(CkPython) Socket Convert Existing TCP Connection to SSL/TLS

Demonstrates the Chilkat Socket ConvertToSsl method.

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import sys
import chilkat

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

sock = chilkat.CkSocket()

# --------------------------------------------------------------------
# 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.
useTls = True
port = 4243
maxWaitMs = 5000
success = sock.Connect("tcpbin.com",port,useTls,maxWaitMs)
if (success == False):
    print(sock.lastErrorText())
    sys.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())

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 False, so we only have a simple TCP connection after this call.
useTls = False
success = sock.Connect("tcpbin.com",port,useTls,maxWaitMs)
if (success == False):
    print(sock.lastErrorText())
    sys.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 == False):
    print(sock.lastErrorText())
    sys.exit()

# OK, we now have a TLS connection.
# Again, we can see the TLS version:
print("TLS version: " + sock.tlsVersion())

sock.Close(maxWaitMs)