<?php
include ('Crypt/RSA.php');

$rsa = new Crypt_RSA ();
$rsa->setEncryptionMode(CRYPT_RSA_ENCRYPTION_PKCS1);
$rsa->setPrivateKeyFormat(CRYPT_RSA_PRIVATE_FORMAT_PKCS1);
$rsa->setPublicKeyFormat(CRYPT_RSA_PUBLIC_FORMAT_PKCS1);

$encryptedToken = "";
$privateKeyFile = "path/to/my/private.key";

/*
 * Decrypt
 * Load the private encryption key from a file and decrypt the plaintext.
 */
$rsa->loadKey(file_get_contents($privateKeyFile)) or die ("Can't load key.");
// private key
$plain = $rsa->decrypt(base64_decode($ciphertext));

echo $plain;
echo "\n";
?>