/*
 * Copyright (c) 2000, 2017 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package com.sun.messaging.jms.ra;

import javax.resource.spi.security.PasswordCredential;

import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.security.auth.Subject;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Iterator;
import java.util.Set;

/**
 * Util methods for the Sun MQ Resource Adapter for JMS
 */

public class Util {
    /** Disable Constructor */
    private Util() {
    }

    /**
     * Generic equals method
     *
     * @param a object 1
     * @param b object 2
     *
     * @return true if objects a and b are equal; false otherwise
     */
    static public boolean isEqual(Object a, Object b) {
        if (a == null) {
            return (b == null);
        } else {
            return a.equals(b);
        }
    }

    /**
     * Checks two PassWordCredential instances for equality
     *
     * @param a PasswordCredential 1
     * @param b PasswordCredential 2
     *
     * @return true if PasswordCredential a and PasswordCredential b are equal; false otherwise
     */
    static public boolean isPasswordCredentialEqual(PasswordCredential a, PasswordCredential b) {
        if (a == b) {
            return true;
        }
        if ((a == null) && (b != null)) {
            return false;
        }
        if ((a != null) && (b == null))
            return false;
        if (!isEqual(a.getUserName(), b.getUserName())) {
            return false;
        }

        String p1 = null;
        String p2 = null;

        if (a.getPassword() != null) {
            p1 = new String(a.getPassword());
        }
        if (b.getPassword() != null) {
            p2 = new String(b.getPassword());
        }
        return (isEqual(p1, p2));
    }

    /**
     * Returns a PasswordCredential by resolving the ManagedConnectionFactory, Subject, and ConnectionRequestInfo passed in.
     * 
     * If the Subject is non-null, non-empty, it will be the src of the pc info. else, if it is empty, the MCF should be
     * used else if it null, the CRI, is used if non-empty else the MCF is used.
     *
     * @return The PasswordCredential
     */
    static public PasswordCredential getPasswordCredential(final com.sun.messaging.jms.ra.ManagedConnectionFactory mcf, final Subject subject,
            com.sun.messaging.jms.ra.ConnectionRequestInfo myinfo) throws javax.resource.ResourceException {
        String username2use = null;
        String password2use = null;

        PasswordCredential pc = null;

        // System.out.println("MQRA:U:getPC()-subject="+subject+":CRInfo="+myinfo);
        if (subject != null) {
            // System.out.println("MQRA:U:getPC:non-null subject");
            pc = (PasswordCredential) AccessController.doPrivileged(new PrivilegedAction<Object>() {
                public Object run() {
                    Set creds = subject.getPrivateCredentials(PasswordCredential.class);
                    if (creds == null) {
                        // System.out.println("MQRA:U:getPC:null creds-return null pc");
                        return null;
                    }
                    Iterator iter = creds.iterator();
                    while (iter.hasNext()) {
                        PasswordCredential temp = (PasswordCredential) iter.next();
                        if (temp != null) {
                            // System.out.println("MQRA:U:getPC:pwc from subject="+temp.toString());
                            // Sufficient if username is non-null; do not retrieve the pw
                            if (temp.getUserName() != null) {
                                // System.out.println("MQRA:U:getPC:un+pw exist;return pwc="+temp.toString());
                                return temp;
                            }
                        }
                    }
                    // System.out.println("MQRA:U:getPC:null or empty subject-return null pc");
                    return null;
                }
            });
        }
        // Return only if a valid PasswordCredential is obtained
        if (pc != null) {
            // System.out.println("MQRA:U:getPC:-returning real pc from Subject");
            return pc;
        } else {
            // else need to construct a pc from CRI or MCF
            if (myinfo != null) {
                if (myinfo.getUserName() != null) {
                    // System.out.println("MQRA:U:getPC():non-null CRI:creating pwc from CRI");
                    username2use = myinfo.getUserName();
                    password2use = myinfo.getPassword();
                } else {
                    // System.out.println("MQRA:U:getPC():non-null CRI BUT un==null:creating pwc from MCF");
                    username2use = mcf.getUserName();
                    password2use = mcf.getPassword();
                }
            } else {
                // need to construct a pc from MCF
                // System.out.println("MQRA:U:getPC():null CRI:creating pwc from MCF");
                username2use = mcf.getUserName();
                password2use = mcf.getPassword();

