feat: Support accept follow

activitypub/accept.go

@@ -0,0 +1,27 @@
+package activitypub
+
+import (
+	"log/slog"
+
+	"github.com/pichuchen/hatsuaki/datastore/actor"
+)
+
+func SendAccept(senderActor *actor.Actor, recevierActorID string, followActiveObjectID string) {
+	slog.Info("SendAccept", "sender", senderActor.GetUsername(), "receiver", recevierActorID, "object", followActiveObjectID)
+
+	acceptActive := map[string]interface{}{
+		"@context": "https://www.w3.org/ns/activitystreams",
+		"type":     "Accept",
+		"actor":    senderActor.GetFullID(),
+		"object":   followActiveObjectID,
+	}
+
+	// the object is transient, in which case the id MAY be omitted
+	// acceptActive["id"] = senderActor.GetFullID() + "/outbox/" + time.Now().String()
+
+	// append to the sender's outbox
+	// senderActor.AppendOutboxObject(acceptActive["id"].(string))
+
+	SendActivity(senderActor.GetUsername(), recevierActorID, acceptActive)
+
+}

activitypub/inbox.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log/slog"
 	"net/http"
+	"time"
 
 	"github.com/pichuchen/hatsuaki/datastore/actor"
 	"github.com/pichuchen/hatsuaki/datastore/config"
@@ -155,19 +156,56 @@ func PostActorInbox(w http.ResponseWriter, r *http.Request, a *actor.Actor) {
 }
 
 func PostActorInboxFollow(w http.ResponseWriter, r *http.Request, a *actor.Actor, requestMap map[string]interface{}) {
-	slog.Info("activitypub.PostActorInboxFollow", "info", "follow")
+	slog.Info("activitypub.PostActorInboxFollow", "info", "follow", "requestMap.object", requestMap["object"])
+	followID := requestMap["id"].(string)
+
+	// 這邊的 objectID 是我們自己站上的 actor 的 ID
+	var objectID string
+	switch o := requestMap["object"].(type) {
+	case string:
+		objectID = o
+	case map[string]interface{}:
+		objectID = o["id"].(string)
+	default:
+		slog.Warn("activitypub.PostActorInboxFollow", "error", "object type error")
+		w.WriteHeader(http.StatusBadRequest)
+		json.NewEncoder(w).Encode(map[string]string{"error": "bad request"})
+		return
+	}
 
-	// 這邊是在 ActivityPub 中的必要 (MUST) 欄位
-	w.Header().Set("Content-Type", "application/activity+json")
+	// 檢查 objectID 是否等同於我們自己站上的 actor 的 ID
+	if objectID != a.GetFullID() {
+		slog.Warn("activitypub.PostActorInboxFollow", "error", "objectID not match")
+		w.WriteHeader(http.StatusBadRequest)
+		json.NewEncoder(w).Encode(map[string]string{"error": "bad request"})
+		return
+	}
 
-	// 這邊是在 ActivityPub 中的必要 (MUST) 欄位
-	m := map[string]interface{}{}
-	m["id"] = "https://" + config.GetDomain() + "/.activitypub/actor/" + a.GetUsername() + "/inbox"
+	// 這邊的 actorID 是提出 follow 請求的 actor 的 ID
+	var actorID string
+	switch a := requestMap["actor"].(type) {
+	case string:
+		actorID = a
+	case map[string]interface{}:
+		actorID = a["id"].(string)
+	default:
+		slog.Warn("activitypub.PostActorInboxFollow", "error", "actor type error")
+		w.WriteHeader(http.StatusBadRequest)
+		json.NewEncoder(w).Encode(map[string]string{"error": "bad request"})
+		return
+	}
 
-	// 這邊是在 ActivityPub 中的必要 (MUST) 欄位
-	m["type"] = "OrderedCollection"
+	slog.Info("activitypub.PostActorInboxFollow", "followID", followID)
+
+	if config.GetEnableAutoAcceptFollow() {
+		// 這邊暫停五秒是讓 Debug Log 看起來比較清楚
+		time.Sleep(5 * time.Second)
+		slog.Info("activitypub.PostActorInboxFollow", "info", "auto accept follow")
+		SendAccept(a, actorID, followID)
+		a.AppendFollowerID(actorID)
+		actor.SaveActor("./actor.json")
+	}
 
