rename a file I don't remember why.

* optimized return messages with more context why the policy blocks an event

README.md

@@ -128,3 +128,13 @@ Fear no more. Using the https://github.com/fiatjaf/eventstore module you get a b
 	relay.CountEvents = append(relay.CountEvents, db.CountEvents)
 	relay.DeleteEvent = append(relay.DeleteEvent, db.DeleteEvent)
 ```
+
+### But I don't want to write a bunch of custom policies!
+
+Fear no more. We have a bunch of common policies written in the `github.com/fiatjaf/khatru/policies` package and also a handpicked selection of base sane defaults, which you can apply with:
+
+```go
+	policies.ApplySaneDefaults(relay)
+```
+
+Contributions to this are very much welcomed.

adding.go

@@ -10,17 +10,17 @@ import (
 )
 
 // AddEvent sends an event through then normal add pipeline, as if it was received from a websocket.
-func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
+func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) (skipBroadcast bool, writeError error) {
 	if evt == nil {
-		return errors.New("error: event is nil")
+		return false, errors.New("error: event is nil")
 	}
 
 	for _, reject := range rl.RejectEvent {
 		if reject, msg := reject(ctx, evt); reject {
 			if msg == "" {
-				return errors.New("blocked: no reason")
+				return false, errors.New("blocked: no reason")
 			} else {
-				return errors.New(nostr.NormalizeOKMessage(msg, "blocked"))
+				return false, errors.New(nostr.NormalizeOKMessage(msg, "blocked"))
 			}
 		}
 	}
@@ -31,29 +31,53 @@ func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
 			oee(ctx, evt)
 		}
 	} else {
+		// will store
+
+		// but first check if we already have it
+		filter := nostr.Filter{IDs: []string{evt.ID}}
+		for _, query := range rl.QueryEvents {
+			ch, err := query(ctx, filter)
+			if err != nil {
+				continue
+			}
+			for range ch {
+				// if we run this it means we already have this event, so we just return a success and exit
+				return true, nil
+			}
+		}
+
+		// if it's replaceable we first delete old versions
 		if evt.Kind == 0 || evt.Kind == 3 || (10000 <= evt.Kind && evt.Kind < 20000) {
 			// replaceable event, delete before storing
+			filter := nostr.Filter{Authors: []string{evt.PubKey}, Kinds: []int{evt.Kind}}
 			for _, query := range rl.QueryEvents {
-				ch, err := query(ctx, nostr.Filter{Authors: []string{evt.PubKey}, Kinds: []int{evt.Kind}})
+				ch, err := query(ctx, filter)
 				if err != nil {
 					continue
 				}
-				if previous := <-ch; previous != nil && isOlder(previous, evt) {
-					for _, del := range rl.DeleteEvent {
-						del(ctx, previous)
+				for previous := range ch {
+					if isOlder(previous, evt) {
+						for _, del := range rl.DeleteEvent {
+							del(ctx, previous)
+						}
 					}
 				}
 			}
 		} else if 30000 <= evt.Kind && evt.Kind < 40000 {
 			// parameterized replaceable event, delete before storing
 			d := evt.Tags.GetFirst([]string{"d", ""})
-			if d != nil {
-				for _, query := range rl.QueryEvents {
-					ch, err := query(ctx, nostr.Filter{Authors: []string{evt.PubKey}, Kinds: []int{evt.Kind}, Tags: nostr.TagMap{"d": []string{d.Value()}}})
-					if err != nil {
-						continue
-					}
-					if previous := <-ch; previous != nil && isOlder(previous, evt) {
+			if d == nil {
+				return false, fmt.Errorf("invalid: missing 'd' tag on parameterized replaceable event")
+			}
+
+			filter := nostr.Filter{Authors: []string{evt.PubKey}, Kinds: []int{evt.Kind}, Tags: nostr.TagMap{"d": []string{(*d)[1]}}}
+			for _, query := range rl.QueryEvents {
+				ch, err := query(ctx, filter)
+				if err != nil {
+					continue
+				}
+				for previous := range ch {
+					if isOlder(previous, evt) {
 						for _, del := range rl.DeleteEvent {
