(PHP ActiveX) CMS Sign Hash

Demonstrates how to use the SignHashENC method to sign a pre-computed hash. This method creates a CMS signature (PKCS7 detached signature).

This example requires Chilkat v9.5.0.90 or later.

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 requires 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.Crypt2')
$crypt = new COM("Chilkat.Crypt2");

// Create the hash to be signed...
$crypt->HashAlgorithm = 'sha256';
$crypt->EncodingMode = 'base64';
$crypt->Charset = 'utf-8';
// Create the SHA256 hash of a string using the utf-8 byte representation.
// Return the hash as base64.
$base64Hash = $crypt->hashStringENC('This is the string to be hashed');

// Load a certificate for signing.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Cert')
$cert = new COM("Chilkat.Cert");
$success = $cert->LoadPfxFile('qa_data/pfx/cert_test123.pfx','test123');
if ($success == 0) {
    print $cert->LastErrorText . "\n";
    exit;
}

$crypt->SetSigningCert($cert);

// Sign the hash to create a base64 CMS signature (which does not contain the original data).
// We can get the signature in a single line of base64 by specifying "base64", or 
// we can get multi-line base64 by specifying "base64_mime".
$crypt->EncodingMode = 'base64_mime';
$base64CmsSig = $crypt->signHashENC($base64Hash,'sha256','base64');
if ($crypt->LastMethodSuccess == 0) {
    print $crypt->LastErrorText . "\n";
    exit;
}

// Note: In the above call to SignHashENC, the encoding of the returned CMS signature is specified by the EncodingMode property.
// However, the encoding of the passed-in hash is indicated by the 3rd argument.

print 'CMS Signature: ' . $base64CmsSig . "\n";

?>