JSR 375 (JavaEE Security API)

JSR 375 (JavaEE Security API)

On February 2nd, 2017, we held our second NLJUG JCP meeting. This time, the subject of the event was the JSR 375 specification (“JavaEE Security API”), which is scheduled for Java EE 8 and 9.

The programme for this evening looked like this:

  • We started out with a nice dinner buffet, generously provided by our host of the evening, CGI Nederland.

  • Then an introduction into the specification was given by Rudy De Busscher, Expert Group member for JSR 375, with plenty of room for questions. Another EG member, Arjan Tijms, was also present and provided us with some very insightful answers.
    (see http://www.slideshare.net/rdebusscher/what-is-tackled-in-the-java-ee-security-api-java-ee-8 for the slides)

  • After a short coffee break, the participants got the chance to get some hands-on experience with the Security API using this workshop: https://github.com/EelcoMeuter/JSR-375-examples

  • We finished the evening with a few drinks, while informally discussing the Security API (and JavaEE in general).

 

During and after the meeting we tried to collect feedback. The amount of responses to this was limited, at best, and mostly on the organisation. So when the Early Draft Review of the specification was released (the review period runs from March 13th to April 12th), we asked the participants again for feedback. The following overview collects the remarks and, hopefully, the responses and actions the Expert Group provides.

Questions and remarks on the specification

Overall:

Q: There is no functionality present for managing identities in the IdentityStore, e.g. for allowing new users to sign up in an application and for having authorizations given or withdrawn from within an application. Is this foreseen for a future version, or will this be left to non-standard extensions?

A (from Arjan Tijms):

It has been discussed extensively and the initial proposal even had a rather large interface to encompass this.
However, in the majority of cases (that we found) the application knows what store is being used. I.e. the IdentityStore wraps a UserService, roughly as follows;
@ApplicationScoped
public class MyAppIdentityStore implements IdentityStore {
  @Inject
  private UserService userService;
  @Override
  public CredentialValidationResult validate(UsernamePasswordCredentialcredential) {
    return validate(() -> userService.getByEmailAndPassword(
      credential.getCaller(), credential.getPasswordAsString()));
  }
  // ...
}
So there the app already knows that users can be added via its own UserService, and the IdentityStore interface is, basically, a way to let the container interact with that.
Now the other way around, that the container configured an unknown identity store, and that the application wants to add users to this unknown store in a portable way, was not specified. The reason, as with quite a lot of things, is related to available resources.

Q: Chapter 3 mentions user groups, and chapter 4 mentions roles for users – however the relationship between these two concepts is not described anywhere. Should the mechanism by which this relation (i.e. users/groups mapping to roles/permissions) is configured be standardized too, or will this be left to non-standard extensions?

A (from Arjan Tijms):
This concerns the (in)famous group to role mapper.
See:
And for some more background:
We absolutely wanted to have this covered, but unfortunately have not done so till this far and now we’re running out of time pretty badly. I’d still like to have the most simple version of this covered though, which is standardising the default (1:1) mapping of groups to role.

Chapter 1 – Concepts:

Q: Why is the list, as proposed on the java.net project page, not used here as a starting point?

Q: Shouldn’t terms/abbreviations be added that are frequently used on the mailing list? E.g. SAM, HAM.
A (from Arjan Tijms):
Certainly good idea to add these ones.

Chapter 2 – Authentication Mechanism:

Q: Will the HttpAuthenticationMechanism (or a similar) interface become available for other inbound traffic handling container types? If not, why not?

A (from Arjan Tijms):
It’s indeed the idea that an interface like HttpAuthenticationMechanism could become available later for other types of security influx. Currently it’s only HttpAuthenticationMechanism since the web layer was prioritised, and for the Security API 1.0 we wanted to go for the lowest hanging fruit first.

Section 2.1 – Introduction:

Q: “… through the process of authentication”: isn’t this step actually called identification? (and, as stated correctly afterwards, authentication is the presenting of proof of identity)

A (from Arjan Tijms):
Note, will take a look at this 😉

Section 2.2 – Interface and Theory of Operation:

Q: The last method is called cleanSubject(), yet the term “subject” isn’t used anywhere else in the specification. Can another, already used term be applied here as well, or is it a significantly different entity?

A (from Arjan Tijms):

cleanSubject() is indeed a debatable term. Even to the point I already put it up for discussion a while ago, but few people on the list responded to this back then, so I left it as it was.
The term comes from the ServerAuthModule (the SAM), which is the lower level artefact the HttpAuthenticationModule indirectly builds on.
The cleanSubject() method responds to the HttpServletRequest#logout method call, so a more logical name could be logout as well.
Then again, “logout’ kinda assumes that there’s also a “login” method, yet there’s isn’t one. There’s HttpServletRequest#authenticate that causes validateRequest to be called. There *is* an HttpServletRequest#login, which quite unfortunately isn’t supported at the moment, but the idea would have been that it went straight to the IdentityStore (by-passing the authentication mechanism).

