docs: add reverse proxy security note to login rate limiting section

Add a token-bucket rate limiter (golang.org/x/time/rate) that limits
login attempts per client IP on POST /api/v1/login. Returns 429 Too
Many Requests with a Retry-After header when the limit is exceeded.

Configurable via LOGIN_RATE_LIMIT (requests/sec, default 1) and
LOGIN_RATE_BURST (burst size, default 5). Stale per-IP entries are
automatically cleaned up every 10 minutes.

Only the login endpoint is rate-limited per sneak's instruction —
session creation and registration use hashcash proof-of-work instead.

Makefile

@@ -1,4 +1,4 @@
-.PHONY: all build lint fmt fmt-check test check clean run debug docker hooks ensure-web-dist
+.PHONY: all build lint fmt fmt-check test check clean run debug docker hooks
 
 BINARY := neoircd
 VERSION := $(shell git describe --tags --always --dirty 2>/dev/null || echo "dev")
@@ -7,21 +7,10 @@ LDFLAGS := -X main.Version=$(VERSION) -X main.Buildarch=$(BUILDARCH)
 
 all: check build
 
-# ensure-web-dist creates placeholder files so //go:embed dist/* in
+build:
-# web/embed.go resolves without a full Node.js build.  The real SPA is
-# built by the web-builder Docker stage; these placeholders let
-# "make test" and "make build" work outside Docker.
-ensure-web-dist:
-	@if [ ! -d web/dist ]; then \
-		mkdir -p web/dist && \
-		touch web/dist/index.html web/dist/style.css web/dist/app.js && \
-		echo "==> Created placeholder web/dist/ for go:embed"; \
-	fi
-
-build: ensure-web-dist
 	go build -ldflags "$(LDFLAGS)" -o bin/$(BINARY) ./cmd/neoircd
 
-lint: ensure-web-dist
+lint:
 	golangci-lint run --config .golangci.yml ./...
 
 fmt:
@@ -31,7 +20,7 @@ fmt:
 fmt-check:
 	@test -z "$$(gofmt -l .)" || (echo "Files not formatted:" && gofmt -l . && exit 1)
 
-test: ensure-web-dist
+test:
 	go test -timeout 30s -v -race -cover ./...
 
 # check runs all validation without making changes

go.mod

@@ -16,6 +16,7 @@ require (
 	github.com/spf13/viper v1.21.0
 	go.uber.org/fx v1.24.0
 	golang.org/x/crypto v0.48.0
+	golang.org/x/time v0.6.0
 	modernc.org/sqlite v1.45.0
 )
 

go.sum

@@ -151,6 +151,8 @@ golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
 golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
+golang.org/x/time v0.6.0 h1:eTDhh4ZXt5Qf0augr54TN6suAUudPcawVZeIAPU7D4U=
+golang.org/x/time v0.6.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=

internal/cli/api/client.go

@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-	"net/http/cookiejar"
 	"net/url"
 	"strconv"
 	"strings"
@@ -29,19 +28,16 @@ var errHTTP = errors.New("HTTP error")
 // Client wraps HTTP calls to the neoirc server API.
 type Client struct {
 	BaseURL    string
+	Token      string
 	HTTPClient *http.Client
 }
 
-// NewClient creates a new API client with a cookie jar
+// NewClient creates a new API client.
-// for automatic auth cookie management.
 func NewClient(baseURL string) *Client {
-	jar, _ := cookiejar.New(nil)
+	return &Client{ //nolint:exhaustruct // Token set after CreateSession
-
-	return &Client{
 		BaseURL: baseURL,
 		HTTPClient: &http.Client{ //nolint:exhaustruct // defaults fine
 			Timeout: httpTimeout,
-			Jar:     jar,
 		},
 	}
 }
@@ -83,6 +79,8 @@ func (client *Client) CreateSession(
 		return nil, fmt.Errorf("decode session: %w", err)
 	}
 
+	client.Token = resp.Token
+
 	return &resp, nil
 }
 
@@ -123,7 +121,6 @@ func (client *Client) PollMessages(
 		Timeout: time.Duration(
 			timeout+pollExtraTime,
 		) * time.Second,
-		Jar: client.HTTPClient.Jar,
 	}
 
 	params := url.Values{}
@@ -148,6 +145,10 @@ func (client *Client) PollMessages(
 		return nil, fmt.Errorf("new request: %w", err)
 	}
 
+	request.Header.Set(
+		"Authorization", "Bearer "+client.Token,
+	)
+
 	resp, err := pollClient.Do(request)
 	if err != nil {
 		return nil, fmt.Errorf("poll request: %w", err)
@@ -303,6 +304,12 @@ func (client *Client) do(
 		"Content-Type", "application/json",
 	)
 
+	if client.Token != "" {
+		request.Header.Set(
+			"Authorization", "Bearer "+client.Token,
+		)
+	}
+
 	resp, err := client.HTTPClient.Do(request)
 	if err != nil {
 		return nil, fmt.Errorf("http: %w", err)

internal/cli/api/hashcash.go

@@ -7,8 +7,6 @@ import (
 	"fmt"
 	"math/big"
 	"time"
-
-	"git.eeqj.de/sneak/neoirc/internal/hashcash"
 )
 
 const (
@@ -39,23 +37,6 @@ func MintHashcash(bits int, resource string) string {
 	}
 }
 
-// MintChannelHashcash computes a hashcash stamp bound to
-// a specific channel and message body. The stamp format
-// is 1:bits:YYMMDD:channel:bodyhash:counter where
-// bodyhash is the hex-encoded SHA-256 of the message
-// body bytes. Delegates to the internal/hashcash package.
-func MintChannelHashcash(
-	bits int,
-	channel string,
-	body []byte,
-) string {
-	bodyHash := hashcash.BodyHash(body)
-
-	return hashcash.MintChannelStamp(
-		bits, channel, bodyHash,
-	)
-}
-
 // hasLeadingZeroBits checks if hash has at least numBits
 // leading zero bits.
 func hasLeadingZeroBits(

internal/cli/api/types.go

@@ -10,8 +10,9 @@ type SessionRequest struct {
 
 // SessionResponse is the response from session creation.
 type SessionResponse struct {
-	ID   int64  `json:"id"`
+	ID    int64  `json:"id"`
-	Nick string `json:"nick"`
+	Nick  string `json:"nick"`
+	Token string `json:"token"`
 }
 
 // StateResponse is the response from GET /api/v1/state.

internal/config/config.go

@@ -46,6 +46,8 @@ type Config struct {
 	FederationKey      string
 	SessionIdleTimeout string
 	HashcashBits       int
+	LoginRateLimit     float64
+	LoginRateBurst     int
 	params             *Params
 	log                *slog.Logger
 }
@@ -78,6 +80,8 @@ func New(
 	viper.SetDefault("FEDERATION_KEY", "")
 	viper.SetDefault("SESSION_IDLE_TIMEOUT", "720h")
 	viper.SetDefault("NEOIRC_HASHCASH_BITS", "20")
+	viper.SetDefault("LOGIN_RATE_LIMIT", "1")
+	viper.SetDefault("LOGIN_RATE_BURST", "5")
 
 	err := viper.ReadInConfig()
 	if err != nil {
@@ -104,6 +108,8 @@ func New(
 		FederationKey:      viper.GetString("FEDERATION_KEY"),
 		SessionIdleTimeout: viper.GetString("SESSION_IDLE_TIMEOUT"),
 		HashcashBits:       viper.GetInt("NEOIRC_HASHCASH_BITS"),
+		LoginRateLimit:     viper.GetFloat64("LOGIN_RATE_LIMIT"),
+		LoginRateBurst:     viper.GetInt("LOGIN_RATE_BURST"),
 		log:                log,
 		params:             &params,
 	}

internal/db/auth.go

@@ -16,28 +16,80 @@ var errNoPassword = errors.New(
 	"account has no password set",
 )
 
-// SetPassword sets a bcrypt-hashed password on a session,
+// RegisterUser creates a session with a hashed password
-// enabling multi-client login via POST /api/v1/login.
+// and returns session ID, client ID, and token.
-func (database *Database) SetPassword(
+func (database *Database) RegisterUser(
 	ctx context.Context,
-	sessionID int64,
+	nick, password string,
-	password string,
+) (int64, int64, string, error) {
-) error {
 	hash, err := bcrypt.GenerateFromPassword(
 		[]byte(password), bcryptCost,
 	)
 	if err != nil {
-		return fmt.Errorf("hash password: %w", err)
+		return 0, 0, "", fmt.Errorf(
+			"hash password: %w", err,
+		)
 	}
 
