Perl

Socket Convert Existing TCP Connection to SSL/TLS

Demonstrates the Chilkat Socket ConvertToSsl method. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

my $sock = Chilkat2::Socket->new;

# --------------------------------------------------------------------
# This example uses the public TCP/TLS echo service at https://tcpbin.com/
# --------------------------------------------------------------------

# The echo server at tcpbin.com expects to receive TCP connections on port 4242, and TLS connections on port 4243.
# We could simply connect to port 4243 using TLS like this.
# However, further below, this example shows how to initially make a TCP connection, and then convert the connection to TLS.
my $useTls = 1;
my $port = 4243;
my $maxWaitMs = 5000;
my $success = $sock->Connect('tcpbin.com', $port, $useTls, $maxWaitMs);
if (!$success) {
    print $sock->LastErrorText, "\n";
    exit;
}

# OK, we have a TLS connection.
# Note: The server chooses the TLS protocol version.
# We can see the version of the TLS connection that was established:
print 'TLS version: ', $sock->TlsVersion, "\n";

$sock->Close($maxWaitMs);

# ---------------------------------------------------------------------
# Now we'll do the same, except first we connect to port 4243 using TCP,
# and then convert the connection to TLS.
#
# This may seem pointless, and it is for the case w/ this server.  However, there could be situations
# where you're interacting with a server of some kind where there is a need to convert to/from TLS.
# (This is common internal to many protocols, such as SMTP, IMAP, FTP, etc., and it is often called "explicit" SSL/TLS)

# Connect again, except this time useTls is 0, so we only have a simple TCP connection after this call.
$useTls = 0;
$success = $sock->Connect('tcpbin.com', $port, $useTls, $maxWaitMs);
if (!$success) {
    print $sock->LastErrorText, "\n";
    exit;
}

# Convert the existing TCP connection to TLS.
# (The method name uses "SSL" because long ago, at the time of initial development, TLS 1.0 did not yet exist.)
$success = $sock->ConvertToSsl();
if (!$success) {
    print $sock->LastErrorText, "\n";
    exit;
}

# OK, we now have a TLS connection.
# Again, we can see the TLS version:
print 'TLS version: ', $sock->TlsVersion, "\n";

$sock->Close($maxWaitMs);