users@jacc-spec.java.net

Re: Ability to register JACC providers from web modules

From: Guillermo González de Agüero <z06.guillermo_at_gmail.com>
Date: Tue, 12 Jul 2016 20:46:21 +0200

On Tue, Jul 12, 2016 at 4:39 PM, Ron Monzillo <ron.monzillo_at_oracle.com>
wrote:

> On 7/12/16 10:09 AM, arjan tijms wrote:
>
> Hi,
>
> On Tue, Jul 12, 2016 at 3:52 PM, Ron Monzillo <ron.monzillo_at_oracle.com>
> wrote:
>
>> For example, I would think that this same problem applies
>> to the placement of a ServetContextInitializer; maybe we can learn from
>> how that is done, or
>> maybe there is a common problem that needs to be resolved.
>>
>
> Sorry, I meant ServletContainerInitializer, and my point was that
> containers "appear" to also be required to support
> the loading of an Initializer that is not bundled in a JAR file inside the
> WEB-INF/lib directory of an application, and that
> will be applied to all apps. which I think presents the same problem as
> we are facing with the placement and
> loading of a jacc provider.
>
But that kind of libraries are loaded in the same fashion as other user
provided libraries, as far as I know. Taking JSF as an example, JBoss
provides Mojarra implementation it as a *private* module. That means
classes are not exposed to application code.
In the case on Payara/GlassFish, server libraries are OSGI bundles, where
exported classes are defined in MANIFEST.MF. I suppose they have access to
the whole application classloader, but applications only have access to
exported classes.

I'll check the Platform Spec and I'll write to the spec ML in needed, but I
think this problem is solved in a propietary way, and I don't see it as a
problem for us anyway, provided we are flexible enough in our wording.

A ServetContextInitializer can conveniently be loaded from a .jar inside
> WEB-INF/lib of a .war, so that's perhaps a bit of a different situation. It
> uses the jar service loader mechanism if I'm not mistaken.
>
>
>
>> Regarding programmatic configuration of web security constraints, are you
>> aware of
>>
>> https://docs.oracle.com/javaee/7/api/javax/servlet/ServletRegistration.Dynamic.html#setServletSecurity-javax.servlet.ServletSecurityElement
>> -
>>
>> You should b able to programmatically define security constraints during
>> the initialization of a web application.
>> Its been some time since I tried this sort of thing, but you should be
>> able to do this from a ServletContainerListener.
>>
>
> Maybe I'm totally mistaken, but I thought that one only applied to
> Servlets that have been dynamically added to begin with, not for Servlets
> that were already statically defined (e.g. in web.xml or using the
> @WebServlet annotation). I could be wrong here though. Guillermo, I seem to
> remember you tried somewhere there, was it that method?
>
>
Exactly as Arjan said. ServletContainerInitializer and
ServletContextListener shares the same limitations:
- Security contraints can only be added to dyamically created Servlets.
- Contraints are applied on a per-Servlet basis, so specific URLs can't be
specified.

I commented by findings on SERVLET_SPEC-157 [1]. Anyway, Servlet should
provide a better solution than "use JACC for that", since Servlet doesn't
require JACC.

>
> yes, I guess that limits its applicability in your use case.
>
> fwiw, you *may/should* be able to call the jacc PolicyConfiguration api
> from your context listener; although
>
> 1. the api does not provide routines to let you see what constraints have
> already been defined in
> a PolicyContext
>
> 2. the spec should probably explicitly define that you can do this, and
> prescribe what calls can and must be made.
>

So there's already a way to define permissions from there? Could you please
provide some simple example code or a reference to where I could document
myself? That'd be very useful.

