basic event and relaypool.

2025-03-17 21:32:56 +01:00 · 2021-01-31 11:05:09 -03:00 · 2021-01-31 11:05:09 -03:00 · 32c21eb652
commit 32c21eb652
5 changed files with 481 additions and 0 deletions
--- a/event/event.go
+++ b/event/event.go
@ -0,0 +1,150 @@
+package event
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math/big"
+
+	"github.com/fiatjaf/bip340"
+)
+
+const (
+	KindSetMetadata     uint8 = 0
+	KindTextNote        uint8 = 1
+	KindRecommendServer uint8 = 2
+	KindContactList     uint8 = 3
+)
+
+type Event struct {
+	ID string `json:"id"` // it's the hash of the serialized event
+
+	PubKey    string `json:"pubkey"`
+	CreatedAt uint32 `json:"created_at"`
+
+	Kind uint8 `json:"kind"`
+
+	Tags    Tags   `json:"tags"`
+	Content string `json:"content"`
+	Sig     string `json:"sig"`
+}
+
+type Tags []Tag
+
+func (t Tags) Scan(src interface{}) error {
+	var jtags []byte = make([]byte, 0)
+
+	switch v := src.(type) {
+	case []byte:
+		jtags = v
+	case string:
+		jtags = []byte(v)
+	default:
+		return errors.New("couldn't scan tags, it's not a json string")
+	}
+
+	json.Unmarshal(jtags, t)
+	return nil
+}
+
+type Tag []interface{}
+
+// Serialize outputs a byte array that can be hashed/signed to identify/authenticate
+func (evt *Event) Serialize() []byte {
+	// the serialization process is just putting everything into a JSON array
+	// so the order is kept
+	arr := make([]interface{}, 6)
+
+	// version: 0
+	arr[0] = 0
+
+	// pubkey
+	arr[1] = evt.PubKey
+
+	// created_at
+	arr[2] = int64(evt.CreatedAt)
+
+	// kind
+	arr[3] = int64(evt.Kind)
+
+	// tags
+	if evt.Tags != nil {
+		arr[4] = evt.Tags
+	} else {
+		arr[4] = make([]bool, 0)
+	}
+
+	// content
+	arr[5] = evt.Content
+
+	serialized, _ := json.Marshal(arr)
+	return serialized
+}
+
+// CheckSignature checks if the signature is valid for the id
+// (which is a hash of the serialized event content).
+// returns an error if the signature itself is invalid.
+func (evt Event) CheckSignature() (bool, error) {
+	// read and check pubkey
+	pubkeyb, err := hex.DecodeString(evt.PubKey)
+	if err != nil {
+		return false, err
+	}
+	if len(pubkeyb) != 32 {
+		return false, fmt.Errorf("pubkey must be 32 bytes, not %d", len(pubkeyb))
+	}
+
+	// check tags
+	for _, tag := range evt.Tags {
+		for _, item := range tag {
+			switch item.(type) {
+			case string, int64, float64, int, bool:
+				// fine
+			default:
+				// not fine
+				return false, fmt.Errorf("tag contains an invalid value %v", item)
+			}
+		}
+	}
+
+	sig, err := hex.DecodeString(evt.Sig)
+	if err != nil {
+		return false, fmt.Errorf("signature is invalid hex: %w", err)
+	}
+	if len(sig) != 64 {
+		return false, fmt.Errorf("signature must be 64 bytes, not %d", len(sig))
+	}
+
+	var p [32]byte
+	copy(p[:], pubkeyb)
+
+	var s [64]byte
+	copy(s[:], sig)
+
+	h := sha256.Sum256(evt.Serialize())
+
+	return bip340.Verify(p, h, s)
+}
+
+// Sign signs an event with a given privateKey
+func (evt Event) Sign(privateKey string) error {
+	h := sha256.Sum256(evt.Serialize())
+	s, _ := new(big.Int).SetString(privateKey, 16)
+
+	if s == nil {
+		return errors.New("invalid private key " + privateKey)
+	}
+
+	aux := make([]byte, 32)
+	rand.Read(aux)
+	sig, err := bip340.Sign(s, h, aux)
+	if err != nil {
+		return err
+	}
+
+	evt.Sig = hex.EncodeToString(sig[:])
