58 lines
1.3 KiB
Go
58 lines
1.3 KiB
Go
|
package utils
|
||
|
|
|
||
|
|
import (
|
||
|
|
"crypto/aes"
|
||
|
|
"crypto/cipher"
|
||
|
|
"crypto/rand"
|
||
|
|
"errors"
|
||
|
|
"io"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Encrypt encrypts data using 256-bit AES-GCM. This both hides the content of
|
||
|
|
// the data and provides a check that it hasn't been altered. Output takes the
|
||
|
|
// form nonce|ciphertext|tag where '|' indicates concatenation.
|
||
|
|
func Encrypt(plaintext []byte, key *[32]byte) (ciphertext []byte, err error) {
|
||
|
|
block, err := aes.NewCipher(key[:])
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
gcm, err := cipher.NewGCM(block)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
nonce := make([]byte, gcm.NonceSize())
|
||
|
|
_, err = io.ReadFull(rand.Reader, nonce)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
return gcm.Seal(nonce, nonce, plaintext, nil), nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// Decrypt decrypts data using 256-bit AES-GCM. This both hides the content of
|
||
|
|
// the data and provides a check that it hasn't been altered. Expects input
|
||
|
|
// form nonce|ciphertext|tag where '|' indicates concatenation.
|
||
|
|
func Decrypt(ciphertext []byte, key *[32]byte) (plaintext []byte, err error) {
|
||
|
|
block, err := aes.NewCipher(key[:])
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
gcm, err := cipher.NewGCM(block)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
if len(ciphertext) < gcm.NonceSize() {
|
||
|
|
return nil, errors.New("malformed ciphertext")
|
||
|
|
}
|
||
|
|
|
||
|
|
return gcm.Open(nil,
|
||
|
|
ciphertext[:gcm.NonceSize()],
|
||
|
|
ciphertext[gcm.NonceSize():],
|
||
|
|
nil,
|
||
|
|
)
|
||
|
|
}
|