mirror of https://github.com/mitchell/selfpass.git
63 lines
1.1 KiB
Go
63 lines
1.1 KiB
Go
package crypto
|
|
|
|
import (
|
|
"crypto/aes"
|
|
"crypto/cipher"
|
|
"crypto/rand"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
)
|
|
|
|
var ErrAuthenticationFailed = errors.New("cipher: message authentication failed")
|
|
|
|
func GCMEncrypt(key []byte, plaintext []byte) ([]byte, error) {
|
|
if len(key) != 32 {
|
|
return nil, fmt.Errorf("key is not 32 bytes")
|
|
}
|
|
|
|
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
|
|
}
|
|
|
|
func GCMDecrypt(key []byte, ciphertext []byte) ([]byte, error) {
|
|
if len(key) != 32 {
|
|
return nil, fmt.Errorf("key is not 32 bytes")
|
|
}
|
|
|
|
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,
|
|
)
|
|
}
|