(Ruby) IMAP SSH Tunneling (Port Forwarding)

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

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

require 'chilkat'

# 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 != true)
    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 != true)
    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 != true)
    print imap.lastErrorText() + "\n";
    exit
end

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

# Select an IMAP mailbox
success = imap.SelectMailbox("Inbox")
if (success != true)
    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.

bUid = false
for i in 1 .. upperBound

    # email is a CkEmail
    email = imap.FetchSingle(i,bUid)
    if (imap.get_LastMethodSuccess() == false)
        print imap.lastErrorText() + "\n";
        exit

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

    end

end

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

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

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