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package sun.security.provider.certpath;
import java.util.*;
import java.security.InvalidAlgorithmParameterException;
import java.security.cert.*;
import javax.security.auth.x500.X500Principal;
/**
* A <code>CertStore</code> that retrieves <code>Certificates</code> and
* <code>CRL</code>s from a <code>Collection</code>.
* <p>
* This implementation is functionally equivalent to CollectionCertStore
* with two differences:
* <ol>
* <li>Upon construction, the elements in the specified Collection are
* partially indexed. X509Certificates are indexed by subject, X509CRLs
* by issuer, non-X509 Certificates and CRLs are copied without indexing,
* other objects are ignored. This increases CertStore construction time
* but allows significant speedups for searches which specify the indexed
* attributes, in particular for large Collections (reduction from linear
* time to effectively constant time). Searches for non-indexed queries
* are as fast (or marginally faster) than for the standard
* CollectionCertStore. Certificate subjects and CRL issuers
* were found to be specified in most searches used internally by the
* CertPath provider. Additional attributes could indexed if there are
* queries that justify the effort.
*
* <li>Changes to the specified Collection after construction time are
* not detected and ignored. This is because there is no way to efficiently
* detect if a Collection has been modified, a full traversal would be
* required. That would degrade lookup performance to linear time and
* eliminated the benefit of indexing. We may fix this via the introduction
* of new public APIs in the future.
* </ol>
* <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
* @see CollectionCertStore
*
* @author Andreas Sterbenz
*/
public class IndexedCollectionCertStore extends CertStoreSpi {
/**
* Map X500Principal(subject) -> X509Certificate | List of X509Certificate
*/
private Map<X500Principal, Object> certSubjects;
/**
* Map X500Principal(issuer) -> X509CRL | List of X509CRL
*/
private Map<X500Principal, Object> crlIssuers;
/**
* Sets of non-X509 certificates and CRLs
*/
private Set<Certificate> otherCertificates;
private Set<CRL> otherCRLs;
/**
* Creates a <code>CertStore</code> with the specified parameters.
* For this class, the parameters object must be an instance of
* <code>CollectionCertStoreParameters</code>.
*
* @param params the algorithm parameters
* @exception InvalidAlgorithmParameterException if params is not an
* instance of <code>CollectionCertStoreParameters</code>
*/
public IndexedCollectionCertStore(CertStoreParameters params)
throws InvalidAlgorithmParameterException {
super(params);
if (!(params instanceof CollectionCertStoreParameters)) {
throw new InvalidAlgorithmParameterException(
"parameters must be CollectionCertStoreParameters");
}
Collection<?> coll = ((CollectionCertStoreParameters)params).getCollection();
if (coll == null) {
throw new InvalidAlgorithmParameterException
("Collection must not be null");
}
buildIndex(coll);
}
/**
* Index the specified Collection copying all references to Certificates
* and CRLs.
*/
private void buildIndex(Collection<?> coll) {
certSubjects = new HashMap<X500Principal, Object>();
crlIssuers = new HashMap<X500Principal, Object>();
otherCertificates = null;
otherCRLs = null;
for (Object obj : coll) {
if (obj instanceof X509Certificate) {
indexCertificate((X509Certificate)obj);
} else if (obj instanceof X509CRL) {
indexCRL((X509CRL)obj);
} else if (obj instanceof Certificate) {
if (otherCertificates == null) {
otherCertificates = new HashSet<Certificate>();
}
otherCertificates.add((Certificate)obj);
} else if (obj instanceof CRL) {
if (otherCRLs == null) {
otherCRLs = new HashSet<CRL>();
}
otherCRLs.add((CRL)obj);
} else {
// ignore
}
}
if (otherCertificates == null) {
otherCertificates = Collections.<Certificate>emptySet();
}
if (otherCRLs == null) {
otherCRLs = Collections.<CRL>emptySet();
}
}
/**
* Add an X509Certificate to the index.
*/
private void indexCertificate(X509Certificate cert) {
X500Principal subject = cert.getSubjectX500Principal();
Object oldEntry = certSubjects.put(subject, cert);
if (oldEntry != null) { // assume this is unlikely
if (oldEntry instanceof X509Certificate) {
if (cert.equals(oldEntry)) {
return;
}
List<X509Certificate> list = new ArrayList<X509Certificate>(2);
list.add(cert);
list.add((X509Certificate)oldEntry);
certSubjects.put(subject, list);
} else {
List<X509Certificate> list = (List<X509Certificate>)oldEntry;
if (list.contains(cert) == false) {
list.add(cert);
}
certSubjects.put(subject, list);
}
}
}
/**
* Add an X509CRL to the index.
