@Carlo,

Thanks for the tip, hope these commands helpful to our readers…

< /dev/urandom tr -dc a-zA-Z0-9 | head -c64

This will create a 64 character alphanumeric PSK.

Replace a-zA-Z0-9 with another list of characters and ranges to control which characters occur, and replace 64 with another number to control length.

e.g.

8 lower-case letters

< /dev/urandom tr -dc a-z | head -c8

16 handwriting-unambiguous alphanumeric characters

< /dev/urandom tr -dc a-jmnoqrtyA-HJLMNQRTY2-9 | head -c16

64 alphanumeric characters and all non-space printable ascii symbols (\ escapes the ! for the shell)

< /dev/urandom tr -dc \!-~ | head -c64

64 URL-safe characters (\ escapes the ()'!*; for the shell)

< /dev/urandom tr -dc a-zA-Z0-9-._~\(\)\'\!\*:@,\; | head -c64

date prints strings like “Sun Dec 6 18:05:53 PST 2020”. Since this string changes once per second, in any given day there are only 86,400 potential keys. This is a tiny number of keys that is easy for an attacker to brute force. In comparison “openssl rand -base64 32” has 256^32 potential keys, a vastly larger number that is difficult to brute force (115,792,089,237,316,195,423,570,985,008,687,907,853,269,984,665,640,564,039,457,584,007,913,129,639,936)

@Nooby,

Thanks, corrected the command in the article.

It’s confusing enough without hurting the noob’s brain even more! ;-)

Thank-you.