-	json.NewEncoder(w).Encode(m)
 }
 
 func PostSharedInbox(w http.ResponseWriter, r *http.Request) {

activitypub/send.go

@@ -0,0 +1,178 @@
+package activitypub
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/pichuchen/hatsuaki/activitypub/signature"
+	"github.com/pichuchen/hatsuaki/datastore/actor"
+)
+
+func SendActivity(senderUsername string, recevierActorID string, activity map[string]interface{}) {
+	// 這邊應該要把 activity 送到 recevierActorID 的 inbox
+
+	// 首先要先取的對方的 inbox 位置
+	inbox, err := GetInboxByActorID(recevierActorID, false)
+	if err != nil {
+		slog.Error("GetInboxByActorID failed", "error", err)
+		return
+	}
+
+	// 然後送出 activity
+	activityByte, err := json.Marshal(activity)
+	if err != nil {
+		slog.Error("Marshal activity failed", "error", err)
+		return
+	}
+
+	req, err := http.NewRequest("POST", inbox, strings.NewReader(string(activityByte)))
+	if err != nil {
+		slog.Error("Create request failed", "error", err)
+		return
+	}
+
+	req.Header.Set("Content-Type", "application/activity+json")
+	req.Header.Set("Accept", "application/activity+json, application/ld+json")
+
+	// Add Date
+	gmtTimeLoc := time.FixedZone("GMT", 0)
+	s := time.Now().In(gmtTimeLoc).Format(http.TimeFormat)
+	req.Header.Add("Date", s)
+
+	// Add Host
+	req.Header.Add("Host", req.URL.Host)
+
+	// Add Signature
+	senderActor, err := actor.FindActorByUsername(senderUsername)
+	if err != nil {
+		slog.Error("SendActivity", "error", err)
+		return
+	}
+	keyID := fmt.Sprintf("%s#main-key", senderActor.GetFullID())
+	signature.Signature(senderActor.GetPrivateKey(), keyID, req)
+
+	slog.Info("SendActivity", "activity", string(activityByte))
+
+	req.Body = io.NopCloser(strings.NewReader(string(activityByte)))
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		slog.Error("SendActivity failed", "error", err)
+		return
+	}
+	defer resp.Body.Close()
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		slog.Error("Read response body failed", "Error", err)
+		return
+	}
+
+	slog.Info("SendActivity response", "body", string(respBody))
+
+	if resp.StatusCode != http.StatusOK {
+		slog.Error("SendActivity failed", "status code", resp.StatusCode)
+		return
+	}
+
+	slog.Info("SendActivity success", "activity", activity, "receiver", recevierActorID)
+
+}
+
+// GetInboxByActorID 會回傳 actor 的 inbox 位置，
+// 如果 sign 是 true 的話，則需要對回傳的位置進行簽章
+func GetInboxByActorID(actorID string, sign bool) (string, error) {
+	reqURL := actorID
+	req, err := http.NewRequest("GET", reqURL, nil)
+	if err != nil {
+		return "", err
+	}
+
+	req.Header.Set("Accept", "application/activity+json, application/ld+json")
+	// Add Date
+	gmtTimeLoc := time.FixedZone("GMT", 0)
+	s := time.Now().In(gmtTimeLoc).Format(http.TimeFormat)
+	req.Header.Add("Date", s)
+
+	// Add Host
+	req.Header.Add("Host", req.URL.Host)
+
+	// Add Signature
+	if sign {
+		instanceActor, err := actor.FindActorByUsername("instance.actor")
+		if err != nil {
+			slog.Error("GetInboxByActorID", "error", err)
+			return "", err
+		}
+		keyID := fmt.Sprintf("%s#main-key", instanceActor.GetFullID())
+		signature.Signature(instanceActor.GetPrivateKey(), keyID, req)
+	}
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		slog.Error("GetInboxByActorID", "error", err)
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("status code: %d", resp.StatusCode)
+	}
+
+	respByte, err := io.ReadAll(resp.Body)
+	if err != nil {
+		slog.Error("Read response body failed", "Error", err)
+		return "", err
+	}
+
+	respMap := map[string]interface{}{}
+	err = json.Unmarshal(respByte, &respMap)
+	if err != nil {
+		slog.Error("Unmarshal response body failed", "Error", err, "body", string(respByte))
+		return "", err
+	}
+
+	slog.Info("Get actor success", "actor", actorID, "Response", respMap)
+
+	errorStr, ok := respMap["error"]
+	if ok {
+		if strings.Contains(errorStr.(string), "Request not signed") {
+			slog.Info("request not signed, retry with signature")
+			return GetInboxByActorID(actorID, true)
+		}
+		slog.Error("Get actor failed", "actor", actorID, "Error", errorStr)
+		return "", errors.New("get actor failed")
+	}
+
+	// 如果有 sharedInbox 的話，就優先回傳 sharedInbox
+	sharedInbox, ok := respMap["endpoints"].(map[string]interface{})["sharedInbox"]
+	if ok {
+		sharedInboxStr, ok := sharedInbox.(string)
+		if ok {
+			return sharedInboxStr, nil
+		}
+	}
+
+	inbox, ok := respMap["inbox"]
+	if !ok {
+		slog.Error("No inbox in actor", "actor", actorID)
+		return "", errors.New("no inbox in actor")
+	}
+
+	inboxStr, ok := inbox.(string)
+	if !ok {
+		slog.Error("Inbox is not string", "inbox", inbox)
+		return "", errors.New("inbox is not string")
+	}
+
+	return inboxStr, nil
+
+}

