defuse

Keybase proof

I hereby claim:

• I am defuse on github.
• I am defuse (https://keybase.io/defuse) on keybase.
• I have a public key whose fingerprint is BFAE 45EB D356 1D91 E3E2 56C2 DFA8 209C E967 8D5D

To claim this, I am signing this object:

defuse

Sketch of a security proof for BCRYPT(H(X)). This probably contains errors.

UPDATE: Only assume BCRYPT is collision resistant for X <= 72.

Define the BCRYPT-H(S, X) algorithm as follows:

UPDATE: Gah... the whole 'byte' thing isn't necessary at all. I originally
intended to pass *either* the actual X (with a zero byte prefix) or H(X) with
a 0x01 byte prefix, to bcrypt. I forgot to do that, and instead always passed
the hash with the byte prefix based on the length. The proof is still valid,

defuse

<?php

// WARNING: THIS IS EXPERIMENTAL CODE. DO NOT USE IT.

// --- binary to hex encoding ---

function sc_bin2hex($binary)
{
    $encoded = '';
    for ($i = 0; $i < strlen($binary); $i++) {

defuse

<?php

// THIS CODE IS EXPERIMENTAL. DO NOT USE IT.
// ALSO NOTE THERE IS NO ERROR CHECKING!

function side_channel_safe_encode($binary_string)
{
    // We only use 5 bits from every byte, so for 256 bits we need 52 bytes.
    $random = mcrypt_create_iv(52, MCRYPT_DEV_URANDOM);
    $printable_blind_key = '';

defuse

<?php
// [LIB - Crypt Functions]
// (c) 2005-2013 unix-world.org - all rights reserved
// code release 2013-05-30

//##################################################### PREVENT S EXECUTION
if(A_HEADER_EXEC_RUNTIME != 'NetVisionOpenSource') {
	die('This PHP script: `'.htmlspecialchars(@basename(__FILE__)).'` cannot be executed directly !');
} //end if
//#####################################################

defuse

#!/usr/bin/env ruby

# @DefuseSec's TrueCrypt Challenge Generator!
#
# This script generates a set of TrueCrypt "challenges." Volumes are created in
# different ways using secure 128-bit passwords to provide a challenge for
# anyone claiming TrueCrypt is backdoored. If there is a backdoor, then one
# should be able to use one of the published challenges to prove it.
#
# There are 5 different types of challenges:

defuse

str = "D0 1D 00 00 00 02 02 00 30 82 1D BD 06 09 2A 86 48 86 F7 0D 01 07 02 A0 82 1D AE 30 82 1D AA 02 01 01 31 0B 30 09 06 05 2B 0E 03 01 1A"

binary = str.split(" ").map { |x| x.to_i(16).chr }.join("")

0.upto(binary.length - 1) do |start|
  code = binary[start...binary.length]
  File.open("/tmp/foo.bin", "w") do |f| 
    f.write(code)
  end
  print `objdump -D -b binary -m i8086 -M intel /tmp/foo.bin`

defuse

lines = [
  "ABCDEFGHIJFG",
  "ABIKLAKGCMAIHDJACKNKCKNMDH",
  "MADHDPACLDHIKH",
  "AILDQIGCRIPACKNGHPACLDSDKLDPD",
  "ALCIHPIQTIDCEAPAHIG"
]

ct = lines.join("")

defuse

<?php
/*
 * This is the decoded version of Ballast Security's shell decoding challenge:
 * http://ballastsec.blogspot.ca/2013/01/first-of-many-encrypted-php-shell.html
 *
 * Original: http://pastebin.com/W92Q0Q9j
 * 
 * Decoding was done by @DefuseSec with a bit of help from @RiptideTempora.
 */
@error_reporting(0);

defuse

<?php

/* Escaping Challenge: Make a PHP script that (Z:) generates JavaScript code
 * that generates an HTML page containing a PHP script that (goto Z) */

/* The purpose of this challenge is to demonstrate how complicated escaping can
 * get when you're trying to combine 4 different languages (PHP, JavaScript,
 * HTML, and string literals). */

function js_string_escape($data)