(Chilkat2-Python) Accept TLS Connection with Client Authentication

Demonstrates how to accept a TLS connection requiring client authentication. This is the case where the TLS client sends a certificate. It is also known as "Two-Way SSL".

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import sys
import chilkat2

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

listenSslSocket = chilkat2.Socket()

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

cert = chilkat2.Cert()
# The 1st argument is the file path, the 2nd arg is the 
# PFX file's password:
success = cert.LoadPfxFile("chilkat.pfx","test")
if (success != True):
    print(cert.LastErrorText)
    sys.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")

# Use the certificate:
success = listenSslSocket.InitSslServer(cert)
if (success != True):
    print(listenSslSocket.LastErrorText)
    sys.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)
    sys.exit()

# If accepting an SSL/TLS connection, the SSL handshake is part of the connection
# establishment process. This involves a few back-and-forth messages between the 
# client and server to establish algorithms and a shared key to create the secure 
# channel. The sending and receiving of these messages are governed by the 
# MaxReadIdleMs and MaxSendIdleMs properties. If these properties are set to 0 
# (and this is the default unless changed by your application), then the 
# AcceptNextConnection can hang indefinitely during the SSL handshake process. 
# Make sure these properties are set to appropriate values before calling AcceptNextConnection.

# Set a 10 second max for waiting to read/write.  This is for the SSL/TLS handshake establishment.
listenSslSocket.MaxReadIdleMs = 10000
listenSslSocket.MaxSendIdleMs = 10000

# Accept a single client connection and establish the secure SSL/TLS channel:

maxWaitMillisec = 20000
# clientSock is a CkSocket
clientSock = listenSslSocket.AcceptNextConnection(maxWaitMillisec)
if (listenSslSocket.LastMethodSuccess == False):
    print(listenSslSocket.LastErrorText)
    sys.exit()

# The client (in this example) is going to send a "Hello Server! -EOM-" 
# message.  Read it:
receivedMsg = clientSock.ReceiveUntilMatch("-EOM-")
if (clientSock.LastMethodSuccess != True):
    print(clientSock.LastErrorText)
    sys.exit()

print(receivedMsg)

# Send a "Hello Client! -EOM-" message:
success = clientSock.SendString("Hello Client! -EOM-")
if (success != True):
    print(clientSock.LastErrorText)
    sys.exit()

# Close the connection with the client
# Wait a max of 20 seconds (20000 millsec)
success = clientSock.Close(20000)