xref: /netbsd-src/lib/libc/rpc/auth_unix.c (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1 /*	$NetBSD: auth_unix.c,v 1.13 1998/11/15 17:24:07 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 #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 1.13 1998/11/15 17:24:07 christos 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 	auth = (AUTH *)mem_alloc(sizeof(*auth));
129 #ifndef KERNEL
130 	if (auth == NULL) {
131 		warnx("authunix_create: out of memory");
132 		return (NULL);
133 	}
134 #endif
135 	au = (struct audata *)mem_alloc(sizeof(*au));
136 #ifndef KERNEL
137 	if (au == NULL) {
138 		warnx("authunix_create: out of memory");
139 		return (NULL);
140 	}
141 #endif
142 	auth->ah_ops = &auth_unix_ops;
143 	auth->ah_private = au;
144 	auth->ah_verf = au->au_shcred = _null_auth;
145 	au->au_shfaults = 0;
146 
147 	/*
148 	 * fill in param struct from the given params
149 	 */
150 	(void)gettimeofday(&now,  (struct timezone *)0);
151 	aup.aup_time = now.tv_sec;
152 	aup.aup_machname = machname;
153 	aup.aup_uid = uid;
154 	aup.aup_gid = gid;
155 	aup.aup_len = (u_int)len;
156 	aup.aup_gids = aup_gids;
157 
158 	/*
159 	 * Serialize the parameters into origcred
160 	 */
161 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
162 	if (! xdr_authunix_parms(&xdrs, &aup))
163 		abort();
164 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
165 	au->au_origcred.oa_flavor = AUTH_UNIX;
166 #ifdef KERNEL
167 	au->au_origcred.oa_base = mem_alloc((u_int) len);
168 #else
169 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
170 		warnx("authunix_create: out of memory");
171 		return (NULL);
172 	}
173 #endif
174 	memmove(au->au_origcred.oa_base, mymem, (size_t)len);
175 
176 	/*
177 	 * set auth handle to reflect new cred.
178 	 */
179 	auth->ah_cred = au->au_origcred;
180 	marshal_new_auth(auth);
181 	return (auth);
182 }
183 
184 /*
185  * Returns an auth handle with parameters determined by doing lots of
186  * syscalls.
187  */
188 AUTH *
189 authunix_create_default()
190 {
191 	int len;
192 	char machname[MAXHOSTNAMELEN + 1];
193 	uid_t uid;
194 	gid_t gid;
195 	gid_t gids[NGRPS];
196 
197 	if (gethostname(machname, sizeof machname) == -1)
198 		abort();
199 	machname[sizeof(machname) - 1] = 0;
200 	uid = geteuid();
201 	gid = getegid();
202 	if ((len = getgroups(NGRPS, gids)) < 0)
203 		abort();
204 	/* XXX: interface problem; those should all have been unsigned */
205 	return (authunix_create(machname, (int)uid, (int)gid, len,
206 	    (int *)gids));
207 }
208 
209 /*
210  * authunix operations
211  */
212 
213 /* ARGSUSED */
214 static void
215 authunix_nextverf(auth)
216 	AUTH *auth;
217 {
218 	/* no action necessary */
219 }
220 
221 static bool_t
222 authunix_marshal(auth, xdrs)
223 	AUTH *auth;
224 	XDR *xdrs;
225 {
226 	struct audata *au = AUTH_PRIVATE(auth);
227 
228 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
229 }
230 
231 static bool_t
232 authunix_validate(auth, verf)
233 	AUTH *auth;
234 	struct opaque_auth *verf;
235 {
236 	struct audata *au;
237 	XDR xdrs;
238 
239 	if (verf->oa_flavor == AUTH_SHORT) {
240 		au = AUTH_PRIVATE(auth);
241 		xdrmem_create(&xdrs, verf->oa_base, verf->oa_length, XDR_DECODE);
242 
243 		if (au->au_shcred.oa_base != NULL) {
244 			mem_free(au->au_shcred.oa_base,
245 			    au->au_shcred.oa_length);
246 			au->au_shcred.oa_base = NULL;
247 		}
248 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
249 			auth->ah_cred = au->au_shcred;
250 		} else {
251 			xdrs.x_op = XDR_FREE;
252 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
253 			au->au_shcred.oa_base = NULL;
254 			auth->ah_cred = au->au_origcred;
255 		}
256 		marshal_new_auth(auth);
257 	}
258 	return (TRUE);
259 }
260 
261 static bool_t
262 authunix_refresh(auth)
263 	AUTH *auth;
264 {
265 	struct audata *au = AUTH_PRIVATE(auth);
266 	struct authunix_parms aup;
267 	struct timeval now;
268 	XDR xdrs;
269 	int stat;
270 
271 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
272 		/* there is no hope.  Punt */
273 		return (FALSE);
274 	}
275 	au->au_shfaults ++;
276 
277 	/* first deserialize the creds back into a struct authunix_parms */
278 	aup.aup_machname = NULL;
279 	aup.aup_gids = (int *)NULL;
280 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
281 	    au->au_origcred.oa_length, XDR_DECODE);
282 	stat = xdr_authunix_parms(&xdrs, &aup);
283 	if (! stat)
284 		goto done;
285 
286 	/* update the time and serialize in place */
287 	(void)gettimeofday(&now, (struct timezone *)0);
288 	aup.aup_time = now.tv_sec;
289 	xdrs.x_op = XDR_ENCODE;
290 	XDR_SETPOS(&xdrs, 0);
291 	stat = xdr_authunix_parms(&xdrs, &aup);
292 	if (! stat)
293 		goto done;
294 	auth->ah_cred = au->au_origcred;
295 	marshal_new_auth(auth);
296 done:
297 	/* free the struct authunix_parms created by deserializing */
298 	xdrs.x_op = XDR_FREE;
299 	(void)xdr_authunix_parms(&xdrs, &aup);
300 	XDR_DESTROY(&xdrs);
301 	return (stat);
302 }
303 
304 static void
305 authunix_destroy(auth)
306 	AUTH *auth;
307 {
308 	struct audata *au = AUTH_PRIVATE(auth);
309 
310 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
311 
312 	if (au->au_shcred.oa_base != NULL)
313 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
314 
315 	mem_free(auth->ah_private, sizeof(struct audata));
316 
317 	if (auth->ah_verf.oa_base != NULL)
318 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
319 
320 	mem_free(auth, sizeof(*auth));
321 }
322 
323 /*
324  * Marshals (pre-serializes) an auth struct.
325  * sets private data, au_marshed and au_mpos
326  */
327 static void
328 marshal_new_auth(auth)
329 	AUTH *auth;
330 {
331 	XDR	xdr_stream;
332 	XDR	*xdrs = &xdr_stream;
333 	struct audata *au = AUTH_PRIVATE(auth);
334 
335 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
336 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
337 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
338 		warnx("auth_none.c - Fatal marshalling problem");
339 	else
340 		au->au_mpos = XDR_GETPOS(xdrs);
341 	XDR_DESTROY(xdrs);
342 }
343