>
> Ron
>
>
> Kind regards,
> Arjan Tijms
>
>
>
>> You can see some mention of this in the JACC spec.
>>
>> Ron
>>
>>
>>
>> On 7/12/16 9:01 AM, Guillermo González de Agüero wrote:
>>
>> Hi,
>>
>> Modern Application Servers use complex class loading mechanism so I don't
>> think the situation can be simplified to defining a custom path. Doing that
>> implies that all required classes are available in the classpath and
>> probably that all the internal classes of the JAR are also exposed to
>> deployed applications.
>>
>> After seeing JBoss[1] and GlassFish/Payara[2] registration methods, I
>> propose something along these lines: "the Application Server MUST support a
>> system property named XX, which specifies the JAR/module/whatever term the
>> server uses, from which the classes are to be loaded. The Application
>> Server can opt to ignore this value ONLY if location can be unambiguously
>> determined (e.g. it uses a flat class loader)".
>>
>> Not the more end developer friendly solution for the problem, but maybe
>> that's as far as we can get now. It wouldn't interfere in implementors
>> class loading mechanisms, while still the user would get a clearer way to
>> install it.
>>
>> Regarding use cases: what I was originally trying to achieve was to
>> dynamically define security constraints[3] from a Web Application. As it is
>> now, the only way to do that is to install a custom JACC Provider. Yet it
>> comes with the price that you have to reimplement all the server's provider
>> logic, but it's the only option I found.
>>
>> If deploying custom per application providers doesn't fill in the Java
>> Security Model, or if there's simply not the needed quorum to make that
>> kind of decisions, what I think we could do is:
>> - Mandate a new property to specificy where to load the classes from,
>> leaving thecnical details to implementors (thus not requiring a specific
>> folder/path to be created).
>> - Provide some hooks for dynamic configuration: something like
>> add/removePermission(WebRoleRefPermission), getAllRoles(Subject), etc.
>> - Provide a base implementation that users can use. Arjan's example
>> implementation would be a good starting point.
>> - Standarize caller/principal and role/principal anrepresentation. Again,
>> Arjan's proposal on CallerPrincipal and GroupPrincipal[5] sounds pretty
>> good.
>> - Improve TCK
>>
>> If JSR 375 could mandate servers to provide a JACC that implements some
>> methods even in a propietary way, I'd personally be happy with that as a
>> starting point. What do you think of that?
>>
>>
>> [1]
>> https://docs.jboss.org/author/display/WFLY10/Java+Authorization+Contract+for+Containers+%28JACC%29
>> [2]
>> https://github.com/ggam/Payara-Server-Documentation/blob/eec7c0582444acf5b52c30e18832d4e6213f1ba8/documentation/core-documentation/jacc.md
>> [3] https://java.net/jira/browse/SERVLET_SPEC-157
>> [4]
>> http://arjan-tijms.omnifaces.org/2015/03/java-ee-authorization-jacc-revisited.html
>> [5]
>> http://arjan-tijms.omnifaces.org/2014/02/jaas-in-java-ee-is-not-universal.html
>>
>> On Mon, Jul 11, 2016 at 9:09 PM, Ron Monzillo <ron.monzillo_at_oracle.com>
>> wrote:
>>
>>> Arjan and Guillermo,
>>>
>>> Thanks for the taxonomy of possible solutions. FWIW, the first three
>>> seem most compatible with the JACC SPI and policy enforcement model.
>>>
>>> Regarding the 1st, please note that I was not advocating that JACC make
>>> it mandatory for JACC providers
>>> to be loaded via the extension mechanism, but I would be interested in
>>> investigating whether
>>> it would be reasonable to recommend that the extension mechanism be used
>>> as a universally
>>> supported provder loading mechanism.
>>>
>>> As I understand the platform spec, all compatible containers are
>>> required to support the
>>> extension loading mechanism. If so, that existing requirement should be
>>> sufficient to bootstrap
>>> JACC in a common way on all application servers and then, within a
>>> specific JACC provider
>>> you could bootstrap the per application policy environment you are
>>> seeking (I presume as part of JSR 375).
>>>
>>> If the extension mechanism is not suitable for use by JACC, then I think
