xref: /netbsd-src/lib/libc/rpc/auth_unix.c (revision bada23909e740596d0a3785a73bd3583a9807fb8)
1 /*	$NetBSD: auth_unix.c,v 1.14 1999/01/20 11:37:34 lukem 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 1.14 1999/01/20 11:37:34 lukem 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 <err.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <unistd.h>
63 
64 #include <rpc/types.h>
65 #include <rpc/xdr.h>
66 #include <rpc/auth.h>
67 #include <rpc/auth_unix.h>
68 
69 #ifdef __weak_alias
70 __weak_alias(authunix_create,_authunix_create);
71 __weak_alias(authunix_create_default,_authunix_create_default);
72 #endif
73 
74 
75 /* auth_unix.c */
76 static void authunix_nextverf __P((AUTH *));
77 static bool_t authunix_marshal __P((AUTH *, XDR *));
78 static bool_t authunix_validate __P((AUTH *, struct opaque_auth *));
79 static bool_t authunix_refresh __P((AUTH *));
80 static void authunix_destroy __P((AUTH *));
81 static void marshal_new_auth __P((AUTH *));
82 
83 /*
84  * Unix authenticator operations vector
85  */
86 static const struct auth_ops auth_unix_ops = {
87 	authunix_nextverf,
88 	authunix_marshal,
89 	authunix_validate,
90 	authunix_refresh,
91 	authunix_destroy
92 };
93 
94 /*
95  * This struct is pointed to by the ah_private field of an auth_handle.
96  */
97 struct audata {
98 	struct opaque_auth	au_origcred;	/* original credentials */
99 	struct opaque_auth	au_shcred;	/* short hand cred */
100 	u_long			au_shfaults;	/* short hand cache faults */
101 	char			au_marshed[MAX_AUTH_BYTES];
102 	u_int			au_mpos;	/* xdr pos at end of marshed */
103 };
104 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
105 
106 /*
107  * Create a unix style authenticator.
108  * Returns an auth handle with the given stuff in it.
109  */
110 AUTH *
111 authunix_create(machname, uid, gid, len, aup_gids)
112 	char *machname;
113 	int uid;
114 	int gid;
115 	int len;
116 	int *aup_gids;
117 {
118 	struct authunix_parms aup;
119 	char mymem[MAX_AUTH_BYTES];
120 	struct timeval now;
121 	XDR xdrs;
122 	AUTH *auth;
123 	struct audata *au;
124 
125 	/*
126 	 * Allocate and set up auth handle
127 	 */
128 	au = NULL;
129 	auth = (AUTH *)mem_alloc(sizeof(*auth));
130 #ifndef KERNEL
131 	if (auth == NULL) {
132 		warnx("authunix_create: out of memory");
133 		goto cleanup_authunix_create;
134 	}
135 #endif
136 	au = (struct audata *)mem_alloc(sizeof(*au));
137 #ifndef KERNEL
138 	if (au == NULL) {
139 		warnx("authunix_create: out of memory");
140 		goto cleanup_authunix_create;
141 	}
142 #endif
143 	auth->ah_ops = &auth_unix_ops;
144 	auth->ah_private = au;
145 	auth->ah_verf = au->au_shcred = _null_auth;
146 	au->au_shfaults = 0;
147 	au->au_origcred.oa_base = NULL;
148 
149 	/*
150 	 * fill in param struct from the given params
151 	 */
152 	(void)gettimeofday(&now,  (struct timezone *)0);
153 	aup.aup_time = now.tv_sec;
154 	aup.aup_machname = machname;
155 	aup.aup_uid = uid;
156 	aup.aup_gid = gid;
157 	aup.aup_len = (u_int)len;
158 	aup.aup_gids = aup_gids;
159 
160 	/*
161 	 * Serialize the parameters into origcred
162 	 */
163 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
164 	if (! xdr_authunix_parms(&xdrs, &aup))
165 		abort();
166 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
167 	au->au_origcred.oa_flavor = AUTH_UNIX;
168 #ifdef KERNEL
169 	au->au_origcred.oa_base = mem_alloc((u_int) len);
170 #else
171 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
172 		warnx("authunix_create: out of memory");
173 		goto cleanup_authunix_create;
174 	}
175 #endif
176 	memmove(au->au_origcred.oa_base, mymem, (size_t)len);
177 
178 	/*
179 	 * set auth handle to reflect new cred.
180 	 */
181 	auth->ah_cred = au->au_origcred;
182 	marshal_new_auth(auth);
183 	return (auth);
184 #ifndef KERNEL
185  cleanup_authunix_create:
186 	if (auth)
187 		mem_free(auth, sizeof(*auth));
188 	if (au) {
189 		if (au->au_origcred.oa_base)
190 			mem_free(au->au_origcred.oa_base, (u_int)len);
191 		mem_free(au, sizeof(*au));
192 	}
193 	return (NULL);
194 #endif
195 }
196 
197 /*
198  * Returns an auth handle with parameters determined by doing lots of
199  * syscalls.
