package main
import (
"bytes"
"crypto/sha256"
"embed"
"fmt"
"net/http"
)
const legalPageStyle = `
`
//go:embed legal/*.html
var legalDocumentFiles embed.FS
type legalDocument struct {
body []byte
etag string
}
var legalDocuments = map[string]legalDocument{
"/legal/user-terms": loadLegalDocument("legal/user-terms.html", "笔墨讯使软件服务协议"),
"/legal/privacy-policy": loadLegalDocument("legal/privacy-policy.html", "笔墨讯使隐私政策"),
}
func loadLegalDocument(name, title string) legalDocument {
body, err := legalDocumentFiles.ReadFile(name)
if err != nil {
panic("load legal document: " + err.Error())
}
body = bytes.Replace(body,
[]byte(""),
[]byte(""), 1)
body = bytes.Replace(body, []byte(""), []byte(""+title+""), 1)
body = bytes.Replace(body, []byte(""), []byte(legalPageStyle+""), 1)
body = bytes.Replace(body, []byte(""),
[]byte(""+title+"
"), 1)
body = bytes.Replace(body, []byte(""), []byte("
"), 1)
digest := sha256.Sum256(body)
return legalDocument{body: body, etag: fmt.Sprintf("\"%x\"", digest[:16])}
}
func serveLegalDocument(wrt http.ResponseWriter, req *http.Request) {
if req.Method != http.MethodGet && req.Method != http.MethodHead {
wrt.Header().Set("Allow", "GET, HEAD")
http.Error(wrt, "method not allowed", http.StatusMethodNotAllowed)
return
}
document, ok := legalDocuments[req.URL.Path]
if !ok {
http.NotFound(wrt, req)
return
}
wrt.Header().Set("Content-Type", "text/html; charset=utf-8")
wrt.Header().Set("Cache-Control", "public, max-age=300, must-revalidate")
wrt.Header().Set("Content-Security-Policy", "default-src 'none'; style-src 'unsafe-inline'; img-src data:; base-uri 'none'; form-action 'none'")
wrt.Header().Set("Referrer-Policy", "no-referrer")
wrt.Header().Set("X-Content-Type-Options", "nosniff")
wrt.Header().Set("ETag", document.etag)
if req.Header.Get("If-None-Match") == document.etag {
wrt.WriteHeader(http.StatusNotModified)
return
}
if req.Method == http.MethodHead {
wrt.Header().Set("Content-Length", fmt.Sprintf("%d", len(document.body)))
return
}
_, _ = wrt.Write(document.body)
}