Re: [Qemu-devel] [PATCH for-4.1 0/7] Add qemu_getrandom and ARMv8.5-RNG

[Daniel P . Berrangé]

On Wed, Mar 13, 2019 at 08:25:45AM -0700, Richard Henderson wrote:
> On 3/12/19 11:41 PM, address@hidden wrote:
> > time make address@hidden SHOW_ENV=1 J=14 NETWORK=1
> > === TEST SCRIPT END ===
> > 
> >   CC      hw/acpi/trace.o
> >   CC      hw/alpha/trace.o
> > /tmp/qemu-test/src/util/random.c: In function 'do_jrand48':
> > /tmp/qemu-test/src/util/random.c:41:15: error: implicit declaration of 
> > function 'jrand48'; did you mean 'do_jrand48'? 
> > [-Werror=implicit-function-declaration]
> >          val = jrand48(xsubi);
> 
> Hmm, no jrand48 in mingw.  I assumed it would be there because of POSIX.
> Perhaps I should just bite the bullet and inline my own DRNG...

We already have an internal API for providing strong random bytes in
QEMU qcrypto_random_bytes. It is preferentially backed by gnutls or
gcrypt, but if those aren't built-in it falls back to a platform
native API like /dev/random. I've got a todo item to make that use
getrandom on Linux/BSD when available.

I don't think we should be adding a new APIs for getting random
numbers that aren't backed by the qcrypto_random_bytes.

By all means add wrappers around qcrypto_random_bytes to make it more
convenient to get random numbers with a given data types (int64, int32
etc) though.


Regards,
Daniel
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