Zephyr Project

Projects that follow the best practices below can voluntarily self-certify and show that they've achieved an Open Source Security Foundation (OpenSSF) best practices badge.

There is no set of practices that can guarantee that software will never have defects or vulnerabilities; even formal methods can fail if the specifications or assumptions are wrong. Nor is there any set of practices that can guarantee that a project will sustain a healthy and well-functioning development community. However, following best practices can help improve the results of projects. For example, some practices enable multi-person review before release, which can both help find otherwise hard-to-find technical vulnerabilities and help build trust and a desire for repeated interaction among developers from different companies. To earn a badge, all MUST and MUST NOT criteria must be met, all SHOULD criteria must be met OR be unmet with justification, and all SUGGESTED criteria must be met OR unmet (we want them considered at least). If you want to enter justification text as a generic comment, instead of being a rationale that the situation is acceptable, start the text block with '//' followed by a space. Feedback is welcome via the GitHub site as issues or pull requests There is also a mailing list for general discussion.

We gladly provide the information in several locales, however, if there is any conflict or inconsistency between the translations, the English version is the authoritative version.
If this is your project, please show your badge status on your project page! The badge status looks like this: Badge level for project 74 is gold Here is how to embed it:
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These are the Silver level criteria. You can also view the Passing or Gold level criteria.

        

 Basics 17/17 ●

  • Identification

    Note that other projects may use the same name.

    The Zephyr Project is a small, scalable real-time operating system for use on resource-constrained systems supporting multiple architectures. Developers are able to tailor their optimal solution. As a true open source project, the community can evolve the Zephyr Project to support new hardware, developer tools, sensor and device drivers. Advancements in security, device management capabilities, connectivity stacks and file systems can be easily implemented.

  • Prerequisites


    Enough for a badge!

    The project MUST achieve a passing level badge. [achieve_passing]

  • Basic project website content


    Enough for a badge!

    The information on how to contribute MUST include the requirements for acceptable contributions (e.g., a reference to any required coding standard). (URL required) [contribution_requirements]

    https://docs.zephyrproject.org/latest/contribute/index.html -- Require contributors to adhere to specific coding styles and guidelines outlined in the project documentation.


  • Project oversight


    Enough for a badge!

    The project SHOULD have a legal mechanism where all developers of non-trivial amounts of project software assert that they are legally authorized to make these contributions. The most common and easily-implemented approach for doing this is by using a Developer Certificate of Origin (DCO), where users add "signed-off-by" in their commits and the project links to the DCO website. However, this MAY be implemented as a Contributor License Agreement (CLA), or other legal mechanism. (URL required) [dco]
    The DCO is the recommended mechanism because it's easy to implement, tracked in the source code, and git directly supports a "signed-off" feature using "commit -s". To be most effective it is best if the project documentation explains what "signed-off" means for that project. A CLA is a legal agreement that defines the terms under which intellectual works have been licensed to an organization or project. A contributor assignment agreement (CAA) is a legal agreement that transfers rights in an intellectual work to another party; projects are not required to have CAAs, since having CAA increases the risk that potential contributors will not contribute, especially if the receiver is a for-profit organization. The Apache Software Foundation CLAs (the individual contributor license and the corporate CLA) are examples of CLAs, for projects which determine that the risks of these kinds of CLAs to the project are less than their benefits.

    DCO and signed-off-by expectations are documented in contribution guidelines: https://www.zephyrproject.org/doc/contribute/contribute_guidelines.html and in the GitHub CONTRIBUTING.rst file


    Enough for a badge!

    The project MUST clearly define and document its project governance model (the way it makes decisions, including key roles). (URL required) [governance]
    There needs to be some well-established documented way to make decisions and resolve disputes. In small projects, this may be as simple as "the project owner and lead makes all final decisions". There are various governance models, including benevolent dictator and formal meritocracy; for more details, see Governance models. Both centralized (e.g., single-maintainer) and decentralized (e.g., group maintainers) approaches have been successfully used in projects. The governance information does not need to document the possibility of creating a project fork, since that is always possible for FLOSS projects.

    https://www.zephyrproject.org/about/organization


    Enough for a badge!

    The project MUST adopt a code of conduct and post it in a standard location. (URL required) [code_of_conduct]
    Projects may be able to improve the civility of their community and to set expectations about acceptable conduct by adopting a code of conduct. This can help avoid problems before they occur and make the project a more welcoming place to encourage contributions. This should focus only on behavior within the community/workplace of the project. Example codes of conduct are the Linux kernel code of conduct, the Contributor Covenant Code of Conduct, the Debian Code of Conduct, the Ubuntu Code of Conduct, the Fedora Code of Conduct, the GNOME Code Of Conduct, the KDE Community Code of Conduct, the Python Community Code of Conduct, The Ruby Community Conduct Guideline, and The Rust Code of Conduct.