>>> we should consider requiring support
>>> (in JACC) for an approach like the other 2 of your first three.
>>>
>>> That said, if JSR 375 were to use JACC in this fashion, it would likely
>>> interfere
>>> with the existing use of JACC by the container...; which suggests that
>>> what you are looking for
>>> would require fundamental changes to JACC or its use model; as suggested
>>> by your reference to the
>>> JASPIC factory (as precedent for per application policy enforcement).
>>>
>>> The JACC model is basically a common policy enforcement engine applied
>>> to per application policy; in
>>> which any application context required to enforce application specific
>>> policy is made available to the
>>> policy enforcement engine via a combination of callbacks and
>>> interceptors.
>>>
>>> It looks like you are looking for per application policy engines/logic,
>>> and I guess I'd like to
>>> get a better handle on your use cases, before I am convinced that it
>>> would be useful to
>>> standardize per application Policy providers as part of JACC.
>>>
>>> It would also help if you can clarify what you are looking for from
>>> JACC.
>>> JACC will cause the container to convey the policy rules (obtained from
>>> DD's and annotations)
>>> to your provider via the policy configuration interface. JAcCC will also
>>> cause the container to invoke
>>> your provider to make pre-dispatch and programmatic access checks.
>>>
>>> Ron
>>>
>>>
>>> On 7/8/16 6:30 PM, arjan tijms wrote:
>>>
>>> Hi Ron,
>>>
>>> Great hearing from you!
>>>
>>> On Fri, Jul 8, 2016 at 5:01 PM, Ron Monzillo <ron.monzillo_at_oracle.com>
>>> wrote:
>>>
>>>> Note that does NOT rule out the possibility of replacing the JRE scoped
>>>> Policy provider, with a provider that loads and delegates to
>>>> application specific providers...
>>>>
>>>
>>> That would ultimately be what's needed. With that JSR 375 can install
>>> it's own provider for a single web app, just like it currently installs its
>>> own JASPIC SAM and then builds on top of that.
>>>
>>> JSR 375 could then provide its own API to provide access to the
>>> (in-memory) collection of permissions (like WebResourcePermission).
>>>
>>>
>>>
>>>> but I view the problem at hand,
>>>> as being where to put the replacement for the default java Policy
>>>> implementation class.
>>>>
>>>
>>> Indeed, that's problem number 1. As you may remember, I faced enormous
>>> difficulties installing this replacement on servers like Geronimo and
>>> JBoss.
>>>
>>> Closely related to that, it may be worth it to look into the possibility
>>> of defining a standard JACC factory anyway to install a global JACC
>>> provider from within a web app. After all, JASPIC also allows one to set a
>>> global SAM (by proving a null for the app context id).
>>>
>>>
>>>
>>>> It might also be feasible to change JACC
>>>> such that it uses an application scoped Policy object that is distinct
>>>> from that used by the rest of the JRE, but at least on the surface
>>>> that seems like a new version of JACC (or perhaps thats what JSR 375
>>>> is).
>>>>
>>>
>>> JSR 375 definitely does not try to be JACC (or JASPIC for that matter).
>>> At least, that's what I (and Alex back then) are trying hard to avoid. What
>>> JSR 375 does attempt is first and foremost providing a higher level, ease
>>> of use, abstraction/wrapper on top of JASPIC and hopefully JACC.
>>>
>>> But as it stands, JSR 375 has a hard time "connecting" to JACC. At most
>>> JSR 375 could provide a JACC provider that loads and delegates to
>>> application specific providers, and then mandates that IFF JSR 375 is used
>>> and IFF "some kind" of configuration is encountered in the application,
>>> then the application server vendor must make sure this JSR 375 provided
>>> JACC provider is installed.
>>>
>>> But I'm not sure if this is really allowed, and if it's allowed I think
>>> it puts a great burden on the application server vendor who somehow has to
>>> make sure it works.
>>>
>>> I'd much rather use a portable API/SPI instead of demanding something in
>>> the spec text and then hope it turns out well in practice.
>>>
>>>
>>>>
>>>> Also, since JACC requires compatibility with the JRE security Policy
