feat(auth): implement strict and secure user registration

internal/features/auth/auth.go

@@ -8,7 +8,9 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"os"
 	"time"
+	"unicode"
 
 	"github.com/google/uuid"
 	"golang.org/x/crypto/bcrypt"
@@ -20,6 +22,7 @@ var (
 	ErrInvalidCredentials = errors.New("invalid username or password")
 	ErrUserExists         = errors.New("username already exists")
 	ErrNotAuthenticated   = errors.New("not authenticated")
+	ErrInvalidPassword    = errors.New("password does not meet security requirements")
 )
 
 type Service struct {
@@ -39,8 +42,37 @@ func generateSessionToken() (string, error) {
 	return base64.URLEncoding.EncodeToString(b), nil
 }
 
+func ValidatePassword(password string) error {
+	if len(password) < 12 {
+		return fmt.Errorf("password must be at least 12 characters long")
+	}
+
+	var hasUpper, hasLower, hasNumber, hasSpecial bool
+	for _, c := range password {
+		switch {
+		case unicode.IsNumber(c):
+			hasNumber = true
+		case unicode.IsUpper(c):
+			hasUpper = true
+		case unicode.IsLower(c):
+			hasLower = true
+		case unicode.IsPunct(c) || unicode.IsSymbol(c) || !unicode.IsLetter(c) && !unicode.IsNumber(c):
+			hasSpecial = true
+		}
+	}
+
+	if !hasUpper || !hasLower || !hasNumber || !hasSpecial {
+		return fmt.Errorf("password must contain at least one uppercase letter, one lowercase letter, one number, and one special character")
+	}
+	return nil
+}
+
 func (s *Service) RegisterUser(ctx context.Context, username, password string) (*database.User, error) {
-	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err := ValidatePassword(password); err != nil {
+		return nil, fmt.Errorf("%w: %v", ErrInvalidPassword, err)
+	}
+
+	hash, err := bcrypt.GenerateFromPassword([]byte(password), 12) // higher cost
 	if err != nil {
 		return nil, fmt.Errorf("failed to hash password: %w", err)
 	}
@@ -117,25 +149,27 @@ func (s *Service) ValidateSession(ctx context.Context, sessionID string) (*datab
 }
 
 func SetSessionCookie(w http.ResponseWriter, sessionID string, expiresAt time.Time) {
+	isProd := os.Getenv("ENV") == "production"
 	http.SetCookie(w, &http.Cookie{
 		Name:     "session_id",
 		Value:    sessionID,
 		Expires:  expiresAt,
 		HttpOnly: true,
-		Secure:   false, // False for local development without TLS
+		Secure:   isProd,
-		SameSite: http.SameSiteLaxMode,
+		SameSite: http.SameSiteStrictMode,
 		Path:     "/",
 	})
 }
 
 func ClearSessionCookie(w http.ResponseWriter) {
+	isProd := os.Getenv("ENV") == "production"
 	http.SetCookie(w, &http.Cookie{
 		Name:     "session_id",
 		Value:    "",
 		Expires:  time.Unix(0, 0),
 		HttpOnly: true,
-		Secure:   false, // False for local development without TLS
+		Secure:   isProd,
-		SameSite: http.SameSiteLaxMode,
+		SameSite: http.SameSiteStrictMode,
 		Path:     "/",
 	})
 }

internal/features/auth/handler.go

@@ -39,6 +39,47 @@ func (h *Handler) HandleLogin(w http.ResponseWriter, r *http.Request) {
 	http.Redirect(w, r, "/", http.StatusFound)
 }
 
+func (h *Handler) HandleRegister(w http.ResponseWriter, r *http.Request) {
+	if err := r.ParseForm(); err != nil {
+		http.Error(w, "invalid request", http.StatusBadRequest)
+		return
+	}
+
+	username := r.FormValue("username")
+	password := r.FormValue("password")
+
+	if username == "" || password == "" {
+		http.Error(w, "username and password are required", http.StatusBadRequest)
+		return
+	}
+
+	_, err := h.authService.RegisterUser(r.Context(), username, password)
+	if err != nil {
+		if err == ErrInvalidPassword {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		if err == ErrUserExists {
+			http.Error(w, "username already taken", http.StatusConflict)
+			return
+		}
+		http.Error(w, "registration failed", http.StatusInternalServerError)
+		return
+	}
+
+	// Auto-login after successful registration
+	session, err := h.authService.Login(r.Context(), username, password)
+	if err != nil {
+		http.Redirect(w, r, "/login", http.StatusFound)
+		return
+	}
+
+	SetSessionCookie(w, session.ID, session.ExpiresAt)
+
+	w.Header().Set("HX-Redirect", "/")
+	http.Redirect(w, r, "/", http.StatusFound)
+}
+
 func (h *Handler) HandleLogout(w http.ResponseWriter, r *http.Request) {
 	cookie, err := r.Cookie("session_id")
 	if err == nil {
@@ -53,3 +94,7 @@ func (h *Handler) HandleLogout(w http.ResponseWriter, r *http.Request) {
 func (h *Handler) HandleLoginPage(w http.ResponseWriter, r *http.Request) {
 	templates.Login().Render(r.Context(), w)
 }
+
+func (h *Handler) HandleRegisterPage(w http.ResponseWriter, r *http.Request) {
+	templates.Register().Render(r.Context(), w)
+}

