Generate a Random Password

openssl rand -base64 32

For example:

$ openssl rand -base64 16

mkK1snmU/Hk4SQGXej94Cg==

Generate a strong password with gpg

We can also use the gpg tool to generate a strong 18 characters password:

gpg --gen-random --armor 1 18

$ pwgen -h

Usage: pwgen [ OPTIONS ] [ pw_length ] [ num_pw ]

Options supported by pwgen:

  -c or --capitalize

        Include at least one capital letter in the password

  -A or --no-capitalize

        Don't include capital letters in the password

  -n or --numerals

        Include at least one number in the password

  -0 or --no-numerals

        Don't include numbers in the password

  -y or --symbols

        Include at least one special symbol in the password

  -r <chars> or --remove-chars=<chars>

        Remove characters from the set of characters to generate passwords

  -s or --secure

        Generate completely random passwords

  -B or --ambiguous

        Don't include ambiguous characters in the password

  -h or --help

        Print a help message

  -H or --sha1=path/to/file[#seed]

        Use sha1 hash of given file as a (not so) random generator

  -C

        Print the generated passwords in columns

  -1

        Don't print the generated passwords in columns

  -v or --no-vowels

        Do not use any vowels so as to avoid accidental nasty words