Go Language - AES Encryption And Decryption Example
Advanced Encryption Standard is a symmetric encryption algorithm. AES encryption is used by the U.S. for securing sensitive but unclassified material, so we can say it is enough secure. It allows 128 bit, 192 bit and 256-bit encryption. Symmetric encryption is very fast as compared to asymmetric encryption and are used in systems such as database system.
The following illustration highlights how symmetric cryptography works:
Example:
package main
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/hex"
"fmt"
"io"
)
func main() {
//generate a random 32 byte key
key := GenerateRandomKey()
//your secret text
secret := "This is my password"
//encryption
encrypted := encrypt(secret, key)
fmt.Printf("encrypted data: %s\n", encrypted)
//decryption
decrypted := decrypt(encrypted, key)
fmt.Printf("decrypted data: %s\n", decrypted)
}
//encryption
func encrypt(stringToEncrypt string,
keyString string) (encryptedString string) {
//convert decode it to bytes
key := Decode(keyString)
plaintext := []byte(stringToEncrypt)
//Create a new Cipher Block from the key
block, err := aes.NewCipher(key)
CheckError(err)
//Create a new GCM
aesGCM, err := cipher.NewGCM(block)
CheckError(err)
//Create a nonce.
nonce := make([]byte, aesGCM.NonceSize())
_, err = io.ReadFull(rand.Reader, nonce)
CheckError(err)
//Encrypt the data
ciphertext := aesGCM.
Seal(nonce, nonce, plaintext, nil)
return fmt.Sprintf("%x", ciphertext)
}
//decryption
func decrypt(encryptedString string,
keyString string) (decryptedString string) {
key := Decode(keyString)
enc := Decode(encryptedString)
//Create a new Cipher Block from the key
block, err := aes.NewCipher(key)
CheckError(err)
//Create a new GCM
aesGCM, err := cipher.NewGCM(block)
CheckError(err)
//Get the nonce size
nonceSize := aesGCM.NonceSize()
//Extract the nonce from the encrypted data
nonce, ciphertext := enc[:nonceSize], enc[nonceSize:]
//Decrypt the data
plaintext, err := aesGCM.Open(nil, nonce, ciphertext, nil)
CheckError(err)
return fmt.Sprintf("%s", plaintext)
}
//generate a random 32 byte key
func GenerateRandomKey() string {
bytes := make([]byte, 32)
_, err := rand.Read(bytes)
CheckError(err)
key := hex.EncodeToString(bytes)
return key
}
//Convert to bytes
func Decode(text string) []byte {
bytes, err := hex.DecodeString(text)
CheckError(err)
return bytes
}
func CheckError(err error) {
if err != nil {
panic(err)
}
}
Output:
Author name,
Seril
