/* HttpsCertVerifier.java
   Copyright (C) 2009 Red Hat, Inc.

This file is part of IcedTea.

IcedTea is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as published by
the Free Software Foundation, version 2.

IcedTea 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 for more details.

You should have received a copy of the GNU General Public License
along with IcedTea; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version.
*/

package net.sourceforge.jnlp.security;

import static net.sourceforge.jnlp.runtime.Translator.R;

import java.io.IOException;
import java.security.KeyStore;
import java.security.cert.CertPath;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.CertificateExpiredException;
import java.security.cert.CertificateFactory;
import java.security.cert.CertificateNotYetValidException;
import java.security.cert.CertificateParsingException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import sun.security.util.DerValue;
import sun.security.util.HostnameChecker;
import sun.security.x509.X500Name;

public class HttpsCertVerifier implements CertVerifier {

    private X509Certificate[] chain;
    private String authType;
    private String hostName;
    private boolean isTrusted;
    private boolean hostMatched;
    private ArrayList<String> details = new ArrayList<String>();

    public HttpsCertVerifier(X509Certificate[] chain, String authType,
                             boolean isTrusted, boolean hostMatched,
                             String hostName) {
        this.chain = chain;
        this.authType = authType;
        this.hostName = hostName;
        this.isTrusted = isTrusted;
        this.hostMatched = hostMatched;
    }

    public boolean getAlreadyTrustPublisher() {
        return isTrusted;
    }

    public CertPath getCertPath() {

        ArrayList<X509Certificate> list = new ArrayList<X509Certificate>();
        for (int i = 0; i < chain.length; i++)
            list.add(chain[i]);

        ArrayList<CertPath> certPaths = new ArrayList<CertPath>();

        try {
            certPaths.add(CertificateFactory.getInstance("X.509").generateCertPath(list));
        } catch (CertificateException ce) {
            ce.printStackTrace();

            // carry on
        }

        return certPaths.get(0);
    }

    public ArrayList<String> getDetails() {

        boolean hasExpiredCert = false;
        boolean hasExpiringCert = false;
        boolean notYetValidCert = false;
        boolean isUntrusted = false;
        boolean CNMisMatch = !hostMatched;

        if (!getAlreadyTrustPublisher())
            isUntrusted = true;

        for (int i = 0; i < chain.length; i++) {
            X509Certificate cert = chain[i];

            long now = System.currentTimeMillis();
            long SIX_MONTHS = 180 * 24 * 60 * 60 * 1000L;
            long notAfter = cert.getNotAfter().getTime();
            if (notAfter < now) {
                hasExpiredCert = true;
            } else if (notAfter < now + SIX_MONTHS) {
                hasExpiringCert = true;
            }

            try {
                cert.checkValidity();
            } catch (CertificateNotYetValidException cnyve) {
                notYetValidCert = true;
            } catch (CertificateExpiredException cee) {
                hasExpiredCert = true;
            }
        }

        String altNames = getNamesForCert(chain[0]);

        if (isUntrusted || hasExpiredCert || hasExpiringCert || notYetValidCert || CNMisMatch) {
            if (isUntrusted)
                addToDetails(R("SUntrustedCertificate"));
            if (hasExpiredCert)
                addToDetails(R("SHasExpiredCert"));
            if (hasExpiringCert)
                addToDetails(R("SHasExpiringCert"));
            if (notYetValidCert)
                addToDetails(R("SNotYetValidCert"));
            if (CNMisMatch)
                addToDetails(R("SCNMisMatch", altNames, this.hostName));
        }

        return details;
    }

    private String getNamesForCert(X509Certificate c) {

        String names = "";

        // We use the specification from
        // http://java.sun.com/j2se/1.5.0/docs/api/java/security/cert/X509Certificate.html#getSubjectAlternativeNames()
        // to determine the type of address
        int ALTNAME_DNS = 2;
        int ALTNAME_IP = 7;

        try {
            Collection<List<?>> subjAltNames = c.getSubjectAlternativeNames();
            X500Name subjectName = HostnameChecker.getSubjectX500Name(c);
            DerValue derValue = subjectName.findMostSpecificAttribute
                                                        (X500Name.commonName_oid);
            names += derValue.getAsString();

            if (subjAltNames != null) {
                for (List<?> next : subjAltNames) {
                    if (((Integer) next.get(0)).intValue() == ALTNAME_IP ||
                            ((Integer) next.get(0)).intValue() == ALTNAME_DNS) {
                        names += ", " + (String) next.get(1);
                    }
                }
            }

            if (subjAltNames != null)
                names = names.substring(2); // remove proceeding ", "

        } catch (CertificateParsingException cpe) {
            cpe.printStackTrace();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }

        return names;
    }

    private void addToDetails(String detail) {
        if (!details.contains(detail))
            details.add(detail);
    }

    public Certificate getPublisher() {
        if (chain.length > 0)
            return (Certificate) chain[0];
        return null;
    }

    public Certificate getRoot() {
        if (chain.length > 0)
            return (Certificate) chain[chain.length - 1];
        return null;
    }

    public boolean getRootInCacerts() {
        try {
            KeyStore[] caCertsKeyStores = KeyStores.getCAKeyStores();
            return CertificateUtils.inKeyStores((X509Certificate) getRoot(), caCertsKeyStores);
        } catch (Exception e) {
        }
        return false;
    }

    public boolean hasSigningIssues() {
        return false;
    }

    public boolean noSigningIssues() {
        return false;
    }

}