Computes a hash by using an algorithm based on the XOR-cipher. Basically, it splits the file in chunks whose byte-length is the same as the digest size (padding with 0s), and XORs all those chunks together into a new chunk of the same size, the resulting chunk is printed to stdout.
This isn't a good hash function, it's only good for checksums, because it lacks the Avalanche Effect, flipping 1 input bit flips 1 output bit. It is intended to be a simple/basic, educational, and fast checksum algorithm.
The digest size is 64bit (8Byte) by default, but can be set to any valid usize value with the --length option. The initialization-vector is hardcoded to be 0x0.
Both the naming and behavior are based on cksum, md5sum, and b3sum.
sh
cargo install xorsum
xorsum [OPTION]... [FILE]...
If you want to build from source:
sh
cd [REPO] #path to cloned/downloaded repo
cargo build --release
For info about options, run:
sh
xorsum --help
Let's create an empty text file named a. The output of xorsum --len 4 a should be:
00000000 a
If we write "aaaa" to this file and rehash it with xorsum a -l 4, the output will be:
61616161 a
Because "61" is the hex value of UTF-8 char "a"
Rehashing the file with xorsum a -b yields:
6161616100000000
This is because both the IV and padding are all zeros.
DO NOT USE FOR ðCRYPTOGRAPHIC PURPOSES. The algorithm is not crypto-secure.
DO NOT SHARE HASHES OF PRIVATE DATA. You might be leaking sensitive information. The smaller the file, the more data you leak. The bigger the hash, the more data you leak. Small hashes and bigger files are safer, because the sbox will (probably) have enough bytes to "mix well".
I am not responsible for any misuse of this software