internal/server/routes.go

@@ -53,10 +53,19 @@ func NewRouter(cfg Config) http.Handler {
 		if r.Method == http.MethodGet {
 			authHandler.HandleLoginPage(w, r)
 		} else {
-			authHandler.HandleLogin(w, r)
+			middleware.RateLimitAuth(middleware.VerifyOrigin(http.HandlerFunc(authHandler.HandleLogin))).ServeHTTP(w, r)
 		}
 	})
-	mux.HandleFunc("/logout", authHandler.HandleLogout)
+	mux.HandleFunc("/register", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodGet {
+			authHandler.HandleRegisterPage(w, r)
+		} else {
+			middleware.RateLimitAuth(middleware.VerifyOrigin(http.HandlerFunc(authHandler.HandleRegister))).ServeHTTP(w, r)
+		}
+	})
+	mux.HandleFunc("/logout", func(w http.ResponseWriter, r *http.Request) {
+		middleware.VerifyOrigin(http.HandlerFunc(authHandler.HandleLogout)).ServeHTTP(w, r)
+	})
 
 	// Watchlist POST endpoint (Protected)
 	mux.Handle("/api/watchlist/export", middleware.RequireAuth(http.HandlerFunc(watchlistHandler.HandleExportWatchlist)))

internal/shared/middleware/auth.go

@@ -61,8 +61,8 @@ func RequireAuth(next http.Handler) http.Handler {
 // RequireGlobalAuth ensures that a valid user is in the context for all routes except login and static
 func RequireGlobalAuth(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		// Allow unauthenticated access to login, search, and static files
+		// Allow unauthenticated access to login, register, search, and static files
-		if r.URL.Path == "/login" || strings.HasPrefix(r.URL.Path, "/static/") ||
+		if r.URL.Path == "/login" || r.URL.Path == "/register" || strings.HasPrefix(r.URL.Path, "/static/") ||
 			r.URL.Path == "/search" || r.URL.Path == "/api/search" || r.URL.Path == "/api/search-quick" ||
 			r.URL.Path == "/" {
 			next.ServeHTTP(w, r)

internal/shared/middleware/csrf.go

@@ -0,0 +1,48 @@
+package middleware
+
+import (
+	"net/http"
+	"net/url"
+)
+
+// VerifyOrigin prevents simple CSRF by ensuring the Origin or Referer header matches the Host header
+// for state-changing endpoints (POST/PUT/DELETE).
+func VerifyOrigin(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodGet || r.Method == http.MethodHead || r.Method == http.MethodOptions {
+			next.ServeHTTP(w, r)
+			return
+		}
+
+		origin := r.Header.Get("Origin")
+		if origin == "" {
+			referer := r.Header.Get("Referer")
+			if referer == "" {
+				// If neither is present, and it's a POST/PUT/DELETE, reject it (strict policy)
+				http.Error(w, "Missing Origin or Referer header", http.StatusForbidden)
+				return
+			}
+			
+			refURL, err := url.Parse(referer)
+			if err != nil {
+				http.Error(w, "Invalid Referer header", http.StatusForbidden)
+				return
+			}
+			origin = refURL.Scheme + "://" + refURL.Host
+		}
+
+		host := r.Host
+		// Optional: strip port if you only care about domain
+		
+		// If origin doesn't match host (accounting for potential schema prefixes)
+		expectedHTTP := "http://" + host
+		expectedHTTPS := "https://" + host
+		
+		if origin != expectedHTTP && origin != expectedHTTPS {
+			http.Error(w, "Cross-Site Request Forgery (CSRF) origin mismatch", http.StatusForbidden)
+			return
+		}
+
+		next.ServeHTTP(w, r)
+	})
+}

