4595N/AFix to upstream bug

4595N/A

4595N/APatch based on upstream commit to Pillow 2.7.0 (PIL fork)

4595N/A

4595N/ANote that this patch includes a test of the fix, which requires an

4595N/Aimage file which is copied in from files/png_decompress_dos.png,

4595N/Asince it cannot be patched in.

4595N/A

4595N/A--- Imaging-1.1.7-orig/PIL/PngImagePlugin.py 2015-01-21 17:45:12.000000000 -0800

4595N/A+++ Imaging-1.1.7/PIL/PngImagePlugin.py 2015-01-21 19:37:23.000000000 -0800

4595N/A@@ -68,6 +68,12 @@ _MODES = {

4595N/A (16,6): ("RGBA", "RGBA;16B"),

4595N/A }

4595N/A

4595N/A+def _safe_zlib_decompress(s):

4595N/A+ dobj = zlib.decompressobj()

4595N/A+ plaintext = dobj.decompress(s, ImageFile.SAFEBLOCK)

4595N/A+ if dobj.unconsumed_tail:

4595N/A+ raise ValueError("Decompressed Data Too Large")

4595N/A+ return plaintext

4595N/A

4595N/A # --------------------------------------------------------------------

4595N/A # Support classes. Suitable for PNG and related formats like MNG etc.

4595N/A@@ -197,7 +203,7 @@ class PngStream(ChunkStream):

4595N/A if comp_method != 0:

4595N/A raise SyntaxError("Unknown compression method %s in iCCP chunk" % comp_method)

4595N/A try:

4595N/A- icc_profile = zlib.decompress(s[i+2:])

4595N/A+ icc_profile = _safe_zlib_decompress(s[i+2:])

4595N/A except zlib.error:

4595N/A icc_profile = None # FIXME

4595N/A self.im_info["icc_profile"] = icc_profile

4595N/A@@ -293,7 +299,7 @@ class PngStream(ChunkStream):

4595N/A if comp_method != 0:

4595N/A raise SyntaxError("Unknown compression method %s in zTXt chunk" % comp_method)

4595N/A import zlib

4595N/A- self.im_info[k] = self.im_text[k] = zlib.decompress(v[1:])

4595N/A+ self.im_info[k] = self.im_text[k] = _safe_zlib_decompress(v[1:])

4595N/A return s

4595N/A

4595N/A # --------------------------------------------------------------------

4595N/A--- Imaging-1.1.7-orig/selftest.py 2015-01-21 17:44:51.000000000 -0800

4595N/A+++ Imaging-1.1.7/selftest.py 2015-07-02 17:06:23.636751412 -0700

4595N/A@@ -9,6 +9,7 @@ from PIL import Image

4595N/A from PIL import ImageDraw

4595N/A from PIL import ImageFilter

4595N/A from PIL import ImageMath

4595N/A+from PIL import PngImagePlugin

4595N/A

4595N/A try:

4595N/A Image.core.ping

4595N/A@@ -146,6 +147,15 @@ def testimage():

4595N/A >>> im.mode, im.size

4595N/A ('F', (128, 128))

4595N/A

4595N/A+ Test fix to PNG decompression DOS #1060

4595N/A+

4595N/A+ >>> try:

4595N/A+ ... im = Image.open("Images/png_decompression_dos.png")

4595N/A+ ... im.load()

4595N/A+ ... except ValueError as msg:

4595N/A+ ... print msg

4595N/A+ Decompressed Data Too Large

4595N/A+

4595N/A PIL can do many other things, but I'll leave that for another

4595N/A day. If you're curious, check the handbook, available from:

4595N/A