[CentOS] Low random entropy

Sun May 28 23:34:13 UTC 2017
Leon Fauster <leonfauster at googlemail.com>

> Am 29.05.2017 um 00:57 schrieb Rob Kampen <rkampen at kampensonline.com>:
> On 28/05/17 23:56, Leon Fauster wrote:
>>> Am 28.05.2017 um 12:16 schrieb Robert Moskowitz <rgm at htt-consult.com>:
>>> On 05/28/2017 04:24 AM, Tony Mountifield wrote:
>>>> In article <792718e8-f403-1dea-367d-977b157af82c at htt-consult.com>,
>>>> Robert Moskowitz <rgm at htt-consult.com> wrote:
>>>> Interesting. I just did a quick check of the various servers I support,
>>>> and have noticed that all the CentOS 5 and 6 systems report entropy in
>>>> the low hundreds of bits, but all the CentOS 4 systems and the one old
>>>> FC3 system all report over 3000 bits.
>>>> Since they were all pretty much stock installs, what difference between
>>>> the versions might explain what I observed?
>>> This is partly why so many certs found in the U of Mich study are weak and factorable.  So many systems have inadequate entropy for the generation of key pairs to use in TLS certs.  Worst are certs created in firstboot process where at times there is no entropy, but the firstboot still creates its certs.
>> /var/lib/random-seed and $HOME/.rnd are approaches to mitigate this scenario.
> so there are mitigations - the question really is: why hasn't redhat made these mitigations the default for
> their enterprise products - maybe other influences we are unaware of - seems like a huge big hole. With the
> advent of SSL/TLS being mandated by google et al, every device needs access to entropy.

Who said upstream hasn't done something? :-) The mentioned artifacts are the evidence that they are "in place/in use" 
by default. BTW, any crypto-sensitive task needs beside entropy also others prerequisites. So, i recommend checking 
the own systems to understand, what upstream respectively the crypto functions/libraries etc. actually does/do.