AdaCore Blog

An Insight Into the AdaCore Ecosystem

by Fabien Chouteau

NVIDIA Security Team: “What if we just stopped using C?”

Today I want to share a great story about why many NVIDIA products are now running formally verified SPARK code. This blog post is in part a teaser for the case study that NVIDIA and AdaCore published today. Our journey begins with the NVIDIA Security Team. Like many other security oriented teams in our industry today, they were looking for a measurable answer to the increasingly hostile cybersecurity environment and started questioning their software development and verification strategies.

by Johannes Kliemann

Adding Ada to Rust

While implementing application logic in Ada or SPARK is an improvement over a pure C project, its weakest link is still the C code in the SDK. On the other hand, there are many libraries, board support packages, and SDKs written in Rust, easily usable with Cargo. So instead of building the Ada application on top of a C base, one could use a Rust base instead to combine the large catalog of ready-to-use software with Rust's safety features, providing a much more solid base for an Ada project.

by Yannick Moy

When Formal Verification with SPARK is the Strongest Link

Security is only as strong as its strongest link. That's important to keep in mind for software security, with its long chain of links, from design to development to deployment. Last year, members of NVIDIA's Offensive Security Research team (aka "red team") presented at DEF CON 29 their results on the evaluation of the security of a firmware written in SPARK and running on RISC-V. The ended up not finding vulnerabilities in the code, but in the RISC-V ISA instead. This year, the same team presented at DEF CON 30 a retrospective on the security evaluation of 17 high-impact projects since 2020. TL;DR: using SPARK makes a big difference for security, compared to using C/C++.

#Security    #SPARK    #Formal Verification   

by Fabien Chouteau

Embedded Ada/SPARK, There's a Shortcut

For years in this blog my colleagues and I have published examples, demos, and how-to’s on Ada/SPARK embedded (as in bare-metal) development. Most of the time, if not always, we focused on one way of doing things: to start from scratch and write everything in Ada/SPARK, from the low level drivers to the application. While this way of doing Ada/SPARK embedded will yield the best results in terms of software quality, it might not be the most efficient in all cases. In this blog post I want to present an alternative method to introduce Ada/SPARK into your embedded development projects.


by Paul Butcher

Join us at the High Integrity Software (HIS) Conference 2022!

After two years of virtual events, we are very happy to report that the High Integrity Software Conference (HIS) will be making a physical comeback on Tuesday 11th October 2022 at the Bristol Marriott Hotel City Centre, Bristol, UK. Since 2014, AdaCore has been co-organising the event with Capgemini Engineering (previously known as Altran Technologies, SA). The success and growth of the conference have ensured it remains a regular fixture for returning delegates, and the exciting lineup for this year's event will ensure HIS 2022 is no exception!

by Claire Dross

Handling Aliasing through Pointers in SPARK

As I explained in a blog post a couple of years ago, pointers are subjected to a strict ownership policy in SPARK. It prevents aliasing and allows for an efficient formal verification model. Of course, it comes at the cost of restrictions which might not be applicable to all usage. In particular, while ownership makes it possible to represent certain recursive data-structures, those involving cycles or sharing are de-facto forbidden. This is a choice, and not every proof tool did the same. For example, the WP plug-in of Frama-C supports pointers with arbitrary aliasing. If some information about the separation of memory cells is necessary to verify a program, then the user shall give the annotation explicitly. I have investigated modeling pointers with aliasing in SPARK as indices in a big memory array. I will present the results of my experiments in this blog post. We will see that, while such a representation is indeed possible modulo some hiding in SPARK, it can quickly become rather heavy in practice.

#SPARK    #Data Structures    #Formal Verification   

by Yannick Moy , Claire Dross

Proving the Correctness of GNAT Light Runtime Library

The GNAT light runtime library is a version of the runtime library targeted at embedded platforms and certification, which has been certified for use at the highest levels of criticality in several industrial domains. It contains around 180 units focused mostly on I/O, numerics, text manipulation, memory operations. We have used SPARK to prove the correctness of 40 of them: that the code is free of runtime errors, and that it satisfies its functional specifications.

