Module java.security.jgss
Package javax.security.auth.kerberos

# Class ServicePermission

java.lang.Object
java.security.Permission
javax.security.auth.kerberos.ServicePermission

All Implemented Interfaces:
  `Serializable`, `Guard`

public final class ServicePermission extends Permission implements Serializable
This class is used to protect Kerberos services and the credentials necessary to access those services. There is a one to one mapping of a service principal and the credentials necessary to access the service. Therefore, granting access to a service principal implicitly grants access to the credential necessary to establish a security context with the service principal. This applies regardless of whether the credentials are in a cache or acquired via an exchange with the KDC. The credential can be either a ticket granting ticket, a service ticket or a secret key from a key table.

A ServicePermission contains a service principal name and a list of actions which specify the context the credential can be used within.

The service principal name is the canonical name of the `KerberosPrincipal` supplying the service, that is the KerberosPrincipal represents a Kerberos service principal. This name is treated in a case sensitive manner. An asterisk may appear by itself, to signify any service principal.

Granting this permission implies that the caller can use a cached credential (TGT, service ticket or secret key) within the context designated by the action. In the case of the TGT, granting this permission also implies that the TGT can be obtained by an Authentication Service exchange.

Granting this permission also implies creating `KerberosPrincipal` or `GSSName` without providing a Kerberos realm, as long as the permission's service principal is in this realm.

The possible actions are:

        initiate -              allow the caller to use the credential to
                                initiate a security context with a service
                                principal.

        accept -                allow the caller to use the credential to
                                accept security context as a particular
                                principal.

For example, to specify the permission to access to the TGT to initiate a security context the permission is constructed as follows:

         ServicePermission("krbtgt/EXAMPLE.COM@EXAMPLE.COM", "initiate");

To obtain a service ticket to initiate a context with the "host" service the permission is constructed as follows:

         ServicePermission("host/foo.example.com@EXAMPLE.COM", "initiate");

For a Kerberized server the action is "accept". For example, the permission necessary to access and use the secret key of the Kerberized "host" service (telnet and the likes) would be constructed as follows:

         ServicePermission("host/foo.example.com@EXAMPLE.COM", "accept");

Since:
  1.4
See Also:
  - Serialized Form

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `ServicePermission(String servicePrincipal, String action)`
  Create a new `ServicePermission` with the specified `servicePrincipal` and `action`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `boolean`
  `equals(Object obj)`
  Checks two ServicePermission objects for equality.
  `String`
  `getActions()`
  Returns the canonical string representation of the actions.
  `int`
  `hashCode()`
  Returns the hash code value for this object.
  `boolean`
  `implies(Permission p)`
  Checks if this Kerberos service permission object "implies" the specified permission.
  `PermissionCollection`
  `newPermissionCollection()`
  Returns a PermissionCollection object for storing ServicePermission objects.

  ### Methods declared in class java.security.Permission

  `checkGuard, getName, toString`

  ### Methods declared in class java.lang.Object

  `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- ## Constructor Details

  - ### ServicePermission

    public ServicePermission(String servicePrincipal, String action)
    Create a new `ServicePermission` with the specified `servicePrincipal` and `action`.
    Parameters:
      `servicePrincipal` - the name of the service principal. An asterisk may appear by itself, to signify any service principal.
      `action` - the action string

- ## Method Details

  - ### implies

    public boolean implies(Permission p)
    Checks if this Kerberos service permission object "implies" the specified permission.

    More specifically, this method returns true if all the following are true (and returns false if any of them are not):

    - p is an instanceof `ServicePermission`,
    - p's actions are a proper subset of this `ServicePermission`'s actions,
    - p's name is equal to this `ServicePermission`'s name or this `ServicePermission`'s name is "*".
    Specified by:
      `implies` in class `Permission`
    Parameters:
      `p` - the permission to check against.
    Returns:
      true if the specified permission is implied by this object, false if not.

  - ### equals

    public boolean equals(Object obj)
    Checks two ServicePermission objects for equality.
    Specified by:
      `equals` in class `Permission`
    Parameters:
      `obj` - the object to test for equality with this object.
    Returns:
      true if `obj` is a ServicePermission, and has the same service principal, and actions as this ServicePermission object.
    See Also:
      - `Object.hashCode()`
      - `HashMap`

  - ### hashCode

    public int hashCode()
    Returns the hash code value for this object.
    Specified by:
      `hashCode` in class `Permission`
    Returns:
      a hash code value for this object.
    See Also:
      - `Object.equals(java.lang.Object)`
      - `System.identityHashCode(java.lang.Object)`

  - ### getActions

    public String getActions()
    Returns the canonical string representation of the actions. Always returns present actions in the following order: initiate, accept.
    Specified by:
      `getActions` in class `Permission`
    Returns:
      the actions of this `Permission`.

  - ### newPermissionCollection

    public PermissionCollection newPermissionCollection()
    Returns a PermissionCollection object for storing ServicePermission objects.
    ServicePermission objects must be stored in a manner that allows them to be inserted into the collection in any order, but that also enables the PermissionCollection implies method to be implemented in an efficient (and consistent) manner.
    Overrides:
      `newPermissionCollection` in class `Permission`
    Returns:
      a new PermissionCollection object suitable for storing ServicePermissions.