How do I generate random bytes with
Another command in
rand. We invoke it like this:
$ openssl rand -hex 10 aa27660aa7e186902981
10 indicates the number of random bytes to print to standard out.
-hex prints those bytes in hex format - 2 characters per byte, so 20 characters.
The output comes from a PRNG. The PRNG is seeded with, amongst other randomness sources, a file at
~/.rnd. This file contains random bytes:
$ cat ~/.rnd 33k�ɱ��%�*��#Yn�� ]w$Lkn���M|cW@9%V ...
OpenSSL apparently uses this location to store previously-gathered entropy. You can delete it at any time without any ill effects.
More by Jim
- Your syntax highlighter is wrong
- Granddad died today
- The Three Ts of Time, Thought and Typing: measuring cost on the web
- I hate telephones
- The sorry state of OpenSSL usability
- The dots do matter: how to scam a Gmail user
- My parents are Flat-Earthers
- How Hacker News stays interesting
- Project C-43: the lost origins of asymmetric crypto
- The hacker hype cycle
- The inception bar: a new phishing method
- Time is running out to catch COVID-19
- A probabilistic pub quiz for nerds
- Smear phishing: a new Android vulnerability
Tagged . All content copyright James Fisher 2017. This post is not associated with my employer. Found an error? Edit this page.