A fork of Gitea (see branch `mj`) adding Majority Judgment Polls 𐄷 over Issues and Merge Requests. https://git.mieuxvoter.fr
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// Copyright 2013 Martini Authors
// Copyright 2014 The Macaron Authors
// Copyright 2021 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.
// a middleware that generates and validates CSRF tokens.
package context
import (
"net/http"
"time"
"code.gitea.io/gitea/modules/web/middleware"
"github.com/unknwon/com"
)
// CSRF represents a CSRF service and is used to get the current token and validate a suspect token.
type CSRF interface {
// Return HTTP header to search for token.
GetHeaderName() string
// Return form value to search for token.
GetFormName() string
// Return cookie name to search for token.
GetCookieName() string
// Return cookie path
GetCookiePath() string
// Return the flag value used for the csrf token.
GetCookieHTTPOnly() bool
// Return cookie domain
GetCookieDomain() string
// Return the token.
GetToken() string
// Validate by token.
ValidToken(t string) bool
// Error replies to the request with a custom function when ValidToken fails.
Error(w http.ResponseWriter)
}
type csrf struct {
// Header name value for setting and getting csrf token.
Header string
// Form name value for setting and getting csrf token.
Form string
// Cookie name value for setting and getting csrf token.
Cookie string
//Cookie domain
CookieDomain string
//Cookie path
CookiePath string
// Cookie HttpOnly flag value used for the csrf token.
CookieHTTPOnly bool
// Token generated to pass via header, cookie, or hidden form value.
Token string
// This value must be unique per user.
ID string
// Secret used along with the unique id above to generate the Token.
Secret string
// ErrorFunc is the custom function that replies to the request when ValidToken fails.
ErrorFunc func(w http.ResponseWriter)
}
// GetHeaderName returns the name of the HTTP header for csrf token.
func (c *csrf) GetHeaderName() string {
return c.Header
}
// GetFormName returns the name of the form value for csrf token.
func (c *csrf) GetFormName() string {
return c.Form
}
// GetCookieName returns the name of the cookie for csrf token.
func (c *csrf) GetCookieName() string {
return c.Cookie
}
// GetCookiePath returns the path of the cookie for csrf token.
func (c *csrf) GetCookiePath() string {
return c.CookiePath
}
// GetCookieHTTPOnly returns the flag value used for the csrf token.
func (c *csrf) GetCookieHTTPOnly() bool {
return c.CookieHTTPOnly
}
// GetCookieDomain returns the flag value used for the csrf token.
func (c *csrf) GetCookieDomain() string {
return c.CookieDomain
}
// GetToken returns the current token. This is typically used
// to populate a hidden form in an HTML template.
func (c *csrf) GetToken() string {
return c.Token
}
// ValidToken validates the passed token against the existing Secret and ID.
func (c *csrf) ValidToken(t string) bool {
return ValidToken(t, c.Secret, c.ID, "POST")
}
// Error replies to the request when ValidToken fails.
func (c *csrf) Error(w http.ResponseWriter) {
c.ErrorFunc(w)
}
// CsrfOptions maintains options to manage behavior of Generate.
type CsrfOptions struct {
// The global secret value used to generate Tokens.
Secret string
// HTTP header used to set and get token.
Header string
// Form value used to set and get token.
Form string
// Cookie value used to set and get token.
Cookie string
// Cookie domain.
CookieDomain string
// Cookie path.
CookiePath string
CookieHTTPOnly bool
// SameSite set the cookie SameSite type
SameSite http.SameSite
// Key used for getting the unique ID per user.
SessionKey string
// oldSessionKey saves old value corresponding to SessionKey.
oldSessionKey string
// If true, send token via X-CSRFToken header.
SetHeader bool
// If true, send token via _csrf cookie.
SetCookie bool
// Set the Secure flag to true on the cookie.
Secure bool
// Disallow Origin appear in request header.
Origin bool
// The function called when Validate fails.
