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DEFINITIONS
This source file includes following definitions.
- read_negTokenInit
- write_negTokenInit
- read_negTokenTarg
- write_negTokenTarg
- spnego_read_data
- spnego_write_data
- spnego_free_data
- spnego_write_mech_types
1 /*
2 Unix SMB/CIFS implementation.
3
4 RFC2478 Compliant SPNEGO implementation
5
6 Copyright (C) Jim McDonough <jmcd@us.ibm.com> 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
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 */
22
23 #include "includes.h"
24 #include "auth/gensec/spnego.h"
25 #include "auth/gensec/gensec.h"
26 #include "../lib/util/asn1.h"
27
28 static bool read_negTokenInit(struct asn1_data *asn1, TALLOC_CTX *mem_ctx,
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29 struct spnego_negTokenInit *token)
30 {
31 ZERO_STRUCTP(token);
32
33 asn1_start_tag(asn1, ASN1_CONTEXT(0));
34 asn1_start_tag(asn1, ASN1_SEQUENCE(0));
35
36 while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
37 int i;
38 uint8_t context;
39 if (!asn1_peek_uint8(asn1, &context)) {
40 asn1->has_error = true;
41 break;
42 }
43
44 switch (context) {
45 /* Read mechTypes */
46 case ASN1_CONTEXT(0):
47 asn1_start_tag(asn1, ASN1_CONTEXT(0));
48 asn1_start_tag(asn1, ASN1_SEQUENCE(0));
49
50 token->mechTypes = talloc(NULL, const char *);
51 for (i = 0; !asn1->has_error &&
52 0 < asn1_tag_remaining(asn1); i++) {
53 token->mechTypes = talloc_realloc(NULL,
54 token->mechTypes,
55 const char *, i+2);
56 asn1_read_OID(asn1, token->mechTypes, token->mechTypes + i);
57 }
58 token->mechTypes[i] = NULL;
59
60 asn1_end_tag(asn1);
61 asn1_end_tag(asn1);
62 break;
63 /* Read reqFlags */
64 case ASN1_CONTEXT(1):
65 asn1_start_tag(asn1, ASN1_CONTEXT(1));
66 asn1_read_Integer(asn1, &token->reqFlags);
67 token->reqFlags |= SPNEGO_REQ_FLAG;
68 asn1_end_tag(asn1);
69 break;
70 /* Read mechToken */
71 case ASN1_CONTEXT(2):
72 asn1_start_tag(asn1, ASN1_CONTEXT(2));
73 asn1_read_OctetString(asn1, mem_ctx, &token->mechToken);
74 asn1_end_tag(asn1);
75 break;
76 /* Read mecListMIC */
77 case ASN1_CONTEXT(3):
78 {
79 uint8_t type_peek;
80 asn1_start_tag(asn1, ASN1_CONTEXT(3));
81 if (!asn1_peek_uint8(asn1, &type_peek)) {
82 asn1->has_error = true;
83 break;
84 }
85 if (type_peek == ASN1_OCTET_STRING) {
86 asn1_read_OctetString(asn1, mem_ctx,
87 &token->mechListMIC);
88 } else {
89 /* RFC 2478 says we have an Octet String here,
90 but W2k sends something different... */
91 char *mechListMIC;
92 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
93 asn1_push_tag(asn1, ASN1_CONTEXT(0));
94 asn1_read_GeneralString(asn1, mem_ctx, &mechListMIC);
95 asn1_pop_tag(asn1);
96 asn1_pop_tag(asn1);
97
98 token->targetPrincipal = mechListMIC;
99 }
100 asn1_end_tag(asn1);
101 break;
102 }
103 default:
104 asn1->has_error = true;
105 break;
106 }
107 }
108
109 asn1_end_tag(asn1);
110 asn1_end_tag(asn1);
111
112 return !asn1->has_error;
113 }
114
115 static bool write_negTokenInit(struct asn1_data *asn1, struct spnego_negTokenInit *token)
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116 {
117 asn1_push_tag(asn1, ASN1_CONTEXT(0));
118 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
119
120 /* Write mechTypes */
121 if (token->mechTypes && *token->mechTypes) {
122 int i;
123
124 asn1_push_tag(asn1, ASN1_CONTEXT(0));
125 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
126 for (i = 0; token->mechTypes[i]; i++) {
127 asn1_write_OID(asn1, token->mechTypes[i]);
128 }
129 asn1_pop_tag(asn1);
130 asn1_pop_tag(asn1);
131 }
132
133 /* write reqFlags */
134 if (token->reqFlags & SPNEGO_REQ_FLAG) {