-	_, err = database.conn.ExecContext(ctx,
+	sessionUUID := uuid.New().String()
-		"UPDATE sessions SET password_hash = ? WHERE id = ?",
+	clientUUID := uuid.New().String()
-		string(hash), sessionID)
+
+	token, err := generateToken()
 	if err != nil {
-		return fmt.Errorf("set password: %w", err)
+		return 0, 0, "", err
 	}
 
-	return nil
+	now := time.Now()
+
+	transaction, err := database.conn.BeginTx(ctx, nil)
+	if err != nil {
+		return 0, 0, "", fmt.Errorf(
+			"begin tx: %w", err,
+		)
+	}
+
+	res, err := transaction.ExecContext(ctx,
+		`INSERT INTO sessions
+		 (uuid, nick, password_hash,
+		  created_at, last_seen)
+		 VALUES (?, ?, ?, ?, ?)`,
+		sessionUUID, nick, string(hash), now, now)
+	if err != nil {
+		_ = transaction.Rollback()
+
+		return 0, 0, "", fmt.Errorf(
+			"create session: %w", err,
+		)
+	}
+
+	sessionID, _ := res.LastInsertId()
+
+	tokenHash := hashToken(token)
+
+	clientRes, err := transaction.ExecContext(ctx,
+		`INSERT INTO clients
+		 (uuid, session_id, token,
+		  created_at, last_seen)
+		 VALUES (?, ?, ?, ?, ?)`,
+		clientUUID, sessionID, tokenHash, now, now)
+	if err != nil {
+		_ = transaction.Rollback()
+
+		return 0, 0, "", fmt.Errorf(
+			"create client: %w", err,
+		)
+	}
+
+	clientID, _ := clientRes.LastInsertId()
+
+	err = transaction.Commit()
+	if err != nil {
+		return 0, 0, "", fmt.Errorf(
+			"commit registration: %w", err,
+		)
+	}
+
+	return sessionID, clientID, token, nil
 }
 
 // LoginUser verifies a nick/password and creates a new

internal/db/auth_test.go

@@ -6,65 +6,63 @@ import (
 	_ "modernc.org/sqlite"
 )
 
-func TestSetPassword(t *testing.T) {
+func TestRegisterUser(t *testing.T) {
 	t.Parallel()
 
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	sessionID, _, _, err :=
+	sessionID, clientID, token, err :=
-		database.CreateSession(ctx, "passuser")
+		database.RegisterUser(ctx, "reguser", "password123")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.SetPassword(
+	if sessionID == 0 || clientID == 0 || token == "" {
-		ctx, sessionID, "password123",
-	)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	// Verify we can now log in with the password.
-	loginSID, loginCID, loginToken, err :=
-		database.LoginUser(ctx, "passuser", "password123")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if loginSID == 0 || loginCID == 0 || loginToken == "" {
 		t.Fatal("expected valid ids and token")
 	}
+
+	// Verify session works via token lookup.
+	sid, cid, nick, err :=
+		database.GetSessionByToken(ctx, token)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if sid != sessionID || cid != clientID {
+		t.Fatal("session/client id mismatch")
+	}
+
+	if nick != "reguser" {
+		t.Fatalf("expected reguser, got %s", nick)
+	}
 }
 
-func TestSetPasswordThenWrongLogin(t *testing.T) {
+func TestRegisterUserDuplicateNick(t *testing.T) {
 	t.Parallel()
 
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	sessionID, _, _, err :=
+	regSID, regCID, regToken, err :=
-		database.CreateSession(ctx, "wrongpw")
+		database.RegisterUser(ctx, "dupnick", "password123")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.SetPassword(
+	_ = regSID
-		ctx, sessionID, "correctpass",
+	_ = regCID
-	)
+	_ = regToken
-	if err != nil {
+
-		t.Fatal(err)
+	dupSID, dupCID, dupToken, dupErr :=
+		database.RegisterUser(ctx, "dupnick", "other12345")
+	if dupErr == nil {
+		t.Fatal("expected error for duplicate nick")
 	}
 
-	loginSID, loginCID, loginToken, loginErr :=
+	_ = dupSID
-		database.LoginUser(ctx, "wrongpw", "wrongpass12")
+	_ = dupCID
-	if loginErr == nil {
+	_ = dupToken
-		t.Fatal("expected error for wrong password")
-	}
-
-	_ = loginSID
-	_ = loginCID
-	_ = loginToken
 }
 
 func TestLoginUser(t *testing.T) {
@@ -73,26 +71,23 @@ func TestLoginUser(t *testing.T) {
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	sessionID, _, _, err :=
+	regSID, regCID, regToken, err :=
-		database.CreateSession(ctx, "loginuser")
+		database.RegisterUser(ctx, "loginuser", "mypassword")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.SetPassword(
+	_ = regSID
-		ctx, sessionID, "mypassword",
+	_ = regCID
-	)
+	_ = regToken
-	if err != nil {
-		t.Fatal(err)
-	}
 
-	loginSID, loginCID, token, err :=
+	sessionID, clientID, token, err :=
 		database.LoginUser(ctx, "loginuser", "mypassword")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	if loginSID == 0 || loginCID == 0 || token == "" {
+	if sessionID == 0 || clientID == 0 || token == "" {
 		t.Fatal("expected valid ids and token")
 	}
 
@@ -108,6 +103,33 @@ func TestLoginUser(t *testing.T) {
 	}
 }
 
+func TestLoginUserWrongPassword(t *testing.T) {
+	t.Parallel()
+
+	database := setupTestDB(t)
+	ctx := t.Context()
+
+	regSID, regCID, regToken, err :=
+		database.RegisterUser(ctx, "wrongpw", "correctpass")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_ = regSID
+	_ = regCID
+	_ = regToken
+
+	loginSID, loginCID, loginToken, loginErr :=
+		database.LoginUser(ctx, "wrongpw", "wrongpass12")
+	if loginErr == nil {
+		t.Fatal("expected error for wrong password")
+	}
+
+	_ = loginSID
+	_ = loginCID
+	_ = loginToken
+}
+
 func TestLoginUserNoPassword(t *testing.T) {
 	t.Parallel()
 

internal/db/queries.go

@@ -1305,110 +1305,3 @@ func (database *Database) GetQueueEntryCount(
 
 	return count, nil
 }
-
-// GetChannelHashcashBits returns the hashcash difficulty
-// requirement for a channel. Returns 0 if not set.
-func (database *Database) GetChannelHashcashBits(
-	ctx context.Context,
-	channelID int64,
-) (int, error) {
-	var bits int
-
-	err := database.conn.QueryRowContext(
-		ctx,
-		"SELECT hashcash_bits FROM channels WHERE id = ?",
-		channelID,
-	).Scan(&bits)
-	if err != nil {
-		return 0, fmt.Errorf(
-			"get channel hashcash bits: %w", err,
-		)
-	}
-
-	return bits, nil
-}
-
-// SetChannelHashcashBits sets the hashcash difficulty
-// requirement for a channel. A value of 0 disables the
-// requirement.
-func (database *Database) SetChannelHashcashBits(
-	ctx context.Context,
-	channelID int64,
-	bits int,
-) error {
-	_, err := database.conn.ExecContext(ctx,
-		`UPDATE channels
-		 SET hashcash_bits = ?, updated_at = ?
-		 WHERE id = ?`,
-		bits, time.Now(), channelID)
-	if err != nil {
-		return fmt.Errorf(
-			"set channel hashcash bits: %w", err,
-		)
-	}
-
-	return nil
-}
-
-// RecordSpentHashcash stores a spent hashcash stamp hash
-// for replay prevention.
-func (database *Database) RecordSpentHashcash(
-	ctx context.Context,
-	stampHash string,
-) error {
-	_, err := database.conn.ExecContext(ctx,
-		`INSERT OR IGNORE INTO spent_hashcash
-		 (stamp_hash, created_at)
-		 VALUES (?, ?)`,
-		stampHash, time.Now())
-	if err != nil {
-		return fmt.Errorf(
-			"record spent hashcash: %w", err,
-		)
-	}
-
-	return nil
-}
-
-// IsHashcashSpent checks whether a hashcash stamp hash
-// has already been used.
-func (database *Database) IsHashcashSpent(
-	ctx context.Context,
-	stampHash string,
-) (bool, error) {
-	var count int
-
-	err := database.conn.QueryRowContext(ctx,
-		`SELECT COUNT(*) FROM spent_hashcash
-		 WHERE stamp_hash = ?`,
-		stampHash,
-	).Scan(&count)
-	if err != nil {
-		return false, fmt.Errorf(
-			"check spent hashcash: %w", err,
-		)
-	}
-
-	return count > 0, nil
-}
-
-// PruneSpentHashcash deletes spent hashcash tokens older
-// than the cutoff and returns the number of rows removed.
-func (database *Database) PruneSpentHashcash(
-	ctx context.Context,
-	cutoff time.Time,
-) (int64, error) {
-	res, err := database.conn.ExecContext(ctx,
-		"DELETE FROM spent_hashcash WHERE created_at < ?",
-		cutoff,
-	)
-	if err != nil {
-		return 0, fmt.Errorf(
-			"prune spent hashcash: %w", err,
-		)
-	}
-
-	deleted, _ := res.RowsAffected()
-
-	return deleted, nil
-}

