Messages in this thread | | | Date | Sat, 17 May 2008 13:05:35 -0700 | From | Arjan van de Ven <> | Subject | Re: [PATCH] Re: [PATCH] drivers/net: remove network drivers' last few uses of IRQF_SAMPLE_RANDOM |
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On Sat, 17 May 2008 12:54:02 -0700 "Chris Peterson" <cpeterso@cpeterso.com> wrote:
> Andi, can you please clarify what you mean by "auto-feeding > /dev/urandom only" and "only get blocking /dev/random with the user > daemon"? Are you suggesting that the kernel provides /dev/urandom and > a userspace daemon (e.g. EGD) provides /dev/random? > > Also, if crypto apps like ssh and openssl use on "insecure" > /dev/urandom, then who actually relies on /dev/random?
gpg does for key generation
> For comparison, > FreeBSD does not even (AFAIK) have /dev/urandom. FreeBSD's /dev/random > is nonblocking (like Linux's /dev/urandom) and includes network > entropy. >
I think the big kicker is the difference between a session key (short lived) and a "real" key such as a gpg key that lives for a long time and is used for multile sessions and with different users (in crypto speak, Alice uses the same random key for Bob, Charlotte and David and potentially for a long time). For a session key, urandom is very likely an acceptable compromise; there's only so much data it's used for. For long term keys I can totally see why /dev/random is used instead.
So both have value, just in different circumstances.
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