net.jini.core.constraint
Class Integrity

java.lang.Object
  net.jini.core.constraint.Integrity

All Implemented Interfaces:

Serializable, InvocationConstraint

public final class Integrity
extends Object
implements InvocationConstraint, Serializable

Represents a constraint on the integrity of message contents, covering not only data transmitted in band as part of the remote call itself, but also out-of-band downloaded code. If an integrity violation on in-band data is detected during a remote call, a RemoteException will be thrown (in the client or in the server, depending on which side detected the violation). If an integrity violation on out-of-band data is detected, an IOException will be thrown at the point where the data is downloaded.

Although most of the data for a remote call is transmitted in band as part of the call itself, code is downloaded out of band, based on codebase URLs that are transmitted in band. For a remote call to have integrity, the out-of-band code as well as the in-band data must have integrity. A proxy implementation that provides for integrity must ensure the integrity of both code and data.

Code signing is difficult to use for this purpose if the classes span more than a single package (because individual files are signed rather than the entire JAR file being signed, and the only automatic enforcement is that classes in a single package all have the same signers), or if the code references bundled resources (because there is no way to determine the signers of a resource). A better technique is to use codebase URLs that provide content integrity, such as HTTPMD or HTTPS URLs. If integrity-protecting codebase URLs are used, and the URLs themselves are sent as part of the integrity-protected in-band data, the result is complete object integrity. Because out-of-band communication is used, integrity-protecting URLs must either contain sufficient information to independently verify integrity (as is the case with HTTPMD URLs), or must contain sufficient information to authenticate the origin of the content and use sufficient means to maintain content integrity in transit (as is the case with HTTPS URLs).

Serialization for this class is guaranteed to produce instances that are comparable with ==.

Since:

2.0

Author:

Sun Microsystems, Inc.

See Also:

Security.verifyCodebaseIntegrity, Serialized Form

Field Summary

static Integrity	NO Do not detect when message contents have been altered by third parties.
static Integrity	YES Detect when message contents (both requests and replies) have been altered by third parties, and if detected, refuse to process the message and throw an exception.

Method Summary

String

toString() Returns a string representation of this object.

Methods inherited from class java.lang.Object

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

Field Detail

YES

public static final Integrity YES

Detect when message contents (both requests and replies) have been altered by third parties, and if detected, refuse to process the message and throw an exception. The mechanisms used to maintain integrity are not specified by this constraint.

NO

public static final Integrity NO

Do not detect when message contents have been altered by third parties. Normally this constraint should not be used, as many secure communication mechanisms have integrity mechanisms that cannot be disabled.

Method Detail

toString

public String toString()

Returns a string representation of this object.

Overrides:

toString in class Object