1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
|
from chrysacase import ChrysalideTestCase
from pychrysalide.common import pack_uleb128, unpack_uleb128, pack_leb128, unpack_leb128
from pychrysalide.common import PackedBuffer
class TestLEB128Values(ChrysalideTestCase):
"""TestCase for common LEB128 features*"""
def testUnsignedLeb128Encoding(self):
"""Pack and unpack unsigned LEB128 values."""
cases = {
624485: b'\xe5\x8e\x26',
127: b'\x7f',
128: b'\x80\x01',
}
for value, encoding in cases.items():
pbuf = PackedBuffer()
status = pack_uleb128(value, pbuf)
self.assertTrue(status)
self.assertEqual(pbuf.payload_length, len(encoding))
pbuf.rewind()
got = pbuf.extract(len(encoding))
self.assertEqual(got, encoding)
self.assertFalse(pbuf.more_data)
for value, encoding in cases.items():
pbuf = PackedBuffer()
pbuf.extend(encoding, False)
pbuf.rewind()
got = unpack_uleb128(pbuf)
self.assertIsNotNone(got)
self.assertEqual(got, value)
def testSignedLeb128Encoding(self):
"""Pack and unpack signed LEB128 values."""
cases = {
-123456: b'\xc0\xbb\x78',
-42: b'\x56',
-9001: b'\xd7\xb9\x7f',
}
for value, encoding in cases.items():
pbuf = PackedBuffer()
status = pack_leb128(value, pbuf)
self.assertTrue(status)
self.assertEqual(pbuf.payload_length, len(encoding))
pbuf.rewind()
got = pbuf.extract(len(encoding))
self.assertEqual(got, encoding)
self.assertFalse(pbuf.more_data)
for value, encoding in cases.items():
pbuf = PackedBuffer()
pbuf.extend(encoding, False)
pbuf.rewind()
got = unpack_leb128(pbuf)
self.assertIsNotNone(got)
self.assertEqual(got, value)
def testTooBigLeb128Encodings(self):
"""Prevent overflow for LEB128 values."""
pbuf = PackedBuffer()
pbuf.extend(b'\x80' * 10 + b'\x7f', False)
pbuf.rewind()
got = unpack_uleb128(pbuf)
self.assertIsNone(got)
pbuf = PackedBuffer()
pbuf.extend(b'\x80' * 10 + b'\x7f', False)
pbuf.rewind()
got = unpack_leb128(pbuf)
self.assertIsNone(got)
|
