quickxorhash is a C library (libqxh) implementing Microsoft's QuickXORHash algorithm. It also includes a small command-line utility that calculates and displays the hash of a file.
QuickXORHash is a non-cryptographic hash function that XORs the input bytes in a circular shift pattern, then XORs the least significant bits of the hash with the input length. The canonical representation of the resulting hash is a Base64 encoded string, because hexadecimal is too plebeian.
- OpenSSL or a compatible implementation of libcrypto.
The only known usage of this hash is in OneDrive for Business; consumer OneDrive uses SHA-1 and CRC32 for fingerprinting.