tree 5ca85e94abb5930ca5f5ecc6fb53e69e50b5da6a
parent d266c68b1cd8c51e10b19a4d54cc0872f7c295c7
author Pirmin Vogel <vogelpi@lowrisc.org> 1595663733 +0200
committer Greg Chadwick <gac@lowrisc.org> 1595853826 +0100

[aes/rtl] Fix status tracking for initial key and IV registers

Whenever the key is used, this must be signaled. When starting decryption,
the key is declared as not new any more to re-trigger decryption key
generation upon future key updates. When performing encryption, the key
is now declared as armed: It is still new and will trigger decryption key
generation, but any future write to a key register will reset the status
tracking (declares the key as dirty) to prevent partial key updates.

Similarly, when the IV has been fully updated internally, any write by
software must reset the status tracking to prevent partial updates by
software.

This resolves lowRISC/OpenTitan#2913.

Signed-off-by: Pirmin Vogel <vogelpi@lowrisc.org>