Re: One-line password generator

[Aaron Toponce]

On Tue, Aug 22, 2017 at 10:04:59AM -0500, Mario Castelán Castro wrote:
> I have the following line in my Bash init file:
> 
> “alias gen-password="head -c 16 /dev/urandom | base64 | head -c 22 && echo"”
> 
> This generates a password with just above 128 bits of entropy. You may
> find it useful.

Three POSIX-compliant shell functions that rely on no extra utilities outside
of standard base installs. shuff() is needed for some BSD systems where
shuffle(1) is used in place of shuf(1):

    shuff () {
        if [ $(command -v shuf) ]
        then
            shuf -n "$1"
        elif [ $(command -v shuffle) ]
        then
            shuffle -f /dev/stdin -p "$1"
        else
            awk 'BEGIN{
                "od -tu4 -N4 -A n /dev/urandom" | getline
                srand(0+$0)
            }
            {print rand()"\t"$0}' | sort -n | cut -f 2 | head -n "$1"
        fi
    }
    gen_monkey_pass () {
        I=0 
        [ $(printf "$1" | grep -E '[0-9]+') ] && NUM="$1" || NUM="1" 
        until [ "$I" -eq "$NUM" ]
        do
            I=$((I+1)) 
            LC_CTYPE=C strings /dev/urandom | grep -o '[a-hjkmnp-z2-9-]' | head 
-n 24 | paste -s -d \\0 /dev/stdin
        done | column
    }
    gen_xkcd_pass () {
        I=0 
        [ $(printf "$1" | grep -E '[0-9]+') ] && NUM="$1" || NUM="1" 
        [ $(uname) = "SunOS" ] && FILE="/usr/dict/words" || 
FILE="/usr/share/dict/words" 
        DICT=$(LC_CTYPE=C grep -E '^[a-zA-Z]{3,6}$' "$FILE") 
        until [ "$I" -eq "$NUM" ]
        do
            I=$((I+1)) 
            printf "$DICT" | shuff 6 | paste -s -d '.' /dev/stdin
        done | column
    }

They can optionally take an argument on how many passwords to generate:

    $ gen_monkey_pass 10
    rq5xm9b7-jn2-s76-v7rymj2    pe9txqkuprr3nn9yczsp23rb
    uxsx4-673xcv7wkeu7c8g66k    88qd-y549n5pg3g87v33yetw
    tbf6nrnbub8q39wqt943cjas    ts64jgxjw7ut84--2cw6uzxj
    vk4am2pr8nbuvr3e4gk7tsnm    uhdsby7838gkgpnqjzvy73jm
    2ckgppd7c2uasbd598-44z6z    se8-74smtafh4h9dmeyschkc

    $ gen_xkcd_pass 10
    irking.bidets.listen.Soyuz.dahlia.supped
    boob.lacing.peyote.glob.lack.trifle
    shirt.gushed.Aron.notch.agates.Fergus
    hewed.burlap.wales.beck.prisms.rangy
    route.retook.gills.cilium.wadis.gem
    stools.scurf.lugged.mooch.skater.throng
    heist.bye.Google.shyly.Tutsi.rip
    taboo.queues.totes.moors.Suzhou.newest
    sawyer.gill.clutch.opts.zits.larch
    Eisner.sulks.Bradly.Schulz.Adler.puking

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