Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[linux-2.6/libata-dev.git] / fs / cifs / asn1.c
bloba20bea598933459f24bed25f64ade645dea18ca9
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
5 * Copyright (c) 2000 RP Internet (www.rpi.net.au).
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
20 #include <linux/module.h>
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/slab.h>
25 #include "cifspdu.h"
26 #include "cifsglob.h"
27 #include "cifs_debug.h"
28 #include "cifsproto.h"
30 /*****************************************************************************
32 * Basic ASN.1 decoding routines (gxsnmp author Dirk Wisse)
34 *****************************************************************************/
36 /* Class */
37 #define ASN1_UNI 0 /* Universal */
38 #define ASN1_APL 1 /* Application */
39 #define ASN1_CTX 2 /* Context */
40 #define ASN1_PRV 3 /* Private */
42 /* Tag */
43 #define ASN1_EOC 0 /* End Of Contents or N/A */
44 #define ASN1_BOL 1 /* Boolean */
45 #define ASN1_INT 2 /* Integer */
46 #define ASN1_BTS 3 /* Bit String */
47 #define ASN1_OTS 4 /* Octet String */
48 #define ASN1_NUL 5 /* Null */
49 #define ASN1_OJI 6 /* Object Identifier */
50 #define ASN1_OJD 7 /* Object Description */
51 #define ASN1_EXT 8 /* External */
52 #define ASN1_ENUM 10 /* Enumerated */
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 */
66 /* Primitive / Constructed methods*/
67 #define ASN1_PRI 0 /* Primitive */
68 #define ASN1_CON 1 /* Constructed */
71 * Error codes.
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
79 #define SPNEGO_OID_LEN 7
80 #define NTLMSSP_OID_LEN 10
81 #define KRB5_OID_LEN 7
82 #define KRB5U2U_OID_LEN 8
83 #define MSKRB5_OID_LEN 7
84 static unsigned long SPNEGO_OID[7] = { 1, 3, 6, 1, 5, 5, 2 };
85 static unsigned long NTLMSSP_OID[10] = { 1, 3, 6, 1, 4, 1, 311, 2, 2, 10 };
86 static unsigned long KRB5_OID[7] = { 1, 2, 840, 113554, 1, 2, 2 };
87 static unsigned long KRB5U2U_OID[8] = { 1, 2, 840, 113554, 1, 2, 2, 3 };
88 static unsigned long MSKRB5_OID[7] = { 1, 2, 840, 48018, 1, 2, 2 };
91 * ASN.1 context.
93 struct asn1_ctx {
94 int error; /* Error condition */
95 unsigned char *pointer; /* Octet just to be decoded */
96 unsigned char *begin; /* First octet */
97 unsigned char *end; /* Octet after last octet */
101 * Octet string (not null terminated)
103 struct asn1_octstr {
104 unsigned char *data;
105 unsigned int len;
108 static void
109 asn1_open(struct asn1_ctx *ctx, unsigned char *buf, unsigned int len)
111 ctx->begin = buf;
112 ctx->end = buf + len;
113 ctx->pointer = buf;
114 ctx->error = ASN1_ERR_NOERROR;
117 static unsigned char
118 asn1_octet_decode(struct asn1_ctx *ctx, unsigned char *ch)
120 if (ctx->pointer >= ctx->end) {
121 ctx->error = ASN1_ERR_DEC_EMPTY;
122 return 0;
124 *ch = *(ctx->pointer)++;
125 return 1;
128 #if 0 /* will be needed later by spnego decoding/encoding of ntlmssp */
129 static unsigned char
130 asn1_enum_decode(struct asn1_ctx *ctx, __le32 *val)
132 unsigned char ch;
134 if (ctx->pointer >= ctx->end) {
135 ctx->error = ASN1_ERR_DEC_EMPTY;
136 return 0;
139 ch = *(ctx->pointer)++; /* ch has 0xa, ptr points to length octet */
140 if ((ch) == ASN1_ENUM) /* if ch value is ENUM, 0xa */
141 *val = *(++(ctx->pointer)); /* value has enum value */
142 else
143 return 0;
145 ctx->pointer++;
146 return 1;
148 #endif
150 static unsigned char
151 asn1_tag_decode(struct asn1_ctx *ctx, unsigned int *tag)
153 unsigned char ch;
155 *tag = 0;
157 do {
158 if (!asn1_octet_decode(ctx, &ch))
159 return 0;
160 *tag <<= 7;
161 *tag |= ch & 0x7F;
162 } while ((ch & 0x80) == 0x80);
163 return 1;
166 static unsigned char
167 asn1_id_decode(struct asn1_ctx *ctx,
168 unsigned int *cls, unsigned int *con, unsigned int *tag)
170 unsigned char ch;
