Detecting attempted collisions with sha1dc

Posted Mar 2, 2017 10:06 UTC (Thu) by jnareb (subscriber, #46500)
Parent article: Moving Git past SHA-1

With the version currently in 'pu' (proposed updates) branch, Git can be configured with the USE_SHA1DC build time configuration variable to use SHA-1 implementation from shattered.io that detects attempted collisions[1]. Note that for the time being it is quite a bit slower than other implementations; optimization is ongoing.

This way with `transfer.fsckObjects` any attempt can be easily detected.

[1]: https://github.com/cr-marcstevens/sha1collisiondetection