(PHP ActiveX) RSA Sign utf-8 Bytes of String to get Base64 RSA Signature

See more Apple Keychain Examples

Demonstrates how RSA sign the utf-8 byte representation of a string to get the signature in base64 format.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows Note: The php_com_dotnet.dll may need to be enabled inside of php.ini.

<?php

// Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
// this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

// Chilkat automatically detects and determines the way in which the HSM is used,
// which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Cert')
$cert = new COM("Chilkat.Cert");

// Set the token/smartcard PIN prior to loading.
$cert->SmartCardPin = '123456';

// Specify the certificate by its common name.
$success = $cert->LoadFromSmartcard('cn=chilkat-rsa-2048');
if ($success == 0) {
    print $cert->LastErrorText . "\n";
    exit;
}

print 'Signing with cert: ' . $cert->SubjectCN . "\n";

// Create a string to be hashed and signed.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.StringBuilder')
$sb = new COM("Chilkat.StringBuilder");
$crlfLineEnding = 1;

for ($i = 0; $i <= 10; $i++) {
    $sb->AppendLine('This is a test.',$crlfLineEnding);
}

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Rsa')
$rsa = new COM("Chilkat.Rsa");

// Use the certificate's private key for signing.
$success = $rsa->SetX509Cert($cert,1);
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';
$stringToSign = $sb->getAsString();
$sigBase64 = $rsa->signStringENC($stringToSign,'sha256');
if ($rsa->LastMethodSuccess == 0) {
    print $rsa->LastErrorText . "\n";
    exit;
}

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

?>