xref: /freebsd/lib/libc/rpc/auth_unix.c (revision e627b39baccd1ec9129690167cf5e6d860509655)
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 1.5 1995/10/22 14:51:08 phk 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 #include <unistd.h>
51 #include <string.h>
52 
53 #include <sys/param.h>
54 #include <rpc/types.h>
55 #include <rpc/xdr.h>
56 #include <rpc/auth.h>
57 #include <rpc/auth_unix.h>
58 
59 bool_t xdr_opaque_auth(XDR *xdrs, struct opaque_auth *ap);
60 
61 /*
62  * Unix authenticator operations vector
63  */
64 static void	authunix_nextverf();
65 static bool_t	authunix_marshal();
66 static bool_t	authunix_validate();
67 static bool_t	authunix_refresh();
68 static void	authunix_destroy();
69 
70 static struct auth_ops auth_unix_ops = {
71 	authunix_nextverf,
72 	authunix_marshal,
73 	authunix_validate,
74 	authunix_refresh,
75 	authunix_destroy
76 };
77 
78 /*
79  * This struct is pointed to by the ah_private field of an auth_handle.
80  */
81 struct audata {
82 	struct opaque_auth	au_origcred;	/* original credentials */
83 	struct opaque_auth	au_shcred;	/* short hand cred */
84 	u_long			au_shfaults;	/* short hand cache faults */
85 	char			au_marshed[MAX_AUTH_BYTES];
86 	u_int			au_mpos;	/* xdr pos at end of marshed */
87 };
88 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
89 
90 static void marshal_new_auth();
91 
92 /*
93  * This goop is here because some servers refuse to accept a
94  * credential with more than some number (usually 8) supplementary
95  * groups.  Blargh!
96  */
97 static int authunix_maxgrouplist = 0;
98 
99 void
100 set_rpc_maxgrouplist(int num)
101 {
102 	authunix_maxgrouplist = num;
103 }
104 
105 /*
106  * Create a unix style authenticator.
107  * Returns an auth handle with the given stuff in it.
108  */
109 AUTH *
110 authunix_create(machname, uid, gid, len, aup_gids)
111 	char *machname;
112 	int uid;
113 	int gid;
114 	register int len;
115 	int *aup_gids;
116 {
117 	struct authunix_parms aup;
118 	char mymem[MAX_AUTH_BYTES];
119 	struct timeval now;
120 	XDR xdrs;
121 	register AUTH *auth;
122 	register struct audata *au;
123 
124 	/*
125 	 * Allocate and set up auth handle
126 	 */
127 	auth = (AUTH *)mem_alloc(sizeof(*auth));
128 #ifndef KERNEL
129 	if (auth == NULL) {
130 		(void)fprintf(stderr, "authunix_create: out of memory\n");
131 		return (NULL);
132 	}
133 #endif
134 	au = (struct audata *)mem_alloc(sizeof(*au));
135 #ifndef KERNEL
136 	if (au == NULL) {
137 		(void)fprintf(stderr, "authunix_create: out of memory\n");
138 		return (NULL);
139 	}
140 #endif
141 	auth->ah_ops = &auth_unix_ops;
142 	auth->ah_private = (caddr_t)au;
143 	auth->ah_verf = au->au_shcred = _null_auth;
144 	au->au_shfaults = 0;
145 
146 	/*
147 	 * fill in param struct from the given params
148 	 */
149 	(void)gettimeofday(&now,  (struct timezone *)0);
150 	aup.aup_time = now.tv_sec;
151 	aup.aup_machname = machname;
152 	aup.aup_uid = uid;
153 	aup.aup_gid = gid;
154 	/* GW: continuation of max group list hack */
155 	if(authunix_maxgrouplist != 0) {
156 		aup.aup_len = ((len < authunix_maxgrouplist) ? len
157 			       : authunix_maxgrouplist);
158 	} else {
159 		aup.aup_len = (u_int)len;
160 	}
161 	aup.aup_gids = aup_gids;
162 
163 	/*
164 	 * Serialize the parameters into origcred
165 	 */
166 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
167 	if (! xdr_authunix_parms(&xdrs, &aup))
168 		abort();
169 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
170 	au->au_origcred.oa_flavor = AUTH_UNIX;
171 #ifdef KERNEL
172 	au->au_origcred.oa_base = mem_alloc((u_int) len);
173 #else
174 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
175 		(void)fprintf(stderr, "authunix_create: out of memory\n");
176 		return (NULL);
177 	}
178 #endif
179 	bcopy(mymem, au->au_origcred.oa_base, (u_int)len);
180 
181 	/*
182 	 * set auth handle to reflect new cred.
183 	 */
184 	auth->ah_cred = au->au_origcred;
185 	marshal_new_auth(auth);
186 	return (auth);
187 }
188 
189 /*
190  * Returns an auth handle with parameters determined by doing lots of
191  * syscalls.