 Q: How do the calls to these methods fit in the lifecycle of a client session? Could this be illustrated in the specification?

A (from Arjan Tijms):
These calls and how they fit in both the request processing and the http session (which I assume is what is meant with “client session” here) are specified by the JASPIC specification, which is referenced by the Java EE Security specification. I think though we could make this a little bit more clear.

Section 2.3 – Installation and Configuration:

Q: Would it be clearer what is meant by “enabled bean” and “normal scoped” by referring to the defining sections in CDI specification?

A (from Arjan Tijms):
Good point, noted.

Q: Why is it not specified how the configuration over which mechanism is to be done?

A (from Arjan Tijms):

I think this means that it’s an application server specific override, which almost by definition can’t be specified as it’s done outside the application. If the management API for Java EE 8 (JSR 373) would have happened then we might have cooperated wit them to specify this.
As it stands, what Will means as I interpret it, is that the HttpAuthenticationMechanism that may be made available by the server happens to be set via e.g. the GlassFish, Payara, WildFly, etc admin consoles. If it does, then there should be some kind of configuration in that admin console to switch between the server defined one and the application defined one.
This configuration can’t be specified, since the entire concept of an admin console or cli etc is not within the Java EE spec domain.

Chapter 3 – Identity Store:

Q: The concept of multiple identity stores is introduced, but are there restrictions that should apply to each single store? Such as uniqueness of each identity entry within that store, or at least consistency of which entry is used for validation or returning groups for upon a given enquiry?

A (from Arjan Tijms):

There are no restrictions at this point in time enforced by the spec for uniqueness of entries. In general this may be impossible, as a store could potentially back an external provider that has no option to list the identities it contains.
There are facilities for marking some stores to be used for validation, and other stores to be used for returning groups.
Also, the spec anticipates that the default algorithm may not be sufficient for all use cases, and allows this to be replaced fully by means of providing a (CDI) alternative for the IdentityHandler.

Section 3.2.1 – Validating Credentials:

Q: Wouldn’t it be better to indicate the validate() method as MANDATORY for IdentityStores that declare themselves to have AUTHENTICATION or BOTH capability (instead of OPTIONAL)?

A (from Arjan Tijms):

These concepts are somewhat orthogonal. The default algorithm is to consult all stores that have been set to AUTHENTICATE or BOTH until one succeeds. This roughly corresponds to JAAS/PAM’s OPTIONAL, but is not fully equivalent.
Consult all until one succeeds is what’s done by some other popular security frameworks as well, e.g. Spring Security.
Using a custom IdentityHandler and keeping the metadata for which store is MANDATORY or OPTIONAL, etc “somewhere” third party code can basically emulate JAAS/PAM if it wants.

Q: Instead of providing a status value (or called “error code” in the review section), shouldn’t the signature of the method indicate that specific exceptions can be thrown in exceptional cases (such as the failure causes mentioned in the review section)?

A (from Arjan Tijms):

The question is whether failure in authentication is really an exceptional case and thus warrants an exception instead of a code. I’m not sure about the term “error code”. In JASPIC it’s called an AuthStatus, hence the original wording used “status”.
So if the questions is; should the FAILURE status code be an exception? Then the answer is likely “no, I personally don’t think so”.
However, if the question is more about “Should the method list the runtime exceptions it can throw”, then the answer is that it probably should.

Section 3.2.2 – Retrieving Caller Information:

Q: Wouldn’t it be better to indicate the getGroupsByCallerPrincipal() method as MANDATORY for IdentityStores that declare themselves to have AUTHORIZATION or BOTH capability (instead of OPTIONAL)?

A (from Arjan Tijms):

This is a very subtle one.
Initially it’s “no”, since having groups is and always has been optionally in Java EE. A caller can be authenticated, yet not be in any group.
So it’s perfectly fine for identity stores to return no groups for a given caller principal.
But… the subtlety here is that we may wish to distinguish between the store not knowing about the caller, and therefor not returning anything, and the store knowing the caller and having determined as a fact it has no groups.

Section 3.2.4 – Handling Multiple Identity Stores:

Q: How are different Credentials, spread over multiple identity stores, for the same user correlated with a single CallerPrincipal (which currently only contains a ‘name’ field)? How can it be prevented that Credentials for different users are correlated to the same CallerPrincipal? How can such consistency be enforced (or even be maintained)?

