sunrpc/auth_unix.c

   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  * Copyright (C) 1984, Sun Microsystems, Inc.
  31  */
  32 /*
  33  * auth_unix.c, Implements UNIX style authentication parameters.
  34  *
  35  * The system is very weak.  The client uses no encryption for it's
  36  * credentials and only sends null verifiers.  The server sends backs
  37  * null verifiers or optionally a verifier that suggests a new short hand
  38  * for the credentials.
  39  */
  40
  41 #include <limits.h>
  42 #include <stdio.h>
  43 #include <string.h>
  44 #include <unistd.h>
  45 #include <libintl.h>
  46 #include <sys/param.h>
  47
  48 #include <rpc/types.h>
  49 #include <rpc/xdr.h>
  50 #include <rpc/auth.h>
  51 #include <rpc/auth_unix.h>
  52
  53 #ifdef USE_IN_LIBIO
  54 # include <wchar.h>
  55 #endif
  56
  57 /*
  58  * Unix authenticator operations vector
  59  */
  60 static void authunix_nextverf (AUTH *);
  61 static bool_t authunix_marshal (AUTH *, XDR *);
  62 static bool_t authunix_validate (AUTH *, struct opaque_auth *);
  63 static bool_t authunix_refresh (AUTH *);
  64 static void authunix_destroy (AUTH *);
  65
  66 static struct auth_ops auth_unix_ops = {
  67   authunix_nextverf,
  68   authunix_marshal,
  69   authunix_validate,
  70   authunix_refresh,
  71   authunix_destroy
  72 };
  73
  74 /*
  75  * This struct is pointed to by the ah_private field of an auth_handle.
  76  */
  77 struct audata {
  78   struct opaque_auth au_origcred;       /* original credentials */
  79   struct opaque_auth au_shcred; /* short hand cred */
  80   u_long au_shfaults;           /* short hand cache faults */
  81   char au_marshed[MAX_AUTH_BYTES];
  82   u_int au_mpos;                /* xdr pos at end of marshed */
  83 };
  84 #define AUTH_PRIVATE(auth)      ((struct audata *)auth->ah_private)
  85
  86 static bool_t marshal_new_auth (AUTH *) internal_function;
  87
  88
  89 /*
  90  * Create a unix style authenticator.
  91  * Returns an auth handle with the given stuff in it.
  92  */
  93 AUTH *
  94 authunix_create (char *machname, uid_t uid, gid_t gid, int len,
  95                  gid_t *aup_gids)
  96 {
  97   struct authunix_parms aup;
  98   char mymem[MAX_AUTH_BYTES];
  99   struct timeval now;
 100   XDR xdrs;
 101   AUTH *auth;
 102   struct audata *au;
 103
 104   /*
 105    * Allocate and set up auth handle
 106    */
 107   auth = (AUTH *) mem_alloc (sizeof (*auth));
 108   au = (struct audata *) mem_alloc (sizeof (*au));
 109   if (auth == NULL || au == NULL)
 110     {
 111 no_memory:
 112 #ifdef USE_IN_LIBIO
 113       if (_IO_fwide (stderr, 0) > 0)
 114         (void) __fwprintf (stderr, L"%s",
 115                            _("authunix_create: out of memory\n"));
 116       else
 117 #endif
 118         (void) fputs (_("authunix_create: out of memory\n"), stderr);
 119       mem_free (auth, sizeof (*auth));
 120       mem_free (au, sizeof (*au));
 121       return NULL;
 122     }
 123   auth->ah_ops = &auth_unix_ops;
 124   auth->ah_private = (caddr_t) au;
 125   auth->ah_verf = au->au_shcred = _null_auth;
 126   au->au_shfaults = 0;
 127
 128   /*
 129    * fill in param struct from the given params
 130    */
 131   (void) __gettimeofday (&now, (struct timezone *) 0);
 132   aup.aup_time = now.tv_sec;
 133   aup.aup_machname = machname;
 134   aup.aup_uid = uid;
 135   aup.aup_gid = gid;
 136   aup.aup_len = (u_int) len;
 137   aup.aup_gids = aup_gids;
 138
 139   /*
 140    * Serialize the parameters into origcred
 141    */
 142   INTUSE(xdrmem_create) (&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
 143   if (!INTUSE(xdr_authunix_parms) (&xdrs, &aup))
 144     abort ();
 145   au->au_origcred.oa_length = len = XDR_GETPOS (&xdrs);
 146   au->au_origcred.oa_flavor = AUTH_UNIX;
 147   au->au_origcred.oa_base = mem_alloc ((u_int) len);
 148   if (au->au_origcred.oa_base == NULL)
 149     goto no_memory;
 150   memcpy(au->au_origcred.oa_base, mymem, (u_int) len);
 151
 152   /*
 153    * set auth handle to reflect new cred.
 154    */
 155   auth->ah_cred = au->au_origcred;
 156   marshal_new_auth (auth);
 157   return auth;
 158 }
 159 INTDEF (authunix_create)
 160
 161 /*
 162  * Returns an auth handle with parameters determined by doing lots of
 163  * syscalls.
