(PHP ActiveX) RSA Sign String using Private Key of Certificate Type A3 (smart card / token)

Demonstrates RSA signing a string using the private key of a certificate type A3 (smart card, token).

Note: This is a Windows-only example.

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

// First get the A3 certificate that was installed on the Windows system.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.CertStore')
$certStore = new COM("Chilkat.CertStore");

$thumbprint = '12c1dd8015f3f03f7b1fa619dc24e2493ca8b4b2';

// This is specific to Windows because it is opening the Windows Current-User certificate store.
$bReadOnly = 1;
$success = $certStore->OpenCurrentUserStore($bReadOnly);
if ($success != 1) {
    print $certStore->LastErrorText . "\n";
    exit;
}

// Find the certificate with the desired thumbprint
// (There are many ways to locate a certificate.  This example chooses to find by thumbprint.)
// cert is a Chilkat.Cert
$cert = $certStore->FindCertBySha1Thumbprint($thumbprint);
if ($certStore->LastMethodSuccess != 1) {
    print 'Failed to find the certificate.' . "\n";
    exit;
}

print 'Found: ' . $cert->SubjectCN . "\n";

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

// Provide the cert's private key
$bUsePrivateKey = 1;
$success = $rsa->SetX509Cert($cert,$bUsePrivateKey);

if ($success != 1) {
    print $rsa->LastErrorText . "\n";
    exit;
}

// Return the RSA signature in base64 encoded form.
$rsa->EncodingMode = 'base64';

// Sign the utf-8 byte representation of the string.
$rsa->Charset = 'utf-8';

// You can also choose other hash algorithms, such as SHA-1.
$sigBase64 = $rsa->signStringENC('text to sign','SHA-256');
if ($rsa->LastMethodSuccess != 1) {
    print $rsa->LastErrorText . "\n";
    exit;
}

print 'Base64 signature: ' . $sigBase64 . "\n";

?>