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Verifying that data entry url box URLs are null terminated. #175

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This commit is contained in:
John Evans 2014-02-25 07:15:12 -05:00
commit 99d1a584d8
2 changed files with 29 additions and 2 deletions
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9
glymur/jp2box.py
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@ -2788,13 +2788,18 @@ class DataEntryURLBox(Jp2kBox):
def write(self, fptr):
"""Write a data entry url box to file.
"""
length = 8 + 1 + 3 + len(self.url.encode())
# Make sure it is written out as null-terminated.
url = self.url
if self.url[-1] != chr(0):
url = url + chr(0)
length = 8 + 1 + 3 + len(url.encode())
write_buffer = struct.pack('>I4sBBBB',
length, self.box_id.encode(),
self.version,
self.flag[0], self.flag[1], self.flag[2])
fptr.write(write_buffer)
fptr.write(self.url.encode())
fptr.write(url.encode())
def __repr__(self):

22
glymur/test/test_jp2box.py
View file

@ -77,6 +77,28 @@ class TestDataEntryURL(unittest.TestCase):
self.assertEqual(jp22.box[4].flag, (0, 0, 0))
self.assertEqual(jp22.box[4].url, url)
def test_null_termination(self):
"""I.9.3.2 specifies that the location field must be null terminated."""
jp2 = Jp2k(self.jp2file)
url = 'http://glymur.readthedocs.org'
deurl = glymur.jp2box.DataEntryURLBox(0, (0, 0, 0), url)
boxes = [box for box in jp2.box if box.box_id != 'uuid']
boxes.append(deurl)
with tempfile.NamedTemporaryFile(suffix=".jp2") as tfile:
jp22 = jp2.wrap(tfile.name, boxes=boxes)
self.assertEqual(jp22.box[-1].length, 42)
# Go to the last box. Seek past the L, T, version, and flag fields.
with open(tfile.name, 'rb') as fptr:
fptr.seek(jp22.box[-1].offset + 4 + 4 + 1 + 3)
nbytes = jp22.box[-1].offset + jp22.box[-1].length - fptr.tell()
read_buffer = fptr.read(nbytes)
read_url = read_buffer.decode('utf-8')
self.assertEqual(url + chr(0), read_url)
@unittest.skipIf(glymur.version.openjpeg_version_tuple[0] < 2 or
OPENJP2_IS_V2_OFFICIAL,