Initial commit: TravelHub multi-tenant flight booking platform

Angular + Go + PostgreSQL sample with strict per-tenant isolation. - Backend: Go API (basic auth, tenant-scoped repository layer, pgx pool) - Frontend: Angular 22 SPA (search, checkout, bookings, dashboard) - Database: schema, seed data and demo bookings migrations - Tests: 311 across Go (integration), Angular (unit) and Playwright (e2e), plus a generated evidence report with PDF export - Security: whitebox VAPT report under security/ Secrets (.env, tokens, DB credentials) are git-ignored. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-09-13 11:38:01 +05:30
commit 4d3eb18a6c
129 changed files with 25424 additions and 0 deletions
@@ -0,0 +1,223 @@
+// Package middleware contains the HTTP layer that runs before handlers:
+// panic recovery, logging, CORS, and Basic authentication with tenant
+// resolution.
+package middleware
+
+import (
+	"crypto/subtle"
+	"encoding/json"
+	"errors"
+	"log/slog"
+	"net/http"
+	"strings"
+	"time"
+
+	"golang.org/x/crypto/bcrypt"
+
+	"github.com/travelswitch/travelhub/backend/internal/auth"
+	"github.com/travelswitch/travelhub/backend/internal/repository"
+)
+
+// TenantHeader names the header an SPA uses to say which agency it is signing
+// in to. A subdomain is used as a fallback so the same build works when
+// deployed as skyline.example.com.
+const TenantHeader = "X-Tenant"
+
+// Recoverer turns a panic into a 500 instead of killing the connection.
+func Recoverer(logger *slog.Logger) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			defer func() {
+				if rec := recover(); rec != nil {
+					logger.Error("panic serving request",
+						"method", r.Method, "path", r.URL.Path, "panic", rec)
+					writeError(w, http.StatusInternalServerError, "internal server error")
+				}
+			}()
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// statusRecorder remembers the status code so the logger can report it.
+type statusRecorder struct {
+	http.ResponseWriter
+	status int
+}
+
+func (s *statusRecorder) WriteHeader(code int) {
+	s.status = code
+	s.ResponseWriter.WriteHeader(code)
+}
+
+// Logger writes one line per request.
+func Logger(logger *slog.Logger) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			start := time.Now()
+			rec := &statusRecorder{ResponseWriter: w, status: http.StatusOK}
+			next.ServeHTTP(rec, r)
+			logger.Info("request",
+				"method", r.Method,
+				"path", r.URL.Path,
+				"status", rec.status,
+				"tenant", r.Header.Get(TenantHeader),
+				"duration", time.Since(start).String(),
+			)
+		})
+	}
+}
+
+// CORS answers preflights and echoes back only origins on the allow list.
+func CORS(allowed []string) func(http.Handler) http.Handler {
+	allowSet := make(map[string]bool, len(allowed))
+	for _, o := range allowed {
+		allowSet[strings.TrimSuffix(o, "/")] = true
+	}
+
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			origin := strings.TrimSuffix(r.Header.Get("Origin"), "/")
+			if origin != "" && allowSet[origin] {
+				h := w.Header()
+				h.Set("Access-Control-Allow-Origin", origin)
+				h.Set("Access-Control-Allow-Credentials", "true")
+				h.Set("Access-Control-Allow-Headers", "Authorization, Content-Type, "+TenantHeader)
+				h.Set("Access-Control-Allow-Methods", "GET, POST, PATCH, DELETE, OPTIONS")
+				h.Set("Access-Control-Max-Age", "600")
+				// Responses differ per origin, so caches must key on it.
+				h.Add("Vary", "Origin")
+			}
+
+			if r.Method == http.MethodOptions {
+				w.WriteHeader(http.StatusNoContent)
+				return
+			}
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// BasicAuth authenticates the caller and pins them to one tenant.
+//
+// Both halves matter: the password is checked against the user row *inside*
+// the named tenant, so identical credentials at another agency will not
+// authenticate here. The resolved tenant goes into the request context and is
+// the only tenant id the handlers below ever use.
