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Generate a random password 30 characters long

Terminal - Generate a random password 30 characters long
gpg --gen-random --armor 1 30
2011-07-20 15:32:49
User: atoponce
Functions: gpg
Generate a random password 30 characters long

According to the gpg(1) manual:

--gen-random 0|1|2 count

Emit count random bytes of the given quality level 0, 1 or 2. If count is not given or zero, an endless sequence of random bytes will be emitted. If used with --armor the output will be base64 encoded. PLEASE, don't use this command unless you know what you are doing; it may remove precious entropy from the system!

If your entropy pool is critical for various operations on your system, then using this command is not recommended to generate a secure password. With that said, regenerating entropy is as simple as:

du -s /

This is a quick way to generate a strong, base64 encoded, secure password of arbitrary length, using your entropy pool (example above shows a 30-character long password).


There are 28 alternatives - vote for the best!

Terminal - Alternatives
strings /dev/urandom | grep -o '[[:alnum:]]' | head -n 30 | tr -d '\n'; echo
2009-02-16 00:39:28
User: jbcurtis
Functions: grep head strings tr

Find random strings within /dev/urandom. Using grep filter to just Alphanumeric characters, and then print the first 30 and remove all the line feeds.

cat /dev/urandom | tr -dc A-Za-z0-9 | head -c 32
pwgen 30 1
2011-07-24 19:43:48
User: sairon

The pwgen program generates passwords which are designed to be easily memorized by humans, while being as secure as possible. Human-memorable passwords are never going to be as secure as completely completely random passwords. [from pwgen man page]

openssl rand -base64 12
2011-07-06 17:48:26
User: Mozai
Tags: password

Another password maker, for human-unfriendly passwords. '-base64' output will make sure it it can be typed on a keyboard, though the output string length will always be a multiple of 4.

strings /dev/urandom | tr -cd '[:alnum:]' | fold -w 30 | head -n 1
2014-12-11 06:21:51
User: atoponce
Functions: fold head strings tr

This command is similar to the alternate, except with head(1), you can pick as many passwords as you wish to generate by changing the number of lines you wish to preview.

Know a better way?

If you can do better, submit your command here.

What others think

That command gives a string 40 characters long, not 30. You forgot that base64 encoding will always give 4 characters for each 3 bytes (or part thereof) of input.

Comment by Mozai 317 weeks and 4 days ago

You're right. Good call.

Comment by atoponce 317 weeks and 2 days ago

Your point of view

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