Perl

Upgrade a Plain TCP Connection to TLS

Demonstrates Socket.ConvertToSsl, which upgrades an already-connected plain TCP socket to TLS by performing a client-side TLS handshake over the existing connection.

Background. This supports STARTTLS-style upgrades, where a protocol begins in plaintext and switches to TLS at a defined point. Perform the protocol-specific negotiation first, then call ConvertToSsl.

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Perl

use chilkat();

$success = 0;

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

#  Connect as plain TCP (no TLS yet).
$bTls = 0;
$maxWaitMs = 5000;
$success = $socket->Connect("example.com",5000,$bTls,$maxWaitMs);
if ($success == 0) {
    print $socket->lastErrorText() . "\r\n";
    exit;
}

#  At the point where the application protocol permits a STARTTLS-style upgrade, perform any required
#  negotiation, then upgrade the existing connection to TLS with a client-side handshake.
$success = $socket->ConvertToSsl();
if ($success == 0) {
    print $socket->lastErrorText() . "\r\n";
    exit;
}

print "Connection upgraded to TLS." . "\r\n";