tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * The ASB.1/BER parsing code is derived from ip_nat_snmp_basic.c which was in
3 * turn derived from the gxsnmp package by Gregory McLean & Jochen Friedrich
4 *
5 * Copyright (c) 2000 RP Internet (www.rpi.net.au).
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/config.h>
21#include <linux/module.h>
22#include <linux/types.h>
23#include <linux/kernel.h>
24#include <linux/mm.h>
25#include <linux/slab.h>
26#include "cifspdu.h"
27#include "cifsglob.h"
28#include "cifs_debug.h"
29#include "cifsproto.h"
30
31/*****************************************************************************
32 *
33 * Basic ASN.1 decoding routines (gxsnmp author Dirk Wisse)
34 *
35 *****************************************************************************/
36
37/* Class */
38#define ASN1_UNI 0 /* Universal */
39#define ASN1_APL 1 /* Application */
40#define ASN1_CTX 2 /* Context */
41#define ASN1_PRV 3 /* Private */
42
43/* Tag */
44#define ASN1_EOC 0 /* End Of Contents or N/A */
45#define ASN1_BOL 1 /* Boolean */
46#define ASN1_INT 2 /* Integer */
47#define ASN1_BTS 3 /* Bit String */
48#define ASN1_OTS 4 /* Octet String */
49#define ASN1_NUL 5 /* Null */
50#define ASN1_OJI 6 /* Object Identifier */
51#define ASN1_OJD 7 /* Object Description */
52#define ASN1_EXT 8 /* External */
53#define ASN1_SEQ 16 /* Sequence */
54#define ASN1_SET 17 /* Set */
55#define ASN1_NUMSTR 18 /* Numerical String */
56#define ASN1_PRNSTR 19 /* Printable String */
57#define ASN1_TEXSTR 20 /* Teletext String */
58#define ASN1_VIDSTR 21 /* Video String */
59#define ASN1_IA5STR 22 /* IA5 String */
60#define ASN1_UNITIM 23 /* Universal Time */
61#define ASN1_GENTIM 24 /* General Time */
62#define ASN1_GRASTR 25 /* Graphical String */
63#define ASN1_VISSTR 26 /* Visible String */
64#define ASN1_GENSTR 27 /* General String */
65
66/* Primitive / Constructed methods*/
67#define ASN1_PRI 0 /* Primitive */
68#define ASN1_CON 1 /* Constructed */
69
70/*
71 * Error codes.
72 */
73#define ASN1_ERR_NOERROR 0
74#define ASN1_ERR_DEC_EMPTY 2
75#define ASN1_ERR_DEC_EOC_MISMATCH 3
76#define ASN1_ERR_DEC_LENGTH_MISMATCH 4
77#define ASN1_ERR_DEC_BADVALUE 5
78
79#define SPNEGO_OID_LEN 7
80#define NTLMSSP_OID_LEN 10
81static unsigned long SPNEGO_OID[7] = { 1, 3, 6, 1, 5, 5, 2 };
82static unsigned long NTLMSSP_OID[10] = { 1, 3, 6, 1, 4, 1, 311, 2, 2, 10 };
83
84/*
85 * ASN.1 context.
86 */
87struct asn1_ctx {
88 int error; /* Error condition */
89 unsigned char *pointer; /* Octet just to be decoded */
90 unsigned char *begin; /* First octet */
91 unsigned char *end; /* Octet after last octet */
92};
93
94/*
95 * Octet string (not null terminated)
96 */
97struct asn1_octstr {
98 unsigned char *data;
99 unsigned int len;
100};
101
102static void
103asn1_open(struct asn1_ctx *ctx, unsigned char *buf, unsigned int len)
104{
105 ctx->begin = buf;
106 ctx->end = buf + len;
107 ctx->pointer = buf;
108 ctx->error = ASN1_ERR_NOERROR;
109}
110
111static unsigned char
112asn1_octet_decode(struct asn1_ctx *ctx, unsigned char *ch)
113{
114 if (ctx->pointer >= ctx->end) {
115 ctx->error = ASN1_ERR_DEC_EMPTY;
116 return 0;
117 }
118 *ch = *(ctx->pointer)++;
119 return 1;
120}
121
122static unsigned char
123asn1_tag_decode(struct asn1_ctx *ctx, unsigned int *tag)
124{
125 unsigned char ch;
126
127 *tag = 0;
128
129 do {
130 if (!asn1_octet_decode(ctx, &ch))
131 return 0;
132 *tag <<= 7;
133 *tag |= ch & 0x7F;
134 } while ((ch & 0x80) == 0x80);
135 return 1;
136}
137
138static unsigned char
139asn1_id_decode(struct asn1_ctx *ctx,
