xref: /netbsd-src/lib/libc/rpc/auth_unix.c (revision 1394f01b4a9e99092957ca5d824d67219565d9b5)
1 /*	$NetBSD: auth_unix.c,v 1.5 1997/07/13 20:07:36 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 1.5 1997/07/13 20:07:36 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 <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
58 
59 #include <rpc/types.h>
60 #include <rpc/xdr.h>
61 #include <rpc/auth.h>
62 #include <rpc/auth_unix.h>
63 
64 
65 /* auth_unix.c */
66 static void authunix_nextverf __P((AUTH *));
67 static bool_t authunix_marshal __P((AUTH *, XDR *));
68 static bool_t authunix_validate __P((AUTH *, struct opaque_auth *));
69 static bool_t authunix_refresh __P((AUTH *));
70 static void authunix_destroy __P((AUTH *));
71 static void marshal_new_auth __P((AUTH *));
72 
73 /*
74  * Unix authenticator operations vector
75  */
76 static struct auth_ops auth_unix_ops = {
77 	authunix_nextverf,
78 	authunix_marshal,
79 	authunix_validate,
80 	authunix_refresh,
81 	authunix_destroy
82 };
83 
84 /*
85  * This struct is pointed to by the ah_private field of an auth_handle.
86  */
87 struct audata {
88 	struct opaque_auth	au_origcred;	/* original credentials */
89 	struct opaque_auth	au_shcred;	/* short hand cred */
90 	u_long			au_shfaults;	/* short hand cache faults */
91 	char			au_marshed[MAX_AUTH_BYTES];
92 	u_int			au_mpos;	/* xdr pos at end of marshed */
93 };
94 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
95 
96 /*
97  * Create a unix style authenticator.
98  * Returns an auth handle with the given stuff in it.
99  */
100 AUTH *
101 authunix_create(machname, uid, gid, len, aup_gids)
102 	char *machname;
103 	int uid;
104 	int gid;
105 	register int len;
106 	int *aup_gids;
107 {
108 	struct authunix_parms aup;
109 	char mymem[MAX_AUTH_BYTES];
110 	struct timeval now;
111 	XDR xdrs;
112 	register AUTH *auth;
113 	register struct audata *au;
114 
115 	/*
116 	 * Allocate and set up auth handle
117 	 */
118 	auth = (AUTH *)mem_alloc(sizeof(*auth));
119 #ifndef KERNEL
120 	if (auth == NULL) {
121 		(void)fprintf(stderr, "authunix_create: out of memory\n");
122 		return (NULL);
123 	}
124 #endif
125 	au = (struct audata *)mem_alloc(sizeof(*au));
126 #ifndef KERNEL
127 	if (au == NULL) {
128 		(void)fprintf(stderr, "authunix_create: out of memory\n");
129 		return (NULL);
130 	}
131 #endif
132 	auth->ah_ops = &auth_unix_ops;
133 	auth->ah_private = (caddr_t)au;
134 	auth->ah_verf = au->au_shcred = _null_auth;
135 	au->au_shfaults = 0;
136 
137 	/*
138 	 * fill in param struct from the given params
139 	 */
140 	(void)gettimeofday(&now,  (struct timezone *)0);
141 	aup.aup_time = now.tv_sec;
142 	aup.aup_machname = machname;
143 	aup.aup_uid = uid;
144 	aup.aup_gid = gid;
145 	aup.aup_len = (u_int)len;
146 	aup.aup_gids = aup_gids;
147 
148 	/*
149 	 * Serialize the parameters into origcred
150 	 */
151 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
152 	if (! xdr_authunix_parms(&xdrs, &aup))
153 		abort();
154 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
155 	au->au_origcred.oa_flavor = AUTH_UNIX;
156 #ifdef KERNEL
157 	au->au_origcred.oa_base = mem_alloc((u_int) len);
158 #else
159 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
160 		(void)fprintf(stderr, "authunix_create: out of memory\n");
161 		return (NULL);
162 	}
163 #endif
164 	bcopy(mymem, au->au_origcred.oa_base, (u_int)len);
165 
166 	/*
167 	 * set auth handle to reflect new cred.
168 	 */
169 	auth->ah_cred = au->au_origcred;
170 	marshal_new_auth(auth);
171 	return (auth);
172 }
173 
174 /*
175  * Returns an auth handle with parameters determined by doing lots of
176  * syscalls.