+func BasicAuth(repo *repository.Repository, logger *slog.Logger) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			slug := tenantSlug(r)
+			if slug == "" {
+				writeError(w, http.StatusBadRequest,
+					"missing tenant: send the "+TenantHeader+" header")
+				return
+			}
+
+			email, password, ok := r.BasicAuth()
+			if !ok {
+				unauthorized(w)
+				return
+			}
+
+			ctx := r.Context()
+			tenant, err := repo.TenantBySlug(ctx, slug)
+			if err != nil {
+				if errors.Is(err, repository.ErrNotFound) {
+					// Same response as a bad password: do not let an
+					// unauthenticated caller enumerate which tenants exist.
+					unauthorized(w)
+					return
+				}
+				logger.Error("tenant lookup failed", "error", err)
+				writeError(w, http.StatusInternalServerError, "internal server error")
+				return
+			}
+
+			user, err := repo.UserByEmail(ctx, tenant.ID, email)
+			if err != nil {
+				if errors.Is(err, repository.ErrNotFound) {
+					// Hash a throwaway value so a missing user costs the same
+					// time as a wrong password, which stops an attacker
+					// learning valid addresses from response timing.
+					bcrypt.CompareHashAndPassword(dummyHash, []byte(password))
+					unauthorized(w)
+					return
+				}
+				logger.Error("user lookup failed", "error", err)
+				writeError(w, http.StatusInternalServerError, "internal server error")
+				return
+			}
+
+			if bcrypt.CompareHashAndPassword([]byte(user.PasswordHash), []byte(password)) != nil {
+				unauthorized(w)
+				return
+			}
+
+			// Defence in depth: the user row must belong to the tenant we
+			// resolved. The query already guarantees it; this catches a future
+			// refactor that breaks the invariant.
+			if subtle.ConstantTimeCompare(user.TenantID[:], tenant.ID[:]) != 1 {
+				unauthorized(w)
+				return
+			}
+
+			ctx = auth.WithIdentity(ctx, auth.Identity{User: user, Tenant: tenant})
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+}
+
+// RequireAdmin gates routes that only a tenant administrator may call.
+func RequireAdmin(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		id, err := auth.FromContext(r.Context())
+		if err != nil || !id.IsAdmin() {
+			writeError(w, http.StatusForbidden, "administrator role required")
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
+// dummyHash is a valid bcrypt hash of a value nobody uses, for timing parity.
+var dummyHash = []byte("$2a$10$N9qo8uLOickgx2ZMRZoMyeIjZAgcfl7p92ldGxad68LJZdL17lhWy")
+
+// tenantSlug reads the tenant from the header, falling back to the first label
+// of the Host name for subdomain-per-tenant deployments.
+func tenantSlug(r *http.Request) string {
+	if v := strings.TrimSpace(r.Header.Get(TenantHeader)); v != "" {
+		return strings.ToLower(v)
+	}
+
+	host := r.Host
+	if h, _, found := strings.Cut(host, ":"); found {
+		host = h
+	}
+	labels := strings.Split(host, ".")
+	if len(labels) >= 3 && labels[0] != "www" {
+		return strings.ToLower(labels[0])
+	}
+	return ""
+}
+
+// unauthorized replies 401 without a WWW-Authenticate header on purpose: that
+// header makes browsers open their own credential dialog, which would fight
+// with the Angular sign-in screen.
+func unauthorized(w http.ResponseWriter) {
+	writeError(w, http.StatusUnauthorized, "invalid credentials for this tenant")
+}
+
+func writeError(w http.ResponseWriter, status int, message string) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	json.NewEncoder(w).Encode(map[string]string{"error": message})
+}
+
+// Chain applies middleware so the first argument is the outermost layer.
+func Chain(h http.Handler, mw ...func(http.Handler) http.Handler) http.Handler {
+	for i := len(mw) - 1; i >= 0; i-- {
+		h = mw[i](h)
+	}
+	return h
+}