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package sun.security.provider.certpath;

import java.security.InvalidAlgorithmParameterException;
import java.security.cert.Certificate;
import java.security.cert.CRL;
import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.HashSet;
import java.security.cert.CertSelector;
import java.security.cert.CertStore;
import java.security.cert.CertStoreException;
import java.security.cert.CertStoreParameters;
import java.security.cert.CollectionCertStoreParameters;
import java.security.cert.CRLSelector;
import java.security.cert.CertStoreSpi;


A CertStore that retrieves Certificates and
CRLs from a Collection.

 Before calling the engineGetCertificates or engineGetCRLs methods, the 
CollectionCertStore(CertStoreParameters) constructor is called to create the CertStore and establish the
Collection from which Certificates and
CRLs will be retrieved. If the specified
Collection contains an object that is not a
Certificate or CRL, that object will be
ignored.


Concurrent Access


As described in the javadoc for CertStoreSpi, the
engineGetCertificates and engineGetCRLs methods
must be thread-safe. That is, multiple threads may concurrently
invoke these methods on a single CollectionCertStore
object (or more than one) with no ill effects.


This is achieved by requiring that the Collection passed to the 
CollectionCertStore(CertStoreParameters) constructor (via the CollectionCertStoreParameters object) must have fail-fast
iterators. Simultaneous modifications to the Collection can thus be
detected and certificate or CRL retrieval can be retried. The fact that
Certificates and CRLs must be thread-safe is also
essential.

Author:     Steve Hanna
See Also:
Since:      1.4
/**
 * A <code>CertStore</code> that retrieves <code>Certificates</code> and
 * <code>CRL</code>s from a <code>Collection</code>.
 * <p>
 * Before calling the {@link #engineGetCertificates engineGetCertificates} or
 * {@link #engineGetCRLs engineGetCRLs} methods, the
 * {@link #CollectionCertStore(CertStoreParameters)
 * CollectionCertStore(CertStoreParameters)} constructor is called to
 * create the <code>CertStore</code> and establish the
 * <code>Collection</code> from which <code>Certificate</code>s and
 * <code>CRL</code>s will be retrieved. If the specified
 * <code>Collection</code> contains an object that is not a
 * <code>Certificate</code> or <code>CRL</code>, that object will be
 * ignored.
 * <p>
 * <b>Concurrent Access</b>
 * <p>
 * As described in the javadoc for <code>CertStoreSpi</code>, the
 * <code>engineGetCertificates</code> and <code>engineGetCRLs</code> methods
 * must be thread-safe. That is, multiple threads may concurrently
 * invoke these methods on a single <code>CollectionCertStore</code>
 * object (or more than one) with no ill effects.
 * <p>
 * This is achieved by requiring that the <code>Collection</code> passed to
 * the {@link #CollectionCertStore(CertStoreParameters)
 * CollectionCertStore(CertStoreParameters)} constructor (via the
 * <code>CollectionCertStoreParameters</code> object) must have fail-fast
 * iterators. Simultaneous modifications to the <code>Collection</code> can thus be
 * detected and certificate or CRL retrieval can be retried. The fact that
 * <code>Certificate</code>s and <code>CRL</code>s must be thread-safe is also
 * essential.
 *
 * @see java.security.cert.CertStore
 *
 * @since       1.4
 * @author      Steve Hanna
 */
public class CollectionCertStore extends CertStoreSpi {

    private Collection<?> coll;

    
Creates a CertStore with the specified parameters.
For this class, the parameters object must be an instance of
CollectionCertStoreParameters. The Collection
included in the CollectionCertStoreParameters object
must be thread-safe.

