source: trunk/server/source3/libaddns/dnsgss.c@ 643

Last change on this file since 643 was 596, checked in by Herwig Bauernfeind, 14 years ago

Samba 3.5: Update trunk to 3.5.8
File size: 8.7 KB
Line 
1/*
2 Public Interface file for Linux DNS client library implementation
3
4 Copyright (C) 2006 Krishna Ganugapati <krishnag@centeris.com>
5 Copyright (C) 2006 Gerald Carter <jerry@samba.org>
6
7 ** NOTE! The following LGPL license applies to the libaddns
8 ** library. This does NOT imply that all of Samba is released
9 ** under the LGPL
10
11 This library is free software; you can redistribute it and/or
12 modify it under the terms of the GNU Lesser General Public
13 License as published by the Free Software Foundation; either
14 version 2.1 of the License, or (at your option) any later version.
15
16 This library is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 Lesser General Public License for more details.
20
21 You should have received a copy of the GNU Lesser General Public
22 License along with this library; if not, see <http://www.gnu.org/licenses/>.
23*/
24
25#include "dns.h"
26#include <ctype.h>
27
28
29#ifdef HAVE_GSSAPI_SUPPORT
30
31/*********************************************************************
32*********************************************************************/
33
34#ifndef HAVE_STRUPR
35static int strupr( char *szDomainName )
36{
37 if ( !szDomainName ) {
38 return ( 0 );
39 }
40 while ( *szDomainName != '\0' ) {
41 *szDomainName = toupper( *szDomainName );
42 szDomainName++;
43 }
44 return ( 0 );
45}
46#endif
47
48#if 0
49/*********************************************************************
50*********************************************************************/
51
52static void display_status_1( const char *m, OM_uint32 code, int type )
53{
54 OM_uint32 maj_stat, min_stat;
55 gss_buffer_desc msg;
56 OM_uint32 msg_ctx;
57
58 msg_ctx = 0;
59 while ( 1 ) {
60 maj_stat = gss_display_status( &min_stat, code,
61 type, GSS_C_NULL_OID,
62 &msg_ctx, &msg );
63 fprintf( stdout, "GSS-API error %s: %s\n", m,
64 ( char * ) msg.value );
65 ( void ) gss_release_buffer( &min_stat, &msg );
66
67 if ( !msg_ctx )
68 break;
69 }
70}
71
72/*********************************************************************
73*********************************************************************/
74
75void display_status( const char *msg, OM_uint32 maj_stat, OM_uint32 min_stat )
76{
77 display_status_1( msg, maj_stat, GSS_C_GSS_CODE );
78 display_status_1( msg, min_stat, GSS_C_MECH_CODE );
79}
80#endif
81
82static DNS_ERROR dns_negotiate_gss_ctx_int( TALLOC_CTX *mem_ctx,
83 struct dns_connection *conn,
84 const char *keyname,
85 const gss_name_t target_name,
86 gss_ctx_id_t *ctx,
87 enum dns_ServerType srv_type )
88{
89 struct gss_buffer_desc_struct input_desc, *input_ptr, output_desc;
90 OM_uint32 major, minor;
91 OM_uint32 ret_flags;
92 DNS_ERROR err;
93
94 gss_OID_desc krb5_oid_desc =
95 { 9, (char *)"\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" };
96
97 *ctx = GSS_C_NO_CONTEXT;
98 input_ptr = NULL;
99
