source: trunk/server/libcli/auth/msrpc_parse.c

Last change on this file was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 10.1 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 simple kerberos5/SPNEGO routines
4 Copyright (C) Andrew Tridgell 2001
5 Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2002
6 Copyright (C) Andrew Bartlett 2002-2003
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
20*/
21
22#include "includes.h"
23#include "libcli/auth/msrpc_parse.h"
24
25/*
26 this is a tiny msrpc packet generator. I am only using this to
27 avoid tying this code to a particular varient of our rpc code. This
28 generator is not general enough for all our rpc needs, its just
29 enough for the spnego/ntlmssp code
30
31 format specifiers are:
32
33 U = unicode string (input is unix string)
34 a = address (input is char *unix_string)
35 (1 byte type, 1 byte length, unicode/ASCII string, all inline)
36 A = ASCII string (input is unix string)
37 B = data blob (pointer + length)
38 b = data blob in header (pointer + length)
39 D
40 d = word (4 bytes)
41 C = constant ascii string
42 */
43NTSTATUS msrpc_gen(TALLOC_CTX *mem_ctx,
44 DATA_BLOB *blob,
45 const char *format, ...)
46{
47 int i, j;
48 bool ret;
49 va_list ap;
50 char *s;
51 uint8_t *b;
52 int head_size=0, data_size=0;
53 int head_ofs, data_ofs;
54 int *intargs;
55 size_t n;
56
57 DATA_BLOB *pointers;
58
59 pointers = talloc_array(mem_ctx, DATA_BLOB, strlen(format));
60 if (!pointers) {
61 return NT_STATUS_NO_MEMORY;
62 }
63 intargs = talloc_array(pointers, int, strlen(format));
64 if (!intargs) {
65 return NT_STATUS_NO_MEMORY;
66 }
67
68 /* first scan the format to work out the header and body size */
69 va_start(ap, format);
70 for (i=0; format[i]; i++) {
71 switch (format[i]) {
72 case 'U':
73 s = va_arg(ap, char *);
74 head_size += 8;
75 ret = push_ucs2_talloc(
76 pointers,
77 (smb_ucs2_t **)(void *)&pointers[i].data,
78 s, &n);
79 if (!ret) {
80 va_end(ap);
81 return map_nt_error_from_unix(errno);
82 }
83 pointers[i].length = n;
84 pointers[i].length -= 2;
85 data_size += pointers[i].length;
86 break;
87 case 'A':
88 s = va_arg(ap, char *);
89 head_size += 8;
90 ret = push_ascii_talloc(
91 pointers, (char **)(void *)&pointers[i].data,
92 s, &n);
93 if (!ret) {
94 va_end(ap);
95 return map_nt_error_from_unix(errno);
96 }
97 pointers[i].length = n;
98 pointers[i].length -= 1;
99 data_size += pointers[i].length;
100 break;
101 case 'a':
102 j = va_arg(ap, int);
103 intargs[i] = j;
104 s = va_arg(ap, char *);
105 ret = push_ucs2_talloc(
106 pointers,
107 (smb_ucs2_t **)(void *)&pointers[i].data,
108 s, &n);
109 if (!ret) {
110 va_end(ap);
111 return map_nt_error_from_unix(errno);
112 }
113 pointers[i].length = n;
114 pointers[i].length -= 2;
115 data_size += pointers[i].length + 4;
116 break;
117 case 'B':
118 b = va_arg(ap, uint8_t *);
119 head_size += 8;
120 pointers[i].data = b;
