benignware.go

package main

import (
	"crypto/aes"
	"crypto/cipher"
	"crypto/rand"
	"fmt"
	"github.com/urfave/cli/v2"
	"io"
	"io/ioutil"
	"log"
	"os"
)

func GenerateKey() []byte {
	token := make([]byte, 16)
	rand.Read(token)
	return token
}

func EncryptFile(c *cli.Context) error {
	key := GenerateKey()
	fmt.Println(string(key))

	homeDir, err := os.UserHomeDir()
	if err != nil {
		log.Fatal(err)
	}

	// Create file to encrypt
	filename := fmt.Sprintf("%s/Desktop/%s", homeDir, c.String("filename"))
	dat, err := os.ReadFile(filename)
	if err != nil {
		return err
	}

	block, err := aes.NewCipher(key)
	if err != nil {
		return err
	}

	gcm, err := cipher.NewGCM(block)
	if err != nil {
		return err
	}

	nonce := make([]byte, gcm.NonceSize())
	if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
		return err
	}

	ciphertext := gcm.Seal(nonce, nonce, dat, nil)
	// Save back to file
	encryptedFilePath := fmt.Sprintf("%s.bin", filename)
	err = ioutil.WriteFile(encryptedFilePath, ciphertext, 0777)
	if err != nil {
		return err
	}

	return nil
}