/*

 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * 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).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package javax.security.auth;

import java.util.*;

import java.text.MessageFormat;

import java.security.Permission;

import java.security.PermissionCollection;

import java.security.Principal;

import sun.security.util.ResourcesMgr;

/**

 * This class is used to protect access to private Credentials

 * belonging to a particular {@code Subject}.  The {@code Subject}

 * is represented by a Set of Principals.

 *

 * <p> The target name of this {@code Permission} specifies

 * a Credential class name, and a Set of Principals.

 * The only valid value for this Permission's actions is, "read".

 * The target name must abide by the following syntax:

 *

 * <pre>

 *      CredentialClass {PrincipalClass "PrincipalName"}*

 * </pre>

 *

 * For example, the following permission grants access to the

 * com.sun.PrivateCredential owned by Subjects which have

 * a com.sun.Principal with the name, "duke".  Note that although

 * this example, as well as all the examples below, do not contain

 * Codebase, SignedBy, or Principal information in the grant statement

 * (for simplicity reasons), actual policy configurations should

 * specify that information when appropriate.

 *

 * <pre>

 *

 *    grant {

 *      permission javax.security.auth.PrivateCredentialPermission

 *              "com.sun.PrivateCredential com.sun.Principal \"duke\"",

 *              "read";

 *    };

 * </pre>

 *

 * If CredentialClass is "*", then access is granted to

 * all private Credentials belonging to the specified

 * {@code Subject}.

 * If "PrincipalName" is "*", then access is granted to the

 * specified Credential owned by any {@code Subject} that has the

 * specified {@code Principal} (the actual PrincipalName doesn't matter).

 * For example, the following grants access to the

 * a.b.Credential owned by any {@code Subject} that has

 * an a.b.Principal.

 *

 * <pre>

 *    grant {

 *      permission javax.security.auth.PrivateCredentialPermission

 *              "a.b.Credential a.b.Principal "*"",

 *              "read";

 *    };

 * </pre>

 *

 * If both the PrincipalClass and "PrincipalName" are "*",

 * then access is granted to the specified Credential owned by

 * any {@code Subject}.

 *

 * <p> In addition, the PrincipalClass/PrincipalName pairing may be repeated:

 *

 * <pre>

 *    grant {

 *      permission javax.security.auth.PrivateCredentialPermission

 *              "a.b.Credential a.b.Principal "duke" c.d.Principal "dukette"",

 *              "read";

 *    };

 * </pre>

 *

 * The above grants access to the private Credential, "a.b.Credential",

 * belonging to a {@code Subject} with at least two associated Principals:

 * "a.b.Principal" with the name, "duke", and "c.d.Principal", with the name,

 * "dukette".

 *

 * @since 1.4

 */

public final class PrivateCredentialPermission extends Permission {

    @java.io.Serial

    private static final long serialVersionUID = 5284372143517237068L;

    private static final CredOwner[] EMPTY_PRINCIPALS = new CredOwner[0];

    /**

     * @serial

     */

    private String credentialClass;

    /**

     * @serial The Principals associated with this permission.

     *          The set contains elements of type,

     *          {@code PrivateCredentialPermission.CredOwner}.

     */

    @SuppressWarnings("serial") // Not statically typed as Serializable

    private Set<Principal> principals;  // ignored - kept around for compatibility

    private transient CredOwner[] credOwners;

    /**

     * @serial

     */

    private boolean testing = false;

    /**

     * Create a new {@code PrivateCredentialPermission}

     * with the specified {@code credentialClass} and Principals.

     */

    PrivateCredentialPermission(String credentialClass,

                        Set<Principal> principals) {

        super(credentialClass);

        this.credentialClass = credentialClass;

        synchronized(principals) {

            if (principals.size() == 0) {

                this.credOwners = EMPTY_PRINCIPALS;

            } else {

                this.credOwners = new CredOwner[principals.size()];

                int index = 0;

                Iterator<Principal> i = principals.iterator();

                while (i.hasNext()) {

                    Principal p = i.next();

                    this.credOwners[index++] = new CredOwner

                                                (p.getClass().getName(),

                                                p.getName());

                }

            }

        }

    }

    /**

     * Creates a new {@code PrivateCredentialPermission}

     * with the specified {@code name}.  The {@code name}

     * specifies both a Credential class and a {@code Principal} Set.

     *

     * @param name the name specifying the Credential class and

     *          {@code Principal} Set.

     *

     * @param actions the actions specifying that the Credential can be read.

     *

     * @throws IllegalArgumentException if {@code name} does not conform

     *          to the correct syntax or if {@code actions} is not "read".

     */

    public PrivateCredentialPermission(String name, String actions) {

        super(name);

        if (!"read".equalsIgnoreCase(actions))

            throw new IllegalArgumentException

                (ResourcesMgr.getString("actions.can.only.be.read."));

        init(name);

    }

    /**

     * Returns the Class name of the Credential associated with this

     * {@code PrivateCredentialPermission}.