121 pointers[i].length = va_arg(ap, int);
122 data_size += pointers[i].length;
123 break;
124 case 'b':
125 b = va_arg(ap, uint8_t *);
126 pointers[i].data = b;
127 pointers[i].length = va_arg(ap, int);
128 head_size += pointers[i].length;
129 break;
130 case 'd':
131 j = va_arg(ap, int);
132 intargs[i] = j;
133 head_size += 4;
134 break;
135 case 'C':
136 s = va_arg(ap, char *);
137 pointers[i].data = (uint8_t *)s;
138 pointers[i].length = strlen(s)+1;
139 head_size += pointers[i].length;
140 break;
141 default:
142 va_end(ap);
143 return NT_STATUS_INVALID_PARAMETER;
144 }
145 }
146 va_end(ap);
147
148 if (head_size + data_size == 0) {
149 return NT_STATUS_INVALID_PARAMETER;
150 }
151
152 /* allocate the space, then scan the format again to fill in the values */
153 *blob = data_blob_talloc(mem_ctx, NULL, head_size + data_size);
154 if (!blob->data) {
155 return NT_STATUS_NO_MEMORY;
156 }
157 head_ofs = 0;
158 data_ofs = head_size;
159
160 va_start(ap, format);
161 for (i=0; format[i]; i++) {
162 switch (format[i]) {
163 case 'U':
164 case 'A':
165 case 'B':
166 n = pointers[i].length;
167 SSVAL(blob->data, head_ofs, n); head_ofs += 2;
168 SSVAL(blob->data, head_ofs, n); head_ofs += 2;
169 SIVAL(blob->data, head_ofs, data_ofs); head_ofs += 4;
170 if (pointers[i].data && n) /* don't follow null pointers... */
171 memcpy(blob->data+data_ofs, pointers[i].data, n);
172 data_ofs += n;
173 break;
174 case 'a':
175 j = intargs[i];
176 SSVAL(blob->data, data_ofs, j); data_ofs += 2;
177
178 n = pointers[i].length;
179 SSVAL(blob->data, data_ofs, n); data_ofs += 2;
180 if (n >= 0) {
181 memcpy(blob->data+data_ofs, pointers[i].data, n);
182 }
183 data_ofs += n;
184 break;
185 case 'd':
186 j = intargs[i];
187 SIVAL(blob->data, head_ofs, j);
188 head_ofs += 4;
189 break;
190 case 'b':
191 n = pointers[i].length;
192 if (pointers[i].data && n) {
193 /* don't follow null pointers... */
194 memcpy(blob->data + head_ofs, pointers[i].data, n);
195 }
196 head_ofs += n;
197 break;
198 case 'C':
199 n = pointers[i].length;
200 memcpy(blob->data + head_ofs, pointers[i].data, n);
201 head_ofs += n;
202 break;
203 default:
204 va_end(ap);
205 return NT_STATUS_INVALID_PARAMETER;
206 }
207 }
208 va_end(ap);
209
210 talloc_free(pointers);
211
212 return NT_STATUS_OK;
213}
214
215
216/* a helpful macro to avoid running over the end of our blob */
217#define NEED_DATA(amount) \
218if ((head_ofs + amount) > blob->length) { \
219 va_end(ap); \
220 return false; \
221}
222
223/**
224 this is a tiny msrpc packet parser. This the the partner of msrpc_gen
225
226 format specifiers are:
227
228 U = unicode string (output is unix string)
229 A = ascii string
230 B = data blob
231 b = data blob in header
232 d = word (4 bytes)
233 C = constant ascii string
234 */
235
236bool msrpc_parse(TALLOC_CTX *mem_ctx,
237 const DATA_BLOB *blob,
238 const char *format, ...)
