xref: /dragonfly/lib/libc/rpc/auth_unix.c (revision d4ef6694)
1 /*-
2  * Copyright (c) 2009, Sun Microsystems, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  * - Redistributions of source code must retain the above copyright notice,
8  *   this list of conditions and the following disclaimer.
9  * - Redistributions in binary form must reproduce the above copyright notice,
10  *   this list of conditions and the following disclaimer in the documentation
11  *   and/or other materials provided with the distribution.
12  * - Neither the name of Sun Microsystems, Inc. nor the names of its
13  *   contributors may be used to endorse or promote products derived
14  *   from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  *
28  * @(#)auth_unix.c	1.19 87/08/11 Copyr 1984 Sun Micro
29  * @(#)auth_unix.c	2.2 88/08/01 4.0 RPCSRC
30  * $NetBSD: auth_unix.c,v 1.18 2000/07/06 03:03:30 christos Exp $
31  * $FreeBSD: src/lib/libc/rpc/auth_unix.c,v 1.18 2007/06/14 20:07:35 harti Exp $
32  */
33 
34 /*
35  * auth_unix.c, Implements UNIX style authentication parameters.
36  *
37  * Copyright (C) 1984, Sun Microsystems, Inc.
38  *
39  * The system is very weak.  The client uses no encryption for it's
40  * credentials and only sends null verifiers.  The server sends backs
41  * null verifiers or optionally a verifier that suggests a new short hand
42  * for the credentials.
43  *
44  */
45 
46 #include "namespace.h"
47 #include "reentrant.h"
48 #include <sys/param.h>
49 
50 #include <assert.h>
51 #include <err.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <unistd.h>
55 #include <string.h>
56 
57 #include <rpc/types.h>
58 #include <rpc/xdr.h>
59 #include <rpc/auth.h>
60 #include <rpc/auth_unix.h>
61 #include "un-namespace.h"
62 #include "mt_misc.h"
63 
64 /* auth_unix.c */
65 static void		 authunix_destroy(AUTH *);
66 static bool_t		 authunix_marshal(AUTH *, XDR *);
67 static void		 authunix_nextverf(AUTH *);
68 static struct auth_ops	*authunix_ops(void);
69 static bool_t		 authunix_refresh(AUTH *, void *);
70 static bool_t		 authunix_validate(AUTH *, struct opaque_auth *);
71 static void		 marshal_new_auth(AUTH *);
72 
73 /*
74  * This struct is pointed to by the ah_private field of an auth_handle.
75  */
76 struct audata {
77 	struct opaque_auth	au_origcred;	/* original credentials */
78 	struct opaque_auth	au_shcred;	/* short hand cred */
79 	u_long			au_shfaults;	/* short hand cache faults */
80 	char			au_marshed[MAX_AUTH_BYTES];
81 	u_int			au_mpos;	/* xdr pos at end of marshed */
82 };
83 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
84 
85 /*
86  * Create a unix style authenticator.
87  * Returns an auth handle with the given stuff in it.
