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>
24 #include <linux/slab.h>
27 #include "cifs_debug.h"
28 #include "cifsproto.h"
30 /*****************************************************************************
32 * Basic ASN.1 decoding routines (gxsnmp author Dirk Wisse)
34 *****************************************************************************/
37 #define ASN1_UNI 0 /* Universal */
38 #define ASN1_APL 1 /* Application */
39 #define ASN1_CTX 2 /* Context */
40 #define ASN1_PRV 3 /* Private */
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 */
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 };
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)
109 asn1_open(struct asn1_ctx *ctx, unsigned char *buf, unsigned int len)
112 ctx->end = buf + len;
114 ctx->error = ASN1_ERR_NOERROR;
118 asn1_octet_decode(struct asn1_ctx *ctx, unsigned char *ch)
120 if (ctx->pointer >= ctx->end) {
121 ctx->error = ASN1_ERR_DEC_EMPTY;
124 *ch = *(ctx->pointer)++;
128 #if 0 /* will be needed later by spnego decoding/encoding of ntlmssp */
130 asn1_enum_decode(struct asn1_ctx *ctx, __le32 *val)
134 if (ctx->pointer >= ctx->end) {
135 ctx->error = ASN1_ERR_DEC_EMPTY;
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 */
151 asn1_tag_decode(struct asn1_ctx *ctx, unsigned int *tag)
158 if (!asn1_octet_decode(ctx, &ch))
162 } while ((ch & 0x80) == 0x80);
167 asn1_id_decode(struct asn1_ctx *ctx,
168 unsigned int *cls, unsigned int *con, unsigned int *tag)
172 if (!asn1_octet_decode(ctx, &ch))
175 *cls = (ch & 0xC0) >> 6;
176 *con = (ch & 0x20) >> 5;
180 if (!asn1_tag_decode(ctx, tag))
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))
202 cnt = (unsigned char) (ch & 0x7F);
206 if (!asn1_octet_decode(ctx, &ch))
215 /* don't trust len bigger than ctx buffer */
216 if (*len > ctx->end - ctx->pointer)
223 asn1_header_decode(struct asn1_ctx *ctx,
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))
233 if (!asn1_length_decode(ctx, &def, &len))
236 /* primitive shall be definite, indefinite shall be constructed */
237 if (*con == ASN1_PRI && !def)
241 *eoc = ctx->pointer + len;
248 asn1_eoc_decode(struct asn1_ctx *ctx, unsigned char *eoc)
253 if (!asn1_octet_decode(ctx, &ch))
257 ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
261 if (!asn1_octet_decode(ctx, &ch))
265 ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
270 if (ctx->pointer != eoc) {
271 ctx->error = ASN1_ERR_DEC_LENGTH_MISMATCH;
278 /* static unsigned char asn1_null_decode(struct asn1_ctx *ctx,
285 static unsigned char asn1_long_decode(struct asn1_ctx *ctx,
286 unsigned char *eoc, long *integer)
291 if (!asn1_octet_decode(ctx, &ch))
294 *integer = (signed char) ch;
297 while (ctx->pointer < eoc) {
298 if (++len > sizeof(long)) {
299 ctx->error = ASN1_ERR_DEC_BADVALUE;
303 if (!asn1_octet_decode(ctx, &ch))
312 static unsigned char asn1_uint_decode(struct asn1_ctx *ctx,
314 unsigned int *integer)
319 if (!asn1_octet_decode(ctx, &ch))
328 while (ctx->pointer < eoc) {
329 if (++len > sizeof(unsigned int)) {
330 ctx->error = ASN1_ERR_DEC_BADVALUE;
334 if (!asn1_octet_decode(ctx, &ch))
343 static unsigned char asn1_ulong_decode(struct asn1_ctx *ctx,
345 unsigned long *integer)
350 if (!asn1_octet_decode(ctx, &ch))
359 while (ctx->pointer < eoc) {
360 if (++len > sizeof(unsigned long)) {
361 ctx->error = ASN1_ERR_DEC_BADVALUE;
365 if (!asn1_octet_decode(ctx, &ch))
375 asn1_octets_decode(struct asn1_ctx *ctx,
377 unsigned char **octets, unsigned int *len)
383 *octets = kmalloc(eoc - ctx->pointer, GFP_ATOMIC);
384 if (*octets == NULL) {
389 while (ctx->pointer < eoc) {
390 if (!asn1_octet_decode(ctx, (unsigned char *) ptr++)) {
401 asn1_subid_decode(struct asn1_ctx *ctx, unsigned long *subid)
408 if (!asn1_octet_decode(ctx, &ch))
413 } while ((ch & 0x80) == 0x80);
418 asn1_oid_decode(struct asn1_ctx *ctx,
419 unsigned char *eoc, unsigned long **oid, unsigned int *len)
425 size = eoc - ctx->pointer + 1;
427 /* first subid actually encodes first two subids */
428 if (size < 2 || size > UINT_MAX/sizeof(unsigned long))
431 *oid = kmalloc(size * sizeof(unsigned long), GFP_ATOMIC);
437 if (!asn1_subid_decode(ctx, &subid)) {
446 } else if (subid < 80) {
448 optr[1] = subid - 40;
451 optr[1] = subid - 80;
457 while (ctx->pointer < eoc) {
458 if (++(*len) > size) {
459 ctx->error = ASN1_ERR_DEC_BADVALUE;
465 if (!asn1_subid_decode(ctx, optr++)) {
475 compare_oid(unsigned long *oid1, unsigned int oid1len,
476 unsigned long *oid2, unsigned int oid2len)
480 if (oid1len != oid2len)
