(PHP ActiveX) RSA Signature/Verify with .key and .cer

See more RSA Examples

Demonstrates how to use a .key file (private key) and digital certificate (.cer, public key) to create and verify an RSA signature.

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

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

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.PrivateKey')
$privKey = new COM("Chilkat.PrivateKey");

// Load the private key from an RSA .key file:
$success = $privKey->LoadPemFile('privateKey.key');
if ($success != 1) {
    print $privKey->LastErrorText . "\n";
    exit;
}

// Get the private key in XML format:
$privKeyXml = $privKey->getXml();

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

// Import the private key into the RSA component:
$success = $rsa->ImportPrivateKey($privKeyXml);
if ($success != 1) {
    print $rsa->LastErrorText . "\n";
    exit;
}

// Create the signature as a hex string:
$rsa->EncodingMode = 'hex';

$strData = 'This is the string to be signed.';

// Sign the string using the sha-1 hash algorithm.
// Other valid choices are "md2", "sha256", "sha384",
// "sha512", and "md5".
$hexSig = $rsa->signStringENC($strData,'sha-1');

print $hexSig . "\n";

// Load a digital certificate from a .cer file:
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Cert')
$cert = new COM("Chilkat.Cert");

$success = $cert->LoadFromFile('myCert.cer');
if ($success != 1) {
    print $cert->LastErrorText . "\n";
    exit;
}

// pubKey is a Chilkat.PublicKey
$pubKey = $cert->ExportPublicKey();

// Now verify using a separate instance of the RSA object:
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Rsa')
$rsa2 = new COM("Chilkat.Rsa");

// Import the public key into the RSA object:
$success = $rsa2->ImportPublicKey($pubKey->getXml());
if ($success != 1) {
    print $rsa2->LastErrorText . "\n";
    exit;
}

// The signature is a hex string, so make sure the EncodingMode is correct:
$rsa2->EncodingMode = 'hex';

// Verify the signature:
$success = $rsa2->VerifyStringENC($strData,'sha-1',$hexSig);
if ($success != 1) {
    print $rsa2->LastErrorText . "\n";
    exit;
}

print 'Success.' . "\n";

?>