Merge pull request #217 from abhinavxd/feat-fs-urls

feat: Signed URL support for filesystem store

cmd/handlers.go

@@ -26,8 +26,8 @@ func initHandlers(g *fastglue.Fastglue, hub *ws.Hub) {
 	// Public config for app initialization.
 	g.GET("/api/v1/config", handleGetConfig)
 
-	// Media.
-	g.GET("/uploads/{uuid}", auth(handleServeMedia))
+	// Media - supports both authenticated access and signed URLs.
+	g.GET("/uploads/{uuid}", authOrSignedURL(handleServeMedia))
 	g.POST("/api/v1/media", auth(handleMediaUpload))
 
 	// Settings.

cmd/init.go

@@ -480,6 +480,11 @@ func initMedia(db *sqlx.DB, i18n *i18n.I18n, settings *setting.Manager) *media.M
 			log.Fatalf("error initializing s3 media store: %v", err)
 		}
 	case "fs":
+		// Default expiry to 1h if not set.
+		fsExpiry := ko.Duration("upload.fs.expiry")
+		if fsExpiry == 0 {
+			fsExpiry = 1 * time.Hour
+		}
 		store, err = fs.New(fs.Opts{
 			UploadURI:  "/uploads",
 			UploadPath: filepath.Clean(ko.String("upload.fs.upload_path")),
@@ -491,6 +496,8 @@ func initMedia(db *sqlx.DB, i18n *i18n.I18n, settings *setting.Manager) *media.M
 				}
 				return rootURL
 			},
+			SigningKey: ko.MustString("app.encryption_key"),
+			Expiry:     fsExpiry,
 		})
 		if err != nil {
 			log.Fatalf("error initializing fs media store: %v", err)

cmd/media.go

@@ -13,6 +13,7 @@ import (
 	amodels "github.com/abhinavxd/libredesk/internal/auth/models"
 	"github.com/abhinavxd/libredesk/internal/envelope"
 	"github.com/abhinavxd/libredesk/internal/image"
+	mmodels "github.com/abhinavxd/libredesk/internal/media/models"
 	"github.com/abhinavxd/libredesk/internal/stringutil"
 	"github.com/google/uuid"
 	"github.com/valyala/fasthttp"
@@ -148,20 +149,29 @@ func handleMediaUpload(r *fastglue.Request) error {
 }
 
 // handleServeMedia serves uploaded media.
+// Supports both authenticated access (with permission checks) and signed URL access (no permission checks).
 func handleServeMedia(r *fastglue.Request) error {
 	var (
-		app   = r.Context.(*App)
-		auser = r.RequestCtx.UserValue("user").(amodels.User)
-		uuid  = r.RequestCtx.UserValue("uuid").(string)
+		app  = r.Context.(*App)
+		uuid = r.RequestCtx.UserValue("uuid").(string)
+		authMethod = r.RequestCtx.UserValue("auth_method")
 	)
 
+	// If accessed via signed URL, skip permission checks and serve file directly.
+	if authMethod == "signed_url" {
+		return serveMediaFile(r, app, uuid, nil)
+	}
+
+	// Session/API key authenticated - perform full permission check.
+	auser := r.RequestCtx.UserValue("user").(amodels.User)
+
 	user, err := app.user.GetAgent(auser.ID, "")
 	if err != nil {
 		return sendErrorEnvelope(r, err)
 	}
 
 	// Fetch media from DB.
-	media, err := app.media.Get(0, strings.TrimPrefix(uuid, image.ThumbPrefix))
+	media, err := getMediaByUUID(app, uuid)
 	if err != nil {
 		return sendErrorEnvelope(r, err)
 	}
@@ -187,6 +197,22 @@ func handleServeMedia(r *fastglue.Request) error {
 	if !allowed {
 		return r.SendErrorEnvelope(http.StatusUnauthorized, app.i18n.Ts("globals.messages.denied", "name", "{globals.terms.permission}"), nil, envelope.UnauthorizedError)
 	}
+
+	return serveMediaFile(r, app, uuid, &media)
+}
+
+// serveMediaFile serves the actual file content based on the storage provider.
+// If media is nil, it will be fetched from DB.
+func serveMediaFile(r *fastglue.Request, app *App, uuid string, media *mmodels.Media) error {
+	// Fetch media metadata from DB if not provided.
+	if media == nil {
+		m, err := getMediaByUUID(app, uuid)
+		if err != nil {
+			return sendErrorEnvelope(r, err)
+		}
+		media = &m
+	}
+
 	consts := app.consts.Load().(*constants)
 	switch consts.UploadProvider {
 	case "fs":
@@ -213,3 +239,8 @@ func handleServeMedia(r *fastglue.Request) error {
 func bytesToMegabytes(bytes int64) float64 {
 	return float64(bytes) / 1024 / 1024
 }
+
+// getMediaByUUID fetches media metadata from DB, handling thumbnail prefix.
+func getMediaByUUID(app *App, uuid string) (mmodels.Media, error) {
+	return app.media.Get(0, strings.TrimPrefix(uuid, image.ThumbPrefix))
+}

