Here is a program I wrote to learn how to use the Go libraries for AES encryption.
package main
import (
"crypto/aes"
"crypto/cipher"
"encoding/base64"
"log"
)
// AESCipher encrypts and decrypts data using the AES specification.
type AESCipher struct {
stream cipher.Stream
}
// AESDecipher encrypts and decrypts data using the AES specification.
type AESDecipher struct {
stream cipher.Stream
}
// Encrypt encrypts the specified plaintext and returns the ciphertext in base64 format.
func (t *AESCipher) Encrypt(plaintext string) string {
plaintextBytes := []byte(plaintext)
t.stream.XORKeyStream(plaintextBytes, plaintextBytes)
return base64.StdEncoding.EncodeToString(plaintextBytes)
}
// Decrypt decrypts the specified ciphertext (in base64 format) and returns the plaintext.
func (t *AESDecipher) Decrypt(ciphertext string) (string, error) {
ciphertextBytes, err := base64.StdEncoding.DecodeString(ciphertext)
if err != nil {
return "", err
}
t.stream.XORKeyStream(ciphertextBytes, ciphertextBytes)
return string(ciphertextBytes), nil
}
// NewAESCipher creates a new AESCipher with the specified key and initialization vector.
// The key must be 16, 24, or 32 bytes long
// The IV must be 16 bytes long.
func NewAESCipher(key, iv []byte) *AESCipher {
c, err := aes.NewCipher(key)
if err != nil {
panic(err)
}
return &AESCipher{stream: cipher.NewCTR(c, iv)}
}
// NewAESCipher creates a new AESCipher with the specified key and initialization vector.
// The key must be 16, 24, or 32 bytes long
// The IV must be 16 bytes long.
func NewAESDecipher(key, iv []byte) *AESDecipher {
c, err := aes.NewCipher(key)
if err != nil {
panic(err)
}
return &AESDecipher{stream: cipher.NewCTR(c, iv)}
}
func main() {
log.SetFlags(0)
key :=[]byte("hNmicW5oHRgc8ZlWFS0ketaBxke6Eu7O") // 32-byte random string
iv :=[]byte( "0zIZD3VTHnbsv5Mp") // 16-byte random string
enc := NewAESCipher(key, iv)
plaintext := "{\"message\": \"Hello, there!\"}"
ciphertext := enc.Encrypt(plaintext)
log.Printf("Plaintext: %s", plaintext)
log.Printf("Ciphertext: %s", ciphertext)
dec := NewAESDecipher(key, iv)
plaintext2, err := dec.Decrypt(ciphertext)
if err != nil {
log.Fatalf("Unable to decrypt ciphertext: %s", err)
}
log.Printf("Decrypted ciphertext: %s", plaintext2)
}
Build & run
$ go build -o main
$ ./main
Plaintext: {"message": "Hello, there!"}
Ciphertext: t7N5/VgaacwUM6t90hyVkGm0nlEhOeLBf49m+Q==
Decrypted ciphertext: {"message": "Hello, there!"}I hope it helps.