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auth_unix.c revision 1.21.8.2
      1 /*	$NetBSD: auth_unix.c,v 1.21.8.2 2008/11/08 21:45:38 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 1.21.8.2 2008/11/08 21:45:38 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 #include "reentrant.h"
     56 #include <sys/param.h>
     57 
     58 #include <assert.h>
     59 #include <err.h>
     60 #include <stdio.h>
     61 #include <stdlib.h>
     62 #include <string.h>
     63 #include <unistd.h>
     64 
     65 #include <rpc/types.h>
     66 #include <rpc/xdr.h>
     67 #include <rpc/auth.h>
     68 #include <rpc/auth_unix.h>
     69 
     70 #ifdef __weak_alias
     71 __weak_alias(authunix_create,_authunix_create)
     72 __weak_alias(authunix_create_default,_authunix_create_default)
     73 #endif
     74 
     75 
     76 /* auth_unix.c */
     77 static void authunix_nextverf __P((AUTH *));
     78 static bool_t authunix_marshal __P((AUTH *, XDR *));
     79 static bool_t authunix_validate __P((AUTH *, struct opaque_auth *));
     80 static bool_t authunix_refresh __P((AUTH *));
     81 static void authunix_destroy __P((AUTH *));
     82 static void marshal_new_auth __P((AUTH *));
     83 static const struct auth_ops *authunix_ops __P((void));
     84 
     85 /*
     86  * This struct is pointed to by the ah_private field of an auth_handle.
     87  */
     88 struct audata {
     89 	struct opaque_auth	au_origcred;	/* original credentials */
     90 	struct opaque_auth	au_shcred;	/* short hand cred */
     91 	u_long			au_shfaults;	/* short hand cache faults */
     92 	char			au_marshed[MAX_AUTH_BYTES];
     93 	u_int			au_mpos;	/* xdr pos at end of marshed */
     94 };
     95 #define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)
     96 
     97 /*
     98  * Create a unix style authenticator.
     99  * Returns an auth handle with the given stuff in it.
    100  */
    101 AUTH *
    102 authunix_create(machname, uid, gid, len, aup_gids)
    103 	char *machname;
    104 	int uid;
    105 	int gid;
    106 	int len;
    107 	int *aup_gids;
    108 {
    109 	struct authunix_parms aup;
    110 	char mymem[MAX_AUTH_BYTES];
    111 	struct timeval now;
    112 	XDR xdrs;
    113 	AUTH *auth;
    114 	struct audata *au;
    115 
    116 	/*
    117 	 * Allocate and set up auth handle
    118 	 */
    119 	au = NULL;
    120 	auth = mem_alloc(sizeof(*auth));
    121 #ifndef KERNEL
    122 	if (auth == NULL) {
    123 		warnx("authunix_create: out of memory");
    124 		goto cleanup_authunix_create;
    125 	}
    126 #endif
    127 	au = mem_alloc(sizeof(*au));
    128 #ifndef KERNEL
    129 	if (au == NULL) {
    130 		warnx("authunix_create: out of memory");
    131 		goto cleanup_authunix_create;
    132 	}
    133 #endif
    134 	auth->ah_ops = authunix_ops();
    135 	auth->ah_private = au;
    136 	auth->ah_verf = au->au_shcred = _null_auth;
    137 	au->au_shfaults = 0;
    138 	au->au_origcred.oa_base = NULL;
    139 
    140 	/*
    141 	 * fill in param struct from the given params
    142 	 */
    143 	(void)gettimeofday(&now, NULL);
    144 	aup.aup_time = (u_long)now.tv_sec;	/* XXX: truncate on 32 bit */
    145 	aup.aup_machname = machname;
    146 	aup.aup_uid = uid;
    147 	aup.aup_gid = gid;
    148 	aup.aup_len = (u_int)len;
    149 	aup.aup_gids = aup_gids;
    150 
    151 	/*
    152 	 * Serialize the parameters into origcred
    153 	 */
    154 	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
    155 	if (! xdr_authunix_parms(&xdrs, &aup))
    156 		abort();
    157 	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
    158 	au->au_origcred.oa_flavor = AUTH_UNIX;
    159 #ifdef KERNEL
    160 	au->au_origcred.oa_base = mem_alloc((size_t)len);
    161 #else
    162 	if ((au->au_origcred.oa_base = mem_alloc((size_t)len)) == NULL) {
    163 		warnx("authunix_create: out of memory");
    164 		goto cleanup_authunix_create;
    165 	}
    166 #endif
    167 	memmove(au->au_origcred.oa_base, mymem, (size_t)len);
    168 
    169 	/*
    170 	 * set auth handle to reflect new cred.