Params:
  • params – the algorithm parameters
Throws:
/**
     * Creates a <code>CertStore</code> with the specified parameters.
     * For this class, the parameters object must be an instance of
     * <code>CollectionCertStoreParameters</code>. The <code>Collection</code>
     * included in the <code>CollectionCertStoreParameters</code> object
     * must be thread-safe.
     *
     * @param params the algorithm parameters
     * @exception InvalidAlgorithmParameterException if params is not an
     *   instance of <code>CollectionCertStoreParameters</code>
     */
    public CollectionCertStore(CertStoreParameters params)
        throws InvalidAlgorithmParameterException
    {
        super(params);
        if (!(params instanceof CollectionCertStoreParameters))
            throw new InvalidAlgorithmParameterException(
                "parameters must be CollectionCertStoreParameters");
        coll = ((CollectionCertStoreParameters) params).getCollection();
    }

    
Returns a Collection of Certificates that
match the specified selector. If no Certificates
match the selector, an empty Collection will be returned.

Params:
  • selector – a CertSelector used to select which
 Certificates should be returned. Specify null
 to return all Certificates.
Throws:
Returns:a Collection of Certificates that
        match the specified selector
/**
     * Returns a <code>Collection</code> of <code>Certificate</code>s that
     * match the specified selector. If no <code>Certificate</code>s
     * match the selector, an empty <code>Collection</code> will be returned.
     *
     * @param selector a <code>CertSelector</code> used to select which
     *  <code>Certificate</code>s should be returned. Specify <code>null</code>
     *  to return all <code>Certificate</code>s.
     * @return a <code>Collection</code> of <code>Certificate</code>s that
     *         match the specified selector
     * @throws CertStoreException if an exception occurs
     */
    @Override
    public Collection<Certificate> engineGetCertificates
            (CertSelector selector) throws CertStoreException {
        if (coll == null) {
            throw new CertStoreException("Collection is null");
        }
        // Tolerate a few ConcurrentModificationExceptions
        for (int c = 0; c < 10; c++) {
            try {
                HashSet<Certificate> result = new HashSet<>();
                if (selector != null) {
                    for (Object o : coll) {
                        if ((o instanceof Certificate) &&
                            selector.match((Certificate) o))
                            result.add((Certificate)o);
                    }
                } else {
                    for (Object o : coll) {
                        if (o instanceof Certificate)
                            result.add((Certificate)o);
                    }
                }
                return(result);
            } catch (ConcurrentModificationException e) { }
        }
        throw new ConcurrentModificationException("Too many "
            + "ConcurrentModificationExceptions");
    }

    
Returns a Collection of CRLs that
match the specified selector. If no CRLs
match the selector, an empty Collection will be returned.

Params:
  • selector – a CRLSelector used to select which
 CRLs should be returned. Specify null
 to return all CRLs.
Throws:
Returns:a Collection of CRLs that
        match the specified selector
/**
     * Returns a <code>Collection</code> of <code>CRL</code>s that
     * match the specified selector. If no <code>CRL</code>s
     * match the selector, an empty <code>Collection</code> will be returned.
     *
     * @param selector a <code>CRLSelector</code> used to select which
     *  <code>CRL</code>s should be returned. Specify <code>null</code>
     *  to return all <code>CRL</code>s.
     * @return a <code>Collection</code> of <code>CRL</code>s that
     *         match the specified selector
     * @throws CertStoreException if an exception occurs
     */
    @Override
    public Collection<CRL> engineGetCRLs(CRLSelector selector)
        throws CertStoreException
    {
        if (coll == null)
            throw new CertStoreException("Collection is null");

        // Tolerate a few ConcurrentModificationExceptions
        for (int c = 0; c < 10; c++) {
            try {
                HashSet<CRL> result = new HashSet<>();
                if (selector != null) {
                    for (Object o : coll) {
                        if ((o instanceof CRL) && selector.match((CRL) o))
                            result.add((CRL)o);
                    }
                } else {
                    for (Object o : coll) {
                        if (o instanceof CRL)
                            result.add((CRL)o);
                    }
                }
                return result;
            } catch (ConcurrentModificationException e) { }
        }
        throw new ConcurrentModificationException("Too many "
            + "ConcurrentModificationExceptions");
    }
}