Rudric

A simple secrets vault.

Rudric makes managing secrets from the command line simple and straight-forward. Secrets are stored encrypted on disk and can be quickly decrypted and added to the environment where needed. Cleartext secrets are only ever stored in memory.

Purpose

I use .env files a lot to store sensitive data like API keys and personal access tokens. While .env files are "hidden" by default on Linux and Mac, this isn't really security. Anyone could grep the filesystem and find all sorts of plaintext secrets. Storing secrets encrypted, and only decrypting them when needed would be a much better solution.

Installation

The following installation methods are currently supported:

• cargo install rudric
• nix install github:mike-lloyd03/rudric (Requires Flakes to be enabled)

Usage

.env files can instead be replaced with .renv files which use bash-like syntax for defining environment variables.

GITHUB_TOKEN={{personal_github_token}}
GITHUB_API=https://api.github.com

This would create an environment variable called GITHUB_TOKEN which is set to the value of a secret in your vault called personal_github_token. Additionally, non-secret values can be stored here as well and they will also be set in the environment.

Multiple secrets can be used in a single environment variable. Additionally, string interpolation is supported.

DATABASE_URL=postgres://{{pg_user}}:{{pg_pass}}@localhost:5432

Using rudric env <shell_name>, these variables can be set in your environment.

fish:

rudric env fish | source

bash:

source <(rudric env bash)

A default shell can be specified by setting it in the configuration file.

Getting Started

Initialization

This first step is to generate a new vault with rudric init. You will be asked to set a master password. Once done, your vault will be created.

Interacting with the vault

Secrets can be created, fetched, edited, and deleted.

rudric create <new_secret_name>

A text editor will be opened (whatever is defined by EDITOR or VISUAL environment variables). Optionally, the user can create a secret from the content of a file with the --file flag. Or, if a session is active, the user can create a secret by piping text from another process:

pwgen -1 14 | rudric create <new_secret_name> -

[!IMPORTANT] A valid session token must be set for reading from a pipe to work correctly. Currently, the Rust crate dialoguer has a bug which prevents input prompts from being displayed correctly when data is piped into the program.

The following other commands are supported:

• edit
• list
• delete (asks for confirmation)
• change-password

Sessions

To avoid having to type your master password every time you interact with the vault, you can create a session token which must be set in the environment as RUDRIC_SESSION. A simple shorthand for this might look like.

set -x RUDRIC_SESSION $(rudric session)

Session tokens are valid for 8 hours by default but this can be configured. The current session token can be revoked with rudric session end.

Encryption

The master password is salted and hashed using the Argon2i algorithm.

Secret values are encrypted before writing to the database using XChaCha20Poly1305.

A higher order key is derived from your master password using a key derivation function based on Argon2i. This key is used for encrypting and decrypting secrets.

Session Tokens

Session token generation is a convenience and obviously makes some security compromises in order to achieve this convenience. However, with proper management of your session tokens, there is a low risk of compromise. Don't ever store your session tokens on the disk. If someone managed to get both your vault database and your session token, all of your secrets could be decrypted.

Session Token Generation

Session tokens are generated using the following method:

• An expiration time is set.
• A random key (the session key) is generated and written to the vault.
• The user's master key is derived from the master password and stored salt.
• The master key is prepended with the expiration time. This is encrypted using the session key.
• The encrypted expiration time and master key are prepended again with the UUID of the session key. This is base64 encoded and returned to the user as the session token.

If the RUDRIC_SESSION token is set in the environment:

• The session key is fetched from the database using the UUID found in the session token
• The expiration time and master key are decrypted from the session token using the session key
• If the token is not expired, the master key will be used to interact with secrets in the vault.

Configuration

Rudric can be configured with a toml file. By default, this file is stored in XDG_CONFIG/rudric/config.toml ($HOME/.config/rudric/config.toml on Linux and Mac). All config options are optional. An example config file might look like this:

# Options are: bash, zsh, fish, nu (default "bash")
default_shell = "fish"

# Specify the default length of time that a session token is valid for (default "8h")
session_lifetime = "6h"

# Specify the name of the file to use in the CWD for setting environment variables (default ".renv")
renv_filename = ".env"

direnv

Rudric includes support for direnv. However, in order to use it, you will have to start a Rudric session before using direnv.

Simply add the following to your .envrc file:

$(rudric env direnv)

Changing into the directory with both a .envrc and .renv file will automatically source your encrypted secrets in the environment.

[!IMPORTANT] FISH USERS: If a valid session token is not set, changing into a directory with a trusted .envrc will prompt you for your password. This will fail and your terminal will hang as input will not be passed to Rudric. This is due to a bug in direnv not being able to read stdin in fish.

As a workaround, you can add stty sane to the top of your .envrc file:

stty sane
$(rudric env direnv)

See:
https://github.com/direnv/direnv/issues/967
https://github.com/direnv/direnv/issues/1237

Crates

Encryption is all accomplished using the fantastic Orion library.

Additional crates in use:

• clap
• sqlx
• dialoguer
• serde
• colored_json
• tabled