 							del(ctx, previous)
 						}
@@ -67,9 +91,9 @@ func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
 			if saveErr := store(ctx, evt); saveErr != nil {
 				switch saveErr {
 				case eventstore.ErrDupEvent:
-					return nil
+					return true, nil
 				default:
-					return fmt.Errorf(nostr.NormalizeOKMessage(saveErr.Error(), "error"))
+					return false, fmt.Errorf(nostr.NormalizeOKMessage(saveErr.Error(), "error"))
 				}
 			}
 		}
@@ -79,5 +103,5 @@ func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
 		}
 	}
 
-	return nil
+	return false, nil
 }

deleting.go

@@ -34,7 +34,9 @@ func (rl *Relay) handleDeleteRequest(ctx context.Context, evt *nostr.Event) erro
 				if acceptDeletion {
 					// delete it
 					for _, del := range rl.DeleteEvent {
-						del(ctx, target)
+						if err := del(ctx, target); err != nil {
+							return err
+						}
 					}
 				} else {
 					// fail and stop here

go.mod

@@ -4,11 +4,10 @@ go 1.21.4
 
 require (
 	github.com/fasthttp/websocket v1.5.7
-	github.com/fiatjaf/eventstore v0.3.8
-	github.com/nbd-wtf/go-nostr v0.28.1
+	github.com/fiatjaf/eventstore v0.5.0
+	github.com/nbd-wtf/go-nostr v0.34.2
 	github.com/puzpuzpuz/xsync/v3 v3.0.2
 	github.com/rs/cors v1.7.0
-	github.com/sebest/xff v0.0.0-20210106013422-671bd2870b3a
 )
 
 require (
@@ -38,7 +37,7 @@ require (
 	github.com/google/flatbuffers v23.5.26+incompatible // indirect
 	github.com/jmoiron/sqlx v1.3.5 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
-	github.com/klauspost/compress v1.17.3 // indirect
+	github.com/klauspost/compress v1.17.8 // indirect
 	github.com/lib/pq v1.10.9 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mattn/go-sqlite3 v1.14.18 // indirect
@@ -52,6 +51,6 @@ require (
 	go.opencensus.io v0.24.0 // indirect
 	golang.org/x/exp v0.0.0-20231006140011-7918f672742d // indirect
 	golang.org/x/net v0.18.0 // indirect
-	golang.org/x/sys v0.14.0 // indirect
+	golang.org/x/sys v0.20.0 // indirect
 	google.golang.org/protobuf v1.31.0 // indirect
 )

go.sum

@@ -47,8 +47,8 @@ github.com/fasthttp/websocket v1.5.7 h1:0a6o2OfeATvtGgoMKleURhLT6JqWPg7fYfWnH4KH
 github.com/fasthttp/websocket v1.5.7/go.mod h1:bC4fxSono9czeXHQUVKxsC0sNjbm7lPJR04GDFqClfU=
 github.com/fatih/structs v1.1.0 h1:Q7juDM0QtcnhCpeyLGQKyg4TOIghuNXrkL32pHAUMxo=
 github.com/fatih/structs v1.1.0/go.mod h1:9NiDSp5zOcgEDl+j00MP/WkGVPOlPRLejGD8Ga6PJ7M=
-github.com/fiatjaf/eventstore v0.3.8 h1:q4jcN95O2CVA+wP47V25BcVSNvjfOiPPIWgPmQ6hTRk=
-github.com/fiatjaf/eventstore v0.3.8/go.mod h1:Qsm5loQICkazpsj8tQmcOK95AVkQQNF09Xx/NS/Biow=
+github.com/fiatjaf/eventstore v0.5.0 h1:s+oROGUylAJhntIAPLgLekpTtxpExNd+QhSw0tby7Es=
+github.com/fiatjaf/eventstore v0.5.0/go.mod h1:A3SgQ8hwDjZuhZ1aFT250BA70EsWsTIw0KRjm6PDh0w=
 github.com/go-sql-driver/mysql v1.6.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
 github.com/go-sql-driver/mysql v1.7.1 h1:lUIinVbN1DY0xBg0eMOzmmtGoHwWBbvnWubQUrtU8EI=
 github.com/go-sql-driver/mysql v1.7.1/go.mod h1:OXbVy3sEdcQ2Doequ6Z5BW6fXNQTmx+9S1MCJN5yJMI=
@@ -103,8 +103,8 @@ github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8Hm
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
-github.com/klauspost/compress v1.17.3 h1:qkRjuerhUU1EmXLYGkSH6EZL+vPSxIrYjLNAK4slzwA=
-github.com/klauspost/compress v1.17.3/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6KH9zAO4BDxPM=
+github.com/klauspost/compress v1.17.8 h1:YcnTYrq7MikUT7k0Yb5eceMmALQPYBW/Xltxn0NAMnU=
+github.com/klauspost/compress v1.17.8/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.10.9 h1:YXG7RB+JIjhP29X+OtkiDnYaXQwpS4JEWq7dtCCRUEw=
 github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
@@ -113,8 +113,8 @@ github.com/mailru/easyjson v0.7.7/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJ
