convict-secret-format

Description

Adds a new validation format for secrets to prevent secrets from being logged in stdout.

Motivations

node-convict currently exposes a property to flag secrets as sensitive by stating sensitive: true during initialization. However, this only redacts sensitive information if you were to coerce the convict object to a string. Logging the the object from the return value of convict().getProperties() will output sensitive information.

This package serves to expose a new format to always mask secret values.

Example of secret logging leaks

The code snippet below exemplifies how a secret can get logged by accident even when its been marked as sensitive.

const config = convict({
  secret: {
    env: "SECRET",
    default: "secret-key-value",
    sensitive: true,
  },
});

// This line will include `secret-key-value` in logs
console.log(config.getProperties());

// Only when you coerce config to string, will the value be changed to SENSITIVE
console.log(config.toString());

Usage

Simply extend convict with the new format by calling getSecretConfigFormat(). Then, state the default format name, secret-format as the format to use in your configs.

Note: The values in your .env file will automatically get coerced to the SecretConfig type.

# extend convict format with SecretConfig
convict.addFormat(getSecretConfigFormat());

# use the `secret-format` format. With the config below, the value of `SECRET` in your `.env` file will be coerced to `SecretConfig`
const config = convict({
  secret: {
    env: 'SECRET',
    default: SecretConfig(""),
    format: "secret-format",
  }
})

// All secrets will output REDACTED
console.log(config.getProperties())

// If you wish to get the value of the secret, call `getValue()`
console.log(config.getProperties().secret.getValue())

Validation

This will not work as the default value does not conform to the SecretConfigProps type

const config = convict({
  secret: {
    env: "SECRET",
    default: { value: "test" },
    format: "secret-format",
  },
});

// throws a TypeError since value does not conform to shape of `SecretConfigProps`
config.validate();

Formatting options available

getSecretConfigFormat exposes options to customize the following:

1. censorFn: A callback function to change the toString or toJSON representation of the secret value.
2. formatName: The name of the format to pass to format property. Use this in event of format naming collisions with the default secret-format name.

Example

convict.addFormat(
  getSecretConfigFormat({
    censorFn: () => "censored",
    formatName: "secret-format-2",
  })
);

// now you have to use secret-format-2 as the name in format instead
const config = convict({
  secret: {
    env: "SECRET",
    default: SecretConfig(""),
    format: "secret-format-2",
  },
})
  .validate()
  .getProperties();

// this will now output `censored`, instead of `REDACTED`
console.log(config.secret);