forked from macaron/session
Andrew Thornton
b8f62d7880
Add samesite cookie options Signed-off-by: Andrew Thornton <art27@cantab.net> Securely encrypt flash cookie to prevent javascript attack Signed-off-by: Andrew Thornton <art27@cantab.net> Reviewed-on: macaron/session#16 Reviewed-by: silverwind <silverwind@noreply.gitea.io> Reviewed-by: 6543 <6543@obermui.de> Co-Authored-By: Andrew Thornton <art27@cantab.net> Co-Committed-By: Andrew Thornton <art27@cantab.net>
101 lines
2.5 KiB
Go
101 lines
2.5 KiB
Go
// Copyright 2019 The Gitea Authors. All rights reserved.
|
|
// Use of this source code is governed by a MIT-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package session
|
|
|
|
import (
|
|
"crypto/aes"
|
|
"crypto/cipher"
|
|
"crypto/rand"
|
|
"crypto/sha256"
|
|
"encoding/base64"
|
|
"errors"
|
|
"io"
|
|
)
|
|
|
|
// NewSecret creates a new secret
|
|
func NewSecret() (string, error) {
|
|
return NewSecretWithLength(32)
|
|
}
|
|
|
|
// NewSecretWithLength creates a new secret for a given length
|
|
func NewSecretWithLength(length int64) (string, error) {
|
|
return randomString(length)
|
|
}
|
|
|
|
func randomBytes(len int64) ([]byte, error) {
|
|
b := make([]byte, len)
|
|
if _, err := rand.Read(b); err != nil {
|
|
return nil, err
|
|
}
|
|
return b, nil
|
|
}
|
|
|
|
func randomString(len int64) (string, error) {
|
|
b, err := randomBytes(len)
|
|
return base64.URLEncoding.EncodeToString(b), err
|
|
}
|
|
|
|
// AesEncrypt encrypts text and given key with AES.
|
|
func AesEncrypt(key, text []byte) ([]byte, error) {
|
|
block, err := aes.NewCipher(key)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
b := base64.StdEncoding.EncodeToString(text)
|
|
ciphertext := make([]byte, aes.BlockSize+len(b))
|
|
iv := ciphertext[:aes.BlockSize]
|
|
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
|
|
return nil, err
|
|
}
|
|
cfb := cipher.NewCFBEncrypter(block, iv)
|
|
cfb.XORKeyStream(ciphertext[aes.BlockSize:], []byte(b))
|
|
return ciphertext, nil
|
|
}
|
|
|
|
// AesDecrypt decrypts text and given key with AES.
|
|
func AesDecrypt(key, text []byte) ([]byte, error) {
|
|
block, err := aes.NewCipher(key)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if len(text) < aes.BlockSize {
|
|
return nil, errors.New("ciphertext too short")
|
|
}
|
|
iv := text[:aes.BlockSize]
|
|
text = text[aes.BlockSize:]
|
|
cfb := cipher.NewCFBDecrypter(block, iv)
|
|
cfb.XORKeyStream(text, text)
|
|
data, err := base64.StdEncoding.DecodeString(string(text))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return data, nil
|
|
}
|
|
|
|
// EncryptSecret encrypts a string with given key into a hex string
|
|
func EncryptSecret(key string, str string) (string, error) {
|
|
keyHash := sha256.Sum256([]byte(key))
|
|
plaintext := []byte(str)
|
|
ciphertext, err := AesEncrypt(keyHash[:], plaintext)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
return base64.StdEncoding.EncodeToString(ciphertext), nil
|
|
}
|
|
|
|
// DecryptSecret decrypts a previously encrypted hex string
|
|
func DecryptSecret(key string, cipherhex string) (string, error) {
|
|
keyHash := sha256.Sum256([]byte(key))
|
|
ciphertext, err := base64.StdEncoding.DecodeString(cipherhex)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
plaintext, err := AesDecrypt(keyHash[:], ciphertext)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
return string(plaintext), nil
|
|
}
|