AES-256-cbc terminal encryption

protect.sh

#!/bin/bash
#encrypt files with aes-256-cbc cipher using openssl

#encrypt files
if [ $1 == "-e" ];
then
    if [ -f "$2" ];
    then
    openssl aes-256-cbc -a -e -salt -in "$2" -out "$2.aes"
    else
       echo "This file does not exist!" 
    fi
#decrypt files
elif [ $1 == "-d" ];
then
    if [ -f "$2" ];
    then
        openssl aes-256-cbc -a -d -salt -in "$2" -out "$2.decrypt"
    else
        echo "This file does not exist!" 
    fi
#show help
elif [ $1 == "--help" ];
then
    echo "This software uses openssl for encrypting files with the aes-256-cbc cipher"
    echo "Usage for encrypting: ./encrypt -e [file]"
    echo "Usage for decrypting: ./encrypt -d [file]"
else
    echo "This action does not exist!"
    echo "Use ./encrypt --help to show help."
fi

terminal

# encrypt file.txt to file.enc using 256-bit AES in CBC mode
openssl enc -aes-256-cbc -salt -in file.txt -out file.enc

# the same, only the output is base64 encoded for, e.g., e-mail
openssl enc -aes-256-cbc -a -salt -in file.txt -out file.enc

# decrypt binary file.enc
openssl enc -d -aes-256-cbc -in file.enc -out file.txt

# decrypt base64-encoded version
openssl enc -d -aes-256-cbc -a -in file.enc -out file.txt