Dynamic A-Record DNS Updater for united-domains.de (OpenWRT/LEDE)

ddns_ud.sh

#!/bin/sh
# requires: wget, ca-certificates, grep
#rm /tmp/cookies.txt

cookiefile="/tmp/cookies.txt"

#domain should contain "domain_id:record_id"
domain_id=$(echo $domain | tr ":" "\n" | sed -n "1p")
record_id=$(echo $domain | tr ":" "\n" | sed -n "2p")

#csrf tokens for login + language xmlhttprequest required to login (nice try blocking my API access, UD)
loginpage=$(/usr/bin/wget --save-cookies $cookiefile --keep-session-cookies --delete-after -qO- "https://www.united-domains.de/login/")
csrf=$(echo "$loginpage" | /usr/bin/grep -oP -m 2 "(?<=<input type=\"hidden\" name=\"csrf\" value=\")[^\"]*(?=\"( /)?>)" | tail -1)
csrfmeta=$(echo "$loginpage" | /usr/bin/grep -oP -m 1 "(?<=<meta name=\"csrf\" content=\")[^\"]*(?=\"( /)?>)")
csrfscript=$(echo "$loginpage" | /usr/bin/grep -oP -m 1 "(?<=\"CSRF_TOKEN\":\")[^\"]*(?=\")")
/usr/bin/wget --load-cookies $cookiefile --save-cookies $cookiefile --keep-session-cookies --delete-after --post-data "language=en-US" --header="HTTP-X-CSRF-TOKEN: $csrfmeta" --header="X-Csrf-Token: $csrfscript" --header="X-Requested-With: XMLHttpRequest" -qO- "https://www.united-domains.de/set-user-language"

ipv4=$1

#login
echo 'login'
loginresp=$(/usr/bin/wget --load-cookies $cookiefile --save-cookies $cookiefile --keep-session-cookies --post-data "csrf=$csrf&email=$username&pwd=$password&selector=login&loginBtn=Login" -qO- "https://www.united-domains.de/login/")

#get current dns record json object & modify ip
record=$(/usr/bin/wget --load-cookies $cookiefile --save-cookies $cookiefile --keep-session-cookies -qO- "https://www.united-domains.de/pfapi/dns/domain/$domain_id/records" | jsonfilter -e "$[\"data\"][\"A\"][@.id=$record_id]" | sed "s/ //g" | sed "s/\"address\":\"[0-9.]\+\"/\"address\":\"$ipv4\"/g")

payload="{\"record\":$record,\"domain_lock_state\":{\"domain_locked\":false,\"email_locked\":false}}"
url="https://www.united-domains.de/pfapi/dns/domain/$domain_id/records"

#send changes
output=$(/usr/bin/wget --load-cookies $cookiefile --method=PUT --header=Content-Type:application/json --header="Http-X-Csrf-Token: $csrf" --body-data=$payload -qO- $url 2>&1)
echo "UD answered: $output"
write_log 7 "UD answered:\n$output"

echo $output | /usr/bin/grep "$ipv4" >/dev/null 2>&1
success=$?
#write_log 7 "Retval: $success"
echo "Retval: $success"
return $success