Oirė Colloportus

Wraps Bcrypt-SHA384 in Authenticated Encryption. A simplified fork of Password Lock by Paragon Initiative Enterprises. Integrates parts of Defuse PHP Encryption for authenticated symmetric-key encryption. Depends on Oirė Base64 for encoding binary data to a storable format.

About the Name

Colloportus is a magical spell in the well-known Harry Potter series. It locks doors in a very hard-to-open way, and such a door is completely impossible to open for muggles, i.e., non-wizarding people. I decided to use this as a name for my simplified fork of PasswordLock. The method names are also simplified: lock, check and flip instead of HashAndEncrypt, DecryptAndVerify and RotateKey.

Requirements

Requires PHP 7.1.2 or later with mbString and openSSL enabled.

Installation

Via Composer:

composer require oire/colloportus

Or manually. Note that you will need base64.php from Oirė Base64:

require_once("oire/base64.php");
require_once("oire/colloportus.php");

Running Tests

Run ./vendor/bin/phpunit in the projects directory.

Usage Examples

Hash Password, Encrypt Hash, Authenticate Cipher Text

use \Oire\Colloportus;
try {
	$key = Colloportus::createKey();
	// To save the key in a storable form, either pass false as parameter to the createKey() method, or do:
	$storable = Colloportus::save($key);
} catch(Exception $e) {
	// Handle errors
}
if (isset($_POST['password'])) {
	try {
		// You may lock the password with a storable key. To do this, pass false as the third parameter
		$storeMe = Colloportus::lock($_POST['password'], $key);
	} catch(Exception $e) {
		// Handle errors
	}
}

Verify MAC, Decrypt Ciphertext, Verify Password

if (isset($_POST['password'])) {
	try {
		// You may verify the password with a storable key. To do this, pass false as the fourth parameter
		$verified = Colloportus::check($_POST['password'], $storeMe, $key);
	} catch(Exception $e) {
		// Handle errors
	}
	if ($verified) {
		// Success!
	}
}

Re-encrypt a hash with a different encryption key

try {
	$newKey = Colloportus::createKey();
} catch(Exception $e) {
	// Handle errors
}
try {
	$newHash = Colloportus::flip($storeMe, $key, $newKey);
} catch(Exception $e) {
	// Handle errors
}

Methods

All Colloportus methods are public and static, so no class instance is required. The methods are documented in the source file, but their description is given below. We recommend to wrap every call in try...catch since Colloportus throws exceptions in case of errors.

• public static function createKey(bool $rawBinary = true): string ? Creates a random encryption key. If the parameter is set to true, a raw binary key will be returned. If it is set to false, the key will be returned in a storable (i.e., readable) form.
• public static function encrypt(string $plainText, string $key, bool $rawKey = true, bool $rawBinary = false): string ? Encrypts given string data with a given key. If $rawKey is set to true, it is assumed that the key is passed as raw binary data, a storable key is assumed otherwise. If $rawBinary is set to true, the encrypted data are returned as binary string, a storable string is returned otherwise.
• public static function decrypt(string $cipherText, string $key, bool $rawKey = true, bool $rawBinary = false): string ? Decrypts given cipher text with a given key. If $rawKey is set to true, it is assumed that the key is passed as raw binary data, a storable key is assumed otherwise. If $rawBinary is set to true, it is assumed that the cipher text is passed as raw binary data, a storable string is accepted otherwise.
• public static function lock(string $password, string $key, bool $rawKey = true): string ? Locks given password with given key. If $rawKey is set to true, it is assumed that the key is passed as raw binary data, a storable key is accepted otherwise. Returns a storable string.
• public static function check(string $password, string $cipherText, string $key, bool $rawKey = true): bool ? Verifies the given password against given storable cipher text. If $rawKey is set to true, it is assumed that the key is passed as binary data, a storable string is accepted otherwise. Returns true on success or false on failure.
• public static function flip(string $cipherText, string $oldKey, string $newKey, bool $rawOldKey = true, bool $rawNewKey = true, bool $rawBinaryOld = false, bool $rawBinaryNew = false): string ? Allows to re-encrypt the password hash with a different key (for example, if the old key is compromised and the hashes are not). If $rawOldKey and/or $rawNewKey are set to true, it is assumed that the old and/or new keys are in raw binary form, storable strings are accepted otherwise. If $rawBinaryOld and/or $rawBinaryNew are set to true, it is assumed that the old cipher text is in raw binary form and/or the new cipher text will be returned in raw binary form.
• public static function save(string $binary): string ? Allows to save a raw binary string (for example, the newly created key) as a storable string.
• public static function load(string $storable): string ? Allows to transform a storable string in raw binary data.

Differences between Password Lock and Colloportus

• All methods needed for encryption/decryption are provided along with the hashing/verifying methods.
• Back-porting to older PHP versions is removed, hence PHP 7.1.2 is required (the hash_hkdf() method was added in this particular version).
• Custom string processing implementations are removed, mbstring is required.
• Version header check is removed.
• encrypt() and, subsequently, Lock() returns URL/filename-safe Base64 data instead of hexits.
• All sha256 instances are changed to sha384.
• Code style changed to match Oirė standards.

Contributing

All contributions are welcome. Please fork, make a feature branch, hack on the code, run tests, push your branch and send a pull-request.

License

Copyright © 2017-2019, Andre Polykanine. This software is licensed under an MIT license.