    Contributing and Conduct guidelines are found https://www.zephyrproject.org/community/community-guidelines


    Enough for a badge!

    The project MUST clearly define and publicly document the key roles in the project and their responsibilities, including any tasks those roles must perform. It MUST be clear who has which role(s), though this might not be documented in the same way. (URL required) [roles_responsibilities]
    The documentation for governance and roles and responsibilities may be in one place.

    also documented at https://www.zephyrproject.org/about/organization


    Enough for a badge!

    The project MUST be able to continue with minimal interruption if any one person dies, is incapacitated, or is otherwise unable or unwilling to continue support of the project. In particular, the project MUST be able to create and close issues, accept proposed changes, and release versions of software, within a week of confirmation of the loss of support from any one individual. This MAY be done by ensuring someone else has any necessary keys, passwords, and legal rights to continue the project. Individuals who run a FLOSS project MAY do this by providing keys in a lockbox and a will providing any needed legal rights (e.g., for DNS names). (URL required) [access_continuity]

    The project has distributed maintainer and codeowner roles, as found in the GitHub repository CODEOWNER files (https://github.com/zephyrproject-rtos/zephyr/blob/master/CODEOWNERS). There are also multiple administrators for the GitHub site that are authorized to merge pull requests, and the development team is spread around the world (Canada, India, multiple US locations).


    Enough for a badge!

    The project SHOULD have a "bus factor" of 2 or more. (URL required) [bus_factor]
    A "bus factor" (aka "truck factor") is the minimum number of project members that have to suddenly disappear from a project ("hit by a bus") before the project stalls due to lack of knowledgeable or competent personnel. The truck-factor tool can estimate this for projects on GitHub. For more information, see Assessing the Bus Factor of Git Repositories by Cosentino et al.

    Using the truck-factor tool, we have a TF of 12, see https://github.com/zephyrproject-rtos/zephyr/wiki/Truck-Factor for the output from the tool.


  • Documentation


    Enough for a badge!

    The project MUST have a documented roadmap that describes what the project intends to do and not do for at least the next year. (URL required) [documentation_roadmap]
    The project might not achieve the roadmap, and that's fine; the purpose of the roadmap is to help potential users and contributors understand the intended direction of the project. It need not be detailed.

    The next 4 planned releases (1 year outlook) are shown here: https://github.com/zephyrproject-rtos/zephyr/projects/9


    Enough for a badge!

    The project MUST include documentation of the architecture (aka high-level design) of the software produced by the project. If the project does not produce software, select "not applicable" (N/A). (URL required) [documentation_architecture]
    A software architecture explains a program's fundamental structures, i.e., the program's major components, the relationships among them, and the key properties of these components and relationships.

    The Zephyr Kernel Primer (https://www.zephyrproject.org/doc/kernel/kernel.html) has an introduction to the kernel's key capabilities and services, along with an overview of the source tree structure.


    Enough for a badge!

    The project MUST document what the user can and cannot expect in terms of security from the software produced by the project (its "security requirements"). (URL required) [documentation_security]
    These are the security requirements that the software is intended to meet.

    https://www.zephyrproject.org/doc/security/security-overview.html outlines the steps of the Zephyr Security board towards a defined security process that helps developers build more secure software while addressing security compliance requirements


    Enough for a badge!

    The project MUST provide a "quick start" guide for new users to help them quickly do something with the software. (URL required) [documentation_quick_start]
    The idea is to show users how to get started and make the software do anything at all. This is critically important for potential users to get started.

    Getting Started guide is here: https://www.zephyrproject.org/doc/getting_started/getting_started.html


    Enough for a badge!

    The project MUST make an effort to keep the documentation consistent with the current version of the project results (including software produced by the project). Any known documentation defects making it inconsistent MUST be fixed. If the documentation is generally current, but erroneously includes some older information that is no longer true, just treat that as a defect, then track and fix as usual. [documentation_current]
    The documentation MAY include information about differences or changes between versions of the software and/or link to older versions of the documentation. The intent of this criterion is that an effort is made to keep the documentation consistent, not that the documentation must be perfect.

    Documentation is maintained and released with each tagged release of the software (e.g., https://www.zephyrproject.org/doc/1.8.0/ for the 1.8 release). Additionally, the master branch documentation is updated and maintained at https://www.zephyrproject.org/doc. Documentation defects are tracked along with code defects in our Jira (soon to be GitHub issues) system.


