hashcat @6.2.5_0: "No devices found/left" message on Apple M1 Max chip

[JDLH (Jim DeLaHunt)]

hashcat is a tool designed to run on GPUs, not CPUs. It has a range of code to detect available GPUs. It appears to be unable to use the GPU of the Apple M1 Max chip on my mac.

To reproduce: Perform any crack attempt, e.g. the one described in their ​example0.sh:

% hashcat -m 0 -t 32 -a 7 /opt/local/share/doc/hashcat/example0.hash '?a?a?a?a' /opt/local/share/doc/hashcat/example.dict 

Observed behaviour:

% hashcat -m 0 -t 32 -a 7 /opt/local/share/doc/hashcat/example0.hash '?a?a?a?a' /opt/local/share/doc/hashcat/example.dict 
hashcat (v6.2.5) starting

No devices found/left.

Started: Sun Oct 15 18:21:43 2023
Stopped: Sun Oct 15 18:21:43 2023

The message "No devices found/left" seems to say that hashcat was unable to find the M1 Max GPU, so gave up.

Expected behaviour: No error message, "No devices found/left".

Hashcat successfully cracks the example password.

Discussion:

My Mac is a MacBookPro18,2, with an Apple M1 Max chip having 10 cores (8 performance and 2 efficiency). This is what Hashcat detects for my GPUs:

% hashcat -I             
hashcat (v6.2.5) starting in backend information mode

OpenCL Info:
============

OpenCL Platform ID #1
  Vendor..: Apple
  Name....: Apple
  Version.: OpenCL 1.2 (Aug 17 2023 05:46:52)

  Backend Device ID #1
    Type...........: GPU
    Vendor.ID......: 2
    Vendor.........: Apple
    Name...........: Apple M1 Max
    Version........: OpenCL 1.2 
    Processor(s)...: 32
    Clock..........: 1000
    Memory.Total...: 49152 MB (limited to 4608 MB allocatable in one block)
    Memory.Free....: 24512 MB
    OpenCL.Version.: OpenCL C 1.2 
    Driver.Version.: 1.2 1.0

The -D 2 option apparently forces hashcat to choose a GPU over a CPU to use for its work. When I include that option, I get a runtime error:

% hashcat -D 2 -m 0 -t 32 -a 7 /opt/local/share/doc/hashcat/example0.hash '?a?a?a?a' /opt/local/share/doc/hashcat/example.dict
hashcat (v6.2.5) starting

* Device #1: Apple's OpenCL drivers (GPU) are known to be unreliable.
             You have been warned.

OpenCL API (OpenCL 1.2 (Aug 17 2023 05:46:52)) - Platform #1 [Apple]
====================================================================
* Device #1: Apple M1 Max, 24512/49152 MB (4608 MB allocatable), 32MCU

Minimum password length supported by kernel: 0
Maximum password length supported by kernel: 256

Dictionary cache built:
* Filename..: /opt/local/share/doc/hashcat/example.dict
* Passwords.: 128416
* Bytes.....: 1069601
* Keyspace..: 128416
* Runtime...: 0 secs

Hashes: 6494 digests; 6494 unique digests, 1 unique salts
Bitmaps: 16 bits, 65536 entries, 0x0000ffff mask, 262144 bytes, 5/13 rotates

Optimizers applied:
* Zero-Byte
* Early-Skip
* Not-Salted
* Not-Iterated
* Single-Salt
* Raw-Hash

ATTENTION! Pure (unoptimized) backend kernels selected.
Pure kernels can crack longer passwords, but drastically reduce performance.
If you want to switch to optimized kernels, append -O to your commandline.
See the above message to find out about the exact limits.

Watchdog: Hardware monitoring interface not found on your system.
Watchdog: Temperature abort trigger disabled.

Initializing backend runtime for device #1. Please be patient...UNSUPPORTED (log once): buildComputeProgram: cl2Metal failed
clBuildProgram(): CL_BUILD_PROGRAM_FAILURE

Compilation failed: 

program_source:7:10: fatal error: 'inc_vendor.h' file not found
#include "inc_vendor.h"
         ^~~~~~~~~~~~~~

* Device #1: Kernel /opt/local/share/hashcat/OpenCL/shared.cl build failed.

Started: Sun Oct 15 18:30:21 2023
Stopped: Sun Oct 15 18:30:25 2023

Adding the -O option does not change the end result: failure, with the same message.

The [​​https://hashcat.net/wiki/doku.php?id=frequently_asked_questions#installation Hashcat project's installation FAQ] mentions Windows and Linux, but not macOS. It mentions OpenCL, AMD, and nVidia, but not Apple or Apple's ​Metal framework. Their ​Supported GPUs FAQ similarly does not mention Apple or Apple Silicon or M1. It is interesting that the error message does mention "metal", however.