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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
from __future__ import unicode_literals
import struct
from awdb.compat import byte_from_int, int_from_byte, int_from_bytes
from awdb.errors import InvalidDatabaseError
class Decoder(object):
def __init__(self, database_buffer, pointer_base=0, pointer_test=False):
self._pointer_test = pointer_test
self._buffer = database_buffer
self._pointer_base = pointer_base
def _decode_array(self, size, offset):
array = []
for _ in range(size):
(value, offset) = self.decode(offset)
array.append(value)
return array, offset
def _decode_boolean(self, size, offset):
return size != 0, offset
def _decode_bytes(self, size, offset):
new_offset = offset + size
return self._buffer[offset:new_offset], new_offset
def _decode_double(self, size, offset):
self._verify_size(size, 8)
new_offset = offset + size
packed_bytes = self._buffer[offset:new_offset]
(value, ) = struct.unpack(b'!d', packed_bytes)
return value, new_offset
def _decode_float(self, size, offset):
self._verify_size(size, 4)
new_offset = offset + size
packed_bytes = self._buffer[offset:new_offset]
(value, ) = struct.unpack(b'!f', packed_bytes)
return value, new_offset
def _decode_int32(self, size, offset):
if size == 0:
return 0, offset
new_offset = offset + size
packed_bytes = self._buffer[offset:new_offset]
if size != 4:
packed_bytes = packed_bytes.rjust(4, b'\x00')
(value, ) = struct.unpack(b'!i', packed_bytes)
return value, new_offset
def _decode_map(self, size, offset):
container = {}
for _ in range(size):
(key, offset) = self.decode(offset)
(value, offset) = self.decode(offset)
if key == value:
container[key] = bytes(value, 'utf-8')
else:
container[key] = value
# print("###")
# print(container)
# print("###")
return container, offset
def _decode_pointer(self, size, offset):
pointer_size = (size >> 3) + 1
buf = self._buffer[offset:offset + pointer_size]
new_offset = offset + pointer_size
if pointer_size == 1:
buf = byte_from_int(size & 0x7) + buf
pointer = struct.unpack(b'!H', buf)[0] + self._pointer_base
elif pointer_size == 2:
buf = b'\x00' + byte_from_int(size & 0x7) + buf
pointer = struct.unpack(b'!I', buf)[0] + 2048 + self._pointer_base
elif pointer_size == 3:
buf = byte_from_int(size & 0x7) + buf
pointer = struct.unpack(b'!I',
buf)[0] + 526336 + self._pointer_base
else:
pointer = struct.unpack(b'!I', buf)[0] + self._pointer_base
if self._pointer_test:
return pointer, new_offset
(value, _) = self.decode(pointer)
return value, new_offset
def _decode_uint(self, size, offset):
new_offset = offset + size
uint_bytes = self._buffer[offset:new_offset]
return int_from_bytes(uint_bytes), new_offset
def _decode_utf8_string(self, size, offset):
new_offset = offset + size
return self._buffer[offset:new_offset].decode('utf-8'), new_offset
_type_decoder = {
1: _decode_pointer,
2: _decode_utf8_string,
3: _decode_double,
4: _decode_bytes,
5: _decode_uint,
6: _decode_uint,
7: _decode_map,
8: _decode_int32,
9: _decode_uint,
10: _decode_uint,
11: _decode_array,
14: _decode_boolean,
15: _decode_float,
}
def decode(self, offset):
new_offset = offset + 1
ctrl_byte = int_from_byte(self._buffer[offset])
type_num = ctrl_byte >> 5
if not type_num:
(type_num, new_offset) = self._read_extended(new_offset)
try:
decoder = self._type_decoder[type_num]
except KeyError:
raise InvalidDatabaseError('Unexpected type number ({type}) '
'encountered'.format(type=type_num))
(size, new_offset) = self._size_from_ctrl_byte(ctrl_byte, new_offset,
type_num)
return decoder(self, size, new_offset)
def _read_extended(self, offset):
next_byte = int_from_byte(self._buffer[offset])
type_num = next_byte + 7
if type_num < 7:
raise InvalidDatabaseError(
'Something went horribly wrong in the decoder. An '
'extended type resolved to a type number < 8 '
'({type})'.format(type=type_num))
return type_num, offset + 1
def _verify_size(self, expected, actual):
if expected != actual:
raise InvalidDatabaseError(
'The AW DB file\'s data section contains bad data '
'(unknown data type or corrupt data)')
def _size_from_ctrl_byte(self, ctrl_byte, offset, type_num):
size = ctrl_byte & 0x1f
if type_num == 1 or size < 29:
return size, offset
if size == 29:
size = 29 + int_from_byte(self._buffer[offset])
return size, offset + 1
if size == 30:
new_offset = offset + 2
size_bytes = self._buffer[offset:new_offset]
size = 285 + struct.unpack(b'!H', size_bytes)[0]
return size, new_offset
new_offset = offset + 3
size_bytes = self._buffer[offset:new_offset]
size = struct.unpack(b'!I', b'\x00' + size_bytes)[0] + 65821
return size, new_offset
|
