feat(nip13): add nip13, pow. (#85)

config/parameters.go

@@ -89,18 +89,18 @@ func (c *Config) LoadParameters(db *database.Database) error {
 			Icon:           "https://raw.githubusercontent.com/dezh-tech/immortal/refs/heads/main/assets/images/immortal.png",
 			WebsocketServer: &websocket.Config{
 				Limitation: &websocket.Limitation{
-					MaxMessageLength:    8192,  // Maximum length of a single message (in bytes or characters)
-					MaxSubscriptions:    20,    // Maximum number of concurrent subscriptions a client can create
-					MaxFilters:          20,    // Maximum number of filters a client can apply in a subscription
-					MaxSubidLength:      256,   // Maximum length of a subscription identifier
-					MinPowDifficulty:    0,     // Minimum proof-of-work difficulty for publishing events
-					AuthRequired:        false, // Whether authentication is required for writes
-					PaymentRequired:     false, // Whether payment is required to interact with the relay
-					RestrictedWrites:    false, // Whether writes are restricted to authenticated or paying users
-					MaxEventTags:        1000,  // Maximum number of tags allowed in a single event
-					MaxContentLength:    4096,  // Maximum content length of an event (in bytes)
-					CreatedAtLowerLimit: 0,     // Earliest timestamp allowed for event creation
-					CreatedAtUpperLimit: 0,     // Latest timestamp allowed for event creation (0 for no limit)
+					MaxMessageLength:    8192,          // Maximum length of a single message (in bytes or characters)
+					MaxSubscriptions:    20,            // Maximum number of concurrent subscriptions a client can create
+					MaxFilters:          20,            // Maximum number of filters a client can apply in a subscription
+					MaxSubidLength:      256,           // Maximum length of a subscription identifier
+					MinPowDifficulty:    0,             // Minimum proof-of-work difficulty for publishing events
+					AuthRequired:        false,         // Whether authentication is required for writes
+					PaymentRequired:     false,         // Whether payment is required to interact with the relay
+					RestrictedWrites:    false,         // Whether writes are restricted to authenticated or paying users
+					MaxEventTags:        1000,          // Maximum number of tags allowed in a single event
+					MaxContentLength:    4096,          // Maximum content length of an event (in bytes)
+					CreatedAtLowerLimit: 0,             // Earliest timestamp allowed for event creation
+					CreatedAtUpperLimit: 2_147_483_647, // Latest timestamp allowed for event creation
 				},
 			},
 			Handler: &handler.Config{

documents/NIPs.md

@@ -5,7 +5,7 @@ The Immortal follows [NIPs](https://github.com/nostr-protocol/nips) and tries to
 - [X] **NIP-01**: Basic Protocol Flow Description
 - [ ] **NIP-09**: Event Deletion Request
 - [X] **NIP-11**: Relay Information Document
-- [ ] **NIP-13**: Proof of Work
+- [X] **NIP-13**: Proof of Work
 - [ ] **NIP-40**: Expiration Timestamp
 - [ ] **NIP-42**: Authentication of Clients to Relays
 - [ ] **NIP-50**: Search Capability

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/joho/godotenv v1.5.1
 	github.com/mailru/easyjson v0.7.7
 	github.com/prometheus/client_golang v1.20.4
-	github.com/redis/go-redis/v9 v9.6.2
+	github.com/redis/go-redis/v9 v9.7.0
 	github.com/stretchr/testify v1.9.0
 	github.com/tidwall/gjson v1.18.0
 	go.mongodb.org/mongo-driver v1.17.1

