Generating Public & Private Keys Using PHPSECLIB

A few tasks that I’ve been working on this weekend have needed public/private key pairs. The very useful phpseclib library provides the tools that you need to generate these within your application.

// Get a new RSA object and set the type, hash and comment
$rsa = new RSA;
$rsa->setPublicKeyFormat(phpseclib\Crypt\RSA::PUBLIC_FORMAT_OPENSSH);
$rsa->setHash('sha256');
$rsa->setComment('user@seccheck');
// Actually generate the key, change 4096 for the desired number of bytes

$keys 		= $rsa->createKey(4096);

$keyPrivate	= $keys[“privatekey”];

$keyPublic	= $keys[“publickey”];
// Get the fingerprint for this key

$rsa->loadKey($keyPrivate);

$keyFingerprint = $rsa->getPublicKeyFingerprint();