Issue #1159051: GzipFile now raises EOFError when reading a corrupted file
with truncated header or footer.
Added tests for reading truncated gzip, bzip2, and lzma files.
diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index 912fac1..df7e18c 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -577,6 +577,20 @@
bz2f.seek(-150, 1)
self.assertEqual(bz2f.read(), self.TEXT[500-150:])
+ def test_read_truncated(self):
+ # Drop the eos_magic field (6 bytes) and CRC (4 bytes).
+ truncated = self.DATA[:-10]
+ with BZ2File(BytesIO(truncated)) as f:
+ self.assertRaises(EOFError, f.read)
+ with BZ2File(BytesIO(truncated)) as f:
+ self.assertEqual(f.read(len(self.TEXT)), self.TEXT)
+ self.assertRaises(EOFError, f.read, 1)
+ # Incomplete 4-byte file header, and block header of at least 146 bits.
+ for i in range(22):
+ with BZ2File(BytesIO(truncated[:i])) as f:
+ self.assertRaises(EOFError, f.read, 1)
+
+
class BZ2CompressorTest(BaseTest):
def testCompress(self):
bz2c = BZ2Compressor()
diff --git a/Lib/test/test_gzip.py b/Lib/test/test_gzip.py
index af73953..ebd4c43 100644
--- a/Lib/test/test_gzip.py
+++ b/Lib/test/test_gzip.py
@@ -389,6 +389,20 @@
datac = gzip.compress(data)
self.assertEqual(gzip.decompress(datac), data)
+ def test_read_truncated(self):
+ data = data1*50
+ # Drop the CRC (4 bytes) and file size (4 bytes).
+ truncated = gzip.compress(data)[:-8]
+ with gzip.GzipFile(fileobj=io.BytesIO(truncated)) as f:
+ self.assertRaises(EOFError, f.read)
+ with gzip.GzipFile(fileobj=io.BytesIO(truncated)) as f:
+ self.assertEqual(f.read(len(data)), data)
+ self.assertRaises(EOFError, f.read, 1)
+ # Incomplete 10-byte header.
+ for i in range(2, 10):
+ with gzip.GzipFile(fileobj=io.BytesIO(truncated[:i])) as f:
+ self.assertRaises(EOFError, f.read, 1)
+
class TestOpen(BaseTest):
def test_binary_modes(self):
diff --git a/Lib/test/test_lzma.py b/Lib/test/test_lzma.py
index a13cf3b..4669ee2 100644
--- a/Lib/test/test_lzma.py
+++ b/Lib/test/test_lzma.py
@@ -669,6 +669,20 @@
with LZMAFile(BytesIO(COMPRESSED_XZ[:128])) as f:
self.assertRaises(EOFError, f.read)
+ def test_read_truncated(self):
+ # Drop stream footer: CRC (4 bytes), index size (4 bytes),
+ # flags (2 bytes) and magic number (2 bytes).
+ truncated = COMPRESSED_XZ[:-12]
+ with LZMAFile(BytesIO(truncated)) as f:
+ self.assertRaises(EOFError, f.read)
+ with LZMAFile(BytesIO(truncated)) as f:
+ self.assertEqual(f.read(len(INPUT)), INPUT)
+ self.assertRaises(EOFError, f.read, 1)
+ # Incomplete 12-byte header.
+ for i in range(12):
+ with LZMAFile(BytesIO(truncated[:i])) as f:
+ self.assertRaises(EOFError, f.read, 1)
+
def test_read_bad_args(self):
f = LZMAFile(BytesIO(COMPRESSED_XZ))
f.close()