 github.com/mattn/go-sqlite3 v1.14.6/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/mattn/go-sqlite3 v1.14.18 h1:JL0eqdCOq6DJVNPSvArO/bIV9/P7fbGrV00LZHc+5aI=
 github.com/mattn/go-sqlite3 v1.14.18/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=
-github.com/nbd-wtf/go-nostr v0.28.1 h1:XQi/lBsigBXHRm7IDBJE7SR9citCh9srgf8sA5iVW3A=
-github.com/nbd-wtf/go-nostr v0.28.1/go.mod h1:OQ8sNLFJnsj17BdqZiLSmjJBIFTfDqckEYC3utS4qoY=
+github.com/nbd-wtf/go-nostr v0.34.2 h1:9b4qZ29DhQf9xEWN8/7zfDD868r1jFbpjrR3c+BHc+E=
+github.com/nbd-wtf/go-nostr v0.34.2/go.mod h1:NZQkxl96ggbO8rvDpVjcsojJqKTPwqhP4i82O7K5DJs=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -126,8 +126,6 @@ github.com/rs/cors v1.7.0 h1:+88SsELBHx5r+hZ8TCkggzSstaWNbDvThkVK8H6f9ik=
 github.com/rs/cors v1.7.0/go.mod h1:gFx+x8UowdsKA9AchylcLynDq+nNFfI8FkUZdN/jGCU=
 github.com/savsgio/gotils v0.0.0-20230208104028-c358bd845dee h1:8Iv5m6xEo1NR1AvpV+7XmhI4r39LGNzwUL4YpMuL5vk=
 github.com/savsgio/gotils v0.0.0-20230208104028-c358bd845dee/go.mod h1:qwtSXrKuJh/zsFQ12yEE89xfCrGKK63Rr7ctU/uCo4g=
-github.com/sebest/xff v0.0.0-20210106013422-671bd2870b3a h1:iLcLb5Fwwz7g/DLK89F+uQBDeAhHhwdzB5fSlVdhGcM=
-github.com/sebest/xff v0.0.0-20210106013422-671bd2870b3a/go.mod h1:wozgYq9WEBQBaIJe4YZ0qTSFAMxmcwBhQH0fO0R34Z0=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
@@ -135,8 +133,8 @@ github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81P
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
-github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/tidwall/gjson v1.17.0 h1:/Jocvlh98kcTfpN2+JzGQWQcqrPQwDrVEMApx/M5ZwM=
 github.com/tidwall/gjson v1.17.0/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
 github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
@@ -186,8 +184,8 @@ golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20221010170243-090e33056c14/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.14.0 h1:Vz7Qs629MkJkGyHxUlRHizWJRG2j8fbQKjELVSNhy7Q=
-golang.org/x/sys v0.14.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
+golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

handlers.go

@@ -5,7 +5,6 @@ import (
 	"crypto/rand"
 	"crypto/sha256"
 	"encoding/hex"
-	"encoding/json"
 	"errors"
 	"net/http"
 	"strings"
@@ -28,12 +27,21 @@ func (rl *Relay) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		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)
@@ -161,12 +169,13 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 
 					var ok bool
 					var writeErr error
+					var skipBroadcast bool
 					if env.Event.Kind == 5 {
 						// this always returns "blocked: " whenever it returns an error
 						writeErr = rl.handleDeleteRequest(ctx, &env.Event)
 					} else {
 						// this will also always return a prefixed reason
-						writeErr = rl.AddEvent(ctx, &env.Event)
+						skipBroadcast, writeErr = rl.AddEvent(ctx, &env.Event)
 					}
 
 					var reason string
@@ -175,7 +184,9 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 						for _, ovw := range rl.OverwriteResponseEvent {
 							ovw(ctx, &env.Event)
 						}
-						notifyListeners(&env.Event)
+						if !skipBroadcast {
+							notifyListeners(&env.Event)
+						}
 					} else {
 						reason = writeErr.Error()
 						if strings.HasPrefix(reason, "auth-required:") {
@@ -267,14 +278,3 @@ 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")
-
-	info := *rl.Info
-	for _, ovw := range rl.OverwriteRelayInformation {
-		info = ovw(r.Context(), r, info)
-	}
-
-	json.NewEncoder(w).Encode(info)
-}

helpers.go

@@ -1,6 +1,7 @@
 package khatru
 
 import (
+	"net"
 	"net/http"
 	"strconv"
 	"strings"
@@ -34,3 +35,43 @@ func getServiceBaseURL(r *http.Request) string {
 	}
 	return proto + "://" + host
 }
+
