Service> services = |
| GetInstance.getServices("KeyAgreement", algorithm); |
| // make sure there is at least one service from a signed provider |
| Iterator<Service> t = services.iterator(); |
| while (t.hasNext()) { |
| Service s = t.next(); |
| if (JceSecurity.canUseProvider(s.getProvider()) == false) { |
| continue; |
| } |
| return new KeyAgreement(s, t, algorithm); |
| } |
| throw new NoSuchAlgorithmException |
| ("Algorithm " + algorithm + " not available"); |
| } |
| |
| /** |
| * Returns a {@code KeyAgreement} object that implements the |
| * specified key agreement algorithm. |
| * |
| * <p> A new KeyAgreement object encapsulating the |
| * KeyAgreementSpi implementation from the specified provider |
| * is returned. The specified provider must be registered |
| * in the security provider list. |
| * |
| * <p> Note that the list of registered providers may be retrieved via |
| * the {@link Security#getProviders() Security.getProviders()} method. |
| * |
| * @param algorithm the standard name of the requested key agreement |
| * algorithm. |
| * See the KeyAgreement section in the <a href= |
| * "{@docRoot}/../specs/security/standard-names.html#keyagreement-algorithms"> |
| * Java Security Standard Algorithm Names Specification</a> |
| * for information about standard algorithm names. |
| * |
| * @param provider the name of the provider. |
| * |
| * @return the new {@code KeyAgreement} object |
| * |
| * @throws IllegalArgumentException if the {@code provider} |
| * is {@code null} or empty |
| * |
| * @throws NoSuchAlgorithmException if a {@code KeyAgreementSpi} |
| * implementation for the specified algorithm is not |
| * available from the specified provider |
| * |
| * @throws NoSuchProviderException if the specified provider is not |
| * registered in the security provider list |
| * |
| * @throws NullPointerException if {@code algorithm} is {@code null} |
| * |
| * @see java.security.Provider |
| */ |
| public static final KeyAgreement getInstance(String algorithm, |
| String provider) throws NoSuchAlgorithmException, |
| NoSuchProviderException { |
| Objects.requireNonNull(algorithm, "null algorithm name"); |
| Instance instance = JceSecurity.getInstance |
| ("KeyAgreement", KeyAgreementSpi.class, algorithm, provider); |
| return new KeyAgreement((KeyAgreementSpi)instance.impl, |
| instance.provider, algorithm); |
| } |
| |
| /** |
| * Returns a {@code KeyAgreement} object that implements the |
| * specified key agreement algorithm. |
| * |
| * <p> A new KeyAgreement object encapsulating the |
| * KeyAgreementSpi implementation from the specified Provider |
| * object is returned. Note that the specified Provider object |
| * does not have to be registered in the provider list. |
| * |
| * @param algorithm the standard name of the requested key agreement |
| * algorithm. |
| * See the KeyAgreement section in the <a href= |
| * "{@docRoot}/../specs/security/standard-names.html#keyagreement-algorithms"> |
| * Java Security Standard Algorithm Names Specification</a> |
| * for information about standard algorithm names. |
| * |
| * @param provider the provider. |
| * |
| * @return the new {@code KeyAgreement} object |
| * |
| * @throws IllegalArgumentException if the {@code provider} |
| * is {@code null} |
| * |
| * @throws NoSuchAlgorithmException if a {@code KeyAgreementSpi} |
| * implementation for the specified algorithm is not available |
| * from the specified Provider object |
| * |
| * @throws NullPointerException if {@code algorithm} is {@code null} |
| * |
| * @see java.security.Provider |
| */ |
| public static final KeyAgreement getInstance(String algorithm, |
| Provider provider) throws NoSuchAlgorithmException { |
| Objects.requireNonNull(algorithm, "null algorithm name"); |
| Instance instance = JceSecurity.getInstance |
| ("KeyAgreement", KeyAgreementSpi.class, algorithm, provider); |
| return new KeyAgreement((KeyAgreementSpi)instance.impl, |
| instance.provider, algorithm); |
| } |
| |
| // max number of debug warnings to print from chooseFirstProvider() |
| private static int warnCount = 10; |
| |
| /** |
| * Choose the Spi from the first provider available. Used if |
| * delayed provider selection is not possible because init() |
| * is not the first method called. |
| */ |
| void chooseFirstProvider() { |
| if (spi != null) { |
| return; |
| } |
| synchronized (lock) { |
| if (spi != null) { |
| return; |
| } |
| if (debug != null) { |
| int w = --warnCount; |
| if (w >= 0) { |
| debug.println("KeyAgreement.init() not first method " |
| + "called, disabling delayed provider selection"); |
