Eric Biggers <ebiggers3@xxxxxxxxx> wrote: > > > By the way: do we really need this in the kernel at all, given that it's > > > just doing some math on data which userspace has access to? > > > > It is the question about how we want the keys subsystem to operate. The DH > > shared secret shall not be used as a key. But the DH operation is part of > > the key subsystem. If there is never a case where the result of the DH > > operation is used in the kernel, then the KDF can be removed and my > > patches could be reverted. However, in this case, the entire DH business > > could be questioned as this can easily be done in user space as well. > > > > Well, who exactly is asking for Diffie-Hellman in the kernel at all? If it > can be done in userspace then it should be done there. Having it in the > kernel means having yet another API that's callable by unprivileged users > and needs to be audited for security vulnerabilities. Just because the > kernel can support doing hashes or has an arbitrary-precision arithmetic > library or whatever doesn't mean it's the right place to do random crypto > stuff. I understood that there is the possibility of offloading this to hardware. David
