(PHP Extension) 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 PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

include("chilkat.php");
// Use "chilkat_9_5_0.php" for versions of Chilkat < 10.0.0

// 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.

$cert = new CkCert();

// Set the token/smartcard PIN prior to loading.
$cert->put_SmartCardPin('123456');

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

print 'Signing with cert: ' . $cert->subjectCN() . "\n";

// Create a string to be hashed and signed.
$sb = new CkStringBuilder();
$crlfLineEnding = true;

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

$rsa = new CkRsa();

// Use the certificate's private key for signing.
$success = $rsa->SetX509Cert($cert,true);
if ($success == false) {
    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->put_EncodingMode('base64');
$rsa->put_Charset('utf-8');
$stringToSign = $sb->getAsString();
$sigBase64 = $rsa->signStringENC($stringToSign,'sha256');
if ($rsa->get_LastMethodSuccess() == false) {
    print $rsa->lastErrorText() . "\n";
    exit;
}

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

?>