policy-password is a library to generate passwords
from policies given constraints.

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The purpose of this library is to provide a powerful password generator based on a PasswordPolicy configuration. This especially useful when using a library such as keycloak. Keycloak provides the ability to set password policies per realm which can be obtained and parsed to generate passwords with this library.

Installation

To install this library, run

yarn add policy-password
yarn install

or

npm i policy-password

depending on your package manager.

Usage

This library provides a class and a function based approach to generate passwords and/or policies. Generally, we need to build our policy first which we can then use to generate a password from.

generateCompliantPassword({ policy[, constraints, includeList, excludeList, samplePolicy] })

Generate a single password given the passwordPolicy and the minPolicyConstraints from the GeneratorConfig.

/* Policy dictates that we want a password that is at least six characters long
   with a minimum of two special characters, two digits and two uppercase
   letters.
 */
const policy: Policy = {
  special: 2,
  digit: 2,
  upper: 2,
};
/* Prepare our config that holds the policy for password generation.
 */
const config: GeneratorConfig = { policy, samplePolicy: true };
/* Generate 35 passwords with our predefined policy atop.
 */
const password: Password = generateCompliantPassword(config);

new PasswordGenerator({ policy[, constraints, includeList, excludeList, samplePolicy] }).generate()

/* Policy dictates that we want a password that is at least 12 characters long
   with a minimum of two two digits and two uppercase letters.
 */
const policy: Policy = {
  length: 12,
  digit: 2,
  upper: 2,
};
/* We want to have a constraint of minimum eight lowercase characters but only
   with letters [a-m] and not so fancy special chars.
 */
const config: GeneratorConfig = {
  policy,
  samplePolicy: true,
  includeList: {
    ...defaultIncludeList,
    special: '!?#+-_',
    lower: 'abcdefghijklm',
  },
};
const passwordGenerator = new PasswordGenerator(config);
const password: Password = passwordGenerator.generate();

Configuration options with GeneratorConfig

No matter the method you choose to generate a password, you always have to provide a GeneratorConfig. An overview of the various configuration options is outlined in this table:

Option name	Type	Description	Default value	Required
policy	Policy | DefinitePolicy	The policy that dictates the length and character pool for your generated passwords.	{}	yes
constraints	Constraints	Constraints consist of mandatory minimum and maximum constraints. Constraints can be used to sample a policy when the samplePolicy flag is set to true.	policyNistRecommendations (see constants.ts for more information)	no
includeList	IncludeList	An object that maps the individual quantifiable keys (upper, lower, digit, special) onto valid characters. The include list spans the pool of characters which are used to build the generated password.	defaultIncludeList (see constants.ts for more information)	no
excludeList	ExcludeList	An array of characters to exclude from generated passwords. Takes precedence over the given or default include list.	[]	no
samplePolicy	boolean	A flag to control whether a policy should be sampled from given or default constraints.	false	no

How to run an example

You can run an example, e.g. the function/password.example.ts in the examples folder like so:

yarn run example:func

Development

In case you want to develop on or contribute to this library, make sure to check out the remote HEAD and install all dependencies with your favorite package manager for NodeJs. To run this application type

yarn start

or

npm start

Testing

To run the test suite of this library, type

yarn test

or

npm test

Code style & lint

Please pay attention to the .editorconfig and .eslintrc.js and stick to those rules. PR's in that regard are welcome as well!

Author

Thomas Hesse

License