+var privateMasks = func() []net.IPNet {
+	privateCIDRs := []string{
+		"127.0.0.0/8",
+		"10.0.0.0/8",
+		"172.16.0.0/12",
+		"192.168.0.0/16",
+		"fc00::/7",
+	}
+	masks := make([]net.IPNet, len(privateCIDRs))
+	for i, cidr := range privateCIDRs {
+		_, netw, err := net.ParseCIDR(cidr)
+		if err != nil {
+			return nil
+		}
+		masks[i] = *netw
+	}
+	return masks
+}()
+
+func isPrivate(ip net.IP) bool {
+	for _, mask := range privateMasks {
+		if mask.Contains(ip) {
+			return true
+		}
+	}
+	return false
+}
+
+func GetIPFromRequest(r *http.Request) string {
+	if xffh := r.Header.Get("X-Forwarded-For"); xffh != "" {
+		for _, v := range strings.Split(xffh, ",") {
+			if ip := net.ParseIP(strings.TrimSpace(v)); ip != nil && ip.IsGlobalUnicast() && !isPrivate(ip) {
+				return ip.String()
+			}
+		}
+	}
+	ip, _, _ := net.SplitHostPort(r.RemoteAddr)
+	return ip
+}

nip11.go

@@ -0,0 +1,25 @@
+package khatru
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+func (rl *Relay) HandleNIP11(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/nostr+json")
+
+	info := *rl.Info
+
+	if len(rl.DeleteEvent) > 0 {
+		info.SupportedNIPs = append(info.SupportedNIPs, 9)
+	}
+	if len(rl.CountEvents) > 0 {
+		info.SupportedNIPs = append(info.SupportedNIPs, 45)
+	}
+
+	for _, ovw := range rl.OverwriteRelayInformation {
+		info = ovw(r.Context(), r, info)
+	}
+
+	json.NewEncoder(w).Encode(info)
+}

nip86.go

@@ -0,0 +1,267 @@
+package khatru
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"reflect"
+	"strings"
+
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/nbd-wtf/go-nostr/nip86"
+)
+
+type RelayManagementAPI struct {
+	RejectAPICall []func(ctx context.Context, mp nip86.MethodParams) (reject bool, msg string)
+
+	BanPubKey                   func(ctx context.Context, pubkey string, reason string) error
+	ListBannedPubKeys           func(ctx context.Context) ([]nip86.PubKeyReason, error)
+	AllowPubKey                 func(ctx context.Context, pubkey string, reason string) error
+	ListAllowedPubKeys          func(ctx context.Context) ([]nip86.PubKeyReason, error)
+	ListEventsNeedingModeration func(ctx context.Context) ([]nip86.IDReason, error)
+	AllowEvent                  func(ctx context.Context, id string, reason string) error
+	BanEvent                    func(ctx context.Context, id string, reason string) error
+	ListBannedEvents            func(ctx context.Context) ([]nip86.IDReason, error)
+	ChangeRelayName             func(ctx context.Context, name string) error
+	ChangeRelayDescription      func(ctx context.Context, desc string) error
+	ChangeRelayIcon             func(ctx context.Context, icon string) error
+	AllowKind                   func(ctx context.Context, kind int) error
+	DisallowKind                func(ctx context.Context, kind int) error
+	ListAllowedKinds            func(ctx context.Context) ([]int, error)
+	BlockIP                     func(ctx context.Context, ip net.IP, reason string) error
+	UnblockIP                   func(ctx context.Context, ip net.IP, reason string) error
+	ListBlockedIPs              func(ctx context.Context) ([]nip86.IPReason, error)
+}
+
+func (rl *Relay) HandleNIP86(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/nostr+json+rpc")
+
+	var (
+		resp        nip86.Response
+		ctx         = r.Context()
+		req         nip86.Request
+		mp          nip86.MethodParams
+		evt         nostr.Event
+		payloadHash [32]byte
+	)
+
+	payload, err := io.ReadAll(r.Body)
+	if err != nil {
+		resp.Error = "empty request"
+		goto respond
+	}
+	payloadHash = sha256.Sum256(payload)
+
+	{
+		auth := r.Header.Get("Authorization")
+		spl := strings.Split(auth, "Nostr ")
+		if len(spl) != 2 {
+			resp.Error = "missing auth"
+			goto respond
+		}
