(Ruby) IMAP SSH Tunneling (Port Forwarding)

Demonstrates how to setup and use an SSH tunnel for IMAP.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

success = false

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

imap = Chilkat::CkImap.new()

# The SSH hostname may be a hostname or an 
# IP address, such as "192.168.1.108".
# The port is typically 22 (the standard port for SSH).
sshHostname = "www.mysshserver.com"
sshPort = 22

# Connect to an SSH server and establish the SSH tunnel:
success = imap.SshOpenTunnel(sshHostname,sshPort)
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# Authenticate with the SSH server via a login/password
# or with a public key.
# This example demonstrates SSH password authentication.
# Note: This is not authenticating with the IMAP server, it is
# for authenticating with the SSH server, which is separate.
success = imap.SshAuthenticatePw("mySshLogin","mySshPassword")
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# OK, the SSH tunnel is setup.  The IMAP component may
# be used exactly the same as usual, except all communications
# are sent through the SSH tunnel.

# Connect to an IMAP server via the SSH tunnel.
# Because the SSH tunnel has been previously setup,
# this does not establish a direct connection with the IMAP
# server.  It directs the SSH server to establish the connection.

# In this example, the IMAP server requires SSL/TLS.  The TLS connection
# will be enclosed within the SSH tunnel.
imap.put_Ssl(true)
imap.put_Port(993)
success = imap.Connect("imap.my-imap-server.com")
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# Authenticate with the IMAP server via the SSH tunnel.
success = imap.Login("myLogin","myPassword")
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# Select an IMAP mailbox
success = imap.SelectMailbox("Inbox")
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# How many messages in Inbox?
msgCount = imap.get_NumMessages()
if (msgCount == 0)
    print "No messages found." + "\n";
    exit
end

upperBound = 10
if (msgCount < upperBound)
    upperBound = msgCount
end

# Download up to the 1st 10 messages.
email = Chilkat::CkEmail.new()

bUid = false
for i in 1 .. upperBound

    success = imap.FetchEmail(false,i,bUid,email)
    if (success == false)
        print imap.lastErrorText() + "\n";
        exit
    end

    print email.ck_from() + "\n";
    print email.subject() + "\n";
    print "----" + "\n";
end

# Disconnect from the IMAP server.
# The SSH tunnel remains open.
success = imap.Disconnect()
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# It is possible to re-use the existing SSH tunnel for the next connection:
success = imap.Connect("imap.my-imap-server2.com")
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# Review the LastErrorText to see that the connection was made via the SSH tunnel:
print imap.lastErrorText() + "\n";

success = imap.Disconnect()
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

# Finally, close the SSH tunnel.
success = imap.SshCloseTunnel()
if (success == false)
    print imap.lastErrorText() + "\n";
    exit
end

print "IMAP SSH tunneling example completed." + "\n";