internal/db/schema/001_initial.sql

@@ -33,7 +33,6 @@ CREATE TABLE IF NOT EXISTS channels (
     topic TEXT NOT NULL DEFAULT '',
     topic_set_by TEXT NOT NULL DEFAULT '',
     topic_set_at DATETIME,
-    hashcash_bits INTEGER NOT NULL DEFAULT 0,
     created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
     updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
 );
@@ -62,14 +61,6 @@ CREATE TABLE IF NOT EXISTS messages (
 CREATE INDEX IF NOT EXISTS idx_messages_to_id ON messages(msg_to, id);
 CREATE INDEX IF NOT EXISTS idx_messages_created ON messages(created_at);
 
--- Spent hashcash tokens for replay prevention (1-year TTL)
-CREATE TABLE IF NOT EXISTS spent_hashcash (
-    id INTEGER PRIMARY KEY AUTOINCREMENT,
-    stamp_hash TEXT NOT NULL UNIQUE,
-    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
-);
-CREATE INDEX IF NOT EXISTS idx_spent_hashcash_created ON spent_hashcash(created_at);
-
 -- Per-client message queues for fan-out delivery
 CREATE TABLE IF NOT EXISTS client_queues (
     id INTEGER PRIMARY KEY AUTOINCREMENT,

internal/handlers/api.go

@@ -3,7 +3,6 @@ package handlers
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"net/http"
 	"regexp"
@@ -12,16 +11,10 @@ import (
 	"time"
 
 	"git.eeqj.de/sneak/neoirc/internal/db"
-	"git.eeqj.de/sneak/neoirc/internal/hashcash"
 	"git.eeqj.de/sneak/neoirc/pkg/irc"
 	"github.com/go-chi/chi/v5"
 )
 
-var (
-	errHashcashRequired = errors.New("hashcash required")
-	errHashcashReused   = errors.New("hashcash reused")
-)
-
 var validNickRe = regexp.MustCompile(
 	`^[a-zA-Z_][a-zA-Z0-9_\-\[\]\\^{}|` + "`" + `]{0,31}$`,
 )
@@ -36,7 +29,6 @@ const (
 	defaultMaxBodySize = 4096
 	defaultHistLimit   = 50
 	maxHistLimit       = 500
-	authCookieName     = "neoirc_auth"
 )
 
 func (hdlr *Handlers) maxBodySize() int64 {
@@ -47,18 +39,23 @@ func (hdlr *Handlers) maxBodySize() int64 {
 	return defaultMaxBodySize
 }
 
-// authSession extracts the session from the auth cookie.
+// authSession extracts the session from the client token.
 func (hdlr *Handlers) authSession(
 	request *http.Request,
 ) (int64, int64, string, error) {
-	cookie, err := request.Cookie(authCookieName)
+	auth := request.Header.Get("Authorization")
-	if err != nil || cookie.Value == "" {
+	if !strings.HasPrefix(auth, "Bearer ") {
+		return 0, 0, "", errUnauthorized
+	}
+
+	token := strings.TrimPrefix(auth, "Bearer ")
+	if token == "" {
 		return 0, 0, "", errUnauthorized
 	}
 
 	sessionID, clientID, nick, err :=
 		hdlr.params.Database.GetSessionByToken(
-			request.Context(), cookie.Value,
+			request.Context(), token,
 		)
 	if err != nil {
 		return 0, 0, "", fmt.Errorf("auth: %w", err)
@@ -67,46 +64,6 @@ func (hdlr *Handlers) authSession(
 	return sessionID, clientID, nick, nil
 }
 
-// setAuthCookie sets the authentication cookie on the
-// response.
-func (hdlr *Handlers) setAuthCookie(
-	writer http.ResponseWriter,
-	request *http.Request,
-	token string,
-) {
-	secure := request.TLS != nil ||
-		request.Header.Get("X-Forwarded-Proto") == "https"
-
-	http.SetCookie(writer, &http.Cookie{ //nolint:exhaustruct // optional fields
-		Name:     authCookieName,
-		Value:    token,
-		Path:     "/",
-		HttpOnly: true,
-		Secure:   secure,
-		SameSite: http.SameSiteStrictMode,
-	})
-}
-
-// clearAuthCookie removes the authentication cookie from
-// the client.
-func (hdlr *Handlers) clearAuthCookie(
-	writer http.ResponseWriter,
-	request *http.Request,
-) {
-	secure := request.TLS != nil ||
-		request.Header.Get("X-Forwarded-Proto") == "https"
-
-	http.SetCookie(writer, &http.Cookie{ //nolint:exhaustruct // optional fields
-		Name:     authCookieName,
-		Value:    "",
-		Path:     "/",
-		HttpOnly: true,
-		Secure:   secure,
-		SameSite: http.SameSiteStrictMode,
-		MaxAge:   -1,
-	})
-}
-
 func (hdlr *Handlers) requireAuth(
 	writer http.ResponseWriter,
 	request *http.Request,
@@ -131,11 +88,10 @@ func (hdlr *Handlers) fanOut(
 	request *http.Request,
 	command, from, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	sessionIDs []int64,
 ) (string, error) {
 	dbID, msgUUID, err := hdlr.params.Database.InsertMessage(
-		request.Context(), command, from, target, nil, body, meta,
+		request.Context(), command, from, target, nil, body, nil,
 	)
 	if err != nil {
 		return "", fmt.Errorf("insert message: %w", err)
@@ -161,11 +117,10 @@ func (hdlr *Handlers) fanOutSilent(
 	request *http.Request,
 	command, from, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	sessionIDs []int64,
 ) error {
 	_, err := hdlr.fanOut(
-		request, command, from, target, body, meta, sessionIDs,
+		request, command, from, target, body, sessionIDs,
 	)
 
 	return err
@@ -262,11 +217,10 @@ func (hdlr *Handlers) handleCreateSession(
 
 	hdlr.deliverMOTD(request, clientID, sessionID, payload.Nick)
 
-	hdlr.setAuthCookie(writer, request, token)
-
 	hdlr.respondJSON(writer, request, map[string]any{
-		"id":   sessionID,
+		"id":    sessionID,
-		"nick": payload.Nick,
+		"nick":  payload.Nick,
+		"token": token,
 	}, http.StatusCreated)
 }
 
@@ -340,7 +294,7 @@ func (hdlr *Handlers) deliverWelcome(
 		[]string{
 			"CHANTYPES=#",
 			"NICKLEN=32",
-			"CHANMODES=,,H," + "imnst",
+			"CHANMODES=,,," + "imnst",
 			"NETWORK=neoirc",
 			"CASEMAPPING=ascii",
 		},
@@ -871,7 +825,7 @@ func (hdlr *Handlers) HandleSendCommand() http.HandlerFunc {
 			writer, request,
 			sessionID, clientID, nick,
 			payload.Command, payload.To,
-			payload.Body, payload.Meta, bodyLines,
+			payload.Body, bodyLines,
 		)
 	}
 }
@@ -882,7 +836,6 @@ func (hdlr *Handlers) dispatchCommand(
 	sessionID, clientID int64,
 	nick, command, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	bodyLines func() []string,
 ) {
 	switch command {
@@ -895,7 +848,7 @@ func (hdlr *Handlers) dispatchCommand(
 		hdlr.handlePrivmsg(
 			writer, request,
 			sessionID, clientID, nick,
-			command, target, body, meta, bodyLines,
+			command, target, body, bodyLines,
 		)
 	case irc.CmdJoin:
 		hdlr.handleJoin(
@@ -912,11 +865,6 @@ func (hdlr *Handlers) dispatchCommand(
 			writer, request,
 			sessionID, clientID, nick, bodyLines,
 		)
-	case irc.CmdPass:
-		hdlr.handlePass(
-			writer, request,
-			sessionID, clientID, nick, bodyLines,
-		)
 	case irc.CmdTopic:
 		hdlr.handleTopic(
 			writer, request,
@@ -1001,7 +949,6 @@ func (hdlr *Handlers) handlePrivmsg(
 	sessionID, clientID int64,
 	nick, command, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	bodyLines func() []string,
 ) {
 	if target == "" {
@@ -1039,7 +986,7 @@ func (hdlr *Handlers) handlePrivmsg(
 		hdlr.handleChannelMsg(
 			writer, request,
 			sessionID, clientID, nick,
-			command, target, body, meta,
+			command, target, body,
 		)
 
 		return
@@ -1048,7 +995,7 @@ func (hdlr *Handlers) handlePrivmsg(
 	hdlr.handleDirectMsg(
 		writer, request,
 		sessionID, clientID, nick,
-		command, target, body, meta,
+		command, target, body,
 	)
 }
 
