com.ibm.security.auth
Class PolicyFile

java.lang.Object
  |
  +--javax.security.auth.Policy
        |
        +--com.ibm.security.auth.PolicyFile

public class PolicyFile

extends Policy

This class represents a default implementation for javax.security.auth.Policy.

This object stores the policy for entire Java runtime, and is the amalgamation of multiple static policy configurations that resides in files. The algorithm for locating the policy file(s) and reading their information into this Policy object is:

1. Loop through the java.security.Security properties, auth.policy.url.1, auth.policy.url.2, ..., auth.policy.url.X". These properties are set in the Java security properties file, which is located in the file named <JAVA_HOME>/lib/security/java.security, where <JAVA_HOME> refers to the directory where the JDK was installed. Each property value specifies a URL pointing to a policy file to be loaded. Read in and load each policy.
2. The java.lang.System property java.security.auth.policy may also be set to a URL pointing to another policy file (which is the case when a user uses the -D switch at runtime). If this property is defined, and its use is allowed by the security property file (the Security property, policy.allowSystemProperty is set to true), also load that policy.
3. If the java.security.auth.policy property is defined using "==" (rather than "="), then ignore all other specified policies and only load this policy.

Each policy file consists of one or more grant entries, each of which consists of a number of permission entries.

   grant signedBy "alias", codeBase "URL",
         principal principalClass "principalName",
         principal principalClass "principalName",
         ... {

     permission Type "name "action",
         signedBy "alias";
     permission Type "name "action",
         signedBy "alias";
     ....
   };
 

All non-bold items above must appear as is (although case doesn't matter and some are optional, as noted below). Italicized items represent variable values.

A grant entry must begin with the word grant. The signedBy and codeBase name/value pairs are optional. If they are not present, then any signer (including unsigned code) will match, and any codeBase will match. Note that the principal name/value pair is not optional. This Policy implementation only permits Principal-based grant entries. Note that the principalClass may be set to the wildcard value, *, which allows it to match any Principal class. In addition, the principalName may also be set to the wildcard value, *, allowing it to match any Principal name. When setting the principalName to the *, do not surround the * with quotes.

A permission entry must begin with the word permission. The word Type in the template above is a specific permission type, such as java.io.FilePermission or java.lang.RuntimePermission.

The "action" is required for many permission types, such as java.io.FilePermission (where it specifies what type of file access that is permitted). It is not required for categories such as java.lang.RuntimePermission where it is not necessary - you either have the permission specified by the "name" value following the type name or you don't.

The signedBy name/value pair for a permission entry is optional. If present, it indicates a signed permission. That is, the permission class itself must be signed by the given alias in order for it to be granted. For example, suppose you have the following grant entry:

   grant principal foo.com.Principal "Duke" {
     permission Foo "foobar", signedBy "FooSoft";
   }
 

Then this permission of type Foo is granted if the Foo.class permission has been signed by the "FooSoft" alias, or if Foo.class is a system class (i.e., is found on the CLASSPATH).

Items that appear in an entry must appear in the specified order (permission, Type, "name", and "action"). An entry is terminated with a semicolon.

Case is unimportant for the identifiers (permission, signedBy, codeBase, etc.) but is significant for the Type or for any string that is passed in as a value.

An example of two entries in a policy configuration file is

   // if the code is comes from "foo.com" and is running as "Duke",
   // grant it read/write to all files in /tmp.

   grant codeBase "foo.com", principal foo.com.Principal "Duke" {
      permission java.io.FilePermission "/tmp/*", "read,write";
   };

   // grant any code running as "Duke" permission to read
   // the "java.vendor" Property.

   grant principal foo.com.Principal "Duke" {
     permission java.util.PropertyPermission "java.vendor";
 

This Policy implementation supports special handling for PrivateCredentialPermissions. If a grant entry is configured with a PrivateCredentialPermission, and the "Principal Class/Principal Name" for that PrivateCredentialPermission is "self", then the entry grants the specified Subject permission to access its own private Credential. For example, the following grants the Subject "Duke" access to its own a.b.Credential.

   grant principal foo.com.Principal "Duke" {
  permission javax.security.auth.PrivateCredentialPermission
      "a.b.Credential self",
      "read";
    };
 

The following grants the Subject "Duke" access to all of its own private Credentials:

   grant principal foo.com.Principal "Duke" {
  permission javax.security.auth.PrivateCredentialPermission
      "* self",
      "read";
    };
 

The following grants all Subjects authenticated as an AIXPrincipal (regardless of their respective names) permission to access their own private Credentials:

   grant principal com.ibm.security.auth.AIXPrincipal * {
  permission javax.security.auth.PrivateCredentialPermission
      "* self",
      "read";
    };
 

The following grants all Subjects permission to access their own private Credentials:

   grant principal * * {
  permission javax.security.auth.PrivateCredentialPermission
      "* self",
      "read";
    };
 

Version:

1.22, 01/25/00

See Also:

CodeSource, Permissions, ProtectionDomain

Constructor Summary

PolicyFile()
Initializes the Policy object and reads the default policy configuration file(s) into the Policy object.

Method Summary

java.security.PermissionCollection	getPermissions(Subject subject, java.security.CodeSource codesource) Examines this Policy and returns the Permissions granted to the specified Subject and CodeSource.
void	refresh() Refreshes the policy object by re-reading all the policy files.

Methods inherited from class javax.security.auth.Policy

getPolicy, setPolicy

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PolicyFile

public PolicyFile()

Initializes the Policy object and reads the default policy configuration file(s) into the Policy object.

Method Detail

refresh

public void refresh()

Refreshes the policy object by re-reading all the policy files.

Overrides:

refresh in class Policy

Throws:

java.lang.SecurityException - if the caller doesn't have permission to refresh the Policy.

getPermissions

public java.security.PermissionCollection getPermissions(Subject subject,
                                                         java.security.CodeSource codesource)

Examines this Policy and returns the Permissions granted to the specified Subject and CodeSource.

Permissions for a particular grant entry are returned if the CodeSource constructed using the codebase and signedby values specified in the entry implies the CodeSource provided to this method, and if the Subject provided to this method contains all of the Principals specified in the entry.

The Subject provided to this method contains all of the Principals specified in the entry if, for each Principal, "P1", specified in the grant entry one of the following two conditions is met:

1. the Subject has a Principal, "P2", where P2.getClass().getName() equals the P1's class name, and where P2.getName() equals the P1's name.
2. P1 implements com.ibm.security.auth.PrincipalComparator, and P1.implies the provided Subject.

Note that this Policy implementation has special handling for PrivateCredentialPermissions. When this method encounters a PrivateCredentialPermission which specifies "self" as the Principal class and name, it does not add that Permission to the returned PermissionCollection. Instead, it builds a new PrivateCredentialPermission for each Principal associated with the provided Subject. Each new PrivateCredentialPermission contains the same Credential class as specified in the originally granted permission, as well as the Class and name for the respective Principal.

Overrides:

getPermissions in class Policy

Parameters:

subject - the Permissions granted to this Subject and the additionally provided CodeSource are returned.

codesource - the Permissions granted to this CodeSource and the additionally provided Subject are returned.

Returns:

the Permissions granted to the provided Subject CodeSource.