Merge pull request #439 from writeas/support-authorized-fetch

Fix following from Mastodon with Authorized Fetch enabled

activitypub.go

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2018-2020 A Bunch Tell LLC.
+ * Copyright © 2018-2021 A Bunch Tell LLC.
  *
  * This file is part of WriteFreely.
  *
@@ -21,6 +21,7 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"net/url"
+	"path/filepath"
 	"strconv"
 	"time"
 
@@ -41,6 +42,19 @@ const (
 	apCacheTime = time.Minute
 )
 
+var instanceColl *Collection
+
+func initActivityPub(app *App) {
+	ur, _ := url.Parse(app.cfg.App.Host)
+	instanceColl = &Collection{
+		ID:       0,
+		Alias:    ur.Host,
+		Title:    ur.Host,
+		db:       app.db,
+		hostName: app.cfg.App.Host,
+	}
+}
+
 type RemoteUser struct {
 	ID          int64
 	ActorID     string
@@ -76,12 +90,17 @@ func handleFetchCollectionActivities(app *App, w http.ResponseWriter, r *http.Re
 
 	vars := mux.Vars(r)
 	alias := vars["alias"]
+	if alias == "" {
+		alias = filepath.Base(r.RequestURI)
+	}
 
 	// TODO: enforce visibility
 	// Get base Collection data
 	var c *Collection
 	var err error
-	if app.cfg.App.SingleUser {
+	if alias == r.Host {
+		c = instanceColl
+	} else if app.cfg.App.SingleUser {
 		c, err = app.db.GetCollectionByID(1)
 	} else {
 		c, err = app.db.GetCollection(alias)
@@ -89,6 +108,9 @@ func handleFetchCollectionActivities(app *App, w http.ResponseWriter, r *http.Re
 	if err != nil {
 		return err
 	}
+	c.hostName = app.cfg.App.Host
+
+	if !c.IsInstanceColl() {
 		silenced, err := app.db.IsUserSilenced(c.OwnerID)
 		if err != nil {
 			log.Error("fetch collection activities: %v", err)
@@ -97,7 +119,7 @@ func handleFetchCollectionActivities(app *App, w http.ResponseWriter, r *http.Re
 		if silenced {
 			return ErrCollectionNotFound
 		}
-	c.hostName = app.cfg.App.Host
+	}
 
 	p := c.PersonObject()
 
@@ -546,6 +568,22 @@ func resolveIRI(hostName, url string) ([]byte, error) {
 	r.Header.Add("Accept", "application/activity+json")
 	r.Header.Set("User-Agent", ServerUserAgent(hostName))
 
+	p := instanceColl.PersonObject()
+	h := sha256.New()
+	h.Write([]byte{})
+	r.Header.Add("Digest", "SHA-256="+base64.StdEncoding.EncodeToString(h.Sum(nil)))
+
+	// Sign using the 'Signature' header
+	privKey, err := activitypub.DecodePrivateKey(p.GetPrivKey())
+	if err != nil {
+		return nil, err
+	}
+	signer := httpsig.NewSigner(p.PublicKey.ID, privKey, httpsig.RSASHA256, []string{"(request-target)", "date", "host", "digest"})
+	err = signer.SignSigHeader(r)
+	if err != nil {
+		log.Error("Can't sign: %v", err)
+	}
+
 	if debugging {
 		dump, err := httputil.DumpRequestOut(r, true)
 		if err != nil {

app.go

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2018-2019 A Bunch Tell LLC.
+ * Copyright © 2018-2021 A Bunch Tell LLC.
  *
  * This file is part of WriteFreely.
  *
@@ -389,6 +389,8 @@ func Initialize(apper Apper, debug bool) (*App, error) {
 		return nil, fmt.Errorf("connect to DB: %s", err)
 	}
 
+	initActivityPub(apper.App())
+
 	// Handle local timeline, if enabled
 	if apper.App().cfg.App.LocalTimeline {
 		log.Info("Initializing local timeline...")

collections.go

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2018-2020 A Bunch Tell LLC.
+ * Copyright © 2018-2021 A Bunch Tell LLC.
  *
  * This file is part of WriteFreely.
  *
@@ -180,6 +180,11 @@ func (c *Collection) NewFormat() *CollectionFormat {
 	return cf
 }
 
+func (c *Collection) IsInstanceColl() bool {
+	ur, _ := url.Parse(c.hostName)
+	return c.Alias == ur.Host
+}
+
 func (c *Collection) IsUnlisted() bool {
 	return c.Visibility == 0
 }

routes.go

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2018-2019 A Bunch Tell LLC.
+ * Copyright © 2018-2021 A Bunch Tell LLC.
  *
  * This file is part of WriteFreely.
  *
@@ -12,6 +12,7 @@ package writefreely
 
 import (
 	"net/http"
+	"net/url"
 	"path/filepath"
 	"strings"
 
@@ -125,9 +126,13 @@ func InitRoutes(apper Apper, r *mux.Router) *mux.Router {
 
 	write.HandleFunc("/api/markdown", handler.All(handleRenderMarkdown)).Methods("POST")
 
+	instanceURL, _ := url.Parse(apper.App().Config().App.Host)
+	host := instanceURL.Host
+
 	// Handle collections
 	write.HandleFunc("/api/collections", handler.All(newCollection)).Methods("POST")
 	apiColls := write.PathPrefix("/api/collections/").Subrouter()
+	apiColls.HandleFunc("/"+host, handler.AllReader(fetchCollection)).Methods("GET")
 	apiColls.HandleFunc("/{alias:[0-9a-zA-Z\\-]+}", handler.AllReader(fetchCollection)).Methods("GET")
 	apiColls.HandleFunc("/{alias:[0-9a-zA-Z\\-]+}", handler.All(existingCollection)).Methods("POST", "DELETE")
 	apiColls.HandleFunc("/{alias}/posts", handler.AllReader(fetchCollectionPosts)).Methods("GET")

webfinger.go

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2018-2020 A Bunch Tell LLC.
+ * Copyright © 2018-2021 A Bunch Tell LLC.
  *
  * This file is part of WriteFreely.
  *
@@ -32,7 +32,9 @@ var wfUserNotFoundErr = impart.HTTPError{http.StatusNotFound, "User not found."}
 func (wfr wfResolver) FindUser(username string, host, requestHost string, r []webfinger.Rel) (*webfinger.Resource, error) {
 	var c *Collection
 	var err error
-	if wfr.cfg.App.SingleUser {
+	if username == host {
+		c = instanceColl
+	} else if wfr.cfg.App.SingleUser {
 		c, err = wfr.db.GetCollectionByID(1)
 	} else {
 		c, err = wfr.db.GetCollection(username)
@@ -41,6 +43,9 @@ func (wfr wfResolver) FindUser(username string, host, requestHost string, r []we
 		log.Error("Unable to get blog: %v", err)
 		return nil, err
 	}
+	c.hostName = wfr.cfg.App.Host
+
+	if !c.IsInstanceColl() {
 		silenced, err := wfr.db.IsUserSilenced(c.OwnerID)
 		if err != nil {
 			log.Error("webfinger find user: check is silenced: %v", err)
@@ -49,7 +54,7 @@ func (wfr wfResolver) FindUser(username string, host, requestHost string, r []we
 		if silenced {
 			return nil, wfUserNotFoundErr
 		}
-	c.hostName = wfr.cfg.App.Host
+	}
 	if wfr.cfg.App.SingleUser {
 		// Ensure handle matches user-chosen one on single-user blogs
 		if username != c.Alias {