Hashy

Hash passwords the right way (Argon2 & bcrypt support)

Hashy is small Node.js library which aims to do passwords hashing the correct way.

It has been heavily inspired by the new PHP password hashing API but, following the Node.js philosophy, hashing is done asynchronously.

Furthermore, to make the interfaces as easy to use as possible, async functions can either be used with callbacks or they return promises which will make them super easy to work with async functions!

Supported algorithms:

• Argon2
• bcrypt

Why a new library?

The other ones I found were too complicated and/or were missing important features.

The main missing feature is the needsRehash() function: cryptography is a fast-moving science and algorithms can quickly become obsolete or their parameters needs to be adjusted to compensate the performance increase of recent computers (e.g. bcrypt cost factor).

This is exactly what this function is for: checking whether a hash uses the correct algorithm (and options) to see if we need to compute a new hash for this password.

Install

Installation of the npm package:

> npm install --save hashy

Command line

Hashy also comes with a hashy executable, install it globally to use it from anywhere:

> npm install --global hashy

Hashing a password:

> hashy [ -a <algorithm> ] <secret>

Verifying a password against a hash:

> hashy <secret> <hash>

Use -c/--cost to change the cost when hashing or verifying with Bcrypt, and hashy --help for the full list of options.

How to use it?

First, you may take a look at examples: using callbacks, promises or async functions.

Creating a hash

hashy.hash(password, function (error, hash) {
  if (error) {
    return console.error(error);
  }

  console.log("generated hash: ", hash);
});

hash() handles additionally two parameters which may be passed before the callback:

1. algo: which algorithm to use, it defaults to "argon2";
2. options: additional options for the current algorithm, for bcrypt it defaults to { cost: 10 }, for argon2 to whatever the argon2 package itself defaults to.

Note

Bcrypt silently truncates passwords over 72 bytes, which means two different passwords sharing the same 72-byte prefix would hash (and verify) identically. To avoid this pitfall, hash() and verify() reject with an error rather than truncate silently. If you need to support longer passwords, use argon2 (the default) instead.

Checking a password against a hash

hashy.verify(password, hash, function (error, success) {
  if (error) {
    return console.error(error);
  }

  if (success) {
    console.log("you are now authenticated!");
  } else {
    console.warn("invalid password!");
  }
});

Getting information about a hash

const info = hashy.getInfo(hash);

Checking whether a hash is up to date

As I said earlier, we must be able to check whether the hash is up to date, i.e. if it has been generated by the last algorithm available with the last set of options.

if (hashy.needsRehash(hash)) {
  // Rehash.
}

It handles the optional algo and options parameters like hash().

Changing default options

The default options for a given algorithm is available at hashy.options[<algo>].

// Sets the default cost for bcrypt to 12.
hashy.options.bcrypt.cost = 12;

Using promises

Same interface as above but without the callbacks!

// Hashing.
hashy.hash(password).then(function (hash) {
  console.log("generated hash:", hash);
});

// Checking.
hashy.verify(password, hash).then(function (success) {
  if (success) {
    console.log("you are now authenticated!");
  } else {
    console.warn("invalid password!");
  }
});

As you can see, you don't even have to handle errors if you don't want to!

Using async functions

Same interface as promises but much more similar to a synchronous code!

// Hashing.
(async function () {
  const hash = await hashy.hash(password);
  console.log("generated hash:", hash);
})();

// Checking.
(async function () {
  if (await hashy.verify(password, hash)) {
    console.log("you are now authenticated!");
  } else {
    console.warn("invalid password!");
  }
})();

Contributing

Contributions are very welcome, either on the documentation or on the code.

You may:

• report any issue you've encountered;
• fork and create a pull request.

License

Hashy is released under the MIT license.