go.sum

@@ -55,8 +55,8 @@ github.com/prometheus/common v0.60.0 h1:+V9PAREWNvJMAuJ1x1BaWl9dewMW4YrHZQbx0sJN
 github.com/prometheus/common v0.60.0/go.mod h1:h0LYf1R1deLSKtD4Vdg8gy4RuOvENW2J/h19V5NADQw=
 github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
 github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
-github.com/redis/go-redis/v9 v9.6.2 h1:w0uvkRbc9KpgD98zcvo5IrVUsn0lXpRMuhNgiHDJzdk=
-github.com/redis/go-redis/v9 v9.6.2/go.mod h1:0C0c6ycQsdpVNQpxb1njEQIqkx5UcsM8FJCQLgE9+RA=
+github.com/redis/go-redis/v9 v9.7.0 h1:HhLSs+B6O021gwzl+locl0zEDnyNkxMtf/Z3NNBMa9E=
+github.com/redis/go-redis/v9 v9.7.0/go.mod h1:f6zhXITC7JUJIlPEiBOTXxJgPLdZcA93GewI7inzyWw=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=

server/websocket/config.go

@@ -1,18 +1,18 @@
 package websocket
 
 type Limitation struct {
-	MaxMessageLength    int  `bson:"max_message_length"     json:"max_message_length"` // todo.
-	MaxSubscriptions    int  `bson:"max_subscriptions"      json:"max_subscriptions"`
-	MaxFilters          int  `bson:"max_filters"            json:"max_filters"`
-	MaxSubidLength      int  `bson:"max_subid_length"       json:"max_subid_length"`
-	MinPowDifficulty    int  `bson:"min_pow_difficulty"     json:"min_pow_difficulty"` // todo.
-	AuthRequired        bool `bson:"auth_required"          json:"auth_required"`      // todo.
-	PaymentRequired     bool `bson:"payment_required"       json:"payment_required"`   // todo.
-	RestrictedWrites    bool `bson:"restricted_writes"      json:"restricted_writes"`  // todo.
-	MaxEventTags        int  `bson:"max_event_tags"         json:"max_event_tags"`     // todo.
-	MaxContentLength    int  `bson:"max_content_length"     json:"max_content_length"`
-	CreatedAtLowerLimit int  `bson:"created_at_lower_limit" json:"created_at_lower_limit"` // todo.
-	CreatedAtUpperLimit int  `bson:"created_at_upper_limit" json:"created_at_upper_limit"` // todo.
+	MaxMessageLength    int   `bson:"max_message_length"     json:"max_message_length"` // todo?.
+	MaxSubscriptions    int   `bson:"max_subscriptions"      json:"max_subscriptions"`
+	MaxFilters          int   `bson:"max_filters"            json:"max_filters"`
+	MaxSubidLength      int   `bson:"max_subid_length"       json:"max_subid_length"`
+	MinPowDifficulty    int   `bson:"min_pow_difficulty"     json:"min_pow_difficulty"`
+	AuthRequired        bool  `bson:"auth_required"          json:"auth_required"`     // todo.
+	PaymentRequired     bool  `bson:"payment_required"       json:"payment_required"`  // todo.
+	RestrictedWrites    bool  `bson:"restricted_writes"      json:"restricted_writes"` // todo.
+	MaxEventTags        int   `bson:"max_event_tags"         json:"max_event_tags"`
+	MaxContentLength    int   `bson:"max_content_length"     json:"max_content_length"`
+	CreatedAtLowerLimit int64 `bson:"created_at_lower_limit" json:"created_at_lower_limit"`
+	CreatedAtUpperLimit int64 `bson:"created_at_upper_limit" json:"created_at_upper_limit"`
 }
 
 type Config struct {

server/websocket/server.go

@@ -266,19 +266,6 @@ func (s *Server) handleEvent(conn *websocket.Conn, m message.Message) {
 		return
 	}
 
-	if len(msg.Event.Content) > s.config.Limitation.MaxContentLength {
-		okm := message.MakeOK(false,
-			"",
-			fmt.Sprintf("error: max limit of message length is %d", s.config.Limitation.MaxContentLength),
-		)
-
-		_ = conn.WriteMessage(1, okm)
-
-		status = limitsFail
-
-		return
-	}
-
 	eID := msg.Event.GetRawID()
 
 	qCtx, cancel := context.WithTimeout(context.Background(), s.redis.QueryTimeout)
@@ -309,6 +296,60 @@ func (s *Server) handleEvent(conn *websocket.Conn, m message.Message) {
 		return
 	}
 