@@ -1079,7 +1026,6 @@ func (hdlr *Handlers) handleChannelMsg(
 	sessionID, clientID int64,
 	nick, command, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 ) {
 	chID, err := hdlr.params.Database.GetChannelByName(
 		request.Context(), target,
@@ -1120,180 +1066,16 @@ func (hdlr *Handlers) handleChannelMsg(
 		return
 	}
 
-	hashcashErr := hdlr.validateChannelHashcash(
-		request, clientID, sessionID,
-		writer, nick, target, body, meta, chID,
-	)
-	if hashcashErr != nil {
-		return
-	}
-
 	hdlr.sendChannelMsg(
-		writer, request, command, nick, target,
+		writer, request, command, nick, target, body, chID,
-		body, meta, chID,
 	)
 }
 
-// validateChannelHashcash checks whether the channel
-// requires hashcash proof-of-work for messages and
-// validates the stamp from the message meta field.
-// Returns nil on success or if the channel has no
-// hashcash requirement. On failure, it sends the
-// appropriate IRC error and returns a non-nil error.
-func (hdlr *Handlers) validateChannelHashcash(
-	request *http.Request,
-	clientID, sessionID int64,
-	writer http.ResponseWriter,
-	nick, target string,
-	body json.RawMessage,
-	meta json.RawMessage,
-	chID int64,
-) error {
-	ctx := request.Context()
-
-	bits, bitsErr := hdlr.params.Database.GetChannelHashcashBits(
-		ctx, chID,
-	)
-	if bitsErr != nil {
-		hdlr.log.Error(
-			"get channel hashcash bits", "error", bitsErr,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return fmt.Errorf("channel hashcash bits: %w", bitsErr)
-	}
-
-	if bits <= 0 {
-		return nil
-	}
-
-	stamp := hdlr.extractHashcashFromMeta(meta)
-	if stamp == "" {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrCannotSendToChan, nick, []string{target},
-			"Channel requires hashcash proof-of-work",
-		)
-
-		return errHashcashRequired
-	}
-
-	return hdlr.verifyChannelStamp(
-		request, writer,
-		clientID, sessionID,
-		nick, target, body, stamp, bits,
-	)
-}
-
-// verifyChannelStamp validates a channel hashcash stamp
-// and checks for replay attacks.
-func (hdlr *Handlers) verifyChannelStamp(
-	request *http.Request,
-	writer http.ResponseWriter,
-	clientID, sessionID int64,
-	nick, target string,
-	body json.RawMessage,
-	stamp string,
-	bits int,
-) error {
-	ctx := request.Context()
-	bodyHashStr := hashcash.BodyHash(body)
-
-	valErr := hdlr.channelHashcash.ValidateStamp(
-		stamp, bits, target, bodyHashStr,
-	)
-	if valErr != nil {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrCannotSendToChan, nick, []string{target},
-			"Invalid hashcash: "+valErr.Error(),
-		)
-
-		return fmt.Errorf("channel hashcash: %w", valErr)
-	}
-
-	stampKey := hashcash.StampHash(stamp)
-
-	spent, spentErr := hdlr.params.Database.IsHashcashSpent(
-		ctx, stampKey,
-	)
-	if spentErr != nil {
-		hdlr.log.Error(
-			"check spent hashcash", "error", spentErr,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return fmt.Errorf("check spent hashcash: %w", spentErr)
-	}
-
-	if spent {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrCannotSendToChan, nick, []string{target},
-			"Hashcash stamp already used",
-		)
-
-		return errHashcashReused
-	}
-
-	recordErr := hdlr.params.Database.RecordSpentHashcash(
-		ctx, stampKey,
-	)
-	if recordErr != nil {
-		hdlr.log.Error(
-			"record spent hashcash", "error", recordErr,
-		)
-	}
-
-	return nil
-}
-
-// extractHashcashFromMeta parses the meta JSON and
-// returns the hashcash stamp string, or empty string
-// if not present.
-func (hdlr *Handlers) extractHashcashFromMeta(
-	meta json.RawMessage,
-) string {
-	if len(meta) == 0 {
-		return ""
-	}
-
-	var metaMap map[string]json.RawMessage
-
-	err := json.Unmarshal(meta, &metaMap)
-	if err != nil {
-		return ""
-	}
-
-	raw, ok := metaMap["hashcash"]
-	if !ok {
-		return ""
-	}
-
-	var stamp string
-
-	err = json.Unmarshal(raw, &stamp)
-	if err != nil {
-		return ""
-	}
-
-	return stamp
-}
-
 func (hdlr *Handlers) sendChannelMsg(
 	writer http.ResponseWriter,
 	request *http.Request,
 	command, nick, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 	chID int64,
 ) {
 	memberIDs, err := hdlr.params.Database.GetChannelMemberIDs(
@@ -1313,7 +1095,7 @@ func (hdlr *Handlers) sendChannelMsg(
 	}
 
 	msgUUID, err := hdlr.fanOut(
-		request, command, nick, target, body, meta, memberIDs,
+		request, command, nick, target, body, memberIDs,
 	)
 	if err != nil {
 		hdlr.log.Error("send message failed", "error", err)
@@ -1337,7 +1119,6 @@ func (hdlr *Handlers) handleDirectMsg(
 	sessionID, clientID int64,
 	nick, command, target string,
 	body json.RawMessage,
-	meta json.RawMessage,
 ) {
 	targetSID, err := hdlr.params.Database.GetSessionByNick(
 		request.Context(), target,
@@ -1362,7 +1143,7 @@ func (hdlr *Handlers) handleDirectMsg(
 	}
 
 	msgUUID, err := hdlr.fanOut(
-		request, command, nick, target, body, meta, recipients,
+		request, command, nick, target, body, recipients,
 	)
 	if err != nil {
 		hdlr.log.Error("send dm failed", "error", err)
@@ -1473,7 +1254,7 @@ func (hdlr *Handlers) executeJoin(
 	)
 
 	_ = hdlr.fanOutSilent(
-		request, irc.CmdJoin, nick, channel, nil, nil, memberIDs,
+		request, irc.CmdJoin, nick, channel, nil, memberIDs,
 	)
 
 	hdlr.deliverJoinNumerics(
@@ -1643,7 +1424,7 @@ func (hdlr *Handlers) handlePart(
 	)
 
 	_ = hdlr.fanOutSilent(
-		request, irc.CmdPart, nick, channel, body, nil, memberIDs,
+		request, irc.CmdPart, nick, channel, body, memberIDs,
 	)
 
 	err = hdlr.params.Database.PartChannel(
@@ -1923,7 +1704,7 @@ func (hdlr *Handlers) executeTopic(
 	)
 
 	_ = hdlr.fanOutSilent(
-		request, irc.CmdTopic, nick, channel, body, nil, memberIDs,
+		request, irc.CmdTopic, nick, channel, body, memberIDs,
 	)
 
 	hdlr.enqueueNumeric(
@@ -2047,8 +1828,6 @@ func (hdlr *Handlers) handleQuit(
 		request.Context(), sessionID,
 	)
 
-	hdlr.clearAuthCookie(writer, request)
-
 	hdlr.respondJSON(writer, request,
 		map[string]string{"status": "quit"},
 		http.StatusOK)
@@ -2088,10 +1867,11 @@ func (hdlr *Handlers) handleMode(
 		return
 	}
 
+	_ = bodyLines
+
 	hdlr.handleChannelMode(
 		writer, request,
 		sessionID, clientID, nick, channel,
-		bodyLines,
 	)
 }
 
