zapret/blockcheck.sh
2021-12-12 23:34:04 +03:00

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Executable File

#!/bin/sh
EXEDIR="$(dirname "$0")"
EXEDIR="$(cd "$EXEDIR"; pwd)"
ZAPRET_BASE="$EXEDIR"
[ -n "$QNUM" ] || QNUM=59780
[ -n "$TPPORT" ] || TPPORT=993
[ -n "$TPWS_UID" ] || TPWS_UID=1
[ -n "$NFQWS" ] || NFQWS="$ZAPRET_BASE/nfq/nfqws"
[ -n "$DVTWS" ] || DVTWS="$ZAPRET_BASE/nfq/dvtws"
[ -n "$TPWS" ] || TPWS="$ZAPRET_BASE/tpws/tpws"
[ -n "$MDIG" ] || MDIG="$ZAPRET_BASE/mdig/mdig"
[ -n "$DESYNC_MARK" ] || DESYNC_MARK=0x40000000
DOMAIN=rutracker.org
CURL_MAX_TIME=5
MIN_TTL=1
MAX_TTL=12
HDRTEMP=/tmp/zapret-hdr.txt
ECHON="echo -n"
IPFW_RULE_NUM=1
IPFW_DIVERT_PORT=59780
DNSCHECK_DNS="8.8.8.8 1.1.1.1 77.88.8.8"
DNSCHECK_DOM="pornhub.com putinhuylo.com rutracker.org nnmclub.to protonmail.com"
DNSCHECK_DIG1=/tmp/dig1.txt
DNSCHECK_DIG2=/tmp/dig2.txt
DNSCHECK_DIGS=/tmp/digs.txt
exists()
{
which $1 >/dev/null 2>/dev/null
}
killwait()
{
# $1 - signal (-9, -2, ...)
# $2 - pid
kill $1 $2
# suppress job kill message
wait $2 2>/dev/null
}
exitp()
{
local A
echo
echo press enter to continue
read A
exit $1
}
read_yes_no()
{
# $1 - default (Y/N)
local A
read A
[ -z "$A" ] || ([ "$A" != "Y" ] && [ "$A" != "y" ] && [ "$A" != "N" ] && [ "$A" != "n" ]) && A=$1
[ "$A" = "Y" ] || [ "$A" = "y" ] || [ "$A" = "1" ]
}
ask_yes_no()
{
# $1 - default (Y/N or 0/1)
# $2 - text
local DEFAULT=$1
[ "$1" = "1" ] && DEFAULT=Y
[ "$1" = "0" ] && DEFAULT=N
[ -z "$DEFAULT" ] && DEFAULT=N
$ECHON "$2 (default : $DEFAULT) (Y/N) ? "
read_yes_no $DEFAULT
}
ask_yes_no_var()
{
# $1 - variable name for answer : 0/1
# $2 - text
local DEFAULT
eval DEFAULT="\$$1"
if ask_yes_no "$DEFAULT" "$2"; then
eval $1=1
else
eval $1=0
fi
}
require_root()
{
echo \* checking privileges
[ $(id -u) -ne "0" ] && {
echo root is required
exists sudo && exec sudo "$0"
exists su && exec su -c "$0"
echo su or sudo not found
exitp 2
}
}
IPT()
{
$IPTABLES -C "$@" >/dev/null 2>/dev/null || $IPTABLES -I "$@"
}
IPT_DEL()
{
$IPTABLES -C "$@" >/dev/null 2>/dev/null && $IPTABLES -D "$@"
}
IPFW_ADD()
{
ipfw -qf add $IPFW_RULE_NUM "$@"
}
IPFW_DEL()
{
ipfw -qf delete $IPFW_RULE_NUM
}
check_system()
{
echo \* checking system
UNAME=$(uname)
case "$UNAME" in
Linux)
PKTWS="$NFQWS"
PKTWSD=nfqws
;;
FreeBSD)
PKTWS="$DVTWS"
PKTWSD=dvtws
;;
*)
echo $UNAME not supported
exitp 5
esac
}
freebsd_module_loaded()
{
# $1 - module name
kldstat | grep -q "${1}.ko"
}
freebsd_modules_loaded()
{
# $1,$2,$3, ... - module names
while [ -n "$1" ]; do
freebsd_module_loaded $1 || return 1
shift
done
return 0
}
check_prerequisites()
{
echo \* checking prerequisites
[ -x "$PKTWS" ] && [ -x "$TPWS" ] && [ -x "$MDIG" ] || {
echo $PKTWS or $TPWS or $MDIG is not available. run \"$ZAPRET_BASE/install_bin.sh\" or make -C \"$ZAPRET_BASE\"
exitp 6
}
local progs='curl'
case "$UNAME" in
Linux)
progs="$progs iptables ip6tables"
;;
FreeBSD)
progs="$progs ipfw"
freebsd_modules_loaded ipfw ipdivert || {
echo ipfw or ipdivert kernel module not loaded
exitp 6
}
[ "$(sysctl -qn net.inet.ip.fw.enable)" = 0 -o "$(sysctl -qn net.inet6.ip6.fw.enable)" = 0 ] && {
echo ipfw is disabled. use : ipfw enable firewall
exitp 6
}
;;
esac
for prog in $progs; do
exists $prog || {
echo $prog does not exist. please install
exitp 6
}
done
if exists nslookup; then
LOOKUP=nslookup
elif exists host; then
LOOKUP=host
else
echo nslookup or host does not exist. please install
exitp 6
fi
}
curl_supports_tls13()
{
curl --tlsv1.3 -Is -o /dev/null http://$LOCALHOST_IPT:65535 2>/dev/null
# return code 2 = init failed. likely bad command line options
[ $? = 2 ] && return 1
# curl can have tlsv1.3 key present but ssl library without TLS 1.3 support
# this is online test because there's no other way to trigger library incompatibility case
curl --tlsv1.3 -Is -o /dev/null https://w3.org 2>/dev/null
[ $? != 4 ]
}
curl_supports_tlsmax()
{
# supported only in OpenSSL
curl --version | grep -q OpenSSL || return 1
# supported since curl 7.54
curl --tls-max 1.2 -Is -o /dev/null http://$LOCALHOST_IPT:65535 2>/dev/null
# return code 2 = init failed. likely bad command line options
[ $? != 2 ]
}
hdrfile_http_code()
{
# $1 - hdr file
sed -nre '1,1 s/^HTTP\/1\.[0,1] ([0-9]+) .*$/\1/p' "$1"
}
hdrfile_location()
{
# $1 - hdr file
# some DPIs return CRLF line ending
tr -d '\015' <"$1" | sed -nre 's/^[Ll][Oo][Cc][Aa][Tt][Ii][Oo][Nn]:[ \t]*([^ \t]*)[ \t]*$/\1/p'
}
curl_test_http()
{
# $1 - ip version : 4/6
# $2 - domain name
local code loc
curl -${1}SsD "$HDRTEMP" --max-time $CURL_MAX_TIME $CURL_OPT "http://$2" -o /dev/null 2>&1 || {
code=$?
