Re: [PATCH 2/3] random: rng-seed source is utf-8

Theodore Y. Ts'o
2020-02-14T22:49:00Z

On Fri, Feb 14, 2020 at 01:58:35PM -0600, Rob Herring wrote:
> On Fri, Feb 14, 2020 at 12:10 AM Masami Hiramatsu <mhiramat@kernel.org> wrote:
> >
> > From: Mark Salyzyn <salyzyn@android.com>
> >
> > commit 428826f5358c922dc378830a1717b682c0823160
> > ("fdt: add support for rng-seed") makes the assumption that the data
> > in rng-seed is binary, when it is typically constructed of utf-8
>
> Typically? Why is that?
>
> > characters which has a bitness of roughly 6 to give appropriate
> > credit due for the entropy.

This is why I really think what gets specified via the boot command
line, or bootconfig, should specify the bits of entropy and the
entropy seed *separately*, so it can be specified explicitly, instead
of assuming that *everyone knows* that rng-seed is either (a) a binary
string, or (b) utf-8, or (c) a hex string. The fact is, everyone does
*not* know, or everyone will have a different implementation, which
everyone will say is *obviously* the only way to go....

- Ted