source: vendor/current/source3/libsmb/clispnego.c

Last change on this file was 988, checked in by Silvan Scherrer, 9 years ago

Samba Server: update vendor to version 4.4.3
File size: 5.0 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) Luke Howard 2003
7 Copyright (C) Jeremy Allison 2010
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
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 "../libcli/auth/spnego.h"
25#include "smb_krb5.h"
26#include "../lib/util/asn1.h"
27
28/*
29 parse a negTokenInit packet giving a GUID, a list of supported
30 OIDs (the mechanisms) and a principal name string
31*/
32bool spnego_parse_negTokenInit(TALLOC_CTX *ctx,
33 DATA_BLOB blob,
34 char *OIDs[ASN1_MAX_OIDS],
35 char **principal,
36 DATA_BLOB *secblob)
37{
38 int i;
39 bool ret = false;
40 ASN1_DATA *data;
41
42 for (i = 0; i < ASN1_MAX_OIDS; i++) {
43 OIDs[i] = NULL;
44 }
45
46 if (principal) {
47 *principal = NULL;
48 }
49 if (secblob) {
50 *secblob = data_blob_null;
51 }
52
53 data = asn1_init(talloc_tos());
54 if (data == NULL) {
55 return false;
56 }
57
58 if (!asn1_load(data, blob)) goto err;
59
60 if (!asn1_start_tag(data,ASN1_APPLICATION(0))) goto err;
61
62 if (!asn1_check_OID(data,OID_SPNEGO)) goto err;
63
64 /* negTokenInit [0] NegTokenInit */
65 if (!asn1_start_tag(data,ASN1_CONTEXT(0))) goto err;
66 if (!asn1_start_tag(data,ASN1_SEQUENCE(0))) goto err;
67
68 /* mechTypes [0] MechTypeList OPTIONAL */
69
70 /* Not really optional, we depend on this to decide
71 * what mechanisms we have to work with. */
72
73 if (!asn1_start_tag(data,ASN1_CONTEXT(0))) goto err;
74 if (!asn1_start_tag(data,ASN1_SEQUENCE(0))) goto err;
75 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
76 if (!asn1_read_OID(data,ctx, &OIDs[i])) {
77 goto err;
78 }
79 if (asn1_has_error(data)) {
80 goto err;
81 }
82 }
83 OIDs[i] = NULL;
84 if (!asn1_end_tag(data)) goto err;
85 if (!asn1_end_tag(data)) goto err;
86
87 /*
88 Win7 + Live Sign-in Assistant attaches a mechToken
89 ASN1_CONTEXT(2) to the negTokenInit packet
90 which breaks our negotiation if we just assume
91 the next tag is ASN1_CONTEXT(3).
92 */
93
94 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
95 uint8_t flags;
96
97 /* reqFlags [1] ContextFlags OPTIONAL */
98 if (!asn1_start_tag(data, ASN1_CONTEXT(1))) goto err;
99 if (!asn1_start_tag(data, ASN1_BIT_STRING)) goto err;
100 while (asn1_tag_remaining(data) > 0) {
101 if (!asn1_read_uint8(data, &flags)) goto err;
102 }
103 if (!asn1_end_tag(data)) goto err;
104 if (!asn1_end_tag(data)) goto err;
105 }
106
107 if (asn1_peek_tag(data, ASN1_CONTEXT(2))) {
108 DATA_BLOB sblob = data_blob_null;
109 /* mechToken [2] OCTET STRING OPTIONAL */
110 if (!asn1_start_tag(data, ASN1_CONTEXT(2))) goto err;
111 if (!asn1_read_OctetString(data, ctx, &sblob)) goto err;
112 if (!asn1_end_tag(data)) {
113 data_blob_free(&sblob);
114 goto err;
115 }
116 if (secblob) {
117 *secblob = sblob;
118 } else {
119 data_blob_free(&sblob);
120 }
121 }
122
123 if (asn1_peek_tag(data, ASN1_CONTEXT(3))) {
124 char *princ = NULL;
125 /* mechListMIC [3] OCTET STRING OPTIONAL */
126 if (!asn1_start_tag(data, ASN1_CONTEXT(3))) goto err;
127 if (!asn1_start_tag(data, ASN1_SEQUENCE(0))) goto err;
128 if (!asn1_start_tag(data, ASN1_CONTEXT(0))) goto err;
129 if (!asn1_read_GeneralString(data, ctx, &princ)) goto err;
130 if (!asn1_end_tag(data)) goto err;
131 if (!asn1_end_tag(data)) goto err;
132 if (!asn1_end_tag(data)) goto err;
133 if (principal) {
134 *principal = princ;
135 } else {
136 TALLOC_FREE(princ);
137 }
138 }
139
140 if (!asn1_end_tag(data)) goto err;
141 if (!asn1_end_tag(data)) goto err;
142
143 if (!asn1_end_tag(data)) goto err;
144
145 ret = !asn1_has_error(data);
146
147 err:
148
149 if (asn1_has_error(data)) {
150 int j;
151 if (principal) {
152 TALLOC_FREE(*principal);
153 }
154 if (secblob) {
155 data_blob_free(secblob);
156 }
157 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
158 TALLOC_FREE(OIDs[j]);
159 }
160 }
161
162 asn1_free(data);
163 return ret;
164}
165
166/*
167 generate a krb5 GSS-API wrapper packet given a ticket
168*/
169DATA_BLOB spnego_gen_krb5_wrap(TALLOC_CTX *ctx, const DATA_BLOB ticket, const uint8_t tok_id[2])
170{
171 ASN1_DATA *data;
172 DATA_BLOB ret = data_blob_null;
173
174 data = asn1_init(talloc_tos());
175 if (data == NULL) {
176 return data_blob_null;
177 }
178
179 if (!asn1_push_tag(data, ASN1_APPLICATION(0))) goto err;
180 if (!asn1_write_OID(data, OID_KERBEROS5)) goto err;
181
182 if (!asn1_write(data, tok_id, 2)) goto err;
183 if (!asn1_write(data, ticket.data, ticket.length)) goto err;
184 if (!asn1_pop_tag(data)) goto err;
185
186 if (!asn1_extract_blob(data, ctx, &ret)) {
187 goto err;
188 }
189
190 asn1_free(data);
191 data = NULL;
192
193 err:
194
195 if (data != NULL) {
196 if (asn1_has_error(data)) {
197 DEBUG(1, ("Failed to build krb5 wrapper at offset %d\n",
198 (int)asn1_current_ofs(data)));
199 }
200
201 asn1_free(data);
202 }
203
204 return ret;
205}
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