rm -f "$HDRTEMP"
return $code
}
code=$(hdrfile_http_code "$HDRTEMP")
[ "$code" = 301 -o "$code" = 302 -o "$code" = 307 -o "$code" = 308 ] && {
loc=$(hdrfile_location "$HDRTEMP")
echo "$loc" | grep -qE "^https?://.*$2(/|$)" ||
echo "$loc" | grep -vqE '^https?://' || {
echo suspicious redirection to : $loc
rm -f "$HDRTEMP"
return 254
}
}
rm -f "$HDRTEMP"
return 0
}
curl_test_https_tls12()
{
# $1 - ip version : 4/6
# $2 - domain name
# prevent using QUIC if available in curl
# do not use tls 1.3 to make sure server certificate is not encrypted
curl -${1}Ss --max-time $CURL_MAX_TIME $CURL_OPT --http1.1 --tlsv1.2 $TLSMAX12 "https://$2" -o /dev/null 2>&1
}
curl_test_https_tls13()
{
# $1 - ip version : 4/6
# $2 - domain name
# prevent using QUIC if available in curl
# force TLS1.3 mode
curl -${1}Ss --max-time $CURL_MAX_TIME $CURL_OPT --http1.1 --tlsv1.3 $TLSMAX13 "https://$2" -o /dev/null 2>&1
}
pktws_ipt_prepare()
{
# $1 - port
case "$UNAME" in
Linux)
IPT POSTROUTING -t mangle -p tcp --dport $1 -m mark ! --mark $DESYNC_MARK/$DESYNC_MARK -j NFQUEUE --queue-num $QNUM
;;
FreeBSD)
IPFW_ADD divert $IPFW_DIVERT_PORT tcp from any to any 80,443 out not diverted not sockarg
;;
esac
}
pktws_ipt_unprepare()
{
# $1 - port
case "$UNAME" in
Linux)
IPT_DEL POSTROUTING -t mangle -p tcp --dport $1 -m mark ! --mark $DESYNC_MARK/$DESYNC_MARK -j NFQUEUE --queue-num $QNUM
;;
FreeBSD)
IPFW_DEL
;;
esac
}
tpws_ipt_prepare()
{
# $1 - port
case "$UNAME" in
Linux)
IPT OUTPUT -t nat -p tcp --dport $1 -m owner ! --uid-owner $TPWS_UID -j DNAT --to $LOCALHOST_IPT:$TPPORT
;;
FreeBSD)
if [ "$IPV" = 4 ]; then
IPFW_ADD fwd 127.0.0.1,$TPPORT tcp from me to any 80,443 proto ip4 not uid $TPWS_UID
else
IPFW_ADD fwd ::1,$TPPORT tcp from me to any 80,443 proto ip6 not uid $TPWS_UID
fi
;;
esac
}
tpws_ipt_unprepare()
{
# $1 - port
case "$UNAME" in
Linux)
IPT_DEL OUTPUT -t nat -p tcp --dport $1 -m owner ! --uid-owner $TPWS_UID -j DNAT --to $LOCALHOST_IPT:$TPPORT
;;
FreeBSD)
IPFW_DEL
;;
esac
}
pktws_start()
{
case "$UNAME" in
Linux)
"$NFQWS" --dpi-desync-fwmark=$DESYNC_MARK --qnum=$QNUM "$@" >/dev/null &
;;
FreeBSD)
"$DVTWS" --port=$IPFW_DIVERT_PORT "$@" >/dev/null &
;;
esac
PID=$!
}
tpws_start()
{
"$TPWS" --uid $TPWS_UID:$TPWS_UID --bind-addr=$LOCALHOST --port=$TPPORT "$@" >/dev/null &
PID=$!
# give some time to initialize
sleep 1
}
ws_kill()
{
[ -z "$PID" ] || {
killwait -9 $PID 2>/dev/null
PID=
}
}
curl_test()
{
# $1 - test function
# $2 - domain
$1 $IPV $2 && {
echo '!!!!! AVAILABLE !!!!!'
return 0
}
local code=$?
if [ $code = 254 ]; then
echo UNAVAILABLE
else
echo UNAVAILABLE code=$code
fi
return $code
}
ws_curl_test()
{
# $1 - ws start function
# $2 - test function
# $3 - domain
# $4,$5,$6, ... - ws params
local code ws_start=$1 testf=$2 dom=$3
shift
shift
shift
$ws_start "$@"
curl_test $testf $dom
code=$?
