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Tcl

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

See more SSH Tunnel Examples

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.

Chilkat Tcl Downloads

Tcl

load ./chilkat.dll

set success 0

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

set success 0

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_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_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_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_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_CkSshTunnel $tunnel
    exit
}


delete_CkSshTunnel $tunnel