internal/shared/middleware/ratelimit.go

@@ -0,0 +1,81 @@
+package middleware
+
+import (
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+)
+
+type visitor struct {
+	attempts int
+	lastSeen time.Time
+}
+
+var (
+	visitors = make(map[string]*visitor)
+	mu       sync.Mutex
+)
+
+func init() {
+	go cleanupVisitors()
+}
+
+func cleanupVisitors() {
+	for {
+		time.Sleep(time.Minute)
+		mu.Lock()
+		for ip, v := range visitors {
+			if time.Since(v.lastSeen) > 3*time.Minute {
+				delete(visitors, ip)
+			}
+		}
+		mu.Unlock()
+	}
+}
+
+// getIP attempts to get the real IP, falling back to RemoteAddr
+func getIP(r *http.Request) string {
+	if xff := r.Header.Get("X-Forwarded-For"); xff != "" {
+		ips := strings.Split(xff, ",")
+		return strings.TrimSpace(ips[0])
+	}
+	if realIP := r.Header.Get("X-Real-IP"); realIP != "" {
+		return realIP
+	}
+	ip := r.RemoteAddr
+	if colonIdx := strings.LastIndex(ip, ":"); colonIdx != -1 {
+		ip = ip[:colonIdx]
+	}
+	return ip
+}
+
+// RateLimitAuth limits login/register attempts to prevent brute force
+func RateLimitAuth(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		ip := getIP(r)
+
+		mu.Lock()
+		v, exists := visitors[ip]
+		if !exists {
+			visitors[ip] = &visitor{1, time.Now()}
+		} else {
+			// Reset attempts if it's been more than a minute
+			if time.Since(v.lastSeen) > time.Minute {
+				v.attempts = 0
+			}
+			v.attempts++
+			v.lastSeen = time.Now()
+		}
+		
+		// If more than 5 attempts within a minute, block
+		if exists && v.attempts > 5 {
+			mu.Unlock()
+			http.Error(w, "Too many requests. Please try again later.", http.StatusTooManyRequests)
+			return
+		}
+		mu.Unlock()
+
+		next.ServeHTTP(w, r)
+	})
+}

internal/templates/auth.templ

@@ -7,7 +7,7 @@ templ Login() {
 			<p class="login-subtitle">enter your credentials to continue</p>
 			<form action="/login" method="POST" class="login-form">
 				<div class="form-group">
-					<label for="username">email</label>
+					<label for="username">username / email</label>
 					<input type="text" id="username" name="username" required placeholder="you@example.com"/>
 				</div>
 				<div class="form-group">
@@ -16,6 +16,35 @@ templ Login() {
 				</div>
 				<button type="submit" class="login-button">sign in</button>
 			</form>
+			<p style="margin-top: 1rem; text-align: center; color: var(--text-muted); font-size: var(--text-sm);">
+				don't have an account? <a href="/register" style="color: var(--primary);">register</a>
+			</p>
+		</div>
+	}
+}
+
+templ Register() {
+	@Layout("Register") {
+		<div class="login-container">
+			<h2>register</h2>
+			<p class="login-subtitle">create a new account to track anime</p>
+			<form action="/register" method="POST" class="login-form">
+				<div class="form-group">
+					<label for="username">username / email</label>
+					<input type="text" id="username" name="username" required placeholder="you@example.com"/>
+				</div>
+				<div class="form-group">
+					<label for="password">password</label>
+					<input type="password" id="password" name="password" required placeholder="minimum 12 chars"/>
+				</div>
+				<p style="font-size: 0.75rem; color: var(--text-muted); margin-bottom: 1rem; line-height: 1.4;">
+					Password must be at least 12 characters and include an uppercase letter, lowercase letter, number, and special character.
+				</p>
+				<button type="submit" class="login-button">create account</button>
+			</form>
+			<p style="margin-top: 1rem; text-align: center; color: var(--text-muted); font-size: var(--text-sm);">
+				already have an account? <a href="/login" style="color: var(--primary);">sign in</a>
+			</p>
 		</div>
 	}
 }