*/
private void indexCRL(X509CRL crl) {
X500Principal issuer = crl.getIssuerX500Principal();
Object oldEntry = crlIssuers.put(issuer, crl);
if (oldEntry != null) { // assume this is unlikely
if (oldEntry instanceof X509CRL) {
if (crl.equals(oldEntry)) {
return;
}
List<X509CRL> list = new ArrayList<X509CRL>(2);
list.add(crl);
list.add((X509CRL)oldEntry);
crlIssuers.put(issuer, list);
} else {
List<X509CRL> list = (List<X509CRL>)oldEntry;
if (list.contains(crl) == false) {
list.add(crl);
}
crlIssuers.put(issuer, list);
}
}
}
/**
* 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
*/
public Collection<? extends Certificate> engineGetCertificates(CertSelector selector)
throws CertStoreException {
// no selector means match all
if (selector == null) {
Set<Certificate> matches = new HashSet<Certificate>();
matchX509Certs(new X509CertSelector(), matches);
matches.addAll(otherCertificates);
return matches;
}
if (selector instanceof X509CertSelector == false) {
Set<Certificate> matches = new HashSet<Certificate>();
matchX509Certs(selector, matches);
for (Certificate cert : otherCertificates) {
if (selector.match(cert)) {
matches.add(cert);
}
}
return matches;
}
if (certSubjects.isEmpty()) {
return Collections.<X509Certificate>emptySet();
}
X509CertSelector x509Selector = (X509CertSelector)selector;
// see if the subject is specified
X500Principal subject;
X509Certificate matchCert = x509Selector.getCertificate();
if (matchCert != null) {
subject = matchCert.getSubjectX500Principal();
} else {
subject = x509Selector.getSubject();
}
if (subject != null) {
// yes, narrow down candidates to indexed possibilities
Object entry = certSubjects.get(subject);
if (entry == null) {
return Collections.<X509Certificate>emptySet();
}
if (entry instanceof X509Certificate) {
X509Certificate x509Entry = (X509Certificate)entry;
if (x509Selector.match(x509Entry)) {
return Collections.singleton(x509Entry);
} else {
return Collections.<X509Certificate>emptySet();
}
} else {
List<X509Certificate> list = (List<X509Certificate>)entry;
Set<X509Certificate> matches = new HashSet<X509Certificate>(16);
for (X509Certificate cert : list) {
if (x509Selector.match(cert)) {
matches.add(cert);
}
}
return matches;
}
}
// cannot use index, iterate all
Set<Certificate> matches = new HashSet<Certificate>(16);
matchX509Certs(x509Selector, matches);
return matches;
}
/**
* Iterate through all the X509Certificates and add matches to the
* collection.
*/
private void matchX509Certs(CertSelector selector,
Collection<Certificate> matches) {
for (Object obj : certSubjects.values()) {
if (obj instanceof X509Certificate) {
X509Certificate cert = (X509Certificate)obj;
if (selector.match(cert)) {
matches.add(cert);
}
} else {
List<X509Certificate> list = (List<X509Certificate>)obj;
for (X509Certificate cert : list) {
if (selector.match(cert)) {
matches.add(cert);
}
}
}
}
}
/**
* 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
*/
public Collection<CRL> engineGetCRLs(CRLSelector selector)
throws CertStoreException {
if (selector == null) {
Set<CRL> matches = new HashSet<CRL>();
matchX509CRLs(new X509CRLSelector(), matches);
matches.addAll(otherCRLs);
return matches;
}
if (selector instanceof X509CRLSelector == false) {
Set<CRL> matches = new HashSet<CRL>();
matchX509CRLs(selector, matches);
for (CRL crl : otherCRLs) {
if (selector.match(crl)) {
matches.add(crl);
}
}
return matches;
}
if (crlIssuers.isEmpty()) {
return Collections.<CRL>emptySet();
}
X509CRLSelector x509Selector = (X509CRLSelector)selector;
// see if the issuer is specified
Collection<X500Principal> issuers = x509Selector.getIssuers();
if (issuers != null) {
HashSet<CRL> matches = new HashSet<CRL>(16);
for (X500Principal issuer : issuers) {
Object entry = crlIssuers.get(issuer);
if (entry == null) {
// empty
} else if (entry instanceof X509CRL) {
X509CRL crl = (X509CRL)entry;
if (x509Selector.match(crl)) {
matches.add(crl);
}
} else { // List
List<X509CRL> list = (List<X509CRL>)entry;
for (X509CRL crl : list) {
if (x509Selector.match(crl)) {
matches.add(crl);
}
}
}
}
return matches;
}
// cannot use index, iterate all
Set<CRL> matches = new HashSet<CRL>(16);
matchX509CRLs(x509Selector, matches);
return matches;
}
/**
* Iterate through all the X509CRLs and add matches to the
* collection.
*/
private void matchX509CRLs(CRLSelector selector, Collection<CRL> matches) {
for (Object obj : crlIssuers.values()) {
if (obj instanceof X509CRL) {
X509CRL crl = (X509CRL)obj;
if (selector.match(crl)) {
matches.add(crl);
}
} else {
List<X509CRL> list = (List<X509CRL>)obj;
for (X509CRL crl : list) {
if (selector.match(crl)) {
matches.add(crl);
}
}
}
}
}
}