when LimitZero don't do any database queries.

README.md

@@ -69,6 +69,11 @@ func main() {
 
 	// there are many other configurable things you can set
 	relay.RejectEvent = append(relay.RejectEvent,
+		// built-in policies
+		policies.ValidateKind,
+
+		// define your own policies
+		policies.PreventLargeTags(80),
 		func(ctx context.Context, event *nostr.Event) (reject bool, msg string) {
 			if event.PubKey == "fa984bd7dbb282f07e16e7ae87b26a2a7b9b90b7246a44771f0cf5ae58018f52" {
 				return true, "we don't allow this person to write here"
@@ -79,6 +84,10 @@ func main() {
 
 	// you can request auth by rejecting an event or a request with the prefix "auth-required: "
 	relay.RejectFilter = append(relay.RejectFilter,
+		// built-in policies
+		policies.NoComplexFilters,
+
+		// define your own policies
 		func(ctx context.Context, filter nostr.Filter) (reject bool, msg string) {
 			if pubkey := khatru.GetAuthed(ctx); pubkey != "" {
 				log.Printf("request from %s\n", pubkey)

adding.go

@@ -79,10 +79,5 @@ func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
 		}
 	}
 
-	for _, ovw := range rl.OverwriteResponseEvent {
-		ovw(ctx, evt)
-	}
-	notifyListeners(evt)
-
 	return nil
 }

examples/basic-elasticsearch/main.go

@@ -4,8 +4,8 @@ import (
 	"fmt"
 	"net/http"
 
-	"github.com/fiatjaf/khatru"
 	"github.com/fiatjaf/eventstore/elasticsearch"
+	"github.com/fiatjaf/khatru"
 )
 
 func main() {

examples/basic-postgres/main.go

@@ -4,8 +4,8 @@ import (
 	"fmt"
 	"net/http"
 
-	"github.com/fiatjaf/khatru"
 	"github.com/fiatjaf/eventstore/postgresql"
+	"github.com/fiatjaf/khatru"
 )
 
 func main() {

examples/basic-sqlite3/main.go

@@ -4,8 +4,8 @@ import (
 	"fmt"
 	"net/http"
 
-	"github.com/fiatjaf/khatru"
 	"github.com/fiatjaf/eventstore/sqlite3"
+	"github.com/fiatjaf/khatru"
 )
 
 func main() {

examples/readme-demo/main.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 
 	"github.com/fiatjaf/khatru"
+	"github.com/fiatjaf/khatru/policies"
 	"github.com/nbd-wtf/go-nostr"
 )
 
@@ -53,6 +54,11 @@ func main() {
 
 	// there are many other configurable things you can set
 	relay.RejectEvent = append(relay.RejectEvent,
+		// built-in policies
+		policies.ValidateKind,
+
+		// define your own policies
+		policies.PreventLargeTags(80),
 		func(ctx context.Context, event *nostr.Event) (reject bool, msg string) {
 			if event.PubKey == "fa984bd7dbb282f07e16e7ae87b26a2a7b9b90b7246a44771f0cf5ae58018f52" {
 				return true, "we don't allow this person to write here"
@@ -63,6 +69,10 @@ func main() {
 
 	// you can request auth by rejecting an event or a request with the prefix "auth-required: "
 	relay.RejectFilter = append(relay.RejectFilter,
+		// built-in policies
+		policies.NoComplexFilters,
+
+		// define your own policies
 		func(ctx context.Context, filter nostr.Filter) (reject bool, msg string) {
 			if pubkey := khatru.GetAuthed(ctx); pubkey != "" {
 				log.Printf("request from %s\n", pubkey)

go.mod

@@ -3,13 +3,12 @@ module github.com/fiatjaf/khatru
 go 1.21.4
 
 require (
-	github.com/fasthttp/websocket v1.5.3
-	github.com/fiatjaf/eventstore v0.3.1
-	github.com/nbd-wtf/go-nostr v0.28.0
+	github.com/fasthttp/websocket v1.5.7
+	github.com/fiatjaf/eventstore v0.3.8
+	github.com/nbd-wtf/go-nostr v0.30.0
 	github.com/puzpuzpuz/xsync/v3 v3.0.2
 	github.com/rs/cors v1.7.0
 	github.com/sebest/xff v0.0.0-20210106013422-671bd2870b3a
-	golang.org/x/exp v0.0.0-20231006140011-7918f672742d
 )
 