239{
240 int i;
241 va_list ap;
242 char **ps, *s;
243 DATA_BLOB *b;
244 size_t head_ofs = 0;
245 uint16_t len1, len2;
246 uint32_t ptr;
247 uint32_t *v;
248 size_t p_len = 1024;
249 char *p = talloc_array(mem_ctx, char, p_len);
250 bool ret = true;
251
252 if (!p) {
253 return false;
254 }
255
256 va_start(ap, format);
257 for (i=0; format[i]; i++) {
258 switch (format[i]) {
259 case 'U':
260 NEED_DATA(8);
261 len1 = SVAL(blob->data, head_ofs); head_ofs += 2;
262 len2 = SVAL(blob->data, head_ofs); head_ofs += 2;
263 ptr = IVAL(blob->data, head_ofs); head_ofs += 4;
264
265 ps = va_arg(ap, char **);
266 if (len1 == 0 && len2 == 0) {
267 *ps = (char *)discard_const("");
268 } else {
269 /* make sure its in the right format - be strict */
270 if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
271 ret = false;
272 goto cleanup;
273 }
274 if (len1 & 1) {
275 /* if odd length and unicode */
276 ret = false;
277 goto cleanup;
278 }
279 if (blob->data + ptr < (uint8_t *)(uintptr_t)ptr ||
280 blob->data + ptr < blob->data) {
281 ret = false;
282 goto cleanup;
283 }
284
285 if (0 < len1) {
286 size_t pull_len;
287 if (!convert_string_talloc(mem_ctx, CH_UTF16, CH_UNIX,
288 blob->data + ptr, len1,
289 ps, &pull_len, false)) {
290 ret = false;
291 goto cleanup;
292 }
293 } else {
294 (*ps) = (char *)discard_const("");
295 }
296 }
297 break;
298 case 'A':
299 NEED_DATA(8);
300 len1 = SVAL(blob->data, head_ofs); head_ofs += 2;
301 len2 = SVAL(blob->data, head_ofs); head_ofs += 2;
302 ptr = IVAL(blob->data, head_ofs); head_ofs += 4;
303
304 ps = (char **)va_arg(ap, char **);
305 /* make sure its in the right format - be strict */
306 if (len1 == 0 && len2 == 0) {
307 *ps = (char *)discard_const("");
308 } else {
309 if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
310 ret = false;
311 goto cleanup;
312 }
313
314 if (blob->data + ptr < (uint8_t *)(uintptr_t)ptr ||
315 blob->data + ptr < blob->data) {
316 ret = false;
317 goto cleanup;
318 }
319
320 if (0 < len1) {
321 size_t pull_len;
322
323 if (!convert_string_talloc(mem_ctx, CH_DOS, CH_UNIX,
324 blob->data + ptr, len1,
325 ps, &pull_len, false)) {
326 ret = false;
327 goto cleanup;
328 }
329 } else {
330 (*ps) = (char *)discard_const("");
331 }
332 }
333 break;
334 case 'B':
335 NEED_DATA(8);
336 len1 = SVAL(blob->data, head_ofs); head_ofs += 2;
337 len2 = SVAL(blob->data, head_ofs); head_ofs += 2;
338 ptr = IVAL(blob->data, head_ofs); head_ofs += 4;
339
340 b = (DATA_BLOB *)va_arg(ap, void *);
341 if (len1 == 0 && len2 == 0) {
342 *b = data_blob_talloc(mem_ctx, NULL, 0);
343 } else {
344 /* make sure its in the right format - be strict */
345 if ((len1 != len2) || (ptr + len1 < ptr) || (ptr + len1 < len1) || (ptr + len1 > blob->length)) {
346 ret = false;
347 goto cleanup;
348 }
349
350 if (blob->data + ptr < (uint8_t *)(uintptr_t)ptr ||
351 blob->data + ptr < blob->data) {
352 ret = false;
353 goto cleanup;
354 }
355
356 *b = data_blob_talloc(mem_ctx, blob->data + ptr, len1);
357 }
358 break;
359 case 'b':
360 b = (DATA_BLOB *)va_arg(ap, void *);
361 len1 = va_arg(ap, unsigned int);
362 /* make sure its in the right format - be strict */
363 NEED_DATA(len1);
364 if (blob->data + head_ofs < (uint8_t *)head_ofs ||
365 blob->data + head_ofs < blob->data) {
366 ret = false;
367 goto cleanup;
368 }
369
370 *b = data_blob_talloc(mem_ctx, blob->data + head_ofs, len1);
371 head_ofs += len1;
372 break;
373 case 'd':
374 v = va_arg(ap, uint32_t *);
375 NEED_DATA(4);
376 *v = IVAL(blob->data, head_ofs); head_ofs += 4;
377 break;
378 case 'C':
379 s = va_arg(ap, char *);
380
381 if (blob->data + head_ofs < (uint8_t *)head_ofs ||
382 blob->data + head_ofs < blob->data ||
383 (head_ofs + (strlen(s) + 1)) > blob->length) {
384 ret = false;
385 goto cleanup;
386 }
387
388 if (memcmp(blob->data + head_ofs, s, strlen(s)+1) != 0) {
389 ret = false;
390 goto cleanup;
391 }
392 head_ofs += (strlen(s) + 1);
393
394 break;
395 }
396 }
397
398cleanup:
399 va_end(ap);
400 talloc_free(p);
401 return ret;
402}
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