VNC challenge response password crack

[secured2k]

I attempted to reproduce the problem reported on similar hardware and found there seems to be some bug where using "00" in the hex charset will cause the search to fail. I could not reproduce this on Newer CPUs or nVidia GPU hardware so I assume the problem is specific to the Intel HD 4000 hardware or driver or the OpenCL API being used.

I don't frequent the forums or use this tool often enough... If anyone sees this and believe it is worth looking into for a bug fix, please direct it to the issues section at github.

12345678 = 8c4ccc2cac6cec1c
abcd = 8646c626

• 8c4ccc2cac6cec1c = Works (8 Chars)
  
• 8c4ccc2cac6cec1c00 = Works (9 Chars)
  
• 8c4ccc2cac6cec1c0086 = Works (10 Chars)
  
• 8c4ccc2cac6cec1c008646 = Fails (11 Chars)
  
• 8c4ccc2cac6cec1c8646c6 = Works (11 Chars; Removed 00)
  
• 8c4ccc2cac6cec1c008646c6 = Fails (12 Chars)
  
• 8c4ccc2cac6cec1c8646c626 = Works (12 Chars; Removed 00)
  
• 8c4ccc2cac6cec1c008646c626 = Fails (13 Chars; Also tried moving the 00 to beginning or end)
  

Switching the CPU (-D 1 in my case) ; it works (Example tested: charset 8c4ccc2cac6cec1c008646 - 11 chars including with 00).

Code:

>type nums.chars
0c8c4ccc2cac6cec1c9c

\Downloads\hashcat-6.1.1>hashcat.exe -a 3 -m 14000 -1 nums.chars --hex-charset 248d3290ce533f02:a5d62a6cd58f41ab ?1?1?1?1?1?1?1?1
hashcat (v6.1.1) starting...

OpenCL API (OpenCL 1.2 ) - Platform #1 [Intel(R) Corporation]
=============================================================
* Device #1: Intel(R) Core(TM) i5-3380M CPU @ 2.90GHz, skipped
* Device #2: Intel(R) HD Graphics 4000, 1361/1425 MB (356 MB allocatable), 16MCU

...[Snip]...

248d3290ce533f02:a5d62a6cd58f41ab:$HEX[8c4ccc2cac6cec1c]

Session..........: hashcat
Status...........: Cracked
Hash.Name........: DES (PT = $salt, key = $pass)
Hash.Target......: 248d3290ce533f02:a5d62a6cd58f41ab
[color=#000000][size=small][font=Monaco, Consolas, Courier, monospace]...[Snip]...[/font][/size][/color]
Guess.Mask.......: ?1?1?1?1?1?1?1?1 [8]
Guess.Charset....: -1 nums.chars, -2 Undefined, -3 Undefined, -4 Undefined
Guess.Queue......: 1/1 (100.00%)
Speed.#2.........:  8258.9 kH/s (12.18ms) @ Accel:1 Loops:1024 Thr:8 Vec:1
Recovered........: 1/1 (100.00%) Digests
Progress.........: 19200000/100000000 (19.20%)