ws_kill
return $code
}
tpws_curl_test()
{
# $1 - test function
# $2 - domain
# $3,$4,$5, ... - tpws params
echo - checking tpws $3 $4 $5 $6 $7 $8 $9
ws_curl_test tpws_start "$@"
}
pktws_curl_test()
{
# $1 - test function
# $2 - domain
# $3,$4,$5, ... - nfqws/dvtws params
echo - checking $PKTWSD $3 $4 $5 $6 $7 $8 $9
ws_curl_test pktws_start "$@"
}
pktws_check_domain_bypass()
{
# $1 - test function
# $2 - encrypted test : 1/0
# $3 - domain
local strategy tests='fake' ttls s sec="$2" found
[ "$sec" = 0 ] && {
for s in '--hostcase' '--hostspell=hoSt' '--hostnospace' '--domcase'; do
pktws_curl_test $1 $3 $s && strategy="${strategy:-$s}"
done
}
s="--dpi-desync=split2"
if pktws_curl_test $1 $3 $s; then
strategy="${strategy:-$s}"
else
tests="$tests split fake,split2 fake,split"
[ "$sec" = 0 ] && {
s="$s --hostcase"
pktws_curl_test $1 $3 $s && strategy="${strategy:-$s}"
}
for pos in 1 2 4 5 10 50 100; do
s="--dpi-desync=split2 --dpi-desync-split-pos=$pos"
if pktws_curl_test $1 $3 $s; then
strategy="${strategy:-$s}"
break
else
[ "$sec" = 0 ] && {
s="$s --hostcase"
pktws_curl_test $1 $3 $s && strategy="${strategy:-$s}"
}
fi
done
fi
s="--dpi-desync=disorder2"
if pktws_curl_test $1 $3 $s; then
strategy="${strategy:-$s}"
else
tests="$tests disorder fake,disorder2 fake,disorder"
fi
ttls=$(seq -s ' ' $MIN_TTL $MAX_TTL)
for desync in $tests; do
found=0
for ttl in $ttls; do
s="--dpi-desync=$desync --dpi-desync-ttl=$ttl"
pktws_curl_test $1 $3 $s && {
found=1
strategy="${strategy:-$s}"
break
}
done
[ "$sec" = 1 ] && [ "$found" = 0 ] && {
for ttl in $ttls; do
s="--dpi-desync=$desync --dpi-desync-ttl=$ttl --wssize 1:6"
pktws_curl_test $1 $3 $s && {
found=1
strategy="${strategy:-$s}"
break
}
done
}
for fooling in badsum md5sig badseq; do
s="--dpi-desync=$desync --dpi-desync-fooling=$fooling"
if pktws_curl_test $1 $3 $s ; then
strategy="${strategy:-$s}"
[ "$fooling" = "md5sig" ] && echo 'WARNING ! although md5sig fooling worked it will not work on all sites. it typically works only on linux servers.'
else
[ "$sec" = 1 ] && {
s="$s --wssize 1:6"
pktws_curl_test $1 $3 $s && {
strategy="${strategy:-$s}"
[ "$fooling" = "md5sig" ] && echo 'WARNING ! although md5sig fooling worked it will not work on all sites. it typically works only on linux servers.'
}
}
fi
done
done
[ "$sec" = 1 ] && {
s="--wssize 1:6"
pktws_curl_test $1 $3 $s && strategy="${strategy:-$s}"
}
echo
if [ -n "$strategy" ]; then
echo "!!!!! working strategy found : $PKTWSD $strategy !!!!!"
return 0
else
echo 'working strategy not found'
return 1
fi
}
tpws_check_domain_bypass()
{
# $1 - test function
# $2 - encrypted test : 1/0
# $3 - domain
local s strategy sec="$2"
if [ "$sec" = 0 ]; then
for s in '--hostcase' '--hostspell=hoSt' '--split-http-req=method' '--split-http-req=method --hostcase' '--split-http-req=host' '--split-http-req=host --hostcase' \
'--hostdot' '--hosttab' '--hostnospace' '--methodspace' '--methodeol' '--unixeol' \
'--hostpad=1024' '--hostpad=2048' '--hostpad=4096' '--hostpad=8192' '--hostpad=16384'; do
tpws_curl_test $1 $3 $s && strategy="${strategy:-$s}"
done
else
for pos in 1 2 3 4 5 10 50 100; do
s="--split-pos=$pos"
tpws_curl_test $1 $3 $s && {
strategy="${strategy:-$s}"
break
}
done
fi
echo
if [ -n "$strategy" ]; then
echo "!!!!! working strategy found : tpws $strategy !!!!!"
return 0
else
echo 'working strategy not found'
return 1
fi
}
check_domain()
{
# $1 - test function
# $2 - port
# $3 - encrypted test : 1/0
# $4 - domain
local code
echo
echo \* $1 $4
# in case was interrupted before
pktws_ipt_unprepare $2
tpws_ipt_unprepare $2
ws_kill
echo "- checking without DPI bypass"
curl_test $1 $4 && return
code=$?
