#!/usr/bin/env nix-shell
#!nix-shell -i bash -p bash openssl

# Check if the user provided a file name as an argument
if [ $# -eq 0 ]; then
    echo "Expected usage: decrypt.sh <filename>"
    exit 1
fi

# Store the provided filename in a variable
file_name="$1"

# Check if the provided argument is a file and not a folder
if [ ! -f "$file_name" ]; then
    echo "Error: '$file_name' is not a valid file. Look inside the 'files' folder with 'ls -R'!"
    exit 1
fi

# If there's an error reading the file, print an error message
if ! openssl enc -d -aes-256-cbc -pbkdf2 -iter 100000 -salt -in "$file_name" -k picoCTF; then
    echo "Error: Failed to decrypt '$file_name'. This flag is fake! Keep looking!"
fi