Through the HICLASS UK research group, AdaCore has been developing security-focused software development tools that are aligned with the objectives stated within the avionics security standards. In addition, they have been developing further guidelines that describe how vulnerability identification and security assurance activities can be described within a Plan for Security Aspects of Certification.
A few days ago, someone asked on the Ada Drivers Library repository how to add support for the SAMD21 micro-controller. Nowadays, I would rather recommend people to contribute this kind of micro-controller support project to the Alire ecosystem. I started to write a few instructions on how to get started, but it quickly became a blog-worthy piece of text.
The developers of CycloneTCP library at Oryx Embedded partnered with AdaCore to replace the TCP part of the C codebase by SPARK code, and used the SPARK tools to prove both that the code is not vulnerable to the usual runtime errors (like buffer overflow) and that it correctly implements the TCP automaton specified in RFC 793. As part of this work, we found two subtle bugs related to memory management and concurrency. This work has been accepted for publication at the upcoming IEEE SecDev 2021 conference.
This blog entry shows how to define an abstract data type that allows tasks to block on objects of the type, waiting for resumption signals from other components, for at most a specified amount of time per object. This "timeout" capability has been available in Ada from the beginning, via select statements containing timed entry calls. But what about developers working within the Ravenscar and Jorvik tasking subsets? Select statements and timed calls are not included within either profile. This new abstraction will provide some of the functionality of timed entry calls, with an implementation consistent with the Ravenscar and Jorvik subsets.
NVIDIA has been using SPARK for some time now to develop safety- and security-critical firmware applications. At the recent DEF CON 29, hackers Zabrocki and Matrosov presented how they went about attacking NVIDIA firmware written in SPARK but ended up attacking the RISC-V ISA instead!Zabrocki starts by explaining the context for their red teaming exercise at NVIDIA, followed by a description of SPARK and their evaluation of the language from a security attack perspective. He shows how they used an extension of Ghidra to decompile the binary code generated by GNAT and describes the vulnerability they identified in the RISC-V ISA thanks to that decompilation. Matrosov goes on to explain how they glitched the NVIDIA chip to exploit this vulnerability. Finally, Zabrocki talks about projects used to harden RISC-V platforms.
Part of AdaCore's ongoing efforts under the HICLASS project is to demonstrate how the SPARK technology can play an integral part in the security-hardening of existing software libraries written in other non-security-oriented programming languages such as C. This blog post presents the first white paper under this work-stream, “Security-Hardening Software Libraries with Ada and SPARK”.
This post continues our adventures with SPARKNaCl - our verified SPARK version of the TweetNaCl cryptographic library. This time, we'll be looking at yet more performance improvement via proof-driven "operator narrowing", porting the library to GNAT Community 2021, and the effect that has on proof and performance of the code.
As we've seen previously in Ada 2022 support in GNAT, the support for Ada 2022 is now mostly there for everyone to take advantage of. We're now crossing fingers for this new revision to be officially stamped by ISO in 2022.
We are happy to announce that the GNAT Community 2021 release is now available via https://www.adacore.com/download. Here are some release highlights:
The Ada 2022 draft defines a new tasking profile named Jorvik (pronounced “Yourvick”), based directly on the standard Ravenscar profile. Jorvik relaxes certain restrictions in order to increase expressive power for real-time/embedded Ada and SPARK applications. We will explore the details in this blog entry.
I am following the evolution of the embedded Rust community and in particular the work of James Munns from Ferrous-Systems. One of the projects that caught my attention is bbqueue, a single producer, single consumer, lockless, thread safe queue, based on BipBuffers.
Ada has a concurrency construct known as “entry families” that, in some cases, is just what we need to express a concise, clear solution.
In the integrated development environment, GNAT Studio, there is now a plugin that inserts the generated Global contracts inline with the code.
Following my last blog entry, further experiments show how the performance of SPARKNaCl can be doubled (again), plus analysis of worst-case stack usage and code size at all optimization levels.
This blog goes into the details of both measuring and improving the runtime performance of SPARKNaCl on a real "bare metal" embedded target, and comparing results with those for the original "TweetNaCl" C implementation.
Beyond the great look, the Mini SAM M4 provide a powerful 120 Mhz Microchip SAMD51 Cortex-M microcontroller, a couple of LEDs and a user button. Let's program it with Ada.
Using GNAT Pro with containerization technologies, such as Docker, is so easy, a whale could do it!
In this blog post I want to present a new tool that allows one to very quickly and easily start Ada programming on any ARM Cortex-M or RISC-V microcontroller.
Some of you may recall an AdaCore blog post written in 2017 by Thales engineer Lionel Matias titled "Leveraging Ada Run-Time Checks with Fuzz Testing in AFL". This insightful post took us on a journey of discovery as Lionel demonstrated how Ada programs, compiled using GNAT Pro and an adapted assembler pass can be subjected to advanced fuzz testing. In order to achieve this Lionel demonstrated how instrumentation of the generated assembly code around jump and label instructions, could be subjected to grey-box (path aware) fuzz testing (using the original AFL v2.52b as the fuzz engine). Lionel explained how applying the comprehensive spectrum of Ada runtime checks, in conjunction with Ada's strong typing and contract based programming, enhanced the capabilities of fuzz testing beyond the abilities of other languages. Ada's advanced runtime checking, for exceptions like overflows, and the scrutiny of Ada's design by contract assertions allow corner case bugs to be found whilst also utilising fuzz testing to verify functional correctness.
Charles Villard, Cyril Etourneau, Thomas Delecroix, Louise Flick worked together in the ADArrose project. It won the student prize in the Make with Ada 2019/20 competition. This project was originally posted on Hackster.io here. For those interested in participating in the 2020/21 competition, registration is now open and project submissions will be accepted until Jan 31st 2021, register here.