make key, encrypt, decrypt (openssl)

.gitignore

rand.dat
private.key
public.key

decrypt.sh

#!/bin/bash
if [ $# -eq 0 ]; then
	echo "Usage: decrypt INPUT OUTPUT"
	exit 0
fi

if [ $# -ge 3 ]; then
	echo "error: too many args"
	exit 1
fi

if [ $# -eq 1 ]; then
	export OUT=$1.out
else
	export OUT=$2
fi

echo "decrypting $1"
openssl rsautl -decrypt -inkey private.key -in $1 -out $OUT

encrypt.sh

#!/bin/bash
if [ $# -eq 0 ]; then
	echo "Usage: encrypt INPUT OUTPUT"
	exit 0
fi

if [ $# -ge 3 ]; then
	echo "error: too many args"
	exit 1
fi

if [ $# -eq 1 ]; then
	export OUT=$1.priv
else
	export OUT=$2
fi

echo "encripting $1"
openssl rsautl -encrypt -pubin -inkey public.key -in $1 -out $OUT

mkkeys.sh

#!/bin/bash
if [ $# -ge 2 ]; then
	echo "error: too many args"
	exit 1
fi

if [ -z $1 ]; then
	export BITS=512
else
	export BITS=$1
fi

if echo $1 | grep help >> /dev/null ;then
	echo "usage: ${0} <BITS>"
	echo "BIT is a length of rsa key"
	exit 0
fi

if [ $BITS -le 30 ]; then
	echo "error: key size is too small"
	exit 1
fi

openssl rand 4096 -out rand.dat &&
openssl genrsa -rand rand.dat -out private.key $BITS &&
openssl rsa -in private.key -pubout -out public.key &&
rm rand.dat