xref: /netbsd-src/lib/libc/rpc/auth_unix.c (revision e4d7c2e329d54c97e0c0bd3016bbe74f550c3d5e)
1 /*	$NetBSD: auth_unix.c,v 1.16 2000/01/22 22:19:17 mycroft 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 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char *sccsid = "@(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro";
36 static char *sccsid = "@(#)auth_unix.c	2.2 88/08/01 4.0 RPCSRC";
37 #else
38 __RCSID("$NetBSD: auth_unix.c,v 1.16 2000/01/22 22:19:17 mycroft Exp $");
39 #endif
40 #endif
41 
42 /*
43  * auth_unix.c, Implements UNIX style authentication parameters.
44  *
45  * Copyright (C) 1984, Sun Microsystems, Inc.
46  *
47  * The system is very weak.  The client uses no encryption for it's
48  * credentials and only sends null verifiers.  The server sends backs
49  * null verifiers or optionally a verifier that suggests a new short hand
50  * for the credentials.
51  *
52  */
53 
54 #include "namespace.h"
55 
56 #include <sys/param.h>
57 
58 #include <assert.h>
59 #include <err.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <unistd.h>
64 
65 #include <rpc/types.h>
66 #include <rpc/xdr.h>
67 #include <rpc/auth.h>
68 #include <rpc/auth_unix.h>
69 
70 #ifdef __weak_alias
71 __weak_alias(authunix_create,_authunix_create)
72 __weak_alias(authunix_create_default,_authunix_create_default)
73 #endif
74 
75 
76 /* auth_unix.c */
77 static void authunix_nextverf __P((AUTH *));
78 static bool_t authunix_marshal __P((AUTH *, XDR *));
79 static bool_t authunix_validate __P((AUTH *, struct opaque_auth *));
80 static bool_t authunix_refresh __P((AUTH *));
81 static void authunix_destroy __P((AUTH *));
82 static void marshal_new_auth __P((AUTH *));
83 
84 /*
85  * Unix authenticator operations vector
86  */
87 static const struct auth_ops auth_unix_ops = {
88 	authunix_nextverf,
89 	authunix_marshal,
90 	authunix_validate,
91 	authunix_refresh,
92 	authunix_destroy
93 };
94 
95 /*
96  * This struct is pointed to by the ah_private field of an auth_handle.
97  */
98 struct audata {
99 	struct opaque_auth	au_origcred;	/* original credentials */
100 	struct opaque_auth	au_shcred;	/* short hand cred */
101 	u_long			au_shfaults;	/* short hand cache faults */
102 	char			au_marshed[MAX_AUTH_BYTES];
103 	u_int			au_mpos;	/* xdr pos at end of marshed */
104 };
105 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
106 
107 /*
108  * Create a unix style authenticator.
109  * Returns an auth handle with the given stuff in it.
110  */
111 AUTH *
112 authunix_create(machname, uid, gid, len, aup_gids)
113 	char *machname;
114 	int uid;
115 	int gid;
116 	int len;
117 	int *aup_gids;
118 {
119 	struct authunix_parms aup;
120 	char mymem[MAX_AUTH_BYTES];
121 	struct timeval now;
122 	XDR xdrs;
123 	AUTH *auth;
124 	struct audata *au;
125 
126 	/*
127 	 * Allocate and set up auth handle
128 	 */
129 	au = NULL;
130 	auth = (AUTH *)mem_alloc(sizeof(*auth));
131 #ifndef KERNEL
132 	if (auth == NULL) {
133 		warnx("authunix_create: out of memory");
134 		goto cleanup_authunix_create;
135 	}
136 #endif
137 	au = (struct audata *)mem_alloc(sizeof(*au));
138 #ifndef KERNEL
139 	if (au == NULL) {
140 		warnx("authunix_create: out of memory");
141 		goto cleanup_authunix_create;
142 	}
143 #endif
144 	auth->ah_ops = &auth_unix_ops;
145 	auth->ah_private = au;
146 	auth->ah_verf = au->au_shcred = _null_auth;
147 	au->au_shfaults = 0;
148 	au->au_origcred.oa_base = NULL;
149 
150 	/*
151 	 * fill in param struct from the given params
152 	 */
153 	(void)gettimeofday(&now,  (struct timezone *)0);
154 	aup.aup_time = now.tv_sec;
155 	aup.aup_machname = machname;
156 	aup.aup_uid = uid;
157 	aup.aup_gid = gid;
158 	aup.aup_len = (u_int)len;
159 	aup.aup_gids = aup_gids;
160 
161 	/*
162 	 * Serialize the parameters into origcred
163 	 */
164 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
165 	if (! xdr_authunix_parms(&xdrs, &aup))
166 		abort();
167 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
168 	au->au_origcred.oa_flavor = AUTH_UNIX;
169 #ifdef KERNEL
170 	au->au_origcred.oa_base = mem_alloc((u_int) len);
171 #else
172 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
173 		warnx("authunix_create: out of memory");
174 		goto cleanup_authunix_create;
175 	}
176 #endif
177 	memmove(au->au_origcred.oa_base, mymem, (size_t)len);
178 
179 	/*
180 	 * set auth handle to reflect new cred.