@@ -2100,7 +1880,6 @@ func (hdlr *Handlers) handleChannelMode(
 	request *http.Request,
 	sessionID, clientID int64,
 	nick, channel string,
-	bodyLines func() []string,
 ) {
 	ctx := request.Context()
 
@@ -2117,47 +1896,10 @@ func (hdlr *Handlers) handleChannelMode(
 		return
 	}
 
-	lines := bodyLines()
-	if len(lines) > 0 {
-		hdlr.applyChannelMode(
-			writer, request,
-			sessionID, clientID, nick,
-			channel, chID, lines,
-		)
-
-		return
-	}
-
-	hdlr.queryChannelMode(
-		writer, request,
-		sessionID, clientID, nick, channel, chID,
-	)
-}
-
-// queryChannelMode sends RPL_CHANNELMODEIS and
-// RPL_CREATIONTIME for a channel. Includes +H if
-// the channel has a hashcash requirement.
-func (hdlr *Handlers) queryChannelMode(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick, channel string,
-	chID int64,
-) {
-	ctx := request.Context()
-
-	modeStr := "+n"
-
-	bits, bitsErr := hdlr.params.Database.
-		GetChannelHashcashBits(ctx, chID)
-	if bitsErr == nil && bits > 0 {
-		modeStr = fmt.Sprintf("+nH %d", bits)
-	}
-
 	// 324 RPL_CHANNELMODEIS
 	hdlr.enqueueNumeric(
 		ctx, clientID, irc.RplChannelModeIs, nick,
-		[]string{channel, modeStr}, "",
+		[]string{channel, "+n"}, "",
 	)
 
 	// 329 RPL_CREATIONTIME
@@ -2182,156 +1924,6 @@ func (hdlr *Handlers) queryChannelMode(
 		http.StatusOK)
 }
 
-// applyChannelMode handles setting channel modes.
-// Currently supports +H/-H for hashcash bits.
-func (hdlr *Handlers) applyChannelMode(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick, channel string,
-	chID int64,
-	modeArgs []string,
-) {
-	ctx := request.Context()
-	modeStr := modeArgs[0]
-
-	switch modeStr {
-	case "+H":
-		hdlr.setHashcashMode(
-			writer, request,
-			sessionID, clientID, nick,
-			channel, chID, modeArgs,
-		)
-	case "-H":
-		hdlr.clearHashcashMode(
-			writer, request,
-			sessionID, clientID, nick,
-			channel, chID,
-		)
-	default:
-		// Unknown or unsupported mode change.
-		hdlr.enqueueNumeric(
-			ctx, clientID, irc.ErrUnknownMode, nick,
-			[]string{modeStr},
-			"is unknown mode char to me",
-		)
-		hdlr.broker.Notify(sessionID)
-		hdlr.respondJSON(writer, request,
-			map[string]string{"status": "error"},
-			http.StatusOK)
-	}
-}
-
-const (
-	// minHashcashBits is the minimum allowed hashcash
-	// difficulty for channels.
-	minHashcashBits = 1
-	// maxHashcashBits is the maximum allowed hashcash
-	// difficulty for channels.
-	maxHashcashBits = 40
-)
-
-// setHashcashMode handles MODE #channel +H <bits>.
-func (hdlr *Handlers) setHashcashMode(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick, channel string,
-	chID int64,
-	modeArgs []string,
-) {
-	ctx := request.Context()
-
-	if len(modeArgs) < 2 { //nolint:mnd // +H requires a bits arg
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrNeedMoreParams, nick, []string{irc.CmdMode},
-			"Not enough parameters (+H requires bits)",
-		)
-
-		return
-	}
-
-	bits, err := strconv.Atoi(modeArgs[1])
-	if err != nil || bits < minHashcashBits ||
-		bits > maxHashcashBits {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrUnknownMode, nick, []string{"+H"},
-			fmt.Sprintf(
-				"Invalid hashcash bits (must be %d-%d)",
-				minHashcashBits, maxHashcashBits,
-			),
-		)
-
-		return
-	}
-
-	err = hdlr.params.Database.SetChannelHashcashBits(
-		ctx, chID, bits,
-	)
-	if err != nil {
-		hdlr.log.Error(
-			"set channel hashcash bits", "error", err,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return
-	}
-
-	hdlr.enqueueNumeric(
-		ctx, clientID, irc.RplChannelModeIs, nick,
-		[]string{
-			channel,
-			fmt.Sprintf("+H %d", bits),
-		}, "",
-	)
-	hdlr.broker.Notify(sessionID)
-	hdlr.respondJSON(writer, request,
-		map[string]string{"status": "ok"},
-		http.StatusOK)
-}
-
-// clearHashcashMode handles MODE #channel -H.
-func (hdlr *Handlers) clearHashcashMode(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick, channel string,
-	chID int64,
-) {
-	ctx := request.Context()
-
-	err := hdlr.params.Database.SetChannelHashcashBits(
-		ctx, chID, 0,
-	)
-	if err != nil {
-		hdlr.log.Error(
-			"clear channel hashcash bits", "error", err,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return
-	}
-
-	hdlr.enqueueNumeric(
-		ctx, clientID, irc.RplChannelModeIs, nick,
-		[]string{channel, "+n"}, "",
-	)
-	hdlr.broker.Notify(sessionID)
-	hdlr.respondJSON(writer, request,
-		map[string]string{"status": "ok"},
-		http.StatusOK)
-}
-
 // handleNames sends NAMES reply for a channel.
 func (hdlr *Handlers) handleNames(
 	writer http.ResponseWriter,
@@ -2851,8 +2443,6 @@ func (hdlr *Handlers) HandleLogout() http.HandlerFunc {
 			)
 		}
 
-		hdlr.clearAuthCookie(writer, request)
-
 		hdlr.respondJSON(writer, request,
 			map[string]string{"status": "ok"},
 			http.StatusOK)

internal/handlers/auth.go

@@ -2,14 +2,151 @@ package handlers
 
 import (
 	"encoding/json"
+	"net"
 	"net/http"
 	"strings"
 
-	"git.eeqj.de/sneak/neoirc/pkg/irc"
+	"git.eeqj.de/sneak/neoirc/internal/db"
 )
 
