PHP Extension Requires Chilkat v11.0.0+

RSA Encrypt and Decrypt Strings

See more RSA Examples

_LANGUAGE_ sample code to RSA public-key encrypt and decrypt strings using public and private keys. PHP Extension

<?php

include("chilkat.php");

$success = false;

//  This example assumes the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

$rsa = new CkRsa();

//  This example also generates the public and private
//  keys to be used in the RSA encryption.
//  Normally, you would generate a key pair once,
//  and distribute the public key to your partner.
//  Anything encrypted with the public key can be
//  decrypted with the private key.  The reverse is 
//  also true: anything encrypted using the private
//  key can be decrypted using the public key.

//  Generate a 2048-bit key.  Chilkat RSA supports
//  key sizes ranging from 512 bits to 4096 bits.
$privKey = new CkPrivateKey();
$success = $rsa->GenKey(2048,$privKey);
if ($success == false) {
    print $rsa->lastErrorText() . "\n";
    exit;
}

$pubKey = new CkPublicKey();
$privKey->ToPublicKey($pubKey);

$plainText = 'Encrypting and decrypting should be easy!';

//  Start with a new RSA object to demonstrate that all we
//  need are the keys previously exported:
$rsaEncryptor = new CkRsa();

//  Encrypted output is always binary.  In this case, we want
//  to encode the encrypted bytes in a printable string.
//  Our choices are "hex", "base64", "url", "quoted-printable".
$rsaEncryptor->put_EncodingMode('hex');

//  We'll encrypt with the public key and decrypt with the private
//  key.
$success = $rsaEncryptor->UsePublicKey($pubKey);

$usePrivateKey = false;
$encryptedStr = $rsaEncryptor->encryptStringENC($plainText,$usePrivateKey);
print $encryptedStr . "\n";

//  Now decrypt:
$rsaDecryptor = new CkRsa();

$rsaDecryptor->put_EncodingMode('hex');
$success = $rsaDecryptor->UsePrivateKey($privKey);

$usePrivateKey = true;
$decryptedStr = $rsaDecryptor->decryptStringENC($encryptedStr,$usePrivateKey);

print $decryptedStr . "\n";

?>