    Enough for a badge!

    The project repository front page and/or website MUST identify and hyperlink to any achievements, including this best practices badge, within 48 hours of public recognition that the achievement has been attained. (URL required) [documentation_achievements]
    An achievement is any set of external criteria that the project has specifically worked to meet, including some badges. This information does not need to be on the project website front page. A project using GitHub can put achievements on the repository front page by adding them to the README file.

    https://github.com/zephyrproject-rtos/zephyr has the cii best practices badge and the announcement page (https://www.zephyrproject.org/news/announcements) mentions project achievements.


  • Accessibility and internationalization


    Enough for a badge!

    The project (both project sites and project results) SHOULD follow accessibility best practices so that persons with disabilities can still participate in the project and use the project results where it is reasonable to do so. [accessibility_best_practices]
    For web applications, see the Web Content Accessibility Guidelines (WCAG 2.0) and its supporting document Understanding WCAG 2.0; see also W3C accessibility information. For GUI applications, consider using the environment-specific accessibility guidelines (such as Gnome, KDE, XFCE, Android, iOS, Mac, and Windows). Some TUI applications (e.g. `ncurses` programs) can do certain things to make themselves more accessible (such as `alpine`'s `force-arrow-cursor` setting). Most command-line applications are fairly accessible as-is. This criterion is often N/A, e.g., for program libraries. Here are some examples of actions to take or issues to consider:
    • Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language ( WCAG 2.0 guideline 1.1)
    • Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. ( WCAG 2.0 guideline 1.4.1)
    • The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for large text, incidental text, and logotypes ( WCAG 2.0 guideline 1.4.3)
    • Make all functionality available from a keyboard (WCAG guideline 2.1)
    • A GUI or web-based project SHOULD test with at least one screen-reader on the target platform(s) (e.g. NVDA, Jaws, or WindowEyes on Windows; VoiceOver on Mac & iOS; Orca on Linux/BSD; TalkBack on Android). TUI programs MAY work to reduce overdraw to prevent redundant reading by screen-readers.

    Zephyr is an embedded OS without any user interface or textual output. This can come as part of an application on top of Zephyr, but zephyr itself does not have any end-user facing interface that needs to be internationalised.


    Enough for a badge!

    The software produced by the project SHOULD be internationalized to enable easy localization for the target audience's culture, region, or language. If internationalization (i18n) does not apply (e.g., the software doesn't generate text intended for end-users and doesn't sort human-readable text), select "not applicable" (N/A). [internationalization]
    Localization "refers to the adaptation of a product, application or document content to meet the language, cultural and other requirements of a specific target market (a locale)." Internationalization is the "design and development of a product, application or document content that enables easy localization for target audiences that vary in culture, region, or language." (See W3C's "Localization vs. Internationalization".) Software meets this criterion simply by being internationalized. No localization for another specific language is required, since once software has been internationalized it's possible for others to work on localization.

    Zephyr is an embedded OS without any user interface or textual output. This can come as part of an application on top of Zephyr, but zephyr itself does not have any end-user facing interface that needs to be internationalised.


  • Other


    Enough for a badge!

    If the project sites (website, repository, and download URLs) store passwords for authentication of external users, the passwords MUST be stored as iterated hashes with a per-user salt by using a key stretching (iterated) algorithm (e.g., Argon2id, Bcrypt, Scrypt, or PBKDF2). If the project sites do not store passwords for this purpose, select "not applicable" (N/A). [sites_password_security]
    Note that the use of GitHub meets this criterion. This criterion only applies to passwords used for authentication of external users into the project sites (aka inbound authentication). If the project sites must log in to other sites (aka outbound authentication), they may need to store authorization tokens for that purpose differently (since storing a hash would be useless). This applies criterion crypto_password_storage to the project sites, similar to sites_https.

    Website is not available for external users. Github and other services used do use a 2 factor authentication for all contributors.


 Change Control 1/1 ●

  • Previous versions


    Enough for a badge!

    The project MUST maintain the most often used older versions of the product or provide an upgrade path to newer versions. If the upgrade path is difficult, the project MUST document how to perform the upgrade (e.g., the interfaces that have changed and detailed suggested steps to help upgrade). [maintenance_or_update]

    Previous software releases are available from https://www.zephyrproject.org/downloads. A plan for Long-Term-Support (LTS) support is in progress.


 Reporting 3/3 ●

  • Bug-reporting process


    Enough for a badge!

