PHP

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. Chilkat2 PHP

<?php

use Chilkat2\Cert;
use Chilkat2\Rsa;
use Chilkat2\StringBuilder;

// 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 Cert();

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

// Specify the certificate by its common name.
try {
    $cert->LoadFromSmartcard('cn=chilkat-rsa-2048');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo 'Signing with cert: ', $cert->SubjectCN, "\n";

// Create a string to be hashed and signed.
$sb = new StringBuilder();
$crlfLineEnding = true;
for ($i = 0; $i <= 10; $i++) {
    $sb->AppendLine('This is a test.', $crlfLineEnding);
}

$rsa = new Rsa();

// Use the certificate's private key for signing.
try {
    $rsa->SetX509Cert($cert, true);

    // 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');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo 'RSA signature as base64: ', $sigBase64, "\n";