Surviving JEP411 deprecation [WAS]: Implementing an Authorization framework on Java.

Peter Firmstone peter.firmstone at zeus.net.au
Thu Feb 9 23:21:02 UTC 2023


Please undeprecate DomainController interface, AccessController, 
AccessControlContext and Subject methods, while removing the remaining 
methods in JEP411.

Just document that these methods don't do anything by default, and use 
the null object pattern where appropriate.

Deprecation is causing developers to remove code that we need, this is 
undoing years of hard work, I'm appealing to you to minimise harm where 
possible.

eg: https://github.com/apache/lucene/issues/11801

-- 
Regards,
  
Peter

On 10/02/2023 9:03 am, Peter Firmstone wrote:
>
> Maybe I had the wrong Subject?
>
> I'm still trying to figure out how to migrate before removal of 
> deprecated API's.
>
>  1. Our software architecture is designed and currently relies on
>     classes in JEP411 for authorisation decisions.
>  2. It's not possible for our software to have security bolted on as
>     an afterthought, following removal of authorization.
>  3. Without authorization, we cannot allow the JVM to have access to
>     sensitive information.
>  4. We could place the JVM inside an isolated VM as suggested by
>     JEP411 proponents, but we can no longer allow the JVM to have
>     access to sensitive information.   It is technically possible to
>     do this, provided we accept we could no longer use encryption or
>     authentication, as we cannot introduce sensitive information into
>     the JVM, then we could use observability tools as a watchdog, to
>     shutdown and restart the VM if it becomes compromised.   However,
>     that leaves us with very limited functionality.
>
> I realise that OpenJDK likely thinks this is BS, we can just safely 
> remove SM, it's obsolete now right?
>
> The problem is, we don't fit the standard category of server 
> programming, eg: once the JVM's warmed up, it no longer dynamically 
> loads classes, hotspot has compiled them to native binary code; a 
> server that fits the publish subscribe model, where it only need parse 
> and validate incoming data from clients, and publish responses.  
> Server programming is OpenJDK's target market, we get that.   Anything 
> in the client space is frowned upon, we get that too, but we're not in 
> the client space.   Our clients are also servers.
>
> Our distributed service architecture provides dynamic discovery of 
> services (globally over IPv6).   We rely on Authentication, Encryption 
> (Privacy) and Authorization.   Clients of services are often required 
> to download code dynamically, clients and services first discover and 
> authenticate available service registrar's using an X500 IPv6 
> multicast discovery process, with checksums to validate details 
> required to establish a unicast connection.   Unicast IPv6 TCP with 
> Encryption is used to ensure that communications are private between 
> authenticated connections while establishing connections to service 
> registrar's.
>
> Nodes in the distributed network, aren't distinguished as servers and 
> clients, a node that acts as a client will also provide services, even 
> if it's just listening to an event service.   All threads are run with 
> authenticated client endpoint Subject's, and service responses with 
> server Subject's, to allow the use of authenticated TLS connections.
>
> After nodes have discovered each other, the connection is established 
> like so:
>
>  1. Authentication & Establish an Encrypted connection.
>  2. The service provides the client with;  code signer certificates,
>     if the service requires codebase download, or it may provide a
>     security hash, used to validate files, it will also communicate a
>     string that represents URL's from which code can be downloaded. 
>     It will also communicate any permissions it requires.   The client
>     Subject is allowed to grant a restricted set of permissions.   The
>     client may elect to grant the requested permissions, if it has the
>     privileges to do so.
>  3. The client provisions a ClassLoader, that's a child of the
>     ClassLoader that contains the Service's public API, the identity
>     of this ClassLoader is determined by the CodeSource URI's as well
>     as the Authenticated identity of the Service. The ClassLoader of
>     the service proxy represents it's identity in authorization
>     decisions at the client.   Other service proxy's may use the same
>     codebase URL's, but unless they have identical identity, cannot
>     load their classes into another service proxy's ClassLoader.
>  4. At this point, the client unmarshal's the service proxy's Object
>     state into the ClassLoader, it doesn't use Java de-serialization
>     to do this, just in case anyone is curious.
>  5. Only ClassLoaders are responsible for Class resolution, codebase
>     annotations are not used, neither is RMIClassLoader used to
>     resolve classes.
>  6. Now the client (and server) applies constraints to their service
>     endpoints, placing restrictions on the level of encryption the
>     service can use for network communications, or the Principal's the
>     Subject that invokes the service must have.
>  7. The client can now use the service, by passing parameters to the
>     proxy's methods and accepting returns.   The service proxy may
>     accept or return other services, these services will have the same
>     constraints applied, unless clients or services, apply new
>     constraints.
>  8. A JVM node may have any number of services proxy's while also
>     providing services to other nodes, of many different identities,
>     numerous services may participate in transactions, each one with