>>>> replacement mechanism, so it may be feasible to adopt
>>>> a uniform replacement strategy that is based on loading the classes
>>>> from within the extension or lib area of the JRE. I am not sure
>>>> if that would be acceptable
>>>>
>>>
>>> JRE would be the absolute last resort. Java EE developers already
>>> dislike modifying the application server for a single application, but
>>> modifying the JRE is often a no go. The JRE on a developer's desktop often
>>> runs many different application servers and thus many different apps.
>>>
>>> Still, I tried putting the jar with the JACC provider there, and
>>> Geronimo and JBoss specifically still would not find it :(
>>>
>>>
>>>> and am interested in hearing of any other ideas you may have as to
>>>> defining where such (JRE-wide)
>>>> provider jars could be loaded from.
>>>>
>>>
>>> For Java EE this remains a difficult thing, as it typically tries to
>>> avoid going into product details. So stating that the server must provide a
>>> directory where it scans for the jar file is difficult I think, as is
>>> requiring that there's a product specific CLI or admin console function
>>> available that accepts a jar containing a JACC provider.
>>>
>>> That said any of the following would be an improvement:
>>>
>>> * Mandating JACC providers be loaded from the JRE's extension folder
>>> * Define a directory in the server, e.g. [glassfish home]/extensions
>>> * Define an extra system property that contains the path to jar. E.g.
>>> -Djavax.security.jacc.policy.provider.location=/opt/myprovider.jar
>>> * Define a new archive containing the JACC provider that can be deployed
>>> standalone or as part of an ear, just like .rar archives for JCA
>>> * Work with the EG for the new Java EE Management API to have them
>>> support the deployments of archives containing a JACC provider (but this EG
>>> is rather quiet at the moment)
>>> * Define a factory that applications can use to register the JACC
>>> provider, just like applications can do for a JASPIC SAM.
>>>
>>> I somewhat ordered the list where latter items would IMHO be more
>>> desirable solutions.
>>>
>>> Kind regards,
>>> Arjan Tijms
>>>
>>>
>>>
>>>
>>>
>>>>
>>>>
>>>> Ron
>>>>
>>>>
>>>> On 7/2/16 4:04 PM, arjan tijms wrote:
>>>>
>>>> Hi
>>>>
>>>> Thanks for starting this discussion. The current way to register a JACC
>>>> provider is indeed too difficult . This was discussed a while ago as well,
>>>> see
>>>> https://java.net/projects/jacc-spec/lists/users/archive/2015-03/message/0
>>>>
>>>> In the current climate, a MR is not the easiest thing, unfortunately.
>>>> Ron, what do you think?
>>>>
>>>> Alternatively, JSR 375 could provide a standard compliant JACC provider
>>>> and then *demand* Java EE implementations to have this install by default.
>>>> I don't know if this is feasible. Again a question to Ron; would you think
>>>> this is reasonable or even allowed for a JSR to do?
>>>>
>>>> Kind regards,
>>>> Arjan Tijms
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Sat, Jul 2, 2016 at 8:25 PM, Guillermo González de Agüero <
>>>> z06.guillermo_at_gmail.com> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> I need to register my own JACC provider to change the default security
>>>>> behaviour of my application. Problem there's no standard mecanism to
>>>>> register a custom provider, and moreover, vendor specific mechanisms are
>>>>> incredibly difficult to use[1].
>>>>>
>>>>> I would like to have an option to register a custom JACC provider from
>>>>> a web module, just like we can already register a SAM. This could be a
>>>>> workaround for [2] and would facilitate JSR375 Security Spec to provide a
>>>>> more integrated solution.
>>>>>
>>>>> This change should be done in a MR and included in Java EE 8.
>>>>>
>>>>>
>>>>> Regards,
>>>>>
>>>>> Guillermo González de Agüero.
>>>>>
>>>>> [1]
>>>>> http://arjan-tijms.omnifaces.org/2015/01/java-ee-authorization-jacc-revisited.html
>>>>> [2] https://java.net/jira/browse/SERVLET_SPEC-157
>>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
> Regards,

Guillermo González de Agüero


[1] https://java.net/jira/browse/SERVLET_SPEC-157