(Tcl) IMAP over Multiple Hop SSH

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

Application => ServerSSH1 => ServerSSH2 => IMAPServer

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

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load ./chilkat.dll

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

set ssh1 [new_CkSsh]

# Connect directly to the 1st SSH server.
set success [CkSsh_Connect $ssh1 "serverssh1.com" 22]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh1]
    delete_CkSsh $ssh1
    exit
}

# Authenticate using login/password:
set success [CkSsh_AuthenticatePw $ssh1 "ssh1Login" "ssh1Password"]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh1]
    delete_CkSsh $ssh1
    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.
set ssh2 [new_CkSsh]

set success [CkSsh_ConnectThroughSsh $ssh2 $ssh1 "serverssh2.com" 22]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh2]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    exit
}

# Authenticate with ssh2...
set success [CkSsh_AuthenticatePw $ssh2 "ssh2Login" "ssh2Password"]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh2]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    exit
}

set imap [new_CkImap]

# Tell the IMAP object to connect to the IMAP server though the ssh2 tunnel (which itself is routed through ssh1).
# The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => IMAPServer
set success [CkImap_UseSsh $imap $ssh2]
if {$success != 1} then {
    puts [CkImap_lastErrorText $imap]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkImap $imap
    exit
}

CkImap_put_Ssl $imap 1
CkImap_put_Port $imap 993

# Connect to an IMAP server (through the multi-hop SSH tunnel)
set success [CkImap_Connect $imap "imap.someimapserver.com"]
if {$success != 1} then {
    puts [CkImap_lastErrorText $imap]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkImap $imap
    exit
}

# Login
set success [CkImap_Login $imap "myLogin" "myPassword"]
if {$success != 1} then {
    puts [CkImap_lastErrorText $imap]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkImap $imap
    exit
}

# Do whatever needs to be done...  for example,

# Create the new email folder (sub-mailbox) on the IMAP server.
# If no folder path is provided, the new folder is a sub-mailbox of Inbox.
set success [CkImap_CreateMailbox $imap "newFolder"]
if {$success != 1} then {
    puts [CkImap_lastErrorText $imap]
    delete_CkSsh $ssh1
    delete_CkSsh $ssh2
    delete_CkImap $imap
    exit
}

puts "Success."

# Close the connection with the IMAP server.  (This closes the tunnel through ssh2)
# The connection with ssh2 is still alive, and may be used for more connections.
set success [CkImap_Disconnect $imap]

# 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.
CkSsh_Disconnect $ssh2

CkSsh_Disconnect $ssh1

delete_CkSsh $ssh1
delete_CkSsh $ssh2
delete_CkImap $imap