#!/bin/sh

exit_msg() {
        echo $1
        exit $2
}

ask_passwd() {
        stty -echo
        echo -n "Enter password:"
        read PASSWD1
        echo
        echo -n "Confirm password:"
        read PASSWD2
        echo

        if [ "$PASSWD1" != "$PASSWD2" ]; then
                exit_msg "Password mismatch" 1
        fi
        PASSWORD=$PASSWD1
        stty echo
}

usage() {
        echo "$0 [ -c ] [ -m ] [ -D ] passwdfile username"
        echo "$0 -b [ -c ] [ -m | -d | -p | -s ] [ -D ] passwdfile username password"
        echo "$0 -nb [ -m | -d | -s | -p ] username password"

        exit 1
}

while getopts "bcdmnpsD" FLAG; do
        case "$FLAG" in
                b)      BATCH_MODE=bopt ;;
                c)      CREATE_PASSWD=copt ;;
                d)      ALGO=crypt;;
                n)      DISPLAY_RESULT=nopt ;;
                m)      ALGO=md5;;
                s)      ALGO=sha;;
                p)      ALGO=plaintext;;
                D)      DELETE_USER=Dopt;;
                *)      usage;;
        esac
done

shift $(( $OPTIND - 1 ))

test -z "${ALGO}" && ALGO=crypt

case "${DISPLAY_RESULT}${BATCH_MODE}$#" in
        noptbopt2)
                USERNAME=$1
                PASSWORD=$2
                ;;
        bopt3)
                FILE=$1
                USERNAME=$2
                PASSWORD=$3
                ;;
        nopt1)
                USERNAME=$1
                ;;
        bopt2|2)
                FILE=$1
                USERNAME=$2
                ;;
        *) usage;;
esac

case "${DISPLAY_RESULT}${CREATE_PASSWD}" in
        noptcopt)
                echo "you cannot display the result and create the passwd file"
                exit 1
                ;;
        nopt|copt) ;;
        *)
                test -f ${FILE} || exit_msg "File ${FILE} not found, use -c option to create it" 1
                ;;
esac

test -z $PASSWORD && ask_passwd

case "$ALGO" in
        crypt)
                GENPASSWD=$(openssl passwd -crypt ${PASSWORD})
                ;;
        md5)
                GENPASSWD=$(openssl passwd -apr1 ${PASSWORD})
                ;;
       sha)
                GENPASSWD="{SHA}$(echo -n ${PASSWORD} | openssl dgst -sha1 -binary | openssl base64)"
                ;;
        plaintext)
                GENPASSWD=$PASSWORD
                ;;
esac

test -n "$DISPLAY_RESULT" && exit_msg "${USERNAME}:${GENPASSWD}" 0

case "${CREATE_PASSWD}" in
        copt)
                echo "${USERNAME}:${GENPASSWD}" > $FILE
                ;;
        *)
                echo "${USERNAME}:${GENPASSWD}" >> $FILE
                ;;
esac

exit 0