 require (
@@ -39,7 +38,7 @@ 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 v1.17.2 // indirect
+	github.com/klauspost/compress v1.17.3 // 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
@@ -49,9 +48,10 @@ require (
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.1 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
-	github.com/valyala/fasthttp v1.47.0 // indirect
+	github.com/valyala/fasthttp v1.51.0 // indirect
 	go.opencensus.io v0.24.0 // indirect
-	golang.org/x/net v0.17.0 // 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
 	google.golang.org/protobuf v1.31.0 // indirect
 )

go.sum

@@ -43,12 +43,12 @@ github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymF
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
-github.com/fasthttp/websocket v1.5.3 h1:TPpQuLwJYfd4LJPXvHDYPMFWbLjsT91n3GpWtCQtdek=
-github.com/fasthttp/websocket v1.5.3/go.mod h1:46gg/UBmTU1kUaTcwQXpUxtRwG2PvIZYeA8oL6vF3Fs=
+github.com/fasthttp/websocket v1.5.7 h1:0a6o2OfeATvtGgoMKleURhLT6JqWPg7fYfWnH4KHau4=
+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 v0.3.1 h1:GDuF8RxBNL6km9Y7qEucDQbkzKfkPJqoA/YiiIE0wao=
-github.com/fiatjaf/eventstore v0.3.1/go.mod h1:q3r6SuNhCxaSwfnK++2BratEVUcwK2NNr004hLOpz7Q=
+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/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 v1.17.2 h1:RlWWUY/Dr4fL8qk9YG7DTZ7PDgME2V4csBXA8L/ixi4=
-github.com/klauspost/compress v1.17.2/go.mod h1:ntbaceVETuRiXiv4DpjP66DpAtAGkEQskQzEyD//IeE=
+github.com/klauspost/compress v1.17.3 h1:qkRjuerhUU1EmXLYGkSH6EZL+vPSxIrYjLNAK4slzwA=
+github.com/klauspost/compress v1.17.3/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6KH9zAO4BDxPM=
 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 +113,10 @@ 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 v0.28.0 h1:SLYyoFeCNYb7HyWtmPUzD6rifBOMR66Spj5fzCk+5GE=
-github.com/nbd-wtf/go-nostr v0.28.0/go.mod h1:OQ8sNLFJnsj17BdqZiLSmjJBIFTfDqckEYC3utS4qoY=
+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 v0.30.0 h1:rN085pe4IxmSBVht8LChZbWLggonjA8hPIk8l4/+Hjk=
+github.com/nbd-wtf/go-nostr v0.30.0/go.mod h1:tiKJY6fWYSujbTQb201Y+IQ3l4szqYVt+fsTnsm7FCk=
 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=
@@ -146,8 +148,8 @@ github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
 github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
-github.com/valyala/fasthttp v1.47.0 h1:y7moDoxYzMooFpT5aHgNgVOQDrS3qlkfiP9mDtGGK9c=
-github.com/valyala/fasthttp v1.47.0/go.mod h1:k2zXd82h/7UZc3VOdJ2WaUqt1uZ/XpXAfE9i+HBC3lA=
+github.com/valyala/fasthttp v1.51.0 h1:8b30A5JlZ6C7AS81RsWjYMQmrZG6feChmgAolCl1SqA=
+github.com/valyala/fasthttp v1.51.0/go.mod h1:oI2XroL+lI7vdXyYoQk03bXBThfFl2cVdIA3Xl7cH8g=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 go.opencensus.io v0.24.0 h1:y73uSU6J157QMP2kn2r30vwW1A2W2WFwSCGnAVxeaD0=
@@ -172,8 +174,8 @@ golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLL
 golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
-golang.org/x/net v0.17.0 h1:pVaXccu2ozPjCXewfr1S7xza/zcXTity9cCdXQYSjIM=
-golang.org/x/net v0.17.0/go.mod h1:NxSsAGuq816PNPmqtQdLE42eU2Fs7NoRIZrHJAlaCOE=
+golang.org/x/net v0.18.0 h1:mIYleuAkSbHh0tCv7RvjL3F6ZVbLjq4+R7zbOn3Kokg=
+golang.org/x/net v0.18.0/go.mod h1:/czyP5RqHAH4odGYxBJ1qz0+CE5WZ+2j1YgoEo8F2jQ=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=