140 unsigned int *cls, unsigned int *con, unsigned int *tag)
141{
142 unsigned char ch;
143
144 if (!asn1_octet_decode(ctx, &ch))
145 return 0;
146
147 *cls = (ch & 0xC0) >> 6;
148 *con = (ch & 0x20) >> 5;
149 *tag = (ch & 0x1F);
150
151 if (*tag == 0x1F) {
152 if (!asn1_tag_decode(ctx, tag))
153 return 0;
154 }
155 return 1;
156}
157
158static unsigned char
159asn1_length_decode(struct asn1_ctx *ctx, unsigned int *def, unsigned int *len)
160{
161 unsigned char ch, cnt;
162
163 if (!asn1_octet_decode(ctx, &ch))
164 return 0;
165
166 if (ch == 0x80)
167 *def = 0;
168 else {
169 *def = 1;
170
171 if (ch < 0x80)
172 *len = ch;
173 else {
174 cnt = (unsigned char) (ch & 0x7F);
175 *len = 0;
176
177 while (cnt > 0) {
178 if (!asn1_octet_decode(ctx, &ch))
179 return 0;
180 *len <<= 8;
181 *len |= ch;
182 cnt--;
183 }
184 }
185 }
186 return 1;
187}
188
189static unsigned char
190asn1_header_decode(struct asn1_ctx *ctx,
191 unsigned char **eoc,
192 unsigned int *cls, unsigned int *con, unsigned int *tag)
193{
194 unsigned int def, len;
195
196 if (!asn1_id_decode(ctx, cls, con, tag))
197 return 0;
198
199 if (!asn1_length_decode(ctx, &def, &len))
200 return 0;
201
202 if (def)
203 *eoc = ctx->pointer + len;
204 else
205 *eoc = NULL;
206 return 1;
207}
208
209static unsigned char
210asn1_eoc_decode(struct asn1_ctx *ctx, unsigned char *eoc)
211{
212 unsigned char ch;
213
214 if (eoc == NULL) {
215 if (!asn1_octet_decode(ctx, &ch))
216 return 0;
217
218 if (ch != 0x00) {
219 ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
220 return 0;
221 }
222
223 if (!asn1_octet_decode(ctx, &ch))
224 return 0;
225
226 if (ch != 0x00) {
227 ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
228 return 0;
229 }
230 return 1;
231 } else {
232 if (ctx->pointer != eoc) {
233 ctx->error = ASN1_ERR_DEC_LENGTH_MISMATCH;
234 return 0;
235 }
236 return 1;
237 }
238}
239
240/* static unsigned char asn1_null_decode(struct asn1_ctx *ctx,
241 unsigned char *eoc)
242{
243 ctx->pointer = eoc;
244 return 1;
245}
246
247static unsigned char asn1_long_decode(struct asn1_ctx *ctx,
248 unsigned char *eoc, long *integer)
249{
250 unsigned char ch;
251 unsigned int len;
252
253 if (!asn1_octet_decode(ctx, &ch))
254 return 0;
255
256 *integer = (signed char) ch;
257 len = 1;
258
259 while (ctx->pointer < eoc) {
260 if (++len > sizeof(long)) {
261 ctx->error = ASN1_ERR_DEC_BADVALUE;
262 return 0;
263 }
264
265 if (!asn1_octet_decode(ctx, &ch))
266 return 0;
267
268 *integer <<= 8;
269 *integer |= ch;
270 }
271 return 1;
272}
273
274static unsigned char asn1_uint_decode(struct asn1_ctx *ctx,
275 unsigned char *eoc,
276 unsigned int *integer)
277{
278 unsigned char ch;
279 unsigned int len;
280
281 if (!asn1_octet_decode(ctx, &ch))
282 return 0;
283
284 *integer = ch;
285 if (ch == 0)
286 len = 0;
287 else
288 len = 1;
289
290 while (ctx->pointer < eoc) {
291 if (++len > sizeof(unsigned int)) {
292 ctx->error = ASN1_ERR_DEC_BADVALUE;
293 return 0;
294 }
295
296 if (!asn1_octet_decode(ctx, &ch))
297 return 0;
298
299 *integer <<= 8;
300 *integer |= ch;
301 }
302 return 1;
303}
304
305static unsigned char asn1_ulong_decode(struct asn1_ctx *ctx,
306 unsigned char *eoc,
307 unsigned long *integer)
308{
309 unsigned char ch;
310 unsigned int len;
311
312 if (!asn1_octet_decode(ctx, &ch))
313 return 0;
314
315 *integer = ch;
316 if (ch == 0)
317 len = 0;
318 else
319 len = 1;
320
321 while (ctx->pointer < eoc) {
322 if (++len > sizeof(unsigned long)) {
323 ctx->error = ASN1_ERR_DEC_BADVALUE;
324 return 0;
325 }
326
327 if (!asn1_octet_decode(ctx, &ch))
328 return 0;
