Passcheck.sh

#!/bin/bash

###
# Checks provided password against breach database
###

function pc() {
 if [[ -z $@ ]]; then
   echo -n Password:
   read -s password
 else
   password="$@"
 fi
 hash="$(echo -n $password | openssl sha1 | awk '{print $2}')"
 upperCase="$(echo $hash | tr '[a-z]' '[A-Z]')"
 prefix="${upperCase:0:5}"
 response=$(curl -s https://api.pwnedpasswords.com/range/$prefix)
 while read -r line; do
   lineOriginal="$prefix$line"
   if [ "${lineOriginal:0:40}" == "$upperCase" ]; then
     echo -e "\nPassword breached."
     return 1;
   fi
 done <<< "$response"
 echo -e "\nPassword not found in breached database."
}

pc "$@"