1 /* $NetBSD: auth_unix.c,v 1.28 2024/01/23 17:24:38 christos Exp $ */
2
3 /*
4 * Copyright (c) 2010, Oracle America, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met:
9 *
10 * * Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * * Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following
14 * disclaimer in the documentation and/or other materials
15 * provided with the distribution.
16 * * Neither the name of the "Oracle America, Inc." nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <sys/cdefs.h>
35 #if defined(LIBC_SCCS) && !defined(lint)
36 #if 0
37 static char *sccsid = "@(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro";
38 static char *sccsid = "@(#)auth_unix.c 2.2 88/08/01 4.0 RPCSRC";
39 #else
40 __RCSID("$NetBSD: auth_unix.c,v 1.28 2024/01/23 17:24:38 christos Exp $");
41 #endif
42 #endif
43
44 /*
45 * auth_unix.c, Implements UNIX style authentication parameters.
46 *
47 * Copyright (C) 1984, Sun Microsystems, Inc.
48 *
49 * The system is very weak. The client uses no encryption for its
50 * credentials and only sends null verifiers. The server sends backs
51 * null verifiers or optionally a verifier that suggests a new short hand
52 * for the credentials.
53 *
54 */
55
56 #include "namespace.h"
57 #include "reentrant.h"
58 #include <sys/param.h>
59
60 #include <assert.h>
61 #include <err.h>
62 #include <stdio.h>
63 #include <stdlib.h>
64 #include <string.h>
65 #include <unistd.h>
66
67 #include <rpc/types.h>
68 #include <rpc/xdr.h>
69 #include <rpc/rpc.h>
70 #include <rpc/auth.h>
71 #include <rpc/auth_unix.h>
72
73 #include "rpc_internal.h"
74
75 #ifdef __weak_alias
76 __weak_alias(authunix_create,_authunix_create)
77 __weak_alias(authunix_create_default,_authunix_create_default)
78 #endif
79
80
81 /* auth_unix.c */
82 static void authunix_nextverf(AUTH *);
83 static bool_t authunix_marshal(AUTH *, XDR *);
84 static bool_t authunix_validate(AUTH *, struct opaque_auth *);
85 static bool_t authunix_refresh(AUTH *);
86 static void authunix_destroy(AUTH *);
87 static void marshal_new_auth(AUTH *);
88 static const struct auth_ops *authunix_ops(void);
89
90 /*
91 * This struct is pointed to by the ah_private field of an auth_handle.
92 */
93 struct audata {
94 struct opaque_auth au_origcred; /* original credentials */
95 struct opaque_auth au_shcred; /* short hand cred */
96 u_long au_shfaults; /* short hand cache faults */
97 char au_marshed[MAX_AUTH_BYTES];
98 u_int au_mpos; /* xdr pos at end of marshed */
99 };
100 #define AUTH_PRIVATE(auth) ((struct audata *)auth->ah_private)
101
102 /*
103 * Create a unix style authenticator.
104 * Returns an auth handle with the given stuff in it.
105 */
106 AUTH *
authunix_create(char * machname,int uid,int gid,int len,int * aup_gids)107 authunix_create(char *machname, int uid, int gid, int len, int *aup_gids)
108 {
109 struct authunix_parms aup;
110 char mymem[MAX_AUTH_BYTES];
111 struct timeval now;
112 XDR xdrs;
113 AUTH *auth;
114 struct audata *au;
115
116 /*
117 * Allocate and set up auth handle
118 */
119 au = NULL;
120 auth = mem_alloc(sizeof(*auth));
121 #ifndef KERNEL
122 if (auth == NULL) {
123 warn("%s: out of memory", __func__);
124 goto cleanup_authunix_create;
125 }
126 #endif
127 au = mem_alloc(sizeof(*au));
128 #ifndef KERNEL
129 if (au == NULL) {
130 warn("%s: out of memory", __func__);
131 goto cleanup_authunix_create;
132 }
133 #endif
134 auth->ah_ops = authunix_ops();
135 auth->ah_private = au;
136 auth->ah_verf = au->au_shcred = _null_auth;
137 au->au_shfaults = 0;
138 au->au_origcred.oa_base = NULL;
139
140 /*
141 * fill in param struct from the given params
142 */
143 (void)gettimeofday(&now, NULL);
144 aup.aup_time = (u_long)now.tv_sec; /* XXX: truncate on 32 bit */
145 aup.aup_machname = machname;
146 aup.aup_uid = uid;
147 aup.aup_gid = gid;
148 aup.aup_len = (u_int)len;
149 aup.aup_gids = aup_gids;
150
151 /*
152 * Serialize the parameters into origcred
153 */
154 xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
155 if (! xdr_authunix_parms(&xdrs, &aup))
156 abort();
157 au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
158 au->au_origcred.oa_flavor = AUTH_UNIX;
159 #ifdef KERNEL
160 au->au_origcred.oa_base = mem_alloc((size_t)len);
161 #else
162 if ((au->au_origcred.oa_base = mem_alloc((size_t)len)) == NULL) {
163 warn("%s: out of memory", __func__);
164 goto cleanup_authunix_create;
165 }
166 #endif
167 memmove(au->au_origcred.oa_base, mymem, (size_t)len);
168
169 /*
170 * set auth handle to reflect new cred.
