# K95RELAY (SAMPLE VERSION):
# Connects from K95 on Windows to an Internet host through an SSH relay
#
# Frank da Cruz
# The Open Source Kermit Project
# 10 April 2022
# Last update: Tue Apr 19 08:16:23 2022
#
# Windows Kermit-95-to-Internet-host connection via ssh relay.  Totally
# password driven: covers the case where both the relay and the Internet host
# are logged in to with a password.  Many other combinations are possible,
# e.g. public/private key exchange between the relay and the Internet host
# and/or between Windows and the relay.  The purpose of this script is simply
# to show that whatever the authentication method, the process can be scripted
# to mimic direct ssh login from Kermit 95 on Windows to the Internet host,
# even when the host doesn't recognize K95's ssh ciphers.
#
# When the script starts it prompts you for the two passwords.
#
# To adapt this script to your own home network, change the definitions
# in the first two sections and then make other adjustments as required.
#
# Note: The Internet server name (\m(fulltarget) is FICTIONAL.
#
#############################################################################

# User and computer names - CHANGE THESE
#
.relayuser = fdc                        # Username on relay
.targetuser = fdc                       # Username on Internet computer
.windowsuser = fdc                      # Username on Windows
.relay := \m(relayuser)-Ubuntu          # Relay hostname on local network
.fullrelay := \m(relay).home            # Full domain name of relay 
.fulltarget = server1.somehost.com      # Internet destination domain name

# Prompts, responses, and directories - CHANGE THESE IF NECESSARY
#
.relayshellprompt := [~]\32             # Relay shell prompt to wait for
.relaybadpassword := "Login incorrect"
.targetpassprompt := "Password: "
.defaultdirectory := C:/Users/\m(windowsuser)/tmp/ # Default Windows directory
.keepalive = 0              # Change this to 1 if you get "broken pipe" errors

# Other parameters derived from the user and computer names specified above
#
.shortrelay := \fupper(\fword(\m(relay),2,-)) # (for messages)
.shorttarget := \fword(\m(fulltarget),1)      # (for messages)
.banner := \fcapitalize(\m(shorttarget)) via \m(relay) # Banner for window
if \m(keepalive) {
    .sshcmd1 := ssh -l \m(targetuser) -e none 
    .sshcmd2 = -o TCPKeepAlive=yes -o ServerAliveCountMax=20
    .sshcmd3 = -o ServerAliveInterval=15
    .sshcommand := \m(sshcmd1) \m(sshcmd2) \m(sshcmd3) \m(fulltarget)
} else {
    .sshcommand := "ssh -l \m(targetuser) -e none \m(fulltarget)"
}
set title \m(banner)                    # Write window-frame banner
cd \m(defaultdirectory)                 # CD to desired Windows directory
if fail end 1 "cd \m(defaultdirectory) failed"

# Operational customizations - Colors, size, font, appearance, etc.
#
set command color white black           # Command screen color
set term color term lgray blue          # Terminal screen color

set terminal character-set utf8         # UTF-8 character encoding
set term apc unchecked                  # Application Program Command
set term width 80                       # Screen dimensions: 80 chars wide
set term height 45                      # and 45 lines high
set terminal font courier_new 10        # Font and size (points)
set gui window position 140 200         # Where to put window on PC screen
set terminal autodownload on            # Allow autodownload
set terminal scrollback 12000           # Allocate a big scrollback buffer

# Collect passwords...

undef _yy
while not def _yy {                     # Prompt for relay password
    askq _yy {\m(shortrelay) password: }
}
undef _zz
while not def _zz {                     # Prompt for Internet host password
    askq _zz {\m(shorttarget) password: }
}
# Connect to relay and log in
#
echo LOGGING IN TO RELAY \fupper(\m(shortrelay))...

set telnet auth type none               # Clear-text Telnet to relay
set host \m(fullrelay) telnet           # Connect but stay in command mode
input 10 Password:\32                   # Wait for password prompt
if success lineout \m(_yy)              # Send password
else end 1 "Relay password prompt not received"
minput 10 {\m(relayshellprompt)} {\m(relaybadpassword)}
switch \v(minput) {
  :0, echo, hangup, end 1 "Relay shell prompt not received"
  :1, break
  :2, echo, hangup, end 1 "FAILURE: Password not accepted"
  :default, end 1 "Problem with \m(shortrelay) login"
}
echo
echo \m(shortrelay) LOGIN OK...

# Connect from relay to target and log in.  Host behaviors vary as to what
# happens if the incorrect password is given so we just connect after sending
# the password and see what happened.
#
echo
echo LOGGING IN TO TARGET \fupper(\m(shorttarget))...
lineout \m(sshcommand)                  # Send ssh command to relay
input 10 \m(targetpassprompt)           # Wait for target password prompt
if fail end 1 "Target password prompt not received: \m(targetpassprompt)"
msleep 100                              # Brief pause
lineout \m(_zz)                         # Send password
echo
if open connection echo "\fupper(\m(shorttarget)) CONNECTION OK"
else end 1 "\fupper(\m(shorttarget)) CONNECTION FAILED"
connect                                 # Open terminal window to target
end 0                                   # return code 0 = success

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