(PHP ActiveX) Verfies an RSA Signature

See more Apple Keychain Examples

Verifies an RSA signature against the original data.

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

// The following data was signed by the following example:
// RSA Sign using a Private Key on a USB Token or Smartcard
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.BinData')
$bd = new COM("Chilkat.BinData");

for ($i = 0; $i <= 100; $i++) {
    $bd->AppendEncoded('000102030405060708090A0B0C0D0E0F','hex');
}

// Load the signature
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.BinData')
$bdSig = new COM("Chilkat.BinData");
$success = $bdSig->LoadFile('rsaSignatures/test1.sig');
if ($success == 0) {
    print 'Failed to load the RSA signature' . "\n";
    exit;
}

// Get the public key to be used for signature verification.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.PublicKey')
$pubKey = new COM("Chilkat.PublicKey");
$success = $pubKey->LoadFromFile('rsaKeys/chilkat-rsa-2048.pem');
if ($success == 0) {
    print $pubKey->LastErrorText . "\n";
    exit;
}

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Rsa')
$rsa = new COM("Chilkat.Rsa");
$rsa->ImportPublicKeyObj($pubKey);

// Verify the hash of the data against the signature.
// We pass in the original data.  Internally, the hash is generated
// and used to validate the signature.
// Validating the RSA signature means two things:  
// (1) the original data is exactly what was signed, and 
// (2) it was signed by the owner of the RSA private key.
$success = $rsa->VerifyBd($bd,'sha256',$bdSig);

if ($success == 0) {
    print $rsa->LastErrorText . "\n";
    print 'Signature invalid.' . "\n";
}
else {
    print 'Signature valid.' . "\n";
}


?>