100 do {
101 major = gss_init_sec_context(
102 &minor, NULL, ctx, target_name, &krb5_oid_desc,
103 GSS_C_REPLAY_FLAG | GSS_C_MUTUAL_FLAG |
104 GSS_C_CONF_FLAG |
105 GSS_C_INTEG_FLAG,
106 0, NULL, input_ptr, NULL, &output_desc,
107 &ret_flags, NULL );
108
109 if (input_ptr != NULL) {
110 TALLOC_FREE(input_desc.value);
111 }
112
113 if (output_desc.length != 0) {
114
115 struct dns_request *req;
116 struct dns_rrec *rec;
117 struct dns_buffer *buf;
118
119 time_t t = time(NULL);
120
121 err = dns_create_query(mem_ctx, keyname, QTYPE_TKEY,
122 DNS_CLASS_IN, &req);
123 if (!ERR_DNS_IS_OK(err)) goto error;
124
125 err = dns_create_tkey_record(
126 req, keyname, "gss.microsoft.com", t,
127 t + 86400, DNS_TKEY_MODE_GSSAPI, 0,
128 output_desc.length, (uint8 *)output_desc.value,
129 &rec );
130 if (!ERR_DNS_IS_OK(err)) goto error;
131
132 /* Windows 2000 DNS is broken and requires the
133 TKEY payload in the Answer section instead
134 of the Additional seciton like Windows 2003 */
135
136 if ( srv_type == DNS_SRV_WIN2000 ) {
137 err = dns_add_rrec(req, rec, &req->num_answers,
138 &req->answers);
139 } else {
140 err = dns_add_rrec(req, rec, &req->num_additionals,
141 &req->additionals);
142 }
143
144 if (!ERR_DNS_IS_OK(err)) goto error;
145
146 err = dns_marshall_request(req, req, &buf);
147 if (!ERR_DNS_IS_OK(err)) goto error;
148
149 err = dns_send(conn, buf);
150 if (!ERR_DNS_IS_OK(err)) goto error;
151
152 TALLOC_FREE(req);
153 }
154
155 gss_release_buffer(&minor, &output_desc);
156
157 if ((major != GSS_S_COMPLETE) &&
158 (major != GSS_S_CONTINUE_NEEDED)) {
159 return ERROR_DNS_GSS_ERROR;
160 }
161
162 if (major == GSS_S_CONTINUE_NEEDED) {
163
164 struct dns_request *resp;
165 struct dns_buffer *buf;
166 struct dns_tkey_record *tkey;
167
168 err = dns_receive(mem_ctx, conn, &buf);
169 if (!ERR_DNS_IS_OK(err)) goto error;
170
171 err = dns_unmarshall_request(buf, buf, &resp);
172 if (!ERR_DNS_IS_OK(err)) goto error;
173
174 /*
175 * TODO: Compare id and keyname
176 */
177
178 if ((resp->num_additionals != 1) ||
179 (resp->num_answers == 0) ||
180 (resp->answers[0]->type != QTYPE_TKEY)) {
181 err = ERROR_DNS_INVALID_MESSAGE;
182 goto error;
183 }
184
185 err = dns_unmarshall_tkey_record(
186 mem_ctx, resp->answers[0], &tkey);
187 if (!ERR_DNS_IS_OK(err)) goto error;
188
189 input_desc.length = tkey->key_length;
190 input_desc.value = talloc_move(mem_ctx, &tkey->key);
191
192 input_ptr = &input_desc;
193
194 TALLOC_FREE(buf);
195 }
196
197 } while ( major == GSS_S_CONTINUE_NEEDED );
198
199 /* If we arrive here, we have a valid security context */
200
201 err = ERROR_DNS_SUCCESS;
202
203 error:
204
205 return err;
206}
207
208DNS_ERROR dns_negotiate_sec_ctx( const char *target_realm,
209 const char *servername,
210 const char *keyname,
211 gss_ctx_id_t *gss_ctx,
212 enum dns_ServerType srv_type )
213{
214 OM_uint32 major, minor;
215
216 char *upcaserealm, *targetname;
217 DNS_ERROR err;
218
219 gss_buffer_desc input_name;
220 struct dns_connection *conn;
221
222 gss_name_t targ_name;
223
224 gss_OID_desc nt_host_oid_desc =
