Generate a random password 30 characters long
user@machine:~$ strings /dev/urandom | grep -o '[[:alnum:]]' | head -n 30 | tr -d '\n'; echo XhJjKL07KNZSDDpwdPm9rACnW3FR0w
18 Alternatives + Submit Alt
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-B flag = don't include characters that can be confused for other characters (this helps when you give someone their password for the first time so they don't cause a lockout with, for example, denyhosts or fail2ban) -s flag = make a "secure", or hard-to-crack password -y flag = include special characters (not used in the example because so many people hate it -- however I recommend it) "1 10" = output 1 password, make it 10 characters in length For even more secure passwords please use the -y flag to include special characters like so:
pwgen -Bsy 10 1output>> }&^Y?.>7Wu Show Sample Output15pwgen -Bs 10 1 -
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). Show Sample Output11gpg --gen-random --armor 1 30 -
If you want a password length longer than 6, changing the -c6 to read -c8 will give you 8 random characters instead of 6. To end up with a line-feed, use this with echo: # echo `< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6` Modern systems need higher strenght, so add some special characters: # < /dev/urandom tr -dc '12345!@#$%qwertQWERTasdfgASDFGzxcvbZXCVB' | head -c8
11< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6 -
9cat /dev/urandom | tr -dc A-Za-z0-9 | head -c 32
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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] Show Sample Output
6pwgen 30 1
What do you think?
Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?
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strings /dev/urandom | grep -o '[[:graph:]]' | grep '[^0O1l]' | head -n 20 | tr -d '\n'; echocat /dev/urandom | tr -cd 0-9a-zA-Z | head -c 30it's short and comes handy in scripts, e.g. asigning random names for loops etc.