On Mon, Oct 11, 2021 at 12:02:37PM +0200, Ahmad Fatoum wrote:
The CAAM can be used to protect user-defined data across system reboot:
- When the system is fused and boots into secure state, the master
key is a unique never-disclosed device-specific key
- random key is encrypted by key derived from master key
- data is encrypted using the random key
- encrypted data and its encrypted random key are stored alongside
- This blob can now be safely stored in non-volatile memory
On next power-on:
- blob is loaded into CAAM
- CAAM writes decrypted data either into memory or key register
Add functions to realize encrypting and decrypting into memory alongside
the CAAM driver.
They will be used in a later commit as a source for the trusted key
seal/unseal mechanism.
Reviewed-by: David Gstir <david@sigma-star.at>
Tested-By: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Steffen Trumtrar <redacted>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
What is CAAM? This is missing.
/Jarkko