    The project MUST use an issue tracker for tracking individual issues. [report_tracker]

    https://github.com/zephyrproject-rtos/zephyr/issues


  • Vulnerability report process


    Enough for a badge!

    The project MUST give credit to the reporter(s) of all vulnerability reports resolved in the last 12 months, except for the reporter(s) who request anonymity. If there have been no vulnerabilities resolved in the last 12 months, select "not applicable" (N/A). (URL required) [vulnerability_report_credit]

    All changes to software are submitted through the GitHub pull request process and logged and reviewed there: https://github.com/zephyrproject-rtos/zephyr/pulls. Git log tools can be used to generate detailed reports, as well as summaries on https://github.com/zephyrproject-rtos/zephyr/pulse for insights.


    Enough for a badge!

    The project MUST have a documented process for responding to vulnerability reports. (URL required) [vulnerability_response_process]
    This is strongly related to vulnerability_report_process, which requires that there be a documented way to report vulnerabilities. It also related to vulnerability_report_response, which requires response to vulnerability reports within a certain time frame.

    Security-related issue reporting is mentioned on https://www.zephyrproject.org/doc/introduction/introducing_zephyr.html and documented in https://www.zephyrproject.org/doc/security/security-overview.html


 Quality 19/19 ●

  • Coding standards


    Enough for a badge!

    The project MUST identify the specific coding style guides for the primary languages it uses, and require that contributions generally comply with it. (URL required) [coding_standards]
    In most cases this is done by referring to some existing style guide(s), possibly listing differences. These style guides can include ways to improve readability and ways to reduce the likelihood of defects (including vulnerabilities). Many programming languages have one or more widely-used style guides. Examples of style guides include Google's style guides and SEI CERT Coding Standards.

    The project contribution guidelines include coding standards and tools for verifying: https://www.zephyrproject.org/doc/contribute/contribute_guidelines.html#coding-style


    Enough for a badge!

    The project MUST automatically enforce its selected coding style(s) if there is at least one FLOSS tool that can do so in the selected language(s). [coding_standards_enforced]
    This MAY be implemented using static analysis tool(s) and/or by forcing the code through code reformatters. In many cases the tool configuration is included in the project's repository (since different projects may choose different configurations). Projects MAY allow style exceptions (and typically will); where exceptions occur, they MUST be rare and documented in the code at their locations, so that these exceptions can be reviewed and so that tools can automatically handle them in the future. Examples of such tools include ESLint (JavaScript), Rubocop (Ruby), and devtools check (R).

    gitlint and checkpatch tools automatically verify and enforce coding standards, as documented in https://www.zephyrproject.org/doc/contribute/contribute_guidelines.html#coding-style


  • Working build system


    Enough for a badge!

    Build systems for native binaries MUST honor the relevant compiler and linker (environment) variables passed in to them (e.g., CC, CFLAGS, CXX, CXXFLAGS, and LDFLAGS) and pass them to compiler and linker invocations. A build system MAY extend them with additional flags; it MUST NOT simply replace provided values with its own. If no native binaries are being generated, select "not applicable" (N/A). [build_standard_variables]
    It should be easy to enable special build features like Address Sanitizer (ASAN), or to comply with distribution hardening best practices (e.g., by easily turning on compiler flags to do so).

    We're using CMake to generate binaries which does support the above and does honor environment variables.


    Enough for a badge!

    The build and installation system SHOULD preserve debugging information if they are requested in the relevant flags (e.g., "install -s" is not used). If there is no build or installation system (e.g., typical JavaScript libraries), select "not applicable" (N/A). [build_preserve_debug]
    E.G., setting CFLAGS (C) or CXXFLAGS (C++) should create the relevant debugging information if those languages are used, and they should not be stripped during installation. Debugging information is needed for support and analysis, and also useful for measuring the presence of hardening features in the compiled binaries.

    The generated ELF has debugging information, however the binary installed to the final platform may not preserve this information.


    Enough for a badge!

    The build system for the software produced by the project MUST NOT recursively build subdirectories if there are cross-dependencies in the subdirectories. If there is no build or installation system (e.g., typical JavaScript libraries), select "not applicable" (N/A). [build_non_recursive]
    The project build system's internal dependency information needs to be accurate, otherwise, changes to the project may not build correctly. Incorrect builds can lead to defects (including vulnerabilities). A common mistake in large build systems is to use a "recursive build" or "recursive make", that is, a hierarchy of subdirectories containing source files, where each subdirectory is independently built. Unless each subdirectory is fully independent, this is a mistake, because the dependency information is incorrect.

    Any cross dependencies will cause a rebuild of the dependent component.


    Enough for a badge!