    171 	 */
    172 	auth->ah_cred = au->au_origcred;
    173 	marshal_new_auth(auth);
    174 	return (auth);
    175 #ifndef KERNEL
    176  cleanup_authunix_create:
    177 	if (auth)
    178 		mem_free(auth, sizeof(*auth));
    179 	if (au) {
    180 		if (au->au_origcred.oa_base)
    181 			mem_free(au->au_origcred.oa_base, (u_int)len);
    182 		mem_free(au, sizeof(*au));
    183 	}
    184 	return (NULL);
    185 #endif
    186 }
    187 
    188 /*
    189  * Returns an auth handle with parameters determined by doing lots of
    190  * syscalls.
    191  */
    192 AUTH *
    193 authunix_create_default()
    194 {
    195 	int len;
    196 	char machname[MAXHOSTNAMELEN + 1];
    197 	uid_t uid;
    198 	gid_t gid;
    199 	gid_t gids[NGRPS];
    200 
    201 	if (gethostname(machname, sizeof machname) == -1)
    202 		abort();
    203 	machname[sizeof(machname) - 1] = 0;
    204 	uid = geteuid();
    205 	gid = getegid();
    206 	if ((len = getgroups(NGRPS, gids)) < 0)
    207 		abort();
    208 	/* XXX: interface problem; those should all have been unsigned */
    209 	return (authunix_create(machname, (int)uid, (int)gid, len,
    210 	    (int *)gids));
    211 }
    212 
    213 /*
    214  * authunix operations
    215  */
    216 
    217 /* ARGSUSED */
    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 	struct audata *au;
    231 
    232 	_DIAGASSERT(auth != NULL);
    233 	_DIAGASSERT(xdrs != NULL);
    234 
    235 	au = AUTH_PRIVATE(auth);
    236 	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
    237 }
    238 
    239 static bool_t
    240 authunix_validate(auth, verf)
    241 	AUTH *auth;
    242 	struct opaque_auth *verf;
    243 {
    244 	struct audata *au;
    245 	XDR xdrs;
    246 
    247 	_DIAGASSERT(auth != NULL);
    248 	_DIAGASSERT(verf != NULL);
    249 
    250 	if (verf->oa_flavor == AUTH_SHORT) {
    251 		au = AUTH_PRIVATE(auth);
    252 		xdrmem_create(&xdrs, verf->oa_base, verf->oa_length,
    253 		    XDR_DECODE);
    254 
    255 		if (au->au_shcred.oa_base != NULL) {
    256 			mem_free(au->au_shcred.oa_base,
    257 			    au->au_shcred.oa_length);
    258 			au->au_shcred.oa_base = NULL;
    259 		}
    260 		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
    261 			auth->ah_cred = au->au_shcred;
    262 		} else {
    263 			xdrs.x_op = XDR_FREE;
    264 			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
    265 			au->au_shcred.oa_base = NULL;
    266 			auth->ah_cred = au->au_origcred;
    267 		}
    268 		marshal_new_auth(auth);
    269 	}
    270 	return (TRUE);
    271 }
    272 
    273 static bool_t
    274 authunix_refresh(auth)
    275 	AUTH *auth;
    276 {
    277 	struct audata *au = AUTH_PRIVATE(auth);
    278 	struct authunix_parms aup;
    279 	struct timeval now;
    280 	XDR xdrs;
    281 	int stat;
    282 
    283 	_DIAGASSERT(auth != NULL);
    284 
    285 	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
    286 		/* there is no hope.  Punt */
    287 		return (FALSE);
    288 	}
