xref: /freebsd/lib/libc/rpc/auth_unix.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*	$NetBSD: auth_unix.c,v 1.18 2000/07/06 03:03:30 christos Exp $	*/
2 
3 /*
4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5  * unrestricted use provided that this legend is included on all tape
6  * media and as a part of the software program in whole or part.  Users
7  * may copy or modify Sun RPC without charge, but are not authorized
8  * to license or distribute it to anyone else except as part of a product or
9  * program developed by the user.
10  *
11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14  *
15  * Sun RPC is provided with no support and without any obligation on the
16  * part of Sun Microsystems, Inc. to assist in its use, correction,
17  * modification or enhancement.
18  *
19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21  * OR ANY PART THEREOF.
22  *
23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24  * or profits or other special, indirect and consequential damages, even if
25  * Sun has been advised of the possibility of such damages.
26  *
27  * Sun Microsystems, Inc.
28  * 2550 Garcia Avenue
29  * Mountain View, California  94043
30  */
31 
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char *sccsid2 = "@(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro";
34 static char *sccsid = "@(#)auth_unix.c	2.2 88/08/01 4.0 RPCSRC";
35 #endif
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 /*
40  * auth_unix.c, Implements UNIX style authentication parameters.
41  *
42  * Copyright (C) 1984, Sun Microsystems, Inc.
43  *
44  * The system is very weak.  The client uses no encryption for it's
45  * credentials and only sends null verifiers.  The server sends backs
46  * null verifiers or optionally a verifier that suggests a new short hand
47  * for the credentials.
48  *
49  */
50 
51 #include "namespace.h"
52 #include "reentrant.h"
53 #include <sys/param.h>
54 
55 #include <assert.h>
56 #include <err.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <unistd.h>
60 #include <string.h>
61 
62 #include <rpc/types.h>
63 #include <rpc/xdr.h>
64 #include <rpc/auth.h>
65 #include <rpc/auth_unix.h>
66 #include "un-namespace.h"
67 #include "mt_misc.h"
68 
69 /* auth_unix.c */
70 static void authunix_nextverf (AUTH *);
71 static bool_t authunix_marshal (AUTH *, XDR *);
72 static bool_t authunix_validate (AUTH *, struct opaque_auth *);
73 static bool_t authunix_refresh (AUTH *, void *);
74 static void authunix_destroy (AUTH *);
75 static void marshal_new_auth (AUTH *);
76 static struct auth_ops *authunix_ops (void);
77 
78 /*
79  * This struct is pointed to by the ah_private field of an auth_handle.
80  */
81 struct audata {
82 	struct opaque_auth	au_origcred;	/* original credentials */
83 	struct opaque_auth	au_shcred;	/* short hand cred */
84 	u_long			au_shfaults;	/* short hand cache faults */
85 	char			au_marshed[MAX_AUTH_BYTES];
86 	u_int			au_mpos;	/* xdr pos at end of marshed */
87 };
88 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
89 
90 /*
91  * Create a unix style authenticator.
92  * Returns an auth handle with the given stuff in it.
