(CkPython) SMTP over Multiple Hop SSH

Demonstrates how to send email (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => SmtpServer

The ConnectThroughSsh and UseSsh methods are added in Chilkat version 9.5.0.55 to accomplish this task.

Chilkat Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

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

ssh1 = chilkat.CkSsh()

# Connect directly to the 1st SSH server.
success = ssh1.Connect("serverssh1.com",22)
if (success != True):
    print(ssh1.lastErrorText())
    sys.exit()

# Authenticate using login/password:
success = ssh1.AuthenticatePw("ssh1Login","ssh1Password")
if (success != True):
    print(ssh1.lastErrorText())
    sys.exit()

# Connect through the 1st SSH connection to reach a 2nd SSH server.
# Note: Any number of SSH connections may be simultaneously tunneled through a single
# existing SSH connection.
ssh2 = chilkat.CkSsh()
success = ssh2.ConnectThroughSsh(ssh1,"serverssh2.com",22)
if (success != True):
    print(ssh2.lastErrorText())
    sys.exit()

# Authenticate with ssh2...
success = ssh2.AuthenticatePw("ssh2Login","ssh2Password")
if (success != True):
    print(ssh2.lastErrorText())
    sys.exit()

mailman = chilkat.CkMailMan()

# Tell the mailman object to connect to the SMTP server though the ssh2 tunnel (which itself is routed through ssh1).
# The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => SMTPServer
success = mailman.UseSsh(ssh2)
if (success != True):
    print(mailman.lastErrorText())
    sys.exit()

# Set the SMTP server.
mailman.put_SmtpHost("smtp.someserver.com")

# Set the SMTP login/password (if required)
mailman.put_SmtpUsername("myUsername")
mailman.put_SmtpPassword("myPassword")

# Create a new email object
email = chilkat.CkEmail()

email.put_Subject("This is a test")
email.put_Body("This is a test")
email.put_From("Chilkat Support <support@chilkatsoft.com>")
success = email.AddTo("Chilkat Admin","admin@chilkatsoft.com")

success = mailman.SendEmail(email)
if (success != True):
    print(mailman.lastErrorText())
    sys.exit()

# Close the connection with the server.  This closes the tunnel through ssh2.
success = mailman.CloseSmtpConnection()
if (success != True):
    print("Connection to SMTP server not closed cleanly.")

print("Mail Sent!")

# Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
# The connection with ssh1 is still alive, and may be used for more connections.
ssh2.Disconnect()

ssh1.Disconnect()