OverwriteRelayInformation

README.md

@@ -34,7 +34,7 @@ func main() {
 	relay.Info.Name = "my relay"
 	relay.Info.PubKey = "79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798"
 	relay.Info.Description = "this is my custom relay"
-	relay.Info.IconURL = "https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fliquipedia.net%2Fcommons%2Fimages%2F3%2F35%2FSCProbe.jpg&f=1&nofb=1&ipt=0cbbfef25bce41da63d910e86c3c343e6c3b9d63194ca9755351bb7c2efa3359&ipo=images"
+	relay.Info.Icon = "https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fliquipedia.net%2Fcommons%2Fimages%2F3%2F35%2FSCProbe.jpg&f=1&nofb=1&ipt=0cbbfef25bce41da63d910e86c3c343e6c3b9d63194ca9755351bb7c2efa3359&ipo=images"
 
 	// you must bring your own storage scheme -- if you want to have any
 	store := make(map[string]*nostr.Event, 120)

handlers.go

@@ -14,6 +14,7 @@ import (
 	"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.
@@ -21,7 +22,7 @@ func (rl *Relay) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if r.Header.Get("Upgrade") == "websocket" {
 		rl.HandleWebsocket(w, r)
 	} else if r.Header.Get("Accept") == "application/nostr+json" {
-		rl.HandleNIP11(w, r)
+		cors.AllowAll().Handler(http.HandlerFunc(rl.HandleNIP11)).ServeHTTP(w, r)
 	} else {
 		rl.serveMux.ServeHTTP(w, r)
 	}
@@ -48,6 +49,8 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 		WaitingForAuth: make(chan struct{}),
 	}
 
+	ctx = context.WithValue(ctx, WS_KEY, ws)
+
 	// reader
 	go func() {
 		defer func() {
@@ -75,6 +78,7 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 			if err != nil {
 				if websocket.IsUnexpectedCloseError(
 					err,
+					websocket.CloseNormalClosure,    // 1000
 					websocket.CloseGoingAway,        // 1001
 					websocket.CloseNoStatusReceived, // 1005
 					websocket.CloseAbnormalClosure,  // 1006
@@ -115,14 +119,15 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 						return
 					}
 
-					// check serialization
-					serialized := evt.Serialize()
+					// check id
+					hash := sha256.Sum256(evt.Serialize())
+					id := hex.EncodeToString(hash[:])
+					if id != evt.ID {
+						ws.WriteJSON(nostr.OKEnvelope{EventID: evt.ID, OK: false, Reason: "invalid: id is computed incorrectly"})
+						return
+					}
 
-					// assign ID
-					hash := sha256.Sum256(serialized)
-					evt.ID = hex.EncodeToString(hash[:])
-
-					// check signature (requires the ID to be set)
+					// check signature
 					if ok, err := evt.CheckSignature(); err != nil {
 						ws.WriteJSON(nostr.OKEnvelope{EventID: evt.ID, OK: false, Reason: "error: failed to verify signature"})
 						return
@@ -251,5 +256,11 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 
 func (rl *Relay) HandleNIP11(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/nostr+json")
-	json.NewEncoder(w).Encode(rl.Info)
+
+	info := *rl.Info
+	for _, ovw := range rl.OverwriteRelayInformation {
+		info = ovw(r.Context(), r, info)
+	}
+
+	json.NewEncoder(w).Encode(info)
 }

policies/events.go

@@ -1,15 +1,37 @@
-package plugins
+package policies
 
 import (
 	"context"
 
 	"github.com/nbd-wtf/go-nostr"
+	"golang.org/x/exp/slices"
 )
 
