[cryptolib] entropy driver

[moidx]

The Entropy driver aims to provide the following services:

• Interface to software csrng instance #14372
• Interface to pre-conditioned entropy provided by the entropy_src
• csrng KAT interface.
• entropy_src pre-conditioner (SHA3-384) KAT interface.
• [cryptolib] continuous mode config incl. health checks for entropy_src #14364
• edn0 and edn1 helper routines to configure entropy for countermeasures and FIPS entropy source for otbn.
• Health checks and error handling.
• Health test configuration hardening (entropy_src), as those registers are not shadowed.

From a FIPS perspective, KAT tests will be required for algorithms within scope of potential certifications. It may be possible to implement such tests at a higher level of abstraction, but planning to add them along with the driver as optional libraries to drive basic functional test cases.

[tjaychen]

@moidx at one point we talked about needing additional software checks for some of the register healthtest configurations (since they are not shadowed). Should that be part of this issue also? Or not since it's not an explicit service?

[moidx]

Hi @tjaychen, yes, let me add it to the list. We are planning to use this driver as part of the cryptolib, which will cover ROM_EXT, manufacturing and other use cases.

Marking as M2 since I am planning to implement some system level tests with this driver.

[tjaychen]

thanks @moidx