Generate pseudo-random passwords with OpenSSL

27 November 2015
/ GNU Linux
/ By Jan Reilink

OpenSSL comes in handy when you need to generate random passwords, for example for system accounts and services. In this short post I’ll give you a quick example on how to generate random passwords with OpenSSL in Linux (Bash), Windows and PHP…

Pseudo-random passwords and strings with OpenSSL

The OpenSSL rand command can be used to create random passwords for system accounts, services or online accounts. The rand command outputs num pseudo-random bytes after seeding the random number generator once.

You only have to decide the byte-length of your password or string, and OpenSSL does all the calculations.

For example an 8 byte pseudo-random string, hex encoded output:

$ openssl rand -hex 8
28dbc04b1a90fbf4

Or an 8 byte random string, base64 encoded output:

$ openssl rand -base64 8
7UON8PQIYHg=

OpenSSL on Windows

Generate random passwords in Windows using OpenSSL

If you have installed OpenSSL on Windows, you can use the same openssl command on Windows to generate a pseudo-random password or string:

c:\Users\Jan>C:\OpenSSL-Win64\bin\openssl.exe rand -hex 8
33247ca41c60ac53

PHP OpenSSL – create a pseudo-random password with PHP and OpenSSL

In PHP you can use openssl_random_pseudo_bytes(), with bin2hex() for readability:

<?php
  var_dump( bin2hex( openssl_random_pseudo_bytes( 8, $cstrong ) ) );
?>

Yes, hexadecimal strings are all lower-case… All you need now is a way to remember these generated strings and passwords… 😉

This may interest you: How to restore a deleted Open-Xchange context?

Bonus: Use PowerShell to create a random password:

 1..14 | ForEach { $my_passwd = $my_passwd + [char](New-Object System.Random( (get-date).Millisecond + $_ )).next(65,127) }

About the Author Jan Reilink

My name is Jan. I am not a hacker, coder, developer, programmer or guru. I am merely a system administrator, doing my daily thing at Vevida in the Netherlands. With over 15 years of experience, my specialties include Windows Server, IIS, Linux (CentOS, Debian), security, PHP, WordPress, websites & optimization. Want to support me and donate? Use this link: https://paypal.me/jreilink.

follow me on:

Thank you!

06 Aug, 2017

Release hold queue email in Postfix – postsuper

04 Feb, 2016

Recursive scp and symlinks

29 Dec, 2015

Install Varnish Cache on CentOS 6.7

29 Dec, 2015

Install Elasticsearch on CentOS 6.7

25 Mar, 2015

Turn off swap