329
330 *integer <<= 8;
331 *integer |= ch;
332 }
333 return 1;
334}
335
336static unsigned char
337asn1_octets_decode(struct asn1_ctx *ctx,
338 unsigned char *eoc,
339 unsigned char **octets, unsigned int *len)
340{
341 unsigned char *ptr;
342
343 *len = 0;
344
345 *octets = kmalloc(eoc - ctx->pointer, GFP_ATOMIC);
346 if (*octets == NULL) {
347 return 0;
348 }
349
350 ptr = *octets;
351 while (ctx->pointer < eoc) {
352 if (!asn1_octet_decode(ctx, (unsigned char *) ptr++)) {
353 kfree(*octets);
354 *octets = NULL;
355 return 0;
356 }
357 (*len)++;
358 }
359 return 1;
360} */
361
362static unsigned char
363asn1_subid_decode(struct asn1_ctx *ctx, unsigned long *subid)
364{
365 unsigned char ch;
366
367 *subid = 0;
368
369 do {
370 if (!asn1_octet_decode(ctx, &ch))
371 return 0;
372
373 *subid <<= 7;
374 *subid |= ch & 0x7F;
375 } while ((ch & 0x80) == 0x80);
376 return 1;
377}
378
379static int
380asn1_oid_decode(struct asn1_ctx *ctx,
381 unsigned char *eoc, unsigned long **oid, unsigned int *len)
382{
383 unsigned long subid;
384 unsigned int size;
385 unsigned long *optr;
386
387 size = eoc - ctx->pointer + 1;
388 *oid = kmalloc(size * sizeof (unsigned long), GFP_ATOMIC);
389 if (*oid == NULL) {
390 return 0;
391 }
392
393 optr = *oid;
394
395 if (!asn1_subid_decode(ctx, &subid)) {
396 kfree(*oid);
397 *oid = NULL;
398 return 0;
399 }
400
401 if (subid < 40) {
402 optr[0] = 0;
403 optr[1] = subid;
404 } else if (subid < 80) {
405 optr[0] = 1;
406 optr[1] = subid - 40;
407 } else {
408 optr[0] = 2;
409 optr[1] = subid - 80;
410 }
411
412 *len = 2;
413 optr += 2;
414
415 while (ctx->pointer < eoc) {
416 if (++(*len) > size) {
417 ctx->error = ASN1_ERR_DEC_BADVALUE;
418 kfree(*oid);
419 *oid = NULL;
420 return 0;
421 }
422
423 if (!asn1_subid_decode(ctx, optr++)) {
424 kfree(*oid);
425 *oid = NULL;
426 return 0;
427 }
428 }
429 return 1;
430}
431
432static int
433compare_oid(unsigned long *oid1, unsigned int oid1len,
434 unsigned long *oid2, unsigned int oid2len)
435{
436 unsigned int i;
437
438 if (oid1len != oid2len)
439 return 0;
440 else {
441 for (i = 0; i < oid1len; i++) {
442 if (oid1[i] != oid2[i])
443 return 0;
444 }
445 return 1;
446 }
447}
448
449 /* BB check for endian conversion issues here */
450
451int
452decode_negTokenInit(unsigned char *security_blob, int length,
453 enum securityEnum *secType)
454{
455 struct asn1_ctx ctx;
456 unsigned char *end;
457 unsigned char *sequence_end;
458 unsigned long *oid = NULL;
459 unsigned int cls, con, tag, oidlen, rc;
460 int use_ntlmssp = FALSE;
461
462 *secType = NTLM; /* BB eventually make Kerberos or NLTMSSP the default */
463
464 /* cifs_dump_mem(" Received SecBlob ", security_blob, length); */
465
466 asn1_open(&ctx, security_blob, length);
467
468 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
469 cFYI(1, ("Error decoding negTokenInit header "));
470 return 0;
471 } else if ((cls != ASN1_APL) || (con != ASN1_CON)
472 || (tag != ASN1_EOC)) {
473 cFYI(1, ("cls = %d con = %d tag = %d", cls, con, tag));
474 return 0;
475 } else {
476 /* remember to free obj->oid */
477 rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
478 if (rc) {
479 if ((tag == ASN1_OJI) && (cls == ASN1_PRI)) {
480 rc = asn1_oid_decode(&ctx, end, &oid, &oidlen);
481 if (rc) {
482 rc = compare_oid(oid, oidlen,
483 SPNEGO_OID,
484 SPNEGO_OID_LEN);
485 kfree(oid);
486 }
487 } else
488 rc = 0;
489 }
490
491 if (!rc) {
492 cFYI(1, ("Error decoding negTokenInit header"));
493 return 0;
494 }
495
496 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
497 cFYI(1, ("Error decoding negTokenInit "));