135 int flags = token->reqFlags & ~SPNEGO_REQ_FLAG;
136
137 asn1_push_tag(asn1, ASN1_CONTEXT(1));
138 asn1_write_Integer(asn1, flags);
139 asn1_pop_tag(asn1);
140 }
141
142 /* write mechToken */
143 if (token->mechToken.data) {
144 asn1_push_tag(asn1, ASN1_CONTEXT(2));
145 asn1_write_OctetString(asn1, token->mechToken.data,
146 token->mechToken.length);
147 asn1_pop_tag(asn1);
148 }
149
150 /* write mechListMIC */
151 if (token->mechListMIC.data) {
152 asn1_push_tag(asn1, ASN1_CONTEXT(3));
153 #if 0
154 /* This is what RFC 2478 says ... */
155 asn1_write_OctetString(asn1, token->mechListMIC.data,
156 token->mechListMIC.length);
157 #else
158 /* ... but unfortunately this is what Windows
159 sends/expects */
160 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
161 asn1_push_tag(asn1, ASN1_CONTEXT(0));
162 asn1_push_tag(asn1, ASN1_GENERAL_STRING);
163 asn1_write(asn1, token->mechListMIC.data,
164 token->mechListMIC.length);
165 asn1_pop_tag(asn1);
166 asn1_pop_tag(asn1);
167 asn1_pop_tag(asn1);
168 #endif
169 asn1_pop_tag(asn1);
170 }
171
172 asn1_pop_tag(asn1);
173 asn1_pop_tag(asn1);
174
175 return !asn1->has_error;
176 }
177
178 static bool read_negTokenTarg(struct asn1_data *asn1, TALLOC_CTX *mem_ctx,
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179 struct spnego_negTokenTarg *token)
180 {
181 ZERO_STRUCTP(token);
182
183 asn1_start_tag(asn1, ASN1_CONTEXT(1));
184 asn1_start_tag(asn1, ASN1_SEQUENCE(0));
185
186 while (!asn1->has_error && 0 < asn1_tag_remaining(asn1)) {
187 uint8_t context;
188 if (!asn1_peek_uint8(asn1, &context)) {
189 asn1->has_error = true;
190 break;
191 }
192
193 switch (context) {
194 case ASN1_CONTEXT(0):
195 asn1_start_tag(asn1, ASN1_CONTEXT(0));
196 asn1_start_tag(asn1, ASN1_ENUMERATED);
197 asn1_read_uint8(asn1, &token->negResult);
198 asn1_end_tag(asn1);
199 asn1_end_tag(asn1);
200 break;
201 case ASN1_CONTEXT(1):
202 asn1_start_tag(asn1, ASN1_CONTEXT(1));
203 asn1_read_OID(asn1, mem_ctx, &token->supportedMech);
204 asn1_end_tag(asn1);
205 break;
206 case ASN1_CONTEXT(2):
207 asn1_start_tag(asn1, ASN1_CONTEXT(2));
208 asn1_read_OctetString(asn1, mem_ctx, &token->responseToken);
209 asn1_end_tag(asn1);
210 break;
211 case ASN1_CONTEXT(3):
212 asn1_start_tag(asn1, ASN1_CONTEXT(3));
213 asn1_read_OctetString(asn1, mem_ctx, &token->mechListMIC);
214 asn1_end_tag(asn1);
215 break;
216 default:
217 asn1->has_error = true;
218 break;
219 }
220 }
221
222 asn1_end_tag(asn1);
223 asn1_end_tag(asn1);
224
225 return !asn1->has_error;
226 }
227
228 static bool write_negTokenTarg(struct asn1_data *asn1, struct spnego_negTokenTarg *token)
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229 {
230 asn1_push_tag(asn1, ASN1_CONTEXT(1));
231 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
232
233 if (token->negResult != SPNEGO_NONE_RESULT) {
234 asn1_push_tag(asn1, ASN1_CONTEXT(0));
235 asn1_write_enumerated(asn1, token->negResult);
236 asn1_pop_tag(asn1);
237 }
238
239 if (token->supportedMech) {
240 asn1_push_tag(asn1, ASN1_CONTEXT(1));
241 asn1_write_OID(asn1, token->supportedMech);
242 asn1_pop_tag(asn1);
243 }
244
245 if (token->responseToken.data) {
246 asn1_push_tag(asn1, ASN1_CONTEXT(2));
247 asn1_write_OctetString(asn1, token->responseToken.data,
248 token->responseToken.length);
249 asn1_pop_tag(asn1);
250 }
251
252 if (token->mechListMIC.data) {
253 asn1_push_tag(asn1, ASN1_CONTEXT(3));
254 asn1_write_OctetString(asn1, token->mechListMIC.data,
255 token->mechListMIC.length);
256 asn1_pop_tag(asn1);
257 }
258
259 asn1_pop_tag(asn1);
260 asn1_pop_tag(asn1);
261
262 return !asn1->has_error;
