encryption.go

package utils

import (
	"crypto/aes"
	"crypto/cipher"
	"crypto/rand"
	"fmt"
	"io"
)

func EncryptAES(key []byte, plaintext string) []byte {
	cphr, err := aes.NewCipher(key)
	if err != nil {
		fmt.Println(err)
	}
	gcm, err := cipher.NewGCM(cphr)
	if err != nil {
		fmt.Println(err)
	}
	nonce := make([]byte, gcm.NonceSize())
	if _, err = io.ReadFull(rand.Reader, nonce); err != nil {
		fmt.Println(err)
	}

	return gcm.Seal(nonce, nonce, []byte(plaintext), nil)
}

func DecryptAES(key []byte, ct []byte) []byte {
	c, err := aes.NewCipher(key)
	if err != nil {
		fmt.Println(err)
	}
	gcmDecrypt, err := cipher.NewGCM(c)
	if err != nil {
		fmt.Println(err)
	}
	nonceSize := gcmDecrypt.NonceSize()
	if len(ct) < nonceSize {
		fmt.Println(err)
	}
	nonce, encryptedMessage := ct[:nonceSize], ct[nonceSize:]
	plaintext, err := gcmDecrypt.Open(nil, nonce, encryptedMessage, nil)

	return plaintext
}