(PHP Extension) RSA Hash Binary Data and Sign (and Verify)

Demonstrates how to sign the hash of binary data. Also demonstrates how to verify the RSA signature.

Note: This example uses methods introduced in Chilkat v9.5.0.77.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Load an RSA private key for signing.
$privKey = new CkPrivateKey();
$success = $privKey->LoadEncryptedPemFile('qa_data/pem/rsa_passwd.pem','passwd');
if ($success != true) {
    print $privKey->lastErrorText() . "\n";
    exit;
}

$rsa = new CkRsa();
$rsa->ImportPrivateKeyObj($privKey);

// We have some binary data (in hex) to sign
$originalData = '0102030405060708090A';
$bdData = new CkBinData();
$bdData->AppendEncoded($originalData,'hex');

// Hash (SHA-256) and sign the hash:
$bdSignature = new CkBinData();
$success = $rsa->SignBd($bdData,'sha256',$bdSignature);
if ($success != true) {
    print $rsa->lastErrorText() . "\n";
    exit;
}

// Show the RSA signature in base64
print $bdSignature->getEncoded('base64') . "\n";

// ------------------------------------------
// Get the public key from the private key
// pubKey is a CkPublicKey
$pubKey = $privKey->GetPublicKey();

// Verify the signature..
$rsa2 = new CkRsa();
$rsa2->ImportPublicKeyObj($pubKey);

$bVerified = $rsa2->VerifyBd($bdData,'sha256',$bdSignature);
print 'signature verified: ' . $bVerified . "\n";


?>