A (from Arjan Tijms):

The spec does not enforce this. It’s, at least for now, an application responsibility to ensure that if it wishes to use multiple identity store that they are compatible with each other.
Look at if from a different perspective; if the application (or its ops team) configures a single identity store, it’s their responsibility to ensure that store matches the application. I.e. one would not likely configure an identity store with public users in it for a company’s external web app, to an internal office application.
This is not unheard of, e.g. if I’m not mistaken then in JBoss/WildFly one can configure multiple stores for the certificate authentication mechanism. One can only validate the certificate, where the other can only provide the groups. There are, as far as I know, no specific framework facilities to make sure these two match.
If an application so wishes the single name field can always encode additional information. It’s an opaque string that each store and if needed the encompassing handler can interpret it in any way it likes.

Q: Shouldn’t the remark made in section 3.3, that equal priorities lead to an undefined calling order, be moved to this section? It seems more appropriate here.

A (from Arjan Tijms):

Good point 😉

Q: The reasoning behind why the identity stores are filtered for the two steps is missing (or implicit) from the process description. What is it, and should it be added to the section for clarification?

A (from Arjan Tijms):

The filtering is so that step 1 can easily consult all the stores that do AUTHENTICATE and step 2 the AUTHORISE ones. But an (independent) implementation does not necessarily have to do it this way.

Q: Shouldn’t the case where no VALID response was received, but errors did occur (as described in the third bullet of the review section), result in an exception being thrown?

A (from Arjan Tijms):

I’ve to take a better look at this tbh, but in general if with “error” an exception is meant then it would abort the entire algorithm right away. A failure status code would mean the credential did not validate and is not considered an exception, and would result in an overal failure return.

Section 3.3 – Installation and Configuration:

Q: Ad review section: Isn’t it confusing or possibly even just wrong to accept group data from an authentication-only identity store? Isn’t it so that the validation type is under the control of the application, while the process/implementation through which the group data is returned from such a store may not be?

A (from Arjan Tijms):

Yes & yes 😉 Accepting group data from an authentication-only store is wrong and will be rectified.
And indeed, the validation type is under the control of the application, but the internals of the store may not be, or even if it’s application controlled it may be that the same store is used for 2 different situations.
Btw, a few cosmetic changes will be made to the authentication type, basically it will become a return type of Set, and AUTHENTICATE and AUTHORISE will be called VALIDATE and GROUPS respectively.

Section 3.4 – Annotations and Built-in IdentityStore Beans:

Q: What is the reasoning behind the various default values for priority() as used in the annotations? Why is the order defined like this?

A (from Arjan Tijms):

I’m not sure, but great catch! I guess it may be a leftover from a quick initial test and was not adjusted afterwards.

Section 4.4 – Relationship to Other Specifications:

Q: Would it be a goal to have the existing ‘alternatives’ in the other specifications be deprecated for Java EE 9?

A (from Arjan Tijms):
The isCallerInRole etc methods from the securityContext could indeed be deprecated, but there’s always the delicate issue of specs wanting to be both totally independent from Java EE and part of Java EE.
In JSF for instance I have deprecated the native bean facility (in favour of the CDI one), but if Servlet would want to deprecate let alone remove HttpServletRequest#isUserInRole is questionable.

 

Typos

Section 2.1 – Introduction

In the third paragraph, first line: “… the iteraction…” should be “… the interaction…”

Third paragraph, third line: “… the construction an…” should be “… the construction of an…”

Section 2.2 – Interface and Theory of Operation Page 5, summary of cleanSubject(): “… the logout method…” should be “… the logout() method…”
Page 5, paragraph directly after the summary: redundant use of “for example” (twice), where “etc.” of “such as…” is used

Section 2.4 – Relationship to other specifications

Second paragraph, third line: “… method of servlet filter…” should be “… method of a servlet filter…”

Second paragraph, fifth line: “… validateRequest…” should be “… validateRequest()…”
Third paragraph, first line: “… build-in…” should be “… built-in…”
Section 3.1 – Introduction Third paragraph: “A primary advantage…” should be “The primary advantage…”(?)
Fourth paragraph, second line: “… passed in to it…” should be “… passed into it…”
Section 3.2.1 – Validating Credentials Page 9, section under review section: missing _ before “validate(Credential)_” to make it italic
Section 3.2.4 – Handling Multiple Identity Stores Second paragraph, fourth line: “… qualier…” should be “… qualifier…”
Page 12, one-but-last line: “… passed in to this method…” should be “… passed into this method…”
Section 3.4 – Annotations and Built-in IdentityStore Beans Page 15, mid-way: “All of all these beans…” should be “All of these beans…”
Chapter 4 – Security Context Various instances on pages 17 and 18: “SecurityContect” should be “SecurityContext”
Section 4.2 – Testing for Caller Data Last paragraph, second line: “… role determinatino…” should be “… role determination…”

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