PHP Requires Chilkat v11.0.0+

Verify Opaque Signature and Retrieve Signing Certificates

See more Digital Signatures Examples

Demonstrates how to verify a PCKS7 opaque digital signature (signed data), extract the original file/data, and then extract the certificate(s) that were used to sign. Chilkat2 PHP

<?php

use Chilkat2\BinData;
use Chilkat2\Cert;
use Chilkat2\CertChain;
use Chilkat2\Crypt2;

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

$crypt = new Crypt2();

// Verify a PKCS7 signed-data (opaque signature) file and extract the original content to a file.
try {
    $crypt->VerifyP7M('qa_data/p7m/opaqueSig.p7', 'qa_output/originalData.dat');

    // Alternatively, we can do it in memory...
    $binData = new BinData();
    $binData->LoadFile('qa_data/p7m/opaqueSig.p7');
    // Your app should check for success, but we'll skip the check for brevity..

    // If verified, the signature is unwrapped and binData is replaced with the original data that was signed.
    $crypt->OpaqueVerifyBd($binData);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// For our testing, we signed some text, so we can get it from the binData..
echo "Original Data:\n";
echo $binData->GetString('utf-8'), "\n";

// After any method call that verifies a signature, the crypt object will contain the certificate(s)
// that were used for signing (assuming the X.509 certs were available in the signature, which is typically the case).

// Get each signing certificate, and build the certificate chain for each.
$cert = new Cert();
$certChain = new CertChain();
$numCerts = $crypt->NumSignerCerts;
$i = 0;
while ($i < $numCerts) {
    $crypt->LastSignerCert($i, $cert);
    echo $cert->SubjectDN, "\n";

    try {
        $cert->BuildCertChain($certChain);
    } catch (\Chilkat2\Exception $e) {
        echo $e->getMessage(), "\n";
        exit;
    }

    $i = $i + 1;
}