| if (w == 0) { |
| debug.println("Further warnings of this type will " |
| + "be suppressed"); |
| } |
| new Exception("Call trace").printStackTrace(); |
| } |
| } |
| Exception lastException = null; |
| while ((firstService != null) || serviceIterator.hasNext()) { |
| Service s; |
| if (firstService != null) { |
| s = firstService; |
| firstService = null; |
| } else { |
| s = serviceIterator.next(); |
| } |
| if (JceSecurity.canUseProvider(s.getProvider()) == false) { |
| continue; |
| } |
| try { |
| Object obj = s.newInstance(null); |
| if (obj instanceof KeyAgreementSpi == false) { |
| continue; |
| } |
| spi = (KeyAgreementSpi)obj; |
| provider = s.getProvider(); |
| // not needed any more |
| firstService = null; |
| serviceIterator = null; |
| return; |
| } catch (Exception e) { |
| lastException = e; |
| } |
| } |
| ProviderException e = new ProviderException |
| ("Could not construct KeyAgreementSpi instance"); |
| if (lastException != null) { |
| e.initCause(lastException); |
| } |
| throw e; |
| } |
| } |
| |
| private static final int I_NO_PARAMS = 1; |
| private static final int I_PARAMS = 2; |
| |
| private void implInit(KeyAgreementSpi spi, int type, Key key, |
| AlgorithmParameterSpec params, SecureRandom random) |
| throws InvalidKeyException, InvalidAlgorithmParameterException { |
| if (type == I_NO_PARAMS) { |
| spi.engineInit(key, random); |
| } else { // I_PARAMS |
| spi.engineInit(key, params, random); |
| } |
| } |
| |
| private void chooseProvider(int initType, Key key, |
| AlgorithmParameterSpec params, SecureRandom random) |
| throws InvalidKeyException, InvalidAlgorithmParameterException { |
| synchronized (lock) { |
| if (spi != null) { |
| implInit(spi, initType, key, params, random); |
| return; |
| } |
| Exception lastException = null; |
| while ((firstService != null) || serviceIterator.hasNext()) { |
| Service s; |
| if (firstService != null) { |
| s = firstService; |
| firstService = null; |
| } else { |
| s = serviceIterator.next(); |
| } |
| // if provider says it does not support this key, ignore it |
| if (s.supportsParameter(key) == false) { |
| continue; |
| } |
| if (JceSecurity.canUseProvider(s.getProvider()) == false) { |
| continue; |
| } |
| try { |
| KeyAgreementSpi spi = (KeyAgreementSpi)s.newInstance(null); |
| implInit(spi, initType, key, params, random); |
| provider = s.getProvider(); |
| this.spi = spi; |
| firstService = null; |
| serviceIterator = null; |
| return; |
| } catch (Exception e) { |
| // NoSuchAlgorithmException from newInstance() |
| // InvalidKeyException from init() |
| // RuntimeException (ProviderException) from init() |
| if (lastException == null) { |
| lastException = e; |
| } |
| } |
| } |
| // no working provider found, fail |
| if (lastException instanceof InvalidKeyException) { |
| throw (InvalidKeyException)lastException; |
| } |
| if (lastException instanceof InvalidAlgorithmParameterException) { |
| throw (InvalidAlgorithmParameterException)lastException; |
| } |
| if (lastException instanceof RuntimeException) { |
| throw (RuntimeException)lastException; |
| } |
| String kName = (key != null) ? key.getClass().getName() : "(null)"; |
| throw new InvalidKeyException |
| ("No installed provider supports this key: " |
| + kName, lastException); |
| } |
| } |
| |
| /** |
| * Returns the provider of this {@code KeyAgreement} object. |
| * |
| * @return the provider of this {@code KeyAgreement} object |
| */ |
| public final Provider getProvider() { |
| chooseFirstProvider(); |
| return this.provider; |
| } |
| |
| /** |
| * Initializes this key agreement with the given key, which is required to |
| * contain all the algorithm parameters required for this key agreement. |
| * |
| * <p> If this key agreement requires any random bytes, it will get |
| * them using the |
| * {@link java.security.SecureRandom} |
| * implementation of the highest-priority |
| * installed provider as the source of randomness. |
| * (If none of the installed providers supply an implementation of |
| * SecureRandom, a system-provided source of randomness will be used.) |
| * |
| * @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. |
| * |
| * @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. |
| */ |
| public final void init(Key key) throws InvalidKeyException { |
| init(key, JceSecurity.RANDOM); |
| } |
| |
| /** |
| * 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}. |
| * However, if the underlying |
| * algorithm implementation does not require any random bytes, |
| * {@code random} 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. |
| */ |
