Tcl

SSL Server Example

See more Socket/SSL/TLS Examples

Demonstrates how to create an SSL socket for accepting connections. This example is *very* simple in that it will create an SSL socket for accepting a single connection. It will read a message from the client, send a reply, and exit. Tcl

load ./chilkat.dll

set success 0

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

set listenSslSocket [new_CkSocket]

# An SSL server needs a digital certificate.  This example loads it from a PFX file.

# Create an instance of a certificate store object, load a PFX file,
# locate the certificate we need, and use it.
# (a PFX file may contain more than one certificate.)
set certStore [new_CkCertStore]

# The 1st argument is the filename, the 2nd arg is the 
# PFX file's password:
set success [CkCertStore_LoadPfxFile $certStore "chilkat.pfx" "test"]
if {$success == 0} then {
    puts [CkCertStore_lastErrorText $certStore]
    delete_CkSocket $listenSslSocket
    delete_CkCertStore $certStore
    exit
}

# Find the certificate to be used for SSL:
set jsonCN [new_CkJsonObject]

CkJsonObject_UpdateString $jsonCN "CN" "example.com"

set cert [new_CkCert]

set success [CkCertStore_FindCert $certStore $jsonCN $cert]
if {$success == 0} then {
    puts [CkCertStore_lastErrorText $certStore]
    delete_CkSocket $listenSslSocket
    delete_CkCertStore $certStore
    delete_CkJsonObject $jsonCN
    delete_CkCert $cert
    exit
}

# Use the certificate:
set success [CkSocket_InitSslServer $listenSslSocket $cert]
if {$success == 0} then {
    puts [CkSocket_lastErrorText $listenSslSocket]
    delete_CkSocket $listenSslSocket
    delete_CkCertStore $certStore
    delete_CkJsonObject $jsonCN
    delete_CkCert $cert
    exit
}

# Bind and listen on a port:
set myPort 8123
# Allow for a max of 5 queued connect requests.
set backLog 5
set success [CkSocket_BindAndListen $listenSslSocket $myPort $backLog]
if {$success == 0} then {
    puts [CkSocket_lastErrorText $listenSslSocket]
    delete_CkSocket $listenSslSocket
    delete_CkCertStore $certStore
    delete_CkJsonObject $jsonCN
    delete_CkCert $cert
    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 
# AcceptNext can hang indefinitely during the SSL handshake process. 
# Make sure these properties are set to appropriate values before calling AcceptNext.

# Set a 10 second max for waiting to read/write.  This is for the SSL/TLS handshake establishment.
CkSocket_put_MaxReadIdleMs $listenSslSocket 10000
CkSocket_put_MaxSendIdleMs $listenSslSocket 10000

# Accept a single client connection and establish the secure SSL/TLS channel:
set maxWaitMillisec 20000
set clientSock [new_CkSocket]

set success [CkSocket_AcceptNext $listenSslSocket $maxWaitMillisec $clientSock]
if {$success == 0} then {
    puts [CkSocket_lastErrorText $listenSslSocket]
    delete_CkSocket $listenSslSocket
    delete_CkCertStore $certStore
    delete_CkJsonObject $jsonCN
    delete_CkCert $cert
    delete_CkSocket $clientSock
    exit
}

# The client (in this example) is going to send a "Hello Server! -EOM-" 
# message.  Read it:
set receivedMsg [CkSocket_receiveUntilMatch $clientSock "-EOM-"]
if {[CkSocket_get_LastMethodSuccess $clientSock] == 0} then {
    puts [CkSocket_lastErrorText $clientSock]
    delete_CkSocket $listenSslSocket
    delete_CkCertStore $certStore
    delete_CkJsonObject $jsonCN
    delete_CkCert $cert
    delete_CkSocket $clientSock
    exit
}

puts "$receivedMsg"

# Send a "Hello Client! -EOM-" message:
set success [CkSocket_SendString $clientSock "Hello Client! -EOM-"]
if {$success == 0} then {
    puts [CkSocket_lastErrorText $clientSock]
    delete_CkSocket $listenSslSocket
    delete_CkCertStore $certStore
    delete_CkJsonObject $jsonCN
    delete_CkCert $cert
    delete_CkSocket $clientSock
    exit
}

# Close the connection with the client
# Wait a max of 20 seconds (20000 millsec)
set success [CkSocket_Close $clientSock 20000]

delete_CkSocket $listenSslSocket
delete_CkCertStore $certStore
delete_CkJsonObject $jsonCN
delete_CkCert $cert
delete_CkSocket $clientSock