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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
/*
Unix SMB/CIFS implementation.
SMB2 Create Context Blob handling
Copyright (C) Andrew Tridgell 2005
Copyright (C) Stefan Metzmacher 2008-2009
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "../libcli/smb/smb_common.h"
static size_t smb2_create_blob_padding(uint32_t offset, size_t n)
{
if ((offset & (n-1)) == 0) return 0;
return n - (offset & (n-1));
}
/*
parse a set of SMB2 create blobs
*/
NTSTATUS smb2_create_blob_parse(TALLOC_CTX *mem_ctx, const DATA_BLOB buffer,
struct smb2_create_blobs *blobs)
{
const uint8_t *data = buffer.data;
uint32_t remaining = buffer.length;
while (remaining > 0) {
uint32_t next;
uint32_t name_offset, name_length;
uint32_t data_offset;
uint32_t data_length;
char *tag;
DATA_BLOB b;
NTSTATUS status;
if (remaining < 16) {
return NT_STATUS_INVALID_PARAMETER;
}
next = IVAL(data, 0);
name_offset = SVAL(data, 4);
name_length = SVAL(data, 6);
#if 0
reserved = SVAL(data, 8);
#endif
data_offset = SVAL(data, 10);
data_length = IVAL(data, 12);
if ((next & 0x7) != 0 ||
next > remaining ||
name_offset != 16 ||
name_length < 4 ||
name_offset + name_length > remaining ||
(data_offset & 0x7) != 0 ||
(data_offset && (data_offset < name_offset + name_length)) ||
(data_offset && (data_offset > remaining)) ||
(data_offset && data_length &&
(data_offset + (uint64_t)data_length > remaining))) {
return NT_STATUS_INVALID_PARAMETER;
}
tag = talloc_strndup(mem_ctx, (const char *)data + name_offset, name_length);
if (tag == NULL) {
return NT_STATUS_NO_MEMORY;
}
b = data_blob_const(data+data_offset, data_length);
status = smb2_create_blob_add(mem_ctx, blobs, tag, b);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
talloc_free(tag);
if (next == 0) break;
remaining -= next;
data += next;
if (remaining < 16) {
return NT_STATUS_INVALID_PARAMETER;
}
}
return NT_STATUS_OK;
}
/*
add a blob to a smb2_create attribute blob
*/
static NTSTATUS smb2_create_blob_push_one(TALLOC_CTX *mem_ctx, DATA_BLOB *buffer,
const struct smb2_create_blob *blob,
bool last)
{
uint32_t ofs = buffer->length;
size_t tag_length = strlen(blob->tag);
size_t blob_offset = 0;
size_t blob_pad = 0;
size_t next_offset = 0;
size_t next_pad = 0;
bool ok;
blob_offset = 0x14 + tag_length;
blob_pad = smb2_create_blob_padding(blob_offset, 8);
next_offset = blob_offset + blob_pad + blob->data.length;
if (!last) {
next_pad = smb2_create_blob_padding(next_offset, 8);
}
ok = data_blob_realloc(mem_ctx, buffer,
buffer->length + next_offset + next_pad);
if (!ok) {
return NT_STATUS_NO_MEMORY;
}
if (last) {
SIVAL(buffer->data, ofs+0x00, 0);
} else {
SIVAL(buffer->data, ofs+0x00, next_offset + next_pad);
}
SSVAL(buffer->data, ofs+0x04, 0x10); /* offset of tag */
SIVAL(buffer->data, ofs+0x06, tag_length); /* tag length */
SSVAL(buffer->data, ofs+0x0A, blob_offset + blob_pad); /* offset of data */
SIVAL(buffer->data, ofs+0x0C, blob->data.length);
memcpy(buffer->data+ofs+0x10, blob->tag, tag_length);
if (blob_pad > 0) {
memset(buffer->data+ofs+blob_offset, 0, blob_pad);
blob_offset += blob_pad;
}
memcpy(buffer->data+ofs+blob_offset, blob->data.data, blob->data.length);
if (next_pad > 0) {
memset(buffer->data+ofs+next_offset, 0, next_pad);
next_offset += next_pad;
}
return NT_STATUS_OK;
}
/*
create a buffer of a set of create blobs
*/
NTSTATUS smb2_create_blob_push(TALLOC_CTX *mem_ctx, DATA_BLOB *buffer,
const struct smb2_create_blobs blobs)
{
int i;
NTSTATUS status;
*buffer = data_blob(NULL, 0);
for (i=0; i < blobs.num_blobs; i++) {
bool last = false;
const struct smb2_create_blob *c;
if ((i + 1) == blobs.num_blobs) {
last = true;
}
c = &blobs.blobs[i];
status = smb2_create_blob_push_one(mem_ctx, buffer, c, last);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
}
return NT_STATUS_OK;
}
NTSTATUS smb2_create_blob_add(TALLOC_CTX *mem_ctx, struct smb2_create_blobs *b,
const char *tag, DATA_BLOB data)
{
struct smb2_create_blob *array;
array = talloc_realloc(mem_ctx, b->blobs,
struct smb2_create_blob,
b->num_blobs + 1);
NT_STATUS_HAVE_NO_MEMORY(array);
b->blobs = array;
b->blobs[b->num_blobs].tag = talloc_strdup(b->blobs, tag);
NT_STATUS_HAVE_NO_MEMORY(b->blobs[b->num_blobs].tag);
if (data.data) {
b->blobs[b->num_blobs].data = data_blob_talloc(b->blobs,
data.data,
data.length);
NT_STATUS_HAVE_NO_MEMORY(b->blobs[b->num_blobs].data.data);
} else {
b->blobs[b->num_blobs].data = data_blob_null;
}
b->num_blobs += 1;
return NT_STATUS_OK;
}
/*
* return the first blob with the given tag
*/
struct smb2_create_blob *smb2_create_blob_find(const struct smb2_create_blobs *b,
const char *tag)
{
uint32_t i;
for (i=0; i < b->num_blobs; i++) {
if (strcmp(b->blobs[i].tag, tag) == 0) {
return &b->blobs[i];
}
}
return NULL;
}
|