+		if evtj, err := base64.StdEncoding.DecodeString(spl[1]); err != nil {
+			resp.Error = "invalid base64 auth"
+			goto respond
+		} else if err := json.Unmarshal(evtj, &evt); err != nil {
+			resp.Error = "invalid auth event json"
+			goto respond
+		} else if ok, _ := evt.CheckSignature(); !ok {
+			resp.Error = "invalid auth event"
+			goto respond
+		} else if pht := evt.Tags.GetFirst([]string{"payload", hex.EncodeToString(payloadHash[:])}); pht == nil {
+			resp.Error = "invalid auth event payload hash"
+			goto respond
+		} else if evt.CreatedAt < nostr.Now()-30 {
+			resp.Error = "auth event is too old"
+			goto respond
+		}
+	}
+
+	if err := json.Unmarshal(payload, &req); err != nil {
+		resp.Error = "invalid json body"
+		goto respond
+	}
+
+	mp, err = nip86.DecodeRequest(req)
+	if err != nil {
+		resp.Error = fmt.Sprintf("invalid params: %s", err)
+		goto respond
+	}
+
+	ctx = context.WithValue(ctx, nip86HeaderAuthKey, evt.PubKey)
+	for _, rac := range rl.ManagementAPI.RejectAPICall {
+		if reject, msg := rac(ctx, mp); reject {
+			resp.Error = msg
+			goto respond
+		}
+	}
+
+	if _, ok := mp.(nip86.SupportedMethods); ok {
+		mat := reflect.TypeOf(rl.ManagementAPI)
+		mav := reflect.ValueOf(rl.ManagementAPI)
+
+		methods := make([]string, 0, mat.NumField())
+		for i := 0; i < mat.NumField(); i++ {
+			field := mat.Field(i)
+
+			// danger: this assumes the struct fields are appropriately named
+			methodName := strings.ToLower(field.Name)
+
+			// assign this only if the function was defined
+			if mav.Field(i).Interface() != nil {
+				methods[i] = methodName
+			}
+		}
+		resp.Result = methods
+	} else {
+		switch thing := mp.(type) {
+		case nip86.BanPubKey:
+			if rl.ManagementAPI.BanPubKey == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.BanPubKey(ctx, thing.PubKey, thing.Reason); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.ListBannedPubKeys:
+			if rl.ManagementAPI.ListBannedPubKeys == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if result, err := rl.ManagementAPI.ListBannedPubKeys(ctx); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = result
+			}
+		case nip86.AllowPubKey:
+			if rl.ManagementAPI.AllowPubKey == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.AllowPubKey(ctx, thing.PubKey, thing.Reason); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.ListAllowedPubKeys:
+			if rl.ManagementAPI.ListAllowedPubKeys == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if result, err := rl.ManagementAPI.ListAllowedPubKeys(ctx); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = result
+			}
+		case nip86.BanEvent:
+			if rl.ManagementAPI.BanEvent == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.BanEvent(ctx, thing.ID, thing.Reason); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.AllowEvent:
+			if rl.ManagementAPI.AllowEvent == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.AllowEvent(ctx, thing.ID, thing.Reason); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.ListEventsNeedingModeration:
+			if rl.ManagementAPI.ListEventsNeedingModeration == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if result, err := rl.ManagementAPI.ListEventsNeedingModeration(ctx); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = result
+			}
+		case nip86.ListBannedEvents:
+			if rl.ManagementAPI.ListBannedEvents == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if result, err := rl.ManagementAPI.ListEventsNeedingModeration(ctx); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = result
+			}
+		case nip86.ChangeRelayName:
+			if rl.ManagementAPI.ChangeRelayName == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.ChangeRelayName(ctx, thing.Name); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.ChangeRelayDescription:
