well-goknown/vendor/github.com/fiatjaf/khatru/handlers.go

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package khatru
import (
"context"
"crypto/rand"
"crypto/sha256"
"encoding/hex"
"errors"
"net/http"
"strings"
"sync"
"time"
"github.com/fasthttp/websocket"
"github.com/nbd-wtf/go-nostr"
"github.com/nbd-wtf/go-nostr/nip42"
"github.com/rs/cors"
)
// ServeHTTP implements http.Handler interface.
func (rl *Relay) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if rl.ServiceURL == "" {
rl.ServiceURL = getServiceBaseURL(r)
}
if r.Header.Get("Upgrade") == "websocket" {
rl.HandleWebsocket(w, r)
} else if r.Header.Get("Accept") == "application/nostr+json" {
cors.AllowAll().Handler(http.HandlerFunc(rl.HandleNIP11)).ServeHTTP(w, r)
} else if r.Header.Get("Content-Type") == "application/nostr+json+rpc" {
cors.AllowAll().Handler(http.HandlerFunc(rl.HandleNIP86)).ServeHTTP(w, r)
} else {
rl.serveMux.ServeHTTP(w, r)
}
}
func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
for _, reject := range rl.RejectConnection {
if reject(r) {
w.WriteHeader(429) // Too many requests
return
}
}
conn, err := rl.upgrader.Upgrade(w, r, nil)
if err != nil {
rl.Log.Printf("failed to upgrade websocket: %v\n", err)
return
}
ticker := time.NewTicker(rl.PingPeriod)
// NIP-42 challenge
challenge := make([]byte, 8)
rand.Read(challenge)
ws := &WebSocket{
conn: conn,
Request: r,
Challenge: hex.EncodeToString(challenge),
}
rl.clientsMutex.Lock()
rl.clients[ws] = make([]listenerSpec, 0, 2)
rl.clientsMutex.Unlock()
ctx, cancel := context.WithCancel(
context.WithValue(
context.Background(),
wsKey, ws,
),
)
kill := func() {
for _, ondisconnect := range rl.OnDisconnect {
ondisconnect(ctx)
}
ticker.Stop()
cancel()
conn.Close()
rl.removeClientAndListeners(ws)
}
go func() {
defer kill()
conn.SetReadLimit(rl.MaxMessageSize)
conn.SetReadDeadline(time.Now().Add(rl.PongWait))
conn.SetPongHandler(func(string) error {
conn.SetReadDeadline(time.Now().Add(rl.PongWait))
return nil
})
for _, onconnect := range rl.OnConnect {
onconnect(ctx)
}
for {
typ, message, err := conn.ReadMessage()
if err != nil {
if websocket.IsUnexpectedCloseError(
err,
websocket.CloseNormalClosure, // 1000
websocket.CloseGoingAway, // 1001
websocket.CloseNoStatusReceived, // 1005
websocket.CloseAbnormalClosure, // 1006
4537, // some client seems to send many of these
) {
rl.Log.Printf("unexpected close error from %s: %v\n", r.Header.Get("X-Forwarded-For"), err)
}
return
}
if typ == websocket.PingMessage {
ws.WriteMessage(websocket.PongMessage, nil)
continue
}
go func(message []byte) {
envelope := nostr.ParseMessage(message)
if envelope == nil {
// stop silently
return
}
switch env := envelope.(type) {
case *nostr.EventEnvelope:
// check id
hash := sha256.Sum256(env.Event.Serialize())
id := hex.EncodeToString(hash[:])
if id != env.Event.ID {
ws.WriteJSON(nostr.OKEnvelope{EventID: env.Event.ID, OK: false, Reason: "invalid: id is computed incorrectly"})
return
}
// check signature
if ok, err := env.Event.CheckSignature(); err != nil {
ws.WriteJSON(nostr.OKEnvelope{EventID: env.Event.ID, OK: false, Reason: "error: failed to verify signature"})
return
} else if !ok {
ws.WriteJSON(nostr.OKEnvelope{EventID: env.Event.ID, OK: false, Reason: "invalid: signature is invalid"})
return
}
// check NIP-70 protected
for _, v := range env.Event.Tags {
if len(v) == 1 && v[0] == "-" {
msg := "must be published by event author"
authed := GetAuthed(ctx)
if authed == "" {
RequestAuth(ctx)
ws.WriteJSON(nostr.OKEnvelope{