    The project MUST be able to repeat the process of generating information from source files and get exactly the same bit-for-bit result. If no building occurs (e.g., scripting languages where the source code is used directly instead of being compiled), select "not applicable" (N/A). [build_repeatable]
    GCC and clang users may find the -frandom-seed option useful; in some cases, this can be resolved by forcing some sort order. More suggestions can be found at the reproducible build site.

    Rebuilding binaries that have no variable data such as timestamps results in the same bit-for-bit output, this is verified by building a binary for a certain configuration multiple times and comparing check-sums of generated binaries and all other output.


  • Installation system


    Enough for a badge!

    The project MUST provide a way to easily install and uninstall the software produced by the project using a commonly-used convention. [installation_common]
    Examples include using a package manager (at the system or language level), "make install/uninstall" (supporting DESTDIR), a container in a standard format, or a virtual machine image in a standard format. The installation and uninstallation process (e.g., its packaging) MAY be implemented by a third party as long as it is FLOSS.

    The build system provides a common method for installing on all target platforms.


    Enough for a badge!

    The installation system for end-users MUST honor standard conventions for selecting the location where built artifacts are written to at installation time. For example, if it installs files on a POSIX system it MUST honor the DESTDIR environment variable. If there is no installation system or no standard convention, select "not applicable" (N/A). [installation_standard_variables]

    We install the compiled image in a platform-specific way (e.g., to flash)


    Enough for a badge!

    The project MUST provide a way for potential developers to quickly install all the project results and support environment necessary to make changes, including the tests and test environment. This MUST be performed with a commonly-used convention. [installation_development_quick]
    This MAY be implemented using a generated container and/or installation script(s). External dependencies would typically be installed by invoking system and/or language package manager(s), per external_dependencies.

    We have getting started guides for Linux, Windows, and MacOS


  • Externally-maintained components


    Enough for a badge!

    The project MUST list external dependencies in a computer-processable way. (URL required) [external_dependencies]
    Typically this is done using the conventions of package manager and/or build system. Note that this helps implement installation_development_quick.

    Note: this is about installation of items that are needed to use and build zephyr, see requirement above.

    External components are identified in the /ext area in GitHub: https://github.com/zephyrproject-rtos/zephyr/tree/master/ext but those are not "installed", they are part of the source. For external dependencies need to build and test the project we have scripts/requirements.txt (https://github.com/zephyrproject-rtos/zephyr/blob/master/scripts/requirements.txt).


    Enough for a badge!

    Projects MUST monitor or periodically check their external dependencies (including convenience copies) to detect known vulnerabilities, and fix exploitable vulnerabilities or verify them as unexploitable. [dependency_monitoring]
    This can be done using an origin analyzer / dependency checking tool / software composition analysis tool such as OWASP's Dependency-Check, Sonatype's Nexus Auditor, Synopsys' Black Duck Software Composition Analysis, and Bundler-audit (for Ruby). Some package managers include mechanisms to do this. It is acceptable if the components' vulnerability cannot be exploited, but this analysis is difficult and it is sometimes easier to simply update or fix the part.

    see https://github.com/zephyrproject-rtos/zephyr/issues/6533, one step of the release process is to verify for known vulnerabilities


    Enough for a badge!

    The project MUST either:
    1. make it easy to identify and update reused externally-maintained components; or
    2. use the standard components provided by the system or programming language.
    Then, if a vulnerability is found in a reused component, it will be easy to update that component. [updateable_reused_components]
    A typical way to meet this criterion is to use system and programming language package management systems. Many FLOSS programs are distributed with "convenience libraries" that are local copies of standard libraries (possibly forked). By itself, that's fine. However, if the program *must* use these local (forked) copies, then updating the "standard" libraries as a security update will leave these additional copies still vulnerable. This is especially an issue for cloud-based systems; if the cloud provider updates their "standard" libaries but the program won't use them, then the updates don't actually help. See, e.g., "Chromium: Why it isn't in Fedora yet as a proper package" by Tom Callaway.

    External components are self-contained without any modifications or local changes, we maintain information about the source and origin of such components and track the used versions and SHAs in case of git repositories. Updating to a new component is in most cases a drop-in replacement of existing code. We will support external components in external repos. Additional, wherever we have local modifications, we maintain a fork of the original trees and keep the trees up-to-date with upstream. Local modification are submitted upstream where applicable, this is a policy of the project.


    Enough for a badge!

