PHP Extension

Generate RSA Key and Sign a String

See more RSA Examples

Demonstrates how to generate a new RSA public/private key pair and use it to generate a signature for a string. The (binary) digital signature is returned as a hexidecimalized string. 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();

// Generate a 2048-bit RSA key.
$privKey = new CkPrivateKey();
$success = $rsa->GenKey(2048,$privKey);

$rsa->UsePrivateKey($privKey);

// Return the signature in hex.
$rsa->put_EncodingMode('hex');

$strData = 'This is the string to be signed.';

// Sign the SHA256 hash of the string.
$hexSig = $rsa->signStringENC($strData,'sha256');

print $hexSig . "\n";

// Now verify the signature:
$pubKey = new CkPublicKey();
$privKey->ToPublicKey($pubKey);
$rsa->UsePublicKey($pubKey);

$success = $rsa->VerifyStringENC($strData,'sha256',$hexSig);
if ($success == true) {
    print 'Signature verified!' . "\n";
}
else {
    print $rsa->lastErrorText() . "\n";
}

// Try it with an invalid signature:
$success = $rsa->VerifyStringENC($strData,'sha256','not a valid sig');
if ($success == true) {
    print 'Signature verified!' . "\n";
}
else {
    print 'Signature validation failed!' . "\n";
}

// Try it with invalid data:
$success = $rsa->VerifyStringENC('Not the original data','sha256',$hexSig);
if ($success == true) {
    print 'Signature verified!' . "\n";
}
else {
    print 'Signature validation failed!' . "\n";
}


?>