498 return 0;
499 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
500 || (tag != ASN1_EOC)) {
501 cFYI(1,("cls = %d con = %d tag = %d end = %p (%d) exit 0",
502 cls, con, tag, end, *end));
503 return 0;
504 }
505
506 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
507 cFYI(1, ("Error decoding negTokenInit "));
508 return 0;
509 } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
510 || (tag != ASN1_SEQ)) {
511 cFYI(1,("cls = %d con = %d tag = %d end = %p (%d) exit 1",
512 cls, con, tag, end, *end));
513 return 0;
514 }
515
516 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
517 cFYI(1, ("Error decoding 2nd part of negTokenInit "));
518 return 0;
519 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
520 || (tag != ASN1_EOC)) {
521 cFYI(1,
522 ("cls = %d con = %d tag = %d end = %p (%d) exit 0",
523 cls, con, tag, end, *end));
524 return 0;
525 }
526
527 if (asn1_header_decode
528 (&ctx, &sequence_end, &cls, &con, &tag) == 0) {
529 cFYI(1, ("Error decoding 2nd part of negTokenInit "));
530 return 0;
531 } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
532 || (tag != ASN1_SEQ)) {
533 cFYI(1,
534 ("cls = %d con = %d tag = %d end = %p (%d) exit 1",
535 cls, con, tag, end, *end));
536 return 0;
537 }
538
539 while (!asn1_eoc_decode(&ctx, sequence_end)) {
540 rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
541 if (!rc) {
542 cFYI(1,
543 ("Error 1 decoding negTokenInit header exit 2"));
544 return 0;
545 }
546 if ((tag == ASN1_OJI) && (con == ASN1_PRI)) {
547 rc = asn1_oid_decode(&ctx, end, &oid, &oidlen);
548 if(rc) {
549 cFYI(1,
550 ("OID len = %d oid = 0x%lx 0x%lx 0x%lx 0x%lx",
551 oidlen, *oid, *(oid + 1), *(oid + 2),
552 *(oid + 3)));
553 rc = compare_oid(oid, oidlen, NTLMSSP_OID,
554 NTLMSSP_OID_LEN);
555 if(oid)
556 kfree(oid);
557 if (rc)
558 use_ntlmssp = TRUE;
559 }
560 } else {
561 cFYI(1,("This should be an oid what is going on? "));
562 }
563 }
564
565 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
566 cFYI(1,
567 ("Error decoding last part of negTokenInit exit 3"));
568 return 0;
569 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) { /* tag = 3 indicating mechListMIC */
570 cFYI(1,
571 ("Exit 4 cls = %d con = %d tag = %d end = %p (%d)",
572 cls, con, tag, end, *end));
573 return 0;
574 }
575 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
576 cFYI(1,
577 ("Error decoding last part of negTokenInit exit 5"));
578 return 0;
579 } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
580 || (tag != ASN1_SEQ)) {
581 cFYI(1,
582 ("Exit 6 cls = %d con = %d tag = %d end = %p (%d)",
583 cls, con, tag, end, *end));
584 }
585
586 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
587 cFYI(1,
588 ("Error decoding last part of negTokenInit exit 7"));
589 return 0;
590 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) {
591 cFYI(1,
592 ("Exit 8 cls = %d con = %d tag = %d end = %p (%d)",
593 cls, con, tag, end, *end));
594 return 0;
595 }
596 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
597 cFYI(1,
598 ("Error decoding last part of negTokenInit exit 9"));
599 return 0;
600 } else if ((cls != ASN1_UNI) || (con != ASN1_PRI)
601 || (tag != ASN1_GENSTR)) {
602 cFYI(1,
603 ("Exit 10 cls = %d con = %d tag = %d end = %p (%d)",
604 cls, con, tag, end, *end));
605 return 0;
606 }
607 cFYI(1, ("Need to call asn1_octets_decode() function for this %s", ctx.pointer)); /* is this UTF-8 or ASCII? */
608 }
609
610 /* if (use_kerberos)
611 *secType = Kerberos
612 else */
613 if (use_ntlmssp) {
614 *secType = NTLMSSP;
615 }
616
617 return 1;
618}