PHP ActiveX

RSA Signature using Private Key from .snk File

See more RSA Examples

A .snk file (Strong Name Key file) is a file format used in the .NET ecosystem to store an RSA public/private key pair. This key pair is typically used for strong-naming assemblies, which is a process of signing .NET assemblies to ensure their integrity and to uniquely identify them.

This example loads a private key from a .snk file and creates an RSA signature.

PHP ActiveX

<?php

$success = 0;

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

// Load the .snk and return the private key as XML.
$xmlStr = $rsa->snkToXml('./test.snk');
if ($rsa->LastMethodSuccess == 0) {
    print $rsa->LastErrorText . "\n";
    exit;
}

$privKey = new COM("Chilkat.PrivateKey");
$success = $privKey->LoadXml($xmlStr);
if ($success == 0) {
    print $privKey->LastErrorText . "\n";
    exit;
}

$success = $rsa->UsePrivateKey($privKey);
if ($success == 0) {
    print $rsa->LastErrorText . "\n";
    exit;
}

// Sign the SHA-256 hash of the utf-8 byte representation of the contents of sb
// Return the signature in base64 format.
$rsa->EncodingMode = 'base64';
$rsa->Charset = 'utf-8';
$sigBase64 = $rsa->signStringENC('This is the text to be hashed and signed.','sha256');
if ($rsa->LastMethodSuccess == 0) {
    print $rsa->LastErrorText . "\n";
    exit;
}

print 'RSA signature as base64: ' . $sigBase64 . "\n";

?>