+			if rl.ManagementAPI.ChangeRelayDescription == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.ChangeRelayDescription(ctx, thing.Description); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.ChangeRelayIcon:
+			if rl.ManagementAPI.ChangeRelayIcon == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.ChangeRelayIcon(ctx, thing.IconURL); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.AllowKind:
+			if rl.ManagementAPI.AllowKind == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.AllowKind(ctx, thing.Kind); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.DisallowKind:
+			if rl.ManagementAPI.DisallowKind == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.DisallowKind(ctx, thing.Kind); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.ListAllowedKinds:
+			if rl.ManagementAPI.ListAllowedKinds == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if result, err := rl.ManagementAPI.ListAllowedKinds(ctx); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = result
+			}
+		case nip86.BlockIP:
+			if rl.ManagementAPI.BlockIP == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.BlockIP(ctx, thing.IP, thing.Reason); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.UnblockIP:
+			if rl.ManagementAPI.UnblockIP == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if err := rl.ManagementAPI.UnblockIP(ctx, thing.IP, thing.Reason); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = true
+			}
+		case nip86.ListBlockedIPs:
+			if rl.ManagementAPI.ListBlockedIPs == nil {
+				resp.Error = fmt.Sprintf("method %s not supported", thing.MethodName())
+			} else if result, err := rl.ManagementAPI.ListBlockedIPs(ctx); err != nil {
+				resp.Error = err.Error()
+			} else {
+				resp.Result = result
+			}
+		default:
+			resp.Error = fmt.Sprintf("method '%s' not known", mp.MethodName())
+		}
+	}
+
+respond:
+	json.NewEncoder(w).Encode(resp)
+}

policies/events.go

@@ -2,8 +2,9 @@ package policies
 
 import (
 	"context"
-
+	"fmt"
 	"slices"
+	"strings"
 
 	"github.com/nbd-wtf/go-nostr"
 )
@@ -14,6 +15,9 @@ import (
 // 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) {
+	slices.Sort(ignoreKinds)
+	slices.Sort(onlyKinds)
+
 	ignore := func(kind int) bool { return false }
 	if len(ignoreKinds) > 0 {
 		ignore = func(kind int) bool {
@@ -63,32 +67,15 @@ func PreventLargeTags(maxTagValueLen int) func(context.Context, *nostr.Event) (b
 // RestrictToSpecifiedKinds returns a function that can be used as a RejectFilter that will reject
 // any events with kinds different than the specified ones.
 func RestrictToSpecifiedKinds(kinds ...uint16) func(context.Context, *nostr.Event) (bool, string) {
-	max := 0
-	min := 0
-	for _, kind := range kinds {
-		if int(kind) > max {
-			max = int(kind)
-		}
-		if int(kind) < min {
-			min = int(kind)
-		}
-	}
+	// sort the kinds in increasing order
+	slices.Sort(kinds)
 
 	return func(ctx context.Context, event *nostr.Event) (reject bool, msg string) {
-		// these are cheap and very questionable optimizations, but they exist for a reason:
-		// we would have to ensure that the kind number is within the bounds of a uint16 anyway
-		if event.Kind > max {
-			return true, "event kind not allowed"
-		}
-		if event.Kind < min {
-			return true, "event kind not allowed"
-		}
-
-		// hopefully this map of uint16s is very fast
 		if _, allowed := slices.BinarySearch(kinds, uint16(event.Kind)); allowed {
 			return false, ""
 		}
-		return true, "event kind not allowed"
+
+		return true, fmt.Sprintf("received event kind %d not allowed", event.Kind)
 	}
 }
 
@@ -109,3 +96,7 @@ func PreventTimestampsInTheFuture(thresholdSeconds nostr.Timestamp) func(context
 		return false, ""
 	}
 }
+
