129 lines
2.8 KiB
Go
129 lines
2.8 KiB
Go
package main
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/hmac"
|
|
"crypto/sha1"
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
"log"
|
|
"net/http"
|
|
"regexp"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
// HubBackend handles information for the incoming handler
|
|
type HubBackend interface {
|
|
CreateFeed(url, channel string) (int64, error)
|
|
GetSecret(feedID int64) string
|
|
UpdateFeed(feedID int64, contentType string, body io.Reader) error
|
|
FeedSetLeaseSeconds(feedID int64, leaseSeconds int64) error
|
|
}
|
|
|
|
type incomingHandler struct {
|
|
Backend HubBackend
|
|
}
|
|
|
|
var (
|
|
urlRegex = regexp.MustCompile(`^/incoming/(\d+)$`)
|
|
)
|
|
|
|
func (h *incomingHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
|
|
defer r.Body.Close()
|
|
|
|
r.ParseForm()
|
|
log.Printf("%s %s\n", r.Method, r.URL)
|
|
log.Println(r.URL.Query())
|
|
log.Println(r.PostForm)
|
|
|
|
// find feed
|
|
matches := urlRegex.FindStringSubmatch(r.URL.Path)
|
|
feed, err := strconv.ParseInt(matches[1], 10, 64)
|
|
if err != nil {
|
|
fmt.Fprint(w, err)
|
|
}
|
|
|
|
if r.Method == http.MethodGet {
|
|
values := r.URL.Query()
|
|
|
|
// check
|
|
if leaseStr := values.Get("hub.lease_seconds"); leaseStr != "" {
|
|
// update lease_seconds
|
|
|
|
leaseSeconds, err := strconv.ParseInt(leaseStr, 10, 64)
|
|
if err != nil {
|
|
http.Error(w, fmt.Sprintf("error in hub.lease_seconds format %q: %s", leaseSeconds, err), 400)
|
|
return
|
|
}
|
|
err = h.Backend.FeedSetLeaseSeconds(feed, leaseSeconds)
|
|
if err != nil {
|
|
http.Error(w, fmt.Sprintf("error in while setting hub.lease_seconds: %s", err), 400)
|
|
return
|
|
}
|
|
}
|
|
|
|
verify := values.Get("hub.challenge")
|
|
fmt.Fprint(w, verify)
|
|
|
|
return
|
|
}
|
|
|
|
if r.Method != http.MethodPost {
|
|
http.Error(w, "Method not allowed", 405)
|
|
return
|
|
}
|
|
|
|
// find secret
|
|
secret := h.Backend.GetSecret(feed)
|
|
if secret == "" {
|
|
log.Printf("missing secret for feed %d\n", feed)
|
|
http.Error(w, "Unknown", 400)
|
|
return
|
|
}
|
|
|
|
feedContent, err := ioutil.ReadAll(r.Body)
|
|
|
|
// match signature
|
|
sig := r.Header.Get("X-Hub-Signature")
|
|
if sig != "" {
|
|
if err := isHubSignatureValid(sig, feedContent, secret); err != nil {
|
|
http.Error(w, fmt.Sprintf("Error in signature: %s", err), 400)
|
|
return
|
|
}
|
|
}
|
|
|
|
ct := r.Header.Get("Content-Type")
|
|
err = h.Backend.UpdateFeed(feed, ct, bytes.NewBuffer(feedContent))
|
|
if err != nil {
|
|
http.Error(w, fmt.Sprintf("Unknown format of body: %s (%s)", ct, err), 400)
|
|
return
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
func isHubSignatureValid(sig string, feedContent []byte, secret string) error {
|
|
parts := strings.Split(sig, "=")
|
|
|
|
if len(parts) != 2 {
|
|
return fmt.Errorf("signature format is not like sha1=signature")
|
|
}
|
|
|
|
if parts[0] != "sha1" {
|
|
return fmt.Errorf("signature format is not like sha1=signature")
|
|
}
|
|
|
|
// verification
|
|
mac := hmac.New(sha1.New, []byte(secret))
|
|
mac.Write(feedContent)
|
|
signature := mac.Sum(nil)
|
|
|
|
if fmt.Sprintf("%x", signature) != parts[1] {
|
|
return fmt.Errorf("signature does not match feed %s %s", signature, parts[1])
|
|
}
|
|
|
|
return nil
|
|
}
|