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Update docs/limits.txt to v6.2.2 limits

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Jens Steube 2021-06-22 16:26:19 +02:00
parent 90f0e78b5b
commit 6e8e44987d
1 changed files with 15 additions and 17 deletions
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docs/limits.txt
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@ -26,16 +26,14 @@ It only means the filename itself.
## Hashing algorithms that internally use UTF-16 characters could in special cases lead to false negatives ## Hashing algorithms that internally use UTF-16 characters could in special cases lead to false negatives
## ##
For optimized kernels only (-O): Since hashcat v6.2.1 there's true UTF16 support for pure kernels: This applies to optimized kernels (-O) only:
The UTF-16 conversion implementation used within the kernel code is very elementary and for performance The UTF-16 conversion implementation used within the kernel code is optimized for performance. For that
reasons does not respect all complicated encoding rules required to correctly convert, for instance, ASCII reason, hashcat does not respect all complicated encoding rules required to correctly convert, for instance,
or UTF-8 to UTF-16LE (or UTF-16BE). ASCII or UTF-8 to UTF-16LE (or UTF-16BE). The implementation most likely fails with multi-byte characters,
because we basically add a zero byte every second byte within the kernel conversion code.
The implementation most likely fails with multi-byte characters, because we basically add a zero byte every Since hashcat v6.2.1 there is true UTF-16 support for pure kernels. UTF-16 is fully supported.
second byte within the kernel conversion code.
Since hashcat v6.2.1 there's true UTF16 support for pure kernels.
## ##
## The use of --keep-guessing eventually skips reporting duplicate passwords ## The use of --keep-guessing eventually skips reporting duplicate passwords
@ -47,23 +45,23 @@ Only if you hit the same password twice for the same hash the password may be sh
If --keep-guessing is not used, this can not occur. If --keep-guessing is not used, this can not occur.
This limitation cannot be fixed, because it would require too much device (GPU/CPU) memory. This limitation cannot be fixed, because it would require too much device (GPU/CPU) memory. If we wanted
to report back all possible password candidates executed in a single kernel invocation, it would require
this much memory per device:
If we wanted to report back all possible password candidates executed in a single kernel invocation, it would require this much memory: Number-of-MCU * Max-threads * Max-accel * Max-inner-loops * sizeof (plain_t)
Number-of-MCU * Max-threads-per-device * Max-accel * Max-inner-loops * sizeof (plain_t) For example, on a Vega64: 64 * 1024 * 1024 * 1024 * 20 = 1,374,389,534,720 bytes = 1280 GB VRAM
For example, on a Vega64: 64 * 512 * 1024 * 1024 * 20 = 687,194,767,360 bytes
## ##
## Hashcat GPU memory usage may be limited by maximum allocation sizes of OpenCL drivers ## Hashcat GPU memory usage may be limited by maximum memory allocation sizes of OpenCL drivers
## ##
Most hashcat hash modes only use a single OpenCL allocation. Most hashcat memory allocations are supposed to remain inside the same memory area.
The size of this allocation is limited by GPU drivers / OpenCL runtimes. The maximum size of a memory allocation is limited by GPU drivers / OpenCL runtimes.
Only a few modes (like scrypt) make more than one allocation. Only a few modes (like scrypt) have special workarounds to make use of more than one allocation.
## ##
## The maximum number of functions per rule is limited to 31 ## The maximum number of functions per rule is limited to 31