FLOSS Best Practices Criteria (Gold Badge)

This is the set of best practices for Free/Libre and Open Source Software (FLOSS) projects to achieve the Open Source Security Foundation (OpenSSF) Best Practices gold badge. You can show this list with just the criteria or with additional information. The full set of criteria are also available.

See criteria discussion for more information about these criteria.

Gold

Basics

Prerequisites

Project oversight

  • The project MUST have a "bus factor" of 2 or more. {Met URL} [bus_factor]
  • The project MUST have at least two unassociated significant contributors. {Met URL} [contributors_unassociated]
    Details:
    Contributors are associated if they are paid to work by the same organization (as an employee or contractor) and the organization stands to benefit from the project's results. Financial grants do not count as being from the same organization if they pass through other organizations (e.g., science grants paid to different organizations from a common government or NGO source do not cause contributors to be associated). Someone is a significant contributor if they have made non-trivial contributions to the project in the past year. Examples of good indicators of a significant contributor are: written at least 1,000 lines of code, contributed 50 commits, or contributed at least 20 pages of documentation.

Other

  • The project MUST include a copyright statement in each source file, identifying the copyright holder (e.g., the [project name] contributors). {Met justification} [copyright_per_file]
    Details:
    This MAY be done by including the following inside a comment near the beginning of each file: "Copyright the [project name] contributors.". See "Copyright Notices in Open Source Software Projects" by Steve Winslow.
  • The project MUST include a license statement in each source file. This MAY be done by including the following inside a comment near the beginning of each file: SPDX-License-Identifier: [SPDX license expression for project]. {Met justification} [license_per_file]
    Details:
    This MAY also be done by including a statement in natural language identifying the license. The project MAY also include a stable URL pointing to the license text, or the full license text. Note that the criterion license_location requires the project license be in a standard location. See this SPDX tutorial for more information about SPDX license expressions. Note the relationship with copyright_per_file, whose content would typically precede the license information.

Change Control

Public version-controlled source repository

  • The project's source repository MUST use a common distributed version control software (e.g., git or mercurial). {Met justification} [repo_distributed]
  • The project MUST clearly identify small tasks that can be performed by new or casual contributors. {Met URL} [small_tasks]
    Details:
    This identification is typically done by marking selected issues in an issue tracker with one or more tags the project uses for the purpose, e.g., up-for-grabs, first-timers-only, "Small fix", microtask, or IdealFirstBug. These new tasks need not involve adding functionality; they can be improving documentation, adding test cases, or anything else that aids the project and helps the contributor understand more about the project.
  • The project MUST require two-factor authentication (2FA) for developers for changing a central repository or accessing sensitive data (such as private vulnerability reports). This 2FA mechanism MAY use mechanisms without cryptographic mechanisms such as SMS, though that is not recommended. {Met justification} [require_2FA]
  • The project's two-factor authentication (2FA) SHOULD use cryptographic mechanisms to prevent impersonation. Short Message Service (SMS) based 2FA, by itself, does NOT meet this criterion, since it is not encrypted. {Met justification} [secure_2FA]
    Details:
    A 2FA mechanism that meets this criterion would be a Time-based One-Time Password (TOTP) application that automatically generates an authentication code that changes after a certain period of time. Note that GitHub supports TOTP.

Quality

Coding standards

  • The project MUST document its code review requirements, including how code review is conducted, what must be checked, and what is required to be acceptable. {N/A justification} {Met URL} [code_review_standards]
    Details:
    See also two_person_review and contribution_requirements.
  • The project MUST have at least 50% of all proposed modifications reviewed before release by a person other than the author, to determine if it is a worthwhile modification and free of known issues which would argue against its inclusion {Met justification} [two_person_review]

Working build system

  • The project MUST have a reproducible build. If no building occurs (e.g., scripting languages where the source code is used directly instead of being compiled), select "not applicable" (N/A). {N/A justification} {Met URL} [build_reproducible]
    Details:
    A reproducible build means that multiple parties can independently redo the process of generating information from source files and get exactly the same bit-for-bit result. In some cases, this can be resolved by forcing some sort order. JavaScript developers may consider using npm shrinkwrap and webpack OccurenceOrderPlugin. GCC and clang users may find the -frandom-seed option useful. The build environment (including the toolset) can often be defined for external parties by specifying the cryptographic hash of a specific container or virtual machine that they can use for rebuilding. The reproducible builds project has documentation on how to do this.

Automated test suite

  • A test suite MUST be invocable in a standard way for that language. {Met URL} [test_invocation]
  • The project MUST implement continuous integration, where new or changed code is frequently integrated into a central code repository and automated tests are run on the result. {Met URL} [test_continuous_integration]
    Details:
    In most cases this means that each developer who works full-time on the project integrates at least daily.
  • The project MUST have FLOSS automated test suite(s) that provide at least 90% statement coverage if there is at least one FLOSS tool that can measure this criterion in the selected language. {N/A justification} {Met justification} [test_statement_coverage90]
  • The project MUST have FLOSS automated test suite(s) that provide at least 80% branch coverage if there is at least one FLOSS tool that can measure this criterion in the selected language. {N/A justification} {Met justification} [test_branch_coverage80]

Security

Use basic good cryptographic practices

  • The software produced by the project MUST 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 MUST 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). {N/A allowed} {Met justification} [crypto_used_network]
  • The software produced by the project MUST, 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). {N/A allowed} {Met justification} [crypto_tls12]

Secured delivery against man-in-the-middle (MITM) attacks

  • The project website, repository (if accessible via the web), and download site (if separate) MUST include key hardening headers with nonpermissive values. {Met URL} [hardened_site]
    Details:
    Note that GitHub and GitLab are known to meet this. Sites such as https://securityheaders.com/ can quickly check this. The key hardening headers are: Content Security Policy (CSP), HTTP Strict Transport Security (HSTS), X-Content-Type-Options (as "nosniff"), and X-Frame-Options. Fully static web sites with no ability to log in via the web pages could omit some hardening headers with less risk, but there's no reliable way to detect such sites, so we require these headers even if they are fully static sites.

Other security issues

  • The project MUST have performed a security review within the last 5 years. This review MUST consider the security requirements and security boundary. {Met justification} [security_review]
    Details:
    This MAY be done by the project members and/or an independent evaluation. This evaluation MAY be supported by static and dynamic analysis tools, but there also must be human review to identify problems (particularly in design) that tools cannot detect.
  • Hardening mechanisms MUST be used in the software produced by the project so that software defects are less likely to result in security vulnerabilities. {N/A justification} {Met URL} [hardening]

Analysis

Dynamic code analysis

  • The project MUST apply at least one dynamic analysis tool to any proposed major production release of the software produced by the project before its release. {N/A justification} {Met justification} [dynamic_analysis]
  • The project SHOULD include many run-time assertions in the software it produces and check those assertions during dynamic analysis. {N/A justification} {Met justification} [dynamic_analysis_enable_assertions]