Cheese

A Certificate Transparency log configuration and deployment tool for Google's [TesseraCT] implementation. It tries to look and feel a little like the one provided by [Sunlight].

Configuration Generator

The tesseract/genconf tool generates CT log configuration files and keys from a YAML specification in a very similar way to Sunlight.

Usage

1. Build the tool:

go build -o tesseract-genconf ./tesseract/genconf/

2. Create YAML configuration file:

listen:
  - "[::]:8080"
roots: /etc/tesseract/roots.pem
logs:
  - shortname: example2025h1
    listen: "[::]:16900"
    inception: 2025-01-01
    submissionprefix: https://example2025h1.log.ct.example.com
    monitoringprefix: https://example2025h1.mon.ct.example.com
    extraroots: /etc/tesseract/extra-roots.pem
    secret: /etc/tesseract/keys/example2025h1.pem
    localdirectory: /var/lib/tesseract/example2025h1/data
    notafterstart: 2025-01-01T00:00:00Z
    notafterlimit: 2025-07-01T00:00:00Z

3. Generate private keys:

mkdir -p /etc/tesseract/keys
./tesseract-genconf -c config.yaml --write gen-key

4. Create directories and generate environment files:

mkdir -p /var/lib/tesseract/example2025h1/data
./tesseract-genconf -c config.yaml --write gen-env

5. Generate HTML and JSON files:

./tesseract-genconf -c config.yaml --write gen-html

6. Generate nginx configuration files:

./tesseract-genconf -c config.yaml --write gen-nginx

The port from the main listen: field will be used in the NGINX server blocks (in our case :8080). You can symlink the generated $monitoringprefix.conf files from /etc/nginx/sites-enabled/.

7. Generate root certificates (optional):

# For testing/staging environment, take the ccadb 'testing' roots
./tesseract-genconf gen-roots --source https://rennet2027h2.log.ct.ipng.ch/ --output roots-staging.pem

# For production environment, take the ccadb 'production' roots
./tesseract-genconf gen-roots --source https://gouda2027h2.log.ct.ipng.ch/ --output roots-production.pem

Safe File Operations with --diff and --write

The tesseract-genconf tool includes safety features to prevent accidental file modifications:

• --diff: Shows colored unified diffs of what would change without writing files
• --write: Required flag to actually write files to disk
• --no-color: Disables colored diff output (useful for redirecting to files)

Recommended workflow:

# 1. First, preview changes with --diff
./tesseract-genconf -c config.yaml --diff gen-html

# 2. Review the colored diff output, then apply changes
./tesseract-genconf -c config.yaml --write gen-html

# 3. Or combine both to see diffs and write files
./tesseract-genconf -c config.yaml --diff --write gen-html

Note: Flags must come before the command name (e.g., --diff gen-html, not gen-html --diff).