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auth_unix.c revision 1.13
      1 /*	$NetBSD: auth_unix.c,v 1.13 1998/11/15 17:24:07 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 1.13 1998/11/15 17:24:07 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 "namespace.h"
     55 
     56 #include <sys/param.h>
     57 
     58 #include <err.h>
     59 #include <stdio.h>
     60 #include <stdlib.h>
     61 #include <string.h>
     62 #include <unistd.h>
     63 
     64 #include <rpc/types.h>
     65 #include <rpc/xdr.h>
     66 #include <rpc/auth.h>
     67 #include <rpc/auth_unix.h>
     68 
     69 #ifdef __weak_alias
     70 __weak_alias(authunix_create,_authunix_create);
     71 __weak_alias(authunix_create_default,_authunix_create_default);
     72 #endif
     73 
     74 
     75 /* auth_unix.c */
     76 static void authunix_nextverf __P((AUTH *));
     77 static bool_t authunix_marshal __P((AUTH *, XDR *));
     78 static bool_t authunix_validate __P((AUTH *, struct opaque_auth *));
     79 static bool_t authunix_refresh __P((AUTH *));
     80 static void authunix_destroy __P((AUTH *));
     81 static void marshal_new_auth __P((AUTH *));
     82 
     83 /*
     84  * Unix authenticator operations vector
     85  */
     86 static const struct auth_ops auth_unix_ops = {
     87 	authunix_nextverf,
     88 	authunix_marshal,
     89 	authunix_validate,
     90 	authunix_refresh,
     91 	authunix_destroy
     92 };
     93 
     94 /*
     95  * This struct is pointed to by the ah_private field of an auth_handle.
     96  */
     97 struct audata {
     98 	struct opaque_auth	au_origcred;	/* original credentials */
     99 	struct opaque_auth	au_shcred;	/* short hand cred */
    100 	u_long			au_shfaults;	/* short hand cache faults */
    101 	char			au_marshed[MAX_AUTH_BYTES];
    102 	u_int			au_mpos;	/* xdr pos at end of marshed */
    103 };
    104 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
    105 
    106 /*
    107  * Create a unix style authenticator.
    108  * Returns an auth handle with the given stuff in it.
    109  */
    110 AUTH *
    111 authunix_create(machname, uid, gid, len, aup_gids)
    112 	char *machname;
    113 	int uid;
    114 	int gid;
    115 	int len;
    116 	int *aup_gids;
    117 {
    118 	struct authunix_parms aup;
    119 	char mymem[MAX_AUTH_BYTES];
    120 	struct timeval now;
    121 	XDR xdrs;
    122 	AUTH *auth;
    123 	struct audata *au;
    124 
    125 	/*
    126 	 * Allocate and set up auth handle
    127 	 */
    128 	auth = (AUTH *)mem_alloc(sizeof(*auth));
    129 #ifndef KERNEL
    130 	if (auth == NULL) {
    131 		warnx("authunix_create: out of memory");
    132 		return (NULL);
    133 	}
    134 #endif
    135 	au = (struct audata *)mem_alloc(sizeof(*au));
    136 #ifndef KERNEL
    137 	if (au == NULL) {
    138 		warnx("authunix_create: out of memory");
    139 		return (NULL);
    140 	}
    141 #endif
    142 	auth->ah_ops = &auth_unix_ops;
    143 	auth->ah_private = au;
    144 	auth->ah_verf = au->au_shcred = _null_auth;
    145 	au->au_shfaults = 0;
    146 
    147 	/*
    148 	 * fill in param struct from the given params
    149 	 */
    150 	(void)gettimeofday(&now,  (struct timezone *)0);
    151 	aup.aup_time = now.tv_sec;
    152 	aup.aup_machname = machname;
    153 	aup.aup_uid = uid;
    154 	aup.aup_gid = gid;
    155 	aup.aup_len = (u_int)len;
    156 	aup.aup_gids = aup_gids;
    157 
    158 	/*
    159 	 * Serialize the parameters into origcred
    160 	 */
    161 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
    162 	if (! xdr_authunix_parms(&xdrs, &aup))
    163 		abort();
    164 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
    165 	au->au_origcred.oa_flavor = AUTH_UNIX;
    166 #ifdef KERNEL
    167 	au->au_origcred.oa_base = mem_alloc((u_int) len);
    168 #else
    169 	if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) {
    170 		warnx("authunix_create: out of memory");
    171 		return (NULL);
    172 	}
    173 #endif
    174 	memmove(au->au_origcred.oa_base, mymem, (size_t)len);
    175 
    176 	/*
    177 	 * set auth handle to reflect new cred.
    178 	 */
    179 	auth->ah_cred = au->au_origcred;
    180 	marshal_new_auth(auth);
    181 	return (auth);
    182 }
    183 
    184 /*
    185  * Returns an auth handle with parameters determined by doing lots of
    186  * syscalls.
