We explore multi-stage programming to detect side-channel vulnerabilities in hardware-software systems via the technique of Collapsing Towers of Interpreters. The idea is to specialize an assembly program wrt a hardware processor written as a staged interpreter (including micro-architectural details like speculation and data caching) and produce a residue C program semantically equivalent to the original assembly program but with explicit micro-architectural details, including the side-channel information reified into first-order variables. An off-the-shelf analyzer (like CBMC) can then analyze the residue C file to check whether the first-order timing and secret inputs are noninterfering.
This work is an adaptation of the work described in PEPM '25 to Scala 3 and ELMS.
The source code corresponding to that paper can be found in src/test/scala/elms.
This generator project requires sbt and Java version >21. We depend on ELMS (vendored).
Running sbt test from the root will run all the tests,
generating .actual files and checking them against the .check files in src/out.
Failing tests will leave the generated .actual files for inspection.
Snapshot files mostly follow the naming convention of [testfile]/[suffix].check.c.
The examples are verified using CBMC as follows:
cbmc -DCBMC --verbosity 4 --slice-formula --unwind 1000 --refine --compact-trace <file.c>
For convenience, we also provide verify, invoked as
./verify <file1.c> <file2.c> ...
Note that not all .check.c files are expected to pass verification -- most
are intended to demonstrate that CBMC can detect a vulnerability. We are working
on making a comprehensive list of which files are expected to pass and which do
not.
We use the C Bounded Model Checker (CBMC) as an off-the-shelf analyzer since our residue C programs are ordinary programs where timing is an ordinary first-order variable. Some pointers: