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gita/modules/web/middleware/locale.go
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chore: initialize Gitea v1.27.2 fork
Includes direct password setup links in registration emails.

Assisted-by: Codex:GPT-5
2026-08-15 22:56:18 +08:00

72 lines
2.1 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package middleware
import (
"net/http"
"gitea.dev/modules/translation"
"gitea.dev/modules/translation/i18n"
"golang.org/x/text/language"
)
// maxAcceptLanguageLen bounds the Accept-Language header before it reaches
// language.ParseAcceptLanguage. That parser has quadratic-time behavior on long
// malformed inputs, and its built-in guard only counts "-" separators while the
// scanner treats "_" as an alias for "-", so a "_"-heavy header slips past the
// guard and burns CPU. Only the leading (highest-priority) languages are used, so
// truncating a longer header is safe.
const maxAcceptLanguageLen = 200
// parseAcceptLanguage parses the Accept-Language header after bounding its length
// to avoid a quadratic-time DoS on attacker-controlled input.
func parseAcceptLanguage(header string) []language.Tag {
if len(header) > maxAcceptLanguageLen {
header = header[:maxAcceptLanguageLen]
}
tags, _, _ := language.ParseAcceptLanguage(header)
return tags
}
// Locale handle locale
func Locale(resp http.ResponseWriter, req *http.Request) translation.Locale {
// 1. Check URL arguments.
lang := req.URL.Query().Get("lang")
changeLang := lang != ""
// 2. Get language information from cookies.
if len(lang) == 0 {
ck, _ := req.Cookie("lang")
if ck != nil {
lang = ck.Value
}
}
// Check again in case someone changes the supported language list.
if lang != "" && !i18n.DefaultLocales.HasLang(lang) {
lang = ""
changeLang = false
}
// 3. Get language information from 'Accept-Language'.
// The first element in the list is chosen to be the default language automatically.
if len(lang) == 0 {
tags := parseAcceptLanguage(req.Header.Get("Accept-Language"))
tag := translation.Match(tags...)
lang = tag.String()
}
if changeLang {
SetLocaleCookie(resp, lang, 1<<31-1)
}
return translation.NewLocale(lang)
}
// SetLocaleCookie convenience function to set the locale cookie consistently
func SetLocaleCookie(resp http.ResponseWriter, lang string, maxAge int) {
SetSiteCookie(resp, "lang", lang, maxAge)
}