Re: [Monotone-devel] non_blocking_rng_ok hook no longer used

[Jack Lloyd]

On Fri, Feb 17, 2006 at 09:58:21AM +0100, Richard Levitte - VMS Whacker wrote:
> In message <address@hidden> on Thu, 16 Feb 2006 21:30:13 -0500, Jack Lloyd 
> <address@hidden> said:
> 
> lloyd>    Botan::Config::set("rng/es_files",
> lloyd>                       (hook_non_blocking_rng_ok() ?
> lloyd>                          "/dev/urandom" : "/dev/random"));
> 
> The problem with that kind of setup is that it's not portable.  I
> haven't looked at the Botan source, but it would surprise me if it
> doesn't already do the very it can to get us as good entropy as
> possible in the different platforms it runs on.  There's no real
> reason we should try to duplicate that work.

Well, maybe not the very best, but as best as I could manage at least. (And
yes, there are many potential entropy sources Botan uses which this simple
(/dev/random|/dev/urandom) hook doesn't really address, of course...) I suppose
'ideally' a user could specify exactly which entropy sources they wanted,
either by naming them specifically or giving desired characteristics (blocking
or not, talks to other processes or not, etc) but I can't imagine there are
many people who would know, want to know, or might possibly care about having
that level of control (probably another argument for dropping the hook
entirely, I guess...)

Oh I should probably point out that the above code would not disable any of the
other entropy sources, it just changes the behavior of reading entropy sources
which provide a file interface from the default 'try /dev/urandom and then
/dev/random if you can't get urandom' to trying just one of them and then
moving on to the other methods.

-J