At Galois, we develop formal verification tools that rely on a variety of automated solvers for answering mathematical queries. The main solvers we use are called Satisfiability Modulo Theories (SMT) solvers.  These solvers offer the ability to answer questions such as “find me inputs for which a mathematical property holds.”  We have found these tools […]

Check out these ICFP presentations by Galois team members: Efficient Lookup-Table Protocol in Secure Multiparty Computation Video Presentation John Launchbury: watch video – http://www.youtube.com/watch?v=I79PwWpUx9c Paper John Launchbury, Iavor S. Diatchki, Thomas DuBuisson, and Andy Adams-Moran. 2012. Efficient lookup-table protocol in secure multiparty computation. In “Proceedings of the 17th ACM SIGPLAN International Conference on Functional Programming” […]

Galois is pleased to host the following tech talk. These talks are open to the interested public. Please join us! title:Combining Denotational and Operational Semantics for Scalable Proof Development speakers:Adam Foltzer time:Tuesday, 19 July 2011, 10:30am location: Galois Inc. 421 SW 6th Ave. Suite 300, Portland, OR, USA (3rd floor of the Commonwealth building) abstract:Interpreters […]

Galois is in the business of building trustworthy software. Such software will have well-defined behavior, and that behavior is assured in some way, whether via model checking, testing, or formal verification. SMT solvers — extensions to SAT solvers with support for variables of non-boolean type — offer powerful automation for solving a variety of assurance […]

Performing consistent builds is critical in software development, but the current system in GHC/Haskell of per-user and per-system GHC package databases interferes with this need for consistency. It is difficult to precisely identify the dependencies of a given project, and changes necessary to enable one project to build may render another project inoperable. If each […]

Copilot is an embedded domain-specific language designed by Galois, that allows you to generate assured, embedded C code from programs written essentially as Haskell lists (using Atom as a backend for the C code generation).  Lee Pike has written a tutorial on how to use Copilot to program an Arduino controller to play “Jingle Bells”. Read the full tutorial on […]

During BelHac, the Ghent Haskell Hackathon in November, we took an afternoon session for a “Functional Programming in Industry” impromptu workshop. The following are slides I presented on Galois’ experience building a business using our functional programming expertise, in particular, Haskell. The talk describes three case studies where “functional thinking” helped shape the solution to […]

Galois is offering a four‐day Cryptol course for those interested in exploring the capabilities of the Cryptol workbench.The course is highly participatory: we will work on a series of exercises for each new topic, using the Cryptol toolset interactively. Prospective participants should have experience writing programs and some knowledge of cryptography. Those who complete the course will have the skills necessary to develop high‐assurance, high‐performance cryptographic algorithms in Cryptol. A tentative outline and further information can be found in the course flyer. Interested parties should contact Dr. Sally Browning via e-mail at sally@galois.com, or call her at (503) 808 7151.

John Launchbury presented the Orc language for concurrent scripting at the Haskell Workshop, 2010 in Baltimore.

Concurrent Orchestration in Haskell

John Launchbury

Trevor Elliott

The talk slides are available in PDF or online.

We present a concurrent scripting language embedded in Haskell, emulating the functionality of the Orc orchestration language by providing many-valued (real) non-determinism in the context of concurrent effects. We provide many examples of its use, as well as a brief description of how we use the embedded Orc DSL in practice. We describe the abstraction layers of the implementation, and use the fact that we have a layered approach to establish and demonstrate algebraic properties satisfied by the combinators.

When writing software that uses open source libraries, the license of a dependency is a real concern. It becomes necessary to watch for license compatibility, as well as ensure that the terms of the license are satisfied when doing a source distribution.As a first attempt at license compatibility checking, we have added some extra checks in the configure step for Cabal, so that warnings will be generated if any direct dependencies have licenses that conflict with that of the configured package [1]. However, there are some limitations to this approach. First, this doesn’t rule out the possibility that a dependency of a package that is deemed compatible will conflict with the license of your executable. Second, it doesn’t allow for a BSD3 library to depend on a GPL library, where the conflict is only produced when an executable is produced from the combination.Some licenses place requirements on how a source or binary distribution can happen. For example, the BSD3 license requires you to include its copyright notice in any distribution you make.In order to speed up this process, we decided to try to extract this information from the GHC package database. According to the GHC manual, the license file should be tracked by the package database, though upon closer inspection, that field doesn’t seem to be tracked. In order to address this shortcoming, we developed a small patch to add this functionality in GHC and Cabal [2]. Using this patched version of GHC and Cabal, we’ve developed a small tool to walk the dependencies of a cabal package, and collect the license files that they have registered in the package database.Both of these patches are available for you to try out, attached to the tickets below, though they have been accepted and are expected to make it into the next release of Cabal.[1] http://hackage.haskell.org/trac/hackage/ticket/481[2] http://hackage.haskell.org/trac/hackage/ticket/710