001    /* CertPathValidator -- validates certificate paths.
002       Copyright (C) 2003, 2004  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010     
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.security.cert;
040    
041    import gnu.java.security.Engine;
042    
043    import java.lang.reflect.InvocationTargetException;
044    import java.security.AccessController;
045    import java.security.InvalidAlgorithmParameterException;
046    import java.security.NoSuchAlgorithmException;
047    import java.security.NoSuchProviderException;
048    import java.security.PrivilegedAction;
049    import java.security.Provider;
050    import java.security.Security;
051    
052    /**
053     * Generic interface to classes that validate certificate paths.
054     *
055     * <p>Using this class is similar to all the provider-based security
056     * classes; the method of interest, {@link
057     * #validate(java.security.cert.CertPath,java.security.cert.CertPathParameters)},
058     * which takes provider-specific implementations of {@link
059     * CertPathParameters}, and return provider-specific implementations of
060     * {@link CertPathValidatorResult}.
061     *
062     * @since JDK 1.4
063     * @see CertPath
064     */
065    public class CertPathValidator {
066    
067      // Constants and fields.
068      // ------------------------------------------------------------------------
069    
070      /** Service name for CertPathValidator. */
071      private static final String CERT_PATH_VALIDATOR = "CertPathValidator";
072    
073      /** The underlying implementation. */
074      private final CertPathValidatorSpi validatorSpi;
075    
076      /** The provider of this implementation. */
077      private final Provider provider;
078    
079      /** The algorithm's name. */
080      private final String algorithm;
081    
082      // Constructor.
083      // ------------------------------------------------------------------------
084    
085      /**
086       * Creates a new CertPathValidator.
087       *
088       * @param validatorSpi The underlying implementation.
089       * @param provider     The provider of the implementation.
090       * @param algorithm    The algorithm name.
091       */
092      protected CertPathValidator(CertPathValidatorSpi validatorSpi,
093                                  Provider provider, String algorithm)
094      {
095        this.validatorSpi = validatorSpi;
096        this.provider = provider;
097        this.algorithm = algorithm;
098      }
099    
100      // Class methods.
101      // ------------------------------------------------------------------------
102    
103      /**
104       * Returns the default validator type.
105       *
106       * <p>This value may be set at run-time via the security property
107       * "certpathvalidator.type", or the value "PKIX" if this property is
108       * not set.
109       *
110       * @return The default validator type.
111       */
112      public static synchronized String getDefaultType() {
113        String type = (String) AccessController.doPrivileged(
114          new PrivilegedAction()
115            {
116              public Object run()
117              {
118                return Security.getProperty("certpathvalidator.type");
119              }
120            }
121        );
122        if (type == null)
123          type = "PKIX";
124        return type;
125      }
126    
127      /**
128       * Returns an instance of the given validator from the first provider that
129       * implements it.
130       * 
131       * @param algorithm The name of the algorithm to get.
132       * @return The new instance.
133       * @throws NoSuchAlgorithmException If no installed provider implements the
134       *           requested algorithm.
135       * @throws IllegalArgumentException if <code>algorithm</code> is
136       *           <code>null</code> or is an empty string.
137       */
138      public static CertPathValidator getInstance(String algorithm)
139        throws NoSuchAlgorithmException
140      {
141        Provider[] p = Security.getProviders();
142        NoSuchAlgorithmException lastException = null;
143        for (int i = 0; i < p.length; i++)
144          try
145            {
146              return getInstance(algorithm, p[i]);
147            }
148          catch (NoSuchAlgorithmException x)
149            {
150              lastException = x;
151            }
152        if (lastException != null)
153          throw lastException;
154        throw new NoSuchAlgorithmException(algorithm);
155      }
156    
157      /**
158       * Returns an instance of the given validator from the named provider.
159       * 
160       * @param algorithm The name of the algorithm to get.
161       * @param provider The name of the provider from which to get the
162       *          implementation.
163       * @return The new instance.
164       * @throws NoSuchAlgorithmException If the named provider does not implement
165       *           the algorithm.
166       * @throws NoSuchProviderException If no provider named <i>provider</i> is
167       *           installed.
168       * @throws IllegalArgumentException if either <code>algorithm</code> or
169       *           <code>provider</code> is <code>null</code>, or if
170       *           <code>algorithm</code> is an empty string.
171       */
172      public static CertPathValidator getInstance(String algorithm, String provider)
173          throws NoSuchAlgorithmException, NoSuchProviderException
174      {
175        if (provider == null)
176          throw new IllegalArgumentException("provider MUST NOT be null");
177        Provider p = Security.getProvider(provider);
178        if (p == null)
179          throw new NoSuchProviderException(provider);
180        return getInstance(algorithm, p);
181      }
182    
183      /**
184       * Returns an instance of the given validator from the given provider.
185       * 
186       * @param algorithm The name of the algorithm to get.
187       * @param provider The provider from which to get the implementation.
188       * @return The new instance.
189       * @throws NoSuchAlgorithmException If the provider does not implement the
190       *           algorithm.
191       * @throws IllegalArgumentException if either <code>algorithm</code> or
192       *           <code>provider</code> is <code>null</code>, or if
193       *           <code>algorithm</code> is an empty string.
194       */
195      public static CertPathValidator getInstance(String algorithm,
196                                                  Provider provider)
197        throws NoSuchAlgorithmException
198      {
199        StringBuilder sb = new StringBuilder("CertPathValidator for algorithm [")
200            .append(algorithm).append("] from provider[")
201            .append(provider).append("] could not be created");
202        Throwable cause;
203        try
204          {
205            Object spi = Engine.getInstance(CERT_PATH_VALIDATOR, algorithm, provider);
206            return new CertPathValidator((CertPathValidatorSpi) spi, provider, algorithm);
207          }
208        catch (InvocationTargetException x)
209          {
210            cause = x.getCause();
211            if (cause instanceof NoSuchAlgorithmException)
212              throw (NoSuchAlgorithmException) cause;
213            if (cause == null)
214              cause = x;
215          }
216        catch (ClassCastException x)
217          {
218            cause = x;
219          }
220        NoSuchAlgorithmException x = new NoSuchAlgorithmException(sb.toString());
221        x.initCause(cause);
222        throw x;
223      }
224    
225      /**
226       * Return the name of this validator.
227       *
228       * @return This validator's name.
229       */
230      public final String getAlgorithm()
231      {
232        return algorithm;
233      }
234    
235      /**
236       * Return the provider of this implementation.
237       *
238       * @return The provider.
239       */
240      public final Provider getProvider()
241      {
242        return provider;
243      }
244    
245      /**
246       * Attempt to validate a certificate path.
247       *
248       * @param certPath The path to validate.
249       * @param params   The algorithm-specific parameters.
250       * @return The result of this validation attempt.
251       * @throws CertPathValidatorException If the certificate path cannot
252       * be validated.
253       * @throws InvalidAlgorithmParameterException If this implementation
254       * rejects the specified parameters.
255       */
256      public final CertPathValidatorResult validate(CertPath certPath,
257                                                    CertPathParameters params)
258        throws CertPathValidatorException, InvalidAlgorithmParameterException
259      {
260        return validatorSpi.engineValidate(certPath, params);
261      }
262    }