Sample code for 30+ languages & platforms
PHP ActiveX

RSA Sign with PKCS8 Encrypted Key

See more RSA Examples

Demonstrates how to load a private key from an encrypted PKCS8 file and create an RSA digital signature.

Chilkat PHP ActiveX Downloads

PHP ActiveX
<?php

$success = 0;

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

$pkey = new COM("Chilkat.PrivateKey");

// Load the private key from an RSA PEM file:
$success = $pkey->LoadPkcs8EncryptedFile('privateKey.key','myPassword');

$rsa = new COM("Chilkat.Rsa");

// Import the private key into the RSA object:
$success = $rsa->UsePrivateKey($pkey);
if ($success == 0) {
    print $rsa->LastErrorText . "\n";
    exit;
}

// Return the signature in hex
$rsa->EncodingMode = 'hex';

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

// Sign the string using the sha-1 hash algorithm.
// Other valid choices are "md2", "sha256", "sha384", "sha512",  and "md5".
$hexSig = $rsa->signStringENC($strData,'sha-1');

print $hexSig . "\n";

?>