88  */
89 AUTH *
90 authunix_create(char *machname, int uid, int gid, int len, int *aup_gids)
91 {
92 	struct authunix_parms aup;
93 	char mymem[MAX_AUTH_BYTES];
94 	struct timeval now;
95 	XDR xdrs;
96 	AUTH *auth;
97 	struct audata *au;
98 
99 	/*
100 	 * Allocate and set up auth handle
101 	 */
102 	au = NULL;
103 	auth = mem_alloc(sizeof(*auth));
104 #ifndef _KERNEL
105 	if (auth == NULL) {
106 		warnx("authunix_create: out of memory");
107 		goto cleanup_authunix_create;
108 	}
109 #endif
110 	au = mem_alloc(sizeof(*au));
111 #ifndef _KERNEL
112 	if (au == NULL) {
113 		warnx("authunix_create: out of memory");
114 		goto cleanup_authunix_create;
115 	}
116 #endif
117 	auth->ah_ops = authunix_ops();
118 	auth->ah_private = (caddr_t)au;
119 	auth->ah_verf = au->au_shcred = _null_auth;
120 	au->au_shfaults = 0;
121 	au->au_origcred.oa_base = NULL;
122 
123 	/*
124 	 * fill in param struct from the given params
125 	 */
126 	gettimeofday(&now, NULL);
127 	aup.aup_time = now.tv_sec;
128 	aup.aup_machname = machname;
129 	aup.aup_uid = uid;
130 	aup.aup_gid = gid;
131 	aup.aup_len = (u_int)len;
132 	aup.aup_gids = aup_gids;
133 
134 	/*
135 	 * Serialize the parameters into origcred
136 	 */
137 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
138 	if (! xdr_authunix_parms(&xdrs, &aup))
139 		abort();
140 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
141 	au->au_origcred.oa_flavor = AUTH_UNIX;
142 #ifdef _KERNEL
143 	au->au_origcred.oa_base = mem_alloc((u_int) len);
144 #else
145 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
146 		warnx("authunix_create: out of memory");
147 		goto cleanup_authunix_create;
148 	}
149 #endif
150 	memmove(au->au_origcred.oa_base, mymem, (size_t)len);
151 
152 	/*
153 	 * set auth handle to reflect new cred.
154 	 */
155 	auth->ah_cred = au->au_origcred;
156 	marshal_new_auth(auth);
157 	return (auth);
158 #ifndef _KERNEL
159  cleanup_authunix_create:
160 	if (auth)
161 		mem_free(auth, sizeof(*auth));
162 	if (au) {
163 		if (au->au_origcred.oa_base)
164 			mem_free(au->au_origcred.oa_base, (u_int)len);
165 		mem_free(au, sizeof(*au));
166 	}
167 	return (NULL);
168 #endif
169 }
170 
171 /*
172  * Returns an auth handle with parameters determined by doing lots of
173  * syscalls.
174  */
175 AUTH *
176 authunix_create_default(void)
177 {
178 	int len;
179 	char machname[MAXHOSTNAMELEN + 1];
180 	uid_t uid;
181 	gid_t gid;
182 	gid_t gids[NGROUPS_MAX];
183 
184 	if (gethostname(machname, sizeof machname) == -1)
185 		abort();
186 	machname[sizeof(machname) - 1] = 0;
187 	uid = geteuid();
188 	gid = getegid();
189 	if ((len = getgroups(NGROUPS_MAX, gids)) < 0)
190 		abort();
191 	if (len > NGRPS)
192 		len = NGRPS;
193 	/* XXX: interface problem; those should all have been unsigned */
194 	return (authunix_create(machname, (int)uid, (int)gid, len,
195 	    (int *)gids));
196 }
197 
198 /*
199  * authunix operations
200  */
201 
202 /* ARGSUSED */
203 static void
204 authunix_nextverf(AUTH *auth __unused)
205 {
206 	/* no action necessary */
207 }
208 
209 static bool_t
210 authunix_marshal(AUTH *auth, XDR *xdrs)
211 {
212 	struct audata *au;
213 
214 	assert(auth != NULL);
215 	assert(xdrs != NULL);
216 
217 	au = AUTH_PRIVATE(auth);
218 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
219 }
220 
221 static bool_t
222 authunix_validate(AUTH *auth, struct opaque_auth *verf)
223 {
224 	struct audata *au;
225 	XDR xdrs;
226 
227 	assert(auth != NULL);
228 	assert(verf != NULL);
229 