+	return nil
+}
--- a/go.mod
+++ b/go.mod
@ -0,0 +1,8 @@
+module github.com/fiatjaf/go-nostr
+
+go 1.15
+
+require (
+	github.com/fiatjaf/bip340 v1.0.0
+	github.com/gorilla/websocket v1.4.2
+)
--- a/go.sum
+++ b/go.sum
@ -0,0 +1,48 @@
+github.com/aead/siphash v1.0.1/go.mod h1:Nywa3cDsYNNK3gaciGTWPwHt0wlpNV15vwmswBAUSII=
+github.com/btcsuite/btcd v0.0.0-20190109040709-5bda5314ca95 h1:bmv+LE3sbjb/M06u2DBi92imeKj7KnCUBOvyZYqI8d8=
+github.com/btcsuite/btcd v0.0.0-20190109040709-5bda5314ca95/go.mod h1:d3C0AkH6BRcvO8T0UEPu53cnw4IbV63x1bEjildYhO0=
+github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f/go.mod h1:TdznJufoqS23FtqVCzL0ZqgP5MqXbb4fg/WgDys70nA=
+github.com/btcsuite/btcutil v0.0.0-20180706230648-ab6388e0c60a/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
+github.com/btcsuite/btcutil v0.0.0-20190112041146-bf1e1be93589/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
+github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd/go.mod h1:HHNXQzUsZCxOoE+CPiyCTO6x34Zs86zZUiwtpXoGdtg=
+github.com/btcsuite/goleveldb v0.0.0-20160330041536-7834afc9e8cd/go.mod h1:F+uVaaLLH7j4eDXPRvw78tMflu7Ie2bzYOH4Y8rRKBY=
+github.com/btcsuite/goleveldb v1.0.0/go.mod h1:QiK9vBlgftBg6rWQIj6wFzbPfRjiykIEhBH4obrXJ/I=
+github.com/btcsuite/snappy-go v0.0.0-20151229074030-0bdef8d06723/go.mod h1:8woku9dyThutzjeg+3xrA5iCpBRH8XEEg3lh6TiUghc=
+github.com/btcsuite/snappy-go v1.0.0/go.mod h1:8woku9dyThutzjeg+3xrA5iCpBRH8XEEg3lh6TiUghc=
+github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792/go.mod h1:ghJtEyQwv5/p4Mg4C0fgbePVuGr935/5ddU9Z3TmDRY=
+github.com/btcsuite/winsvc v1.0.0/go.mod h1:jsenWakMcC0zFBFurPLEAyrnc/teJEM1O46fmI40EZs=
+github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fiatjaf/bip340 v1.0.0 h1:mpwbm+0KC9BXB/7/pnac4e4N1TiuppyEVXxtVAXj75k=
+github.com/fiatjaf/bip340 v1.0.0/go.mod h1:MxAz+5FQUTW4OT2gnCBC6Our486wmqf72ykZIrh7+is=
+github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
+github.com/jessevdk/go-flags v0.0.0-20141203071132-1679536dcc89/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
+github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
+github.com/jrick/logrotate v1.0.0/go.mod h1:LNinyqDIJnpAur+b8yyulnQw/wDuN1+BYKlTRt3OuAQ=
+github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6CZQHDETBtE9HaSEkGmuNXF86RwHhHUvq4=
+github.com/kkdai/bstream v0.0.0-20181106074824-b3251f7901ec/go.mod h1:J+Gs4SYgM6CZQHDETBtE9HaSEkGmuNXF86RwHhHUvq4=
+github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
+github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
+github.com/onsi/gomega v1.4.1/go.mod h1:C1qb7wdrVGGVU+Z6iS04AVkA3Q65CEZX59MT0QO5uiA=
+github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
+golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/crypto v0.0.0-20190103213133-ff983b9c42bc/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/net v0.0.0-20180719180050-a680a1efc54d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190110200230-915654e7eabc/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190109145017-48ac38b7c8cb/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
+gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
+gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
--- a/relaypool/relaypool.go
+++ b/relaypool/relaypool.go
@ -0,0 +1,243 @@
+package relaypool
+
