Add support for POLYVAL, an ε-Δ-universal hash function similar to
GHASH. This patch only uses POLYVAL as a component to implement HCTR2
mode. It should be noted that POLYVAL was originally specified for use
in AES-GCM-SIV (RFC 8452), but the kernel does not currently support
this mode.
POLYVAL is implemented as an shash algorithm. The implementation is
modified from ghash-generic.c.
For more information on POLYVAL see:
Length-preserving encryption with HCTR2:
https://eprint.iacr.org/2021/1441.pdf
AES-GCM-SIV: Nonce Misuse-Resistant Authenticated Encryption:
https://datatracker.ietf.org/doc/html/rfc8452
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Bug: 233652475
Link: https://lore.kernel.org/linux-arm-kernel/20220520181501.2159644-4-nhuck@google.com/T/
(cherry picked from commit f3c923a09c4c4f5861b1ed53cf75673992a6ba68)
Change-Id: I7a7e177ecddaa103421b3b4e2d2f072e30e0c934
Signed-off-by: Nathan Huckleberry <nhuck@google.com>