1 /*	$NetBSD: afskrb5.c,v 1.1.1.1 2011/04/13 18:15:30 elric Exp $	*/
2 
3 /*
4  * Copyright (c) 1995-2003 Kungliga Tekniska Högskolan
5  * (Royal Institute of Technology, Stockholm, Sweden).
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * 3. Neither the name of the Institute nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "kafs_locl.h"
37 
38 struct krb5_kafs_data {
39     krb5_context context;
40     krb5_ccache id;
41     krb5_const_realm realm;
42 };
43 
44 enum {
45     KAFS_RXKAD_2B_KVNO = 213,
46     KAFS_RXKAD_K5_KVNO = 256
47 };
48 
49 static int
50 v5_to_kt(krb5_creds *cred, uid_t uid, struct kafs_token *kt, int local524)
51 {
52     int kvno, ret;
53 
54     kt->ticket = NULL;
55 
56     /* check if des key */
57     if (cred->session.keyvalue.length != 8)
58 	return EINVAL;
59 
60     if (local524) {
61 	Ticket t;
62 	unsigned char *buf;
63 	size_t buf_len;
64 	size_t len;
65 
66 	kvno = KAFS_RXKAD_2B_KVNO;
67 
68 	ret = decode_Ticket(cred->ticket.data, cred->ticket.length, &t, &len);
69 	if (ret)
70 	    return ret;
71 	if (t.tkt_vno != 5)
72 	    return -1;
73 
74 	ASN1_MALLOC_ENCODE(EncryptedData, buf, buf_len, &t.enc_part,
75 			   &len, ret);
76 	free_Ticket(&t);
77 	if (ret)
78 	    return ret;
79 	if(buf_len != len) {
80 	    free(buf);
81 	    return KRB5KRB_ERR_GENERIC;
82 	}
83 
84 	kt->ticket = buf;
85 	kt->ticket_len = buf_len;
86 
87     } else {
88 	kvno = KAFS_RXKAD_K5_KVNO;
89 	kt->ticket = malloc(cred->ticket.length);
90 	if (kt->ticket == NULL)
91 	    return ENOMEM;
92 	kt->ticket_len = cred->ticket.length;
93 	memcpy(kt->ticket, cred->ticket.data, kt->ticket_len);
94 
95 	ret = 0;
96     }
97 
98 
99     /*
100      * Build a struct ClearToken
101      */
102 
103     kt->ct.AuthHandle = kvno;
104     memcpy(kt->ct.HandShakeKey, cred->session.keyvalue.data, 8);
105     kt->ct.ViceId = uid;
106     kt->ct.BeginTimestamp = cred->times.starttime;
107     kt->ct.EndTimestamp = cred->times.endtime;
108 
109     _kafs_fixup_viceid(&kt->ct, uid);
110 
111     return 0;
112 }
113 
114 static krb5_error_code
115 v5_convert(krb5_context context, krb5_ccache id,
116 	   krb5_creds *cred, uid_t uid,
117 	   const char *cell,
118 	   struct kafs_token *kt)
119 {
120     krb5_error_code ret;
121     char *c, *val;
122 
123     c = strdup(cell);
124     if (c == NULL)
125 	return ENOMEM;
126     _kafs_foldup(c, c);
127     krb5_appdefault_string (context, "libkafs",
128 			    c,
129 			    "afs-use-524", "2b", &val);
130     free(c);
131 
132     if (strcasecmp(val, "local") == 0 ||
133 	strcasecmp(val, "2b") == 0)
134 	ret = v5_to_kt(cred, uid, kt, 1);
135     else
136 	ret = v5_to_kt(cred, uid, kt, 0);
137 
138     free(val);
139     return ret;
140 }
141 
142 
143 /*
144  *
145  */
146 
147 static int
148 get_cred(struct kafs_data *data, const char *name, const char *inst,
149 	 const char *realm, uid_t uid, struct kafs_token *kt)
150 {
151     krb5_error_code ret;
152     krb5_creds in_creds, *out_creds;
153     struct krb5_kafs_data *d = data->data;
154     int invalid;
155 
156     memset(&in_creds, 0, sizeof(in_creds));
157 
158     ret = krb5_make_principal(d->context, &in_creds.server,
159 			      realm, name, inst, NULL);
160     if(ret)
161 	return ret;
162     ret = krb5_cc_get_principal(d->context, d->id, &in_creds.client);
163     if(ret){
164 	krb5_free_principal(d->context, in_creds.server);
165 	return ret;
166     }
167 
168     in_creds.session.keytype = ETYPE_DES_CBC_CRC;
169 
170     /* check if des is disable, and in that case enable it for afs */
171     invalid = krb5_enctype_valid(d->context, in_creds.session.keytype);
172     if (invalid)
173 	krb5_enctype_enable(d->context, in_creds.session.keytype);
174 
175     ret = krb5_get_credentials(d->context, 0, d->id, &in_creds, &out_creds);
176 
177     if (invalid)
178 	krb5_enctype_disable(d->context, in_creds.session.keytype);
179 
180     krb5_free_principal(d->context, in_creds.server);
181     krb5_free_principal(d->context, in_creds.client);
182     if(ret)
183 	return ret;
184 
185     ret = v5_convert(d->context, d->id, out_creds, uid,
186 		     (inst != NULL && inst[0] != '\0') ? inst : realm, kt);
187     krb5_free_creds(d->context, out_creds);
188 
189     return ret;