+import (
+	"encoding/json"
+	"errors"
+	"log"
+
+	"github.com/fiatjaf/go-nostr/event"
+	nostrutils "github.com/fiatjaf/go-nostr/utils"
+	"github.com/gorilla/websocket"
+)
+
+type RelayPool struct {
+	SecretKey *string
+
+	Relays     map[string]Policy
+	websockets map[string]*websocket.Conn
+
+	Events  chan *EventMessage
+	Notices chan *NoticeMessage
+
+	SubscribedKeys   []string
+	SubscribedEvents []string
+}
+
+type Policy struct {
+	SimplePolicy
+	ReadSpecific map[string]SimplePolicy
+}
+
+type SimplePolicy struct {
+	Read  bool
+	Write bool
+}
+
+type EventMessage struct {
+	Event   event.Event
+	Context byte
+	Relay   string
+}
+
+func (em *EventMessage) UnmarshalJSON(b []byte) error {
+	var temp []json.RawMessage
+	if err := json.Unmarshal(b, temp); err != nil {
+		return err
+	}
+	if len(temp) < 2 {
+		return errors.New("message is not an array of 2 or more")
+	}
+	if err := json.Unmarshal(temp[0], em.Event); err != nil {
+		return err
+	}
+	var context string
+	if err := json.Unmarshal(temp[1], &context); err != nil {
+		return err
+	}
+	em.Context = context[0]
+	return nil
+}
+
+type NoticeMessage struct {
+	Message string
+	Relay   string
+}
+
+func (nm *NoticeMessage) UnmarshalJSON(b []byte) error {
+	var temp []json.RawMessage
+	if err := json.Unmarshal(b, temp); err != nil {
+		return err
+	}
+	if len(temp) < 2 {
+		return errors.New("message is not an array of 2 or more")
+	}
+	var tag string
+	if err := json.Unmarshal(temp[0], &tag); err != nil {
+		return err
+	}
+	if tag != "notice" {
+		return errors.New("tag is not 'notice'")
+	}
+
+	if err := json.Unmarshal(temp[1], &nm.Message); err != nil {
+		return err
+	}
+	return nil
+}
+
+// New creates a new RelayPool with no relays in it
+func New() *RelayPool {
+	return &RelayPool{
+		Relays:     make(map[string]Policy),
+		websockets: make(map[string]*websocket.Conn),
+
+		Events:  make(chan *EventMessage),
+		Notices: make(chan *NoticeMessage),
+	}
+}
+
+// Add adds a new relay to the pool, if policy is nil, it will be a simple
+// read+write policy.
+func (r *RelayPool) Add(url string, policy *Policy) {
+	if policy == nil {
+		policy = &Policy{SimplePolicy: SimplePolicy{Read: true, Write: true}}
+	}
+
+	nm := nostrutils.NormalizeURL(url)
+	if nm == "" {
+		return
+	}
+
+	r.Relays[nm] = *policy
+	conn, _, err := websocket.DefaultDialer.Dial(nostrutils.WebsocketURL(url), nil)
+	if err != nil {
+		return
+	}
+
+	defer r.Remove(nm)
+	done := make(chan struct{})
+
+	r.websockets[nm] = conn
+
+	go func() {
+		defer close(done)
+		for {
+			typ, message, err := conn.ReadMessage()
+			if err != nil {
+				log.Println("read error: ", err)
+				return
+			}
+			if typ == websocket.PingMessage {
+				conn.WriteMessage(websocket.PongMessage, nil)
+			}
+
+			if typ != websocket.TextMessage || len(message) == 0 || message[0] != '[' {
+				continue
+			}
+
+			var noticeMessage *NoticeMessage
+			var eventMessage *EventMessage
+			err = json.Unmarshal(message, eventMessage)
+			if err == nil {
+				eventMessage.Relay = nm
+				r.Events <- eventMessage
+			} else {
+				err = json.Unmarshal(message, noticeMessage)
+				if err == nil {
+					noticeMessage.Relay = nm
+					r.Notices <- noticeMessage
+				} else {
+					continue
+				}
+			}
+		}
+	}()
+}
+
+// Remove removes a relay from the pool.
