Disallow start and end coordinates for encrypted files

api/sda/sda.go

@@ -156,6 +156,7 @@ func Download(c *gin.Context) {
 		c.String(http.StatusUnauthorized, "unauthorised")
 
 		return
+
 	}
 
 	// Get file header
@@ -166,6 +167,43 @@ func Download(c *gin.Context) {
 		return
 	}
 
+	// Get query params
+	qStart := c.DefaultQuery("startCoordinate", "0")
+	qEnd := c.DefaultQuery("endCoordinate", "0")
+
+	// Parse and verify coordinates are valid
+	start, err := strconv.ParseInt(qStart, 10, 0)
+
+	if err != nil {
+		log.Errorf("failed to convert start coordinate %d to integer, %s", start, err)
+		c.String(http.StatusBadRequest, "startCoordinate must be an integer")
+
+		return
+	}
+	end, err := strconv.ParseInt(qEnd, 10, 0)
+	if err != nil {
+		log.Errorf("failed to convert end coordinate %d to integer, %s", end, err)
+
+		c.String(http.StatusBadRequest, "endCoordinate must be an integer")
+
+		return
+	}
+	if end < start {
+		log.Errorf("endCoordinate=%d must be greater than startCoordinate=%d", end, start)
+
+		c.String(http.StatusBadRequest, "endCoordinate must be greater than startCoordinate")
+
+		return
+	}
+
+	if start == 0 && end == 0 {
+		c.Header("Content-Length", fmt.Sprint(fileDetails.DecryptedSize))
+	} else {
+		// Calculate how much we should read (if given)
+		togo := end - start
+		c.Header("Content-Length", fmt.Sprint(togo))
+	}
+
 	// Get archive file handle
 	file, err := Backend.NewFileReader(fileDetails.ArchivePath)
 	if err != nil {
@@ -195,65 +233,41 @@ func Download(c *gin.Context) {
 		return
 	}
 
-	// Stitch file and prepare it for streaming
-	var fileStream *streaming.Crypt4GHReader
+	// Prepare the file for streaming, encrypted or decrypted
+	var encryptedFileReader io.Reader
+	var fileStream io.Reader
+	hr := bytes.NewReader(fileDetails.Header)
+	encryptedFileReader = io.MultiReader(hr, file)
+
 	switch c.Param("type") {
 	case "encrypted":
-		log.Print("Return encrypted file")
-		fileStream, err = stitchEncryptedFile(fileDetails.Header, file)
-		if err != nil {
-			log.Errorf("could not prepare file for streaming, %s", err)
-			c.String(http.StatusInternalServerError, "file stream error")
+		if start > 0 || end > 0 {
+			// unset content-length
+			c.Header("Content-Length", "-1")
+			log.Errorf("Start and end coordinates for encrypted files not implemented! %v", start)
+			c.String(http.StatusInternalServerError, "an error occurred")
 
 			return
 		}
-		c.Header("Content-Length", "")
+		fileStream = encryptedFileReader
+
 	default:
-		// Stitch file and prepare it for streaming
-		fileStream, err = stitchFile(fileDetails.Header, file)
+		c4ghfileStream, err := streaming.NewCrypt4GHReader(encryptedFileReader, *config.Config.App.Crypt4GHKey, nil)
+		defer c4ghfileStream.Close()
 		if err != nil {
 			log.Errorf("could not prepare file for streaming, %s", err)
 			c.String(http.StatusInternalServerError, "file stream error")
 
 			return
 		}
-	}
-
-	// Get query params
-	qStart := c.DefaultQuery("startCoordinate", "0")
-	qEnd := c.DefaultQuery("endCoordinate", "0")
-
-	// Parse and verify coordinates are valid
-	start, err := strconv.ParseInt(qStart, 10, 0)
-
-	if err != nil {
-		log.Errorf("failed to convert start coordinate %d to integer, %s", start, err)
-		c.String(http.StatusBadRequest, "startCoordinate must be an integer")
-
-		return
-	}
-	end, err := strconv.ParseInt(qEnd, 10, 0)
-	if err != nil {
-		log.Errorf("failed to convert end coordinate %d to integer, %s", end, err)
-
-		c.String(http.StatusBadRequest, "endCoordinate must be an integer")
-
-		return
-	}
-	if end < start {
-		log.Errorf("endCoordinate=%d must be greater than startCoordinate=%d", end, start)
-
-		c.String(http.StatusBadRequest, "endCoordinate must be greater than startCoordinate")
-
-		return
-	}
+		err = truncateStream(c4ghfileStream, c.Writer, start)
+		fileStream = c4ghfileStream
+		if err != nil {
+			log.Errorf("error occurred while finding sending start: %v", err)
+			c.String(http.StatusInternalServerError, "an error occurred")
 
-	if start == 0 && end == 0 {
-		c.Header("Content-Length", fmt.Sprint(fileDetails.DecryptedSize))
-	} else {
-		// Calculate how much we should read (if given)
-		togo := end - start
-		c.Header("Content-Length", fmt.Sprint(togo))
+			return
+		}
 	}
 
 	err = sendStream(fileStream, c.Writer, start, end)
@@ -265,46 +279,19 @@ func Download(c *gin.Context) {
 	}
 }
 
-// stitchFile stitches the header and file body together for Crypt4GHReader
-// and returns a streamable Reader
-var stitchFile = func(header []byte, file io.ReadCloser) (*streaming.Crypt4GHReader, error) {
-	log.Debugf("stitching header to file %s for streaming", file)
-	// Stitch header and file body together
-	hr := bytes.NewReader(header)
-	mr := io.MultiReader(hr, file)
-
-	c4ghr, err := streaming.NewCrypt4GHReader(mr, *config.Config.App.Crypt4GHKey, nil)
-	//defer c4ghr.Close()
-	return c4ghr, err
-}
-
-// stitchEncryptedFile stitches the header and file body together for Crypt4GHReader
-// and returns a streamable Reader
-var stitchEncryptedFile = func(header []byte, file io.ReadCloser) (*streaming.Crypt4GHReader, error) {
-	log.Debugf("stitching header to file %s for streaming", file)
-	// Stitch header and file body together
-	hr := bytes.NewReader(header)
-
-	encryptedFile := io.MultiReader(hr, io.MultiReader(hr, file))
-
-	log.Print("Encrypted file:", encryptedFile)
-
-	log.Debugf("file stream for %s constructed", file)
-	c4ghr, err := streaming.NewCrypt4GHReader(encryptedFile, *config.Config.App.Crypt4GHKey, nil)
-
-	return c4ghr, err
-}
-
-// sendStream
-// used from: https://github.com/neicnordic/crypt4gh/blob/master/examples/reader/main.go#L48C1-L113C1
-var sendStream = func(reader *streaming.Crypt4GHReader, writer http.ResponseWriter, start, end int64) error {
+var truncateStream = func(reader *streaming.Crypt4GHReader, writer http.ResponseWriter, start int64) error {
 
 	if start != 0 {
 		// We don't want to read from start, skip ahead to where we should be
 		if _, err := reader.Seek(start, 0); err != nil {
 			return err
 		}
 	}
+	return nil
+}
+
+// used from: https://github.com/neicnordic/crypt4gh/blob/master/examples/reader/main.go#L48C1-L113C1
+var sendStream = func(reader io.Reader, writer http.ResponseWriter, start, end int64) error {
 
 	// Calculate how much we should read (if given)
 	togo := end - start