+func RejectEventsWithBase64Media(ctx context.Context, evt *nostr.Event) (bool, string) {
+	return strings.Contains(evt.Content, "data:image/") || strings.Contains(evt.Content, "data:video/"), "event with base64 media"
+}

policies/filters.go

@@ -2,7 +2,6 @@ package policies
 
 import (
 	"context"
-
 	"slices"
 
 	"github.com/nbd-wtf/go-nostr"
@@ -48,7 +47,7 @@ func NoSearchQueries(ctx context.Context, filter nostr.Filter) (reject bool, msg
 func RemoveSearchQueries(ctx context.Context, filter *nostr.Filter) {
 	if filter.Search != "" {
 		filter.Search = ""
-		filter.Limit = -1 // signals that this query should be just skipped
+		filter.LimitZero = true // signals that this query should be just skipped
 	}
 }
 
@@ -63,7 +62,7 @@ func RemoveAllButKinds(kinds ...uint16) func(context.Context, *nostr.Filter) {
 			}
 			filter.Kinds = newKinds
 			if len(filter.Kinds) == 0 {
-				filter.Limit = -1 // signals that this query should be just skipped
+				filter.LimitZero = true // signals that this query should be just skipped
 			}
 		}
 	}
@@ -78,7 +77,7 @@ func RemoveAllButTags(tagNames ...string) func(context.Context, *nostr.Filter) {
 				}
 			}
 			if len(filter.Tags) == 0 {
-				filter.Limit = -1 // signals that this query should be just skipped
+				filter.LimitZero = true // signals that this query should be just skipped
 			}
 		}
 	}

policies/helpers.go

@@ -0,0 +1,43 @@
+package policies
+
+import (
+	"sync/atomic"
+	"time"
+
+	"github.com/puzpuzpuz/xsync/v3"
+)
+
+func startRateLimitSystem[K comparable](
+	tokensPerInterval int,
+	interval time.Duration,
+	maxTokens int,
+) func(key K) (ratelimited bool) {
+	negativeBuckets := xsync.NewMapOf[K, *atomic.Int32]()
+	maxTokensInt32 := int32(maxTokens)
+
+	go func() {
+		for {
+			time.Sleep(interval)
+			negativeBuckets.Range(func(key K, bucket *atomic.Int32) bool {
+				newv := bucket.Add(int32(-tokensPerInterval))
+				if newv <= 0 {
+					negativeBuckets.Delete(key)
+				}
+				return true
+			})
+		}
+	}()
+
+	return func(key K) bool {
+		nb, _ := negativeBuckets.LoadOrStore(key, &atomic.Int32{})
+
+		if nb.Load() < maxTokensInt32 {
+			nb.Add(1)
+			// rate limit not reached yet
+			return false
+		}
+
+		// rate limit reached
+		return true
+	}
+}

policies/ratelimits.go

@@ -0,0 +1,42 @@
+package policies
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"github.com/fiatjaf/khatru"
+	"github.com/nbd-wtf/go-nostr"
+)
+
+func EventIPRateLimiter(tokensPerInterval int, interval time.Duration, maxTokens int) func(ctx context.Context, _ *nostr.Event) (reject bool, msg string) {
+	rl := startRateLimitSystem[string](tokensPerInterval, interval, maxTokens)
+
+	return func(ctx context.Context, _ *nostr.Event) (reject bool, msg string) {
+		return rl(khatru.GetIP(ctx)), "rate-limited: slow down, please"
+	}
+}
+
+func EventPubKeyRateLimiter(tokensPerInterval int, interval time.Duration, maxTokens int) func(ctx context.Context, _ *nostr.Event) (reject bool, msg string) {
+	rl := startRateLimitSystem[string](tokensPerInterval, interval, maxTokens)
+
+	return func(ctx context.Context, evt *nostr.Event) (reject bool, msg string) {
+		return rl(evt.PubKey), "rate-limited: slow down, please"
+	}
+}
+
+func ConnectionRateLimiter(tokensPerInterval int, interval time.Duration, maxTokens int) func(r *http.Request) bool {
+	rl := startRateLimitSystem[string](tokensPerInterval, interval, maxTokens)
+
+	return func(r *http.Request) bool {
+		return rl(khatru.GetIPFromRequest(r))
+	}
+}
+
+func FilterIPRateLimiter(tokensPerInterval int, interval time.Duration, maxTokens int) func(ctx context.Context, _ nostr.Filter) (reject bool, msg string) {
+	rl := startRateLimitSystem[string](tokensPerInterval, interval, maxTokens)
+
