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 * access control {@code Policy}. * *
A {@code Policy} object can be queried for the set of * Permissions granted to code running as a * {@code Principal} in the following manner: * *
* policy = Policy.getPolicy(); * PermissionCollection perms = policy.getPermissions(subject, * codeSource); ** * The {@code Policy} object consults the local policy and returns * and appropriate {@code Permissions} object with the * Permissions granted to the Principals associated with the * provided {@code subject}, and granted to the code specified * by the provided {@code codeSource}. * *
A {@code Policy} contains the following information. * Note that this example only represents the syntax for the default * {@code Policy} implementation. Subclass implementations of this class * may implement alternative syntaxes and may retrieve the * {@code Policy} from any source such as files, databases, * or servers. * *
Each entry in the {@code Policy} is represented as * a grant entry. Each grant entry * specifies a codebase, code signers, and Principals triplet, * as well as the Permissions granted to that triplet. * *
* grant CodeBase ["URL"], Signedby ["signers"],
* Principal [Principal_Class] "Principal_Name" {
* Permission Permission_Class ["Target_Name"]
* [, "Permission_Actions"]
* [, signedBy "SignerName"];
* };
*
*
* The CodeBase and Signedby components of the triplet name/value pairs
* are optional. If they are not present, then any codebase will match,
* and any signer (including unsigned code) will match.
* For Example,
*
*
* grant CodeBase "foo.com", Signedby "foo",
* Principal com.sun.security.auth.SolarisPrincipal "duke" {
* permission java.io.FilePermission "/home/duke", "read, write";
* };
*
*
* This grant entry specifies that code from "foo.com",
* signed by "foo', and running as a {@code SolarisPrincipal} with the
* name, duke, has one {@code Permission}. This {@code Permission}
* permits the executing code to read and write files in the directory,
* "/home/duke".
*
* To "run" as a particular {@code Principal}, * code invokes the {@code Subject.doAs(subject, ...)} method. * After invoking that method, the code runs as all the Principals * associated with the specified {@code Subject}. * Note that this {@code Policy} (and the Permissions * granted in this {@code Policy}) only become effective * after the call to {@code Subject.doAs} has occurred. * *
Multiple Principals may be listed within one grant entry. * All the Principals in the grant entry must be associated with * the {@code Subject} provided to {@code Subject.doAs} * for that {@code Subject} to be granted the specified Permissions. * *
* 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";
* };
*
*
* 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".
*
* Note that non Principal-based grant entries are not permitted * in this {@code Policy}. Therefore, grant entries such as: * *
* grant CodeBase "foo.com", Signedby "foo" {
* permission java.io.FilePermission "/tmp/scratch", "read, write";
* };
*
*
* are rejected. Such permission must be listed in the
* {@code java.security.Policy}.
*
* 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: *
* public PermissionCollection getPermissions * (java.security.ProtectionDomain pd) * ** and ProtectionDomain has a constructor: *
* public ProtectionDomain * (CodeSource cs, * PermissionCollection permissions, * ClassLoader loader, * Principal[] principals) ** * These two APIs provide callers the means to query the * Policy for Principal-based Permission entries. * * @since 1.4 * @see java.security.Security security properties */ @Deprecated(since="1.4") public abstract class Policy { private static Policy policy; private static final String AUTH_POLICY = "sun.security.provider.AuthPolicyFile"; private final java.security.AccessControlContext acc = java.security.AccessController.getContext(); // true if a custom (not AUTH_POLICY) system-wide policy object is set private static boolean isCustomPolicy; /** * Sole constructor. (For invocation by subclass constructors, typically * implicit.) */ protected Policy() { } /** * Returns the installed Policy object. * This method first calls * {@code SecurityManager.checkPermission} with the * {@code AuthPermission("getPolicy")} permission * to ensure the caller has permission to get the Policy object. * * @return the installed Policy. The return value cannot be * {@code null}. * * @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 = AccessController.doPrivileged (new PrivilegedAction
This method causes this object to refresh/reload its current * Policy. This is implementation-dependent. * For example, if the Policy object is stored in * a file, calling {@code refresh} will cause the file to be re-read. * * @exception SecurityException if the caller does not have permission * to refresh the Policy. */ public abstract void refresh(); }