>     it's own identity.
>
> During this process permissions are granted as they are required, once 
> a service is no longer used, its ClassLoader becomes unreachable, 
> permissions granted dynamically are removed.   The client environment 
> is otherwise locked down with least privilege policy files, that were 
> generated and audited during deployment.
>
> We would like to continue to invest in the development of this 
> software, it's performant, it scales, encryption is very fast, thanks 
> to recent developments in Java session tickets.  We've eliminated 
> unnecessary DNS calls (the JVM makes many of these, eg URL, 
> SecureClassLoader, CodeSource), and cleared out synchronized and 
> blocking code, replaced it with concurrent non blocking code where 
> possible.   It's well tested, much time has been invested into static 
> analysis and cleaning up and modernizing code.   All our hotspots are 
> native JVM methods.   I suspect this is why we are finding bugs in 
> your TLS code, it isn't thread safe ;)
>
> Hopefully there is a future for this software, however it will depend 
> our ability to migrate to new versions of Java as they're released.
>
> At least allow us just these few classes to remain (un-deprecated 
> please, so developers aren't motivated to remove their privileged 
> calls), even if they contain no implementation, so that we may 
> instrument them, as we attempt to stay current with OpenJDK.
>
> We are not asking OpenJDK to maintain OpenJDK security using an 
> authorization framework, we are just asking you to make it possible 
> for us to maintain our software's security ourselves while running on 
> your platform.  It's not really possible for us to run on anything else.
>
> -- 
> Regards,
>   
> Peter.
> On 9/02/2023 10:20 am, Peter Firmstone wrote:
>>
>> I don't think I'm really asking for much here.   JEP411's plan will 
>> destroy our ability to manage user and service authorization in our 
>> existing software, at least cut us a little slack.  I wish we built 
>> our software on some other authorization API, unfortunately we didn't.
>>
>> We're just trying to migrate as best we can to future versions of Java.
>>
>> -- 
>> Regards,
>>   
>> Peter Firmstone
>> On 7/02/2023 12:53 pm, Peter Firmstone wrote:
>>>
>>> Hello OpenJDK folk,
>>>
>>> SecurityManager, AccessController and AccessControlContext will be 
>>> removed in a future version of Java.
>>>
>>> Just briefly: Our software is heavily dependant on Java's 
>>> Authorization framework, we use ProtectionDomain's to represent 
>>> remote services for authorization decisions.  We are working out how 
>>> to implement a new authorization framework after SecurityManager's 
>>> removal.
>>>
>>> Many libraries call AccessController#doPrivileged methods, when 
>>> these methods are removed, we're going to have a big problem with 
>>> viral permissions.   Restricted authorization will become 
>>> meaningless if it has to be granted to all domains on a call stack.
>>>
>>> https://github.com/opensearch-project/OpenSearch/issues/1687
>>>
>>> Retaining methods in the platform that developers can instrument 
>>> will provide a common frame of reference for authorization 
>>> decisions, that's runtime backward non-breaking, without burdening 
>>> OpenJDK with maintenance.
>>>
>>> I'm requesting retaining the DomainController interface, 
>>> AccessController, AccessControlContext and Subject methods as 
>>> no-op's for instrumentation?    Please leave them deprecated as 
>>> no-op's, but not "deprecated for removal".
>>>
>>> https://github.com/pfirmstone/HighPerformanceSecurity
>>>
>>> Some thoughts:
>>>
>>>  1. Ability to disable finalizers in Java 18 onwards is important to
>>>     prevent finalizer attacks when instrumenting constructors to
>>>     throw a RuntimeException.
>>>  2. Guard#check methods can be no-op's for instrumentation.   If I
>>>     can replace all instances of SecurityManager#checkPermission in
>>>     OpenJDK with Guard#check, I can contribute the patches, this
>>>     will assist greatly in the transition process of retaining
>>>     existing hooks, while developing replacements.
>>>  3. Reduce the size of the Java Platform's trusted computing base by
>>>     giving all system ProtectionDomain's a CodeSource with a
>>>     non-null meaningful URL.   Unfortunately Java Serialization is
>>>     in the base module, so we cannot authorize it's use with a
>>>     permission check, as the base module needs AllPermission, it has
>>>     to be managed with serial filters
>>>     (https://dzone.com/articles/a-first-look-into-javas-new-serialization-filterin
>>>     - perhaps someone will write a serialfilter generation tool that
>>>     works similarly to our POLP policy generation tool?). 
>>>     Privileges cannot be elevated by an authenticated Subject, when
>>>     all domains on the call stack are already privileged.  If
>>>     Serialization was in a different ProtectionDomain, then we could
>>>     prevent de-serialization for unauthenticated Subject's.  
>>>     Perhaps OpenJDK might consider moving Serialization into a
>>>     different module in future before it's eventual removal?
>>>  4. Instrument all data parsing methods with guard checks, eg XML.  
>>>     This allows authorization decisions to parse remote data based
>>>     on the Principal's of the remotely authenticated Subject, to
>>>     prevent injection attacks.
>>>  5. We already have principle of least privilege policy generation
>>>     tools and efficient policy checking tools for authorization in
>>>     place.   These allow for simple policy file generation,
>>>     auditing, editing and deployment.
>>>
>>> -- 
>>> Regards,
>>>   
>>> Peter Firmstone
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