 // PreventTooManyIndexableTags returns a function that can be used as a RejectFilter that will reject
 // events with more indexable (single-character) tags than the specified number.
-func PreventTooManyIndexableTags(max int) func(context.Context, *nostr.Event) (bool, string) {
+//
+// If ignoreKinds is given this restriction will not apply to these kinds (useful for allowing a bigger).
+// If onlyKinds is given then all other kinds will be ignored.
+func PreventTooManyIndexableTags(max int, ignoreKinds []int, onlyKinds []int) func(context.Context, *nostr.Event) (bool, string) {
+	ignore := func(kind int) bool { return false }
+	if len(ignoreKinds) > 0 {
+		ignore = func(kind int) bool {
+			_, isIgnored := slices.BinarySearch(ignoreKinds, kind)
+			return isIgnored
+		}
+	}
+	if len(onlyKinds) > 0 {
+		ignore = func(kind int) bool {
+			_, isApplicable := slices.BinarySearch(onlyKinds, kind)
+			return !isApplicable
+		}
+	}
+
 	return func(ctx context.Context, event *nostr.Event) (reject bool, msg string) {
+		if ignore(event.Kind) {
+			return false, ""
+		}
+
 		ntags := 0
 		for _, tag := range event.Tags {
 			if len(tag) > 0 && len(tag[0]) == 1 {
@@ -42,9 +64,7 @@ func PreventLargeTags(maxTagValueLen int) func(context.Context, *nostr.Event) (b
 func RestrictToSpecifiedKinds(kinds ...uint16) func(context.Context, *nostr.Event) (bool, string) {
 	max := 0
 	min := 0
-	allowed := make(map[uint16]struct{}, len(kinds))
 	for _, kind := range kinds {
-		allowed[kind] = struct{}{}
 		if int(kind) > max {
 			max = int(kind)
 		}
@@ -64,7 +84,7 @@ func RestrictToSpecifiedKinds(kinds ...uint16) func(context.Context, *nostr.Even
 		}
 
 		// hopefully this map of uint16s is very fast
-		if _, allowed := allowed[uint16(event.Kind)]; allowed {
+		if _, allowed := slices.BinarySearch(kinds, uint16(event.Kind)); allowed {
 			return false, ""
 		}
 		return true, "event kind not allowed"

policies/filters.go

@@ -1,4 +1,4 @@
-package plugins
+package policies
 
 import (
 	"context"
@@ -7,6 +7,7 @@ import (
 	"golang.org/x/exp/slices"
 )
 
+// NoComplexFilters disallows filters with more than 2 tags.
 func NoComplexFilters(ctx context.Context, filter nostr.Filter) (reject bool, msg string) {
 	items := len(filter.Tags) + len(filter.Kinds)
 
@@ -17,6 +18,7 @@ func NoComplexFilters(ctx context.Context, filter nostr.Filter) (reject bool, ms
 	return false, ""
 }
 
+// NoEmptyFilters disallows filters that don't have at least a tag, a kind, an author or an id.
 func NoEmptyFilters(ctx context.Context, filter nostr.Filter) (reject bool, msg string) {
 	c := len(filter.Kinds) + len(filter.IDs) + len(filter.Authors)
 	for _, tagItems := range filter.Tags {
@@ -28,6 +30,13 @@ func NoEmptyFilters(ctx context.Context, filter nostr.Filter) (reject bool, msg
 	return false, ""
 }
 
+// AntiSyncBots tries to prevent people from syncing kind:1s from this relay to else by always
+// requiring an author parameter at least.
+func AntiSyncBots(ctx context.Context, filter nostr.Filter) (reject bool, msg string) {
+	return (len(filter.Kinds) == 0 || slices.Contains(filter.Kinds, 1)) &&
+		len(filter.Authors) == 0, "an author must be specified to get their kind:1 notes"
+}
+
 func NoSearchQueries(ctx context.Context, filter nostr.Filter) (reject bool, msg string) {
 	if filter.Search != "" {
 		return true, "search is not supported"

policies/nip04.go

@@ -1,4 +1,4 @@
-package plugins
+package policies
 
 import (
 	"context"
@@ -8,7 +8,8 @@ import (
 	"golang.org/x/exp/slices"
 )
 
