alt Hacker NewsIf there is one way enforcement (i.e. there is one point where the last SHA1 commit was signed by first SHA256 commit), I think it should be safe ?
The "commit before" might be compromised, but the git commits refer a snapshot of a tree + a list of previous commit IDs, so the "new" SHA256 commit will not have any files altered
Every file (indirectly) referred to by a SHA256 commit using a SHA1 hash in some tree object can still be spoofed. Fixing that requires rehashing all objects and recreating all tree objects so the tree objects referred to by SHA256 commits are purely made up of object references computed by SHA256.