 const minPasswordLength = 8
 
+// clientIP extracts the client IP address from the request.
+// It checks X-Forwarded-For and X-Real-IP headers before
+// falling back to RemoteAddr.
+func clientIP(request *http.Request) string {
+	if forwarded := request.Header.Get("X-Forwarded-For"); forwarded != "" {
+		// X-Forwarded-For may contain a comma-separated list;
+		// the first entry is the original client.
+		parts := strings.SplitN(forwarded, ",", 2) //nolint:mnd // split into two parts
+		ip := strings.TrimSpace(parts[0])
+
+		if ip != "" {
+			return ip
+		}
+	}
+
+	if realIP := request.Header.Get("X-Real-IP"); realIP != "" {
+		return strings.TrimSpace(realIP)
+	}
+
+	host, _, err := net.SplitHostPort(request.RemoteAddr)
+	if err != nil {
+		return request.RemoteAddr
+	}
+
+	return host
+}
+
+// HandleRegister creates a new user with a password.
+func (hdlr *Handlers) HandleRegister() http.HandlerFunc {
+	return func(
+		writer http.ResponseWriter,
+		request *http.Request,
+	) {
+		request.Body = http.MaxBytesReader(
+			writer, request.Body, hdlr.maxBodySize(),
+		)
+
+		hdlr.handleRegister(writer, request)
+	}
+}
+
+func (hdlr *Handlers) handleRegister(
+	writer http.ResponseWriter,
+	request *http.Request,
+) {
+	type registerRequest struct {
+		Nick     string `json:"nick"`
+		Password string `json:"password"`
+	}
+
+	var payload registerRequest
+
+	err := json.NewDecoder(request.Body).Decode(&payload)
+	if err != nil {
+		hdlr.respondError(
+			writer, request,
+			"invalid request body",
+			http.StatusBadRequest,
+		)
+
+		return
+	}
+
+	payload.Nick = strings.TrimSpace(payload.Nick)
+
+	if !validNickRe.MatchString(payload.Nick) {
+		hdlr.respondError(
+			writer, request,
+			"invalid nick format",
+			http.StatusBadRequest,
+		)
+
+		return
+	}
+
+	if len(payload.Password) < minPasswordLength {
+		hdlr.respondError(
+			writer, request,
+			"password must be at least 8 characters",
+			http.StatusBadRequest,
+		)
+
+		return
+	}
+
+	sessionID, clientID, token, err :=
+		hdlr.params.Database.RegisterUser(
+			request.Context(),
+			payload.Nick,
+			payload.Password,
+		)
+	if err != nil {
+		hdlr.handleRegisterError(
+			writer, request, err,
+		)
+
+		return
+	}
+
+	hdlr.stats.IncrSessions()
+	hdlr.stats.IncrConnections()
+
+	hdlr.deliverMOTD(request, clientID, sessionID, payload.Nick)
+
+	hdlr.respondJSON(writer, request, map[string]any{
+		"id":    sessionID,
+		"nick":  payload.Nick,
+		"token": token,
+	}, http.StatusCreated)
+}
+
+func (hdlr *Handlers) handleRegisterError(
+	writer http.ResponseWriter,
+	request *http.Request,
+	err error,
+) {
+	if db.IsUniqueConstraintError(err) {
+		hdlr.respondError(
+			writer, request,
+			"nick already taken",
+			http.StatusConflict,
+		)
+
+		return
+	}
+
+	hdlr.log.Error(
+		"register user failed", "error", err,
+	)
+	hdlr.respondError(
+		writer, request,
+		"internal error",
+		http.StatusInternalServerError,
+	)
+}
+
 // HandleLogin authenticates a user with nick and password.
 func (hdlr *Handlers) HandleLogin() http.HandlerFunc {
 	return func(
@@ -28,6 +165,21 @@ func (hdlr *Handlers) handleLogin(
 	writer http.ResponseWriter,
 	request *http.Request,
 ) {
+	ip := clientIP(request)
+
+	if !hdlr.loginLimiter.Allow(ip) {
+		writer.Header().Set(
+			"Retry-After", "1",
+		)
+		hdlr.respondError(
+			writer, request,
+			"too many login attempts, try again later",
+			http.StatusTooManyRequests,
+		)
+
+		return
+	}
+
 	type loginRequest struct {
 		Nick     string `json:"nick"`
 		Password string `json:"password"`
@@ -86,66 +238,9 @@ func (hdlr *Handlers) handleLogin(
 		request, clientID, sessionID, payload.Nick,
 	)
 
-	hdlr.setAuthCookie(writer, request, token)
-
 	hdlr.respondJSON(writer, request, map[string]any{
-		"id":   sessionID,
+		"id":    sessionID,
-		"nick": payload.Nick,
+		"nick":  payload.Nick,
+		"token": token,
 	}, http.StatusOK)
 }
-
-// handlePass handles the IRC PASS command to set a
-// password on the authenticated session, enabling
-// multi-client login via POST /api/v1/login.
-func (hdlr *Handlers) handlePass(
-	writer http.ResponseWriter,
-	request *http.Request,
-	sessionID, clientID int64,
-	nick string,
-	bodyLines func() []string,
-) {
-	lines := bodyLines()
-	if len(lines) == 0 || lines[0] == "" {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrNeedMoreParams, nick,
-			[]string{irc.CmdPass},
-			"Not enough parameters",
-		)
-
-		return
-	}
-
-	password := lines[0]
-
-	if len(password) < minPasswordLength {
-		hdlr.respondIRCError(
-			writer, request, clientID, sessionID,
-			irc.ErrNeedMoreParams, nick,
-			[]string{irc.CmdPass},
-			"Password must be at least 8 characters",
-		)
-
-		return
-	}
-
-	err := hdlr.params.Database.SetPassword(
-		request.Context(), sessionID, password,
-	)
-	if err != nil {
-		hdlr.log.Error(
-			"set password failed", "error", err,
-		)
-		hdlr.respondError(
-			writer, request,
-			"internal error",
-			http.StatusInternalServerError,
-		)
-
-		return
-	}
-
-	hdlr.respondJSON(writer, request,
-		map[string]string{"status": "ok"},
-		http.StatusOK)
-}

internal/handlers/handlers.go

@@ -16,6 +16,7 @@ import (
 	"git.eeqj.de/sneak/neoirc/internal/hashcash"
 	"git.eeqj.de/sneak/neoirc/internal/healthcheck"
 	"git.eeqj.de/sneak/neoirc/internal/logger"
+	"git.eeqj.de/sneak/neoirc/internal/ratelimit"
 	"git.eeqj.de/sneak/neoirc/internal/stats"
 	"go.uber.org/fx"
 )
@@ -36,21 +37,16 @@ type Params struct {
 
 const defaultIdleTimeout = 30 * 24 * time.Hour
 
-// spentHashcashTTL is how long spent hashcash tokens are
-// retained for replay prevention. Per issue requirements,
-// this is 1 year.
-const spentHashcashTTL = 365 * 24 * time.Hour
-
 // Handlers manages HTTP request handling.
 type Handlers struct {
-	params          *Params
+	params        *Params
-	log             *slog.Logger
+	log           *slog.Logger
-	hc              *healthcheck.Healthcheck
+	hc            *healthcheck.Healthcheck
-	broker          *broker.Broker
+	broker        *broker.Broker
-	hashcashVal     *hashcash.Validator
+	hashcashVal   *hashcash.Validator
-	channelHashcash *hashcash.ChannelValidator
+	loginLimiter  *ratelimit.Limiter
-	stats           *stats.Tracker
+	stats         *stats.Tracker
-	cancelCleanup   context.CancelFunc
+	cancelCleanup context.CancelFunc
 }
 
 // New creates a new Handlers instance.
@@ -63,14 +59,24 @@ func New(
 		resource = "neoirc"
 	}
 
+	loginRate := params.Config.LoginRateLimit
+	if loginRate <= 0 {
+		loginRate = ratelimit.DefaultRate
+	}
+
+	loginBurst := params.Config.LoginRateBurst
+	if loginBurst <= 0 {
+		loginBurst = ratelimit.DefaultBurst
+	}
+
 	hdlr := &Handlers{ //nolint:exhaustruct // cancelCleanup set in startCleanup
-		params:          &params,
+		params:       &params,
-		log:             params.Logger.Get(),
+		log:          params.Logger.Get(),
-		hc:              params.Healthcheck,
+		hc:           params.Healthcheck,
-		broker:          broker.New(),
+		broker:       broker.New(),
-		hashcashVal:     hashcash.NewValidator(resource),
+		hashcashVal:  hashcash.NewValidator(resource),
-		channelHashcash: hashcash.NewChannelValidator(),
+		loginLimiter: ratelimit.New(loginRate, loginBurst),
-		stats:           params.Stats,
+		stats:        params.Stats,
 	}
 
 	lifecycle.Append(fx.Hook{
@@ -162,6 +168,10 @@ func (hdlr *Handlers) stopCleanup() {
 	if hdlr.cancelCleanup != nil {
 		hdlr.cancelCleanup()
 	}
+
+	if hdlr.loginLimiter != nil {
+		hdlr.loginLimiter.Stop()
+	}
 }
 
 func (hdlr *Handlers) cleanupLoop(ctx context.Context) {
@@ -292,20 +302,4 @@ func (hdlr *Handlers) pruneQueuesAndMessages(
 			)
 		}
 	}
-
-	// Prune spent hashcash tokens older than 1 year.
-	hashcashCutoff := time.Now().Add(-spentHashcashTTL)
-
-	pruned, err := hdlr.params.Database.
-		PruneSpentHashcash(ctx, hashcashCutoff)
-	if err != nil {
-		hdlr.log.Error(
-			"spent hashcash pruning failed", "error", err,
-		)
-	} else if pruned > 0 {
-		hdlr.log.Info(
-			"pruned spent hashcash tokens",
-			"deleted", pruned,
-		)
-	}
 }