    The project SHOULD avoid using deprecated or obsolete functions and APIs where FLOSS alternatives are available in the set of technology it uses (its "technology stack") and to a supermajority of the users the project supports (so that users have ready access to the alternative). [interfaces_current]

    The project is self-contained and does use minimal external APIS, mostly from libc. We verify usage of those APIs on constant basis and remove any obsolete usage when found or reported.


  • Automated test suite


    Enough for a badge!

    An automated test suite MUST be applied on each check-in to a shared repository for at least one branch. This test suite MUST produce a report on test success or failure. [automated_integration_testing]
    This requirement can be viewed as a subset of test_continuous_integration, but focused on just testing, without requiring continuous integration.

    Each commit/Pull Request requires passing a series of sanity checks, including building documentation, driven by the "shippable" tool: https://app.shippable.com/github/zephyrproject-rtos/zephyr/dashboard


    Enough for a badge!

    The project MUST add regression tests to an automated test suite for at least 50% of the bugs fixed within the last six months. [regression_tests_added50]

    Issues that are marked with regression label (https://github.com/zephyrproject-rtos/zephyr/labels/Regression) will be added to automated test-suite and integration tests that run through CI where applicable.


    Enough for a badge!

    The project MUST have FLOSS automated test suite(s) that provide at least 80% statement coverage if there is at least one FLOSS tool that can measure this criterion in the selected language. [test_statement_coverage80]
    Many FLOSS tools are available to measure test coverage, including gcov/lcov, Blanket.js, Istanbul, JCov, and covr (R). Note that meeting this criterion is not a guarantee that the test suite is thorough, instead, failing to meet this criterion is a strong indicator of a poor test suite.

    We use gcov/lcov to measure coverage of core features of the project. Due to the fact that Zephyr is an RTOS that can't be run with all features enabled on a host system, the coverage of some areas is not measured yet, the kernel however is being measured and has coverage of 80% in the supported configuration and where measurement is possible. Coverage reports can be found here: https://codecov.io/gh/zephyrproject-rtos/zephyr


  • New functionality testing


    Enough for a badge!

    The project MUST have a formal written policy that as major new functionality is added, tests for the new functionality MUST be added to an automated test suite. [test_policy_mandated]

    Policy for adding new functionality and the requirements on tests can be seen here: https://github.com/zephyrproject-rtos/zephyr/blob/master/CONTRIBUTING.rst


    Enough for a badge!

    The project MUST include, in its documented instructions for change proposals, the policy that tests are to be added for major new functionality. [tests_documented_added]
    However, even an informal rule is acceptable as long as the tests are being added in practice.

    https://github.com/zephyrproject-rtos/zephyr/blob/main/CONTRIBUTING.rst


  • Warning flags


    Enough for a badge!

    Projects MUST be maximally strict with warnings in the software produced by the project, where practical. [warnings_strict]
    Some warnings cannot be effectively enabled on some projects. What is needed is evidence that the project is striving to enable warning flags where it can, so that errors are detected early.

    Build system statically compiles and fails when met with warnings. CI also catch potential issues before being accepted into the code.


 Security 13/13 ●

  • Secure development knowledge


    Enough for a badge!

    The project MUST implement secure design principles (from "know_secure_design"), where applicable. If the project is not producing software, select "not applicable" (N/A). [implement_secure_design]
    For example, the project results should have fail-safe defaults (access decisions should deny by default, and projects' installation should be secure by default). They should also have complete mediation (every access that might be limited must be checked for authority and be non-bypassable). Note that in some cases principles will conflict, in which case a choice must be made (e.g., many mechanisms can make things more complex, contravening "economy of mechanism" / keep it simple).

    http://docs.zephyrproject.org/security/secure-coding.html


  • Use basic good cryptographic practices

    Note that some software does not need to use cryptographic mechanisms. If your project produces software that (1) includes, activates, or enables encryption functionality, and (2) might be released from the United States (US) to outside the US or to a non-US-citizen, you may be legally required to take a few extra steps. Typically this just involves sending an email. For more information, see the encryption section of Understanding Open Source Technology & US Export Controls.

    Enough for a badge!

    The default security mechanisms within the software produced by the project MUST NOT depend on cryptographic algorithms or modes with known serious weaknesses (e.g., the SHA-1 cryptographic hash algorithm or the CBC mode in SSH). [crypto_weaknesses]
    Concerns about CBC mode in SSH are discussed in CERT: SSH CBC vulnerability.

    There are no default usages for weak crypto, SSH is not being used and is not supported.


    Enough for a badge!

