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

Mark Salyzyn
2020-02-14T22:55:40Z

On 2/14/20 2:47 PM, Theodore Y. Ts'o wrote:
> 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

Given that the valid option are between 4 (hex), 6 (utf-8) or 8
(binary), we can either split the difference and accept 6; or take a
pass at the values and determine which of the set they belong to
[0-9a-fA-F], [!-~] or [\000-\377]  nor need to separately specify.

-- Mark