#!/bin/sh

# works best on busybox sh

set -efux -o pipefail


## Create a temporary working folder
mkdir -p "tmp/"
cd "tmp/"

## Prepare datasets
curl -L "https://zhouhanc.github.io/malware-discoverer/blocklist.csv.zip" -o "source.zip"
curl -L "https://s3-us-west-1.amazonaws.com/umbrella-static/top-1m.csv.zip" -o "top-1m-umbrella.zip"
curl -L "https://tranco-list.eu/top-1m.csv.zip" -o "top-1m-tranco.zip"
curl -L "https://oisd.nl/excludes.php" -o "oisd-exclude.html"

## Parse URLs
unzip -p "source.zip" | \
dos2unix | \
tr "[:upper:]" "[:lower:]" | \
sed "/^domain,/d" | \
cut -f 1 -d ',' > "source-domains.txt"


## Parse the Umbrella 1 Million
unzip -p "top-1m-umbrella.zip" | \
dos2unix | \
tr "[:upper:]" "[:lower:]" | \
# Parse domains only
cut -f 2 -d "," | \
grep -F "." | \
# Remove www.
sed "s/^www\.//g" | \
sort -u > "top-1m-umbrella.txt"

## Parse the Tranco 1 Million
unzip -p "top-1m-tranco.zip" | \
dos2unix | \
tr "[:upper:]" "[:lower:]" | \
# Parse domains only
cut -f 2 -d "," | \
grep -F "." | \
# Remove www.
sed "s/^www\.//g" | \
sort -u > "top-1m-tranco.txt"

cp "../src/exclude.txt" "."

## Parse oisd exclusion list
cat "oisd-exclude.html" | \
# https://stackoverflow.com/a/47600828
xmlstarlet format --recover --html 2>/dev/null | \
xmlstarlet select --html --template --value-of '//a' | \
## Append new line https://unix.stackexchange.com/a/31955
sed '$a\' > "oisd-exclude.txt"

# Merge Umbrella, Traco and self-maintained top domains
cat "top-1m-umbrella.txt" "top-1m-tranco.txt" "exclude.txt" "oisd-exclude.txt" | \
sort -u > "top-1m-well-known.txt"


## Exclude popular domains
cat "source-domains.txt" | \
# grep match whole line
grep -Fx -vf "top-1m-well-known.txt" > "pup-notop-domains.txt"


## Merge malware domains and URLs
CURRENT_TIME="$(date -R -u)"
FIRST_LINE="! Title: PUP Domains Blocklist\n! Description: Block domains that host potentially unwanted programs (PUP)"
SECOND_LINE="! Updated: $CURRENT_TIME"
THIRD_LINE="! Expires: 1 day (update frequency)"
FOURTH_LINE="! Homepage: https://gitlab.com/curben/pup-filter"
FIFTH_LINE="! License: https://gitlab.com/curben/pup-filter#license"
SIXTH_LINE="! Source: https://github.com/zhouhanc/malware-discoverer"
ANNOUNCEMENT_1="\n! 2021/01/08: There has been a major change to the mirrors, check the repo for the new mirrors."
ANNOUNCEMENT_2="! The main download link \"curben.gitlab.io/malware-filter/\" _is not affected_."
COMMENT_UBO="$FIRST_LINE\n$SECOND_LINE\n$THIRD_LINE\n$FOURTH_LINE\n$FIFTH_LINE\n$SIXTH_LINE\n$ANNOUNCEMENT_1\n$ANNOUNCEMENT_2"

mkdir -p "../public/"

cat "pup-notop-domains.txt" | \
sort | \
sed '1 i\'"$COMMENT_UBO"'' > "../public/pup-filter.txt"


# Adguard Home
cat "pup-notop-domains.txt" | \
sort | \
sed -e "s/^/||/g" -e "s/$/^/g" | \
sed '1 i\'"$COMMENT_UBO"'' | \
sed "1s/Blocklist/Blocklist (AdGuard Home)/" > "../public/pup-filter-agh.txt"


# Adguard browser extension
cat "pup-notop-domains.txt" | \
sort | \
sed -e "s/^/||/g" -e "s/$/\$all/g" | \
sed '1 i\'"$COMMENT_UBO"'' | \
sed "1s/Blocklist/Blocklist (AdGuard)/" > "../public/pup-filter-ag.txt"


# Vivaldi
cat "pup-notop-domains.txt" | \
sort | \
sed -e "s/^/||/g" -e "s/$/\$document/g" | \
sed '1 i\'"$COMMENT_UBO"'' | \
sed "1s/Blocklist/Blocklist (Vivaldi)/" > "../public/pup-filter-vivaldi.txt"


## Hash comment
# awk + head is a workaround for sed prepend
COMMENT=$(printf "$COMMENT_UBO" | sed "s/^!/#/g" | awk '{printf "%s\\n", $0}' | head -c -2)

cat "pup-notop-domains.txt" | \
sort | \
sed '1 i\'"$COMMENT"'' > "../public/pup-filter-domains.txt"


## Hosts file blocklist
cat "pup-notop-domains.txt" | \
sed "s/^/0.0.0.0 /g" | \
sed '1 i\'"$COMMENT"'' | \
sed "1s/Domains/Hosts/" > "../public/pup-filter-hosts.txt"


