PwnedPasswords API Checker (Bash)

passcheck.sh

#!/bin/bash

# This script checks the haveibeenpwned 'PwnedPasswords'
# API based on the first 5 characters of your password's
# SHA-1 hash, then plucks out a full match from the hash
# suffixes returned by the API (assuming there are any).
# If your password's hash is found, it'll return pwncount.
#
# Either replace $1 with password, or call from shell 
# as ` ./passcheck "mypass" - note the preceeding space
# to prevent the command being appended to the history!
#
PASSWD=$1

SHAFUL=$(echo -n $PASSWD | sha1sum | awk '{print $1}')
SHAPRE=$(echo $SHAFUL | awk '{print substr($1,0,5)}')
SHASUF=$(echo $SHAFUL | awk '{print substr($1,6)}')

echo "Searching Pwned Passwords API for SHA-1 prefix '$SHAPRE'"
echo "  Full hash: $SHAFUL"
echo

RESPONSE=$(curl "https://api.pwnedpasswords.com/range/$SHAPRE" 2>/dev/null | \grep -i "$SHASUF")

echo ${RESPONSE#*:}