mirror of
https://github.com/go-gitea/gitea
synced 2024-12-27 08:34:19 +01:00
84ceaa98bd
Do a refactoring to the CSRF related code, remove most unnecessary functions. Parse the generated token's issue time, regenerate the token every a few minutes.
98 lines
3.2 KiB
Go
98 lines
3.2 KiB
Go
// Copyright 2012 Google Inc. All Rights Reserved.
|
|
// Copyright 2014 The Macaron Authors
|
|
// Copyright 2020 The Gitea Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package context
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/hmac"
|
|
"crypto/sha1"
|
|
"crypto/subtle"
|
|
"encoding/base64"
|
|
"fmt"
|
|
"strconv"
|
|
"strings"
|
|
"time"
|
|
)
|
|
|
|
// CsrfTokenTimeout represents the duration that XSRF tokens are valid.
|
|
// It is exported so clients may set cookie timeouts that match generated tokens.
|
|
const CsrfTokenTimeout = 24 * time.Hour
|
|
|
|
// CsrfTokenRegenerationInterval is the interval between token generations, old tokens are still valid before CsrfTokenTimeout
|
|
var CsrfTokenRegenerationInterval = 10 * time.Minute
|
|
|
|
var csrfTokenSep = []byte(":")
|
|
|
|
// GenerateCsrfToken returns a URL-safe secure XSRF token that expires in CsrfTokenTimeout hours.
|
|
// key is a secret key for your application.
|
|
// userID is a unique identifier for the user.
|
|
// actionID is the action the user is taking (e.g. POSTing to a particular path).
|
|
func GenerateCsrfToken(key, userID, actionID string, now time.Time) string {
|
|
nowUnixNano := now.UnixNano()
|
|
nowUnixNanoStr := strconv.FormatInt(nowUnixNano, 10)
|
|
h := hmac.New(sha1.New, []byte(key))
|
|
h.Write([]byte(strings.ReplaceAll(userID, ":", "_")))
|
|
h.Write(csrfTokenSep)
|
|
h.Write([]byte(strings.ReplaceAll(actionID, ":", "_")))
|
|
h.Write(csrfTokenSep)
|
|
h.Write([]byte(nowUnixNanoStr))
|
|
tok := fmt.Sprintf("%s:%s", h.Sum(nil), nowUnixNanoStr)
|
|
return base64.RawURLEncoding.EncodeToString([]byte(tok))
|
|
}
|
|
|
|
func ParseCsrfToken(token string) (issueTime time.Time, ok bool) {
|
|
data, err := base64.RawURLEncoding.DecodeString(token)
|
|
if err != nil {
|
|
return time.Time{}, false
|
|
}
|
|
|
|
pos := bytes.LastIndex(data, csrfTokenSep)
|
|
if pos == -1 {
|
|
return time.Time{}, false
|
|
}
|
|
nanos, err := strconv.ParseInt(string(data[pos+1:]), 10, 64)
|
|
if err != nil {
|
|
return time.Time{}, false
|
|
}
|
|
return time.Unix(0, nanos), true
|
|
}
|
|
|
|
// ValidCsrfToken returns true if token is a valid and unexpired token returned by Generate.
|
|
func ValidCsrfToken(token, key, userID, actionID string, now time.Time) bool {
|
|
issueTime, ok := ParseCsrfToken(token)
|
|
if !ok {
|
|
return false
|
|
}
|
|
|
|
// Check that the token is not expired.
|
|
if now.Sub(issueTime) >= CsrfTokenTimeout {
|
|
return false
|
|
}
|
|
|
|
// Check that the token is not from the future.
|
|
// Allow 1-minute grace period in case the token is being verified on a
|
|
// machine whose clock is behind the machine that issued the token.
|
|
if issueTime.After(now.Add(1 * time.Minute)) {
|
|
return false
|
|
}
|
|
|
|
expected := GenerateCsrfToken(key, userID, actionID, issueTime)
|
|
|
|
// Check that the token matches the expected value.
|
|
// Use constant time comparison to avoid timing attacks.
|
|
return subtle.ConstantTimeCompare([]byte(token), []byte(expected)) == 1
|
|
}
|