cmd/middlewares.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"net/http"
+	"strconv"
 	"strings"
 
 	amodels "github.com/abhinavxd/libredesk/internal/auth/models"
@@ -220,3 +221,61 @@ func notAuthPage(handler fastglue.FastRequestHandler) fastglue.FastRequestHandle
 		return handler(r)
 	}
 }
+
+// authOrSignedURL allows access if user is authenticated OR if URL has valid signature.
+// Used for media endpoints that support both access methods.
+func authOrSignedURL(handler fastglue.FastRequestHandler) fastglue.FastRequestHandler {
+	return func(r *fastglue.Request) error {
+		app := r.Context.(*App)
+
+		// First, try to authenticate normally.
+		user, err := authenticateUser(r, app)
+		if err == nil && user.ID > 0 {
+			// User is authenticated, set user context and proceed.
+			r.RequestCtx.SetUserValue("user", amodels.User{
+				ID:        user.ID,
+				Email:     user.Email.String,
+				FirstName: user.FirstName,
+				LastName:  user.LastName,
+			})
+			r.RequestCtx.SetUserValue("auth_method", "session")
+			return handler(r)
+		}
+
+		// Authentication failed, check for signed URL.
+		validator := app.media.SignedURLValidator()
+		if validator == nil {
+			// Store doesn't support signed URLs, require auth.
+			return r.SendErrorEnvelope(http.StatusUnauthorized,
+				app.i18n.T("auth.invalidOrExpiredSession"), nil, envelope.GeneralError)
+		}
+
+		// Parse signature and expiry from query params.
+		sig := string(r.RequestCtx.QueryArgs().Peek("sig"))
+		expStr := string(r.RequestCtx.QueryArgs().Peek("exp"))
+
+		if sig == "" || expStr == "" {
+			return r.SendErrorEnvelope(http.StatusUnauthorized,
+				app.i18n.T("auth.invalidOrExpiredSession"), nil, envelope.GeneralError)
+		}
+
+		exp, err := strconv.ParseInt(expStr, 10, 64)
+		if err != nil {
+			return r.SendErrorEnvelope(http.StatusBadRequest,
+				app.i18n.Ts("globals.messages.invalid", "name", "expiry"), nil, envelope.InputError)
+		}
+
+		// Get the UUID from the route.
+		uuid := r.RequestCtx.UserValue("uuid").(string)
+
+		// Validate signature.
+		if !validator(uuid, sig, exp) {
+			return r.SendErrorEnvelope(http.StatusForbidden,
+				app.i18n.T("media.invalidOrExpiredURL"), nil, envelope.PermissionError)
+		}
+
+		// Mark as signed URL access (no user context).
+		r.RequestCtx.SetUserValue("auth_method", "signed_url")
+		return handler(r)
+	}
+}

i18n/en.json

@@ -355,6 +355,7 @@
   "media.fileSizeTooLarge": "File size too large, please upload a file less than {size} ",
   "media.fileTypeNotAllowed": "File type not allowed",
   "media.fileEmpty": "This file is 0 bytes, so it will not be attached.",
+  "media.invalidOrExpiredURL": "Invalid or expired media URL",
   "inbox.emptyIMAP": "Empty IMAP config",
   "inbox.emptySMTP": "Empty SMTP config",
   "inbox.oauthAlreadyExists": "An inbox with this email already exists. Use Reconnect to update credentials.",

internal/media/media.go

@@ -37,6 +37,9 @@ type Store interface {
 	GetURL(name, disposition, fileName string) string
 	GetBlob(name string) ([]byte, error)
 	Name() string
+	// SignedURLValidator returns a validator function if the store supports signed URLs.
+	// Returns nil if the store doesn't use signed URLs (e.g., S3 handles validation itself).
+	SignedURLValidator() func(name, sig string, exp int64) bool
 }
 
 type Manager struct {
@@ -175,6 +178,12 @@ func (m *Manager) GetURL(uuid, contentType, fileName string) string {
 	return m.store.GetURL(uuid, disposition, fileName)
 }
 
