(PHP ActiveX) Generate RSA Key and Sign a String

See more RSA Examples

Demonstrates how to generate a new RSA public/private key pair and use it to generate a signature for a string. The (binary) digital signature is returned as a hexidecimalized string.

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.Rsa')
$rsa = new COM("Chilkat.Rsa");

// Generate a 2048-bit RSA key.
$success = $rsa->GenerateKey(2048);

// Return the signature in hex.
$rsa->EncodingMode = 'hex';

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

// Sign the SHA256 hash of the string.
$hexSig = $rsa->signStringENC($strData,'sha256');

print $hexSig . "\n";
print $rsa->LastErrorText . "\n";

// Now verify the signature:
$success = $rsa->VerifyStringENC($strData,'sha256',$hexSig);
if ($success == 1) {
    print 'Signature verified!' . "\n";
}
else {
    print $rsa->LastErrorText . "\n";
}

// Try it with an invalid signature:
$success = $rsa->VerifyStringENC($strData,'sha256','not a valid sig');
if ($success == 1) {
    print 'Signature verified!' . "\n";
}
else {
    print $rsa->LastErrorText . "\n";
}

// Try it with invalid data:
$success = $rsa->VerifyStringENC('Not the original data','sha256',$hexSig);
if ($success == 1) {
    print 'Signature verified!' . "\n";
}
else {
    print $rsa->LastErrorText . "\n";
}

// Try it with the wrong hash algorithm:
$success = $rsa->VerifyStringENC($strData,'sha-1',$hexSig);
if ($success == 1) {
    print 'Signature verified!' . "\n";
}
else {
    print $rsa->LastErrorText . "\n";
}


?>