This change affects three key areas, each improving autotuning:
- Autotune refactoring itself
The main autotune algorithm had become too complex to maintain and has
now been rewritten from scratch. The engine is now closer to the old
v6.0.0 version, using a much more straightforward approach.
Additionally, the backend is now informed when the autotune engine runs
its operations and runs an extra invisible kernel invocation. This
significantly improves runtime accuracy because the same caching
mechanisms which kick in normal cracking sessions now also apply during
autotuning. This leads to more consistent and reliable automatic
workload tuning.
- Benchmarking and '--speed-only' accuracy bugs fixed
Benchmark runtimes had become too short, especially since the default
benchmark mask changed from '?b?b?b?b?b?b?b' to '?a?a?a?a?a?a?a?a'. For
very fast hashes like NTLM, benchmarks often stopped immediately when
base words needed to be regenerated, producing highly inaccurate
results.
This issue also misled users tuning '-n' values, as manually
oversubscribing kernels could mask the problem, creating the impression
that increasing '-n' had a larger impact on performance than it truly
does. While '-n' still has an effect, it’s not as significant. With this
fix, users achieve the same speed without needing to tune '-n' manually.
The bug was fixed by enforcing a minimum benchmark runtime of 4 seconds,
regardless of kernel runtime or kernel type. This ensures more stable
and realistic benchmark results, but typically increasing the benchmark
duration by up to 4 seconds.
- Kernel-Threads set to 32 and plugin configuration cleanup
Some plugin configurations existed solely to work around the old
benchmarking bug and can now be removed. For example,
'OPTS_TYPE_MAXIMUM_THREADS' is no longer required and has been removed
from all plugins, although the parameter itself remains to avoid
breaking custom plugins.
Because increasing threads beyond 32 no longer offers meaningful
performance gains, the default is now capped at 32 (unless overridden
with '-T'). This simplifies GPU memory management. Currently, work-item
counts are indirectly limited by buffer sizes (e.g., 'pws_buf[]'), which
must not exceed 4 GiB (a hard-coded limit). This buffer size depends on
the product of 'kernel-accel', 'kernel-threads', and the device’s
compute units. By reducing the default threads from 1024 to 32, there is
now more space available for base words.
Updated kernel declarations from "KERNEL_FQ void HC_ATTR_SEQ" to "KERNEL_FQ KERNEL_FA void". Please update your custom plugin kernels accordingly.
Added spilling size as a factor in calculating usable memory per device. This is based on undocumented variables and may not be 100% accurate, but it works well in practice.
Added a compiler hint to scrypt-based kernels indicating the guaranteed maximum thread count per kernel invocation.
Removed redundant kernel code 29800, as it is identical to 27700, and updated the plugin.
Refactored inc_hash_scrypt.cl almost completely and improved macro names in inc_hash_scrypt.h. Adapted all existing SCRYPT-based plugins to the new standard. If you have custom SCRYPT based plugins use hash-mode 8900 as reference.
Fixed some compiler warnings in inc_platform.cl.
Cleaned up code paths in inc_vendor.h for finding values for HC_ATTR_SEQ and DECLSPEC.
Removed option --device-as-default-execution-space from nvrtc for hiprtc compatibility. As a result, added __device__ back to DECLSPEC.
Removed option --restrict from nvrtc compile options since we actually alias some buffers.
Added --gpu-max-threads-per-block to hiprtc options.
Added -D MAX_THREADS_PER_BLOCK to OpenCL options (currently unused).
Removed all OPTS_TYPE_MP_MULTI_DISABLE entries for SNMPv3-based plugins.
These plugins consume large amounts of memory and for this reason,limited kernel_accel max to 256. This may still be high, but hashcat will automatically tune down kernel_accel if insufficient memory is detected.
Removed command `rocm-smi --resetprofile --resetclocks --resetfans` from benchmark_deep.pl, since some AMD GPUs become artificially slow for a while after running these commands.
Replaced load_source() with file_to_buffer() from shared.c, which does the exact same operations.
Moved suppress_stderr() and restore_stderr() to shared.c and reused them in both Python bridges and opencl_test_instruction(), where the same type of code existed.
Previously, the bridge loaded user source files as Python modules, which required stripping extensions and could lead to confusing name conflicts.
Now, it loads them as regular Python scripts, which is more intuitive and aligns better with user expectations.
Add hipDeviceProp_t and bindings for hipGetDeviceProperties(), hipGetDeviceProperties is required to retrieve gcnArchName[].
