src/java.base/share/classes/sun/security/util/AnchorCertificates.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
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package sun.security.util;

import java.io.File;
import java.io.FileInputStream;
import java.security.KeyStore;
import java.security.cert.X509Certificate;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;

import javax.security.auth.x500.X500Principal;
import sun.security.x509.X509CertImpl;

/**
 * The purpose of this class is to determine the trust anchor certificates is in
 * the cacerts file.  This is used for PKIX CertPath checking.
 */
public class AnchorCertificates {

    private static final Debug debug = Debug.getInstance("certpath");
    private static final String HASH = "SHA-256";
    private static Set<String> certs = Collections.emptySet();
    private static Set<X500Principal> certIssuers = Collections.emptySet();

    static  {
        File f = new File(FilePaths.cacerts());
        try {
            KeyStore cacerts = KeyStore.getInstance("JKS");
            try (FileInputStream fis = new FileInputStream(f)) {
                cacerts.load(fis, null);
                certs = new HashSet<>();
                certIssuers = new HashSet<>();
                Enumeration<String> list = cacerts.aliases();
                while (list.hasMoreElements()) {
                    String alias = list.nextElement();
                    // Check if this cert is labeled a trust anchor.
                    if (alias.contains(" [jdk")) {
                        X509Certificate cert = (X509Certificate) cacerts
                                .getCertificate(alias);
                        String fp =
                            X509CertImpl.getFingerprint(HASH, cert, debug);
                        // only add trust anchor if fingerprint can
                        // be calculated
                        if (fp != null) {
                            certs.add(fp);
                            certIssuers.add(cert.getSubjectX500Principal());
                        }
                    }
                }
            }
        } catch (Exception e) {
            if (debug != null) {
                debug.println("Error parsing cacerts");
                e.printStackTrace();
            }
        }
    }

    /**
     * Checks if a certificate is a JDK trust anchor.
     *
     * @param cert the certificate to check
     * @return true if the certificate is a JDK trust anchor
     */
    public static boolean contains(X509Certificate cert) {
        String key = X509CertImpl.getFingerprint(HASH, cert, debug);
        boolean result = (key != null && certs.contains(key));
        if (result && debug != null) {
            debug.println("AnchorCertificate.contains: matched " +
                    cert.getSubjectX500Principal());
        }
        return result;
    }

    /**
     * Checks if a JDK trust anchor is the issuer of a certificate.
     *
     * @param cert the certificate to check
     * @return true if the certificate is issued by a trust anchor
     */
    public static boolean issuerOf(X509Certificate cert) {
        return certIssuers.contains(cert.getIssuerX500Principal());
    }

    private AnchorCertificates() {}
}