192  */
193 AUTH *
194 authunix_create_default()
195 {
196 	register int len;
197 	char machname[MAX_MACHINE_NAME + 1];
198 	register int uid;
199 	register int gid;
200 	int gids[NGRPS];
201 	int i;
202 	gid_t real_gids[NGROUPS];
203 
204 	if (gethostname(machname, MAX_MACHINE_NAME) == -1)
205 		abort();
206 	machname[MAX_MACHINE_NAME] = 0;
207 	uid = (int)geteuid();
208 	gid = (int)getegid();
209 	if ((len = getgroups(NGROUPS, real_gids)) < 0)
210 		abort();
211 	if(len > NGRPS) len = NGRPS; /* GW: turn `gid_t's into `int's */
212 	for(i = 0; i < len; i++) {
213 		gids[i] = (int)real_gids[i];
214 	}
215 	return (authunix_create(machname, uid, gid, len, gids));
216 }
217 
218 /*
219  * authunix operations
220  */
221 
222 static void
223 authunix_nextverf(auth)
224 	AUTH *auth;
225 {
226 	/* no action necessary */
227 }
228 
229 static bool_t
230 authunix_marshal(auth, xdrs)
231 	AUTH *auth;
232 	XDR *xdrs;
233 {
234 	register struct audata *au = AUTH_PRIVATE(auth);
235 
236 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
237 }
238 
239 static bool_t
240 authunix_validate(auth, verf)
241 	register AUTH *auth;
242 	struct opaque_auth verf;
243 {
244 	register struct audata *au;
245 	XDR xdrs;
246 
247 	if (verf.oa_flavor == AUTH_SHORT) {
248 		au = AUTH_PRIVATE(auth);
249 		xdrmem_create(&xdrs, verf.oa_base, verf.oa_length, XDR_DECODE);
250 
251 		if (au->au_shcred.oa_base != NULL) {
252 			mem_free(au->au_shcred.oa_base,
253 			    au->au_shcred.oa_length);
254 			au->au_shcred.oa_base = NULL;
255 		}
256 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
257 			auth->ah_cred = au->au_shcred;
258 		} else {
259 			xdrs.x_op = XDR_FREE;
260 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
261 			au->au_shcred.oa_base = NULL;
262 			auth->ah_cred = au->au_origcred;
263 		}
264 		marshal_new_auth(auth);
265 	}
266 	return (TRUE);
267 }
268 
269 static bool_t
270 authunix_refresh(auth)
271 	register AUTH *auth;
272 {
273 	register struct audata *au = AUTH_PRIVATE(auth);
274 	struct authunix_parms aup;
275 	struct timeval now;
276 	XDR xdrs;
277 	register int stat;
278 
279 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
280 		/* there is no hope.  Punt */
281 		return (FALSE);
282 	}
283 	au->au_shfaults ++;
284 
285 	/* first deserialize the creds back into a struct authunix_parms */
286 	aup.aup_machname = NULL;
287 	aup.aup_gids = (int *)NULL;
288 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
289 	    au->au_origcred.oa_length, XDR_DECODE);
290 	stat = xdr_authunix_parms(&xdrs, &aup);
291 	if (! stat)
292 		goto done;
293 
294 	/* update the time and serialize in place */
295 	(void)gettimeofday(&now, (struct timezone *)0);
296 	aup.aup_time = now.tv_sec;
297 	xdrs.x_op = XDR_ENCODE;
298 	XDR_SETPOS(&xdrs, 0);
299 	stat = xdr_authunix_parms(&xdrs, &aup);
300 	if (! stat)
301 		goto done;
302 	auth->ah_cred = au->au_origcred;
303 	marshal_new_auth(auth);
304 done:
305 	/* free the struct authunix_parms created by deserializing */
306 	xdrs.x_op = XDR_FREE;
307 	(void)xdr_authunix_parms(&xdrs, &aup);
308 	XDR_DESTROY(&xdrs);
309 	return (stat);
310 }
311 
312 static void
313 authunix_destroy(auth)
314 	register AUTH *auth;
315 {
316 	register struct audata *au = AUTH_PRIVATE(auth);
317 
318 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
319 
320 	if (au->au_shcred.oa_base != NULL)
321 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
322 
323 	mem_free(auth->ah_private, sizeof(struct audata));
324 
325 	if (auth->ah_verf.oa_base != NULL)
326 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
327 
328 	mem_free((caddr_t)auth, sizeof(*auth));
329 }
330 
331 /*
332  * Marshals (pre-serializes) an auth struct.
333  * sets private data, au_marshed and au_mpos
334  */
335 static void
336 marshal_new_auth(auth)
337 	register AUTH *auth;
338 {
339 	XDR		xdr_stream;
340 	register XDR	*xdrs = &xdr_stream;
341 	register struct audata *au = AUTH_PRIVATE(auth);
342 
343 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
344 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
345 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) {
346 		perror("auth_none.c - Fatal marshalling problem");
347 	} else {
348 		au->au_mpos = XDR_GETPOS(xdrs);
349 	}
350 	XDR_DESTROY(xdrs);
351 }
352