(Chilkat2-Python) SSH Tunnel Inside another SSH Tunnel

Demonstrates how to create a TCP/IP socket connection through an SSH tunnel that is dynamic port forwarded through another SSH tunnel.

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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.

# This example requires Chilkat version 9.5.0.50 or greater.
tunnel = chilkat2.SshTunnel()

sshHostname = "www.ssh-serverA.com"
sshPort = 22

# Connect to an SSH server and establish the SSH tunnel:
success = tunnel.Connect(sshHostname,sshPort)
if (success != True):
    print(tunnel.LastErrorText)
    sys.exit()

# Authenticate with the SSH server via a login/password
# or with a public key.  
# This example demonstrates SSH password authentication.
success = tunnel.AuthenticatePw("mySshLogin","mySshPassword")
if (success != True):
    print(tunnel.LastErrorText)
    sys.exit()

# Indicate that the background SSH tunnel thread will behave as a SOCKS proxy server
# with dynamic port forwarding:
tunnel.DynamicPortForwarding = True

# We may optionally require that connecting clients authenticate with our SOCKS proxy server.
# To do this, set an inbound username/password.  Any connecting clients would be required to 
# use SOCKS5 with the correct username/password.
# If no inbound username/password is set, then our SOCKS proxy server will accept both
# SOCKS4 and SOCKS5 unauthenticated connections.

tunnel.InboundSocksUsername = "chilkat123"
tunnel.InboundSocksPassword = "password123"

# Start the listen/accept thread to begin accepting SOCKS proxy client connections.
# Listen on port 1080.
success = tunnel.BeginAccepting(1080)
if (success != True):
    print(tunnel.LastErrorText)
    sys.exit()

# Now that a background thread is running a SOCKS proxy server that forwards connections
# through an SSH tunnel, it is possible to use any Chilkat implemented protocol that is SOCKS capable,
# such as HTTP, POP3, SMTP, IMAP, FTP, Socket, etc.  The protocol may use SSL/TLS because the SSL/TLS
# will be passed through the SSH tunnel to the end-destination.  Also, any number of simultaneous
# connections may be routed through the SSH tunnel.

tunnelB = chilkat2.Socket()

# Indicate that the socket object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
tunnelB.SocksHostname = "localhost"
tunnelB.SocksPort = 1080
tunnelB.SocksVersion = 5
tunnelB.SocksUsername = "chilkat123"
tunnelB.SocksPassword = "password123"

# Open a new SSH tunnel through the existing tunnel (via what we treat as a SOCKS5 proxy,
# but it is actually a dynamic port-forwarded SSH tunnel).
success = tunnelB.SshOpenTunnel("www.ssh-serverB.com",22)
if (success != True):
    print(tunnelB.LastErrorText)
    sys.exit()

# Authenticate with ssh-serverB.com
success = tunnelB.SshAuthenticatePw("uname","pwd")
if (success != True):
    print(tunnelB.LastErrorText)
    sys.exit()

# OK, the SSH tunnel (within a tunnel) is setup.  Now open a channel within the tunnel.
# Once the channel is obtained, the Socket API may
# be used exactly the same as usual, except all communications
# are sent through the channel in the SSH tunnel.
# Any number of channels may be created from the same SSH tunnel.
# Multiple channels may coexist at the same time.

# Connect to an NIST time server and read the current date/time

maxWaitMs = 4000
useTls = False
# channel is a CkSocket
channel = tunnelB.SshOpenChannel("time-c.nist.gov",37,useTls,maxWaitMs)
if (tunnelB.LastMethodSuccess == False):
    print(tunnelB.LastErrorText)
    sys.exit()

# The time server will send a big-endian 32-bit integer representing
# the number of seconds since since 00:00 (midnight) 1 January 1900 GMT.
# The ReceiveInt32 method will receive a 4-byte integer, but returns
# True or False to indicate success.  If successful, the integer
# is obtained via the ReceivedInt property.
bigEndian = True
success = channel.ReceiveInt32(bigEndian)
if (success != True):
    print(channel.LastErrorText)

    sys.exit()

dt = chilkat2.CkDateTime()
dt.SetFromNtpTime(channel.ReceivedInt)

# Show the current local date/time
bLocalTime = True
print("Current local date/time: " + dt.GetAsRfc822(bLocalTime))

# Close the SSH channel.
success = channel.Close(maxWaitMs)
if (success != True):
    print(channel.LastErrorText)

    sys.exit()

# Stop the background listen/accept thread:
waitForThreadExit = True
success = tunnel.StopAccepting(waitForThreadExit)
if (success != True):
    print(tunnel.LastErrorText)
    sys.exit()

# Close the SSH tunnel (would also kick any remaining connected clients).
success = tunnel.CloseTunnel(waitForThreadExit)
if (success != True):
    print(tunnel.LastErrorText)
    sys.exit()