refactor: use internal PIL size limit as maximal file size limit

Co-authored-by: Clemens Langer<Clemens.Langer@heigit.org>

Author: matthiasschaub

sketch_map_tool/config.py

@@ -21,7 +21,6 @@
     "wms-layers-esri-world-imagery-fallback": "world_imagery_fallback",
     "wms-read-timeout": 600,
     "max-nr-simultaneous-uploads": 100,
-    "max_pixel_per_image": 10e8,  # 10.000*10.000
     "yolo_cls": "SMT-CLS",
     "yolo_osm_obj": "SMT-OSM",
     "yolo_esri_obj": "SMT-ESRI",

sketch_map_tool/validators.py

@@ -2,6 +2,7 @@
 from uuid import UUID
 
 import PIL.Image as Image
+from PIL.Image import MAX_IMAGE_PIXELS, DecompressionBombError
 from werkzeug.datastructures import FileStorage
 
 from sketch_map_tool import get_config_value
@@ -27,7 +28,6 @@ def validate_uploaded_sketchmaps(files: list[FileStorage]):
     """Validation function for uploaded files."""
 
     max_nr_simultaneous_uploads = int(get_config_value("max-nr-simultaneous-uploads"))
-    max_pixel_per_image = int(get_config_value("max_pixel_per_image"))
 
     if len(files) > max_nr_simultaneous_uploads:
         raise UploadLimitsExceededError(
@@ -38,16 +38,15 @@ def validate_uploaded_sketchmaps(files: list[FileStorage]):
         )
 
     for file in files:
-        img = Image.open(file)
-        total_pxl_cnt = img.size[0] * img.size[1]
-        if total_pxl_cnt > max_pixel_per_image:
+        try:
+            img = Image.open(file)
+        except DecompressionBombError as error:
             raise UploadLimitsExceededError(
                 N_(
-                    "You can only upload pictures up to "
-                    "a total pixel count of {MAX_PIXEL_PER_IMAGE}."
+                    "You can only upload pictures up to a total pixel count of "
+                    "{0} pixels.".format(MAX_IMAGE_PIXELS)
                 ),
-                {"MAX_PIXEL_PER_IMAGE": max_pixel_per_image},
-            )
+            ) from error
         del img
         file.seek(0)
 

tests/unit/test_config.py

@@ -33,7 +33,6 @@ def config_keys():
         "wms-layers-esri-world-imagery-fallback",
         "wms-read-timeout",
         "max-nr-simultaneous-uploads",
-        "max_pixel_per_image",
         "yolo_cls",
         "yolo_osm_obj",
         "yolo_esri_obj",

tests/unit/test_validators.py

@@ -1,8 +1,11 @@
+import PIL
 import pytest
 
+from sketch_map_tool.exceptions import UploadLimitsExceededError
 from sketch_map_tool.validators import (
     validate_bbox,
     validate_type,
+    validate_uploaded_sketchmaps,
     validate_uuid,
 )
 
@@ -40,3 +43,13 @@ def test_validate_bbox(bbox_wgs84_str):
 def test_validate_bbox_invalid(bbox_str_):
     with pytest.raises(ValueError):
         validate_bbox(bbox_str_)
+
+
+def test_validate_uploaded_sketchmaps(file):
+    before = PIL.Image.MAX_IMAGE_PIXELS
+    try:
+        PIL.Image.MAX_IMAGE_PIXELS = 1
+        with pytest.raises(UploadLimitsExceededError):
+            validate_uploaded_sketchmaps([file])
+    finally:
+        PIL.Image.MAX_IMAGE_PIXELS = before