230 	if (verf->oa_flavor == AUTH_SHORT) {
231 		au = AUTH_PRIVATE(auth);
232 		xdrmem_create(&xdrs, verf->oa_base, verf->oa_length,
233 		    XDR_DECODE);
234 
235 		if (au->au_shcred.oa_base != NULL) {
236 			mem_free(au->au_shcred.oa_base,
237 			    au->au_shcred.oa_length);
238 			au->au_shcred.oa_base = NULL;
239 		}
240 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
241 			auth->ah_cred = au->au_shcred;
242 		} else {
243 			xdrs.x_op = XDR_FREE;
244 			xdr_opaque_auth(&xdrs, &au->au_shcred);
245 			au->au_shcred.oa_base = NULL;
246 			auth->ah_cred = au->au_origcred;
247 		}
248 		marshal_new_auth(auth);
249 	}
250 	return (TRUE);
251 }
252 
253 static bool_t
254 authunix_refresh(AUTH *auth, void *dummy __unused)
255 {
256 	struct audata *au = AUTH_PRIVATE(auth);
257 	struct authunix_parms aup;
258 	struct timeval now;
259 	XDR xdrs;
260 	int stat;
261 
262 	assert(auth != NULL);
263 
264 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
265 		/* there is no hope.  Punt */
266 		return (FALSE);
267 	}
268 	au->au_shfaults ++;
269 
270 	/* first deserialize the creds back into a struct authunix_parms */
271 	aup.aup_machname = NULL;
272 	aup.aup_gids = NULL;
273 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
274 	    au->au_origcred.oa_length, XDR_DECODE);
275 	stat = xdr_authunix_parms(&xdrs, &aup);
276 	if (! stat)
277 		goto done;
278 
279 	/* update the time and serialize in place */
280 	gettimeofday(&now, NULL);
281 	aup.aup_time = now.tv_sec;
282 	xdrs.x_op = XDR_ENCODE;
283 	XDR_SETPOS(&xdrs, 0);
284 	stat = xdr_authunix_parms(&xdrs, &aup);
285 	if (! stat)
286 		goto done;
287 	auth->ah_cred = au->au_origcred;
288 	marshal_new_auth(auth);
289 done:
290 	/* free the struct authunix_parms created by deserializing */
291 	xdrs.x_op = XDR_FREE;
292 	xdr_authunix_parms(&xdrs, &aup);
293 	XDR_DESTROY(&xdrs);
294 	return (stat);
295 }
296 
297 static void
298 authunix_destroy(AUTH *auth)
299 {
300 	struct audata *au;
301 
302 	assert(auth != NULL);
303 
304 	au = AUTH_PRIVATE(auth);
305 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
306 
307 	if (au->au_shcred.oa_base != NULL)
308 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
309 
310 	mem_free(auth->ah_private, sizeof(struct audata));
311 
312 	if (auth->ah_verf.oa_base != NULL)
313 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
314 
315 	mem_free(auth, sizeof(*auth));
316 }
317 
318 /*
319  * Marshals (pre-serializes) an auth struct.
320  * sets private data, au_marshed and au_mpos
321  */
322 static void
323 marshal_new_auth(AUTH *auth)
324 {
325 	XDR	xdr_stream;
326 	XDR	*xdrs = &xdr_stream;
327 	struct audata *au;
328 
329 	assert(auth != NULL);
330 
331 	au = AUTH_PRIVATE(auth);
332 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
333 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
334 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
335 		warnx("auth_none.c - Fatal marshalling problem");
336 	else
337 		au->au_mpos = XDR_GETPOS(xdrs);
338 	XDR_DESTROY(xdrs);
339 }
340 
341 static struct auth_ops *
342 authunix_ops(void)
343 {
344 	static struct auth_ops ops;
345 
346 	/* VARIABLES PROTECTED BY ops_lock: ops */
347 
348 	mutex_lock(&ops_lock);
349 	if (ops.ah_nextverf == NULL) {
350 		ops.ah_nextverf = authunix_nextverf;
351 		ops.ah_marshal = authunix_marshal;
352 		ops.ah_validate = authunix_validate;
353 		ops.ah_refresh = authunix_refresh;
354 		ops.ah_destroy = authunix_destroy;
355 	}
356 	mutex_unlock(&ops_lock);
357 	return (&ops);
358 }
359