/*

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.security.auth;

import java.security.Security;

import sun.security.util.Debug;

/**

 * <p> This is an abstract class for representing the system policy for

 * Subject-based authorization.  A subclass implementation

 * of this class provides a means to specify a Subject-based

 *

 * Permissions granted to code running as a

 *

 * <pre>

 *      policy = Policy.getPolicy();

 *      PermissionCollection perms = policy.getPermissions(subject,

 *                                                      codeSource);

 * </pre>

 *

 * Permissions granted to the Principals associated with the

 * provided <i>subject</i>, and granted to the code specified

 * by the provided <i>codeSource</i>.

 *

 * Note that this example only represents the syntax for the default

 * may implement alternative syntaxes and may retrieve the

 * or servers.

 *

 * a <b><i>grant</i></b> entry.  Each <b><i>grant</i></b> entry

 * specifies a codebase, code signers, and Principals triplet,

 * as well as the Permissions granted to that triplet.

 *

 * <pre>

 *      grant CodeBase ["URL"], Signedby ["signers"],

 *            Principal [Principal_Class] "Principal_Name" {

 *          Permission Permission_Class ["Target_Name"]

 *                                      [, "Permission_Actions"]

 *                                      [, signedBy "SignerName"];

 *      };

 * </pre>

 *

 * The CodeBase and Signedby components of the triplet name/value pairs

 * are optional.  If they are not present, then any any codebase will match,

 * and any signer (including unsigned code) will match.

 * For Example,

 *

 * <pre>

 *      grant CodeBase "foo.com", Signedby "foo",

 *            Principal com.sun.security.auth.SolarisPrincipal "duke" {

 *          permission java.io.FilePermission "/home/duke", "read, write";

 *      };

 * </pre>

 *

 * This <b><i>grant</i></b> entry specifies that code from "foo.com",

 * permits the executing code to read and write files in the directory,

 * "/home/duke".

 *

 * After invoking that method, the code runs as all the Principals

 *

 * <p> Multiple Principals may be listed within one <b><i>grant</i></b> entry.

 * All the Principals in the grant entry must be associated with

 *

 * <pre>

 *      grant Principal com.sun.security.auth.SolarisPrincipal "duke",

 *            Principal com.sun.security.auth.SolarisNumericUserPrincipal "0" {

 *          permission java.io.FilePermission "/home/duke", "read, write";

 *          permission java.net.SocketPermission "duke.com", "connect";

 *      };

 * </pre>

 *

 * This entry grants any code running as both "duke" and "0"

 * permission to read and write files in duke's home directory,

 * as well as permission to make socket connections to "duke.com".

 *

 * <p> Note that non Principal-based grant entries are not permitted

 *

 * <pre>

 *      grant CodeBase "foo.com", Signedby "foo" {

 *          permission java.io.FilePermission "/tmp/scratch", "read, write";

 *      };

 * </pre>

 *

 * are rejected.  Such permission must be listed in the

 *

 * <p> The default {@code Policy} implementation can be changed by

 * setting the value of the {@code auth.policy.provider} security property to

 * the fully qualified name of the desired {@code Policy} implementation class.

 *

 * @deprecated  as of JDK version 1.4 -- Replaced by java.security.Policy.

 *              java.security.Policy has a method:

 * <pre>

 *      public PermissionCollection getPermissions

 *          (java.security.ProtectionDomain pd)

 *

 * </pre>

 * and ProtectionDomain has a constructor:

 * <pre>

 *      public ProtectionDomain

 *          (CodeSource cs,

 *           PermissionCollection permissions,

 *           ClassLoader loader,

 *           Principal[] principals)

 * </pre>

 *

 * These two APIs provide callers the means to query the

 * Policy for Principal-based Permission entries.

 *

 * @see java.security.Security security properties

 */

@Deprecated

public abstract class Policy {

    private static Policy policy;

    private static ClassLoader contextClassLoader;

    // true if a custom (not com.sun.security.auth.PolicyFile) system-wide

    // policy object is set

    private static boolean isCustomPolicy;

    static {

        contextClassLoader = java.security.AccessController.doPrivileged

                (new java.security.PrivilegedAction<ClassLoader>() {

                public ClassLoader run() {

                    return Thread.currentThread().getContextClassLoader();

                }

        });

    };

    /**

     * Sole constructor.  (For invocation by subclass constructors, typically

     * implicit.)

     */

    protected Policy() { }

    /**

     * Returns the installed Policy object.

     * This method first calls

     * to ensure the caller has permission to get the Policy object.

