Re: [kernel-hardening] Re: [PATCH v4 13/13] random: warn when kernel uses unseeded randomness

On Sun, Jun 18, 2017 at 7:55 PM, Stephan Müller [off-list ref] wrote:

But you bring up an interesting point: if it is true you say that it is hard
for people to use differnent types of APIs regarding entropy and random
numbers right (which I would concur with), and considering that you imply that
get_random_bytes, get_random_u32 and get_random_u64 have the same security
strength, why do we have these three APIs to begin with? The get_random_bytes
API would then be more than enough.

Because there are efficiences we can benefit from for getting integer
sized outputs.

Use get_random_{u32,u64} when you want a secure random number.
Use get_random_bytes when you want a longer secure random bytestring.