+func (r *RelayPool) Remove(url string) {
+	nm := nostrutils.NormalizeURL(url)
+	if conn, ok := r.websockets[nm]; ok {
+		conn.Close()
+	}
+	delete(r.Relays, nm)
+	delete(r.websockets, nm)
+}
+
+func (r *RelayPool) SubKey(key string) {
+	for _, conn := range r.websockets {
+		conn.WriteMessage(websocket.TextMessage, []byte("sub-key:"+key))
+	}
+}
+
+func (r *RelayPool) UnsubKey(key string) {
+	for _, conn := range r.websockets {
+		conn.WriteMessage(websocket.TextMessage, []byte("unsub-key:"+key))
+	}
+}
+
+func (r *RelayPool) SubEvent(id string) {
+	for _, conn := range r.websockets {
+		conn.WriteMessage(websocket.TextMessage, []byte("sub-event:"+id))
+	}
+}
+
+func (r *RelayPool) ReqFeed(opts map[string]interface{}) {
+	var sopts string
+	if opts == nil {
+		sopts = "{}"
+	} else {
+		jopts, _ := json.Marshal(opts)
+		sopts = string(jopts)
+	}
+
+	for _, conn := range r.websockets {
+		conn.WriteMessage(websocket.TextMessage, []byte("req-feed:"+sopts))
+	}
+}
+
+func (r *RelayPool) ReqEvent(id string, opts map[string]interface{}) {
+	if opts == nil {
+		opts = make(map[string]interface{})
+	}
+	opts["id"] = id
+
+	jopts, _ := json.Marshal(opts)
+	sopts := string(jopts)
+
+	for _, conn := range r.websockets {
+		conn.WriteMessage(websocket.TextMessage, []byte("req-event:"+sopts))
+	}
+}
+
+func (r *RelayPool) ReqKey(key string, opts map[string]interface{}) {
+	if opts == nil {
+		opts = make(map[string]interface{})
+	}
+	opts["key"] = key
+
+	jopts, _ := json.Marshal(opts)
+	sopts := string(jopts)
+
+	for _, conn := range r.websockets {
+		conn.WriteMessage(websocket.TextMessage, []byte("req-key:"+sopts))
+	}
+}
+
+func (r *RelayPool) PublishEvent(evt *event.Event) error {
+	if r.SecretKey == nil && evt.Sig == "" {
+		return errors.New("PublishEvent needs either a signed event to publish or to have been configured with a .SecretKey.")
+	}
+
+	if evt.Sig == "" {
+		evt.Sign(*r.SecretKey)
+	}
+
+	jevt, _ := json.Marshal(evt)
+
+	for _, conn := range r.websockets {
+		conn.WriteMessage(websocket.TextMessage, jevt)
+	}
+
+	return nil
+}
--- a/utils/utils.go
+++ b/utils/utils.go
@ -0,0 +1,32 @@
+package nostrutils
+
+import (
+	"net/url"
+	"strings"
+)
+
+func NormalizeURL(u string) string {
+	if !strings.HasPrefix(u, "http") && !strings.HasPrefix(u, "ws") {
+		u = "ws://" + u
+	}
+	p, err := url.Parse(u)
+	if err != nil {
+		return ""
+	}
+
+	if strings.HasSuffix(p.RawPath, "/") {
+		p.RawPath = p.RawPath[0 : len(p.RawPath)-1]
+	}
+
+	if strings.HasSuffix(p.RawPath, "/ws") {
+		p.RawPath = p.RawPath[0 : len(p.RawPath)-3]
+	}
+
+	return p.String()
+}
+
+func WebsocketURL(u string) string {
+	p, _ := url.Parse(NormalizeURL(u))
+	p.RawPath += "/ws"
+	return p.String()
+}