Am Mittwoch, 6. Juni 2018, 14:48:33 CEST schrieb Harald Freudenberger: Hi Harald, > > I am still searching for a way to provide our good hardware entropy > source to the random pool in the random device driver. So I'd like to > have a new arch interface which is called when the random pool finds > out that it is running out of entropy. My feeling is that it should > not be the only source but should still be mixed with other sources > of entropy. It should not be able to dominate or occupy the random > pool but contribute to a significant part. > > As nowadays true random generators provide conditioned data usually > with some kind of hashing algorithm a granularity of 4 or 8 bytes is > waste of random entropy. The s390 TRNG uses SHA512 and can provide > 64 bytes entropy with each invocation. Other TRNGs may use sha1 or > sha256 and so provide 20 or 32 bytes of random. However, the API > could be something like: > > int arch_get_entropy(void *buf, int bufsize); Why not using the add_hwgenerator_randomness with a kernel thread that is controlled/spawned from the noise source? Ciao Stephan