172 if (!asn1_octet_decode(ctx, &ch))
173 return 0;
175 *cls = (ch & 0xC0) >> 6;
176 *con = (ch & 0x20) >> 5;
177 *tag = (ch & 0x1F);
179 if (*tag == 0x1F) {
180 if (!asn1_tag_decode(ctx, tag))
181 return 0;
183 return 1;
186 static unsigned char
187 asn1_length_decode(struct asn1_ctx *ctx, unsigned int *def, unsigned int *len)
189 unsigned char ch, cnt;
191 if (!asn1_octet_decode(ctx, &ch))
192 return 0;
194 if (ch == 0x80)
195 *def = 0;
196 else {
197 *def = 1;
199 if (ch < 0x80)
200 *len = ch;
201 else {
202 cnt = (unsigned char) (ch & 0x7F);
203 *len = 0;
205 while (cnt > 0) {
206 if (!asn1_octet_decode(ctx, &ch))
207 return 0;
208 *len <<= 8;
209 *len |= ch;
210 cnt--;
215 /* don't trust len bigger than ctx buffer */
216 if (*len > ctx->end - ctx->pointer)
217 return 0;
219 return 1;
222 static unsigned char
223 asn1_header_decode(struct asn1_ctx *ctx,
224 unsigned char **eoc,
225 unsigned int *cls, unsigned int *con, unsigned int *tag)
227 unsigned int def = 0;
228 unsigned int len = 0;
230 if (!asn1_id_decode(ctx, cls, con, tag))
231 return 0;
233 if (!asn1_length_decode(ctx, &def, &len))
234 return 0;
236 /* primitive shall be definite, indefinite shall be constructed */
237 if (*con == ASN1_PRI && !def)
238 return 0;
240 if (def)
241 *eoc = ctx->pointer + len;
242 else
243 *eoc = NULL;
244 return 1;
247 static unsigned char
248 asn1_eoc_decode(struct asn1_ctx *ctx, unsigned char *eoc)
250 unsigned char ch;
252 if (eoc == NULL) {
253 if (!asn1_octet_decode(ctx, &ch))
254 return 0;
256 if (ch != 0x00) {
257 ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
258 return 0;
261 if (!asn1_octet_decode(ctx, &ch))
262 return 0;
264 if (ch != 0x00) {
265 ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
266 return 0;
268 return 1;
269 } else {
270 if (ctx->pointer != eoc) {
271 ctx->error = ASN1_ERR_DEC_LENGTH_MISMATCH;
272 return 0;
274 return 1;
278 /* static unsigned char asn1_null_decode(struct asn1_ctx *ctx,
279 unsigned char *eoc)
281 ctx->pointer = eoc;
282 return 1;
285 static unsigned char asn1_long_decode(struct asn1_ctx *ctx,
286 unsigned char *eoc, long *integer)
288 unsigned char ch;
289 unsigned int len;
291 if (!asn1_octet_decode(ctx, &ch))
292 return 0;
294 *integer = (signed char) ch;
295 len = 1;
297 while (ctx->pointer < eoc) {
298 if (++len > sizeof(long)) {
299 ctx->error = ASN1_ERR_DEC_BADVALUE;
300 return 0;
303 if (!asn1_octet_decode(ctx, &ch))
304 return 0;
306 *integer <<= 8;
307 *integer |= ch;
309 return 1;
312 static unsigned char asn1_uint_decode(struct asn1_ctx *ctx,
313 unsigned char *eoc,
314 unsigned int *integer)
316 unsigned char ch;
317 unsigned int len;
319 if (!asn1_octet_decode(ctx, &ch))
320 return 0;
322 *integer = ch;
323 if (ch == 0)
324 len = 0;
325 else
326 len = 1;
328 while (ctx->pointer < eoc) {
329 if (++len > sizeof(unsigned int)) {
330 ctx->error = ASN1_ERR_DEC_BADVALUE;
331 return 0;
334 if (!asn1_octet_decode(ctx, &ch))
335 return 0;
337 *integer <<= 8;
338 *integer |= ch;
340 return 1;
343 static unsigned char asn1_ulong_decode(struct asn1_ctx *ctx,
344 unsigned char *eoc,
345 unsigned long *integer)
347 unsigned char ch;
348 unsigned int len;
350 if (!asn1_octet_decode(ctx, &ch))
351 return 0;
353 *integer = ch;
354 if (ch == 0)
355 len = 0;
356 else
357 len = 1;
359 while (ctx->pointer < eoc) {
360 if (++len > sizeof(unsigned long)) {
361 ctx->error = ASN1_ERR_DEC_BADVALUE;
362 return 0;
365 if (!asn1_octet_decode(ctx, &ch))
366 return 0;
368 *integer <<= 8;
369 *integer |= ch;
371 return 1;
374 static unsigned char
375 asn1_octets_decode(struct asn1_ctx *ctx,
376 unsigned char *eoc,
377 unsigned char **octets, unsigned int *len)
379 unsigned char *ptr;
381 *len = 0;
383 *octets = kmalloc(eoc - ctx->pointer, GFP_ATOMIC);
