/*
* @(#)CertPathBuilder.java 1.13 06/04/21
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.security.cert;
import java.security.AccessController;
import java.security.InvalidAlgorithmParameterException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.PrivilegedAction;
import java.security.Provider;
import java.security.Security;
import sun.security.util.Debug;
import sun.security.jca.*;
import sun.security.jca.GetInstance.Instance;
/**
* A class for building certification paths (also known as certificate chains).
* <p>
* This class uses a provider-based architecture.
* To create a <code>CertPathBuilder</code>, call
* one of the static <code>getInstance</code> methods, passing in the
* algorithm name of the <code>CertPathBuilder</code> desired and optionally
* the name of the provider desired.
* <p>
* Once a <code>CertPathBuilder</code> object has been created, certification
* paths can be constructed by calling the {@link #build build} method and
* passing it an algorithm-specific set of parameters. If successful, the
* result (including the <code>CertPath</code> that was built) is returned
* in an object that implements the <code>CertPathBuilderResult</code>
* interface.
* <p>
* <b>Concurrent Access</b>
* <p>
* The static methods of this class are guaranteed to be thread-safe.
* Multiple threads may concurrently invoke the static methods defined in
* this class with no ill effects.
* <p>
* However, this is not true for the non-static methods defined by this class.
* Unless otherwise documented by a specific provider, threads that need to
* access a single <code>CertPathBuilder</code> instance concurrently should
* synchronize amongst themselves and provide the necessary locking. Multiple
* threads each manipulating a different <code>CertPathBuilder</code> instance
* need not synchronize.
*
* @see CertPath
*
* @version 1.13 04/21/06
* @since 1.4
* @author Sean Mullan
* @author Yassir Elley
*/
public class CertPathBuilder {
/*
* Constant to lookup in the Security properties file to determine
* the default certpathbuilder type. In the Security properties file,
* the default certpathbuilder type is given as:
* <pre>
* certpathbuilder.type=PKIX
* </pre>
*/
private static final String CPB_TYPE = "certpathbuilder.type";
private static final Debug debug = Debug.getInstance("certpath");
private CertPathBuilderSpi builderSpi;
private Provider provider;
private String algorithm;
/**
* Creates a <code>CertPathBuilder</code> object of the given algorithm,
* and encapsulates the given provider implementation (SPI object) in it.
*
* @param builderSpi the provider implementation
* @param provider the provider
* @param algorithm the algorithm name
*/
protected CertPathBuilder(CertPathBuilderSpi builderSpi, Provider provider,
String algorithm)
{
this.builderSpi = builderSpi;
this.provider = provider;
this.algorithm = algorithm;
}
/**
* Returns a <code>CertPathBuilder</code> object that implements the
* specified algorithm.
*
* <p> This method traverses the list of registered security Providers,
* starting with the most preferred Provider.
* A new CertPathBuilder object encapsulating the
* CertPathBuilderSpi 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.
*
* @param algorithm the name of the requested <code>CertPathBuilder</code>
* algorithm. See Appendix A in the <a href=
* "../../../../technotes/guides/security/certpath/CertPathProgGuide.html#AppA">
* Java Certification Path API Programmer's Guide </a>
* for information about standard algorithm names.
*
* @return a <code>CertPathBuilder</code> object that implements the
* specified algorithm.
*
* @throws NoSuchAlgorithmException if no Provider supports a
* CertPathBuilderSpi implementation for the
* specified algorithm.
*
* @see java.security.Provider
*/
public static CertPathBuilder getInstance(String algorithm)
throws NoSuchAlgorithmException {
Instance instance = GetInstance.getInstance("CertPathBuilder",
CertPathBuilderSpi.class, algorithm);
return new CertPathBuilder((CertPathBuilderSpi)instance.impl,
instance.provider, algorithm);
}
/**
* Returns a <code>CertPathBuilder</code> object that implements the
* specified algorithm.
*
* <p> A new CertPathBuilder object encapsulating the
* CertPathBuilderSpi 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 name of the requested <code>CertPathBuilder</code>
* algorithm. See Appendix A in the <a href=
* "../../../../technotes/guides/security/certpath/CertPathProgGuide.html#AppA">
* Java Certification Path API Programmer's Guide </a>
* for information about standard algorithm names.
