Pillow/Tests/check_png_dos.py
2024-01-21 14:38:17 +11:00

63 lines
1.5 KiB
Python

from __future__ import annotations
import zlib
from io import BytesIO
from PIL import Image, ImageFile, PngImagePlugin
TEST_FILE = "Tests/images/png_decompression_dos.png"
def test_ignore_dos_text() -> None:
ImageFile.LOAD_TRUNCATED_IMAGES = True
try:
im = Image.open(TEST_FILE)
im.load()
finally:
ImageFile.LOAD_TRUNCATED_IMAGES = False
for s in im.text.values():
assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
for s in im.info.values():
assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
def test_dos_text() -> None:
try:
im = Image.open(TEST_FILE)
im.load()
except ValueError as msg:
assert msg, "Decompressed Data Too Large"
return
for s in im.text.values():
assert len(s) < 1024 * 1024, "Text chunk larger than 1M"
def test_dos_total_memory() -> None:
im = Image.new("L", (1, 1))
compressed_data = zlib.compress(b"a" * 1024 * 1023)
info = PngImagePlugin.PngInfo()
for x in range(64):
info.add_text(f"t{x}", compressed_data, zip=True)
info.add_itxt(f"i{x}", compressed_data, zip=True)
b = BytesIO()
im.save(b, "PNG", pnginfo=info)
b.seek(0)
try:
im2 = Image.open(b)
except ValueError as msg:
assert "Too much memory" in str(msg)
return
total_len = 0
for txt in im2.text.values():
total_len += len(txt)
assert total_len < 64 * 1024 * 1024, "Total text chunks greater than 64M"