sha256

#!/bin/bash

# args 1: data
# args 2: iterations (default 2)

it=2

if [[ -n "$2" ]]; then
	it=$2
fi

h=$(echo -n "$1" | xxd -ps)

for ((i=1;i<=it;i++)); do
	h=$(echo $h | xxd -r -p | sha256sum)
done

echo $h | sed 's/ .*//'