177  */
178 AUTH *
179 authunix_create_default()
180 {
181 	register int len;
182 	char machname[MAX_MACHINE_NAME + 1];
183 	register int uid;
184 	register int gid;
185 	int gids[NGRPS];
186 
187 	if (gethostname(machname, MAX_MACHINE_NAME) == -1)
188 		abort();
189 	machname[MAX_MACHINE_NAME] = 0;
190 	uid = geteuid();
191 	gid = getegid();
192 	if ((len = getgroups(NGRPS, gids)) < 0)
193 		abort();
194 	return (authunix_create(machname, uid, gid, len, gids));
195 }
196 
197 /*
198  * authunix operations
199  */
200 
201 static void
202 authunix_nextverf(auth)
203 	AUTH *auth;
204 {
205 	/* no action necessary */
206 }
207 
208 static bool_t
209 authunix_marshal(auth, xdrs)
210 	AUTH *auth;
211 	XDR *xdrs;
212 {
213 	register struct audata *au = AUTH_PRIVATE(auth);
214 
215 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
216 }
217 
218 static bool_t
219 authunix_validate(auth, verf)
220 	register AUTH *auth;
221 	struct opaque_auth *verf;
222 {
223 	register struct audata *au;
224 	XDR xdrs;
225 
226 	if (verf->oa_flavor == AUTH_SHORT) {
227 		au = AUTH_PRIVATE(auth);
228 		xdrmem_create(&xdrs, verf->oa_base, verf->oa_length, XDR_DECODE);
229 
230 		if (au->au_shcred.oa_base != NULL) {
231 			mem_free(au->au_shcred.oa_base,
232 			    au->au_shcred.oa_length);
233 			au->au_shcred.oa_base = NULL;
234 		}
235 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
236 			auth->ah_cred = au->au_shcred;
237 		} else {
238 			xdrs.x_op = XDR_FREE;
239 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
240 			au->au_shcred.oa_base = NULL;
241 			auth->ah_cred = au->au_origcred;
242 		}
243 		marshal_new_auth(auth);
244 	}
245 	return (TRUE);
246 }
247 
248 static bool_t
249 authunix_refresh(auth)
250 	register AUTH *auth;
251 {
252 	register struct audata *au = AUTH_PRIVATE(auth);
253 	struct authunix_parms aup;
254 	struct timeval now;
255 	XDR xdrs;
256 	register int stat;
257 
258 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
259 		/* there is no hope.  Punt */
260 		return (FALSE);
261 	}
262 	au->au_shfaults ++;
263 
264 	/* first deserialize the creds back into a struct authunix_parms */
265 	aup.aup_machname = NULL;
266 	aup.aup_gids = (int *)NULL;
267 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
268 	    au->au_origcred.oa_length, XDR_DECODE);
269 	stat = xdr_authunix_parms(&xdrs, &aup);
270 	if (! stat)
271 		goto done;
272 
273 	/* update the time and serialize in place */
274 	(void)gettimeofday(&now, (struct timezone *)0);
275 	aup.aup_time = now.tv_sec;
276 	xdrs.x_op = XDR_ENCODE;
277 	XDR_SETPOS(&xdrs, 0);
278 	stat = xdr_authunix_parms(&xdrs, &aup);
279 	if (! stat)
280 		goto done;
281 	auth->ah_cred = au->au_origcred;
282 	marshal_new_auth(auth);
283 done:
284 	/* free the struct authunix_parms created by deserializing */
285 	xdrs.x_op = XDR_FREE;
286 	(void)xdr_authunix_parms(&xdrs, &aup);
287 	XDR_DESTROY(&xdrs);
288 	return (stat);
289 }
290 
291 static void
292 authunix_destroy(auth)
293 	register AUTH *auth;
294 {
295 	register struct audata *au = AUTH_PRIVATE(auth);
296 
297 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
298 
299 	if (au->au_shcred.oa_base != NULL)
300 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
301 
302 	mem_free(auth->ah_private, sizeof(struct audata));
303 
304 	if (auth->ah_verf.oa_base != NULL)
305 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
306 
307 	mem_free((caddr_t)auth, sizeof(*auth));
308 }
309 
310 /*
311  * Marshals (pre-serializes) an auth struct.
312  * sets private data, au_marshed and au_mpos
313  */
314 static void
315 marshal_new_auth(auth)
316 	register AUTH *auth;
317 {
318 	XDR		xdr_stream;
319 	register XDR	*xdrs = &xdr_stream;
320 	register struct audata *au = AUTH_PRIVATE(auth);
321 
322 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
323 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
324 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) {
325 		perror("auth_none.c - Fatal marshalling problem");
326 	} else {
327 		au->au_mpos = XDR_GETPOS(xdrs);
328 	}
329 	XDR_DESTROY(xdrs);
330 }
331