#SPARK    #Runtime    #Proof   

by Quentin Ochem , Florian Gilcher

AdaCore and Ferrous Systems Joining Forces to Support Rust

For over 25 years, AdaCore has been committed to supporting the needs of safety- and mission-critical industries. This started with an emphasis on the Ada programming language and its toolchain, and over the years has been extended to many other technologies. AdaCore’s product offerings today include support for the Ada language and its formally verifiable SPARK subset, C and C++, and Simulink and Stateflow models. We have accomplished this while addressing the requirements of various safety standards such as DO-178B/C, EN 50128, ECSS-E-ST-40C / ECSS-Q-ST-80C, IEC 61508 and ISO 26262.

by Fabien Chouteau

Ada/SPARK Crate Of The Year 2021 Winners Announced!

In June of 2021 we announced the launch of a new programming competition called Ada/SPARK Crate Of The Year Awards. We believe the Alire source package manager is a game changer for Ada/SPARK, so we want to use this competition to reward the people contributing to the ecosystem. Today we are pleased to announce the results. But first, we want to congratulate all the participants, and the Alire community at large, for reaching 200 crates in the ecosystem in January of this year. We truly believe in a bright future for the Ada/SPARK open-source ecosystem with Alire at the forefront. Reaching this milestone is a great sign, inside and outside the Ada/SPARK community, of the evolution and the energy of the ecosystem.

by Yannick Moy

SPARKNaCl - Two Years of Optimizing Crypto Code in SPARK (and counting)

SPARKNaCl is a SPARK ver­sion of the Tweet­Na­Cl cryp­to­graph­ic library, developed by formal methods and security expert Rod Chapman. For two years now, Rod has been developing and optimizing this open-source cryptographic library while preserving the automatic type-safety proof across code changes and tool updates. He has recently given a talk about this experience that I highly recommend.

#SPARK    #Cryptography    #Formal Verification   

by Paul Butcher

Fuzz Testing in International Aerospace Guidelines

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.

#Fuzzing    #Cyber Security    #Civil Avionics    #DO-356A    #ED-203A   

by Yannick Moy

Enhancing the Security of a TCP Stack with SPARK

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.

#SPARK    #Security    #Formal Verification   

by Pat Rogers

Task Suspension with a Timeout in Ravenscar/Jorvik

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.

#Ada    #Tasking    #Ravenscar    #Jorvik    #Timeouts    #Timing_Event    #Suspension_Object   

by Yannick Moy

When the RISC-V ISA is the Weakest Link

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.

#Security    #SPARK    #RISC-V   

by Kyriakos Georgiou

Security-Hardening Software Libraries with Ada and SPARK

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”.

#SPARK    #STM32    #Embedded   

by Roderick Chapman

SPARKNaCl with GNAT and SPARK Community 2021: Port, Proof and Performance

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.

#SPARK     #Cryptography    #Formal Verification    #Code generation    #RISC-V    #Security   

by Jessie Glockner

Celebrating Women Engineering Heroes - International Women in Engineering Day 2021

Women make up roughly 38% of the global workforce, yet they constitute only 10–20% of the engineering workforce. In the U.S., numbers suggest that 40% of women who graduate with engineering degrees never enter the profession or eventually leave it. Why? The reasons vary but primarily involve socio-economic constraints on women in general, workplace inequities, and lack of support for work-life balance. Sadly, history itself has often failed to properly acknowledge the instrumental contributions of women inventors, scientists, and mathematicians who have helped solve some of our world's toughest challenges. How can young women emulate their successes if they don't even know about them?

by Pat Rogers

An Introduction to Jorvik, the New Tasking Profile in Ada 2022

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.

#Ada Tasking Profiles    #Jorvik    #Ravenscar    #Ada 2022    #Real-Time    #Embedded