Add --max-image-mpixels argument to support Pillow 5.0

docs/release_notes.rst

@@ -5,6 +5,15 @@ OCRmyPDF uses `semantic versioning <http://semver.org/>`_ for its command line i
 
 The OCRmyPDF package itself does not contain a public API, although it is fairly stable and breaking changes are usually timed with a major release. A future release will clearly define the stable public API.
 
+v5.5
+----
+
+-   Add new argument ``--max-image-mpixels``. Pillow 5.0 now raises an exception when images may be decompression bombs. This argument can be used to override the limit Pillow sets.
+-   Fix output page cropped when using the sandwich renderer and OCR is skipped on a rotated and image-processed page
+-   A warning is now issued when old versions of Ghostscript are used in cases known to cause issues with non-Latin characters
+-   Fix a few parameter validation checks for ``-output-type pdfa-1`` and ``pdfa-2`` 
+
+
 v5.4.4
 ------
 

ocrmypdf/__main__.py

@@ -14,6 +14,7 @@ import logging
 import argparse
 
 import PyPDF2 as pypdf
+import PIL
 
 import ruffus.ruffus_exceptions as ruffus_exceptions
 import ruffus.cmdline as cmdline
@@ -241,6 +242,11 @@ ocrsettings.add_argument(
 advanced = parser.add_argument_group(
     "Advanced",
     "Advanced options to control Tesseract's OCR behavior")
+advanced.add_argument(
+    '--max-image-mpixels', action='store', type=float, metavar='MPixels',
+    help="Set maximum number of pixels to unpack before treating an image as a "
+         "decompression bomb",
+    default=128.0)
 advanced.add_argument(
     '--tesseract-config', action='append', metavar='CFG', default=[],
     help="Additional Tesseract configuration files -- see documentation")
@@ -598,6 +604,12 @@ def do_ruffus_exception(ruffus_five_tuple, options, log):
 
             """))
         exit_code = ExitCode.encrypted_pdf
+    elif exc_name == 'PIL.Image.DecompressionBombError':
+        msg = cleanup_ruffus_error_message(exc_value)
+        msg += ("\nUse the --max-image-mpixels argument to set increase the "
+                "maximum number of megapixels to accept.")
+        log.error(msg)
+        exit_code = ExitCode.input_file
 
     if exit_code is not None:
         return exit_code
@@ -697,6 +709,10 @@ def run_pipeline():
 
     check_options(options, _log)
 
+    PIL.Image.MAX_IMAGE_PIXELS = int(options.max_image_mpixels * 1000000)
+    if PIL.Image.MAX_IMAGE_PIXELS == 0:
+        PIL.Image.MAX_IMAGE_PIXELS = None
+
     # Complain about qpdf version < 7.0.0
     # Suppress the warning if in the test suite, since there are no PPAs
     # for qpdf 7.0.0 for Ubuntu trusty (i.e. Travis)

tests/test_main.py

@@ -14,6 +14,8 @@ from ocrmypdf.exec import ghostscript, tesseract, qpdf
 import logging
 from math import isclose
 
+import PIL
+
 
 check_ocrmypdf = pytest.helpers.check_ocrmypdf
 run_ocrmypdf = pytest.helpers.run_ocrmypdf
@@ -1059,4 +1061,22 @@ def test_rotate_deskew_timeout(resources, outdir):
         test_pageno=1)
 
     # Confirm that the page still got deskewed
-    assert correlation > 0.50
+    assert correlation > 0.50
+
+
+@pytest.mark.skipif(
+    PIL.PILLOW_VERSION < '5.0.0',
+    reason="Pillow < 5.0.0 doesn't raise the exception")
+def test_decompression_bomb(resources, outpdf):
+    p, out, err = run_ocrmypdf(
+        resources / 'hugemono.pdf',
+        outpdf
+    )
+    assert 'decompression bomb' in err
+
+    p, out, err = run_ocrmypdf(
+        resources / 'hugemono.pdf',
+        outpdf,
+        '--max-image-mpixels', '2000'
+    )
+    assert p.returncode == 0