ErrorFunc func(w http.ResponseWriter)
// Cookie life time. Default is 0
CookieLifeTime int
}
func prepareOptions(options []CsrfOptions) CsrfOptions {
var opt CsrfOptions
if len(options) > 0 {
opt = options[0]
}
// Defaults.
if len(opt.Secret) == 0 {
opt.Secret = string(com.RandomCreateBytes(10))
}
if len(opt.Header) == 0 {
opt.Header = "X-CSRFToken"
}
if len(opt.Form) == 0 {
opt.Form = "_csrf"
}
if len(opt.Cookie) == 0 {
opt.Cookie = "_csrf"
}
if len(opt.CookiePath) == 0 {
opt.CookiePath = "/"
}
if len(opt.SessionKey) == 0 {
opt.SessionKey = "uid"
}
opt.oldSessionKey = "_old_" + opt.SessionKey
if opt.ErrorFunc == nil {
opt.ErrorFunc = func(w http.ResponseWriter) {
http.Error(w, "Invalid csrf token.", http.StatusBadRequest)
}
}
return opt
}
// Csrfer maps CSRF to each request. If this request is a Get request, it will generate a new token.
// Additionally, depending on options set, generated tokens will be sent via Header and/or Cookie.
func Csrfer(opt CsrfOptions, ctx *Context) CSRF {
opt = prepareOptions([]CsrfOptions{opt})
x := &csrf{
Secret: opt.Secret,
Header: opt.Header,
Form: opt.Form,
Cookie: opt.Cookie,
CookieDomain: opt.CookieDomain,
CookiePath: opt.CookiePath,
CookieHTTPOnly: opt.CookieHTTPOnly,
ErrorFunc: opt.ErrorFunc,
}
if opt.Origin && len(ctx.Req.Header.Get("Origin")) > 0 {
return x
}
x.ID = "0"
uid := ctx.Session.Get(opt.SessionKey)
if uid != nil {
x.ID = com.ToStr(uid)
}
needsNew := false
oldUID := ctx.Session.Get(opt.oldSessionKey)
if oldUID == nil || oldUID.(string) != x.ID {
needsNew = true
_ = ctx.Session.Set(opt.oldSessionKey, x.ID)
} else {
// If cookie present, map existing token, else generate a new one.
if val := ctx.GetCookie(opt.Cookie); len(val) > 0 {
// FIXME: test coverage.
x.Token = val
} else {
needsNew = true
}
}
if needsNew {
// FIXME: actionId.
x.Token = GenerateToken(x.Secret, x.ID, "POST")
if opt.SetCookie {
var expires interface{}
if opt.CookieLifeTime == 0 {
expires = time.Now().AddDate(0, 0, 1)
}
middleware.SetCookie(ctx.Resp, opt.Cookie, x.Token,
opt.CookieLifeTime,
opt.CookiePath,
opt.CookieDomain,
opt.Secure,
opt.CookieHTTPOnly,
expires,
middleware.SameSite(opt.SameSite),
)
}
}
if opt.SetHeader {
ctx.Resp.Header().Add(opt.Header, x.Token)
}
return x
}
// Validate should be used as a per route middleware. It attempts to get a token from a "X-CSRFToken"
// HTTP header and then a "_csrf" form value. If one of these is found, the token will be validated
// using ValidToken. If this validation fails, custom Error is sent in the reply.
// If neither a header or form value is found, http.StatusBadRequest is sent.
func Validate(ctx *Context, x CSRF) {
if token := ctx.Req.Header.Get(x.GetHeaderName()); len(token) > 0 {
if !x.ValidToken(token) {
// Delete the cookie
middleware.SetCookie(ctx.Resp, x.GetCookieName(), "",
-1,
x.GetCookiePath(),
x.GetCookieDomain()) // FIXME: Do we need to set the Secure, httpOnly and SameSite values too?
x.Error(ctx.Resp)
}
return
}
if token := ctx.Req.FormValue(x.GetFormName()); len(token) > 0 {
if !x.ValidToken(token) {
// Delete the cookie
middleware.SetCookie(ctx.Resp, x.GetCookieName(), "",
-1,
x.GetCookiePath(),
x.GetCookieDomain()) // FIXME: Do we need to set the Secure, httpOnly and SameSite values too?
x.Error(ctx.Resp)
}
return
}
http.Error(ctx.Resp, "Bad Request: no CSRF token present", http.StatusBadRequest)
}