    The project SHOULD support multiple cryptographic algorithms, so users can quickly switch if one is broken. Common symmetric key algorithms include AES, Twofish, and Serpent. Common cryptographic hash algorithm alternatives include SHA-2 (including SHA-224, SHA-256, SHA-384 AND SHA-512) and SHA-3. [crypto_algorithm_agility]

    Through the support of mbedTLS and tinyCrypt, users and developers have a variety of algorithms to choose from.


    Enough for a badge!

    The project MUST support storing authentication credentials (such as passwords and dynamic tokens) and private cryptographic keys in files that are separate from other information (such as configuration files, databases, and logs), and permit users to update and replace them without code recompilation. If the project never processes authentication credentials and private cryptographic keys, select "not applicable" (N/A). [crypto_credential_agility]

    This is application specific and is out of scope for the project. Mechanism to support this requirement are provided in general terms. Application developer will have to follow best practices for their use-case.


    Enough for a badge!

    The software produced by the project SHOULD support secure protocols for all of its network communications, such as SSHv2 or later, TLS1.2 or later (HTTPS), IPsec, SFTP, and SNMPv3. Insecure protocols such as FTP, HTTP, telnet, SSLv3 or earlier, and SSHv1 SHOULD be disabled by default, and only enabled if the user specifically configures it. If the software produced by the project does not support network communications, select "not applicable" (N/A). [crypto_used_network]

    We support TLS and DTLS for all communication protocols. HTTPS, COAPS and any other protocols can be abled with additional security enabled.


    Enough for a badge!

    The software produced by the project SHOULD, if it supports or uses TLS, support at least TLS version 1.2. Note that the predecessor of TLS was called SSL. If the software does not use TLS, select "not applicable" (N/A). [crypto_tls12]

    All configurations of the project use TLS 12 by default:

    lib/crypto/mbedtls/configs/config-ccm-psk-tls1_2.h:#define MBEDTLS_SSL_PROTO_TLS1_2 ext/lib/crypto/mbedtls/configs/config-coap.h:#define MBEDTLS_SSL_PROTO_TLS1_2 ext/lib/crypto/mbedtls/configs/config-mini-dtls1_2.h:#define MBEDTLS_SSL_PROTO_TLS1_2 ext/lib/crypto/mbedtls/configs/config-mini-tls1_2.h:#define MBEDTLS_SSL_PROTO_TLS1_2 ext/lib/crypto/mbedtls/configs/config-threadnet.h:#define MBEDTLS_SSL_PROTO_TLS1_2

    https://github.com/zephyrproject-rtos/zephyr/tree/master/ext/lib/crypto/mbedtls/configs


    Enough for a badge!

    The software produced by the project MUST, if it supports TLS, perform TLS certificate verification by default when using TLS, including on subresources. If the software does not use TLS, select "not applicable" (N/A). [crypto_certificate_verification]
    Note that incorrect TLS certificate verification is a common mistake. For more information, see "The Most Dangerous Code in the World: Validating SSL Certificates in Non-Browser Software" by Martin Georgiev et al. and "Do you trust this application?" by Michael Catanzaro.

    The project contains a sample application that is located at the primary repository located at: https://github.com/zephyrproject-rtos/zephyr The sample application implements a proper TLS secure connection and publishes data to the Google Cloud.


    Enough for a badge!

    The software produced by the project MUST, if it supports TLS, perform certificate verification before sending HTTP headers with private information (such as secure cookies). If the software does not use TLS, select "not applicable" (N/A). [crypto_verification_private]

    The project contains a sample application that is located at the primary repository located at: https://github.com/zephyrproject-rtos/zephyr The sample application implements a proper TLS secure connection and publishes data to the Google Cloud.


  • Secure release


    Enough for a badge!

    The project MUST cryptographically sign releases of the project results intended for widespread use, and there MUST be a documented process explaining to users how they can obtain the public signing keys and verify the signature(s). The private key for these signature(s) MUST NOT be on site(s) used to directly distribute the software to the public. If releases are not intended for widespread use, select "not applicable" (N/A). [signed_releases]
    The project results include both source code and any generated deliverables where applicable (e.g., executables, packages, and containers). Generated deliverables MAY be signed separately from source code. These MAY be implemented as signed git tags (using cryptographic digital signatures). Projects MAY provide generated results separately from tools like git, but in those cases, the separate results MUST be separately signed.

    We don't do binary distributions and Git provides a secure release history.


    Enough for a badge!

    It is SUGGESTED that in the version control system, each important version tag (a tag that is part of a major release, minor release, or fixes publicly noted vulnerabilities) be cryptographically signed and verifiable as described in signed_releases. [version_tags_signed]

    Starting with release 1.12, the releases are now being signed by keys of recognized developers & maintainers.