## Dnsmasq-compatible blocklist
cat "pup-notop-domains.txt" | \
sed "s/^/address=\//g" | \
sed "s/$/\/0.0.0.0/g" | \
sed '1 i\'"$COMMENT"'' | \
sed "1s/Blocklist/dnsmasq Blocklist/" > "../public/pup-filter-dnsmasq.conf"


## BIND-compatible blocklist
cat "pup-notop-domains.txt" | \
sed 's/^/zone "/g' | \
sed 's/$/" { type master; notify no; file "null.zone.file"; };/g' | \
sed '1 i\'"$COMMENT"'' | \
sed "1s/Blocklist/BIND Blocklist/" > "../public/pup-filter-bind.conf"


## DNS Response Policy Zone (RPZ)
CURRENT_UNIX_TIME="$(date +%s)"
RPZ_SYNTAX="\n\$TTL 30\n@ IN SOA rpz.curben.gitlab.io. hostmaster.rpz.curben.gitlab.io. $CURRENT_UNIX_TIME 86400 3600 604800 30\n NS localhost.\n"

cat "pup-notop-domains.txt" | \
sed "s/$/ CNAME ./g" | \
sed '1 i\'"$RPZ_SYNTAX"'' | \
sed '1 i\'"$COMMENT"'' | \
sed "s/^#/;/g" | \
sed "1s/Blocklist/RPZ Blocklist/" > "../public/pup-filter-rpz.conf"


## Unbound-compatible blocklist
cat "pup-notop-domains.txt" | \
sed 's/^/local-zone: "/g' | \
sed 's/$/" always_nxdomain/g' | \
sed '1 i\'"$COMMENT"'' | \
sed "1s/Blocklist/Unbound Blocklist/" > "../public/pup-filter-unbound.conf"


## dnscrypt-proxy blocklists
# name-based
cat "pup-notop-domains.txt" | \
sed '1 i\'"$COMMENT"'' | \
sed "1s/Domains/Names/" > "../public/pup-filter-dnscrypt-blocked-names.txt"

## Currently there are no IP entries
# # IPv4-based
# cat "phishing-notop-domains.txt" | \
# sort | \
# grep -E "^([0-9]{1,3}[\.]){3}[0-9]{1,3}$" | \
# sed '1 i\'"$COMMENT"'' | \
# sed "1s/Domains/IPs/" > "../public/phishing-filter-dnscrypt-blocked-ips.txt"


## IE blocklist
COMMENT_IE="msFilterList\n$COMMENT\n: Expires=1\n#"

cat "pup-notop-domains.txt" | \
sed "s/^/-d /g" | \
sed '1 i\'"$COMMENT_IE"'' | \
sed "2s/Domains Blocklist/Hosts Blocklist (IE)/" > "../public/pup-filter.tpl"


set +x

## Snort & Suricata rulesets
rm -f "../public/pup-filter-snort2.rules" \
  "../public/pup-filter-snort3.rules" \
  "../public/pup-filter-suricata.rules"

SID="300000001"
while read DOMAIN; do
  SN_RULE="alert tcp \$HOME_NET any -> \$EXTERNAL_NET [80,443] (msg:\"pup-filter PUP website detected\"; flow:established,from_client; content:\"GET\"; http_method; content:\"$DOMAIN\"; content:\"Host\"; http_header; classtype:web-application-activity; sid:$SID; rev:1;)"

  SN3_RULE="alert http \$HOME_NET any -> \$EXTERNAL_NET any (msg:\"pup-filter PUP website detected\"; http_header:field host; content:\"$DOMAIN\",nocase; classtype:web-application-activity; sid:$SID; rev:1;)"

  SR_RULE="alert http \$HOME_NET any -> \$EXTERNAL_NET any (msg:\"pup-filter PUP website detected\"; flow:established,from_client; http.method; content:\"GET\"; http.host; content:\"$DOMAIN\"; classtype:web-application-activity; sid:$SID; rev:1;)"

  echo "$SN_RULE" >> "../public/pup-filter-snort2.rules"
  echo "$SN3_RULE" >> "../public/pup-filter-snort3.rules"
  echo "$SR_RULE" >> "../public/pup-filter-suricata.rules"

  SID=$(( $SID + 1 ))
done < "pup-notop-domains.txt"


set -x

sed -i '1 i\'"$COMMENT"'' "../public/pup-filter-snort2.rules"
sed -i "1s/Blocklist/Snort2 Ruleset/" "../public/pup-filter-snort2.rules"

sed -i '1 i\'"$COMMENT"'' "../public/pup-filter-snort3.rules"
sed -i "1s/Blocklist/Snort3 Ruleset/" "../public/pup-filter-snort3.rules"

sed -i '1 i\'"$COMMENT"'' "../public/pup-filter-suricata.rules"
sed -i "1s/Blocklist/Suricata Ruleset/" "../public/pup-filter-suricata.rules"


## Clean up artifacts
rm "source.zip" "source-domains.txt" "top-1m-umbrella.zip" "top-1m-umbrella.txt" "top-1m-tranco.txt" "oisd-exclude.html" "oisd-exclude.txt"


cd ../