On Wed, 8 Nov 2017, Eric Biggers wrote:
On Wed, Nov 08, 2017 at 08:17:12PM +0000, David Howells wrote:
Eric Biggers <ebiggers3@xxxxxxxxx> wrote:
This probably should be grouped with my series "crypto: dh - input validation
fixes", as this is also a fix for Diffie-Hellman. I was actually expecting
Herbert Xu to take these patches, as Diffie-Hellman is now part of the crypto
API (crypto/dh.c); none of the patches actually touch security/keys/.
Fine by me.
If you'd like to maintain the Diffie-Hellman implementation(s) you should
get yourself added to MAINTAINERS for the relevant files.
It touches the MPI lib, though, so it also potentially affects RSA and stuff,
which is why I introduced it to the kernel originally.
True, mpi_powm() might also be reachable by adding a key of type "asymmetric",
in which case this fix would need to go to older kernels than v4.12. If I have
a chance I'll see if I can find a reproducer.
CONFIG_KEY_DH_OPERATIONS and use of mpi_powm() by KEYCTL_DH_COMPUTE goes
back to v4.7, when the MPI library was called directly. KPP was not
implemented yet.
--
Mat Martineau
Intel OTC