+	if len(msg.Event.Content) > s.config.Limitation.MaxContentLength {
+		okm := message.MakeOK(false,
+			"",
+			fmt.Sprintf("error: max limit of content length is %d", s.config.Limitation.MaxContentLength),
+		)
+
+		_ = conn.WriteMessage(1, okm)
+
+		status = limitsFail
+
+		return
+	}
+
+	if msg.Event.Difficulty() < s.config.Limitation.MinPowDifficulty {
+		okm := message.MakeOK(false,
+			"",
+			fmt.Sprintf("error: min pow required is %d", s.config.Limitation.MinPowDifficulty),
+		)
+
+		_ = conn.WriteMessage(1, okm)
+
+		status = limitsFail
+
+		return
+	}
+
+	if len(msg.Event.Tags) < s.config.Limitation.MaxEventTags {
+		okm := message.MakeOK(false,
+			"",
+			fmt.Sprintf("error: max limit of tags count is %d", s.config.Limitation.MaxEventTags),
+		)
+
+		_ = conn.WriteMessage(1, okm)
+
+		status = limitsFail
+
+		return
+	}
+
+	if msg.Event.CreatedAt < s.config.Limitation.CreatedAtLowerLimit ||
+		msg.Event.CreatedAt > s.config.Limitation.CreatedAtUpperLimit {
+		okm := message.MakeOK(false,
+			"",
+			fmt.Sprintf("error: created at must be as least %d and at most %d",
+				s.config.Limitation.CreatedAtLowerLimit, s.config.Limitation.CreatedAtUpperLimit),
+		)
+
+		_ = conn.WriteMessage(1, okm)
+
+		status = limitsFail
+
+		return
+	}
+
 	if !msg.Event.Kind.IsEphemeral() {
 		err := s.handlers.HandleEvent(msg.Event)
 		if err != nil {

types/event/nip13.go

@@ -0,0 +1,30 @@
+package event
+
+import (
+	"encoding/hex"
+	"math/bits"
+)
+
+// Difficulty returns the leading zeros of event id in base-2.
+func (e *Event) Difficulty() int {
+	var zeros int
+	var b [1]byte
+
+	for i := 0; i < 64; i += 2 {
+		if e.ID[i:i+2] == "00" {
+			zeros += 8
+
+			continue
+		}
+
+		if _, err := hex.Decode(b[:], []byte{e.ID[i], e.ID[i+1]}); err != nil {
+			return -1
+		}
+
+		zeros += bits.LeadingZeros8(b[0])
+
+		break
+	}
+
+	return zeros
+}

types/event/nip13_test.go

@@ -0,0 +1,27 @@
+package event_test
+
+import (
+	"testing"
+
+	"github.com/dezh-tech/immortal/types/event"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDifficulty(t *testing.T) {
+	testCases := []struct {
+		result int
+		id     string
+	}{
+		{36, "000000000e9d97a1ab09fc381030b346cdd7a142ad57e6df0b46dc9bef6c7e2d"},
+		{22, "0000024d38993bae75a61e82710842305fac9cda280f541476c31426c42ca81a"},
+		{0, "f2775f4eeaa0aa45f66440490b45d6aede8d1ceb7ac443e6328763db5ce8d6e3"},
+		{7, "010b807e82a1417588be0bcd7606b2aae4163a365afe1f6c97404b17fc56d30b"},
+		{21, "000004f20d022b65dd961cbbdc157347dbd37ca375899fe38b40d174cccd8ee3"},
+		{18, "00003db72b8385511ef2c1dd5fb3a43988269c9d7f51986f03c1aecd675dc506"},
+	}
+
+	for _, tc := range testCases {
+		e := event.Event{ID: tc.id}
+		assert.Equal(t, tc.result, e.Difficulty())
+	}
+}