Issue #21538: The plistlib module now supports loading of binary plist files
when reference or offset size is not a power of two.
diff --git a/Lib/plistlib.py b/Lib/plistlib.py
index dcb0f9c..8c148a8 100644
--- a/Lib/plistlib.py
+++ b/Lib/plistlib.py
@@ -619,10 +619,7 @@
offset_table_offset
) = struct.unpack('>6xBBQQQ', trailer)
self._fp.seek(offset_table_offset)
- offset_format = '>' + _BINARY_FORMAT[offset_size] * num_objects
- self._ref_format = _BINARY_FORMAT[self._ref_size]
- self._object_offsets = struct.unpack(
- offset_format, self._fp.read(offset_size * num_objects))
+ self._object_offsets = self._read_ints(num_objects, offset_size)
return self._read_object(self._object_offsets[top_object])
except (OSError, IndexError, struct.error):
@@ -638,9 +635,16 @@
return tokenL
+ def _read_ints(self, n, size):
+ data = self._fp.read(size * n)
+ if size in _BINARY_FORMAT:
+ return struct.unpack('>' + _BINARY_FORMAT[size] * n, data)
+ else:
+ return tuple(int.from_bytes(data[i: i + size], 'big')
+ for i in range(0, size * n, size))
+
def _read_refs(self, n):
- return struct.unpack(
- '>' + self._ref_format * n, self._fp.read(n * self._ref_size))
+ return self._read_ints(n, self._ref_size)
def _read_object(self, offset):
"""
diff --git a/Lib/test/test_plistlib.py b/Lib/test/test_plistlib.py
index bb7cc15..dc2fdf6 100644
--- a/Lib/test/test_plistlib.py
+++ b/Lib/test/test_plistlib.py
@@ -411,6 +411,18 @@
pl2 = plistlib.loads(data)
self.assertEqual(dict(pl), dict(pl2))
+ def test_nonstandard_refs_size(self):
+ # Issue #21538: Refs and offsets are 24-bit integers
+ data = (b'bplist00'
+ b'\xd1\x00\x00\x01\x00\x00\x02QaQb'
+ b'\x00\x00\x08\x00\x00\x0f\x00\x00\x11'
+ b'\x00\x00\x00\x00\x00\x00'
+ b'\x03\x03'
+ b'\x00\x00\x00\x00\x00\x00\x00\x03'
+ b'\x00\x00\x00\x00\x00\x00\x00\x00'
+ b'\x00\x00\x00\x00\x00\x00\x00\x13')
+ self.assertEqual(plistlib.loads(data), {'a': 'b'})
+
class TestPlistlibDeprecated(unittest.TestCase):
def test_io_deprecated(self):