xref: /freebsd/lib/libc/rpc/auth_unix.c (revision 0c43d89a0d8e976ca494d4837f4c1f3734d2c300)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 /*static char *sccsid = "from: @(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro";*/
32 /*static char *sccsid = "from: @(#)auth_unix.c	2.2 88/08/01 4.0 RPCSRC";*/
33 static char *rcsid = "$Id: auth_unix.c,v 1.1 1994/08/07 18:35:39 wollman Exp $";
34 #endif
35 
36 /*
37  * auth_unix.c, Implements UNIX style authentication parameters.
38  *
39  * Copyright (C) 1984, Sun Microsystems, Inc.
40  *
41  * The system is very weak.  The client uses no encryption for it's
42  * credentials and only sends null verifiers.  The server sends backs
43  * null verifiers or optionally a verifier that suggests a new short hand
44  * for the credentials.
45  *
46  */
47 
48 #include <stdio.h>
49 #include <stdlib.h>
50 
51 #include <sys/param.h>
52 #include <rpc/types.h>
53 #include <rpc/xdr.h>
54 #include <rpc/auth.h>
55 #include <rpc/auth_unix.h>
56 
57 /*
58  * Unix authenticator operations vector
59  */
60 static void	authunix_nextverf();
61 static bool_t	authunix_marshal();
62 static bool_t	authunix_validate();
63 static bool_t	authunix_refresh();
64 static void	authunix_destroy();
65 
66 static struct auth_ops auth_unix_ops = {
67 	authunix_nextverf,
68 	authunix_marshal,
69 	authunix_validate,
70 	authunix_refresh,
71 	authunix_destroy
72 };
73 
74 /*
75  * This struct is pointed to by the ah_private field of an auth_handle.
76  */
77 struct audata {
78 	struct opaque_auth	au_origcred;	/* original credentials */
79 	struct opaque_auth	au_shcred;	/* short hand cred */
80 	u_long			au_shfaults;	/* short hand cache faults */
81 	char			au_marshed[MAX_AUTH_BYTES];
82 	u_int			au_mpos;	/* xdr pos at end of marshed */
83 };
84 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
85 
86 static bool_t marshal_new_auth();
87 
88 /*
89  * This goop is here because some servers refuse to accept a
90  * credential with more than some number (usually 8) supplementary
91  * groups.  Blargh!
92  */
93 static int authunix_maxgrouplist = 0;
94 
95 int
96 set_rpc_maxgrouplist(int num)
97 {
98 	authunix_maxgrouplist = num;
99 }
100 
101 /*
102  * Create a unix style authenticator.
103  * Returns an auth handle with the given stuff in it.
104  */
105 AUTH *
106 authunix_create(machname, uid, gid, len, aup_gids)
107 	char *machname;
108 	int uid;
109 	int gid;
110 	register int len;
111 	int *aup_gids;
112 {
113 	struct authunix_parms aup;
114 	char mymem[MAX_AUTH_BYTES];
115 	struct timeval now;
116 	XDR xdrs;
117 	register AUTH *auth;
118 	register struct audata *au;
119 
120 	/*
121 	 * Allocate and set up auth handle
122 	 */
123 	auth = (AUTH *)mem_alloc(sizeof(*auth));
124 #ifndef KERNEL
125 	if (auth == NULL) {
126 		(void)fprintf(stderr, "authunix_create: out of memory\n");
127 		return (NULL);
128 	}
129 #endif
130 	au = (struct audata *)mem_alloc(sizeof(*au));
131 #ifndef KERNEL
132 	if (au == NULL) {
133 		(void)fprintf(stderr, "authunix_create: out of memory\n");
134 		return (NULL);
135 	}
136 #endif
137 	auth->ah_ops = &auth_unix_ops;
138 	auth->ah_private = (caddr_t)au;
139 	auth->ah_verf = au->au_shcred = _null_auth;
140 	au->au_shfaults = 0;
141 
142 	/*
143 	 * fill in param struct from the given params
144 	 */
145 	(void)gettimeofday(&now,  (struct timezone *)0);
146 	aup.aup_time = now.tv_sec;
147 	aup.aup_machname = machname;
148 	aup.aup_uid = uid;
149 	aup.aup_gid = gid;
150 	/* GW: continuation of max group list hack */
151 	if(authunix_maxgrouplist != 0) {
152 		aup.aup_len = ((len > authunix_maxgrouplist) ? len
153 			       : authunix_maxgrouplist);
154 	} else {
155 		aup.aup_len = (u_int)len;
156 	}
157 	aup.aup_gids = aup_gids;
158 
159 	/*
160 	 * Serialize the parameters into origcred
161 	 */
162 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
163 	if (! xdr_authunix_parms(&xdrs, &aup))
164 		abort();
165 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
166 	au->au_origcred.oa_flavor = AUTH_UNIX;
167 #ifdef KERNEL
168 	au->au_origcred.oa_base = mem_alloc((u_int) len);
169 #else
170 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
171 		(void)fprintf(stderr, "authunix_create: out of memory\n");
172 		return (NULL);
173 	}
174 #endif
175 	bcopy(mymem, au->au_origcred.oa_base, (u_int)len);
176 
177 	/*
178 	 * set auth handle to reflect new cred.
