#! /bin/ksh
#Set your hostname after this variable
fqdn=gopher.zcrayfish.soy
oldfqdn=zcrayfish.dyndns.org
cr=$(printf '\r')
crlf=$(printf '\r\n')
null=$(printf '')
securityheaders () {
printf '%s\15\12' "Strict-Transport-Security: max-age=31536000;" \
"Content-Security-Policy: default-src *.zcrayfish.soy; object-src *.zcrayfish.soy; base-uri *.zcrayfish.soy;" \
"X-Frame-Options: DENY" \
"X-XSS-Protection: 1; mode=block" \
"Referrer-Policy: no-referrer"
}
error301 () {
printf '%s\15\12' "HTTP/1.0 301 Moved Permanently" \
"Location: https://$fqdn$obj"; \
"Content-Type: text/plain; charset=utf-8" \
"Date: $date" \
"Server: gopher to http gateway at $fqdn" \
"Connection: close" \
"" \
"HTTP/1.0 301 Moved permanently" \
"http://$oldfqdn$obj"; \
"Might be found at:" \
"https://$fqdn$obj"; \
"" \
"gopher to http gateway at $fqdn"
}
error400 () {
printf '%s\15\12' "HTTP/1.0 400 Bad Request" \
"Content-Type: text/plain; charset=utf-8" \
"Allow: GET" \
"Date: $date" \
"Server: gopher to http gateway at $fqdn" \
"Connection: close" \
"" \
"HTTP/1.0 400 Bad Request" \
"Request could not be understood - bad syntax" \
"" \
"gopher to http gateway at $fqdn"
exit
}
error404 () {
printf '%s\15\12' "HTTP/1.0 404 Not Found" \
"Content-Type: text/plain; charset=utf-8" \
"Date: $date" \
"Server: gopher to http gateway at $fqdn" \
"Connection: close" \
"" \
"HTTP/1.0 404 Not Found" \
"'$obj' doesn't exist!" \
"This resource cannot be located." \
"" \
"gopher to http gateway at $fqdn"
}
error501 () {
printf '%s\15\12' "HTTP/1.0 501 Not Implemented" \
"Content-Type: text/plain; charset=utf-8" \
"Allow: GET" \
"Date: $date" \
"Server: gopher to http gateway at $fqdn" \
"Connection: close" \
"" \
"HTTP/1.0 501 Not Implemented" \
"This error has accoured for one of the following reasons:" \
" *This server only implements the GET method (e.g. your browser sent a HEAD or PUT)" \
" *This server, while acting as a gateway or proxy, does not support CSO queries." \
"" \
"gopher to http gateway at $fqdn"
exit
}
# Gather request
read -t 30 -r cmd obj proto badclient
#Did we time out... If so just exit, HTTP 1.0 does not have a timeout code
test "$?" != "0" && exit
# See if request is a GET, if not, throw it away
test "$cmd" != 'GET' && error501 && exit
# Likewise ignore invalid gets too.
test ! -z "$badclient" && error400 && exit
# If it all looks good, find out what they want
filename="$(printf "%s" "$obj" | sed -e 's/%2c/,/' -e 's/%20/ /')"
# Gather headers, assume headers are done when we see CRLF or weird crap
while /bin/true; do
read -t 300 -r header headervalue port
test "$header" = "$cr" && break
test "$header" = "$crlf" && break
test "$header" = "$null" && break
header=$(echo "$header" | tr '[:upper:]' '[:lower:]')
test "$header" = "host:" && host="$headervalue"
#header="$(printf "$header" | sed -e 's/://')"
#declare -a $header
#printf -v "${header}" '%s' "${headervalue}" 2> /dev/null
done
#old FQDN? Redirect them!