    187  */
    188 AUTH *
    189 authunix_create_default()
    190 {
    191 	int len;
    192 	char machname[MAXHOSTNAMELEN + 1];
    193 	uid_t uid;
    194 	gid_t gid;
    195 	gid_t gids[NGRPS];
    196 
    197 	if (gethostname(machname, sizeof machname) == -1)
    198 		abort();
    199 	machname[sizeof(machname) - 1] = 0;
    200 	uid = geteuid();
    201 	gid = getegid();
    202 	if ((len = getgroups(NGRPS, gids)) < 0)
    203 		abort();
    204 	/* XXX: interface problem; those should all have been unsigned */
    205 	return (authunix_create(machname, (int)uid, (int)gid, len,
    206 	    (int *)gids));
    207 }
    208 
    209 /*
    210  * authunix operations
    211  */
    212 
    213 /* ARGSUSED */
    214 static void
    215 authunix_nextverf(auth)
    216 	AUTH *auth;
    217 {
    218 	/* no action necessary */
    219 }
    220 
    221 static bool_t
    222 authunix_marshal(auth, xdrs)
    223 	AUTH *auth;
    224 	XDR *xdrs;
    225 {
    226 	struct audata *au = AUTH_PRIVATE(auth);
    227 
    228 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
    229 }
    230 
    231 static bool_t
    232 authunix_validate(auth, verf)
    233 	AUTH *auth;
    234 	struct opaque_auth *verf;
    235 {
    236 	struct audata *au;
    237 	XDR xdrs;
    238 
    239 	if (verf->oa_flavor == AUTH_SHORT) {
    240 		au = AUTH_PRIVATE(auth);
    241 		xdrmem_create(&xdrs, verf->oa_base, verf->oa_length, XDR_DECODE);
    242 
    243 		if (au->au_shcred.oa_base != NULL) {
    244 			mem_free(au->au_shcred.oa_base,
    245 			    au->au_shcred.oa_length);
    246 			au->au_shcred.oa_base = NULL;
    247 		}
    248 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
    249 			auth->ah_cred = au->au_shcred;
    250 		} else {
    251 			xdrs.x_op = XDR_FREE;
    252 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
    253 			au->au_shcred.oa_base = NULL;
    254 			auth->ah_cred = au->au_origcred;
    255 		}
    256 		marshal_new_auth(auth);
    257 	}
    258 	return (TRUE);
    259 }
    260 
    261 static bool_t
    262 authunix_refresh(auth)
    263 	AUTH *auth;
    264 {
    265 	struct audata *au = AUTH_PRIVATE(auth);
    266 	struct authunix_parms aup;
    267 	struct timeval now;
    268 	XDR xdrs;
    269 	int stat;
    270 
    271 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
    272 		/* there is no hope.  Punt */
    273 		return (FALSE);
    274 	}
    275 	au->au_shfaults ++;
    276 
    277 	/* first deserialize the creds back into a struct authunix_parms */
    278 	aup.aup_machname = NULL;
    279 	aup.aup_gids = (int *)NULL;
    280 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
    281 	    au->au_origcred.oa_length, XDR_DECODE);
    282 	stat = xdr_authunix_parms(&xdrs, &aup);
    283 	if (! stat)
    284 		goto done;
    285 
    286 	/* update the time and serialize in place */
    287 	(void)gettimeofday(&now, (struct timezone *)0);
    288 	aup.aup_time = now.tv_sec;
    289 	xdrs.x_op = XDR_ENCODE;
    290 	XDR_SETPOS(&xdrs, 0);
    291 	stat = xdr_authunix_parms(&xdrs, &aup);
    292 	if (! stat)
    293 		goto done;
    294 	auth->ah_cred = au->au_origcred;
    295 	marshal_new_auth(auth);
    296 done:
    297 	/* free the struct authunix_parms created by deserializing */
    298 	xdrs.x_op = XDR_FREE;
    299 	(void)xdr_authunix_parms(&xdrs, &aup);
    300 	XDR_DESTROY(&xdrs);
    301 	return (stat);
    302 }
    303 
    304 static void
    305 authunix_destroy(auth)
    306 	AUTH *auth;
    307 {
    308 	struct audata *au = AUTH_PRIVATE(auth);
    309 
    310 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
    311 
    312 	if (au->au_shcred.oa_base != NULL)
    313 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
    314 
    315 	mem_free(auth->ah_private, sizeof(struct audata));
    316 
    317 	if (auth->ah_verf.oa_base != NULL)
    318 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
    319 
    320 	mem_free(auth, sizeof(*auth));
    321 }
    322 
    323 /*
    324  * Marshals (pre-serializes) an auth struct.
    325  * sets private data, au_marshed and au_mpos
    326  */
    327 static void
    328 marshal_new_auth(auth)
    329 	AUTH *auth;
    330 {
    331 	XDR	xdr_stream;
    332 	XDR	*xdrs = &xdr_stream;
    333 	struct audata *au = AUTH_PRIVATE(auth);
    334 
    335 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
    336 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
    337 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
    338 		warnx("auth_none.c - Fatal marshalling problem");
    339 	else
    340 		au->au_mpos = XDR_GETPOS(xdrs);
    341 	XDR_DESTROY(xdrs);
    342 }
    343