Question

Ok so i am VERY new to cryptography

I want to encrypt a string using RSA. i have found many examples but most of them generate their own public/private keys or they use some other key format like pem/crt etc

I have my own public and private key file in the format of .key

Public key -> http://pastebin.com/hPT9LRCT 
Private key-> http://pastebin.com/UYgJp8K7

How do i encrypt a string (“hello world”) using my public key in php?

Could you show me an example or point me in the right direction?

thanks,
Vidhu

Answer 1

Try this (uses phpseclib, a pure PHP RSA implementation):

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

$rsa = new Crypt_RSA();
$rsa->loadKey('MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEArd+uKDi7g6cpmbotPre9KpFK4U1rM/FlEtHszIrMBmArLID4/uImes2L6K5sbKHbo3sIVdzFgrtB/ZdHTN11bM26OLpovCMs/HF3tqz93RMobdNv63IyOau4YgKZa+U2sW+1fGT1HtBesqGjlVlLZNJVR9ZETj4fuLKjNzOgegdbYFV9jIyP6JDi/9c6oyFRUI1anSWZcDFL+74Y4h4okAcbDgooczxBf3QlIJQdFVs9GOPCoIwmZ29c4VmBvESlRnjtXho/6sNQXlnLsG4v4GCzL7P1YOOf9FqV8XZuXJrEsTVJjDdYJdia6F3G/GRe+lRhReM42qlHqLKZpzjSFwIDAQAB'); // public key

$plaintext = 'hello world';

$rsa->setEncryptionMode(CRYPT_RSA_ENCRYPTION_PKCS1);
$ciphertext = $rsa->encrypt($plaintext);