README

Various encryption helpers, uses paragonie/halite (which uses Sodium) for cryptography. Support key rotation.

Usage in Nette framework

Although it can be used anywhere, this library doesn't depend on anything from the Nette Framework.

Define encryption keys

Add this (or similar) to your config.local.neon parameters section (DO NOT COMMIT THIS TO REPOSITORY):

encryption:
    keys:
        passwordHash:
            prod1: "phek_abadcafec15c..." # prefix _ [0-9A-F]{64}
        email:
            prod1: "eek_cafebabe25da..." # prefix _ [0-9A-F]{64}
    activeKeyIds:
        passwordHash: prod1
        email: prod1
    prefixes:
        passwordHash: phek # password hash encryption key
        email: eek # email encryption key

YOU HAVE TO GENERATE YOUR OWN KEYS. You can use for example

bin2hex(random_bytes(32))

to generate a key, then add the prefix. You can have multiple keys in each group (here we see two groups: password and email), meaning you will be able to decrypt data encrypted with these keys. Data will always be encrypted with what's defined in activeKeyIds section.

The configuration is an example one, you don't need to use groups, or even the config key names (like activeKeyIds), the only place where these will be used is when you define the service, or services.

Services

Then define services for each key group (feel free to commit this):

services:
    emailEncryption: \Spaze\Encryption\SymmetricKeyEncryption(%encryption.keys.passwordHash%, %encryption.activeKeyIds.passwordHash%, %encryption.prefixes.passwordHash%)
    passwordHashEncryption: \Spaze\Encryption\SymmetricKeyEncryption(%encryption.keys.email%, %encryption.activeKeyIds.email%, %encryption.prefixes.email%)

Use the services in this class which needs to encrypt and decrypt email addresses for whatever reason:

use Spaze\Encryption\SymmetricKeyEncryption;

class Something
{

    public function __construct(
        private SymmetricKeyEncryption $emailEncryption,
    ) {
        // ...
    }

    public function doSomething()
    {
        // ...
        $encryptedEmail = $this->emailEncryption->encrypt($email);
        // ...
    }


    public function doSomethingElse()
    {
        // ...
        $decryptedEmail = $this->emailEncryption->decrypt($email);
        // ...
    }

}

Pass the properly configured encryption service to the class:

services:
    something: Something(emailEncryption: @emailEncryption)

Key rotation

You can always add a new encryption key, set it as an active key and from that moment, the data will be encrypted with the new key. Unless you remove the old key, it will be possible to decrypt data encrypted with it. You can then take all the data encrypted with the old key and re-encrypt them just to change they key which was used to encrypt them. Once done you can delete the old key.

You can use needsReEncrypt($ciphertext): bool to see if the data is encrypted with an inactive key and thus should be re-encrypted with the currently active one.

Running tests

If you want to contribute (awesome, thanks!), you should add/run tests for your contributions. First install dev dependencies by running composer install, then run tests with composer test, see scripts in composer.json. Tests are also run on GitHub with Actions on each push.

You can fix coding style issues automatically by running composer cs-fix.

spaze / encryption

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