(Tcl) SSH Tunnel for Database Connection (such as ADO, ODBC, JDBC, etc.)

Demonstrates how to create an SSH tunneling client in a background thread of your application. This makes it possible to SSH tunnel database connections without the need for separate software (such as PuTTY) to be running.

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load ./chilkat.dll

set chilkatGlob [new_CkGlobal]

set success [CkGlobal_UnlockBundle $chilkatGlob "Anything for 30-day trial."]
if {$success != 1} then {
    puts [CkGlobal_lastErrorText $chilkatGlob]
    delete_CkGlobal $chilkatGlob
    exit
}

set tunnel [new_CkSshTunnel]

set sshHostname "sftp.example.com"
set sshPort 22

# Connect to an SSH server and establish the SSH tunnel:
set success [CkSshTunnel_Connect $tunnel $sshHostname $sshPort]
if {$success != 1} then {
    puts [CkSshTunnel_lastErrorText $tunnel]
    delete_CkGlobal $chilkatGlob
    delete_CkSshTunnel $tunnel
    exit
}

# Authenticate with the SSH server via a login/password
# or with a public key.  
# This example demonstrates SSH password authentication.
set success [CkSshTunnel_AuthenticatePw $tunnel "mySshLogin" "mySshPassword"]
if {$success != 1} then {
    puts [CkSshTunnel_lastErrorText $tunnel]
    delete_CkGlobal $chilkatGlob
    delete_CkSshTunnel $tunnel
    exit
}

# The destination host/port is the database server.
# The DestHostname may be the domain name or 
# IP address (in dotted decimal notation) of the database
# server.
CkSshTunnel_put_DestPort $tunnel 1433
CkSshTunnel_put_DestHostname $tunnel "myDbServer.com"

# Start accepting connections in a background thread.
# The SSH tunnels are autonomously run in a background
# thread.  There is one background thread for accepting
# connections, and another for managing the tunnel pool.
set listenPort 3316
set success [CkSshTunnel_BeginAccepting $tunnel $listenPort]
if {$success != 1} then {
    puts [CkSshTunnel_lastErrorText $tunnel]
    delete_CkGlobal $chilkatGlob
    delete_CkSshTunnel $tunnel
    exit
}

# At this point the app may connect to the database server through
# the SSH tunnel.  The database connection string would
# use "localhost" for the hostname and 3316 for the port.
# We're not going to show the database coding here,
# because it can vary depending on the API you're using
# (ADO, ODBC, OLE DB, etc. )

# This is where the application's database code would go...

# Stop the background listen/accept thread:
set waitForThreadExit 1
set success [CkSshTunnel_StopAccepting $tunnel $waitForThreadExit]
if {$success != 1} then {
    puts [CkSshTunnel_lastErrorText $tunnel]
    delete_CkGlobal $chilkatGlob
    delete_CkSshTunnel $tunnel
    exit
}

# Close the SSH tunnel (would also kick any remaining connected clients).
set success [CkSshTunnel_CloseTunnel $tunnel $waitForThreadExit]
if {$success != 1} then {
    puts [CkSshTunnel_lastErrorText $tunnel]
    delete_CkGlobal $chilkatGlob
    delete_CkSshTunnel $tunnel
    exit
}


delete_CkGlobal $chilkatGlob
delete_CkSshTunnel $tunnel