#!/bin/bash

# define the name or IP address of the machine that will receive the files
HOST=foo

# define the user you are running as on both machines
USER=bar

# define a link to tmpfs where there is plenty of RAM free
# by default /tmp is mounted with 1/2 physical memory and this test as written below
# requires approx 1.2G of free space on each end of the test
TMPFS=/tmp

# log file with results
LOGPATH=/home/$USER/cipher_results.csv

# ciphers to test
CIPHERS="aes128-ctr aes192-ctr aes256-ctr aes128-gcm@openssh.com aes256-gcm@openssh.com chacha20-poly1305@openssh.com"

####

# check deps
for i in dd parallel; do
	command -v $i >/dev/null 2>&1 || {
	echo " I require $i but it's not installed. Aborting!" >&2; exit 1; }
done

ping -c 1 $HOST > /dev/null
if [ $? -ne 0 ]; then
  echo "$HOST is down"
  exit 1
fi

make_receipe() {
	# make the 1100M file assembled from 3x10M files in in a pseudo random fashion
	# this should prevent any caching since all files will be unique
	for i in {0..109}; do
		RND=$(echo $[ 1 + $[ RANDOM % 3 ]])
		Array[$i]=$TMPFS/file$RND
	done
}

for cipher in $CIPHERS; do
	echo " --> $cipher"
	parallel "dd if=/dev/urandom of=$TMPFS/file{} bs=1M count=10 &>/dev/null" ::: 1 2 3

	for j in 1 2 3; do
		make_receipe
		cat ${Array[@]} > $TMPFS/part$j
		start=$(date +%s.%N)
		scp -c "$cipher" $TMPFS/part$j $USER@$HOST:$TMPFS
		end=$(date +%s.%N)
		diff=$(echo "scale=6; $end - $start" | bc)
		[[ ! -f $LOG ]] && echo "cipher,round,time(sec),host" > $LOG
		echo "$cipher,$j,$diff,$HOST" >> $LOG
		rm -f $TMPFS/part$j
		ssh $HOST "rm -f $TMPFS/part$j"
	done
done
rm -f $TMPFS/file[1,2,3]