KernelBuilder

Python port of the original C# tool. Auto-generates Hashcat OpenCL kernels and modules from PHP-like hash expressions like (md5(sha1($plain).sha256($salt))).

KernelBuilder takes a simple expression like md5($plain.$salt) or sha1(md5($plain)) and automatically generates a complete Hashcat plugin: pure OpenCL kernels for attack modes -a 0, -a 1, and -a 3, plus the C module for hash parsing and encoding.

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Features

• Auto-generate Hashcat plugins from intuitive PHP-like syntax
• Supported algorithms: MD5, SHA1, SHA224, SHA256
• Nested hashing: md5(sha1($plain)), sha256(md5($salt.$plain)), etc.
• Salt support: $salt and $plain concatenation in any order
• CUT support: Truncate intermediate hashes to a specific byte length
• Attack modes: Generates pure kernels for -a 0 (rules), -a 1 (combinator), and -a 3 (mask/vector)
• Single & Multi hash: Both mXXXXX_sxx and mXXXXX_mxx kernels
• Endianness aware: Automatically handles little-endian (MD5) and big-endian (SHA-family) conversions

Not included in this version: optimized (-O) kernel generation. Run cracking sessions without -O (or with -w in benchmark mode) — the generated plugin only ships -pure.cl kernels.

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Requirements

• Python 3.7+
• Hashcat source code (for compiling the generated plugin)

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Usage

python3 kernel_builder.py <algorithm> <ID> [--overwrite] [--hashcat] [--list] [--hashcat-path PATH]

Argument	Description
algorithm	Hash expression, e.g. 'md5($plain)', 'sha1($plain.$salt)'
ID	Kernel ID / Hashcat -m number (1-5 digits, e.g. 98000)
--overwrite	Overwrite a previously generated plugin folder
--hashcat-path PATH	Path to the Hashcat directory to write into (used with --hashcat). If omitted, you will be prompted for it interactively.
--hashcat	Write directly into a Hashcat source tree's OpenCL/ and src/modules/ folders instead of plugins/<ID>/
-l, --list	List supported algorithms and exit

Examples

python3 kernel_builder.py 'md5($plain)' 98000
python3 kernel_builder.py 'sha1($plain.$salt)' 98001
python3 kernel_builder.py 'sha224($salt.$plain)' 98002
python3 kernel_builder.py 'sha256($salt.$plain)' 98003
python3 kernel_builder.py 'md5(sha1($plain))' 98004 --hashcat
python3 kernel_builder.py 'sha256($salt.CUT16_md5($plain))' 92000 --overwrite

Output layout (without --hashcat)

plugins/<ID>/
├── OpenCL/
│   ├── m<ID>_a0-pure.cl
│   ├── m<ID>_a1-pure.cl
│   └── m<ID>_a3-pure.cl
└── src/modules/
    └── module_<ID>.c

Copy the two subfolders into your Hashcat source tree and rebuild:

cp -r plugins/<ID>/* /path/to/hashcat/

Then compile Hashcat: https://github.com/hashcat/hashcat/blob/master/BUILD.md

Testing

./hashcat -b -m <ID>                                    # benchmark (pure kernel)
./hashcat -a0 -m <ID> hashes.txt wordlist.txt -r rules/best64.rule

Do not pass -O — no optimized kernels are shipped, so Hashcat would fail to find the tiered symbol names (s04/m04 etc.) it looks up under -O.

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Credits

Python port based on the original KernelBuilder by Penguinkeeper.