171 */
172 auth->ah_cred = au->au_origcred;
173 marshal_new_auth(auth);
174 return (auth);
175 #ifndef KERNEL
176 cleanup_authunix_create:
177 if (auth)
178 mem_free(auth, sizeof(*auth));
179 if (au) {
180 if (au->au_origcred.oa_base)
181 mem_free(au->au_origcred.oa_base, (u_int)len);
182 mem_free(au, sizeof(*au));
183 }
184 return (NULL);
185 #endif
186 }
187
188 /*
189 * Some servers will refuse mounts if the group list is larger
190 * than it expects (like 8). This allows the application to set
191 * the maximum size of the group list that will be sent.
192 */
193 static int maxgrplist = NGROUPS;
194
195 void
set_rpc_maxgrouplist(int num)196 set_rpc_maxgrouplist(int num)
197 {
198 if (num < NGROUPS)
199 maxgrplist = num;
200 }
201
202 /*
203 * Returns an auth handle with parameters determined by doing lots of
204 * syscalls.
205 */
206 AUTH *
authunix_create_default(void)207 authunix_create_default(void)
208 {
209 int len;
210 char machname[MAXHOSTNAMELEN + 1];
211 uid_t uid;
212 gid_t gid;
213 gid_t gids[NGRPS];
214
215 if (gethostname(machname, sizeof machname) == -1)
216 abort();
217 machname[sizeof(machname) - 1] = 0;
218 uid = geteuid();
219 gid = getegid();
220 if ((len = getgroups(NGRPS, gids)) < 0)
221 abort();
222 if (len > maxgrplist)
223 len = maxgrplist;
224 /* XXX: interface problem; those should all have been unsigned */
225 return (authunix_create(machname, (int)uid, (int)gid, len,
226 (int *)gids));
227 }
228
229 /*
230 * authunix operations
231 */
232
233 /* ARGSUSED */
234 static void
authunix_nextverf(AUTH * auth)235 authunix_nextverf(AUTH *auth)
236 {
237 /* no action necessary */
238 }
239
240 static bool_t
authunix_marshal(AUTH * auth,XDR * xdrs)241 authunix_marshal(AUTH *auth, XDR *xdrs)
242 {
243 struct audata *au;
244
245 _DIAGASSERT(auth != NULL);
246 _DIAGASSERT(xdrs != NULL);
247
248 au = AUTH_PRIVATE(auth);
249 return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
250 }
251
252 static bool_t
authunix_validate(AUTH * auth,struct opaque_auth * verf)253 authunix_validate(AUTH *auth, struct opaque_auth *verf)
254 {
255 struct audata *au;
256 XDR xdrs;
257
258 _DIAGASSERT(auth != NULL);
259 _DIAGASSERT(verf != NULL);
260
261 if (verf->oa_flavor == AUTH_SHORT) {
262 au = AUTH_PRIVATE(auth);
263 xdrmem_create(&xdrs, verf->oa_base, verf->oa_length,
264 XDR_DECODE);
265
266 if (au->au_shcred.oa_base != NULL) {
267 mem_free(au->au_shcred.oa_base,
268 au->au_shcred.oa_length);
269 au->au_shcred.oa_base = NULL;
270 }
271 if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
272 auth->ah_cred = au->au_shcred;
273 } else {
274 xdrs.x_op = XDR_FREE;
275 (void)xdr_opaque_auth(&xdrs, &au->au_shcred);
276 au->au_shcred.oa_base = NULL;
277 auth->ah_cred = au->au_origcred;
278 }
279 marshal_new_auth(auth);
280 }
281 return (TRUE);
282 }
283
284 static bool_t
authunix_refresh(AUTH * auth)285 authunix_refresh(AUTH *auth)