zdo=$(echo "$host" | grep -i zcrayfish.dyndns.org)
test ! -z "$zdo" && error301 && exit
date="$(date -u +'%a, %d %b %Y %H:%M:%S GMT')"
#Step4
case "$filename" in
/favicon.ico)
error404
;;
/sitemap*|/robots.txt|/.well-known*)
printf '%s\15\12' "HTTP/1.0 200 OK" \
"Date: $date" \
"Server: gopher to http gateway at $fqdn" \
"Connection: close" \
""
lynx -anonymous -source "gopher://$fqdn/0/$filename";
;;
/2*)
error501
;;
/7*)
printf '%s\15\12' "HTTP/1.0 200 OK" \
"Content-Type: text/html; charset=utf-8" \
"Date: $date" \
"Server: gopher to http gateway at $fqdn" \
"Connection: close" \
"" \
'<!DOCTYPE html PUBLIC "-//IETF//DTD HTML 2.0//EN">' \
'<title></title>' \
"<form action='$fqdn$filename' method='get'>" \
'<p>This is a searchable gopher index. Enter search keywords:<input type="text" name="httpsearch"></p></form>'
;;
/debug*)
printf '%s\15\12' "HTTP/1.0 200 OK" \
"Content-Type: text/plain" \
""
set
;;
###START OF DUMB / NON-INTELLIGENT GOPHER TYPES###
/[04569IMPdghps]*)
printf '%s\15\12' "HTTP/1.0 200 OK"
case "$filename" in
/0/stylesheet.css)
printf '%s\15\12' "Content-Type: text/css" \
"X-Content-Type-Options: nosniff"
;;
/0*)
printf '%s\15\12' "Content-Type: text/plain" \
"X-Content-Type-Options: nosniff"
;;
/4*)
printf '%s\15\12' "Content-Type: application/mac-binhex40" \
"X-Content-Type-Options: nosniff"
;;
/5*)
printf '%s\15\12' "Content-Type: application/octet-stream" \
"X-Content-Type-Options: nosniff"
;;
/6*)
printf '%s\15\12' "Content-Type: message/rfc822" \
"X-Content-Type-Options: nosniff"
;;
/9*)
printf '%s\15\12' "Content-Type: application/octet-stream" \
"X-Content-Type-Options: nosniff"
;;
/I*)
printf '%s\15\12' "Content-Type: image/jpeg" \
"X-Content-Type-Options: nosniff"
;;
/M*)
printf '%s\15\12' "Content-Type: message/rfc822" \
"X-Content-Type-Options: nosniff"
;;
/P*)
printf '%s\15\12' "Content-Type: application/pdf" \
"X-Content-Type-Options: nosniff"
;;
/d*)
printf '%s\15\12' "Content-Type: application/pdf"
"X-Content-Type-Options: nosniff" \
;;
/g*)
printf '%s\15\12' "Content-Type: image/gif" \
"X-Content-Type-Options: nosniff"
;;
/h*)
printf '%s\15\12' "Content-Type: text/html" \
"X-Content-Type-Options: nosniff"
;;
/p*)
printf '%s\15\12' "Content-Type: image/png" \
"X-Content-Type-Options: nosniff"
;;
/s*)
printf '%s\15\12' "Content-Type: application/octet-stream"
;;
esac
securityheaders
printf '%s\15\12' "Date: $date" \
"Server: gopher to http gateway at $fqdn" \
"Connection: close" \
""
lynx -anonymous -dump -source "gopher://$fqdn:70$filename"
;;
###END OF DUMB / NON-INTELLIGENT GOPHER TYPES###
*)
printf '%s\15\12' 'HTTP/1.0 200 OK' \
'Content-Type: text/html; charset=utf-8' \
"Date: $date" \
"Server: gopher to http gateway at $fqdn"
securityheaders
printf '%s\15\12' 'Connection: close' \
'X-Content-Type-Options: nosniff' \
'' \
'<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 1//EN">'
# '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">'
lynx -anonymous -dump -source "gopher://$fqdn:70$filename" | \
tidy -in -w 0 -cn --doctype omit --show-errors 0 --show-warnings 0 --quiet 1 --uppercase-tags 1 --uppercase-attributes 1 --char-encoding utf8 | \
# sed -e 's/<A HREF="\/\/'$fqdn':70/<A HREF="\/\/'$fqdn'/g'
sed -e 's/<A HREF="\/\//<A HREF="gopher:\/\//g' -e 's/<A HREF="gopher:\/\/'$fqdn':70/<A HREF="\/\/'$fqdn'/g' -e '/<HEAD>/a <LINK REL="STYLESHEET" HREF="//gopher.zcrayfish.soy/0/stylesheet.css">'
# sed -e 's/<A HREF="\/\/'$fqdn':70/<A HREF="http:\/\/'$fqdn'/g' -e 's/<A HREF="\/\//<A HREF="gopher:\/\//g'
;;
esac
exit
Response:
text/plain