181 	 */
182 	auth->ah_cred = au->au_origcred;
183 	marshal_new_auth(auth);
184 	return (auth);
185 #ifndef KERNEL
186  cleanup_authunix_create:
187 	if (auth)
188 		mem_free(auth, sizeof(*auth));
189 	if (au) {
190 		if (au->au_origcred.oa_base)
191 			mem_free(au->au_origcred.oa_base, (u_int)len);
192 		mem_free(au, sizeof(*au));
193 	}
194 	return (NULL);
195 #endif
196 }
197 
198 /*
199  * Returns an auth handle with parameters determined by doing lots of
200  * syscalls.
201  */
202 AUTH *
203 authunix_create_default()
204 {
205 	int len;
206 	char machname[MAXHOSTNAMELEN + 1];
207 	uid_t uid;
208 	gid_t gid;
209 	gid_t gids[NGRPS];
210 
211 	if (gethostname(machname, sizeof machname) == -1)
212 		abort();
213 	machname[sizeof(machname) - 1] = 0;
214 	uid = geteuid();
215 	gid = getegid();
216 	if ((len = getgroups(NGRPS, gids)) < 0)
217 		abort();
218 	/* XXX: interface problem; those should all have been unsigned */
219 	return (authunix_create(machname, (int)uid, (int)gid, len,
220 	    (int *)gids));
221 }
222 
223 /*
224  * authunix operations
225  */
226 
227 /* ARGSUSED */
228 static void
229 authunix_nextverf(auth)
230 	AUTH *auth;
231 {
232 	/* no action necessary */
233 }
234 
235 static bool_t
236 authunix_marshal(auth, xdrs)
237 	AUTH *auth;
238 	XDR *xdrs;
239 {
240 	struct audata *au;
241 
242 	_DIAGASSERT(auth != NULL);
243 	_DIAGASSERT(xdrs != NULL);
244 
245 	au = AUTH_PRIVATE(auth);
246 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
247 }
248 
249 static bool_t
250 authunix_validate(auth, verf)
251 	AUTH *auth;
252 	struct opaque_auth *verf;
253 {
254 	struct audata *au;
255 	XDR xdrs;
256 
257 	_DIAGASSERT(auth != NULL);
258 	_DIAGASSERT(verf != NULL);
259 
260 	if (verf->oa_flavor == AUTH_SHORT) {
261 		au = AUTH_PRIVATE(auth);
262 		xdrmem_create(&xdrs, verf->oa_base, verf->oa_length,
263 		    XDR_DECODE);
264 
265 		if (au->au_shcred.oa_base != NULL) {
266 			mem_free(au->au_shcred.oa_base,
267 			    au->au_shcred.oa_length);
268 			au->au_shcred.oa_base = NULL;
269 		}
270 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
271 			auth->ah_cred = au->au_shcred;
272 		} else {
273 			xdrs.x_op = XDR_FREE;
274 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
275 			au->au_shcred.oa_base = NULL;
276 			auth->ah_cred = au->au_origcred;
277 		}
278 		marshal_new_auth(auth);
279 	}
280 	return (TRUE);
281 }
282 
283 static bool_t
284 authunix_refresh(auth)
285 	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 = (int *)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, (struct timezone *)0);
312 	aup.aup_time = now.tv_sec;
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
329 authunix_destroy(auth)
330 	AUTH *auth;
331 {
332 	struct audata *au;
333 
334 	_DIAGASSERT(auth != NULL);
335 
336 	au = AUTH_PRIVATE(auth);
337 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
338 
339 	if (au->au_shcred.oa_base != NULL)
340 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
341 
342 	mem_free(auth->ah_private, sizeof(struct audata));
343 
344 	if (auth->ah_verf.oa_base != NULL)
345 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
346 
347 	mem_free(auth, sizeof(*auth));
348 }
349 
350 /*
351  * Marshals (pre-serializes) an auth struct.
352  * sets private data, au_marshed and au_mpos
353  */
354 static void
355 marshal_new_auth(auth)
356 	AUTH *auth;
357 {
358 	XDR	xdr_stream;
359 	XDR	*xdrs = &xdr_stream;
360 	struct audata *au;
361 
362 	_DIAGASSERT(auth != NULL);
363 
364 	au = AUTH_PRIVATE(auth);
365 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
366 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
367 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
368 		warnx("auth_none.c - Fatal marshalling problem");
369 	else
370 		au->au_mpos = XDR_GETPOS(xdrs);
371 	XDR_DESTROY(xdrs);
372 }
373