lib/libc/rpc/auth_unix.c

   1 /*      $NetBSD: auth_unix.c,v 1.22 2009/01/11 02:46:29 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 1.22 2009/01/11 02:46:29 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 }