93  */
94 AUTH *
95 authunix_create(machname, uid, gid, len, aup_gids)
96 	char *machname;
97 	int uid;
98 	int gid;
99 	int len;
100 	int *aup_gids;
101 {
102 	struct authunix_parms aup;
103 	char mymem[MAX_AUTH_BYTES];
104 	struct timeval now;
105 	XDR xdrs;
106 	AUTH *auth;
107 	struct audata *au;
108 
109 	/*
110 	 * Allocate and set up auth handle
111 	 */
112 	au = NULL;
113 	auth = mem_alloc(sizeof(*auth));
114 #ifndef _KERNEL
115 	if (auth == NULL) {
116 		warnx("authunix_create: out of memory");
117 		goto cleanup_authunix_create;
118 	}
119 #endif
120 	au = mem_alloc(sizeof(*au));
121 #ifndef _KERNEL
122 	if (au == NULL) {
123 		warnx("authunix_create: out of memory");
124 		goto cleanup_authunix_create;
125 	}
126 #endif
127 	auth->ah_ops = authunix_ops();
128 	auth->ah_private = (caddr_t)au;
129 	auth->ah_verf = au->au_shcred = _null_auth;
130 	au->au_shfaults = 0;
131 	au->au_origcred.oa_base = NULL;
132 
133 	/*
134 	 * fill in param struct from the given params
135 	 */
136 	(void)gettimeofday(&now, NULL);
137 	aup.aup_time = now.tv_sec;
138 	aup.aup_machname = machname;
139 	aup.aup_uid = uid;
140 	aup.aup_gid = gid;
141 	aup.aup_len = (u_int)len;
142 	aup.aup_gids = aup_gids;
143 
144 	/*
145 	 * Serialize the parameters into origcred
146 	 */
147 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
148 	if (! xdr_authunix_parms(&xdrs, &aup))
149 		abort();
150 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
151 	au->au_origcred.oa_flavor = AUTH_UNIX;
152 #ifdef _KERNEL
153 	au->au_origcred.oa_base = mem_alloc((u_int) len);
154 #else
155 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
156 		warnx("authunix_create: out of memory");
157 		goto cleanup_authunix_create;
158 	}
159 #endif
160 	memmove(au->au_origcred.oa_base, mymem, (size_t)len);
161 
162 	/*
163 	 * set auth handle to reflect new cred.
164 	 */
165 	auth->ah_cred = au->au_origcred;
166 	marshal_new_auth(auth);
167 	return (auth);
168 #ifndef _KERNEL
169  cleanup_authunix_create:
170 	if (auth)
171 		mem_free(auth, sizeof(*auth));
172 	if (au) {
173 		if (au->au_origcred.oa_base)
174 			mem_free(au->au_origcred.oa_base, (u_int)len);
175 		mem_free(au, sizeof(*au));
176 	}
177 	return (NULL);
178 #endif
179 }
180 
181 /*
182  * Returns an auth handle with parameters determined by doing lots of
183  * syscalls.
184  */
185 AUTH *
186 authunix_create_default()
187 {
188 	int len;
189 	char machname[MAXHOSTNAMELEN + 1];
190 	uid_t uid;
191 	gid_t gid;
192 	gid_t gids[NGROUPS_MAX];
193 
194 	if (gethostname(machname, sizeof machname) == -1)
195 		abort();
196 	machname[sizeof(machname) - 1] = 0;
197 	uid = geteuid();
198 	gid = getegid();
199 	if ((len = getgroups(NGROUPS_MAX, gids)) < 0)
200 		abort();
201 	if (len > NGRPS)
202 		len = NGRPS;
203 	/* XXX: interface problem; those should all have been unsigned */
204 	return (authunix_create(machname, (int)uid, (int)gid, len,
205 	    (int *)gids));
206 }
207 
208 /*
209  * authunix operations
210  */
211 
212 /* ARGSUSED */
213 static void
214 authunix_nextverf(auth)
215 	AUTH *auth;
216 {
217 	/* no action necessary */
218 }
219 
220 static bool_t
221 authunix_marshal(auth, xdrs)
222 	AUTH *auth;
223 	XDR *xdrs;
224 {
225 	struct audata *au;
226 
227 	assert(auth != NULL);
228 	assert(xdrs != NULL);
229 
230 	au = AUTH_PRIVATE(auth);
231 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
232 }
233 
234 static bool_t
235 authunix_validate(auth, verf)
236 	AUTH *auth;
237 	struct opaque_auth *verf;
238 {
239 	struct audata *au;
240 	XDR xdrs;
241 
242 	assert(auth != NULL);