+// SignedURLValidator returns the store's signature validator if available.
+// Returns nil if the store doesn't support signed URL validation.
+func (m *Manager) SignedURLValidator() func(name, sig string, exp int64) bool {
+	return m.store.SignedURLValidator()
+}
+
 // Attach associates a media file with a specific model by its ID and model name.
 func (m *Manager) Attach(id int, model string, modelID int) error {
 	if _, err := m.queries.Attach.Exec(id, model, modelID); err != nil {

internal/media/stores/localfs/fs.go

@@ -1,10 +1,14 @@
 package fs
 
 import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/base64"
 	"fmt"
 	"io"
 	"os"
 	"path/filepath"
+	"time"
 
 	"github.com/abhinavxd/libredesk/internal/media"
 )
@@ -14,6 +18,8 @@ type Opts struct {
 	UploadPath string
 	UploadURI  string
 	RootURL    func() string
+	SigningKey string        // HMAC signing key for generating signed URLs.
+	Expiry     time.Duration // URL expiry duration.
 }
 
 // Client implements `media.Store`
@@ -48,8 +54,47 @@ func (c *Client) Put(filename string, cType string, src io.ReadSeeker) (string,
 }
 
 // GetURL accepts a filename and retrieves the full URL for file.
+// If a signing key is configured, returns a signed URL with expiry.
 func (c *Client) GetURL(name, _, _ string) string {
-	return fmt.Sprintf("%s%s/%s", c.opts.RootURL(), c.opts.UploadURI, name)
+	// If no signing key configured, return unsigned URL.
+	if c.opts.SigningKey == "" {
+		return fmt.Sprintf("%s%s/%s", c.opts.RootURL(), c.opts.UploadURI, name)
+	}
+	return c.signURL(name)
+}
+
+// signURL generates a signed URL with expiry timestamp.
+func (c *Client) signURL(name string) string {
+	exp := time.Now().Add(c.opts.Expiry).Unix()
+	sig := c.generateSignature(name, exp)
+	return fmt.Sprintf("%s%s/%s?sig=%s&exp=%d", c.opts.RootURL(), c.opts.UploadURI, name, sig, exp)
+}
+
+// generateSignature creates HMAC-SHA256 signature for the given name and expiry.
+func (c *Client) generateSignature(name string, exp int64) string {
+	message := fmt.Sprintf("%s:%d", name, exp)
+	h := hmac.New(sha256.New, []byte(c.opts.SigningKey))
+	h.Write([]byte(message))
+	return base64.RawURLEncoding.EncodeToString(h.Sum(nil))
+}
+
+// ValidateSignature verifies the signature and expiry of a signed URL.
+// Returns true if the signature is valid and the URL has not expired.
+func (c *Client) ValidateSignature(name, sig string, exp int64) bool {
+	if time.Now().Unix() > exp {
+		return false
+	}
+	expectedSig := c.generateSignature(name, exp)
+	return hmac.Equal([]byte(sig), []byte(expectedSig))
+}
+
+// SignedURLValidator returns a validator function if the store supports signed URLs.
+// Returns nil if the store doesn't use signed URLs (no signing key configured).
+func (c *Client) SignedURLValidator() func(name, sig string, exp int64) bool {
+	if c.opts.SigningKey == "" {
+		return nil
+	}
+	return c.ValidateSignature
 }
 
 // GetBlob accepts a URL, reads the file, and returns the blob.

internal/media/stores/s3/s3.go

@@ -162,3 +162,9 @@ func (c *Client) makeFileURL(name string) string {
 func (c *Client) Name() string {
 	return "s3"
 }
+
+// SignedURLValidator returns nil as S3 handles its own presigned URL validation.
+// The S3 service validates presigned URLs when they are accessed.
+func (c *Client) SignedURLValidator() func(name, sig string, exp int64) bool {
+	return nil
+}