ssh PRNGD socket

[Peter Lachnitt]

Hello,

after update ssh from A.04.40.006 to
A.04.50.003 on hpux 11.11 I get this message if I open a ssh connect:

Couldn't connect to PRNGD socket "/var/run/egd-pool" Connection refused":

But still the ssh works fine. I dont no where the message comes from and where I can switch off this message.

How can I correct this?

Thanks

Peter

[Ralph Grothe]

Does your server have a /dev/random device?
Probably not, but you can check

e.g.

$ ll /dev/{u,}random

or

# ps -fp "$(fuser -u /dev/{u,}random 2>/dev/null)"

On session start a session key must be generated for encryption of the session.
For this arithmetically challenging process a certain degree of entropy is required which processes like the sshd are retreiving either by a pseudo random number generating device like /dev/random (fed from kernel space I assume),
or from a unix domain socket filled by a separate (user space) entropy gathering daemon (egd).
There exists a hp-ux kernel patch I beleive that can supply your system with a /dev/random, but it will require a reboot.
The drawback of the separate egd could be that the initilization time for ssh sessions might take a little longer.

[Ralph Grothe · Accepted solution]

It took a while to find one of our HP hosts that isn't using a /dev/random but resorts to prngd, which must be supplied by some OpenSSL contrib package.
I assume that the HP port of OpenSSH is using this as a fall back if it cannot find a /dev/random.
Do you have a prngd process running at all?

e.g.

$ UNIX95= ps -xC prngd -o user,args
USER COMMAND
root /opt/openssl/prngd/prngd -n -c /opt/openssl/prngd/prngd.conf /var/run/egd-pool

[Peter Lachnitt]

Thanks to all.

I'am install KRNG11I (Strong Random Number Generator) from HP and now ssh works fine without anny messages.

Regards Peter