190 }
191 
192 static const char *
193 get_error(struct kafs_data *data, int error)
194 {
195     struct krb5_kafs_data *d = data->data;
196     return krb5_get_error_message(d->context, error);
197 }
198 
199 static void
200 free_error(struct kafs_data *data, const char *str)
201 {
202     struct krb5_kafs_data *d = data->data;
203     krb5_free_error_message(d->context, str);
204 }
205 
206 static krb5_error_code
207 afslog_uid_int(struct kafs_data *data, const char *cell, const char *rh,
208 	       uid_t uid, const char *homedir)
209 {
210     krb5_error_code ret;
211     struct kafs_token kt;
212     krb5_principal princ;
213     const char *trealm; /* ticket realm */
214     struct krb5_kafs_data *d = data->data;
215 
216     if (cell == 0 || cell[0] == 0)
217 	return _kafs_afslog_all_local_cells (data, uid, homedir);
218 
219     ret = krb5_cc_get_principal (d->context, d->id, &princ);
220     if (ret)
221 	return ret;
222 
223     trealm = krb5_principal_get_realm (d->context, princ);
224 
225     kt.ticket = NULL;
226     ret = _kafs_get_cred(data, cell, d->realm, trealm, uid, &kt);
227     krb5_free_principal (d->context, princ);
228 
229     if(ret == 0) {
230 	ret = kafs_settoken_rxkad(cell, &kt.ct, kt.ticket, kt.ticket_len);
231 	free(kt.ticket);
232     }
233     return ret;
234 }
235 
236 static char *
237 get_realm(struct kafs_data *data, const char *host)
238 {
239     struct krb5_kafs_data *d = data->data;
240     krb5_realm *realms;
241     char *r;
242     if(krb5_get_host_realm(d->context, host, &realms))
243 	return NULL;
244     r = strdup(realms[0]);
245     krb5_free_host_realm(d->context, realms);
246     return r;
247 }
248 
249 krb5_error_code
250 krb5_afslog_uid_home(krb5_context context,
251 		     krb5_ccache id,
252 		     const char *cell,
253 		     krb5_const_realm realm,
254 		     uid_t uid,
255 		     const char *homedir)
256 {
257     struct kafs_data kd;
258     struct krb5_kafs_data d;
259     krb5_error_code ret;
260 
261     kd.name = "krb5";
262     kd.afslog_uid = afslog_uid_int;
263     kd.get_cred = get_cred;
264     kd.get_realm = get_realm;
265     kd.get_error = get_error;
266     kd.free_error = free_error;
267     kd.data = &d;
268     if (context == NULL) {
269 	ret = krb5_init_context(&d.context);
270 	if (ret)
271 	    return ret;
272     } else
273 	d.context = context;
274     if (id == NULL) {
275 	ret = krb5_cc_default(d.context, &d.id);
276 	if (ret)
277 	    goto out;
278     } else
279 	d.id = id;
280     d.realm = realm;
281     ret = afslog_uid_int(&kd, cell, 0, uid, homedir);
282     if (id == NULL)
283 	krb5_cc_close(context, d.id);
284  out:
285     if (context == NULL)
286 	krb5_free_context(d.context);
287     return ret;
288 }
289 
290 krb5_error_code
291 krb5_afslog_uid(krb5_context context,
292 		krb5_ccache id,
293 		const char *cell,
294 		krb5_const_realm realm,
295 		uid_t uid)
296 {
297     return krb5_afslog_uid_home (context, id, cell, realm, uid, NULL);
298 }
299 
300 krb5_error_code
301 krb5_afslog(krb5_context context,
302 	    krb5_ccache id,
303 	    const char *cell,
304 	    krb5_const_realm realm)
305 {
306     return krb5_afslog_uid (context, id, cell, realm, getuid());
307 }
308 
309 krb5_error_code
310 krb5_afslog_home(krb5_context context,
311 		 krb5_ccache id,
312 		 const char *cell,
313 		 krb5_const_realm realm,
314 		 const char *homedir)
315 {
316     return krb5_afslog_uid_home (context, id, cell, realm, getuid(), homedir);
317 }
318 
319 /*
320  *
321  */
322 
323 krb5_error_code
324 krb5_realm_of_cell(const char *cell, char **realm)
325 {
326     struct kafs_data kd;
327 
328     kd.name = "krb5";
329     kd.get_realm = get_realm;
330     kd.get_error = get_error;
331     kd.free_error = free_error;
332     return _kafs_realm_of_cell(&kd, cell, realm);
333 }
334 
335 /*
336  *
337  */
338 
339 int
340 kafs_settoken5(krb5_context context, const char *cell, uid_t uid,
341 	       krb5_creds *cred)
342 {
343     struct kafs_token kt;
344     int ret;
345 
346     ret = v5_convert(context, NULL, cred, uid, cell, &kt);
347     if (ret)
348 	return ret;
349 
350     ret = kafs_settoken_rxkad(cell, &kt.ct, kt.ticket, kt.ticket_len);
351 
352     free(kt.ticket);
353 
354     return ret;
355 }
356