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<p>One more proposed change inline:<br>
</p>
<div class="moz-cite-prefix">On 26/06/2021 12:58 pm, Peter Firmstone
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:9084f553-7440-de48-2e03-2447ebd280c5@zeus.net.au">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p>Summary of Proposed Changes:</p>
<ol>
<li>GuardFactory & GuardFactorySpi to provide hooks for
authorization checks without SecurityManager or Policy. (Note
GuardFactory should never return null and instead return a
no-op Guard that hotspot can optimize out.<br>
</li>
<li>Existing Permission implementations to be obtained using
GuardFactorySpi implementations, until their removal. Note
that when SecurityManager is stubbed out and Permission
implementations are deprecated for removal, these should no
longer be provided by default, but instead need to be enabled
by entries in the java.security config file, in preparation
for their removal.<br>
</li>
<li>JDK code, no longer call Permission implementations
directly, instances obtained using GuardFactory, only when
enabled in the java.security configuration file.<br>
</li>
<li>Threads (system and virtual) updated to use a singleton
*unprivileged* AccessControlContext, instead of inherited
AccessControlContext, this is more appropriate for Executors,
the original inherited context was designed before Executors
were introduced.</li>
<li>Deprecation for removal of all Permission implementations
from the JDK platform. The existing implementations of
Permission introduce unnecessary complexity; they lack
sufficient flexibility resulting in a proliferation of
Permission grants required in policy files and some make
blocking network calls.<br>
</li>
<li>Introduce a system property to change AccessController
default behaviour, disable the stack walk by default, but
allow it to be re-enabled with a system property, replace the
stack walk array result of ProtectionDomains with an
*unprivileged* AccessControlContext, the SubjectDomainCombiner
can replace it with a, AccessControlContext containing a
single element array, containing one ProtectionDomain with
Principals. <br>
</li>
<li>AccessController::doPrivileged erases the DomainCombiner by
default, deprecate these methods, retain
doPrivilegedWithCombiner methods that preserve the
SubjectDomainCombiner. Developers should replace their
doPrivileged methods with doPrivilegedWithCombiner</li>
<li>Deprecate for removal the CodeSource::implies method.</li>
<li>Give unique ProtectionDomain's with a meaninful CodeSource
to Java modules mapped to the boot loader, rather than using a
Shared ProtectionDomain with a null CodeSource.<br>
</li>
</ol>
</blockquote>
<p> 10. Deprecate for removal AccessController::checkPermission
and AccessControlContext::checkPermission methods.</p>
<p> 11. Undeprecate AccessController, AccessControlContext,
DomainCombiner, SubjectDomainCombiner and Subject::doAs methods,
while deprecating for removal methods stated in items above.<br>
</p>
<blockquote type="cite"
cite="mid:9084f553-7440-de48-2e03-2447ebd280c5@zeus.net.au">
<p>To clarify what an *unprivileged* AccessControlContext is:</p>
<blockquote>
<p>An instance of AccessControlContext, that contains a single
element array, containing a ProtectionDomain, with a non null
CodeSource, containing a null URL.</p>
</blockquote>
<p>Retention of AccessController, AccessControlContext,
DomainCombiner and SubjectDomainCombiner and Subject::doAs
methods.</p>
<p>Stubbing of SecurityManager and Policy, for runtime backward
compatibility. Update ProtectionDomain::implies method, to *not*
consult with the Policy. Note it's possible to get access to
the ProtectionDomain array contained within AccessControlContext
using a DomainCombiner.<br>
</p>
<p>This is backward compatible with existing usages of JAAS and
least painful method of transition for all concerned as well as
allowing complete flexibility of implementation.</p>
<p>Regards,</p>
<p>Peter Firmstone.<br>
</p>
<div class="moz-cite-prefix">On 25/06/2021 3:59 pm, Peter
Firmstone wrote:<br>
</div>
<blockquote type="cite"
cite="mid:2f315680-1cdb-1694-34a3-95312bf42ca7@zeus.net.au">Thanks
Dalibor, <br>
<br>
Would targeting Java 18 be practical? <br>
<br>
Also it won't take long to code a prototype, just not sure of
the process. <br>
<br>
Cheers, <br>
<br>
Peter. <br>
<br>
<br>
On 24/06/2021 9:30 pm, Dalibor Topic wrote: <br>
<blockquote type="cite">On 24.06.2021 04:24, Peter Firmstone
wrote: <br>
<blockquote type="cite">Thanks Andrew, <br>
<br>
For the simple case, of replacing the SecurityManager stack
walk, one could use reflection. <br>
<br>
Thank you for also confirming that is not possible (or at
least very unlikely) to add a GuardBuilder to Java 8, the
proposal is for JDK code to use a provider mechanism, to
intercept permission checks, so custom authentication layers
can be implemented, this could be accepted in future
versions of Java, but not existing. As it is said, there is
no harm in asking. <br>
</blockquote>
<br>
Generally speaking, adding any public APIs to a platform
release after its specification has been published, is always
going to be a very tall order involving the JCP, among other
things. It's not really worth it, when other technical
solutions, such as multi-release JARs, already exist, that
alleviate the necessity. <br>
<br>
cheers, <br>
dalibor topic <br>
<br>
</blockquote>
</blockquote>
</blockquote>
<pre class="moz-signature" cols="72">--
Regards,
Peter Firmstone
0498 286 363
Zeus Project Services Pty Ltd.</pre>
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