secrets.cr

Provides encrypted key-value stores that can be registered, saved, and loaded by name. Can be used to securely store environment-specific secrets directly in your repo.

Secrets are encrypted using AES-256 in CBC mode with a nonce and saved IV-first followed by the encrypted text.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     secrets:
       github: sam0x17/secrets.cr
   

2. Run shards install

3. add the following to your .gitignore to ensure encryption keys are not committed by accident:

# .gitignore
.*_secret_key

Usage

require "secrets"

# creates default stores named staging and production
Secrets.register(:staging, create: true)
Secrets.register(:production, create: true)

Secrets[:staging][:API_KEY] = "555-555-ASDF-445"
Secrets[:staging]["some other key"] = "8j98ajsdf"
Secrets[:production][:something] = "something else"

# writes encryption key to .staging_secret_key and encrypted
# secrets to secrets/staging_secrets.enc.yml
Secrets[:staging].save

# on a subsequent run, this will load the previously saved staging secrets
Secrets.register(:staging) # => returns instance of Secrets for staging
Secrets.register(:shared) # => returns false as we haven't saved shared secrets

Note: each time you save a secrets store, you will get differing file contents even if no secrets have been added, removed, or changed. This is a security feature and the result of us using nonces.

Best Practices

• Do not commit encryption keys (e.g. .production_secret_key) to a repo!
• Do not accidentally bake an encryption key into a public Docker image!
• Do not commit code that directly sets secrets like above, obviously this will add the secrets in plaintext form to your repo!
• Distribute encryption keys to trusted developers if they need to have access to the corresponding secrets
• Use multiple secret stores for different types of secrets i.e. production, development, and shared if you have secrets used by one or more environment
• Integrate this library in some way with your app / dev environment so you have a way to quickly edit encrypted secrets. Right now this is left up to the user, however a later version may provide some sort of CLI for doing this similar to Amber's amber encrypt.
• Provide the necessary encryption keys when running deployments