tree 2a6c10fcb99ecb99da8b1bc30f38999833452a69
parent a2fb864c042b00debc7696d4459d8058ec7c8013
author Horia Geantă <horia.geanta@nxp.com> 1564578491 +0300
committer Herbert Xu <herbert@gondor.apana.org.au> 1565327509 +1000

crypto: caam - fix MDHA key derivation for certain user key lengths

Fuzz testing uncovered an issue when |user key| > |derived key|.
Derived key generation has to be fixed in two cases:

1. Era >= 6 (DKP is available)
DKP cannot be used with immediate input key if |user key| > |derived key|,
since the resulting descriptor (after DKP execution) would be invalid -
having a few bytes from user key left in descriptor buffer
as incorrect opcodes.

Fix DKP usage both in standalone hmac and in authenc algorithms.
For authenc the logic is simplified, by always storing both virtual
and dma key addresses.

2. Era < 6
The same case (|user key| > |derived key|) fails when DKP
is not available.
Make sure gen_split_key() dma maps max(|user key|, |derived key|),
since this is an in-place (bidirectional) operation.

Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Reviewed-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>