xref: /netbsd-src/lib/libc/rpc/auth_unix.c (revision 037708cbd4616ccd0d7d0381ebd3964d6696c188)
1 /*	$NetBSD: auth_unix.c,v 1.4 1996/12/20 20:17:19 cgd 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 #if defined(LIBC_SCCS) && !defined(lint)
33 /*static char *sccsid = "from: @(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro";*/
34 /*static char *sccsid = "from: @(#)auth_unix.c	2.2 88/08/01 4.0 RPCSRC";*/
35 static char *rcsid = "$NetBSD: auth_unix.c,v 1.4 1996/12/20 20:17:19 cgd Exp $";
36 #endif
37 
38 /*
39  * auth_unix.c, Implements UNIX style authentication parameters.
40  *
41  * Copyright (C) 1984, Sun Microsystems, Inc.
42  *
43  * The system is very weak.  The client uses no encryption for it's
44  * credentials and only sends null verifiers.  The server sends backs
45  * null verifiers or optionally a verifier that suggests a new short hand
46  * for the credentials.
47  *
48  */
49 
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 #include <rpc/types.h>
56 #include <rpc/xdr.h>
57 #include <rpc/auth.h>
58 #include <rpc/auth_unix.h>
59 
60 /*
61  * Unix authenticator operations vector
62  */
63 static void	authunix_nextverf();
64 static bool_t	authunix_marshal();
65 static bool_t	authunix_validate();
66 static bool_t	authunix_refresh();
67 static void	authunix_destroy();
68 
69 static struct auth_ops auth_unix_ops = {
70 	authunix_nextverf,
71 	authunix_marshal,
72 	authunix_validate,
73 	authunix_refresh,
74 	authunix_destroy
75 };
76 
77 /*
78  * This struct is pointed to by the ah_private field of an auth_handle.
79  */
80 struct audata {
81 	struct opaque_auth	au_origcred;	/* original credentials */
82 	struct opaque_auth	au_shcred;	/* short hand cred */
83 	u_long			au_shfaults;	/* short hand cache faults */
84 	char			au_marshed[MAX_AUTH_BYTES];
85 	u_int			au_mpos;	/* xdr pos at end of marshed */
86 };
87 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
88 
89 static void marshal_new_auth();
90 
91 
92 /*
93  * Create a unix style authenticator.
94  * Returns an auth handle with the given stuff in it.
95  */
96 AUTH *
97 authunix_create(machname, uid, gid, len, aup_gids)
98 	char *machname;
99 	int uid;
100 	int gid;
101 	register int len;
102 	int *aup_gids;
103 {
104 	struct authunix_parms aup;
105 	char mymem[MAX_AUTH_BYTES];
106 	struct timeval now;
107 	XDR xdrs;
108 	register AUTH *auth;
109 	register struct audata *au;
110 
111 	/*
112 	 * Allocate and set up auth handle
113 	 */
114 	auth = (AUTH *)mem_alloc(sizeof(*auth));
115 #ifndef KERNEL
116 	if (auth == NULL) {
117 		(void)fprintf(stderr, "authunix_create: out of memory\n");
118 		return (NULL);
119 	}
120 #endif
121 	au = (struct audata *)mem_alloc(sizeof(*au));
122 #ifndef KERNEL
123 	if (au == NULL) {
124 		(void)fprintf(stderr, "authunix_create: out of memory\n");
125 		return (NULL);
126 	}
127 #endif
128 	auth->ah_ops = &auth_unix_ops;
129 	auth->ah_private = (caddr_t)au;
130 	auth->ah_verf = au->au_shcred = _null_auth;
131 	au->au_shfaults = 0;
132 
133 	/*
134 	 * fill in param struct from the given params
135 	 */
136 	(void)gettimeofday(&now,  (struct timezone *)0);
137 	aup.aup_time = now.tv_sec;
138 	aup.aup_machname = machname;
139 	aup.aup_uid = uid;
140 	aup.aup_gid = gid;
141 	aup.aup_len = (u_int)len;
142 	aup.aup_gids = aup_gids;
143 
144 	/*
145 	 * Serialize the parameters into origcred
146 	 */
147 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
148 	if (! xdr_authunix_parms(&xdrs, &aup))
149 		abort();
150 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
151 	au->au_origcred.oa_flavor = AUTH_UNIX;
152 #ifdef KERNEL
153 	au->au_origcred.oa_base = mem_alloc((u_int) len);
154 #else
155 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
156 		(void)fprintf(stderr, "authunix_create: out of memory\n");
157 		return (NULL);
158 	}
159 #endif
160 	bcopy(mymem, au->au_origcred.oa_base, (u_int)len);
161 
162 	/*
163 	 * set auth handle to reflect new cred.
164 	 */
165 	auth->ah_cred = au->au_origcred;
166 	marshal_new_auth(auth);
167 	return (auth);
168 }
169 
170 /*
171  * Returns an auth handle with parameters determined by doing lots of
172  * syscalls.