384 if (*octets == NULL) {
385 return 0;
388 ptr = *octets;
389 while (ctx->pointer < eoc) {
390 if (!asn1_octet_decode(ctx, (unsigned char *) ptr++)) {
391 kfree(*octets);
392 *octets = NULL;
393 return 0;
395 (*len)++;
397 return 1;
398 } */
400 static unsigned char
401 asn1_subid_decode(struct asn1_ctx *ctx, unsigned long *subid)
403 unsigned char ch;
405 *subid = 0;
407 do {
408 if (!asn1_octet_decode(ctx, &ch))
409 return 0;
411 *subid <<= 7;
412 *subid |= ch & 0x7F;
413 } while ((ch & 0x80) == 0x80);
414 return 1;
417 static int
418 asn1_oid_decode(struct asn1_ctx *ctx,
419 unsigned char *eoc, unsigned long **oid, unsigned int *len)
421 unsigned long subid;
422 unsigned int size;
423 unsigned long *optr;
425 size = eoc - ctx->pointer + 1;
427 /* first subid actually encodes first two subids */
428 if (size < 2 || size > UINT_MAX/sizeof(unsigned long))
429 return 0;
431 *oid = kmalloc(size * sizeof(unsigned long), GFP_ATOMIC);
432 if (*oid == NULL)
433 return 0;
435 optr = *oid;
437 if (!asn1_subid_decode(ctx, &subid)) {
438 kfree(*oid);
439 *oid = NULL;
440 return 0;
443 if (subid < 40) {
444 optr[0] = 0;
445 optr[1] = subid;
446 } else if (subid < 80) {
447 optr[0] = 1;
448 optr[1] = subid - 40;
449 } else {
450 optr[0] = 2;
451 optr[1] = subid - 80;
454 *len = 2;
455 optr += 2;
457 while (ctx->pointer < eoc) {
458 if (++(*len) > size) {
459 ctx->error = ASN1_ERR_DEC_BADVALUE;
460 kfree(*oid);
461 *oid = NULL;
462 return 0;
465 if (!asn1_subid_decode(ctx, optr++)) {
466 kfree(*oid);
467 *oid = NULL;
468 return 0;
471 return 1;
474 static int
475 compare_oid(unsigned long *oid1, unsigned int oid1len,
476 unsigned long *oid2, unsigned int oid2len)
478 unsigned int i;
480 if (oid1len != oid2len)
481 return 0;
482 else {
483 for (i = 0; i < oid1len; i++) {
484 if (oid1[i] != oid2[i])
485 return 0;
487 return 1;
491 /* BB check for endian conversion issues here */
494 decode_negTokenInit(unsigned char *security_blob, int length,
495 enum securityEnum *secType)
497 struct asn1_ctx ctx;
498 unsigned char *end;
499 unsigned char *sequence_end;
500 unsigned long *oid = NULL;
501 unsigned int cls, con, tag, oidlen, rc;
502 bool use_ntlmssp = false;
503 bool use_kerberos = false;
504 bool use_kerberosu2u = false;
505 bool use_mskerberos = false;
507 /* cifs_dump_mem(" Received SecBlob ", security_blob, length); */
509 asn1_open(&ctx, security_blob, length);
511 /* GSSAPI header */
512 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
513 cFYI(1, ("Error decoding negTokenInit header"));
514 return 0;
515 } else if ((cls != ASN1_APL) || (con != ASN1_CON)
516 || (tag != ASN1_EOC)) {
517 cFYI(1, ("cls = %d con = %d tag = %d", cls, con, tag));
518 return 0;
521 /* Check for SPNEGO OID -- remember to free obj->oid */
522 rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
523 if (rc) {
524 if ((tag == ASN1_OJI) && (con == ASN1_PRI) &&
525 (cls == ASN1_UNI)) {
526 rc = asn1_oid_decode(&ctx, end, &oid, &oidlen);
527 if (rc) {
528 rc = compare_oid(oid, oidlen, SPNEGO_OID,
529 SPNEGO_OID_LEN);
530 kfree(oid);
532 } else
533 rc = 0;
536 /* SPNEGO OID not present or garbled -- bail out */
537 if (!rc) {
538 cFYI(1, ("Error decoding negTokenInit header"));
539 return 0;
542 /* SPNEGO */
543 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
544 cFYI(1, ("Error decoding negTokenInit"));
545 return 0;
546 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
547 || (tag != ASN1_EOC)) {
548 cFYI(1,
549 ("cls = %d con = %d tag = %d end = %p (%d) exit 0",
550 cls, con, tag, end, *end));
551 return 0;
554 /* negTokenInit */
555 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
556 cFYI(1, ("Error decoding negTokenInit"));
557 return 0;
558 } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