EventID: env.Event.ID,
OK: false,
Reason: "auth-required: " + msg,
})
return
}
if authed != env.Event.PubKey {
ws.WriteJSON(nostr.OKEnvelope{
EventID: env.Event.ID,
OK: false,
Reason: "blocked: " + msg,
})
return
}
}
}
srl := rl
if rl.getSubRelayFromEvent != nil {
srl = rl.getSubRelayFromEvent(&env.Event)
}
var ok bool
var writeErr error
var skipBroadcast bool
if env.Event.Kind == 5 {
// this always returns "blocked: " whenever it returns an error
writeErr = srl.handleDeleteRequest(ctx, &env.Event)
} else {
// this will also always return a prefixed reason
skipBroadcast, writeErr = srl.AddEvent(ctx, &env.Event)
}
var reason string
if writeErr == nil {
ok = true
for _, ovw := range srl.OverwriteResponseEvent {
ovw(ctx, &env.Event)
}
if !skipBroadcast {
srl.notifyListeners(&env.Event)
}
} else {
reason = writeErr.Error()
if strings.HasPrefix(reason, "auth-required:") {
RequestAuth(ctx)
}
}
ws.WriteJSON(nostr.OKEnvelope{EventID: env.Event.ID, OK: ok, Reason: reason})
case *nostr.CountEnvelope:
if rl.CountEvents == nil {
ws.WriteJSON(nostr.ClosedEnvelope{SubscriptionID: env.SubscriptionID, Reason: "unsupported: this relay does not support NIP-45"})
return
}
var total int64
for _, filter := range env.Filters {
srl := rl
if rl.getSubRelayFromFilter != nil {
srl = rl.getSubRelayFromFilter(filter)
}
total += srl.handleCountRequest(ctx, ws, filter)
}
ws.WriteJSON(nostr.CountEnvelope{SubscriptionID: env.SubscriptionID, Count: &total})
case *nostr.ReqEnvelope:
eose := sync.WaitGroup{}
eose.Add(len(env.Filters))
// a context just for the "stored events" request handler
reqCtx, cancelReqCtx := context.WithCancelCause(ctx)
// expose subscription id in the context
reqCtx = context.WithValue(reqCtx, subscriptionIdKey, env.SubscriptionID)
// handle each filter separately -- dispatching events as they're loaded from databases
for _, filter := range env.Filters {
srl := rl
if rl.getSubRelayFromFilter != nil {
srl = rl.getSubRelayFromFilter(filter)
}
err := srl.handleRequest(reqCtx, env.SubscriptionID, &eose, ws, filter)
if err != nil {
// fail everything if any filter is rejected
reason := err.Error()
if strings.HasPrefix(reason, "auth-required:") {
RequestAuth(ctx)
}
ws.WriteJSON(nostr.ClosedEnvelope{SubscriptionID: env.SubscriptionID, Reason: reason})
cancelReqCtx(errors.New("filter rejected"))
return
} else {
rl.addListener(ws, env.SubscriptionID, srl, filter, cancelReqCtx)
}
}
go func() {
// when all events have been loaded from databases and dispatched
// we can cancel the context and fire the EOSE message
eose.Wait()
cancelReqCtx(nil)
ws.WriteJSON(nostr.EOSEEnvelope(env.SubscriptionID))
}()
case *nostr.CloseEnvelope:
id := string(*env)
rl.removeListenerId(ws, id)
case *nostr.AuthEnvelope:
wsBaseUrl := strings.Replace(rl.ServiceURL, "http", "ws", 1)
if pubkey, ok := nip42.ValidateAuthEvent(&env.Event, ws.Challenge, wsBaseUrl); ok {
ws.AuthedPublicKey = pubkey
ws.authLock.Lock()
if ws.Authed != nil {
close(ws.Authed)
ws.Authed = nil
}
ws.authLock.Unlock()
ws.WriteJSON(nostr.OKEnvelope{EventID: env.Event.ID, OK: true})
} else {
ws.WriteJSON(nostr.OKEnvelope{EventID: env.Event.ID, OK: false, Reason: "error: failed to authenticate"})
}
}
}(message)
}
}()
go func() {
defer kill()
for {
select {
case <-ctx.Done():
return
case <-ticker.C:
err := ws.WriteMessage(websocket.PingMessage, nil)
if err != nil {
if !strings.HasSuffix(err.Error(), "use of closed network connection") {
rl.Log.Printf("error writing ping: %v; closing websocket\n", err)
}
return
}
}
}
}()
}