     *

     * @return the Class name of the Credential associated with this

     *          {@code PrivateCredentialPermission}.

     */

    public String getCredentialClass() {

        return credentialClass;

    }

    /**

     * Returns the {@code Principal} classes and names

     * associated with this {@code PrivateCredentialPermission}.

     * The information is returned as a two-dimensional array (array[x][y]).

     * The 'x' value corresponds to the number of {@code Principal}

     * class and name pairs.  When (y==0), it corresponds to

     * the {@code Principal} class value, and when (y==1),

     * it corresponds to the {@code Principal} name value.

     * For example, array[0][0] corresponds to the class name of

     * the first {@code Principal} in the array.  array[0][1]

     * corresponds to the {@code Principal} name of the

     * first {@code Principal} in the array.

     *

     * @return the {@code Principal} class and names associated

     *          with this {@code PrivateCredentialPermission}.

     */

    public String[][] getPrincipals() {

        if (credOwners == null || credOwners.length == 0) {

            return new String[0][0];

        }

        String[][] pArray = new String[credOwners.length][2];

        for (int i = 0; i < credOwners.length; i++) {

            pArray[i][0] = credOwners[i].principalClass;

            pArray[i][1] = credOwners[i].principalName;

        }

        return pArray;

    }

    /**

     * Checks if this {@code PrivateCredentialPermission} implies

     * the specified {@code Permission}.

     *

     * <p>

     *

     * This method returns true if:

     * <ul>

     * <li> {@code p} is an instanceof PrivateCredentialPermission and

     * <li> the target name for {@code p} is implied by this object's

     *          target name.  For example:

     * <pre>

     *  [* P1 "duke"] implies [a.b.Credential P1 "duke"].

     *  [C1 P1 "duke"] implies [C1 P1 "duke" P2 "dukette"].

     *  [C1 P2 "dukette"] implies [C1 P1 "duke" P2 "dukette"].

     * </pre>

     * </ul>

     *

     * @param p the {@code Permission} to check against.

     *

     * @return true if this {@code PrivateCredentialPermission} implies

     * the specified {@code Permission}, false if not.

     */

    public boolean implies(Permission p) {

        if (p == null || !(p instanceof PrivateCredentialPermission))

            return false;

        PrivateCredentialPermission that = (PrivateCredentialPermission)p;

        if (!impliesCredentialClass(credentialClass, that.credentialClass))

            return false;

        return impliesPrincipalSet(credOwners, that.credOwners);

    }

    /**

     * Checks two {@code PrivateCredentialPermission} objects for

     * equality.  Checks that {@code obj} is a

     * {@code PrivateCredentialPermission},

     * and has the same credential class as this object,

     * as well as the same Principals as this object.

     * The order of the Principals in the respective Permission's

     * target names is not relevant.

     *

     * @param obj the object we are testing for equality with this object.

     *

     * @return true if obj is a {@code PrivateCredentialPermission},

     *          has the same credential class as this object,

     *          and has the same Principals as this object.

     */

    public boolean equals(Object obj) {

        if (obj == this)

            return true;

        if (! (obj instanceof PrivateCredentialPermission))

            return false;

        PrivateCredentialPermission that = (PrivateCredentialPermission)obj;

        return (this.implies(that) && that.implies(this));

    }

    /**

     * Returns the hash code value for this object.

     *

     * @return a hash code value for this object.

     */

    public int hashCode() {

        return this.credentialClass.hashCode();

    }

    /**

     * Returns the "canonical string representation" of the actions.

     * This method always returns the String, "read".

     *

     * @return the actions (always returns "read").

     */

    public String getActions() {

        return "read";

    }

    /**

     * Return a homogeneous collection of PrivateCredentialPermissions

     * in a {@code PermissionCollection}.

     * No such {@code PermissionCollection} is defined,

     * so this method always returns {@code null}.

     *

     * @return null in all cases.

     */

    public PermissionCollection newPermissionCollection() {

        return null;

    }

    private void init(String name) {

        if (name == null || name.trim().isEmpty()) {

            throw new IllegalArgumentException("invalid empty name");

        }

        ArrayList<CredOwner> pList = new ArrayList<>();

        StringTokenizer tokenizer = new StringTokenizer(name, " ", true);

        String principalClass = null;

        String principalName = null;

        if (testing)

            System.out.println("whole name = " + name);

        // get the Credential Class

        credentialClass = tokenizer.nextToken();

        if (testing)

            System.out.println("Credential Class = " + credentialClass);

        if (tokenizer.hasMoreTokens() == false) {

            MessageFormat form = new MessageFormat(ResourcesMgr.getString

                ("permission.name.name.syntax.invalid."));