  • Other security issues


    Enough for a badge!

    The project results MUST check all inputs from potentially untrusted sources to ensure they are valid (an *allowlist*), and reject invalid inputs, if there are any restrictions on the data at all. [input_validation]
    Note that comparing input against a list of "bad formats" (aka a *denylist*) is normally not enough, because attackers can often work around a denylist. In particular, numbers are converted into internal formats and then checked if they are between their minimum and maximum (inclusive), and text strings are checked to ensure that they are valid text patterns (e.g., valid UTF-8, length, syntax, etc.). Some data may need to be "anything at all" (e.g., a file uploader), but these would typically be rare.

    The project does not have user interfaces that would allow user input by default, so this is out of scope. If those interfaces are added by the developer/user they need to follow our secure coding practices document in the project here: http://docs.zephyrproject.org/security/security.html


    Enough for a badge!

    Hardening mechanisms SHOULD be used in the software produced by the project so that software defects are less likely to result in security vulnerabilities. [hardening]
    Hardening mechanisms may include HTTP headers like Content Security Policy (CSP), compiler flags to mitigate attacks (such as -fstack-protector), or compiler flags to eliminate undefined behavior. For our purposes least privilege is not considered a hardening mechanism (least privilege is important, but separate).

    We do build by default with -Wformat -Wformat-security -Wno-format-zero-length and stack-protector is enabled as an option where supported. It is disabled by default for performance reasons but can be enabled by the user. The master CMake file contents show this to be the case:

    https://github.com/zephyrproject-rtos/zephyr/blob/master/CMakeLists.txt


    Enough for a badge!

    The project MUST provide an assurance case that justifies why its security requirements are met. The assurance case MUST include: a description of the threat model, clear identification of trust boundaries, an argument that secure design principles have been applied, and an argument that common implementation security weaknesses have been countered. (URL required) [assurance_case]
    An assurance case is "a documented body of evidence that provides a convincing and valid argument that a specified set of critical claims regarding a system’s properties are adequately justified for a given application in a given environment" ("Software Assurance Using Structured Assurance Case Models", Thomas Rhodes et al, NIST Interagency Report 7608). Trust boundaries are boundaries where data or execution changes its level of trust, e.g., a server's boundaries in a typical web application. It's common to list secure design principles (such as Saltzer and Schroeer) and common implementation security weaknesses (such as the OWASP top 10 or CWE/SANS top 25), and show how each are countered. The BadgeApp assurance case may be a useful example. This is related to documentation_security, documentation_architecture, and implement_secure_design.

    The project maintains documentation of current threat models, identification of assets, and trust boundaries. The documentation also provides coding and development guidelines intended to mitigate threats.

    See: https://docs.zephyrproject.org/latest/security/secure-coding.html


 Analysis 2/2 ●

  • Static code analysis


    Enough for a badge!

    The project MUST use at least one static analysis tool with rules or approaches to look for common vulnerabilities in the analyzed language or environment, if there is at least one FLOSS tool that can implement this criterion in the selected language. [static_analysis_common_vulnerabilities]
    Static analysis tools that are specifically designed to look for common vulnerabilities are more likely to find them. That said, using any static tools will typically help find some problems, so we are suggesting but not requiring this for the 'passing' level badge.

    Coverity (https://www.synopsys.com/software-integrity/security-testing/static-analysis-sast.html) is used for static code analysis.


  • Dynamic code analysis


    Enough for a badge!

    If the software produced by the project includes software written using a memory-unsafe language (e.g., C or C++), then at least one dynamic tool (e.g., a fuzzer or web application scanner) MUST be routinely used in combination with a mechanism to detect memory safety problems such as buffer overwrites. If the project does not produce software written in a memory-unsafe language, choose "not applicable" (N/A). [dynamic_analysis_unsafe]
    Examples of mechanisms to detect memory safety problems include Address Sanitizer (ASAN) (available in GCC and LLVM), Memory Sanitizer, and valgrind. Other potentially-used tools include thread sanitizer and undefined behavior sanitizer. Widespread assertions would also work.

    Software is not application-level.



This data is available under the Creative Commons Attribution version 3.0 or later license (CC-BY-3.0+). All are free to share and adapt the data, but must give appropriate credit. Please credit Brett Preston and the OpenSSF Best Practices badge contributors.

Project badge entry owned by: Brett Preston.
Entry created on 2016-03-10 17:42:23 UTC, last updated on 2024-06-05 17:27:55 UTC. Last lost passing badge on 2018-03-10 20:49:56 UTC. Last achieved passing badge on 2018-03-10 20:50:26 UTC.

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