     *

     * <p>

     *

     * @return the installed Policy.  The return value cannot be

     *

     * @exception java.lang.SecurityException if the current thread does not

     *      have permission to get the Policy object.

     *

     * @see #setPolicy

     */

    public static Policy getPolicy() {

        java.lang.SecurityManager sm = System.getSecurityManager();

        if (sm != null) sm.checkPermission(new AuthPermission("getPolicy"));

        return getPolicyNoCheck();

    }

    /**

     * Returns the installed Policy object, skipping the security check.

     *

     * @return the installed Policy.

     *

     */

    static Policy getPolicyNoCheck() {

        if (policy == null) {

            synchronized(Policy.class) {

                if (policy == null) {

                    String policy_class = null;

                    policy_class = java.security.AccessController.doPrivileged

                        (new java.security.PrivilegedAction<String>() {

                        public String run() {

                            return java.security.Security.getProperty

                                ("auth.policy.provider");

                        }

                    });

                    if (policy_class == null) {

                        policy_class = "com.sun.security.auth.PolicyFile";

                    }

                    try {

                        final String finalClass = policy_class;

                        policy = java.security.AccessController.doPrivileged

                            (new java.security.PrivilegedExceptionAction<Policy>() {

                            public Policy run() throws ClassNotFoundException,

                                                InstantiationException,

                                                IllegalAccessException {

                                return (Policy) Class.forName

                                        (finalClass,

                                        true,

                                        contextClassLoader).newInstance();

                            }

                        });

                        isCustomPolicy =

                            !finalClass.equals("com.sun.security.auth.PolicyFile");

                    } catch (Exception e) {

                        throw new SecurityException

                                (sun.security.util.ResourcesMgr.getString

                                ("unable.to.instantiate.Subject.based.policy"));

                    }

                }

            }

        }

        return policy;

    }

    /**

     * Sets the system-wide Policy object. This method first calls

     * permission to ensure the caller has permission to set the Policy.

     *

     * <p>

     *

     * @param policy the new system Policy object.

     *

     * @exception java.lang.SecurityException if the current thread does not

     *          have permission to set the Policy.

     *

     * @see #getPolicy

     */

    public static void setPolicy(Policy policy) {

        java.lang.SecurityManager sm = System.getSecurityManager();

        if (sm != null) sm.checkPermission(new AuthPermission("setPolicy"));

        Policy.policy = policy;

        // all non-null policy objects are assumed to be custom

        isCustomPolicy = policy != null ? true : false;

    }

    /**

     * Returns true if a custom (not com.sun.security.auth.PolicyFile)

     * system-wide policy object has been set or installed. This method is

     * called by SubjectDomainCombiner to provide backwards compatibility for

     * developers that provide their own javax.security.auth.Policy

     * implementations.

     *

     * @return true if a custom (not com.sun.security.auth.PolicyFile)

     * system-wide policy object has been set; false otherwise

     */

    static boolean isCustomPolicySet(Debug debug) {

        if (policy != null) {

            if (debug != null && isCustomPolicy) {

                debug.println("Providing backwards compatibility for " +

                              "javax.security.auth.policy implementation: " +

                              policy.toString());

            }

            return isCustomPolicy;

        }

        // check if custom policy has been set using auth.policy.provider prop

        String policyClass = java.security.AccessController.doPrivileged

            (new java.security.PrivilegedAction<String>() {

                public String run() {

                    return Security.getProperty("auth.policy.provider");

                }

        });

        if (policyClass != null

            && !policyClass.equals("com.sun.security.auth.PolicyFile")) {

            if (debug != null) {

                debug.println("Providing backwards compatibility for " +

                              "javax.security.auth.policy implementation: " +

                              policyClass);

            }

            return true;

        }

        return false;

    }

    /**

     * Retrieve the Permissions granted to the Principals associated with

     *

     * <p>

     *

     *                  whose associated Principals,

     *                  in conjunction with the provided

     *                  returned by this method.  This parameter

     *

     *                  that determines, in conjunction with the provided

     *                  returned by this method.  This parameter may be

     *

     * @return the Collection of Permissions granted to all the

     *                  the provided <i>subject</i> and <i>cs</i>

     *                  parameters.

     */

    public abstract java.security.PermissionCollection getPermissions

                                        (Subject subject,

                                        java.security.CodeSource cs);

    /**

     * Refresh and reload the Policy.

     *

     * <p>This method causes this object to refresh/reload its current

     * Policy. This is implementation-dependent.

     * For example, if the Policy object is stored in

     *

     * <p>

     *

     * @exception SecurityException if the caller does not have permission

     *                          to refresh the Policy.

     */

    public abstract void refresh();

}