Questions tagged [random-number-generator]

A Random Number Generator is a device or program that generates (pseudo)random numbers for use in cryptography. Examples are the Unix devices `/dev/random` and `/dev/urandom`

Filter by
Sorted by
Tagged with
-1
votes
1answer
23 views

AWS Linux Source Code?

We are looking for the source code for Amazon Web Services (AWS) AWS Linux kernel. This should be available under the GPL, but we can't find it, and our requests to Amazon have gone unanswered. ...
2
votes
1answer
37 views

Why can't I manually seed the FreeBSD random number generator?

Years ago, I could manually seed the random number generator in FreeBSD by setting: sysctl -w kern.random.sys.seeded=0 ... and then if I deleted my SSH keys (on purpose) and restarted sshd, I would ...
1
vote
0answers
930 views

Apache and htpasswd getting errors from random number generator

Recently (probably after yum update something), one of my CentOS7 server running Apache2.4.37 has started to produce the following errors. apachectl configtest (38)Function not implemented: AH00141: ...
-3
votes
1answer
144 views

What does the hexdump of the first 16 bytes of /dev/random mean? [closed]

What does the hex dump of the first 16 bytes of /dev/random mean? When I run head -c 16 /dev/random I get the following results: 0000000 fd43 2676 f87d 8f78 00c9 3119 f697 100c 0000010 What do ...
2
votes
1answer
654 views

How EJBCA generate private key

I'm looking for the method used by EJBCA to generate the private keys in general (CA, Sub-Ca, certificates...). Let say for instance you want RSA 2048 key size. Is the generation process all done in ...
7
votes
2answers
307 views

LUKS Error During Boot

alg: drbg: could not allocate DRNG handle for ... I only see this error on the console during the boot process of virtual machines we create. EDIT: 2/5/16 - I see it on some bare-metal installations, ...
-2
votes
1answer
1k views

Create random file with openssl [closed]

So I read this questionUrandom Alternative, but I am unable to make a comment there (without 50 rep) - therefore I open a separate question: If I use this command instead of dd and urandom, how do I ...
-2
votes
1answer
77 views

How to verify whether randomness was written to a device and what exactly has been written?

I am preparing a device with shred to use it later on encrypted with dm-crypt/cryptsetup/luks. How can I check the device before and after using shred or e.g openssl/dd with /dev/urandom to be sure ...
1
vote
2answers
825 views

How many bits of entropy per byte read from /dev/random and /dev/urandom?

Approximately how many bits of entropy are contained in each byte read from /dev/random and /dev/urandom? Data from /dev/random uses the kernel random-number generator while /dev/urandom uses a CPRNG ...
0
votes
1answer
739 views

Run 'rng-tools' in OpenVZ container

I have a problem with run 'rngd' inside OpenVZ container: root@server:~# rngd -r /dev/urandom unable to adjust write_wakeup_threshold: Permission denied Is it possible to run an application in ...
0
votes
1answer
60 views

Hosting a /dev/random dependent service

I have developed a game that requires shuffled decks of cards to run. Since it uses /dev/random to generate shuffled decks, I was wondering what sort of concerns should I take into account before ...
1
vote
1answer
679 views

Is the shred utility always safe given a good random number generator?

I recently experimented with different methods of disk randomization to find what would get the job done fastest. The openssl random number generator with AES in counter mode was said to be pretty ...
7
votes
2answers
4k views

Is there a way to monitor /dev/random?

We're investigating some JDBC issues, and one of the possible problems is /dev/random being exhausted. The workaround is to switch the JVM to using /dev/urandom, but I wan't to try and determine ...
0
votes
1answer
2k views

Is it possible to pass /dev/urandom through from the host to a qemu/kvm guest?

I'd like to pass the host's /dev/urandom device through to a qemu/kvm virtual machine. Note that /dev/urandom is not seekable, so it's not possible to pass it through as a block device using -hda, -...
3
votes
1answer
5k views

Nginx (openresty) generating random numbers

I have openresty set up on a server (nginx bundle which includes the lua module) and I'm trying to create a script which has specific odds of setting a cookie on a user's browser. My code looks like ...
1
vote
1answer
1k views

modprobe amd-rng fails, No such device

When trying to install hw_random to a 2.6 kernel, modprobe returns a FATAL error "No such device" on both CentOS 5.7 and Fedora 15. Both are using the latest kernel, respectively. The .ko file exists,...
19
votes
6answers
17k views

How do I get /dev/random to work on an Ubuntu virtual machine?

Apparently, /dev/random is based on hardware interrupts or similar unpredictable aspects of physical hardware. Since virtual machines don't have physical hardware, running cat /dev/random within a ...
50
votes
6answers
64k views

How to read in N random characters from /dev/urandom?

read /dev/urandom 3 The above is not working..How can I read random bytes from /dev/urandom in bash?
2
votes
3answers
1k views

Feeding the kernels entropy source from other machines and/or increasing its maximum size

We have has a little trouble with a small box that acts as a VPN end-point and mail relay for our network, caused by the available entropy for /dev/random being too low (which causes TLS connection ...
3
votes
3answers
1k views

Munin “Available entropy” when using address space layout randomization

Having just configured Munin for statistics logging on my gentoo server (hardened profile), I am noticing that my "Available entropy" is consitently in the 200-300 range. This seems way to low, so I ...
4
votes
9answers
613 views

Random Number Generation [closed]

I have a need for true random number generation. I've been looking at a number of hardware solutions. Does anybody have any solid experiences with these? Any recommendations? I don't think I can make ...