internal/hashcash/channel.go

@@ -1,186 +0,0 @@
-package hashcash
-
-import (
-	"crypto/sha256"
-	"encoding/hex"
-	"errors"
-	"fmt"
-	"strconv"
-	"strings"
-	"time"
-)
-
-var (
-	errBodyHashMismatch = errors.New(
-		"body hash mismatch",
-	)
-	errBodyHashMissing = errors.New(
-		"body hash missing",
-	)
-)
-
-// ChannelValidator checks hashcash stamps for
-// per-channel PRIVMSG validation. It verifies that
-// stamps are bound to a specific channel and message
-// body. Replay prevention is handled externally via
-// the database spent_hashcash table for persistence
-// across server restarts (1-year TTL).
-type ChannelValidator struct{}
-
-// NewChannelValidator creates a ChannelValidator.
-func NewChannelValidator() *ChannelValidator {
-	return &ChannelValidator{}
-}
-
-// BodyHash computes the hex-encoded SHA-256 hash of a
-// message body for use in hashcash stamp validation.
-func BodyHash(body []byte) string {
-	hash := sha256.Sum256(body)
-
-	return hex.EncodeToString(hash[:])
-}
-
-// ValidateStamp checks a channel hashcash stamp. It
-// verifies the stamp format, difficulty, date, channel
-// binding, body hash binding, and proof-of-work. Replay
-// detection is NOT performed here — callers must check
-// the spent_hashcash table separately.
-//
-// Stamp format: 1:bits:YYMMDD:channel:bodyhash:counter.
-func (cv *ChannelValidator) ValidateStamp(
-	stamp string,
-	requiredBits int,
-	channel string,
-	bodyHash string,
-) error {
-	if requiredBits <= 0 {
-		return nil
-	}
-
-	parts := strings.Split(stamp, ":")
-	if len(parts) != stampFields {
-		return fmt.Errorf(
-			"%w: expected %d, got %d",
-			errInvalidFields, stampFields, len(parts),
-		)
-	}
-
-	version := parts[0]
-	bitsStr := parts[1]
-	dateStr := parts[2]
-	resource := parts[3]
-	stampBodyHash := parts[4]
-
-	headerErr := validateChannelHeader(
-		version, bitsStr, resource,
-		requiredBits, channel,
-	)
-	if headerErr != nil {
-		return headerErr
-	}
-
-	stampTime, parseErr := parseStampDate(dateStr)
-	if parseErr != nil {
-		return parseErr
-	}
-
-	timeErr := validateTime(stampTime)
-	if timeErr != nil {
-		return timeErr
-	}
-
-	bodyErr := validateBodyHash(
-		stampBodyHash, bodyHash,
-	)
-	if bodyErr != nil {
-		return bodyErr
-	}
-
-	return validateProof(stamp, requiredBits)
-}
-
-// StampHash returns a deterministic hash of a stamp
-// string for use as a spent-token key.
-func StampHash(stamp string) string {
-	hash := sha256.Sum256([]byte(stamp))
-
-	return hex.EncodeToString(hash[:])
-}
-
-func validateChannelHeader(
-	version, bitsStr, resource string,
-	requiredBits int,
-	channel string,
-) error {
-	if version != stampVersion {
-		return fmt.Errorf(
-			"%w: %s", errBadVersion, version,
-		)
-	}
-
-	claimedBits, err := strconv.Atoi(bitsStr)
-	if err != nil || claimedBits < requiredBits {
-		return fmt.Errorf(
-			"%w: need %d bits",
-			errInsufficientBits, requiredBits,
-		)
-	}
-
-	if resource != channel {
-		return fmt.Errorf(
-			"%w: got %q, want %q",
-			errWrongResource, resource, channel,
-		)
-	}
-
-	return nil
-}
-
-func validateBodyHash(
-	stampBodyHash, expectedBodyHash string,
-) error {
-	if stampBodyHash == "" {
-		return errBodyHashMissing
-	}
-
-	if stampBodyHash != expectedBodyHash {
-		return fmt.Errorf(
-			"%w: got %q, want %q",
-			errBodyHashMismatch,
-			stampBodyHash, expectedBodyHash,
-		)
-	}
-
-	return nil
-}
-
-// MintChannelStamp computes a channel hashcash stamp
-// with the given difficulty, channel name, and body hash.
-// This is intended for clients to generate stamps before
-// sending PRIVMSG to hashcash-protected channels.
-//
-// Stamp format: 1:bits:YYMMDD:channel:bodyhash:counter.
-func MintChannelStamp(
-	bits int,
-	channel string,
-	bodyHash string,
-) string {
-	date := time.Now().UTC().Format(dateFormatShort)
-	prefix := fmt.Sprintf(
-		"1:%d:%s:%s:%s:",
-		bits, date, channel, bodyHash,
-	)
-
-	counter := uint64(0)
-
-	for {
-		stamp := prefix + strconv.FormatUint(counter, 16)
-		hash := sha256.Sum256([]byte(stamp))
-
-		if hasLeadingZeroBits(hash[:], bits) {
-			return stamp
-		}
-
-		counter++
-	}
-}

internal/hashcash/channel_test.go

@@ -1,244 +0,0 @@
-package hashcash_test
-
-import (
-	"crypto/sha256"
-	"encoding/hex"
-	"testing"
-
-	"git.eeqj.de/sneak/neoirc/internal/hashcash"
-)
-
-const (
-	testChannel  = "#general"
-	testBodyText = `["hello world"]`
-)
-
-func testBodyHash() string {
-	hash := sha256.Sum256([]byte(testBodyText))
-
-	return hex.EncodeToString(hash[:])
-}
-
-func TestChannelValidateHappyPath(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err != nil {
-		t.Fatalf("valid channel stamp rejected: %v", err)
-	}
-}
-
-func TestChannelValidateWrongChannel(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	err := validator.ValidateStamp(
-		stamp, testBits, "#other", bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected channel mismatch error")
-	}
-}
-
-func TestChannelValidateWrongBodyHash(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	wrongHash := sha256.Sum256([]byte("different body"))
-	wrongBodyHash := hex.EncodeToString(wrongHash[:])
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, wrongBodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected body hash mismatch error")
-	}
-}
-
-func TestChannelValidateInsufficientBits(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	// Mint with 2 bits but require 4.
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	err := validator.ValidateStamp(
-		stamp, 4, testChannel, bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected insufficient bits error")
-	}
-}
-
-func TestChannelValidateZeroBitsSkips(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-
-	err := validator.ValidateStamp(
-		"garbage", 0, "#ch", "abc",
-	)
-	if err != nil {
-		t.Fatalf("zero bits should skip: %v", err)
-	}
-}
-
-func TestChannelValidateBadFormat(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-
-	err := validator.ValidateStamp(
-		"not:valid", testBits, testChannel, "abc",
-	)
-	if err == nil {
-		t.Fatal("expected bad format error")
-	}
-}
-
-func TestChannelValidateBadVersion(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	stamp := "2:2:260317:#general:" + bodyHash + ":counter"
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected bad version error")
-	}
-}
-
-func TestChannelValidateExpiredStamp(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	// Mint with a very old date by manually constructing.
-	stamp := mintStampWithDate(
-		t, testBits, testChannel, "200101",
-	)
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected expired stamp error")
-	}
-}
-
-func TestChannelValidateMissingBodyHash(t *testing.T) {
-	t.Parallel()
-
-	validator := hashcash.NewChannelValidator()
-	bodyHash := testBodyHash()
-
-	// Construct a stamp with empty body hash field.
-	stamp := mintStampWithDate(
-		t, testBits, testChannel, todayDate(),
-	)
-
-	// This uses the session-style stamp which has empty
-	// ext field — body hash is missing.
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err == nil {
-		t.Fatal("expected missing body hash error")
-	}
-}
-
-func TestBodyHash(t *testing.T) {
-	t.Parallel()
-
-	body := []byte(`["hello world"]`)
-	bodyHash := hashcash.BodyHash(body)
-
-	if len(bodyHash) != 64 {
-		t.Fatalf(
-			"expected 64-char hex hash, got %d",
-			len(bodyHash),
-		)
-	}
-
-	// Same input should produce same hash.
-	bodyHash2 := hashcash.BodyHash(body)
-	if bodyHash != bodyHash2 {
-		t.Fatal("body hash not deterministic")
-	}
-
-	// Different input should produce different hash.
-	bodyHash3 := hashcash.BodyHash([]byte("different"))
-	if bodyHash == bodyHash3 {
-		t.Fatal("different inputs produced same hash")
-	}
-}
-
-func TestStampHash(t *testing.T) {
-	t.Parallel()
-
-	hash1 := hashcash.StampHash("stamp1")
-	hash2 := hashcash.StampHash("stamp2")
-
-	if hash1 == hash2 {
-		t.Fatal("different stamps produced same hash")
-	}
-
-	// Same input should be deterministic.
-	hash1b := hashcash.StampHash("stamp1")
-	if hash1 != hash1b {
-		t.Fatal("stamp hash not deterministic")
-	}
-}
-
-func TestMintChannelStamp(t *testing.T) {
-	t.Parallel()
-
-	bodyHash := testBodyHash()
-	stamp := hashcash.MintChannelStamp(
-		testBits, testChannel, bodyHash,
-	)
-
-	if stamp == "" {
-		t.Fatal("expected non-empty stamp")
-	}
-
-	// Validate the minted stamp.
-	validator := hashcash.NewChannelValidator()
-
-	err := validator.ValidateStamp(
-		stamp, testBits, testChannel, bodyHash,
-	)
-	if err != nil {
-		t.Fatalf("minted stamp failed validation: %v", err)
-	}
-}

internal/middleware/middleware.go

@@ -126,23 +126,18 @@ func (mware *Middleware) Logging() func(http.Handler) http.Handler {
 }
 