559 || (tag != ASN1_SEQ)) {
560 cFYI(1,
561 ("cls = %d con = %d tag = %d end = %p (%d) exit 1",
562 cls, con, tag, end, *end));
563 return 0;
566 /* sequence */
567 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
568 cFYI(1, ("Error decoding 2nd part of negTokenInit"));
569 return 0;
570 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
571 || (tag != ASN1_EOC)) {
572 cFYI(1,
573 ("cls = %d con = %d tag = %d end = %p (%d) exit 0",
574 cls, con, tag, end, *end));
575 return 0;
578 /* sequence of */
579 if (asn1_header_decode
580 (&ctx, &sequence_end, &cls, &con, &tag) == 0) {
581 cFYI(1, ("Error decoding 2nd part of negTokenInit"));
582 return 0;
583 } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
584 || (tag != ASN1_SEQ)) {
585 cFYI(1,
586 ("cls = %d con = %d tag = %d end = %p (%d) exit 1",
587 cls, con, tag, end, *end));
588 return 0;
591 /* list of security mechanisms */
592 while (!asn1_eoc_decode(&ctx, sequence_end)) {
593 rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
594 if (!rc) {
595 cFYI(1,
596 ("Error decoding negTokenInit hdr exit2"));
597 return 0;
599 if ((tag == ASN1_OJI) && (con == ASN1_PRI)) {
600 if (asn1_oid_decode(&ctx, end, &oid, &oidlen)) {
602 cFYI(1, ("OID len = %d oid = 0x%lx 0x%lx "
603 "0x%lx 0x%lx", oidlen, *oid,
604 *(oid + 1), *(oid + 2), *(oid + 3)));
606 if (compare_oid(oid, oidlen, MSKRB5_OID,
607 MSKRB5_OID_LEN) &&
608 !use_mskerberos)
609 use_mskerberos = true;
610 else if (compare_oid(oid, oidlen, KRB5U2U_OID,
611 KRB5U2U_OID_LEN) &&
612 !use_kerberosu2u)
613 use_kerberosu2u = true;
614 else if (compare_oid(oid, oidlen, KRB5_OID,
615 KRB5_OID_LEN) &&
616 !use_kerberos)
617 use_kerberos = true;
618 else if (compare_oid(oid, oidlen, NTLMSSP_OID,
619 NTLMSSP_OID_LEN))
620 use_ntlmssp = true;
622 kfree(oid);
624 } else {
625 cFYI(1, ("Should be an oid what is going on?"));
629 /* mechlistMIC */
630 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
631 /* Check if we have reached the end of the blob, but with
632 no mechListMic (e.g. NTLMSSP instead of KRB5) */
633 if (ctx.error == ASN1_ERR_DEC_EMPTY)
634 goto decode_negtoken_exit;
635 cFYI(1, ("Error decoding last part negTokenInit exit3"));
636 return 0;
637 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) {
638 /* tag = 3 indicating mechListMIC */
639 cFYI(1, ("Exit 4 cls = %d con = %d tag = %d end = %p (%d)",
640 cls, con, tag, end, *end));
641 return 0;
644 /* sequence */
645 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
646 cFYI(1, ("Error decoding last part negTokenInit exit5"));
647 return 0;
648 } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
649 || (tag != ASN1_SEQ)) {
650 cFYI(1, ("cls = %d con = %d tag = %d end = %p (%d)",
651 cls, con, tag, end, *end));
654 /* sequence of */
655 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
656 cFYI(1, ("Error decoding last part negTokenInit exit 7"));
657 return 0;
658 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) {
659 cFYI(1, ("Exit 8 cls = %d con = %d tag = %d end = %p (%d)",
660 cls, con, tag, end, *end));
661 return 0;
664 /* general string */
665 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
666 cFYI(1, ("Error decoding last part negTokenInit exit9"));
667 return 0;
668 } else if ((cls != ASN1_UNI) || (con != ASN1_PRI)
669 || (tag != ASN1_GENSTR)) {
670 cFYI(1, ("Exit10 cls = %d con = %d tag = %d end = %p (%d)",
671 cls, con, tag, end, *end));
672 return 0;
674 cFYI(1, ("Need to call asn1_octets_decode() function for %s",
675 ctx.pointer)); /* is this UTF-8 or ASCII? */
676 decode_negtoken_exit:
677 if (use_kerberos)
678 *secType = Kerberos;
679 else if (use_mskerberos)
680 *secType = MSKerberos;
681 else if (use_ntlmssp)
682 *secType = RawNTLMSSP;
684 return 1;