On Thu, 13 Apr 2023 17:54:22 GMT, Weijun Wang <wei...@openjdk.org> wrote:
> Currently, `provider()` is a method of `KEM.Encapsulator`. If `KEMSpi.
> newEncapsulator` also returns this interface, then what value should its
> `provider()` method return? This is what I meant registering itself to a
> provider.
>
> When I said different instances, I was asking
>
> ```
> var k = KEM.getInstance("DHKEM", p);
> var e = k.newEncapsulator(pk);
> // now, is p == e.provider()?
> ```
>
> Or, are you suggesting we should define `provider()` somewhere else? It's
> possible, but I have difficulty making every class immutable.
If the provider() method in KEM.Encapsulator is the only reason, the cost to
support it may be too high with so many duplicated/similar specifications/names
and code.
Option 1: Remove the KEM.Encapsulator.provider() method, and provide no access
to the underlying provider object.
> do you expect it to return new SunJCE()? This means the p in
> getInstance("DHKEM", p) will be a different instance from the value returned
> by getProvider().
The Provider class is mutable, we may not want to change the provider object
asked for "DHKEM". I think you have used a solution to pass the provider
object in the KEM.java implementation currently. Maybe, it could be twitted a
little bit so that the provider can be passed to a delegated KM.Encapsulator
interface implementation.
Option 2:
public final class KEM {
interface Encapsulator {
...
KEM.Encapsulated encapsulate(...);
...
default Provider provider() {
return null;
}
}
private static class DelegatedEncapsulator implements Encapsulator {
private final Provider p;
private DelegatedEncapsulator(Encapsulator e, Provider p) {
this.p = p;
...
}
public Provider provider() {
return this.p;
}
}
...
KEMSpi spi = (KEMSpi) service.newInstance(null);
return new DelegatedEncapsulator(
spi.engineNewEncapsulator(pk, spec, secureRandom), //
This is the interface implementation, use the same provider as KEM.
service.getProvider()); // This is the provider passed to
the delegated KEM.Encapsulator object.
...
}
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/13256#discussion_r1165920458
