Block credential/exploit scanner paths at middleware

internal/engine/engine.go

@@ -1229,9 +1229,15 @@ Docs:      https://stockyard.dev/docs
 	// Gzip compression (outermost — compresses all HTML, JSON, text responses)
 	srv.WrapHandler(gzipMiddleware)
 
-	// Panic recovery (outermost — catches panics from any handler, returns clean 500)
+	// Panic recovery (catches panics from any handler, returns clean 500)
 	srv.WrapHandler(recoveryMiddleware)
 
+	// Scanner block (outermost — runs first on every request).
+	// Short-circuits known credential/exploit scanner paths (.env, phpinfo,
+	// wp-admin, etc.) with a 403 before any handler, template, or DB work.
+	// See internal/engine/scanner_block.go for pattern list and rationale.
+	srv.WrapHandler(scannerBlockMiddleware)
+
 	// Register marketing website (/, /docs/, /pricing/, etc.)
 	site.Register(srv.Mux(), db.Conn())
 

internal/engine/scanner_block.go

@@ -0,0 +1,40 @@
+package engine
+
+import (
+	"net/http"
+	"strings"
+)
+
+// scannerBlockPatterns are URL path substrings that only credential/exploit
+// scanners ever request. The marketing site has no real route that matches
+// any of these, so blocking is safe and stops bots from probing for leaked
+// .env files, phpinfo dumps, WordPress installs, etc.
+//
+// Observed in the wild against stockyard.dev (Cloudflare analytics, 2026-04):
+// ~60 unique scanner paths/day driving ~75% of all 404s. None hit real routes.
+var scannerBlockPatterns = []string{
+	".env",        // catches /.env, /.env.bak, /.env.production, /backend/.env, etc.
+	"phpinfo",     // catches /phpinfo.php, /old_phpinfo.php, /hosting/phpinfo.php, etc.
+	"wp-admin",    // catches /wp-admin/install.php and any wp-admin probe
+	"wp-login",    // catches /wp-login.php
+	"/debug.php",  // exact-match scanner path
+	"/php.php",    // exact-match scanner path
+}
+
+// scannerBlockMiddleware short-circuits requests for known credential/exploit
+// scanner paths with a 403, before any handler, template, or DB work runs.
+//
+// Wrap this OUTERMOST (last WrapHandler call) so it runs first on every
+// request. Cost per blocked request: a handful of strings.Contains calls.
+func scannerBlockMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		path := r.URL.Path
+		for _, pat := range scannerBlockPatterns {
+			if strings.Contains(path, pat) {
+				http.Error(w, "Forbidden", http.StatusForbidden)
+				return
+			}
+		}
+		next.ServeHTTP(w, r)
+	})
+}

internal/engine/scanner_block_test.go

@@ -0,0 +1,67 @@
+package engine
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestScannerBlockMiddleware(t *testing.T) {
+	// Inner handler always returns 200 — middleware should short-circuit
+	// before this runs for blocked paths.
+	inner := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("ok"))
+	})
+	h := scannerBlockMiddleware(inner)
+
+	tests := []struct {
+		name     string
+		path     string
+		wantCode int
+	}{
+		// Should be blocked (real scanner paths observed in production)
+		{"dotenv root", "/.env", http.StatusForbidden},
+		{"dotenv backup", "/.env.bak", http.StatusForbidden},
+		{"dotenv production", "/.env.production", http.StatusForbidden},
+		{"dotenv test", "/.env.test", http.StatusForbidden},
+		{"dotenv nested backend", "/backend/.env", http.StatusForbidden},
+		{"dotenv nested storage", "/storage/.env", http.StatusForbidden},
+		{"phpinfo plain", "/phpinfo.php", http.StatusForbidden},
+		{"phpinfo old", "/old_phpinfo.php", http.StatusForbidden},
+		{"phpinfo nested", "/hosting/phpinfo.php", http.StatusForbidden},
+		{"wp-admin install", "/wp-admin/install.php", http.StatusForbidden},
+		{"wp-login", "/wp-login.php", http.StatusForbidden},
+		{"debug.php", "/debug.php", http.StatusForbidden},
+		{"php.php", "/php.php", http.StatusForbidden},
+
+		// Should pass through (real site paths must NEVER be blocked)
+		{"homepage", "/", http.StatusOK},
+		{"pricing", "/pricing/", http.StatusOK},
+		{"desktop", "/desktop/", http.StatusOK},
+		{"installer macos", "/api/installer/macos", http.StatusOK},
+		{"installer linux", "/api/installer/linux", http.StatusOK},
+		{"installer windows", "/api/installer/windows", http.StatusOK},
+		{"recommend", "/api/recommend", http.StatusOK},
+		{"toolkit count", "/api/toolkit-count", http.StatusOK},
+		{"robots", "/robots.txt", http.StatusOK},
+		{"sitemap", "/sitemap.xml", http.StatusOK},
+		{"favicon", "/favicon.ico", http.StatusOK},
+		{"site asset svg", "/site-assets/assets/screenshots/tool-assay.svg", http.StatusOK},
+		{"for solo developers", "/for/solo-developers/", http.StatusOK},
+		{"tools listing", "/tools/", http.StatusOK},
+		{"playground", "/playground", http.StatusOK},
+		{"v1 chat completions", "/v1/chat/completions", http.StatusOK},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req := httptest.NewRequest(http.MethodGet, tt.path, nil)
+			w := httptest.NewRecorder()
+			h.ServeHTTP(w, req)
+			if w.Code != tt.wantCode {
+				t.Errorf("path %s: got status %d, want %d", tt.path, w.Code, tt.wantCode)
+			}
+		})
+	}
+}