tartufo 0.0.2

tartufo is a tool for scanning git repositories for secrets/passwords/high-entropy data

tartufo

Searches through git repositories for secrets, digging deep into commit history and branches. This is effective at finding secrets accidentally committed. tartufo also can be used by git pre-commit scripts to screen changes for secrets before they are committed to the repository.

Features

tartufo offers the following features:

Regex Checking

tartufo previously functioned by running entropy checks on git diffs. This functionality still exists, but high signal regex checks have been added, and the ability to surpress entropy checking has also been added.

This performs only regular expression checking:

tartufo --regex --entropy=False https://github.com/godaddy/tartufo.git

while this checks only for patterns with high entropy:

tartufo file:///user/godaddy/codeprojects/tartufo/

Specifying either --regex or --entropy without a value implies =True; if these arguments are missing, the default behavior is to perform entropy checking but not regex checking.

If all types of checking are disabled, a RuntimeError exception is raised. It is presumed that the caller did not intend to request an operation that scans nothing.

Limiting Scans by Path

With the --include_paths and --exclude_paths options, it is also possible to limit scanning to a subset of objects in the Git history by defining regular expressions (one per line) in a file to match the targeted object paths. To illustrate, see the example include and exclude files below:

include-patterns.txt:

src/
# lines beginning with "#" are treated as comments and are ignored
gradle/
# regexes must match the entire path, but can use python's regex syntax for
# case-insensitive matching and other advanced options
(?i).*\.(properties|conf|ini|txt|y(a)?ml)$
(.*/)?id_[rd]sa$

exclude-patterns.txt:

(.*/)?\.classpath$
.*\.jmx$
(.*/)?test/(.*/)?resources/

These filter files could then be applied by:

tartufo --include_paths include-patterns.txt --exclude_paths exclude-patterns.txt file://path/to/my/repo.git

With these filters, issues found in files in the root-level src directory would be reported, unless they had the .classpath or .jmx extension, or if they were found in the src/test/dev/resources/ directory, for example. Additional usage information is provided when calling tartufo with the -h or --help options.

These features help cut down on noise, and makes the tool easier to shove into a devops pipeline.

Specifying Repositories

Normally, the URL of the repository to scan is supplied on the command line:

tartufo https://github.com/godaddy/tartufo.git

When invoked in this way, tartufo clones the repository to a scratch directory, scans the local clone, and then deletes it. If a local repository clone already exists, it can be scanned directly:

tartufo --repo_path /my/local/clone

If both --repo_path and a URL are supplied, the URL is ignored and the specified local clone is scanned. If neither is provided, a SyntaxError exception is raised.

Pre-Commit Scans

The --pre_commit flag instructs tartufo to scan staged, uncommitted changes in a local repository. The repository location can be specified using --repo_path, but it is legal to not supply a location; in this case, the caller's current working directory is assumed to be somewhere within the local clone's tree and the repository root is determined automatically.

The following example demonstrates how tartufo can be used to verify secrets will not be committed to a git repository in error:

.git/hooks/pre-commit:

#!/bin/sh

# Redirect output to stderr.
exec 1>&2

# Check for suspicious content.
tartufo --pre_commit --regex --entropy

Git will execute tartufo before committing any content. If problematic changes are detected, they are reported by tartufo and git aborts the commit process. Only when tartufo returns a success status (indicating no potential secrets were discovered) will git commit the staged changes.

Note that it is always possible, although not recommended, to bypass the pre-commit hook by using git commit --no-verify.

If you would like to automate these hooks, you can use the pre-commit tool by adding a .pre-commit-config.yaml file to your repository similar to the following:

- repo: https://github.com/godaddy/tartufo
  rev: master
  hooks:
  - id: tartufo

That's it! Now your contributors only need to run pre-commit install --install-hooks, and tartufo will automatically be run as a pre-commit hook.

Temporary file cleanup

tartufo stores the results in temporary files, which are left on disk by default, to allow inspection if problems are found. To automatically delete these files when tartufo completes, specify the --cleanup flag:

tartufo --cleanup

Install

pip install tartufo

Customizing

Custom regexes can be added with the following flag --rules /path/to/rules. This should be a json file of the following format:

{
    "RSA private key": "-----BEGIN EC PRIVATE KEY-----"
}

Things like subdomain enumeration, s3 bucket detection, and other useful regexes highly custom to the situation can be added.