for c in 1 2 3 4 6 27 ; do
[ $code = $c ] && return
done
echo
echo preparing tpws redirection
tpws_ipt_prepare $2
tpws_check_domain_bypass $1 $3 $4
echo clearing tpws redirection
tpws_ipt_unprepare $2
echo
echo preparing $PKTWSD redirection
pktws_ipt_prepare $2
pktws_check_domain_bypass $1 $3 $4
echo clearing $PKTWSD redirection
pktws_ipt_unprepare $2
}
check_domain_http()
{
# $1 - domain
check_domain curl_test_http 80 0 $1
}
check_domain_https_tls12()
{
# $1 - domain
check_domain curl_test_https_tls12 443 1 $1
}
check_domain_https_tls13()
{
# $1 - domain
check_domain curl_test_https_tls13 443 1 $1
}
configure_ip_version()
{
if [ "$IPV" = 6 ]; then
IPTABLES=ip6tables
LOCALHOST=::1
LOCALHOST_IPT=[::1]
else
IPTABLES=iptables
LOCALHOST=127.0.0.1
LOCALHOST_IPT=127.0.0.1
fi
}
configure_curl_opt()
{
TLSMAX12=
TLSMAX13=
curl_supports_tlsmax && {
TLSMAX12="--tls-max 1.2"
TLSMAX13="--tls-max 1.3"
}
TLS13=
curl_supports_tls13 && TLS13=1
}
ask_params()
{
echo
echo NOTE ! this test should be run with zapret or any other bypass software disabled, without VPN
$ECHON "test this domain (default: $DOMAIN) : "
local dom
read dom
[ -n "$dom" ] && DOMAIN=$dom
$ECHON "ip protocol version - 4 or 6 (default: 4) : "
read IPV
[ -n "$IPV" ] || IPV=4
[ "$IPV" = 4 -o "$IPV" = 6 ] || {
echo invalid ip version. should be 4 or 6.
exitp 1
}
configure_ip_version
configure_curl_opt
ENABLE_HTTP=1
ask_yes_no_var ENABLE_HTTP "check http"
[ -n "$TLSMAX12" ] || echo "WARNING ! your curl version or TLS library does not support tls-max option. TLS 1.2 tests may use TLS 1.3+ protocols"
ENABLE_HTTPS_TLS12=1
ask_yes_no_var ENABLE_HTTPS_TLS12 "check https tls 1.2"
ENABLE_HTTPS_TLS13=0
echo
if [ -n "$TLS13" ]; then
echo "TLS 1.3 is the new standard for encrypted communications over TCP"
echo "its the most important feature for DPI bypass is encrypted TLS ServerHello"
echo "more and more sites enable TLS 1.3 but still there're many sites with only TLS 1.2 support"
echo "with TLS 1.3 more DPI bypass strategies can work but they may not apply to all sites"
echo "if a strategy works with TLS 1.2 it will also work with TLS 1.3"
echo "if nothing works with TLS 1.2 this test may find TLS1.3 only strategies"
echo "make sure that $DOMAIN supports TLS 1.3 otherwise all test will return an error"
ask_yes_no_var ENABLE_HTTPS_TLS13 "check https tls 1.3"
else
echo "installed curl version does not support TLS 1.3 . tests disabled."
