#!/bin/bash
# PACKAGES NEEDDED: argon2, cracklib-check, xxd?

time_cost=3 # time cost (iterations)
memory_cost=16 # 2^n KiB ex 16 = 64 MiB (mem usage)
paralellization_cost=1 # threads
salt_min_length=40

read -p "Input File to prove authorship of:" file
if [ ! -f "$file" ]; then
    echo "$file not found!"
    exit 1
else
    echo "File: OK"
    file=$(realpath $file)
fi

# gather salt
read -s -p "Input Secret Salt" salt1
read -s -p "Re-Enter Secret Salt" salt2
## Sanity check the salt
### not empty
if [ -z "$salt1" -o -z "$salt2" ]; then
    echo "Input salts can NOT be blank!"
    exit 1
else
    echo "Salt Supplied: OK"
fi
### match
if [[ "$salt1" != "$salt2" ]]; then
    echo "Salts DO NOT MATCH"
    exit 1
else
    echo "Salts match: OK"
fi
### length
salt_length=${#salt1} # salt len
if [[ $salt_length -le $salt_min_length ]]; then
    echo "Salt MUST be $salt_min_length characters or longer!"
    exit 1
else
    echo "Salt Length: OK"
fi
### salt safety and complexity
complexity_check=$(echo -n "$salt1" | cracklib-check)
if grep -q 'OK' <<< "$complexity_check"; then
    echo "Complexity: OK"
else
    echo "Salt NOT Complex enough!"
    exit 1
fi

argon2 "$salt1" -id -t $time_cost -m $memory_cost -p $paralellization_cost -e
 < "$file"

## cleanup
unset $salt1
unset $salt2
unset $salt_length
echo "DONE"
exit 0