243 	assert(verf != NULL);
244 
245 	if (verf->oa_flavor == AUTH_SHORT) {
246 		au = AUTH_PRIVATE(auth);
247 		xdrmem_create(&xdrs, verf->oa_base, verf->oa_length,
248 		    XDR_DECODE);
249 
250 		if (au->au_shcred.oa_base != NULL) {
251 			mem_free(au->au_shcred.oa_base,
252 			    au->au_shcred.oa_length);
253 			au->au_shcred.oa_base = NULL;
254 		}
255 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
256 			auth->ah_cred = au->au_shcred;
257 		} else {
258 			xdrs.x_op = XDR_FREE;
259 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
260 			au->au_shcred.oa_base = NULL;
261 			auth->ah_cred = au->au_origcred;
262 		}
263 		marshal_new_auth(auth);
264 	}
265 	return (TRUE);
266 }
267 
268 static bool_t
269 authunix_refresh(AUTH *auth, void *dummy)
270 {
271 	struct audata *au = AUTH_PRIVATE(auth);
272 	struct authunix_parms aup;
273 	struct timeval now;
274 	XDR xdrs;
275 	int stat;
276 
277 	assert(auth != NULL);
278 
279 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
280 		/* there is no hope.  Punt */
281 		return (FALSE);
282 	}
283 	au->au_shfaults ++;
284 
285 	/* first deserialize the creds back into a struct authunix_parms */
286 	aup.aup_machname = NULL;
287 	aup.aup_gids = NULL;
288 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
289 	    au->au_origcred.oa_length, XDR_DECODE);
290 	stat = xdr_authunix_parms(&xdrs, &aup);
291 	if (! stat)
292 		goto done;
293 
294 	/* update the time and serialize in place */
295 	(void)gettimeofday(&now, NULL);
296 	aup.aup_time = now.tv_sec;
297 	xdrs.x_op = XDR_ENCODE;
298 	XDR_SETPOS(&xdrs, 0);
299 	stat = xdr_authunix_parms(&xdrs, &aup);
300 	if (! stat)
301 		goto done;
302 	auth->ah_cred = au->au_origcred;
303 	marshal_new_auth(auth);
304 done:
305 	/* free the struct authunix_parms created by deserializing */
306 	xdrs.x_op = XDR_FREE;
307 	(void)xdr_authunix_parms(&xdrs, &aup);
308 	XDR_DESTROY(&xdrs);
309 	return (stat);
310 }
311 
312 static void
313 authunix_destroy(auth)
314 	AUTH *auth;
315 {
316 	struct audata *au;
317 
318 	assert(auth != NULL);
319 
320 	au = AUTH_PRIVATE(auth);
321 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
322 
323 	if (au->au_shcred.oa_base != NULL)
324 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
325 
326 	mem_free(auth->ah_private, sizeof(struct audata));
327 
328 	if (auth->ah_verf.oa_base != NULL)
329 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
330 
331 	mem_free(auth, sizeof(*auth));
332 }
333 
334 /*
335  * Marshals (pre-serializes) an auth struct.
336  * sets private data, au_marshed and au_mpos
337  */
338 static void
339 marshal_new_auth(auth)
340 	AUTH *auth;
341 {
342 	XDR	xdr_stream;
343 	XDR	*xdrs = &xdr_stream;
344 	struct audata *au;
345 
346 	assert(auth != NULL);
347 
348 	au = AUTH_PRIVATE(auth);
349 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
350 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
351 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
352 		warnx("auth_none.c - Fatal marshalling problem");
353 	else
354 		au->au_mpos = XDR_GETPOS(xdrs);
355 	XDR_DESTROY(xdrs);
356 }
357 
358 static struct auth_ops *
359 authunix_ops()
360 {
361 	static struct auth_ops ops;
362 
363 	/* VARIABLES PROTECTED BY ops_lock: ops */
364 
365 	mutex_lock(&ops_lock);
366 	if (ops.ah_nextverf == NULL) {
367 		ops.ah_nextverf = authunix_nextverf;
368 		ops.ah_marshal = authunix_marshal;
369 		ops.ah_validate = authunix_validate;
370 		ops.ah_refresh = authunix_refresh;
371 		ops.ah_destroy = authunix_destroy;
372 	}
373 	mutex_unlock(&ops_lock);
374 	return (&ops);
375 }
376