[External] : Authorization Layer post JEP 411

[Ron Pressler]

> On 3 Jun 2021, at 00:41, Peter Firmstone <peter.firmstone at zeus.net.au> wrote:
> 
> 

> StackWalker doesn't work with compiled code, only bytecode.

If you’re referring to GraalVM’s Native Image, I don’t know about that problem and
there does seem to be a relevant patch (https://github.com/oracle/graal/pull/734), but
Native Image is a separate project from OpenJDK.

> 
> AccessController and AccessControlContext allow backward compatiblity for JAAS.   JAAS whether we like it or not, is the default authorisation layer framework.
> 
> http://word-bits.flurg.com/jaas-is-terrible-and-there-is-no-escape-from-it/

I don’t know how much a seven-year-old article, that predates Java 8 supports the use
of the present tense, but in any event, the JEP says that JAAS will be preserved.

> 
> With SecurityManager gone, people will no longer assume it has sole responsible for Security

People don’t assume that now, as secure software doesn’t employ it even today. People do, 
however, assume that the mechanism, if used, is robust enough to be used for security 
purposes.

> OpenJDK devs won't carry a significant burden for it's maintenance.  

While the number of places where the JDK *implements* some “protected operation”, like
opening a file or writing to a socket, is somewhat bounded — and so keeping some hooks
in those places *might* be reasonable — the number of places that *use* those operations 
is not. Maintaining doPrivileged in that unbounded set of places is not an insignificant 
burden.


> Any security issues will be the responsibility of third party implementations, like mine.
> The JDK won't provide an implementation, just the framework.

But the correct use of doPrivileged, if you’re proposing that it’s kept, must still be
tested against *some* implementation, and OpenJDK would still need to fix bugs related
to it.

> 
> Those of us using the Principle of Least Privilege can continue to do so

Perhaps you believe that the only software in the world that applies Least Privilege is 
Java software that employs the Security Manager, but that is not how most people, including 
the person who had framed it two decades prior to the invention of the Security Manager, 
understand the principle.

The original statement of the principle was: "Every program and every privileged user of 
the system should operate using the least amount of privilege necessary to complete the 
job.” (https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.226.3939)

You are talking about applying the principle at a granularity of code units that are
smaller than a program. It’s fine to believe that is worthwhile, but the principle 
certainly doesn’t require that every effort be expended to afford least privilege at 
any granularity.

> and we can participate in OpenJDK to maintain Permission checks where we need them and preserve context where appropriate.

I think you’re underestimating the magnitude of this work, which potentially interacts with 
each and every change in the JDK (and in practice interacts with many of them, and today it’s
done by those who are responsible for the relevant change), which you’ll need to monitor, 
not to mention that OpenJDK Reviewers, a role granted only to the most experienced contributors, 
would still have to review that work.

However, if you think that is an amount of work you could manage, perhaps it could be done 
outside the JDK using Java Agents.

> 
> JAAS will continue to remain functional 

The JEP already intends to keep JAAS functional, as far as I can tell.

— Ron