173  */
174 AUTH *
175 authunix_create_default()
176 {
177 	register int len;
178 	char machname[MAX_MACHINE_NAME + 1];
179 	register int uid;
180 	register int gid;
181 	int gids[NGRPS];
182 
183 	if (gethostname(machname, MAX_MACHINE_NAME) == -1)
184 		abort();
185 	machname[MAX_MACHINE_NAME] = 0;
186 	uid = geteuid();
187 	gid = getegid();
188 	if ((len = getgroups(NGRPS, gids)) < 0)
189 		abort();
190 	return (authunix_create(machname, uid, gid, len, gids));
191 }
192 
193 /*
194  * authunix operations
195  */
196 
197 static void
198 authunix_nextverf(auth)
199 	AUTH *auth;
200 {
201 	/* no action necessary */
202 }
203 
204 static bool_t
205 authunix_marshal(auth, xdrs)
206 	AUTH *auth;
207 	XDR *xdrs;
208 {
209 	register struct audata *au = AUTH_PRIVATE(auth);
210 
211 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
212 }
213 
214 static bool_t
215 authunix_validate(auth, verf)
216 	register AUTH *auth;
217 	struct opaque_auth verf;
218 {
219 	register struct audata *au;
220 	XDR xdrs;
221 
222 	if (verf.oa_flavor == AUTH_SHORT) {
223 		au = AUTH_PRIVATE(auth);
224 		xdrmem_create(&xdrs, verf.oa_base, verf.oa_length, XDR_DECODE);
225 
226 		if (au->au_shcred.oa_base != NULL) {
227 			mem_free(au->au_shcred.oa_base,
228 			    au->au_shcred.oa_length);
229 			au->au_shcred.oa_base = NULL;
230 		}
231 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
232 			auth->ah_cred = au->au_shcred;
233 		} else {
234 			xdrs.x_op = XDR_FREE;
235 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
236 			au->au_shcred.oa_base = NULL;
237 			auth->ah_cred = au->au_origcred;
238 		}
239 		marshal_new_auth(auth);
240 	}
241 	return (TRUE);
242 }
243 
244 static bool_t
245 authunix_refresh(auth)
246 	register AUTH *auth;
247 {
248 	register struct audata *au = AUTH_PRIVATE(auth);
249 	struct authunix_parms aup;
250 	struct timeval now;
251 	XDR xdrs;
252 	register int stat;
253 
254 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
255 		/* there is no hope.  Punt */
256 		return (FALSE);
257 	}
258 	au->au_shfaults ++;
259 
260 	/* first deserialize the creds back into a struct authunix_parms */
261 	aup.aup_machname = NULL;
262 	aup.aup_gids = (int *)NULL;
263 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
264 	    au->au_origcred.oa_length, XDR_DECODE);
265 	stat = xdr_authunix_parms(&xdrs, &aup);
266 	if (! stat)
267 		goto done;
268 
269 	/* update the time and serialize in place */
270 	(void)gettimeofday(&now, (struct timezone *)0);
271 	aup.aup_time = now.tv_sec;
272 	xdrs.x_op = XDR_ENCODE;
273 	XDR_SETPOS(&xdrs, 0);
274 	stat = xdr_authunix_parms(&xdrs, &aup);
275 	if (! stat)
276 		goto done;
277 	auth->ah_cred = au->au_origcred;
278 	marshal_new_auth(auth);
279 done:
280 	/* free the struct authunix_parms created by deserializing */
281 	xdrs.x_op = XDR_FREE;
282 	(void)xdr_authunix_parms(&xdrs, &aup);
283 	XDR_DESTROY(&xdrs);
284 	return (stat);
285 }
286 
287 static void
288 authunix_destroy(auth)
289 	register AUTH *auth;
290 {
291 	register struct audata *au = AUTH_PRIVATE(auth);
292 
293 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
294 
295 	if (au->au_shcred.oa_base != NULL)
296 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
297 
298 	mem_free(auth->ah_private, sizeof(struct audata));
299 
300 	if (auth->ah_verf.oa_base != NULL)
301 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
302 
303 	mem_free((caddr_t)auth, sizeof(*auth));
304 }
305 
306 /*
307  * Marshals (pre-serializes) an auth struct.
308  * sets private data, au_marshed and au_mpos
309  */
310 static void
311 marshal_new_auth(auth)
312 	register AUTH *auth;
313 {
314 	XDR		xdr_stream;
315 	register XDR	*xdrs = &xdr_stream;
316 	register struct audata *au = AUTH_PRIVATE(auth);
317 
318 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
319 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
320 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) {
321 		perror("auth_none.c - Fatal marshalling problem");
322 	} else {
323 		au->au_mpos = XDR_GETPOS(xdrs);
324 	}
325 	XDR_DESTROY(xdrs);
326 }
327