|  | @@ -19,9 +19,7 @@ import (
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				|  |  |  	"crypto/aes"
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				|  |  |  	"crypto/cipher"
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				|  |  |  	"crypto/rand"
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				|  |  | -	"encoding/base64"
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				|  |  |  	"errors"
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				|  |  | -	"io"
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				|  |  |  	r "math/rand"
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				|  |  |  	"strconv"
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				|  |  |  	"strings"
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				|  | @@ -30,41 +28,53 @@ import (
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				|  |  |  	"unicode/utf8"
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				|  |  |  )
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				|  |  |  
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				|  |  | -// AESEncrypt encrypts text and given key with AES.
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				|  |  | -func AESEncrypt(key, text []byte) ([]byte, error) {
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				|  |  | +// AESGCMEncrypt encrypts plaintext with the given key using AES in GCM mode.
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				|  |  | +func AESGCMEncrypt(key, plaintext []byte) ([]byte, error) {
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				|  |  |  	block, err := aes.NewCipher(key)
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				|  |  |  	if err != nil {
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				|  |  |  		return nil, err
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				|  |  |  	}
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				|  |  | -	b := base64.StdEncoding.EncodeToString(text)
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				|  |  | -	ciphertext := make([]byte, aes.BlockSize+len(b))
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				|  |  | -	iv := ciphertext[:aes.BlockSize]
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				|  |  | -	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
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				|  |  | +
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				|  |  | +	gcm, err := cipher.NewGCM(block)
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				|  |  | +	if err != nil {
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				|  |  |  		return nil, err
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				|  |  |  	}
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				|  |  | -	cfb := cipher.NewCFBEncrypter(block, iv)
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				|  |  | -	cfb.XORKeyStream(ciphertext[aes.BlockSize:], []byte(b))
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				|  |  | -	return ciphertext, nil
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				|  |  | +
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				|  |  | +	nonce := make([]byte, gcm.NonceSize())
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				|  |  | +	if _, err := rand.Read(nonce); err != nil {
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				|  |  | +		return nil, err
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				|  |  | +	}
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				|  |  | +
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				|  |  | +	ciphertext := gcm.Seal(nil, nonce, plaintext, nil)
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				|  |  | +	return append(nonce, ciphertext...), nil
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				|  |  |  }
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				|  |  |  
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				|  |  | -// AESDecrypt decrypts text and given key with AES.
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				|  |  | -func AESDecrypt(key, text []byte) ([]byte, error) {
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				|  |  | +// AESGCMDecrypt decrypts ciphertext with the given key using AES in GCM mode.
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				|  |  | +func AESGCMDecrypt(key, ciphertext []byte) ([]byte, error) {
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				|  |  |  	block, err := aes.NewCipher(key)
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				|  |  |  	if err != nil {
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				|  |  |  		return nil, err
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				|  |  |  	}
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				|  |  | -	if len(text) < aes.BlockSize {
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				|  |  | -		return nil, errors.New("ciphertext too short")
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				|  |  | +
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				|  |  | +	gcm, err := cipher.NewGCM(block)
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				|  |  | +	if err != nil {
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				|  |  | +		return nil, err
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				|  |  | +	}
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				|  |  | +
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				|  |  | +	size := gcm.NonceSize()
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				|  |  | +	if len(ciphertext)-size <= 0 {
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				|  |  | +		return nil, errors.New("Ciphertext is empty")
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				|  |  |  	}
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				|  |  | -	iv := text[:aes.BlockSize]
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				|  |  | -	text = text[aes.BlockSize:]
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				|  |  | -	cfb := cipher.NewCFBDecrypter(block, iv)
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				|  |  | -	cfb.XORKeyStream(text, text)
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				|  |  | -	data, err := base64.StdEncoding.DecodeString(string(text))
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				|  |  | +
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				|  |  | +	nonce := ciphertext[:size]
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				|  |  | +	ciphertext = ciphertext[size:]
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				|  |  | +
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				|  |  | +	plainText, err := gcm.Open(nil, nonce, ciphertext, nil)
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				|  |  |  	if err != nil {
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				|  |  |  		return nil, err
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				|  |  |  	}
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				|  |  | -	return data, nil
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				|  |  | +
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				|  |  | +	return plainText, nil
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				|  |  |  }
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				|  |  |  
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				|  |  |  // IsLetter returns true if the 'l' is an English letter.
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