Comeonin

Password hashing (bcrypt, pbkdf2_sha512) library for Elixir.

This library is intended to make it very straightforward for developers to check users' passwords in as secure a manner as possible.

Comeonin supports bcrypt and pbkdf2_sha512.

Features

Comeonin uses the most secure, up-to-date hashing schemes.
It uses the latest version of bcrypt, supporting the $2b$ prefix.
It is easy to use.
- There are several convenience functions to make checking passwords easier.
- Salts are generated by default.
- Each function has sensible, secure defaults.
It provides excellent documentation.
- Clear instructions are given on how to use Comeonin.
- Several recommendations are also given to help developers keep their apps secure.

Requirements and build errors

See the Requirements page in the wiki for details.

Installation

Add comeonin to your mix.exs dependencies

defp deps do
  [ {:comeonin, "~> 1.4"} ]
end

List :comeonin as an application dependency

def application do
  [applications: [:logger, :comeonin]]
end

Run mix do deps.get, compile
Optional: during tests (and tests only), you may want to reduce the number of bcrypt, or pbkdf2, rounds so it does not slow down your test suite. If you have a config/test.exs, you should add (depending on which algorithm you are using):
```
 config :comeonin, :bcrypt_log_rounds, 4
 config :comeonin, :pbkdf2_rounds, 1
```

NB: do not use the above values in production.

Usage

Either import or alias the algorithm you want to use -- either Comeonin.Bcrypt or Comeonin.Pbkdf2.

Both algorithms use similar naming conventions so as to make it easy to switch between them. Both have the hashpwsalt function, which is a convenience function that automatically generates a salt and then hashes the password.

To hash a password with the default options:

hash = hashpwsalt("difficult2guess")

See each module's documentation for more information about all the available options.

To check a password against the stored hash, use the checkpw function. This takes two arguments: the plaintext password and the stored hash:

checkpw(password, stored_hash)

There is also a dummy_checkpw function, which takes no arguments and is to be used when the username cannot be found. It performs a hash, but then returns false. This can be used to make user enumeration more difficult.

Generating passwords and checking password strength

In the Comeonin.Password module, there are functions to generate random passwords and to check passwords for password strength.

There is also a create_hash function in the main Comeonin module which can be used to check a password for password strength before hashing it.

The password strength check consists of three options: a minimum length, a check for punctuation characters and digits and a common password check.

Interacting with a database

The create_user function in the Comeonin module takes a map, removes the "password" entry, checks the password for password strength (see the section above for details), and then hashes the password and adds a "password_hash" entry to the map. If there are no errors, it returns the new map.

Documentation

http://hexdocs.pm/comeonin

License

BSD. For full details, please read the LICENSE file.

andyduong1920/comeonin