java.rmi.constraint
Class ServerMinPrincipal

java.lang.Object
  |
  +--java.rmi.constraint.ServerMinPrincipal
All Implemented Interfaces:
SecurityConstraint, java.io.Serializable

public final class ServerMinPrincipal
extends java.lang.Object
implements SecurityConstraint, java.io.Serializable

Represents a constraint on the server, such that if the server authenticates itself, then it must authenticate itself as at least all of the specified principals.

The use of an instance of this constraint does not imply directly a ServerAuthentication.YES constraint; that must be specified separately to ensure that the server actually authenticates itself.

It is important to understand that specifying ServerAuthentication.YES as a requirement does not ensure that a server is to be trusted; it does ensure that the server authenticates itself as someone, but it does not ensure that the server authenticates itself as anyone in particular. Without knowing who the server authenticated itself as, there is no basis for actually trusting the server. The client generally needs to specify a ServerMinPrincipal requirement in addition, or else verify that the server has specified a satisfactory ServerMinPrincipal requirement for each of the methods that the client cares about.

Since:
1.4
See Also:
AuthenticationPermission, Serialized Form

Constructor Summary
ServerMinPrincipal(java.util.Collection c)
          Returns a constraint containing the specified principals, with duplicates removed.
ServerMinPrincipal(java.security.Principal p)
          Returns a constraint containing the specified principal.
ServerMinPrincipal(java.security.Principal[] principals)
          Returns a constraint containing the specified principals, with duplicates removed.
 
Method Summary
 java.util.Set elements()
          Returns an immutable set of all the principals.
 boolean equals(java.lang.Object obj)
          Two instances of this class are equal if they have the same principals (ignoring order).
 int hashCode()
          Returns a hash code value for this object.
 SecurityConstraint reduceBy(SecurityConstraint c)
          Returns the smallest representable subset of this constraint that contains the intersection of this constraint with the specified constraint, or null if there is no intersection.
 java.lang.String toString()
          Returns a string representation of this object.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

ServerMinPrincipal

public ServerMinPrincipal(java.security.Principal p)
Returns a constraint containing the specified principal. This constructor is equivalent to calling a constructor with a single-element array containing the specified principal.
Parameters:
p - the principal
Throws:
NullPointerException - if the parameter is null
java.lang.IllegalArgumentException - if the parameter is not an instance of a trusted principal class

ServerMinPrincipal

public ServerMinPrincipal(java.security.Principal[] principals)
Returns a constraint containing the specified principals, with duplicates removed. The parameter passed to the constructor is neither modified nor retained; subsequent changes to that parameter have no effect on the instance created.
Parameters:
principals - the principals
Throws:
NullPointerException - if the parameter is null or any element is null
java.lang.IllegalArgumentException - if the parameter is empty or the elements are not all instances of trusted principal classes

ServerMinPrincipal

public ServerMinPrincipal(java.util.Collection c)
Returns a constraint containing the specified principals, with duplicates removed. The parameter passed to the constructor is neither modified nor retained; subsequent changes to that parameter have no effect on the instance created.
Parameters:
c - the principals
Throws:
NullPointerException - if the parameter is null or any element is null
java.lang.IllegalArgumentException - if the parameter is empty or the elements are not all instances of trusted principal classes
Method Detail

elements

public java.util.Set elements()
Returns an immutable set of all the principals. Any attempt to modify the set results in an UnsupportedOperationException being thrown.
Returns:
an immutable set of all of the principals

reduceBy

public SecurityConstraint reduceBy(SecurityConstraint c)
Returns the smallest representable subset of this constraint that contains the intersection of this constraint with the specified constraint, or null if there is no intersection.

For any instances c1 and c2 of this class, c1.reduceBy(c2) returns a ServerMinPrincipal constructed from the combined principals of both c1 and c2, with duplicate principals removed.

For any instance c of this class, c.reduceBy(ServerAuthentication.NO) returns ServerAuthentication.NO.

For any instance c1 of this class and any ConstraintAlternatives instance c2 containing ServerMinPrincipal instances, c1.reduceBy(c2) returns the result of calling ConstraintAlternatives.create with all of the values returned by c1.reduceBy(c) for each element c of c2.

For any instance c1 of this class and any other constraint instance c2 no previously mentioned, c1.reduceBy(c2) returns c1.

Specified by:
reduceBy in interface SecurityConstraint
Following copied from interface: java.rmi.constraint.SecurityConstraint
Parameters:
c - a constraint
Returns:
the smallest representable subset of this constraint that intersects with the specified constraint, or null if there is no intersection

hashCode

public int hashCode()
Returns a hash code value for this object.
Overrides:
hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)
Two instances of this class are equal if they have the same principals (ignoring order).
Overrides:
equals in class java.lang.Object

toString

public java.lang.String toString()
Returns a string representation of this object.
Overrides:
toString in class java.lang.Object


Copyright © 2000 Sun Microsystems, Inc. All rights reserved