fi
IGNORE_CA=0
CURL_OPT=
[ $ENABLE_HTTPS_TLS13 = 1 -o $ENABLE_HTTPS_TLS12 = 1 ] && {
echo
echo on limited systems like openwrt CA certificates might not be installed to preserve space
echo in such a case curl cannot verify server certificate and you should either install ca-bundle or disable verification
echo however disabling verification will break https check if ISP does MitM attack and substitutes server certificate
ask_yes_no_var IGNORE_CA "do not verify server certificate"
[ "$IGNORE_CA" = 1 ] && CURL_OPT=-k
}
}
pingtest()
{
ping -c 1 -W 1 $1 >/dev/null
}
dnstest()
{
# $1 - dns server. empty for system resolver
"$LOOKUP" w3.org $1 >/dev/null 2>/dev/null
}
find_working_public_dns()
{
for dns in $DNSCHECK_DNS; do
pingtest $dns && dnstest $dns && {
PUBDNS=$dns
return 0
}
done
return 1
}
lookup4()
{
# $1 - domain
# $2 - DNS
case "$LOOKUP" in
nslookup)
nslookup $1 $2 | sed -n '/Name:/,$p' | grep ^Address | grep -oE '([0-9]{1,3}\.){3}[0-9]{1,3}'
;;
host)
host -t A $1 $2 | grep "has address" | grep -oE '([0-9]{1,3}\.){3}[0-9]{1,3}'
;;
esac
}
check_dns_spoof()
{
# $1 - domain
# $2 - public DNS
echo $1 | "$MDIG" --family=4 >"$DNSCHECK_DIG1"
lookup4 $1 $2 >"$DNSCHECK_DIG2"
# check whether system resolver returns anything other than public DNS
grep -qvFf "$DNSCHECK_DIG2" "$DNSCHECK_DIG1"
}
check_dns_cleanup()
{
rm -f "$DNSCHECK_DIG1" "$DNSCHECK_DIG2" "$DNSCHECK_DIGS" 2>/dev/null
}
check_dns()
{
local C1 C2
echo \* checking DNS
[ -f "$DNSCHECK_DIGS" ] && rm -f "$DNSCHECK_DIGS"
dnstest || {
echo -- DNS is not working. It's either misconfigured or blocked or you don't have inet access.
return 1
}
echo system DNS is working
if find_working_public_dns ; then
echo comparing system resolver to public DNS : $PUBDNS
for dom in $DNSCHECK_DOM; do
if check_dns_spoof $dom $PUBDNS ; then
echo $dom : MISMATCH
echo -- system resolver :
cat "$DNSCHECK_DIG1"
echo -- $PUBDNS :
cat "$DNSCHECK_DIG2"
check_dns_cleanup
echo -- POSSIBLE DNS HIJACK DETECTED. ZAPRET WILL NOT HELP YOU IN CASE DNS IS SPOOFED !!!
echo -- DNS CHANGE OR DNSCRYPT MAY BE REQUIRED
return 1
else
echo $dom : OK
cat "$DNSCHECK_DIG1" >>"$DNSCHECK_DIGS"
fi
done
else
echo no working public DNS was found. looks like public DNS blocked.
for dom in $DNSCHECK_DOM; do echo $dom; done | "$MDIG" --threads=10 --family=4 >"$DNSCHECK_DIGS"
fi
echo checking resolved IP uniqueness for : $DNSCHECK_DOM
echo censor\'s DNS can return equal result for multiple blocked domains.
C1=$(wc -l <"$DNSCHECK_DIGS")
C2=$(sort -u "$DNSCHECK_DIGS" | wc -l)
[ "$C1" -eq 0 ] &&
{
echo -- DNS is not working. It's either misconfigured or blocked or you don't have inet access.
check_dns_cleanup
return 1
}
[ "$C1" = "$C2" ] ||
{
echo system dns resolver has returned equal IPs for some domains checked above \($C1 total, $C2 unique\)
echo non-unique IPs :
sort "$DNSCHECK_DIGS" | uniq -d
echo -- POSSIBLE DNS HIJACK DETECTED. ZAPRET WILL NOT HELP YOU IN CASE DNS IS SPOOFED !!!
echo -- DNSCRYPT MAY BE REQUIRED
check_dns_cleanup
return 1
}
echo all resolved IPs are unique
echo -- DNS looks good
echo -- NOTE this check is Russia targeted. In your country other domains may be blocked.
check_dns_cleanup
return 0
}
sigint()
{
# make sure we are not in a middle state that impacts connectivity
echo
echo terminating...
[ -n "$IPV" ] && {
tpws_ipt_unprepare 80
tpws_ipt_unprepare 443
pktws_ipt_unprepare 80
pktws_ipt_unprepare 443
}
ws_kill
exitp 1
}
check_system
check_prerequisites
require_root
check_dns
ask_params
PID=
trap 'sigint' 2
[ "$ENABLE_HTTP" = 1 ] && check_domain_http $DOMAIN
[ "$ENABLE_HTTPS_TLS12" = 1 ] && check_domain_https_tls12 $DOMAIN
[ "$ENABLE_HTTPS_TLS13" = 1 ] && check_domain_https_tls13 $DOMAIN
trap - 2
exitp 0