Defines a remote interface for obtaining a proxy trust verifier.
Defines an iterator that produces objects from which a
Defines a local interface to obtain a proxy trust verifier.
Defines an interface for checking that an object (that is not yet known to be trusted) is equivalent in trust, content, and function to a known trusted object.
A trust verifier context element that provides a security context to use to restrict privileges when invoking methods on untrusted objects.
A basic trust verifier context element that provides a security context to use to restrict privileges when invoking methods on untrusted objects, based on a specified set of permissions.
Contains the information necessary to export a remote object that has a proxy that will not directly be considered trusted by clients, such that the proxy can be trusted by clients using
Invocation handler for remote objects, supporting proxy trust verification by clients using
Trust verifier for service proxies that use dynamically downloaded code.
The purpose of this package is to support verification of proxies that use dynamically downloaded code, in a way that limits the knowledge that must be pre-configured into the client. Specifically, the idea is to require the client to only know who the server must authenticate as (which is something the client presumably needs to know anyway), to avoid requiring the client to know anything else (such as where the code was downloaded from or who signed that code), and to avoid making assumptions about the authentication mechanism (such as requiring the server to have a public/private key pair that it has to use for signing the proxy code).
Rather than having the client directly determine if it trusts the proxy, the approach taken is to first determine that the client can trust the server (by requiring the server to authenticate itself), and then determine that the server trusts the proxy (by asking the server for a verifier and passing the proxy to that verifier). If the client trusts the server and the server trusts the proxy, then transitively the client is inferred to trust the proxy. However, there are questions to answer for both of these steps.
First, there is the question of how the client can reliably verify that the
server authenticates itself, when the client does not yet trust the
downloaded proxy. The
requires the proxy to support some bootstrap remote communication mechanism
that the client does trust. Specifically, the proxy must be able to provide a
bootstrap proxy, which must be an instance of both
bootstrap proxy either must be trusted by the client, or it must be a
dynamic proxy which is trusted by the client after removing remote codebase
information from the dynamic proxy class. In the common case of a smart
proxy wrapped around a standard dynamic proxy (for example, a dynamic proxy
for a remote object exported to use Jini extensible remote invocation
(Jini ERI)), the dynamic proxy usually can serve as the bootstrap proxy if
its invocation handler does not depend on any downloaded code, on the
assumption that the client will have configured in a trust verifier for local
dynamic proxies and their invocation handlers (for example,
BasicJeriTrustVerifier). However, there
is no requirement that normal communication with the server use the same
protocol used by the bootstrap proxy; the bootstrap proxy could be used
strictly for trust verification. The
is provided for this purpose.
Second, there is the question of how to reliably obtain a verifier from the
server. (The proxy is not sent to the server because an untrusted proxy
could use a
writeReplace serialization method to replace
itself on the wire with a trusted proxy; the proxy needs to be checked in
the client.) Authentication of the server should be required during the
remote call through the bootstrap proxy to obtain the verifier from the
server, as should object integrity, so that the remote call and the
verifier object received from it can be trusted. To accomplish this,
the client is responsible for specifying
ServerAuthentication.YES, an appropriate
as requirements for the
ProxyTrust.getProxyVerifier method in a
included as an element of the context collection passed to
Security.verifyObjectTrust. Normally such constraints should be
obtained from a
than being explicitly constructed.