xref: /freebsd/crypto/krb5/src/lib/rpc/auth_unix.c (revision 7f2fe78b9dd5f51c821d771b63d2e096f6fd49e9)
1 /* @(#)auth_unix.c	2.2 88/08/01 4.0 RPCSRC */
2 /*
3  * Copyright (c) 2010, Oracle America, Inc.
4  *
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are met:
9  *
10  *     * Redistributions of source code must retain the above copyright
11  *       notice, this list of conditions and the following disclaimer.
12  *
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *
18  *     * Neither the name of the "Oracle America, Inc." nor the names of
19  *       its contributors may be used to endorse or promote products
20  *       derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
23  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
25  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
28  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
29  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 #if !defined(lint) && defined(SCCSIDS)
35 static char sccsid[] = "@(#)auth_unix.c 1.19 87/08/11 Copyr 1984 Sun Micro";
36 #endif
37 
38 /*
39  * auth_unix.c, Implements UNIX style authentication parameters.
40  *
41  * The system is very weak.  The client uses no encryption for its
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 "autoconf.h"
49 #include <stdio.h>
50 #include <unistd.h>
51 #include <string.h>
52 
53 #include <gssrpc/types.h>
54 #include <gssrpc/xdr.h>
55 #include <gssrpc/auth.h>
56 #include <gssrpc/auth_unix.h>
57 
58 /*
59  * Unix authenticator operations vector
60  */
61 static void	authunix_nextverf(AUTH *);
62 static bool_t	authunix_marshal(AUTH *, XDR *);
63 static bool_t	authunix_validate(AUTH *, struct opaque_auth *);
64 static bool_t	authunix_refresh(AUTH *, struct rpc_msg *);
65 static void	authunix_destroy(AUTH *);
66 static bool_t	authunix_wrap(AUTH *, XDR *, xdrproc_t, caddr_t);
67 
68 static struct auth_ops auth_unix_ops = {
69 	authunix_nextverf,
70 	authunix_marshal,
71 	authunix_validate,
72 	authunix_refresh,
73 	authunix_destroy,
74 	authunix_wrap,
75 	authunix_wrap
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 	uint32_t		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(AUTH *);
91 
92 
93 /*
94  * Create a unix style authenticator.
95  * Returns an auth handle with the given stuff in it.
96  */
97 AUTH *
authunix_create(char * machname,int uid,int gid,int len,int * aup_gids)98 authunix_create(
99 	char *machname,
100 	int uid,
101 	int gid,
102 	int len,
103 	int *aup_gids)
104 {
105 	struct authunix_parms aup;
106 	char mymem[MAX_AUTH_BYTES];
107 	struct timeval now;
108 	XDR xdrs;
109 	AUTH *auth;
110 	struct audata *au;
111 
112 	/*
113 	 * Allocate and set up auth handle
114 	 */
115 	auth = (AUTH *)mem_alloc(sizeof(*auth));
116 #ifndef KERNEL
117 	if (auth == NULL) {
118 		(void)fprintf(stderr, "authunix_create: out of memory\n");
119 		return (NULL);
120 	}
121 #endif
122 	au = (struct audata *)mem_alloc(sizeof(*au));
123 #ifndef KERNEL
124 	if (au == NULL) {
125 		(void)fprintf(stderr, "authunix_create: out of memory\n");
126 		return (NULL);
127 	}
128 #endif
129 	auth->ah_ops = &auth_unix_ops;
130 	auth->ah_private = (caddr_t)au;
131 	auth->ah_verf = au->au_shcred = gssrpc__null_auth;
132 	au->au_shfaults = 0;
133 
134 	/*
135 	 * fill in param struct from the given params
136 	 */
137 	(void)gettimeofday(&now,  (struct timezone *)0);
138 	aup.aup_time = now.tv_sec;
139 	aup.aup_machname = machname;
140 	aup.aup_uid = uid;
141 	aup.aup_gid = gid;
142 	aup.aup_len = (u_int)len;
143 	aup.aup_gids = aup_gids;
144 
145 	/*
146 	 * Serialize the parameters into origcred
147 	 */
148 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
149 	if (! xdr_authunix_parms(&xdrs, &aup))
150 		abort();
151 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
152 	au->au_origcred.oa_flavor = AUTH_UNIX;
153 #ifdef KERNEL
154 	au->au_origcred.oa_base = mem_alloc((u_int) len);
155 #else
156 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
157 		(void)fprintf(stderr, "authunix_create: out of memory\n");
158 		return (NULL);
159 	}
160 #endif
161 	memmove(au->au_origcred.oa_base, mymem, (u_int)len);
162 
163 	/*
164 	 * set auth handle to reflect new cred.