Add gcnArchName[] to select the correct --gpu-architecture value for a specific device when using hiprtc.
Include sm_major and sm_minor for CUDA and gcnArchName for HIP in the kernel filename hash.
Update nvrtc_options[] and hiprtc_options[] to avoid unused variables, eliminating the use of --restrict as a placeholder and preventing nvrtc from aborting.
Add check_file_suffix() and remove_file_suffix() helper functions.
Add MAX_THREADS_PER_BLOCK macro to CUDA kernels. It defaults to 1024 or a lower value if limited by the plugin module or specified via the -T command line option.
For CUDA, lower the C++ dialect from C++17 to C++14 to reduce JIT compile time. Also add support for --split-compile and --minimal flags to further improve NVRTC compile performance.
Remove power-hungry NVIDIA settings and fix missing sudo calls in tools/benchmark_deep.pl.
Remove NEW_SIMD_CODE macro from kernels that do not support SIMD (no u32x).
The workaround using EXTRA_SIZE should no longer be needed, so we disable it for now and monitor for any issues with memory allocation.
Fixed a bug where a scrypt-based algorithm on an API would require only a single work item, resulting in size_extra_buffer4 being zero, which fails on OpenCL since it does not allow zero-byte allocations.
Ignore TMTO increase on low scrypt configurations if the R value is higher than 1.
The original sort_by_src_len() function returned 0 even when a > b,
violating the C standard requirements for qsort() comparison functions.
Specifically, it broke antisymmetry and transitivity, which can result
in undefined behavior.
In some versions of glibc, this leads not only to incorrect sorting but
also potential memory corruption[1].
Fix the issue by returning -1 when a > b, restoring compliance with the
standard.
Link: https://www.qualys.com/2024/01/30/qsort.txt [1]
Fixes: 8eb2558a7 ("Add -m 6211 module and moved some code around")
The original sort_pot_orig_line() function returned 0 even when a < b,
violating the C standard requirements for qsort() comparison functions.
Specifically, it broke antisymmetry and transitivity, which can result
in undefined behavior.
In some versions of glibc, this leads not only to incorrect sorting but
also potential memory corruption[1].
Fix the issue by returning -1 when a < b, restoring compliance with the
standard.
Link: https://www.qualys.com/2024/01/30/qsort.txt [1]
Fixes: 6adc217ba ("Keep output of --show and --left in the original ordering of the input hash file")
Do not adjust kernel-accel or scrypt-tmto for GPUs with unified memory, typically integrated GPUs in CPUs (APUs).
Redesign the "4-buffer" strategy to avoid overallocation from naive division by four, which can significantly increase memory usage for high scrypt configurations (e.g., 256k:8:1).
Update the scrypt B[] access pattern to match the new "4-buffer" design.
Allow user-specified kernel-accel and scrypt-tmto values, individually or both, via command line and tuning database. Any unspecified parameters are adjusted automatically.
Permit user-defined combinations of scrypt-tmto and kernel-accel even if they may exceed available memory.
Add support for lower iteration counts per kernel invocation than the default, enabling TMTO for low scrypt configurations, such as N=1024
Use TMTO 2 if it reaches 4 times the device processor count, instead of TMTO 1 always
Improve performance for low scrypt configurations (hash-mode 9300)
Fix unit test for 15700 with correct scrypt configurations
Disable CPU over subscription for SCRYPT based algorithms
Remove hard-coded SCRYPT N, R, and P values in modules, except where they are intentionally hardcoded.
Fix a bug that always caused a TMTO value of 1, even when it was not needed.
Respect device_available_mem and device_maxmem_alloc values even if a reliable low-level free memory API is present, and always select the lowest of all available limits.
Fix benchmark_deep.pl mask to avoid UTF-8 rejects.
Improve error messages when the check verifying that all SCRYPT configuration settings across all hashes are identical is triggered.
Also improve the error message shown when the SCRYPT configuration of the self-test hash does not match that of the target hash.
Fix a bug where a low-tuned SCRYPT hash combined with a TMTO could result in fewer than 1024 iterations, which breaks the hard-coded minimum of 1024 iterations in the SCRYPT kernel.
Prefix device name in tuning-db with device ID to avoid collisions
between identically named devices.
Fix Python bridge Makefile to handle missing python3-config helper.
Alias Devices: Prevents hashcat, when started with x86_64 emulation on Apple Silicon, from showing the Apple M1 OpenCL CPU as an alias for the Apple M1 Metal GPU
