EasyRSA

Simple and Secure Wrapper for phpseclib.

Important!

For better security, you want to use libsodium, not EasyRSA.

Motivation

Although the long-term security of RSA is questionable (at best) given the advances in index calculus attacks, there are many issues with how RSA is implemented in popular PHP cryptography libraries that make it vulnerable to attacks today.

Thanks to the folks who developed phpseclib, it's possible to use secure RSA in PHP. However, it's not user-friendly enough for the average PHP developer to use to its full potential. So we took it upon ourselves to offer a user-friendly interface instead.

EasyRSA is MIT licensed and brought to you by the secure PHP development team at Paragon Initiative Enterprises.

How to use this library?

composer require paragonie/easyrsa

Generating RSA key pairs

You can generate 2048-bit keys (or larger) using EasyRSA. The default size is 2048.

use \ParagonIE\EasyRSA\KeyPair;

$keyPair = KeyPair::generateKeyPair(4096);

$secretKey = $keyPair->getPrivateKey();
$publicKey = $keyPair->getPublicKey();

Encrypting/Decrypting a Message

use \ParagonIE\EasyRSA\EasyRSA;

$ciphertext = EasyRSA::encrypt($message, $publicKey);

$plaintext = EasyRSA::decrypt($ciphertext, $secretKey);

Signing/Verifying a Message

use \ParagonIE\EasyRSA\EasyRSA;

$signature = EasyRSA::sign($message, $secretKey);

if (EasyRSA::verify($message, $signature, $publicKey)) {
    // Signature is valid!
}

What Does it Do Under the Hood?

• Encryption (KEM+DEM)
  • Generates an random secret value
  • Encrypts the random secret value with your RSA public key, using PHPSecLib (RSAES-OAEP + MGF1-SHA256)
  • Derives an encryption key from the secret value and its RSA-encrypted ciphertext, using HMAC-SHA256.
  • Encrypts your plaintext message using defuse/php-encryption (authenticated symmetric-key encryption)
  • Calculates a checksum of both encrypted values (and a version tag)
• Authentication
  • Signs a message using PHPSecLib (RSASS-PSS + MGF1-SHA256)