Code Credential Scanner: scan a large, diverse codebase for hard-coded credentials, or credentials present in configuration files

by do son · Published August 2, 2023 · Updated August 2, 2023

Code Credential Scanner

This script is intended to scan a large, diverse codebase for hard-coded credentials, or credentials present in configuration files. These represent a serious security issue and can be extremely hard to detect and manage.

The specific focus of this script is to create a tool that can be used directly by dev teams in a CI/CD pipeline, to manage the remediation process for this issue by alerting the team when credentials are present in the code so that the team can immediately fix issues as they arise.

It is possible to apply to the tool as a point-in-time scanner for this issue, but – since credentials are likely to work their way back into the codebase over time – we strongly advise integration of the script into the CI/CD process, automated build mechanism, or whatever another regularly scheduled automated scanning process the team carries out.

The script is written with the following aims in mind:

Be language agnostic, regular-expression based, and require no parsing, so that it works on any codebase
Reduce false positives wherever possible, even at the (inevitable) cost of false negatives
Provide multiple, straightforward methods for suppressing issues, compatible with other SAST tools
Be concise, simple, and performant

Suppression comments

The script attempts to provide some compatibility with other popular SAST tools.

Text at or near the start of a file ‘# noqa file’ will suppress reporting of any further issues in that file, as will the text ‘flake8: noqa’.

Text on an individual line of ‘# noqa’ will suppress reporting of issues on that line. Many other common suppression comments will also work; the current list is:

        # noinspection

        # noqa

        #noqa

        @SuppressWarnings

        DevSkim

        NOLINT

        NOSONAR

        checkmarx

        coverity

        fortify

        noinspection

        nosec

        safesql

        veracode

We also recommend the use of the comment ‘# noqa cred’, to make it clear to team members that it is specifically the presence of a credential that is the reason for the false positive. Many of the tools referenced here (e.g. devskim) make use of specific error codes relating to tooling relevant to the language or platform in use, that serve the same purpose. It’s possible for the same line of code to have multiple errors of different types.

We caution that it is extremely bad practice to suppress an alert from a SAST tool that is a true positive. It is good practice to periodically review the SAST/lint suppression comments in a codebase to ensure that no ‘true positives’ have been suppressed.

The ‘-nosuppress’ command line flag causes the script to ignore all suppression comments.