286 {
287 struct audata *au = AUTH_PRIVATE(auth);
288 struct authunix_parms aup;
289 struct timeval now;
290 XDR xdrs;
291 int stat;
292
293 _DIAGASSERT(auth != NULL);
294
295 if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
296 /* there is no hope. Punt */
297 return (FALSE);
298 }
299 au->au_shfaults++;
300
301 /* first deserialize the creds back into a struct authunix_parms */
302 aup.aup_machname = NULL;
303 aup.aup_gids = NULL;
304 xdrmem_create(&xdrs, au->au_origcred.oa_base,
305 au->au_origcred.oa_length, XDR_DECODE);
306 stat = xdr_authunix_parms(&xdrs, &aup);
307 if (! stat)
308 goto done;
309
310 /* update the time and serialize in place */
311 (void)gettimeofday(&now, NULL);
312 aup.aup_time = (u_long)now.tv_sec; /* XXX: truncate on 32 bit */
313 xdrs.x_op = XDR_ENCODE;
314 XDR_SETPOS(&xdrs, 0);
315 stat = xdr_authunix_parms(&xdrs, &aup);
316 if (! stat)
317 goto done;
318 auth->ah_cred = au->au_origcred;
319 marshal_new_auth(auth);
320 done:
321 /* free the struct authunix_parms created by deserializing */
322 xdrs.x_op = XDR_FREE;
323 (void)xdr_authunix_parms(&xdrs, &aup);
324 XDR_DESTROY(&xdrs);
325 return (stat);
326 }
327
328 static void
authunix_destroy(AUTH * auth)329 authunix_destroy(AUTH *auth)
330 {
331 struct audata *au;
332
333 _DIAGASSERT(auth != NULL);
334
335 au = AUTH_PRIVATE(auth);
336 mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
337
338 if (au->au_shcred.oa_base != NULL)
339 mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
340
341 mem_free(auth->ah_private, sizeof(struct audata));
342
343 if (auth->ah_verf.oa_base != NULL)
344 mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
345
346 mem_free(auth, sizeof(*auth));
347 }
348
349 /*
350 * Marshals (pre-serializes) an auth struct.
351 * sets private data, au_marshed and au_mpos
352 */
353 static void
marshal_new_auth(AUTH * auth)354 marshal_new_auth(AUTH *auth)
355 {
356 XDR xdr_stream;
357 XDR *xdrs = &xdr_stream;
358 struct audata *au;
359
360 _DIAGASSERT(auth != NULL);
361
362 au = AUTH_PRIVATE(auth);
363 xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
364 if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
365 (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
366 warnx("%s: Fatal marshalling problem", __func__);
367 else
368 au->au_mpos = XDR_GETPOS(xdrs);
369 XDR_DESTROY(xdrs);
370 }
371
372 static const struct auth_ops *
authunix_ops(void)373 authunix_ops(void)
374 {
375 static struct auth_ops ops;
376
377 /* VARIABLES PROTECTED BY ops_lock: ops */
378
379 mutex_lock(&ops_lock);
380 if (ops.ah_nextverf == NULL) {
381 ops.ah_nextverf = authunix_nextverf;
382 ops.ah_marshal = authunix_marshal;
383 ops.ah_validate = authunix_validate;
384 ops.ah_refresh = authunix_refresh;
385 ops.ah_destroy = authunix_destroy;
386 }
387 mutex_unlock(&ops_lock);
388 return (&ops);
389 }
390