            Object[] source = {name};

            throw new IllegalArgumentException

                (form.format(source) + ResourcesMgr.getString

                        ("Credential.Class.not.followed.by.a.Principal.Class.and.Name"));

        }

        while (tokenizer.hasMoreTokens()) {

            // skip delimiter

            tokenizer.nextToken();

            // get the Principal Class

            principalClass = tokenizer.nextToken();

            if (testing)

                System.out.println("    Principal Class = " + principalClass);

            if (tokenizer.hasMoreTokens() == false) {

                MessageFormat form = new MessageFormat(ResourcesMgr.getString

                        ("permission.name.name.syntax.invalid."));

                Object[] source = {name};

                throw new IllegalArgumentException

                        (form.format(source) + ResourcesMgr.getString

                        ("Principal.Class.not.followed.by.a.Principal.Name"));

            }

            // skip delimiter

            tokenizer.nextToken();

            // get the Principal Name

            principalName = tokenizer.nextToken();

            if (!principalName.startsWith("\"")) {

                MessageFormat form = new MessageFormat(ResourcesMgr.getString

                        ("permission.name.name.syntax.invalid."));

                Object[] source = {name};

                throw new IllegalArgumentException

                        (form.format(source) + ResourcesMgr.getString

                        ("Principal.Name.must.be.surrounded.by.quotes"));

            }

            if (!principalName.endsWith("\"")) {

                // we have a name with spaces in it --

                // keep parsing until we find the end quote,

                // and keep the spaces in the name

                while (tokenizer.hasMoreTokens()) {

                    principalName = principalName + tokenizer.nextToken();

                    if (principalName.endsWith("\""))

                        break;

                }

                if (!principalName.endsWith("\"")) {

                    MessageFormat form = new MessageFormat

                        (ResourcesMgr.getString

                        ("permission.name.name.syntax.invalid."));

                    Object[] source = {name};

                    throw new IllegalArgumentException

                        (form.format(source) + ResourcesMgr.getString

                                ("Principal.Name.missing.end.quote"));

                }

            }

            if (testing)

                System.out.println("\tprincipalName = '" + principalName + "'");

            principalName = principalName.substring

                                        (1, principalName.length() - 1);

            if (principalClass.equals("*") &&

                !principalName.equals("*")) {

                    throw new IllegalArgumentException(ResourcesMgr.getString

                        ("PrivateCredentialPermission.Principal.Class.can.not.be.a.wildcard.value.if.Principal.Name.is.not.a.wildcard.value"));

            }

            if (testing)

                System.out.println("\tprincipalName = '" + principalName + "'");

            pList.add(new CredOwner(principalClass, principalName));

        }

        this.credOwners = new CredOwner[pList.size()];

        pList.toArray(this.credOwners);

    }

    private boolean impliesCredentialClass(String thisC, String thatC) {

        // this should never happen

        if (thisC == null || thatC == null)

            return false;

        if (testing)

            System.out.println("credential class comparison: " +

                                thisC + "/" + thatC);

        if (thisC.equals("*"))

            return true;

        /**

         * XXX let's not enable this for now --

         *      if people want it, we'll enable it later

         */

        /*

        if (thisC.endsWith("*")) {

            String cClass = thisC.substring(0, thisC.length() - 2);

            return thatC.startsWith(cClass);

        }

        */

        return thisC.equals(thatC);

    }

    private boolean impliesPrincipalSet(CredOwner[] thisP, CredOwner[] thatP) {

        // this should never happen

        if (thisP == null || thatP == null)

            return false;

        if (thatP.length == 0)

            return true;

        if (thisP.length == 0)

            return false;

        for (int i = 0; i < thisP.length; i++) {

            boolean foundMatch = false;

            for (int j = 0; j < thatP.length; j++) {

                if (thisP[i].implies(thatP[j])) {

                    foundMatch = true;

                    break;

                }

            }

            if (!foundMatch) {

                return false;

            }

        }

        return true;

    }

    /**

     * Reads this object from a stream (i.e., deserializes it)

     */

    @java.io.Serial

    private void readObject(java.io.ObjectInputStream s) throws

                                        java.io.IOException,

                                        ClassNotFoundException {

        s.defaultReadObject();

        // perform new initialization from the permission name

        if (getName().indexOf(' ') == -1 && getName().indexOf('"') == -1) {

            // name only has a credential class specified

            credentialClass = getName();

            credOwners = EMPTY_PRINCIPALS;

        } else {

            // perform regular initialization

            init(getName());

        }

    }

    /**

     * @serial include

     */

    static class CredOwner implements java.io.Serializable {

        @java.io.Serial

        private static final long serialVersionUID = -5607449830436408266L;

        /**

         * @serial

         */

        String principalClass;

        /**

         * @serial

         */

        String principalName;