Simple bash script to safely check passwords against the pwnedpasswords.com API

pwtest.sh

#!/bin/bash

# Get a password from the user...
while read -s -p "Enter password to check or Ctrl-C to quit: " pass2check
do
    # Output a blank line to clean up output...
    echo

    # Get the SHA1 of the entered password...
    sha1sum_output=`echo -n ${pass2check} | sha1sum`

    # Pull apart the head and tail as needed by the pwnedpasswords API...
    hash_prefix=${sha1sum_output:0:5}
    hash_tail=${sha1sum_output:5:35}
    #echo "SHA1: ${sha1sum_output} PREFIX: ${hash_prefix} TAIL: ${hash_tail}"

    # Download that chunk of the hash table and look for a match (output if found)
    wget --quiet "https://api.pwnedpasswords.com/range/${hash_prefix}" -O - | grep -i "${hash_tail}"
done