-func rejectKind04Snoopers(ctx context.Context, filter nostr.Filter) (bool, string) {
+// RejectKind04Snoopers prevents reading NIP-04 messages from people not involved in the conversation.
+func RejectKind04Snoopers(ctx context.Context, filter nostr.Filter) (bool, string) {
 	// prevent kind-4 events from being returned to unauthed users,
 	//   only when authentication is a thing
 	if !slices.Contains(filter.Kinds, 4) {

relay.go

@@ -18,8 +18,9 @@ func NewRelay() *Relay {
 		Log: log.New(os.Stderr, "[khatru-relay] ", log.LstdFlags),
 
 		Info: &nip11.RelayInformationDocument{
-			Software: "https://github.com/fiatjaf/khatru",
-			Version:  "n/a",
+			Software:      "https://github.com/fiatjaf/khatru",
+			Version:       "n/a",
+			SupportedNIPs: make([]int, 0),
 		},
 
 		upgrader: websocket.Upgrader{
@@ -41,20 +42,21 @@ func NewRelay() *Relay {
 type Relay struct {
 	ServiceURL string // required for nip-42
 
-	RejectEvent              []func(ctx context.Context, event *nostr.Event) (reject bool, msg string)
-	RejectFilter             []func(ctx context.Context, filter nostr.Filter) (reject bool, msg string)
-	RejectCountFilter        []func(ctx context.Context, filter nostr.Filter) (reject bool, msg string)
-	OverwriteDeletionOutcome []func(ctx context.Context, target *nostr.Event, deletion *nostr.Event) (acceptDeletion bool, msg string)
-	OverwriteResponseEvent   []func(ctx context.Context, event *nostr.Event)
-	OverwriteFilter          []func(ctx context.Context, filter *nostr.Filter)
-	OverwriteCountFilter     []func(ctx context.Context, filter *nostr.Filter)
-	StoreEvent               []func(ctx context.Context, event *nostr.Event) error
-	DeleteEvent              []func(ctx context.Context, event *nostr.Event) error
-	QueryEvents              []func(ctx context.Context, filter nostr.Filter) (chan *nostr.Event, error)
-	CountEvents              []func(ctx context.Context, filter nostr.Filter) (int64, error)
-	OnAuth                   []func(ctx context.Context, pubkey string)
-	OnConnect                []func(ctx context.Context)
-	OnEventSaved             []func(ctx context.Context, event *nostr.Event)
+	RejectEvent               []func(ctx context.Context, event *nostr.Event) (reject bool, msg string)
+	RejectFilter              []func(ctx context.Context, filter nostr.Filter) (reject bool, msg string)
+	RejectCountFilter         []func(ctx context.Context, filter nostr.Filter) (reject bool, msg string)
+	OverwriteDeletionOutcome  []func(ctx context.Context, target *nostr.Event, deletion *nostr.Event) (acceptDeletion bool, msg string)
+	OverwriteResponseEvent    []func(ctx context.Context, event *nostr.Event)
+	OverwriteFilter           []func(ctx context.Context, filter *nostr.Filter)
+	OverwriteCountFilter      []func(ctx context.Context, filter *nostr.Filter)
+	OverwriteRelayInformation []func(ctx context.Context, r *http.Request, info nip11.RelayInformationDocument) nip11.RelayInformationDocument
+	StoreEvent                []func(ctx context.Context, event *nostr.Event) error
+	DeleteEvent               []func(ctx context.Context, event *nostr.Event) error
+	QueryEvents               []func(ctx context.Context, filter nostr.Filter) (chan *nostr.Event, error)
+	CountEvents               []func(ctx context.Context, filter nostr.Filter) (int64, error)
+	OnAuth                    []func(ctx context.Context, pubkey string)
+	OnConnect                 []func(ctx context.Context)
+	OnEventSaved              []func(ctx context.Context, event *nostr.Event)
 
 	// editing info will affect
 	Info *nip11.RelayInformationDocument