crypto: nhpoly1305 - add NHPoly1305 support

Add a generic implementation of NHPoly1305, an ε-almost-∆-universal hash
function used in the Adiantum encryption mode.

CONFIG_NHPOLY1305 is not selectable by itself since there won't be any
real reason to enable it without also enabling Adiantum support.

Signed-off-by: Eric Biggers <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
6 files changed