+	return func(ctx context.Context, _ nostr.Filter) (reject bool, msg string) {
+		return rl(khatru.GetIP(ctx)), "rate-limited: there is a bug in the client, no one should be making so many requests"
+	}
+}

policies/sane_defaults.go

@@ -0,0 +1,24 @@
+package policies
+
+import (
+	"time"
+
+	"github.com/fiatjaf/khatru"
+)
+
+func ApplySaneDefaults(relay *khatru.Relay) {
+	relay.RejectEvent = append(relay.RejectEvent,
+		RejectEventsWithBase64Media,
+		EventIPRateLimiter(2, time.Minute*3, 5),
+	)
+
+	relay.RejectFilter = append(relay.RejectFilter,
+		NoEmptyFilters,
+		NoComplexFilters,
+		FilterIPRateLimiter(20, time.Minute, 100),
+	)
+
+	relay.RejectConnection = append(relay.RejectConnection,
+		ConnectionRateLimiter(1, time.Minute*5, 3),
+	)
+}

relay.go

@@ -20,7 +20,7 @@ func NewRelay() *Relay {
 		Info: &nip11.RelayInformationDocument{
 			Software:      "https://github.com/fiatjaf/khatru",
 			Version:       "n/a",
-			SupportedNIPs: []int{1, 11, 70},
+			SupportedNIPs: []int{1, 11, 42, 70, 86},
 		},
 
 		upgrader: websocket.Upgrader{
@@ -45,6 +45,7 @@ type Relay struct {
 	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)
+	RejectConnection          []func(r *http.Request) bool
 	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)
@@ -59,7 +60,10 @@ type Relay struct {
 	OnEventSaved              []func(ctx context.Context, event *nostr.Event)
 	OnEphemeralEvent          []func(ctx context.Context, event *nostr.Event)
 
-	// editing info will affect
+	// setting up handlers here will enable these methods
+	ManagementAPI RelayManagementAPI
+
+	// editing info will affect the NIP-11 responses
 	Info *nip11.RelayInformationDocument
 
 	// Default logger, as set by NewServer, is a stdlib logger prefixed with "[khatru-relay] ",

responding.go

@@ -17,9 +17,8 @@ func (rl *Relay) handleRequest(ctx context.Context, id string, eose *sync.WaitGr
 		ovw(ctx, &filter)
 	}
 
-	if filter.Limit < 0 {
-		// this is a special situation through which the implementor signals to us that it doesn't want
-		// to event perform any queries whatsoever
+	if filter.LimitZero {
+		// don't do any queries, just subscribe to future events
 		return nil
 	}
 
@@ -29,7 +28,6 @@ func (rl *Relay) handleRequest(ctx context.Context, id string, eose *sync.WaitGr
 	// filter we can just reject it)
 	for _, reject := range rl.RejectFilter {
 		if reject, msg := reject(ctx, filter); reject {
-			ws.WriteJSON(nostr.NoticeEnvelope(msg))
 			return errors.New(nostr.NormalizeOKMessage(msg, "blocked"))
 		}
 	}
@@ -43,6 +41,9 @@ func (rl *Relay) handleRequest(ctx context.Context, id string, eose *sync.WaitGr
 			ws.WriteJSON(nostr.NoticeEnvelope(err.Error()))
 			eose.Done()
 			continue
+		} else if ch == nil {
+			eose.Done()
+			continue
 		}
 
 		go func(ch chan *nostr.Event) {

utils.go

@@ -4,12 +4,12 @@ import (
 	"context"
 
 	"github.com/nbd-wtf/go-nostr"
-	"github.com/sebest/xff"
 )
 
 const (
 	wsKey = iota
 	subscriptionIdKey
+	nip86HeaderAuthKey
 )
 
 func RequestAuth(ctx context.Context) {
@@ -23,15 +23,25 @@ func RequestAuth(ctx context.Context) {
 }
 
 func GetConnection(ctx context.Context) *WebSocket {
-	return ctx.Value(wsKey).(*WebSocket)
+	wsi := ctx.Value(wsKey)
+	if wsi != nil {
+		return wsi.(*WebSocket)
+	}
+	return nil
 }
 
 func GetAuthed(ctx context.Context) string {
-	return GetConnection(ctx).AuthedPublicKey
+	if conn := GetConnection(ctx); conn != nil {
+		return conn.AuthedPublicKey
+	}
+	if nip86Auth := ctx.Value(nip86HeaderAuthKey); nip86Auth != nil {
+		return nip86Auth.(string)
+	}
+	return ""
 }
 
 func GetIP(ctx context.Context) string {
-	return xff.GetRemoteAddr(GetConnection(ctx).Request)
+	return GetIPFromRequest(GetConnection(ctx).Request)
 }
 
 func GetSubscriptionID(ctx context.Context) string {