datastore/actor/main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log/slog"
 	"os"
+	"strings"
 	"sync"
 
 	"github.com/pichuchen/hatsuaki/activitypub/signature"
@@ -91,6 +92,16 @@ func FindActorByUsername(username string) (actor *Actor, err error) {
 	return nil, fmt.Errorf("actor not found")
 }
 
+func FindActorByFullID(fullID string) (actor *Actor, err error) {
+	slog.Info("actor.FindActorByFullID", "fullID", fullID)
+	prefix := "https://" + config.GetDomain() + "/.activitypub/actor/"
+	if !strings.HasPrefix(fullID, prefix) {
+		return nil, fmt.Errorf("invalid fullID")
+	}
+	username := fullID[len("https://"+config.GetDomain()+"/.activitypub/actor/"):]
+	return FindActorByUsername(username)
+}
+
 func (a *Actor) GetUsername() string {
 	return (*a)["username"].(string)
 }
@@ -159,3 +170,52 @@ func VerifyPassword(username, password string) error {
 	}
 	return nil
 }
+
+func (a *Actor) AppendFollowerID(followerID string) {
+	ids := a.GetFollowerIDs()
+	ids = append(ids, followerID)
+	(*a)["followers"] = ids
+}
+
+func (a *Actor) GetFollowerIDs() []string {
+	n, ok := (*a)["followers"]
+	if !ok {
+		return []string{}
+	}
+	switch v := n.(type) {
+	case []string:
+		return v
+	case []interface{}:
+		ids := make([]string, len(v))
+		for i, val := range v {
+			ids[i] = val.(string)
+		}
+		return ids
+	}
+	return []string{}
+}
+
+func (a *Actor) AppendFollowingID(followingID string) {
+	ids := a.GetFollowingIDs()
+	ids = append(ids, followingID)
+	(*a)["following"] = ids
+}
+
+func (a *Actor) GetFollowingIDs() []string {
+	n, ok := (*a)["following"]
+	if !ok {
+		return []string{}
+	}
+	switch v := n.(type) {
+	case []string:
+		return v
+	case []interface{}:
+		ids := make([]string, len(v))
+		for i, val := range v {
+			ids[i] = val.(string)
+		}
+		return ids
+	}
+	return []string{}
+
+}

datastore/config/main.go

@@ -9,6 +9,8 @@ type Config struct {
 	// Domain 是這個服務的域名，舉例來說 @[email protected] 的 domain 就是 example.com
 	Domain         string `json:"domain"`
 	LoginJWTSecret string `json:"login_jwt_secret"`
+	// The Accept or Reject MAY be generated automatically - https://www.w3.org/TR/activitypub/#follow-activity-inbox
+	EnableAutoAcceptFollow bool `json:"enable_auto_accept_follow"`
 }
 
 var runningConfig Config
@@ -25,6 +27,14 @@ func SetLoginJWTSecret(secret string) {
 	runningConfig.LoginJWTSecret = secret
 }
 
+func GetEnableAutoAcceptFollow() bool {
+	return runningConfig.EnableAutoAcceptFollow
+}
+
+func SetEnableAutoAcceptFollow(b bool) {
+	runningConfig.EnableAutoAcceptFollow = b
+}
+
 func LoadConfig(filepath string) error {
 	f, err := os.ReadFile(filepath)
 	if err != nil {

serverlet/main.go

@@ -48,6 +48,7 @@ func main() {
 			slog.Error("main", "error", err)
 		}
 		config.SetLoginJWTSecret(base64.StdEncoding.EncodeToString(key))
+		config.SetEnableAutoAcceptFollow(true)
 		err = config.SaveConfig("./config.json")
 		if err != nil {
 			slog.Error("main", "error", err)