Password Generator for HashiCorp Vault

The Vault Password Generator is a Vault secrets plugin for generating cryptographically secure passwords and passphrases.

This is both a real custom Vault secrets plugin, and an example of how to build, install, and maintain your own Vault secrets plugin.

Setup

The setup guide assumes some familiarity with Vault and Vault's plugin ecosystem. You must have a Vault server already running, unsealed, and authenticated.

1. Download and decompress the latest plugin binary from the Releases tab on GitHub. Alternatively you can compile the plugin from source, if you're into that kinda thing.

2. Move the compiled plugin into Vault's configured plugin_directory. You must set this value in the server configuration:

   $ mv vault-secrets-gen /etc/vault/plugins/vault-secrets-gen

3. Enable mlock so the plugin can safely be enabled and disabled:

   setcap cap_ipc_lock=+ep /etc/vault/plugins/vault-secrets-gen

4. Calculate the SHA256 of the plugin and register it in Vault's plugin catalog. If you are downloading the pre-compiled binary, it is highly recommended that you use the published checksums to verify integrity.

   $ export SHA256=$(shasum -a 256 "/etc/vault/plugins/vault-secrets-gen" | cut -d' ' -f1)
   
   $ vault plugin register \
       -sha256="${SHA256}" \
       -command="vault-secrets-gen" \
       secret secrets-gen

5. Mount the secrets engine:

   $ vault secrets enable \
       -path="gen" \
       -plugin-name="secrets-gen" \
       plugin

Upgrade plugin

In order to upgrade, you can repeat the decompress, move and register steps with the new version:

```sh
$ export SHA256=$(shasum -a 256 "/etc/vault/plugins/vault-secrets-gen_vX.X.X" | cut -d' ' -f1)
$ mv vault-secrets-gen_vX.X.X <vault-plugin-directory>/
$ vault plugin register \
    -sha256="${SHA256}" \
    -command="vault-secrets-gen_vX.X.X" \
    -version="vX.X.X" \
    secret secrets-gen
$ vault secrets tune -plugin-version=v1.0.8 secrets-gen
$ vault plugin reload -plugin secrets-gen
```

Where vX.X.X deontes the target version, you wish to upgrade to. Note that the -version option is only supported in vault server versions staring from 1.12.0, omit it for earlier versions.

See:

• https://developer.hashicorp.com/vault/docs/upgrading/plugins
• https://developer.hashicorp.com/vault/docs/v1.11.x/upgrading/plugins (for vault server versions <1.12.0)

Usage & API

Policy requirements

The token used should have the following policy permissions to be able to generate passwords.

path "gen/password" {
  capabilities = ["create", "update"]
}

Generate Password

Generates a random, high-entropy password with the specified number of characters, digits, symbols, and configurables.

Method	Path	Produces
POST	/gen/password	200 (application/json)

Parameters

• length (int: 64) - Specifies the total length of the password including all letters, digits, and symbols.

• digits (int: 10) - Specifies the number of digits to include in the password.

• symbols (int: 10) - Specifies the number of symbols to include in the password.

• allow_uppercase (bool: true) - Specifies whether to allow uppercase and lowercase letters in the password.

• allow_repeat (bool: true) - Specifies to allow duplicate characters in the password. If set to false, be conscious of password length as values cannot be re-used.

CLI

$ vault write gen/password length=36 symbols=0
Key  	Value
---  	-----
value	27f3L5zKCZS8DD6D2PEK1xm0ECNaImg1PJqg

Generate Passphrase

Generates a random, high-entropy passphrase with the specified number of words and separator using the diceware algorithm.

Method	Path	Produces
POST	/gen/passphrase	200 (application/json)

Parameters

• words (int: 6) - Specifies the total number of words to generate.

• separator (string: "-") - Specifies the string value to use as a separator between words.

CLI

$ vault write gen/passphrase words=4
Key  	Value
---  	-----
value	obstacle-sacrament-sizable-variably

License

This code is licensed under the MIT license.