revdgst

Collection of various tools to analyze and reverse engineer checksums in short data packets.

Mainly intended to help analyze software defined radio (SDR) data transmission from sensor modules.

Building / Installation

The main tools are written in portable C (C11 standard) and known to compile on Linux, MacOS, and Windows systems.

mkdir build
cd build
cmake ..
make

Work in progress

Currently missing proper options, error checking, and documentation. If this is somewhat useful to you, let me know, I might develop this further.

Inputs

Input files need to contain hex messages. A hex prefix ( 0x ) will be ignored. All padding characters will be ignored. All codes need to be the same length (bytes or nibbles). Inline-comments ( ;, #, // ) will end the line. Multi-line comments ( /* .. */) will be skipped.

If no file is given stdin will be read.

keylst

List keys from LFSR generators.

bitbrk

Analyze and break out bit changes and compare checksums.

revdgst

Reverse 8-bit LFSR digest.

Includes Galois, Fibonacci, Reverse-Galois, Reverse-Fibonacci, Fletcher, Reverse-Fletcher, Shift16. Each on plain data, byte-reflect, bit-reflect, bit-reflect and byte-reflect.

revdgst16

Reverse 16-bit LFSR digest.

revsum

Reverse simple checksums.

Includes byte-wide sums, nibble-wide sum, parity, and CRC-8.

Copyright and Licence

Copyright (C) 2019 Christian W. Zuckschwerdt zany@triq.net

Unless otherwise noted all sources are:

License: GPL-2+