263 }
264
265 ssize_t spnego_read_data(TALLOC_CTX *mem_ctx, DATA_BLOB data, struct spnego_data *token)
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266 {
267 struct asn1_data *asn1;
268 ssize_t ret = -1;
269 uint8_t context;
270
271 ZERO_STRUCTP(token);
272
273 if (data.length == 0) {
274 return ret;
275 }
276
277 asn1 = asn1_init(mem_ctx);
278 if (asn1 == NULL) {
279 return -1;
280 }
281
282 asn1_load(asn1, data);
283
284 if (!asn1_peek_uint8(asn1, &context)) {
285 asn1->has_error = true;
286 } else {
287 switch (context) {
288 case ASN1_APPLICATION(0):
289 asn1_start_tag(asn1, ASN1_APPLICATION(0));
290 asn1_check_OID(asn1, GENSEC_OID_SPNEGO);
291 if (read_negTokenInit(asn1, mem_ctx, &token->negTokenInit)) {
292 token->type = SPNEGO_NEG_TOKEN_INIT;
293 }
294 asn1_end_tag(asn1);
295 break;
296 case ASN1_CONTEXT(1):
297 if (read_negTokenTarg(asn1, mem_ctx, &token->negTokenTarg)) {
298 token->type = SPNEGO_NEG_TOKEN_TARG;
299 }
300 break;
301 default:
302 asn1->has_error = true;
303 break;
304 }
305 }
306
307 if (!asn1->has_error) ret = asn1->ofs;
308 asn1_free(asn1);
309
310 return ret;
311 }
312
313 ssize_t spnego_write_data(TALLOC_CTX *mem_ctx, DATA_BLOB *blob, struct spnego_data *spnego)
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314 {
315 struct asn1_data *asn1 = asn1_init(mem_ctx);
316 ssize_t ret = -1;
317
318 if (asn1 == NULL) {
319 return -1;
320 }
321
322 switch (spnego->type) {
323 case SPNEGO_NEG_TOKEN_INIT:
324 asn1_push_tag(asn1, ASN1_APPLICATION(0));
325 asn1_write_OID(asn1, GENSEC_OID_SPNEGO);
326 write_negTokenInit(asn1, &spnego->negTokenInit);
327 asn1_pop_tag(asn1);
328 break;
329 case SPNEGO_NEG_TOKEN_TARG:
330 write_negTokenTarg(asn1, &spnego->negTokenTarg);
331 break;
332 default:
333 asn1->has_error = true;
334 break;
335 }
336
337 if (!asn1->has_error) {
338 *blob = data_blob_talloc(mem_ctx, asn1->data, asn1->length);
339 ret = asn1->ofs;
340 }
341 asn1_free(asn1);
342
343 return ret;
344 }
345
346 bool spnego_free_data(struct spnego_data *spnego)
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347 {
348 bool ret = true;
349
350 if (!spnego) goto out;
351
352 switch(spnego->type) {
353 case SPNEGO_NEG_TOKEN_INIT:
354 if (spnego->negTokenInit.mechTypes) {
355 talloc_free(spnego->negTokenInit.mechTypes);
356 }
357 data_blob_free(&spnego->negTokenInit.mechToken);
358 data_blob_free(&spnego->negTokenInit.mechListMIC);
359 talloc_free(spnego->negTokenInit.targetPrincipal);
360 break;
361 case SPNEGO_NEG_TOKEN_TARG:
362 if (spnego->negTokenTarg.supportedMech) {
363 talloc_free(discard_const(spnego->negTokenTarg.supportedMech));
364 }
365 data_blob_free(&spnego->negTokenTarg.responseToken);
366 data_blob_free(&spnego->negTokenTarg.mechListMIC);
367 break;
368 default:
369 ret = false;
370 break;
371 }
372 ZERO_STRUCTP(spnego);
373 out:
374 return ret;
375 }
376
377 bool spnego_write_mech_types(TALLOC_CTX *mem_ctx,
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378 const char **mech_types,
379 DATA_BLOB *blob)
380 {
381 struct asn1_data *asn1 = asn1_init(mem_ctx);
382
383 /* Write mechTypes */
384 if (mech_types && *mech_types) {
385 int i;
386
387 asn1_push_tag(asn1, ASN1_SEQUENCE(0));
388 for (i = 0; mech_types[i]; i++) {
389 asn1_write_OID(asn1, mech_types[i]);
390 }
391 asn1_pop_tag(asn1);
392 }
393
394 if (asn1->has_error) {
395 asn1_free(asn1);
396 return false;
397 }
398
399 *blob = data_blob_talloc(mem_ctx, asn1->data, asn1->length);
400 if (blob->length != asn1->length) {
401 asn1_free(asn1);
402 return false;
403 }
404
405 asn1_free(asn1);
406
407 return true;
408 }