200  */
201 AUTH *
202 authunix_create_default()
203 {
204 	int len;
205 	char machname[MAXHOSTNAMELEN + 1];
206 	uid_t uid;
207 	gid_t gid;
208 	gid_t gids[NGRPS];
209 
210 	if (gethostname(machname, sizeof machname) == -1)
211 		abort();
212 	machname[sizeof(machname) - 1] = 0;
213 	uid = geteuid();
214 	gid = getegid();
215 	if ((len = getgroups(NGRPS, gids)) < 0)
216 		abort();
217 	/* XXX: interface problem; those should all have been unsigned */
218 	return (authunix_create(machname, (int)uid, (int)gid, len,
219 	    (int *)gids));
220 }
221 
222 /*
223  * authunix operations
224  */
225 
226 /* ARGSUSED */
227 static void
228 authunix_nextverf(auth)
229 	AUTH *auth;
230 {
231 	/* no action necessary */
232 }
233 
234 static bool_t
235 authunix_marshal(auth, xdrs)
236 	AUTH *auth;
237 	XDR *xdrs;
238 {
239 	struct audata *au = AUTH_PRIVATE(auth);
240 
241 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
242 }
243 
244 static bool_t
245 authunix_validate(auth, verf)
246 	AUTH *auth;
247 	struct opaque_auth *verf;
248 {
249 	struct audata *au;
250 	XDR xdrs;
251 
252 	if (verf->oa_flavor == AUTH_SHORT) {
253 		au = AUTH_PRIVATE(auth);
254 		xdrmem_create(&xdrs, verf->oa_base, verf->oa_length,
255 		    XDR_DECODE);
256 
257 		if (au->au_shcred.oa_base != NULL) {
258 			mem_free(au->au_shcred.oa_base,
259 			    au->au_shcred.oa_length);
260 			au->au_shcred.oa_base = NULL;
261 		}
262 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
263 			auth->ah_cred = au->au_shcred;
264 		} else {
265 			xdrs.x_op = XDR_FREE;
266 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
267 			au->au_shcred.oa_base = NULL;
268 			auth->ah_cred = au->au_origcred;
269 		}
270 		marshal_new_auth(auth);
271 	}
272 	return (TRUE);
273 }
274 
275 static bool_t
276 authunix_refresh(auth)
277 	AUTH *auth;
278 {
279 	struct audata *au = AUTH_PRIVATE(auth);
280 	struct authunix_parms aup;
281 	struct timeval now;
282 	XDR xdrs;
283 	int stat;
284 
285 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
286 		/* there is no hope.  Punt */
287 		return (FALSE);
288 	}
289 	au->au_shfaults ++;
290 
291 	/* first deserialize the creds back into a struct authunix_parms */
292 	aup.aup_machname = NULL;
293 	aup.aup_gids = (int *)NULL;
294 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
295 	    au->au_origcred.oa_length, XDR_DECODE);
296 	stat = xdr_authunix_parms(&xdrs, &aup);
297 	if (! stat)
298 		goto done;
299 
300 	/* update the time and serialize in place */
301 	(void)gettimeofday(&now, (struct timezone *)0);
302 	aup.aup_time = now.tv_sec;
303 	xdrs.x_op = XDR_ENCODE;
304 	XDR_SETPOS(&xdrs, 0);
305 	stat = xdr_authunix_parms(&xdrs, &aup);
306 	if (! stat)
307 		goto done;
308 	auth->ah_cred = au->au_origcred;
309 	marshal_new_auth(auth);
310 done:
311 	/* free the struct authunix_parms created by deserializing */
312 	xdrs.x_op = XDR_FREE;
313 	(void)xdr_authunix_parms(&xdrs, &aup);
314 	XDR_DESTROY(&xdrs);
315 	return (stat);
316 }
317 
318 static void
319 authunix_destroy(auth)
320 	AUTH *auth;
321 {
322 	struct audata *au = AUTH_PRIVATE(auth);
323 
324 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
325 
326 	if (au->au_shcred.oa_base != NULL)
327 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
328 
329 	mem_free(auth->ah_private, sizeof(struct audata));
330 
331 	if (auth->ah_verf.oa_base != NULL)
332 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
333 
334 	mem_free(auth, sizeof(*auth));
335 }
336 
337 /*
338  * Marshals (pre-serializes) an auth struct.
339  * sets private data, au_marshed and au_mpos
340  */
341 static void
342 marshal_new_auth(auth)
343 	AUTH *auth;
344 {
345 	XDR	xdr_stream;
346 	XDR	*xdrs = &xdr_stream;
347 	struct audata *au = AUTH_PRIVATE(auth);
348 
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