first commit

middlewares/dynamic_cors.go

@@ -0,0 +1,137 @@
+package middlewares
+
+import (
+	"encoding/json"
+	"errors"
+	configs "goFiber/config"
+	database "goFiber/database/config"
+	"goFiber/database/models"
+	"log"
+	"net/http"
+	"strings"
+
+	"github.com/gofiber/fiber/v3"
+	"github.com/redis/go-redis/v9"
+)
+
+const (
+	corsWhitelistActiveCacheKey = "cors:active:whitelist"
+	corsBlacklistActiveCacheKey = "cors:active:blacklist"
+	corsCacheTTLSeconds         = 60
+)
+
+var (
+	allowedMethods = "GET,POST,PUT,PATCH,DELETE,OPTIONS"
+	allowedHeaders = "Authorization,Content-Type,Accept,Origin,X-Requested-With"
+)
+
+// DynamicCORS validates request Origin using DB-backed whitelist/blacklist with Redis caching.
+func DynamicCORS() fiber.Handler {
+	return func(c fiber.Ctx) error {
+		origin := strings.TrimSpace(c.Get("Origin"))
+		if origin == "" {
+			return c.Next()
+		}
+		if database.DB == nil {
+			corsLogf("[cors][skip] database unavailable origin=%s path=%s", origin, c.Path())
+			return c.Next()
+		}
+
+		originKey := strings.ToLower(origin)
+		// Keep same-origin requests working even if DB entries are missing.
+		if origin == requestBaseURL(c) {
+			corsLogf("[cors][allow] same-origin origin=%s path=%s", origin, c.Path())
+			setCORSHeaders(c, origin)
+			if c.Method() == http.MethodOptions {
+				return c.SendStatus(http.StatusNoContent)
+			}
+			return c.Next()
+		}
+
+		blacklist, err := loadActiveOriginSet(corsBlacklistActiveCacheKey, true)
+		if err != nil {
+			return c.Status(http.StatusInternalServerError).JSON(fiber.Map{"error": "cors blacklist lookup failed"})
+		}
+		if blacklist[originKey] {
+			log.Printf("[cors][blocked] blacklist origin=%s path=%s", origin, c.Path())
+			return c.Status(http.StatusForbidden).JSON(fiber.Map{"error": "origin is blocked by CORS policy"})
+		}
+
+		whitelist, err := loadActiveOriginSet(corsWhitelistActiveCacheKey, false)
+		if err != nil {
+			return c.Status(http.StatusInternalServerError).JSON(fiber.Map{"error": "cors whitelist lookup failed"})
+		}
+		if !whitelist[originKey] {
+			log.Printf("[cors][blocked] not-whitelisted origin=%s path=%s", origin, c.Path())
+			return c.Status(http.StatusForbidden).JSON(fiber.Map{"error": "origin is not allowed by CORS policy"})
+		}
+
+		corsLogf("[cors][allow] origin=%s path=%s", origin, c.Path())
+		setCORSHeaders(c, origin)
+		if c.Method() == http.MethodOptions {
+			return c.SendStatus(http.StatusNoContent)
+		}
+		return c.Next()
+	}
+}
+
+func setCORSHeaders(c fiber.Ctx, origin string) {
+	c.Set("Vary", "Origin")
+	c.Set("Access-Control-Allow-Origin", origin)
+	c.Set("Access-Control-Allow-Methods", allowedMethods)
+	c.Set("Access-Control-Allow-Headers", allowedHeaders)
+	c.Set("Access-Control-Allow-Credentials", "true")
+	c.Set("Access-Control-Max-Age", "600")
+}
+
+func requestBaseURL(c fiber.Ctx) string {
+	return c.Protocol() + "://" + c.Get("Host")
+}
+
+func loadActiveOriginSet(cacheKey string, isBlacklist bool) (map[string]bool, error) {
+	out := make(map[string]bool)
+
+	if cached, err := database.Get(cacheKey); err == nil {
+		corsLogf("[cors][cache-hit] key=%s", cacheKey)
+		var origins []string
+		if jsonErr := json.Unmarshal([]byte(cached), &origins); jsonErr == nil {
+			for _, origin := range origins {
+				out[strings.ToLower(strings.TrimSpace(origin))] = true
+			}
+			return out, nil
+		}
+	} else if !errors.Is(err, redis.Nil) {
+		return nil, err
+	}
+	corsLogf("[cors][cache-miss] key=%s", cacheKey)
+
+	var origins []string
+	var dbErr error
+	if isBlacklist {
+		dbErr = database.DB.Model(&models.CorsBlacklist{}).
+			Where("is_active = ?", true).
+			Pluck("origin", &origins).Error
+	} else {
+		dbErr = database.DB.Model(&models.CorsWhitelist{}).
+			Where("is_active = ?", true).
+			Pluck("origin", &origins).Error
+	}
+	if dbErr != nil {
+		return nil, dbErr
+	}
+
+	for _, origin := range origins {
+		out[strings.ToLower(strings.TrimSpace(origin))] = true
+	}
+
+	cacheBytes, _ := json.Marshal(origins)
+	_ = database.SetEx(cacheKey, string(cacheBytes), corsCacheTTLSeconds)
+
+	return out, nil
+}
+
+func corsLogf(format string, args ...interface{}) {
+	if configs.AppConfig != nil && configs.AppConfig.CorsDebug {
+		log.Printf(format, args...)
+	}
+}