179 	 */
180 	auth->ah_cred = au->au_origcred;
181 	marshal_new_auth(auth);
182 	return (auth);
183 }
184 
185 /*
186  * Returns an auth handle with parameters determined by doing lots of
187  * syscalls.
188  */
189 AUTH *
190 authunix_create_default()
191 {
192 	register int len;
193 	char machname[MAX_MACHINE_NAME + 1];
194 	register int uid;
195 	register int gid;
196 	int gids[NGRPS];
197 	int i;
198 	gid_t real_gids[NGROUPS];
199 
200 	if (gethostname(machname, MAX_MACHINE_NAME) == -1)
201 		abort();
202 	machname[MAX_MACHINE_NAME] = 0;
203 	uid = geteuid();
204 	gid = getegid();
205 	if ((len = getgroups(NGROUPS, real_gids)) < 0)
206 		abort();
207 	if(len > NGRPS) len = NGRPS; /* GW: turn `gid_t's into `int's */
208 	for(i = 0; i < len; i++) {
209 		gids[i] = real_gids[i];
210 	}
211 	return (authunix_create(machname, uid, gid, len, gids));
212 }
213 
214 /*
215  * authunix operations
216  */
217 
218 static void
219 authunix_nextverf(auth)
220 	AUTH *auth;
221 {
222 	/* no action necessary */
223 }
224 
225 static bool_t
226 authunix_marshal(auth, xdrs)
227 	AUTH *auth;
228 	XDR *xdrs;
229 {
230 	register struct audata *au = AUTH_PRIVATE(auth);
231 
232 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
233 }
234 
235 static bool_t
236 authunix_validate(auth, verf)
237 	register AUTH *auth;
238 	struct opaque_auth verf;
239 {
240 	register struct audata *au;
241 	XDR xdrs;
242 
243 	if (verf.oa_flavor == AUTH_SHORT) {
244 		au = AUTH_PRIVATE(auth);
245 		xdrmem_create(&xdrs, verf.oa_base, verf.oa_length, XDR_DECODE);
246 
247 		if (au->au_shcred.oa_base != NULL) {
248 			mem_free(au->au_shcred.oa_base,
249 			    au->au_shcred.oa_length);
250 			au->au_shcred.oa_base = NULL;
251 		}
252 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
253 			auth->ah_cred = au->au_shcred;
254 		} else {
255 			xdrs.x_op = XDR_FREE;
256 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
257 			au->au_shcred.oa_base = NULL;
258 			auth->ah_cred = au->au_origcred;
259 		}
260 		marshal_new_auth(auth);
261 	}
262 	return (TRUE);
263 }
264 
265 static bool_t
266 authunix_refresh(auth)
267 	register AUTH *auth;
268 {
269 	register struct audata *au = AUTH_PRIVATE(auth);
270 	struct authunix_parms aup;
271 	struct timeval now;
272 	XDR xdrs;
273 	register int stat;
274 
275 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
276 		/* there is no hope.  Punt */
277 		return (FALSE);
278 	}
279 	au->au_shfaults ++;
280 
281 	/* first deserialize the creds back into a struct authunix_parms */
282 	aup.aup_machname = NULL;
283 	aup.aup_gids = (int *)NULL;
284 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
285 	    au->au_origcred.oa_length, XDR_DECODE);
286 	stat = xdr_authunix_parms(&xdrs, &aup);
287 	if (! stat)
288 		goto done;
289 
290 	/* update the time and serialize in place */
291 	(void)gettimeofday(&now, (struct timezone *)0);
292 	aup.aup_time = now.tv_sec;
293 	xdrs.x_op = XDR_ENCODE;
294 	XDR_SETPOS(&xdrs, 0);
295 	stat = xdr_authunix_parms(&xdrs, &aup);
296 	if (! stat)
297 		goto done;
298 	auth->ah_cred = au->au_origcred;
299 	marshal_new_auth(auth);
300 done:
301 	/* free the struct authunix_parms created by deserializing */
302 	xdrs.x_op = XDR_FREE;
303 	(void)xdr_authunix_parms(&xdrs, &aup);
304 	XDR_DESTROY(&xdrs);
305 	return (stat);
306 }
307 
308 static void
309 authunix_destroy(auth)
310 	register AUTH *auth;
311 {
312 	register struct audata *au = AUTH_PRIVATE(auth);
313 
314 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
315 
316 	if (au->au_shcred.oa_base != NULL)
317 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
318 
319 	mem_free(auth->ah_private, sizeof(struct audata));
320 
321 	if (auth->ah_verf.oa_base != NULL)
322 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
323 
324 	mem_free((caddr_t)auth, sizeof(*auth));
325 }
326 
327 /*
328  * Marshals (pre-serializes) an auth struct.
329  * sets private data, au_marshed and au_mpos
330  */
331 static bool_t
332 marshal_new_auth(auth)
333 	register AUTH *auth;
334 {
335 	XDR		xdr_stream;
336 	register XDR	*xdrs = &xdr_stream;
337 	register struct audata *au = AUTH_PRIVATE(auth);
338 
339 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
340 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
341 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) {
342 		perror("auth_none.c - Fatal marshalling problem");
343 	} else {
344 		au->au_mpos = XDR_GETPOS(xdrs);
345 	}
346 	XDR_DESTROY(xdrs);
347 }
348