(PHP Extension) Examine Client Certificates for an Accepted TLS Connection

Demonstrates how to access the client certificates for a TLS connection accepted by your application acting as the server.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

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

$listenSslSocket = new CkSocket();

// An SSL/TLS server needs a digital certificate.  This example loads it from a PFX file.
// This is the server's certificate.

$cert = new CkCert();
$success = $cert->LoadPfxFile('qa_data/serverCert/myServerCert.pfx','pfx_password');
if ($success != true) {
    print $cert->lastErrorText() . "\n";
    exit;
}

// To accept client client certificates in the TLS handshake,
// we must indicate a list of acceptable client certificate root CA DN's
// that are allowed.  (DN is an acronym for Distinguished Name.)
// Call AddSslAcceptableClientCaDn once for each acceptable CA DN.
// Here are a few examples so you can see the general format of a DN.
$listenSslSocket->AddSslAcceptableClientCaDn('C=SE, O=AddTrust AB, OU=AddTrust External TTP Network, CN=AddTrust External CA Root');
$listenSslSocket->AddSslAcceptableClientCaDn('O=Digital Signature Trust Co., CN=DST Root CA X3');

// Initialize with our server's TLS certificate.
$success = $listenSslSocket->InitSslServer($cert);
if ($success != true) {
    print $listenSslSocket->lastErrorText() . "\n";
    exit;
}

// Bind and listen on a port:
$myPort = 8123;
// Allow for a max of 5 queued connect requests.
$backLog = 5;
$success = $listenSslSocket->BindAndListen($myPort,$backLog);
if ($success != true) {
    print $listenSslSocket->lastErrorText() . "\n";
    exit;
}

// Accept the next incoming connection.
$maxWaitMillisec = 20000;
// clientSock is a CkSocket
$clientSock = $listenSslSocket->AcceptNextConnection($maxWaitMillisec);
if ($listenSslSocket->get_LastMethodSuccess() == false) {
    print $listenSslSocket->lastErrorText() . "\n";
    exit;
}

// Examine the client certs chain.  The 1st cert will be the client certificate, and
// the subsequent certs will be the certs in the chain of authentication.
$numClientCerts = $clientSock->get_NumReceivedClientCerts();
print 'numClientCerts = ' . $numClientCerts . "\n";

$i = 0;
while ($i < $numClientCerts) {
    // clientCert is a CkCert
    $clientCert = $clientSock->GetReceivedClientCert($i);
    print $clientCert->subjectDN() . "\n";

    $i = $i + 1;
}

// Close the connection with the client
$success = $clientSock->Close(1000);


?>