 // CORS returns middleware that handles Cross-Origin Resource Sharing.
-// AllowCredentials is true so browsers include cookies in
-// cross-origin API requests.
 func (mware *Middleware) CORS() func(http.Handler) http.Handler {
 	return cors.Handler(cors.Options{ //nolint:exhaustruct // optional fields
-		AllowOriginFunc: func(
+		AllowedOrigins: []string{"*"},
-			_ *http.Request, _ string,
-		) bool {
-			return true
-		},
 		AllowedMethods: []string{
 			"GET", "POST", "PUT", "DELETE", "OPTIONS",
 		},
 		AllowedHeaders: []string{
-			"Accept", "Content-Type", "X-CSRF-Token",
+			"Accept", "Authorization",
+			"Content-Type", "X-CSRF-Token",
 		},
 		ExposedHeaders:   []string{"Link"},
-		AllowCredentials: true,
+		AllowCredentials: false,
 		MaxAge:           corsMaxAge,
 	})
 }

internal/ratelimit/ratelimit.go

@@ -0,0 +1,122 @@
+// Package ratelimit provides per-IP rate limiting for HTTP endpoints.
+package ratelimit
+
+import (
+	"sync"
+	"time"
+
+	"golang.org/x/time/rate"
+)
+
+const (
+	// DefaultRate is the default number of allowed requests per second.
+	DefaultRate = 1.0
+
+	// DefaultBurst is the default maximum burst size.
+	DefaultBurst = 5
+
+	// DefaultSweepInterval controls how often stale entries are pruned.
+	DefaultSweepInterval = 10 * time.Minute
+
+	// DefaultEntryTTL is how long an unused entry lives before eviction.
+	DefaultEntryTTL = 15 * time.Minute
+)
+
+// entry tracks a per-IP rate limiter and when it was last used.
+type entry struct {
+	limiter  *rate.Limiter
+	lastSeen time.Time
+}
+
+// Limiter manages per-key rate limiters with automatic cleanup
+// of stale entries.
+type Limiter struct {
+	mu       sync.Mutex
+	entries  map[string]*entry
+	rate     rate.Limit
+	burst    int
+	entryTTL time.Duration
+	stopCh   chan struct{}
+}
+
+// New creates a new per-key rate Limiter.
+// The ratePerSec parameter sets how many requests per second are
+// allowed per key.  The burst parameter sets the maximum number of
+// requests that can be made in a single burst.
+func New(ratePerSec float64, burst int) *Limiter {
+	limiter := &Limiter{
+		mu:       sync.Mutex{},
+		entries:  make(map[string]*entry),
+		rate:     rate.Limit(ratePerSec),
+		burst:    burst,
+		entryTTL: DefaultEntryTTL,
+		stopCh:   make(chan struct{}),
+	}
+
+	go limiter.sweepLoop()
+
+	return limiter
+}
+
+// Allow reports whether a request from the given key should be
+// allowed.  It consumes one token from the key's rate limiter.
+func (l *Limiter) Allow(key string) bool {
+	l.mu.Lock()
+	ent, exists := l.entries[key]
+
+	if !exists {
+		ent = &entry{
+			limiter:  rate.NewLimiter(l.rate, l.burst),
+			lastSeen: time.Now(),
+		}
+		l.entries[key] = ent
+	} else {
+		ent.lastSeen = time.Now()
+	}
+	l.mu.Unlock()
+
+	return ent.limiter.Allow()
+}
+
+// Stop terminates the background sweep goroutine.
+func (l *Limiter) Stop() {
+	close(l.stopCh)
+}
+
+// Len returns the number of tracked keys (for testing).
+func (l *Limiter) Len() int {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	return len(l.entries)
+}
+
+// sweepLoop periodically removes entries that haven't been seen
+// within the TTL.
+func (l *Limiter) sweepLoop() {
+	ticker := time.NewTicker(DefaultSweepInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			l.sweep()
+		case <-l.stopCh:
+			return
+		}
+	}
+}
+
+// sweep removes stale entries.
+func (l *Limiter) sweep() {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	cutoff := time.Now().Add(-l.entryTTL)
+
+	for key, ent := range l.entries {
+		if ent.lastSeen.Before(cutoff) {
+			delete(l.entries, key)
+		}
+	}
+}

internal/ratelimit/ratelimit_test.go

@@ -0,0 +1,106 @@
+package ratelimit_test
+
+import (
+	"testing"
+
+	"git.eeqj.de/sneak/neoirc/internal/ratelimit"
+)
+
+func TestNewCreatesLimiter(t *testing.T) {
+	t.Parallel()
+
+	limiter := ratelimit.New(1.0, 5)
+	defer limiter.Stop()
+
+	if limiter == nil {
+		t.Fatal("expected non-nil limiter")
+	}
+}
+
+func TestAllowWithinBurst(t *testing.T) {
+	t.Parallel()
+
+	limiter := ratelimit.New(1.0, 3)
+	defer limiter.Stop()
+
+	for i := range 3 {
+		if !limiter.Allow("192.168.1.1") {
+			t.Fatalf(
+				"request %d should be allowed within burst",
+				i+1,
+			)
+		}
+	}
+}
+
+func TestAllowExceedsBurst(t *testing.T) {
+	t.Parallel()
+
+	// Rate of 0 means no token replenishment, only burst.
+	limiter := ratelimit.New(0, 3)
+	defer limiter.Stop()
+
+	for range 3 {
+		limiter.Allow("10.0.0.1")
+	}
+
+	if limiter.Allow("10.0.0.1") {
+		t.Fatal("fourth request should be denied after burst exhausted")
+	}
+}
+
+func TestAllowSeparateKeys(t *testing.T) {
+	t.Parallel()
+
+	// Rate of 0, burst of 1 — only one request per key.
+	limiter := ratelimit.New(0, 1)
+	defer limiter.Stop()
+
+	if !limiter.Allow("10.0.0.1") {
+		t.Fatal("first request for key A should be allowed")
+	}
+
+	if !limiter.Allow("10.0.0.2") {
+		t.Fatal("first request for key B should be allowed")
+	}
+
+	if limiter.Allow("10.0.0.1") {
+		t.Fatal("second request for key A should be denied")
+	}
+
+	if limiter.Allow("10.0.0.2") {
+		t.Fatal("second request for key B should be denied")
+	}
+}
+
+func TestLenTracksKeys(t *testing.T) {
+	t.Parallel()
+
+	limiter := ratelimit.New(1.0, 5)
+	defer limiter.Stop()
+
+	if limiter.Len() != 0 {
+		t.Fatalf("expected 0 entries, got %d", limiter.Len())
+	}
+
+	limiter.Allow("10.0.0.1")
+	limiter.Allow("10.0.0.2")
+
+	if limiter.Len() != 2 {
+		t.Fatalf("expected 2 entries, got %d", limiter.Len())
+	}
+
+	// Same key again should not increase count.
+	limiter.Allow("10.0.0.1")
+
+	if limiter.Len() != 2 {
+		t.Fatalf("expected 2 entries, got %d", limiter.Len())
+	}
+}
+
+func TestStopDoesNotPanic(t *testing.T) {
+	t.Parallel()
+
+	limiter := ratelimit.New(1.0, 5)
+	limiter.Stop()
+}

internal/server/routes.go

@@ -75,6 +75,10 @@ func (srv *Server) setupAPIv1(router chi.Router) {
 		"/session",
 		srv.handlers.HandleCreateSession(),
 	)
+	router.Post(
+		"/register",
+		srv.handlers.HandleRegister(),
+	)
 	router.Post(
 		"/login",
 		srv.handlers.HandleLogin(),

pkg/irc/commands.go

@@ -11,7 +11,6 @@ const (
 	CmdNames   = "NAMES"
 	CmdNick    = "NICK"
 	CmdNotice  = "NOTICE"
-	CmdPass    = "PASS"
 	CmdPart    = "PART"
 	CmdPing    = "PING"
 	CmdPong    = "PONG"