Normally, the custom regexes are added to the default regexes. If the default regexes should not be included, add the following flag: --default-regexes=False

Feel free to also contribute high signal regexes upstream that you think will benefit the community. Things like Azure keys, Twilio keys, Google Compute keys, are welcome, provided a high signal regex can be constructed.

tartufo's base rule set sources from https://github.com/dxa4481/truffleHogRegexes/blob/master/truffleHogRegexes/regexes.json

How it works

This module will go through the entire commit history of each branch, and check each diff from each commit, and check for secrets. This is both by regex and by entropy. For entropy checks, tartufo will evaluate the shannon entropy for both the base64 char set and hexidecimal char set for every blob of text greater than 20 characters comprised of those character sets in each diff. If at any point a high entropy string >20 characters is detected, it will print to the screen.

Help

usage: tartufo [-h] [--json] [--rules RULES...] [--entropy [BOOLEAN]]
                  [--git-rules-repo REPO_PATH] [--git-rules RULES...]
                  [--regex [BOOLEAN]] [--since_commit SINCE_COMMIT]
                  [--default-regexes [BOOLEAN]]
                  [--max_depth MAX_DEPTH] [--branch BRANCH]
                  [-i INCLUDE_PATHS_FILE] [-x EXCLUDE_PATHS_FILE]
                  [--repo_path REPO_PATH] [--cleanup] [--pre_commit]
                  [git_url]

Find secrets hidden in the depths of git.

positional arguments:
  git_url               repository URL for secret searching

optional arguments:
  -h, --help            show this help message and exit
  --json                Output in JSON
  --rules RULES         One or more json files containing custom regexes
  --git-rules-repo REPO_PATH
                        Path to git repo that contains externally-specified rules
  --git-rules RULES     Relative path(s) to one or more json files in git-rules-repo
  --entropy [BOOLEAN]   Enable entropy checks [default: True]
  --regex [BOOLEAN]     Enable high signal regex checks [default: False]
  --default-regexes [BOOLEAN]
                        When --rules is specified, whether to include the default regexes as well [default: True] 
  --since_commit SINCE_COMMIT
                        Only scan from a given commit hash
  --max_depth MAX_DEPTH
                        The max commit depth to go back when searching for
                        secrets
  --branch BRANCH       Name of the branch to be scanned
  -i INCLUDE_PATHS_FILE, --include_paths INCLUDE_PATHS_FILE
                        File with regular expressions (one per line), at least
                        one of which must match a Git object path in order for
                        it to be scanned; lines starting with "#" are treated
                        as comments and are ignored. If empty or not provided
                        (default), all Git object paths are included unless
                        otherwise excluded via the --exclude_paths option.
  -x EXCLUDE_PATHS_FILE, --exclude_paths EXCLUDE_PATHS_FILE
                        File with regular expressions (one per line), none of
                        which may match a Git object path in order for it to
                        be scanned; lines starting with "#" are treated as
                        comments and are ignored. If empty or not provided
                        (default), no Git object paths are excluded unless
                        effectively excluded via the --include_paths option.
  --repo_path REPO_PATH
                        Path to local repo clone. If provided, git_url will
                        not be used
  --cleanup             Clean up all temporary result files
  --pre_commit          Scan staged files in local repo clone

Contributing

First of all, thank you for considering contributing to tartufo! Before diving head first into the code, please take a moment to familiarize yourself with a few quick guidelines:

• When writing code, please try to match surrounding code style as closely as possible.

• When writing documentation, please write in plain English, following the conventions followed elsewhere in the project.

• New code should be covered by unit tests, where applicable. This could mean existing unit tests but, in the case that it does not, we ask that you write new unit tests to cover the code.

• It is highly recommended that you work on this project inside of an isolated Python virtual environment. This can be set up, along with all necessary Python libraries, via the following commands:

  > python -m venv .venv
  > source .venv/bin/activate
  > pip install -e .[tests]
  

• This project support multiple Python versions in this project. Thus, we ask that you use the tox tool to test against them. If you do not have all of the supported Python versions, that's perfectly okay. They will all be tested against by our CI process. But keep in mind that this may delay the adoption of your contribution, if those tests don't all pass.

• This project uses multiple pre-commit hooks to help ensure our code quality. If you have followed the instructions above for setting up your virtual environment, pre-commit will already be installed, and you only need to run the following:

  > pre-commit install --install-hooks
  

  Now, any time you make a new commit to the repository, you will see something like the following:

  Tartufo..................................................................Passed
  mypy.....................................................................Passed
  flake8...................................................................Passed
  pylint...................................................................Passed
  

• Finally, all changes must be proposed via a pull request on GitHub, which must reviewed and approved by at least one core contributor, before being merged.

Attributions

This project was inspired by and built off of the work done by Dylan Ayrey on the truffleHog project.