macOS - mask attack doesn't work
#1
I'm having a problem where wordlist attacks work just how you'd expect, but brute-force / mask attacks never recover any passwords. For example when I run this command:

Code:
hashcat -a 3 3c68f35450c4b594072841cfc1c5785f ?l?l?l?l?l?l?l?l


hashcat will finish within a second not having recovered any hashes. The specified hash is the MD5 result of "thistest".

Code:
Session.Name...: hashcat
Status.........: Exhausted
Input.Mode.....: Mask (?l?l?l?l?l?l?l?l) [8]
Hash.Target....: 3c68f35450c4b594072841cfc1c5785f
Hash.Type......: MD5
Time.Started...: 0 secs
Speed.Dev.#2...:   700.6 GH/s (0.05ms)
Recovered......: 0/1 (0.00%) Digests, 0/1 (0.00%) Salts
Progress.......: 208827064576/208827064576 (100.00%)
Rejected.......: 0/208827064576 (0.00%)

I'm confused by this because it should've recovered my hash, but it didn't. Also the processing rate of 700GH/s sounds absurd. I'm running macOS 10.11.4 and hashcat 3.10.

Any ideas?
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#2
Code:
$ ./hashcat -a 3 3c68f35450c4b594072841cfc1c5785f ?l?l?l?l?l?l?l?l
hashcat () starting...

OpenCL Platform #1: Apple              
=========================
- Device #1: Intel(R) Core(TM) i5-2500S CPU @ 2.70GHz, skipped
- Device #2: ATI Radeon HD 6770M, 128/512 MB allocatable, 6MCU

Hashes: 1 hashes; 1 unique digests, 1 unique salts
Bitmaps: 16 bits, 65536 entries, 0x0000ffff mask, 262144 bytes, 5/13 rotates
Applicable Optimizers:
* Zero-Byte
* Precompute-Init
* Precompute-Merkle-Demgard
* Meet-In-The-Middle
* Early-Skip
* Not-Salted
* Not-Iterated
* Single-Hash
* Single-Salt
* Brute-Force
* Raw-Hash
- Device #2: Kernel m00000_a3.cd8bb6fb.kernel not found in cache! Building may take a while...
- Device #2: Kernel markov_le.cd8bb6fb.kernel not found in cache! Building may take a while...

3c68f35450c4b594072841cfc1c5785f:thistest                
                                                         
Session.Name...: hashcat
Status.........: Cracked
Input.Mode.....: Mask (?l?l?l?l?l?l?l?l) [8]
Hash.Target....: 3c68f35450c4b594072841cfc1c5785f
Hash.Type......: MD5
Time.Started...: 0 secs
Speed.Dev.#2...:   932.7 MH/s (10.77ms)
Recovered......: 1/1 (100.00%) Digests, 1/1 (100.00%) Salts
Progress.......: 410984448/208827064576 (0.20%)
Rejected.......: 0/410984448 (0.00%)
Restore.Point..: 21504/11881376 (0.18%)

Started: Mon Oct 10 11:09:59 2016
Stopped: Mon Oct 10 11:10:05 2016
$

Quote:Any ideas?

Yes, include the rest of the command's output.
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#3
Code:
hashcat (v3.10) starting...

OpenCL Platform #1: Apple               
=========================
- Device #1: Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz, skipped
- Device #2: GeForce GTX 650 Ti, 256/1024 MB allocatable, 4MCU

Hashes: 1 hashes; 1 unique digests, 1 unique salts
Bitmaps: 16 bits, 65536 entries, 0x0000ffff mask, 262144 bytes, 5/13 rotates
Applicable Optimizers:
* Zero-Byte
* Precompute-Init
* Precompute-Merkle-Demgard
* Meet-In-The-Middle
* Early-Skip
* Not-Salted
* Not-Iterated
* Single-Hash
* Single-Salt
* Brute-Force
* Raw-Hash
INFO: approaching final keyspace, workload adjusted       

                                                          
Session.Name...: hashcat
Status.........: Exhausted
Input.Mode.....: Mask (?l?l?l?l?l?l?l?l) [8]
Hash.Target....: 3c68f35450c4b594072841cfc1c5785f
Hash.Type......: MD5
Time.Started...: 0 secs
Speed.Dev.#2...:   610.5 GH/s (0.05ms)
Recovered......: 0/1 (0.00%) Digests, 0/1 (0.00%) Salts
Progress.......: 208827064576/208827064576 (100.00%)
Rejected.......: 0/208827064576 (0.00%)

Started: Mon Oct 10 12:51:51 2016
Stopped: Mon Oct 10 12:51:53 2016
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#4
It's an opencl runtime problem. If possible try to update the driver. Anyway, not hashcats fault here.
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#5
(10-10-2016, 05:14 PM)atom Wrote: It's an opencl runtime problem. If possible try to update the driver. Anyway, not hashcats fault here.

thanks for the feedback. do you have any information you can point me to? the FAQ are pretty much linux and windows only and i cannot find anything in the macOS and OpenCL matter. if i understand correctly its implemented by default and theres no way to update anything...

EDIT: btw on my macbook air hashcat isnt working at all. this might be a different topic but im getting the "clCreateProgramWithBinary(): CL_INVALID_VALUE" -error. this has been happening since i updated to macOS Sierra.
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#6
Apple's OpenCL runtime started out as crap, then it got better and better until Yosemite, at which point it was quite good (all JtR OpenCL formats ran fine on my laptop). Then with El Capitan it got really bad again and with Sierra things aren't much better. Unfortunately there isn't much you can do - we are stuck with whatever version Apple feeds us.

You could submit bug reports to Apple but I have a feeling piping them to /dev/null will be just as effective.
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#7
well at least i got some answers now. thanks for your time!
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