(PHP ActiveX) RSA Sign Binary Data and Verify (Recover the Original Data)

Demonstrates how to RSA sign binary data and then verify/recover the original data.

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

Note: This example requires Chilkat v11.0.0 or greater.

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

$success = 0;

// 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 COM("Chilkat.PrivateKey");
$success = $privKey->LoadEncryptedPemFile('qa_data/pem/rsa_passwd.pem','passwd');
if ($success == 0) {
    print $privKey->LastErrorText . "\n";
    exit;
}

$rsa = new COM("Chilkat.Rsa");
$rsa->UsePrivateKey($privKey);

// We have some binary data (in hex) to sign
$originalData = '0102030405060708090A';
$bd = new COM("Chilkat.BinData");
$bd->AppendEncoded($originalData,'hex');

// If successful, the contents of bd are replaced with the RSA signature.
$success = $rsa->SignRawBd($bd);
if ($success == 0) {
    print $rsa->LastErrorText . "\n";
    exit;
}

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

// ------------------------------------------
// Get the public key from the private key
$pubKey = new COM("Chilkat.PublicKey");
$privKey->ToPublicKey($pubKey);

// Verify the signature and extract the original data.
$rsa2 = new COM("Chilkat.Rsa");
$rsa2->UsePublicKey($pubKey);

$bVerified = $rsa2->VerifyRawBd($bd);
print 'signature verified: ' . $bVerified . "\n";

// Show the original data:
print 'original data: ' . $bd->getEncoded('hex') . "\n";

?>