Nowadays, password wordlist creation usually implies concatenating multiple data sources.

Ideally, most probable passwords should stand at start of the wordlist, so most common passwords are cracked instantly.

With existing dedupe tools you are forced to choose if you prefer to preserve the order OR handle massive wordlists.

Unfortunately, wordlist creation requires both:

So i wrote duplicut in highly optimized C to address this very specific need 🤓 💻

git clone https://github.com/nil0x42/duplicut
cd duplicut/ && make
./duplicut wordlist.txt -o clean-wordlist.txt

• Features:

  • Handle massive wordlists, even those whose size exceeds available RAM
  • Filter lines by max length (-l option)
  • Can remove lines containing non-printable ASCII chars (-p option)
  • Press any key to show program status at runtime.

• Implementation:

  • Written in pure C code, designed to be fast
  • Compressed hashmap items on 64 bit platforms
  • Multithreading support

• Limitations:

  • Any line longer than 255 chars is ignored

An uint64 is enough to index lines in hashmap, by packing size info within pointer's extra bits:

If whole file can't fit in memory, it is split into virtual chunks, in such way that each chunk uses as much RAM as possible.

Each chunk is then loaded into hashmap, deduped, and tested against subsequent chunks.

That way, execution time decreases to at most th triangle number:

If you find a bug, or something doesn't work as expected, please compile duplicut in debug mode and post an issue with attached output:

# debug level can be from 1 to 4
make debug level=1
./duplicut [OPTIONS] 2>&1 | tee /tmp/duplicut-debug.log