            }
            char[] password = password2use.toCharArray();
            pc = new PasswordCredential(username2use, password);
            // System.out.println("MQRA:U:getPC:-returning pc from CRI/MCF");
            return pc;
        }
    }

    /**
     * Returns whether a Subject has a valid PasswordCredential or not. A valid PWC is a non-null, non-empty username in the
     * PWC of the subject
     * 
     * @return true if subject has a valid PWC; false otherwise
     */
    static public boolean isPasswordCredentialValid(final Subject subject) throws javax.resource.ResourceException {
        if (subject == null) {
            return false;
        }
        Boolean pwcValid = (Boolean) AccessController.doPrivileged(new PrivilegedAction<Object>() {
            public Object run() {
                Set creds = subject.getPrivateCredentials(PasswordCredential.class);
                if (creds == null) {
                    return Boolean.valueOf(false);
                }
                Iterator iter = creds.iterator();
                String un;
                while (iter.hasNext()) {
                    PasswordCredential temp = (PasswordCredential) iter.next();
                    if (temp != null) {
                        un = temp.getUserName();
                        if (un != null && !("".equals(un))) {
                            return Boolean.valueOf(true);
                        }
                    }
                }
                return Boolean.valueOf(false);
            }
        });
        return pwcValid.booleanValue();
    }

    /**
     * Returns a PasswordCredential by resolving the ManagedConnectionFactory, Subject, and ConnectionRequestInfo passed in.
     * 
     * If the Subject is non-null, non-empty, it will be the src of the pc info. else, if it is empty, the MCF should be
     * used else if it null, the CRI, is used if non-empty else the MCF is used.
     *
     * @return The PasswordCredential
     */
    static public PasswordCredential getPasswordCredentialOld(final com.sun.messaging.jms.ra.ManagedConnectionFactory mcf, final Subject subject,
            com.sun.messaging.jms.ra.ConnectionRequestInfo myinfo) throws javax.resource.ResourceException {
        // System.out.println("MQRA:U:getPC()-"+subject+":CRInfo="+myinfo);
        if (subject == null) {
            // System.out.println("MQRA:U:getPC:-null subject");
            if (myinfo == null) {
                // System.out.println("MQRA:U:getPC:-no crinfo;returning null");
                return null;
            } else {
                // Can't create a PC with null values
                if (myinfo.getUserName() == null || myinfo.getPassword() == null) {
                    // System.out.println("MQRA:U:getPC()-null un+pw;returning null");
                    return null;
                }
                char[] password = myinfo.getPassword().toCharArray();

                PasswordCredential pc = new PasswordCredential(myinfo.getUserName(), password);

                pc.setManagedConnectionFactory((javax.resource.spi.ManagedConnectionFactory) mcf);
                // System.out.println("MQRA:U:getPC:-returning real pc");
                return pc;
            }
        } else {
            // System.out.println("MQRA:U:getPC:non-null subject");
            PasswordCredential pc = (PasswordCredential) AccessController.doPrivileged(new PrivilegedAction<Object>() {
                public Object run() {
                    Set creds = subject.getPrivateCredentials(PasswordCredential.class);
                    Iterator iter = creds.iterator();
                    while (iter.hasNext()) {
                        PasswordCredential temp = (PasswordCredential) iter.next();
                        // if (temp != null) {
                        // System.out.println("MQRA:U:getPC:pwc from subject="+temp.toString());
                        // }
                        if (temp != null && temp.getManagedConnectionFactory() != null && temp.getManagedConnectionFactory().equals(mcf)) {
                            // System.out.println("MQRA:U:getPC:mcf == subject mcf-return real pc");
                            return temp;
                        }
                    }
                    // System.out.println("MQRA:U:getPC:mcf != subject mcf-return null pc");
                    return null;
                }
            });
            if (pc == null) {
                // System.out.println("MQRA:U:getPC:null pc;throw exc-null credentials");
                throw new javax.resource.spi.SecurityException("MQRA:U:getPC:Null credentials");
            } else {
                // System.out.println("MQRA:U:getPC():returning a valid pc");
                return pc;
            }
        }
    }

    public static Object jndiLookup(String jndiName) throws NamingException {
        InitialContext ic = null;
        Object obj = null;
        try {
            ic = new InitialContext();
            obj = ic.lookup(jndiName);
        } finally {
            if (ic != null) {
                try {
                    ic.close();
                } catch (Exception e) {
                }
            }
        }
        return obj;
    }
}