165 	 */
166 	auth->ah_cred = au->au_origcred;
167 	marshal_new_auth(auth);
168 	return (auth);
169 }
170 
171 /*
172  * Returns an auth handle with parameters determined by doing lots of
173  * syscalls.
174  */
175 AUTH *
authunix_create_default(void)176 authunix_create_default(void)
177 {
178 	int len;
179 	char machname[MAX_MACHINE_NAME + 1];
180 	int uid;
181 	int gid;
182 	GETGROUPS_T gids[NGRPS];
183 	int igids[NGRPS], i;
184 
185 	if (gethostname(machname, MAX_MACHINE_NAME) == -1)
186 		abort();
187 	machname[MAX_MACHINE_NAME] = 0;
188 	uid = geteuid();
189 	gid = getegid();
190 	if ((len = getgroups(NGRPS, gids)) < 0)
191 		abort();
192 	for(i = 0; i < NGRPS; i++) {
193 	        igids[i] = gids[i];
194 	}
195 	return (authunix_create(machname, uid, gid, len, igids));
196 }
197 
198 /*
199  * authunix operations
200  */
201 
202 static void
authunix_nextverf(AUTH * auth)203 authunix_nextverf(AUTH *auth)
204 {
205 	/* no action necessary */
206 }
207 
208 static bool_t
authunix_marshal(AUTH * auth,XDR * xdrs)209 authunix_marshal(AUTH *auth, XDR *xdrs)
210 {
211 	struct audata *au = AUTH_PRIVATE(auth);
212 
213 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
214 }
215 
216 static bool_t
authunix_validate(AUTH * auth,struct opaque_auth * verf)217 authunix_validate(AUTH *auth, struct opaque_auth *verf)
218 {
219 	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
authunix_refresh(AUTH * auth,struct rpc_msg * msg)245 authunix_refresh(AUTH *auth, struct rpc_msg *msg)
246 {
247 	struct audata *au = AUTH_PRIVATE(auth);
248 	struct authunix_parms aup;
249 	struct timeval now;
250 	XDR xdrs;
251 	int stat;
252 
253 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
254 		/* there is no hope.  Punt */
255 		return (FALSE);
256 	}
257 	au->au_shfaults ++;
258 
259 	/* first deserialize the creds back into a struct authunix_parms */
260 	aup.aup_machname = NULL;
261 	aup.aup_gids = (int *)NULL;
262 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
263 	    au->au_origcred.oa_length, XDR_DECODE);
264 	stat = xdr_authunix_parms(&xdrs, &aup);
265 	if (! stat)
266 		goto done;
267 
268 	/* update the time and serialize in place */
269 	(void)gettimeofday(&now, (struct timezone *)0);
270 	aup.aup_time = now.tv_sec;
271 	xdrs.x_op = XDR_ENCODE;
272 	XDR_SETPOS(&xdrs, 0);
273 	stat = xdr_authunix_parms(&xdrs, &aup);
274 	if (! stat)
275 		goto done;
276 	auth->ah_cred = au->au_origcred;
277 	marshal_new_auth(auth);
278 done:
279 	/* free the struct authunix_parms created by deserializing */
280 	xdrs.x_op = XDR_FREE;
281 	(void)xdr_authunix_parms(&xdrs, &aup);
282 	XDR_DESTROY(&xdrs);
283 	return (stat);
284 }
285 
286 static void
authunix_destroy(AUTH * auth)287 authunix_destroy(AUTH *auth)
288 {
289 	struct audata *au = AUTH_PRIVATE(auth);
290 
291 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
292 
293 	if (au->au_shcred.oa_base != NULL)
294 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
295 
296 	mem_free(auth->ah_private, sizeof(struct audata));
297 
298 	if (auth->ah_verf.oa_base != NULL)
299 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
300 
301 	mem_free((caddr_t)auth, sizeof(*auth));
302 }
303 
304 /*
305  * Marshals (pre-serializes) an auth struct.
306  * sets private data, au_marshed and au_mpos
307  */
308 static void
marshal_new_auth(AUTH * auth)309 marshal_new_auth(AUTH *auth)
310 {
311 	XDR		xdr_stream;
312 	XDR	*xdrs = &xdr_stream;
313 	struct audata *au = AUTH_PRIVATE(auth);
314 
315 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
316 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
317 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) {
318 		perror("auth_none.c - Fatal marshalling problem");
319 	} else {
320 		au->au_mpos = XDR_GETPOS(xdrs);
321 	}
322 	XDR_DESTROY(xdrs);
323 }
324 
325 static bool_t
authunix_wrap(AUTH * auth,XDR * xdrs,xdrproc_t xfunc,caddr_t xwhere)326 authunix_wrap(AUTH *auth, XDR *xdrs, xdrproc_t xfunc, caddr_t xwhere)
327 {
328 	return ((*xfunc)(xdrs, xwhere));
329 }
330