handlers.go

@@ -134,6 +134,31 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 						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
+							}
+						}
+					}
+
 					var ok bool
 					var writeErr error
 					if env.Event.Kind == 5 {
@@ -147,6 +172,10 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 					var reason string
 					if writeErr == nil {
 						ok = true
+						for _, ovw := range rl.OverwriteResponseEvent {
+							ovw(ctx, &env.Event)
+						}
+						notifyListeners(&env.Event)
 					} else {
 						reason = writeErr.Error()
 						if strings.HasPrefix(reason, "auth-required:") {

policies/events.go

@@ -3,8 +3,9 @@ package policies
 import (
 	"context"
 
+	"slices"
+
 	"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

policies/filters.go

@@ -2,9 +2,9 @@ package policies
 
 import (
 	"context"
+	"slices"
 
 	"github.com/nbd-wtf/go-nostr"
-	"golang.org/x/exp/slices"
 )
 
 // NoComplexFilters disallows filters with more than 2 tags.
@@ -45,7 +45,10 @@ func NoSearchQueries(ctx context.Context, filter nostr.Filter) (reject bool, msg
 }
 
 func RemoveSearchQueries(ctx context.Context, filter *nostr.Filter) {
-	filter.Search = ""
+	if filter.Search != "" {
+		filter.Search = ""
+		filter.LimitZero = true // signals that this query should be just skipped
+	}
 }
 
 func RemoveAllButKinds(kinds ...uint16) func(context.Context, *nostr.Filter) {
@@ -58,15 +61,23 @@ func RemoveAllButKinds(kinds ...uint16) func(context.Context, *nostr.Filter) {
 				}
 			}
 			filter.Kinds = newKinds
+			if len(filter.Kinds) == 0 {
+				filter.LimitZero = true // signals that this query should be just skipped
+			}
 		}
 	}
 }
 
 func RemoveAllButTags(tagNames ...string) func(context.Context, *nostr.Filter) {
 	return func(ctx context.Context, filter *nostr.Filter) {
-		for tagName := range filter.Tags {
-			if !slices.Contains(tagNames, tagName) {
-				delete(filter.Tags, tagName)
+		if n := len(filter.Tags); n > 0 {
+			for tagName := range filter.Tags {
+				if !slices.Contains(tagNames, tagName) {
+					delete(filter.Tags, tagName)
+				}
+			}
+			if len(filter.Tags) == 0 {
+				filter.LimitZero = true // signals that this query should be just skipped
 			}
 		}
 	}

policies/kind_validation.go

@@ -0,0 +1,29 @@
+package policies
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+func ValidateKind(ctx context.Context, evt *nostr.Event) (bool, string) {
+	switch evt.Kind {
+	case 0:
+		var m struct {
+			Name string `json:"name"`
+		}
+		json.Unmarshal([]byte(evt.Content), &m)
+		if m.Name == "" {
+			return true, "missing json name in kind 0"
+		}
+	case 1:
+		return false, ""
+	case 2:
+		return true, "this kind has been deprecated"
+	}
+
+	// TODO: all other kinds
+
+	return false, ""
+}

policies/nip04.go

@@ -3,9 +3,10 @@ package policies
 import (
 	"context"
 
+	"slices"
+
 	"github.com/fiatjaf/khatru"
 	"github.com/nbd-wtf/go-nostr"
-	"golang.org/x/exp/slices"
 )
 
 // RejectKind04Snoopers prevents reading NIP-04 messages from people not involved in the conversation.

relay.go

@@ -20,7 +20,7 @@ func NewRelay() *Relay {
 		Info: &nip11.RelayInformationDocument{
 			Software:      "https://github.com/fiatjaf/khatru",
 			Version:       "n/a",
-			SupportedNIPs: make([]int, 0),
+			SupportedNIPs: []int{1, 11, 70},
 		},
 
 		upgrader: websocket.Upgrader{

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"))
 		}
 	}