 164  */
 165 AUTH *
 166 authunix_create_default (void)
 167 {
 168   int len;
 169   char machname[MAX_MACHINE_NAME + 1];
 170   uid_t uid;
 171   gid_t gid;
 172   int max_nr_groups = __sysconf (_SC_NGROUPS_MAX);
 173   gid_t gids[max_nr_groups];
 174
 175   if (__gethostname (machname, MAX_MACHINE_NAME) == -1)
 176     abort ();
 177   machname[MAX_MACHINE_NAME] = 0;
 178   uid = __geteuid ();
 179   gid = __getegid ();
 180
 181   if ((len = __getgroups (max_nr_groups, gids)) < 0)
 182     abort ();
 183   /* This braindamaged Sun code forces us here to truncate the
 184      list of groups to NGRPS members since the code in
 185      authuxprot.c transforms a fixed array.  Grrr.  */
 186   return INTUSE(authunix_create) (machname, uid, gid, MIN (NGRPS, len), gids);
 187 }
 188 INTDEF (authunix_create_default)
 189
 190 /*
 191  * authunix operations
 192  */
 193
 194 static void
 195 authunix_nextverf (AUTH *auth)
 196 {
 197   /* no action necessary */
 198 }
 199
 200 static bool_t
 201 authunix_marshal (AUTH *auth, XDR *xdrs)
 202 {
 203   struct audata *au = AUTH_PRIVATE (auth);
 204
 205   return XDR_PUTBYTES (xdrs, au->au_marshed, au->au_mpos);
 206 }
 207
 208 static bool_t
 209 authunix_validate (AUTH *auth, struct opaque_auth *verf)
 210 {
 211   struct audata *au;
 212   XDR xdrs;
 213
 214   if (verf->oa_flavor == AUTH_SHORT)
 215     {
 216       au = AUTH_PRIVATE (auth);
 217       INTUSE(xdrmem_create) (&xdrs, verf->oa_base, verf->oa_length,
 218                              XDR_DECODE);
 219
 220       if (au->au_shcred.oa_base != NULL)
 221         {
 222           mem_free (au->au_shcred.oa_base,
 223                     au->au_shcred.oa_length);
 224           au->au_shcred.oa_base = NULL;
 225         }
 226       if (INTUSE(xdr_opaque_auth) (&xdrs, &au->au_shcred))
 227         {
 228           auth->ah_cred = au->au_shcred;
 229         }
 230       else
 231         {
 232           xdrs.x_op = XDR_FREE;
 233           (void) INTUSE(xdr_opaque_auth) (&xdrs, &au->au_shcred);
 234           au->au_shcred.oa_base = NULL;
 235           auth->ah_cred = au->au_origcred;
 236         }
 237       marshal_new_auth (auth);
 238     }
 239   return TRUE;
 240 }
 241
 242 static bool_t
 243 authunix_refresh (AUTH *auth)
 244 {
 245   struct audata *au = AUTH_PRIVATE (auth);
 246   struct authunix_parms aup;
 247   struct timeval now;
 248   XDR xdrs;
 249   int stat;
 250
 251   if (auth->ah_cred.oa_base == au->au_origcred.oa_base)
 252     {
 253       /* there is no hope.  Punt */
 254       return FALSE;
 255     }
 256   au->au_shfaults++;
 257
 258   /* first deserialize the creds back into a struct authunix_parms */
 259   aup.aup_machname = NULL;
 260   aup.aup_gids = (gid_t *) NULL;
 261   INTUSE(xdrmem_create) (&xdrs, au->au_origcred.oa_base,
 262                          au->au_origcred.oa_length, XDR_DECODE);
 263   stat = INTUSE(xdr_authunix_parms) (&xdrs, &aup);
 264   if (!stat)
 265     goto done;
 266
 267   /* update the time and serialize in place */
 268   (void) __gettimeofday (&now, (struct timezone *) 0);
 269   aup.aup_time = now.tv_sec;
 270   xdrs.x_op = XDR_ENCODE;
 271   XDR_SETPOS (&xdrs, 0);
 272   stat = INTUSE(xdr_authunix_parms) (&xdrs, &aup);
 273   if (!stat)
 274     goto done;
 275   auth->ah_cred = au->au_origcred;
 276   marshal_new_auth (auth);
 277 done:
 278   /* free the struct authunix_parms created by deserializing */
 279   xdrs.x_op = XDR_FREE;
 280   (void) INTUSE(xdr_authunix_parms) (&xdrs, &aup);
 281   XDR_DESTROY (&xdrs);
 282   return stat;
 283 }
 284
 285 static void
 286 authunix_destroy (AUTH *auth)
 287 {
 288   struct audata *au = AUTH_PRIVATE (auth);
 289
 290   mem_free (au->au_origcred.oa_base, au->au_origcred.oa_length);
 291
 292   if (au->au_shcred.oa_base != NULL)
 293     mem_free (au->au_shcred.oa_base, au->au_shcred.oa_length);
 294
 295   mem_free (auth->ah_private, sizeof (struct audata));
 296
 297   if (auth->ah_verf.oa_base != NULL)
 298     mem_free (auth->ah_verf.oa_base, auth->ah_verf.oa_length);
 299
 300   mem_free ((caddr_t) auth, sizeof (*auth));
 301 }
 302
 303 /*
 304  * Marshals (pre-serializes) an auth struct.
 305  * sets private data, au_marshed and au_mpos
 306  */
 307 static bool_t
 308 internal_function
 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   INTUSE(xdrmem_create) (xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
 316   if ((!INTUSE(xdr_opaque_auth) (xdrs, &(auth->ah_cred))) ||
 317       (!INTUSE(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   return TRUE;
 325 }