    289 	au->au_shfaults++;
    290 
    291 	/* first deserialize the creds back into a struct authunix_parms */
    292 	aup.aup_machname = NULL;
    293 	aup.aup_gids = NULL;
    294 	xdrmem_create(&xdrs, au->au_origcred.oa_base,
    295 	    au->au_origcred.oa_length, XDR_DECODE);
    296 	stat = xdr_authunix_parms(&xdrs, &aup);
    297 	if (! stat)
    298 		goto done;
    299 
    300 	/* update the time and serialize in place */
    301 	(void)gettimeofday(&now, NULL);
    302 	aup.aup_time = (u_long)now.tv_sec;	/* XXX: truncate on 32 bit */
    303 	xdrs.x_op = XDR_ENCODE;
    304 	XDR_SETPOS(&xdrs, 0);
    305 	stat = xdr_authunix_parms(&xdrs, &aup);
    306 	if (! stat)
    307 		goto done;
    308 	auth->ah_cred = au->au_origcred;
    309 	marshal_new_auth(auth);
    310 done:
    311 	/* free the struct authunix_parms created by deserializing */
    312 	xdrs.x_op = XDR_FREE;
    313 	(void)xdr_authunix_parms(&xdrs, &aup);
    314 	XDR_DESTROY(&xdrs);
    315 	return (stat);
    316 }
    317 
    318 static void
    319 authunix_destroy(auth)
    320 	AUTH *auth;
    321 {
    322 	struct audata *au;
    323 
    324 	_DIAGASSERT(auth != NULL);
    325 
    326 	au = AUTH_PRIVATE(auth);
    327 	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
    328 
    329 	if (au->au_shcred.oa_base != NULL)
    330 		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
    331 
    332 	mem_free(auth->ah_private, sizeof(struct audata));
    333 
    334 	if (auth->ah_verf.oa_base != NULL)
    335 		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
    336 
    337 	mem_free(auth, sizeof(*auth));
    338 }
    339 
    340 /*
    341  * Marshals (pre-serializes) an auth struct.
    342  * sets private data, au_marshed and au_mpos
    343  */
    344 static void
    345 marshal_new_auth(auth)
    346 	AUTH *auth;
    347 {
    348 	XDR	xdr_stream;
    349 	XDR	*xdrs = &xdr_stream;
    350 	struct audata *au;
    351 
    352 	_DIAGASSERT(auth != NULL);
    353 
    354 	au = AUTH_PRIVATE(auth);
    355 	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
    356 	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
    357 	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
    358 		warnx("auth_none.c - Fatal marshalling problem");
    359 	else
    360 		au->au_mpos = XDR_GETPOS(xdrs);
    361 	XDR_DESTROY(xdrs);
    362 }
    363 
    364 static const struct auth_ops *
    365 authunix_ops()
    366 {
    367 	static struct auth_ops ops;
    368 #ifdef _REENTRANT
    369 	extern mutex_t ops_lock;
    370 #endif
    371 
    372 	/* VARIABLES PROTECTED BY ops_lock: ops */
    373 
    374 	mutex_lock(&ops_lock);
    375 	if (ops.ah_nextverf == NULL) {
    376 		ops.ah_nextverf = authunix_nextverf;
    377 		ops.ah_marshal = authunix_marshal;
    378 		ops.ah_validate = authunix_validate;
    379 		ops.ah_refresh = authunix_refresh;
    380 		ops.ah_destroy = authunix_destroy;
    381 	}
    382 	mutex_unlock(&ops_lock);
    383 	return (&ops);
    384 }
    385