*
* @param provider the name of the provider.
*
* @return a <code>CertPathBuilder</code> object that implements the
* specified algorithm.
*
* @throws NoSuchAlgorithmException if a CertPathBuilderSpi
* 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.
*
* @exception IllegalArgumentException if the <code>provider</code> is
* null or empty.
*
* @see java.security.Provider
*/
public static CertPathBuilder getInstance(String algorithm, String provider)
throws NoSuchAlgorithmException, NoSuchProviderException {
Instance instance = GetInstance.getInstance("CertPathBuilder",
CertPathBuilderSpi.class, algorithm, provider);
return new CertPathBuilder((CertPathBuilderSpi)instance.impl,
instance.provider, algorithm);
}
/**
* Returns a <code>CertPathBuilder</code> object that implements the
* specified algorithm.
*
* <p> A new CertPathBuilder object encapsulating the
* CertPathBuilderSpi 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 name of the requested <code>CertPathBuilder</code>
* algorithm. See Appendix A in the <a href=
* "../../../../technotes/guides/security/certpath/CertPathProgGuide.html#AppA">
* Java Certification Path API Programmer's Guide </a>
* for information about standard algorithm names.
*
* @param provider the provider.
*
* @return a <code>CertPathBuilder</code> object that implements the
* specified algorithm.
*
* @exception NoSuchAlgorithmException if a CertPathBuilderSpi
* implementation for the specified algorithm is not available
* from the specified Provider object.
*
* @exception IllegalArgumentException if the <code>provider</code> is
* null.
*
* @see java.security.Provider
*/
public static CertPathBuilder getInstance(String algorithm,
Provider provider) throws NoSuchAlgorithmException {
Instance instance = GetInstance.getInstance("CertPathBuilder",
CertPathBuilderSpi.class, algorithm, provider);
return new CertPathBuilder((CertPathBuilderSpi)instance.impl,
instance.provider, algorithm);
}
/**
* Returns the provider of this <code>CertPathBuilder</code>.
*
* @return the provider of this <code>CertPathBuilder</code>
*/
public final Provider getProvider() {
return this.provider;
}
/**
* Returns the name of the algorithm of this <code>CertPathBuilder</code>.
*
* @return the name of the algorithm of this <code>CertPathBuilder</code>
*/
public final String getAlgorithm() {
return this.algorithm;
}
/**
* Attempts to build a certification path using the specified algorithm
* parameter set.
*
* @param params the algorithm parameters
* @return the result of the build algorithm
* @throws CertPathBuilderException if the builder is unable to construct
* a certification path that satisfies the specified parameters
* @throws InvalidAlgorithmParameterException if the specified parameters
* are inappropriate for this <code>CertPathBuilder</code>
*/
public final CertPathBuilderResult build(CertPathParameters params)
throws CertPathBuilderException, InvalidAlgorithmParameterException
{
return builderSpi.engineBuild(params);
}
/**
* Returns the default <code>CertPathBuilder</code> type as specified in
* the Java security properties file, or the string "PKIX"
* if no such property exists. The Java security properties file is
* located in the file named <JAVA_HOME>/lib/security/java.security.
* <JAVA_HOME> refers to the value of the java.home system property,
* and specifies the directory where the JRE is installed.
*
* <p>The default <code>CertPathBuilder</code> type can be used by
* applications that do not want to use a hard-coded type when calling one
* of the <code>getInstance</code> methods, and want to provide a default
* type in case a user does not specify its own.
*
* <p>The default <code>CertPathBuilder</code> type can be changed by
* setting the value of the "certpathbuilder.type" security property
* (in the Java security properties file) to the desired type.
*
* @return the default <code>CertPathBuilder</code> type as specified
* in the Java security properties file, or the string "PKIX"
* if no such property exists.
*/
public final static String getDefaultType() {
String cpbtype;
cpbtype = (String)AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
return Security.getProperty(CPB_TYPE);
}
});
if (cpbtype == null) {
cpbtype = "PKIX";
}
return cpbtype;
}
}
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