libquickxor is the C implementation of the QuickXorHash.
The QuickXorHash is the digest used by Microsoft on Office 365 OneDrive for Business and Sharepoint. It was published by Microsoft in 2016 in form of a C# script. The explanation describes it as a "quick, simple non-cryptographic hash algorithm that works by XORing the bytes in a circular-shifting fashion".
The project is built with Pelles C v12. Many thanks to the author for his C code :
https://github.com/Tekki/quickxor-c