(Perl) 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 Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

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

$listenSslSocket = chilkat::CkSocket->new();

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

$cert = chilkat::CkCert->new();
$success = $cert->LoadPfxFile("qa_data/serverCert/myServerCert.pfx","pfx_password");
if ($success != 1) {
    print $cert->lastErrorText() . "\r\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 != 1) {
    print $listenSslSocket->lastErrorText() . "\r\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 != 1) {
    print $listenSslSocket->lastErrorText() . "\r\n";
    exit;
}

# Accept the next incoming connection.
$maxWaitMillisec = 20000;
# clientSock is a Socket
$clientSock = $listenSslSocket->AcceptNextConnection($maxWaitMillisec);
if ($listenSslSocket->get_LastMethodSuccess() == 0) {
    print $listenSslSocket->lastErrorText() . "\r\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 . "\r\n";

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

    $i = $i + 1;
}

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