| public final void init(Key key, SecureRandom random) |
| throws InvalidKeyException { |
| if (spi != null) { |
| spi.engineInit(key, random); |
| } else { |
| try { |
| chooseProvider(I_NO_PARAMS, key, null, random); |
| } catch (InvalidAlgorithmParameterException e) { |
| // should never occur |
| throw new InvalidKeyException(e); |
| } |
| } |
| |
| if (!skipDebug && pdebug != null) { |
| pdebug.println("KeyAgreement." + algorithm + " algorithm from: " + |
| getProviderName()); |
| } |
| } |
| |
| /** |
| * Initializes this key agreement with the given key and set of |
| * algorithm parameters. |
| * |
| * <p> If this key agreement requires any random bytes, it will get |
| * them using the |
| * {@link java.security.SecureRandom} |
| * implementation of the highest-priority |
| * installed provider as the source of randomness. |
| * (If none of the installed providers supply an implementation of |
| * SecureRandom, a system-provided source of randomness will be used.) |
| * |
| * @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 |
| * |
| * @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. |
| */ |
| public final void init(Key key, AlgorithmParameterSpec params) |
| throws InvalidKeyException, InvalidAlgorithmParameterException |
| { |
| init(key, params, JceSecurity.RANDOM); |
| } |
| |
| private String getProviderName() { |
| return (provider == null) ? "(no provider)" : provider.getName(); |
| } |
| |
| /** |
| * 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. |
| */ |
| public final void init(Key key, AlgorithmParameterSpec params, |
| SecureRandom random) |
| throws InvalidKeyException, InvalidAlgorithmParameterException |
| { |
| if (spi != null) { |
| spi.engineInit(key, params, random); |
| } else { |
| chooseProvider(I_PARAMS, key, params, random); |
| } |
| |
| if (!skipDebug && pdebug != null) { |
| pdebug.println("KeyAgreement." + algorithm + " algorithm from: " + |
| getProviderName()); |
| } |
| } |
| |
| /** |
| * 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. |
| */ |
| public final Key doPhase(Key key, boolean lastPhase) |
| throws InvalidKeyException, IllegalStateException |
| { |
| chooseFirstProvider(); |
| return spi.engineDoPhase(key, lastPhase); |
| } |
| |
| /** |
| * Generates the shared secret and returns it in a new buffer. |
| * |
| * <p>This method resets this {@code KeyAgreement} object, so that it |
| * can be reused for further key agreements. Unless this key agreement is |
| * reinitialized with one of the {@code init} 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 |
| */ |
| public final byte[] generateSecret() throws IllegalStateException { |
| chooseFirstProvider(); |
| return spi.engineGenerateSecret(); |
| } |
| |
| /** |
| * Generates the shared secret, and places it into the buffer |
| * {@code sharedSecret}, beginning at {@code offset} inclusive. |
| * |
| * <p>If the {@code sharedSecret} buffer is too small to hold the |
| * result, a {@code ShortBufferException} is thrown. |
| * In this case, this call should be repeated with a larger output buffer. |
| * |
| * <p>This method resets this {@code KeyAgreement} object, so that it |
| * can be reused for further key agreements. Unless this key agreement is |
| * reinitialized with one of the {@code init} 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} where the |
| * shared secret will be stored |
| * |
| * @return the number of bytes placed into {@code sharedSecret} |
| * |
| * @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 |
| */ |
| public final int generateSecret(byte[] sharedSecret, int offset) |
| throws IllegalStateException, ShortBufferException |
| { |
| chooseFirstProvider(); |
| return spi.engineGenerateSecret(sharedSecret, offset); |
| } |
| |
| /** |
| * Creates the shared secret and returns it as a {@code SecretKey} |
| * object of the specified algorithm. |
| * |
| * <p>This method resets this {@code KeyAgreement} object, so that it |
| * can be reused for further key agreements. Unless this key agreement is |
| * reinitialized with one of the {@code init} 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 specified secret-key |
| * algorithm is not available |
| * @exception InvalidKeyException if the shared secret-key material cannot |
| * be used to generate a secret key of the specified algorithm (e.g., |
| * the key material is too short) |
| */ |
| public final SecretKey generateSecret(String algorithm) |
| throws IllegalStateException, NoSuchAlgorithmException, |
| InvalidKeyException |
| { |
| chooseFirstProvider(); |
| return spi.engineGenerateSecret(algorithm); |
| } |
| } |
