source: trunk/samba-3.0.25pre1/source/libaddns/dnsgss.c@ 1

Last change on this file since 1 was 1, checked in by Paul Smedley, 18 years ago

Initial code import
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, write to the Free Software
23 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
24 02110-1301 USA
25*/
26
27#include "dns.h"
28#include <ctype.h>
29
30
31#ifdef HAVE_GSSAPI_SUPPORT
32
33/*********************************************************************
34*********************************************************************/
35
36static int strupr( char *szDomainName )
37{
38 if ( !szDomainName ) {
39 return ( 0 );
40 }
41 while ( *szDomainName != '\0' ) {
42 *szDomainName = toupper( *szDomainName );
43 szDomainName++;
44 }
45 return ( 0 );
46}
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_SEQUENCE_FLAG | GSS_C_CONF_FLAG |
105 GSS_C_INTEG_FLAG | GSS_C_DELEG_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 krb5_principal host_principal;
225 krb5_context krb_ctx = NULL;
226
227 gss_OID_desc nt_host_oid_desc =
228 { 10, (char *)"\052\206\110\206\367\022\001\002\002\002" };
229
230 TALLOC_CTX *mem_ctx;
231
232 if (!(mem_ctx = talloc_init("dns_negotiate_sec_ctx"))) {
233 return ERROR_DNS_NO_MEMORY;
234 }
235
236 err = dns_open_connection( servername, DNS_TCP, mem_ctx, &conn );
237 if (!ERR_DNS_IS_OK(err)) goto error;
238
239 if (!(upcaserealm = talloc_strdup(mem_ctx, target_realm))) {
240 err = ERROR_DNS_NO_MEMORY;
241 goto error;
242 }
243
244 strupr(upcaserealm);
245
246 if (!(targetname = talloc_asprintf(mem_ctx, "dns/%s@%s",
247 servername, upcaserealm))) {
248 err = ERROR_DNS_NO_MEMORY;
249 goto error;
250 }
251
252 krb5_init_context( &krb_ctx );
253 krb5_parse_name( krb_ctx, targetname, &host_principal );
254
255 input_name.value = &host_principal;
256 input_name.length = sizeof( host_principal );
257
258 major = gss_import_name( &minor, &input_name,
259 &nt_host_oid_desc, &targ_name );
260
261 if (major) {
262 krb5_free_principal( krb_ctx, host_principal );
263 krb5_free_context( krb_ctx );
264 err = ERROR_DNS_GSS_ERROR;
265 goto error;
266 }
267
268 err = dns_negotiate_gss_ctx_int(mem_ctx, conn, keyname,
269 targ_name, gss_ctx, srv_type );
270
271 gss_release_name( &minor, &targ_name );
272 krb5_free_principal( krb_ctx, host_principal );
273 krb5_free_context( krb_ctx );
274
275 error:
276 TALLOC_FREE(mem_ctx);
277
278 return err;
279}
280
281DNS_ERROR dns_sign_update(struct dns_update_request *req,
282 gss_ctx_id_t gss_ctx,
283 const char *keyname,
284 const char *algorithmname,
285 time_t time_signed, uint16 fudge)
286{
287 struct dns_buffer *buf;
288 DNS_ERROR err;
289 struct dns_domain_name *key, *algorithm;
290 struct gss_buffer_desc_struct msg, mic;
291 OM_uint32 major, minor;
292 struct dns_rrec *rec;
293
294 err = dns_marshall_update_request(req, req, &buf);
295 if (!ERR_DNS_IS_OK(err)) return err;
296
297 err = dns_domain_name_from_string(buf, keyname, &key);
298 if (!ERR_DNS_IS_OK(err)) goto error;
299
300 err = dns_domain_name_from_string(buf, algorithmname, &algorithm);
301 if (!ERR_DNS_IS_OK(err)) goto error;
302
303 dns_marshall_domain_name(buf, key);
304 dns_marshall_uint16(buf, DNS_CLASS_ANY);
305 dns_marshall_uint32(buf, 0); /* TTL */
306 dns_marshall_domain_name(buf, algorithm);
307 dns_marshall_uint16(buf, 0); /* Time prefix for 48-bit time_t */
308 dns_marshall_uint32(buf, time_signed);
309 dns_marshall_uint16(buf, fudge);
310 dns_marshall_uint16(buf, 0); /* error */
311 dns_marshall_uint16(buf, 0); /* other len */
312
313 err = buf->error;
314 if (!ERR_DNS_IS_OK(buf->error)) goto error;
315
316 msg.value = (void *)buf->data;
317 msg.length = buf->offset;
318
319 major = gss_get_mic(&minor, gss_ctx, 0, &msg, &mic);
320 if (major != 0) {
321 err = ERROR_DNS_GSS_ERROR;
322 goto error;
323 }
324
325 if (mic.length > 0xffff) {
326 gss_release_buffer(&minor, &mic);
327 err = ERROR_DNS_GSS_ERROR;
328 goto error;
329 }
330
331 err = dns_create_tsig_record(buf, keyname, algorithmname, time_signed,
332 fudge, mic.length, (uint8 *)mic.value,
333 req->id, 0, &rec);
334 gss_release_buffer(&minor, &mic);
335 if (!ERR_DNS_IS_OK(err)) goto error;
336
337 err = dns_add_rrec(req, rec, &req->num_additionals, &req->additionals);
338
339 error:
340 TALLOC_FREE(buf);
341 return err;
342}
343
344#endif /* HAVE_GSSAPI_SUPPORT */
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