483 for (i = 0; i < oid1len; i++) {
484 if (oid1[i] != oid2[i])
491 /* BB check for endian conversion issues here */
494 decode_negTokenInit(unsigned char *security_blob, int length,
495 struct TCP_Server_Info *server)
499 unsigned char *sequence_end;
500 unsigned long *oid = NULL;
501 unsigned int cls, con, tag, oidlen, rc;
503 /* cifs_dump_mem(" Received SecBlob ", security_blob, length); */
505 asn1_open(&ctx, security_blob, length);
508 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
509 cFYI(1, "Error decoding negTokenInit header");
511 } else if ((cls != ASN1_APL) || (con != ASN1_CON)
512 || (tag != ASN1_EOC)) {
513 cFYI(1, "cls = %d con = %d tag = %d", cls, con, tag);
517 /* Check for SPNEGO OID -- remember to free obj->oid */
518 rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
520 if ((tag == ASN1_OJI) && (con == ASN1_PRI) &&
522 rc = asn1_oid_decode(&ctx, end, &oid, &oidlen);
524 rc = compare_oid(oid, oidlen, SPNEGO_OID,
532 /* SPNEGO OID not present or garbled -- bail out */
534 cFYI(1, "Error decoding negTokenInit header");
539 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
540 cFYI(1, "Error decoding negTokenInit");
542 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
543 || (tag != ASN1_EOC)) {
544 cFYI(1, "cls = %d con = %d tag = %d end = %p (%d) exit 0",
545 cls, con, tag, end, *end);
550 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
551 cFYI(1, "Error decoding negTokenInit");
553 } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
554 || (tag != ASN1_SEQ)) {
555 cFYI(1, "cls = %d con = %d tag = %d end = %p (%d) exit 1",
556 cls, con, tag, end, *end);
561 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
562 cFYI(1, "Error decoding 2nd part of negTokenInit");
564 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)
565 || (tag != ASN1_EOC)) {
566 cFYI(1, "cls = %d con = %d tag = %d end = %p (%d) exit 0",
567 cls, con, tag, end, *end);
572 if (asn1_header_decode
573 (&ctx, &sequence_end, &cls, &con, &tag) == 0) {
574 cFYI(1, "Error decoding 2nd part of negTokenInit");
576 } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
577 || (tag != ASN1_SEQ)) {
578 cFYI(1, "cls = %d con = %d tag = %d end = %p (%d) exit 1",
579 cls, con, tag, end, *end);
583 /* list of security mechanisms */
584 while (!asn1_eoc_decode(&ctx, sequence_end)) {
585 rc = asn1_header_decode(&ctx, &end, &cls, &con, &tag);
587 cFYI(1, "Error decoding negTokenInit hdr exit2");
590 if ((tag == ASN1_OJI) && (con == ASN1_PRI)) {
591 if (asn1_oid_decode(&ctx, end, &oid, &oidlen)) {
593 cFYI(1, "OID len = %d oid = 0x%lx 0x%lx "
594 "0x%lx 0x%lx", oidlen, *oid,
595 *(oid + 1), *(oid + 2), *(oid + 3));
597 if (compare_oid(oid, oidlen, MSKRB5_OID,
599 server->sec_mskerberos = true;
600 else if (compare_oid(oid, oidlen, KRB5U2U_OID,
602 server->sec_kerberosu2u = true;
603 else if (compare_oid(oid, oidlen, KRB5_OID,
605 server->sec_kerberos = true;
606 else if (compare_oid(oid, oidlen, NTLMSSP_OID,
608 server->sec_ntlmssp = true;
613 cFYI(1, "Should be an oid what is going on?");
618 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
619 /* Check if we have reached the end of the blob, but with
620 no mechListMic (e.g. NTLMSSP instead of KRB5) */
621 if (ctx.error == ASN1_ERR_DEC_EMPTY)
622 goto decode_negtoken_exit;
623 cFYI(1, "Error decoding last part negTokenInit exit3");
625 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) {
626 /* tag = 3 indicating mechListMIC */
627 cFYI(1, "Exit 4 cls = %d con = %d tag = %d end = %p (%d)",
628 cls, con, tag, end, *end);
633 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
634 cFYI(1, "Error decoding last part negTokenInit exit5");
636 } else if ((cls != ASN1_UNI) || (con != ASN1_CON)
637 || (tag != ASN1_SEQ)) {
638 cFYI(1, "cls = %d con = %d tag = %d end = %p (%d)",
639 cls, con, tag, end, *end);
643 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
644 cFYI(1, "Error decoding last part negTokenInit exit 7");
646 } else if ((cls != ASN1_CTX) || (con != ASN1_CON)) {
647 cFYI(1, "Exit 8 cls = %d con = %d tag = %d end = %p (%d)",
648 cls, con, tag, end, *end);
653 if (asn1_header_decode(&ctx, &end, &cls, &con, &tag) == 0) {
654 cFYI(1, "Error decoding last part negTokenInit exit9");
656 } else if ((cls != ASN1_UNI) || (con != ASN1_PRI)
657 || (tag != ASN1_GENSTR)) {
658 cFYI(1, "Exit10 cls = %d con = %d tag = %d end = %p (%d)",
659 cls, con, tag, end, *end);
662 cFYI(1, "Need to call asn1_octets_decode() function for %s",
663 ctx.pointer); /* is this UTF-8 or ASCII? */
664 decode_negtoken_exit: