PHP

RSA Sign an Encoded Hash

See more RSA Examples

Demonstrates signing a hash (e.g., SHA256) provided as an encoded string (e.g., base64 or hex). Chilkat2 PHP

<?php

use Chilkat2\BinData;
use Chilkat2\Cert;
use Chilkat2\Rsa;

$success = false;

// 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 the private key for this cert: ', $cert->SubjectCN, "\n";

// Create data to be hashed and signed.
$bd = new BinData();
for ($i = 0; $i <= 100; $i++) {
    $bd->AppendEncoded('000102030405060708090A0B0C0D0E0F', 'hex');
}

$rsa = new Rsa();

// Use the certificate's private key for signing.
try {
    $rsa->SetX509Cert($cert, true);
    $success = true;
} catch (\Chilkat2\Exception $e) {
    $success = false;
}
if (!$success) {
    echo $rsa->LastErrorText, "\n";
    exit;
}

// We'll first compute the hash and then pass the encoded hash to be signed.
$sha256_base64 = $bd->GetHash('sha256', 'base64');
echo 'sha256 hash in base64 format: ', $sha256_base64, "\n";

// Pass in the base64 hash and return a base64 signature.
$rsa->EncodingMode = 'base64';
$rsaSig_base64 = $rsa->SignHashENC($sha256_base64, 'sha256');
if (!$success) {
    echo $rsa->LastErrorText, "\n";
    exit;
}

echo 'RSA signature as base64: ', $rsaSig_base64, "\n";