Proposal: mandatory versioning metadata for modules

[Pascal Rapicault]

Like you I'm a bit surprised by the optional nature of the version number.
However even if the version was made mandatory I don't think this would
suffice to identify jars (btw, another case of jar modification is shading
(the jar is copied into another one, and sometimes the package renamed)).
For example people could forget to update the jar version or do it
deliberately (because they don't want to update dependent libs), or simply
strip it when aggregating jars.

There is a lot of research papers talking about finding similarities in
jars, but the one that I found to be the most robust to do this kind of
work is http://dl.acm.org/citation.cfm?doid=1985441.1985468

HTH

Pascal


On Thu, October 25, 2012 01:03, David Jorm wrote:
> Hi All
>
> I am currently working on a system for tracking JAR files that expose
> known security flaws, identifying them by checksums or metadata. In short,
> both of these mechanisms have shortcomings. Checksums of JAR files provide
> zero false positives, but have huge scope for false negatives. Whenever a
> JAR is re-compiled, bits in the JAR change and the checksum changes.
> Metadata is unreliable, as META-INF/MANIFEST.MF does not require the
> inclusion of title and version elements. A more detailed overview is
> available here [0]. To give an example of the problem I'm attempting to
> solve, Spring 2.5.6 exposes a remote code execution flaw. It is fixed in
> Spring 2.5.6.SEC01. I want to be able to distinguish between 2.5.6 and
> 2.5.6.SEC01 to identify whether a system is deploying the vulnerable JAR.
> I can't
> just use a checksum of the file, because if anyone recompiles it, bits
> change. I also can't rely on the MANIFEST.MF, because it may or may not
> include any version data; it may not even identify the title of the
> component as "Spring".
>
> The Jigsaw project offers a great opportunity to solve this problem.
> However, I note in the documentation [1]:
>
> "A /module/ is a collection of Java types (/i.e./, classes and interfaces)
> with a name, an optional version number, and a formal description of its
> relationships to other modules."
>
> The problem here is "optional" version number. What I'm trying to achieve
> is mandatory minimal version metadata. What do people think about making
> version number a requirement for Jigsaw modules? Would that be feasible
> and if so would it be desirable?
>
> Thanks
> --
> David Jorm / Red Hat Security Response Team
>
> [0] http://www.slideshare.net/davidjorm/tracking-vulnerable-jars
> [1] http://cr.openjdk.java.net/~mr/jigsaw/notes/jigsaw-big-picture-01
>