internal/templates/auth_templ.go

@@ -41,7 +41,7 @@ func Login() templ.Component {
 				}()
 			}
 			ctx = templ.InitializeContext(ctx)
-			templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 1, "<div class=\"login-container\"><h2>sign in</h2><p class=\"login-subtitle\">enter your credentials to continue</p><form action=\"/login\" method=\"POST\" class=\"login-form\"><div class=\"form-group\"><label for=\"username\">email</label> <input type=\"text\" id=\"username\" name=\"username\" required placeholder=\"you@example.com\"></div><div class=\"form-group\"><label for=\"password\">password</label> <input type=\"password\" id=\"password\" name=\"password\" required placeholder=\"your password\"></div><button type=\"submit\" class=\"login-button\">sign in</button></form></div>")
+			templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 1, "<div class=\"login-container\"><h2>sign in</h2><p class=\"login-subtitle\">enter your credentials to continue</p><form action=\"/login\" method=\"POST\" class=\"login-form\"><div class=\"form-group\"><label for=\"username\">username / email</label> <input type=\"text\" id=\"username\" name=\"username\" required placeholder=\"you@example.com\"></div><div class=\"form-group\"><label for=\"password\">password</label> <input type=\"password\" id=\"password\" name=\"password\" required placeholder=\"your password\"></div><button type=\"submit\" class=\"login-button\">sign in</button></form><p style=\"margin-top: 1rem; text-align: center; color: var(--text-muted); font-size: var(--text-sm);\">don't have an account? <a href=\"/register\" style=\"color: var(--primary);\">register</a></p></div>")
 			if templ_7745c5c3_Err != nil {
 				return templ_7745c5c3_Err
 			}
@@ -55,4 +55,51 @@ func Login() templ.Component {
 	})
 }
 
+func Register() templ.Component {
+	return templruntime.GeneratedTemplate(func(templ_7745c5c3_Input templruntime.GeneratedComponentInput) (templ_7745c5c3_Err error) {
+		templ_7745c5c3_W, ctx := templ_7745c5c3_Input.Writer, templ_7745c5c3_Input.Context
+		if templ_7745c5c3_CtxErr := ctx.Err(); templ_7745c5c3_CtxErr != nil {
+			return templ_7745c5c3_CtxErr
+		}
+		templ_7745c5c3_Buffer, templ_7745c5c3_IsBuffer := templruntime.GetBuffer(templ_7745c5c3_W)
+		if !templ_7745c5c3_IsBuffer {
+			defer func() {
+				templ_7745c5c3_BufErr := templruntime.ReleaseBuffer(templ_7745c5c3_Buffer)
+				if templ_7745c5c3_Err == nil {
+					templ_7745c5c3_Err = templ_7745c5c3_BufErr
+				}
+			}()
+		}
+		ctx = templ.InitializeContext(ctx)
+		templ_7745c5c3_Var3 := templ.GetChildren(ctx)
+		if templ_7745c5c3_Var3 == nil {
+			templ_7745c5c3_Var3 = templ.NopComponent
+		}
+		ctx = templ.ClearChildren(ctx)
+		templ_7745c5c3_Var4 := templruntime.GeneratedTemplate(func(templ_7745c5c3_Input templruntime.GeneratedComponentInput) (templ_7745c5c3_Err error) {
+			templ_7745c5c3_W, ctx := templ_7745c5c3_Input.Writer, templ_7745c5c3_Input.Context
+			templ_7745c5c3_Buffer, templ_7745c5c3_IsBuffer := templruntime.GetBuffer(templ_7745c5c3_W)
+			if !templ_7745c5c3_IsBuffer {
+				defer func() {
+					templ_7745c5c3_BufErr := templruntime.ReleaseBuffer(templ_7745c5c3_Buffer)
+					if templ_7745c5c3_Err == nil {
+						templ_7745c5c3_Err = templ_7745c5c3_BufErr
+					}
+				}()
+			}
+			ctx = templ.InitializeContext(ctx)
+			templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 2, "<div class=\"login-container\"><h2>register</h2><p class=\"login-subtitle\">create a new account to track anime</p><form action=\"/register\" method=\"POST\" class=\"login-form\"><div class=\"form-group\"><label for=\"username\">username / email</label> <input type=\"text\" id=\"username\" name=\"username\" required placeholder=\"you@example.com\"></div><div class=\"form-group\"><label for=\"password\">password</label> <input type=\"password\" id=\"password\" name=\"password\" required placeholder=\"minimum 12 chars\"></div><p style=\"font-size: 0.75rem; color: var(--text-muted); margin-bottom: 1rem; line-height: 1.4;\">Password must be at least 12 characters and include an uppercase letter, lowercase letter, number, and special character.</p><button type=\"submit\" class=\"login-button\">create account</button></form><p style=\"margin-top: 1rem; text-align: center; color: var(--text-muted); font-size: var(--text-sm);\">already have an account? <a href=\"/login\" style=\"color: var(--primary);\">sign in</a></p></div>")
+			if templ_7745c5c3_Err != nil {
+				return templ_7745c5c3_Err
+			}
+			return nil
+		})
+		templ_7745c5c3_Err = Layout("Register").Render(templ.WithChildren(ctx, templ_7745c5c3_Var4), templ_7745c5c3_Buffer)
+		if templ_7745c5c3_Err != nil {
+			return templ_7745c5c3_Err
+		}
+		return nil
+	})
+}
+
 var _ = templruntime.GeneratedTemplate