225 {10, (char *)"\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x01"};
226
227 TALLOC_CTX *mem_ctx;
228
229 if (!(mem_ctx = talloc_init("dns_negotiate_sec_ctx"))) {
230 return ERROR_DNS_NO_MEMORY;
231 }
232
233 err = dns_open_connection( servername, DNS_TCP, mem_ctx, &conn );
234 if (!ERR_DNS_IS_OK(err)) goto error;
235
236 if (!(upcaserealm = talloc_strdup(mem_ctx, target_realm))) {
237 err = ERROR_DNS_NO_MEMORY;
238 goto error;
239 }
240
241 strupr(upcaserealm);
242
243 if (!(targetname = talloc_asprintf(mem_ctx, "dns/%s@%s",
244 servername, upcaserealm))) {
245 err = ERROR_DNS_NO_MEMORY;
246 goto error;
247 }
248
249 input_name.value = targetname;
250 input_name.length = strlen(targetname);
251
252 major = gss_import_name( &minor, &input_name,
253 &nt_host_oid_desc, &targ_name );
254
255 if (major) {
256 err = ERROR_DNS_GSS_ERROR;
257 goto error;
258 }
259
260 err = dns_negotiate_gss_ctx_int(mem_ctx, conn, keyname,
261 targ_name, gss_ctx, srv_type );
262
263 gss_release_name( &minor, &targ_name );
264
265 error:
266 TALLOC_FREE(mem_ctx);
267
268 return err;
269}
270
271DNS_ERROR dns_sign_update(struct dns_update_request *req,
272 gss_ctx_id_t gss_ctx,
273 const char *keyname,
274 const char *algorithmname,
275 time_t time_signed, uint16 fudge)
276{
277 struct dns_buffer *buf;
278 DNS_ERROR err;
279 struct dns_domain_name *key, *algorithm;
280 struct gss_buffer_desc_struct msg, mic;
281 OM_uint32 major, minor;
282 struct dns_rrec *rec;
283
284 err = dns_marshall_update_request(req, req, &buf);
285 if (!ERR_DNS_IS_OK(err)) return err;
286
287 err = dns_domain_name_from_string(buf, keyname, &key);
288 if (!ERR_DNS_IS_OK(err)) goto error;
289
290 err = dns_domain_name_from_string(buf, algorithmname, &algorithm);
291 if (!ERR_DNS_IS_OK(err)) goto error;
292
293 dns_marshall_domain_name(buf, key);
294 dns_marshall_uint16(buf, DNS_CLASS_ANY);
295 dns_marshall_uint32(buf, 0); /* TTL */
296 dns_marshall_domain_name(buf, algorithm);
297 dns_marshall_uint16(buf, 0); /* Time prefix for 48-bit time_t */
298 dns_marshall_uint32(buf, time_signed);
299 dns_marshall_uint16(buf, fudge);
300 dns_marshall_uint16(buf, 0); /* error */
301 dns_marshall_uint16(buf, 0); /* other len */
302
303 err = buf->error;
304 if (!ERR_DNS_IS_OK(buf->error)) goto error;
305
306 msg.value = (void *)buf->data;
307 msg.length = buf->offset;
308
309 major = gss_get_mic(&minor, gss_ctx, 0, &msg, &mic);
310 if (major != 0) {
311 err = ERROR_DNS_GSS_ERROR;
312 goto error;
313 }
314
315 if (mic.length > 0xffff) {
316 gss_release_buffer(&minor, &mic);
317 err = ERROR_DNS_GSS_ERROR;
318 goto error;
319 }
320
321 err = dns_create_tsig_record(buf, keyname, algorithmname, time_signed,
322 fudge, mic.length, (uint8 *)mic.value,
323 req->id, 0, &rec);
324 gss_release_buffer(&minor, &mic);
325 if (!ERR_DNS_IS_OK(err)) goto error;
326
327 err = dns_add_rrec(req, rec, &req->num_additionals, &req->additionals);
328
329 error:
330 TALLOC_FREE(buf);
331 return err;
332}
333
334#endif /* HAVE_GSSAPI_SUPPORT */
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