auth_unix.c

   1 /*
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   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 #define __FORCE_GLIBC
  42 #include <features.h>
  43
  44 #include <limits.h>
  45 #include <stdio.h>
  46 #include <string.h>
  47 #include <unistd.h>
  48 #include <sys/param.h>
  49
  50 #include <rpc/types.h>
  51 #include <rpc/xdr.h>
  52 #include <rpc/auth.h>
  53 #include <rpc/auth_unix.h>
  54
  55 #ifdef USE_IN_LIBIO
  56 # include <wchar.h>
  57 #endif
  58
  59 /*
  60  * Unix authenticator operations vector
  61  */
  62 static void authunix_nextverf (AUTH *);
  63 static bool_t authunix_marshal (AUTH *, XDR *);
  64 static bool_t authunix_validate (AUTH *, struct opaque_auth *);
  65 static bool_t authunix_refresh (AUTH *);
  66 static void authunix_destroy (AUTH *);
  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 };
  75
  76 /*
  77  * This struct is pointed to by the ah_private field of an auth_handle.
  78  */
  79 struct audata {
  80   struct opaque_auth au_origcred;       /* original credentials */
  81   struct opaque_auth au_shcred; /* short hand cred */
  82   u_long au_shfaults;           /* short hand cache faults */
  83   char au_marshed[MAX_AUTH_BYTES];
  84   u_int au_mpos;                /* xdr pos at end of marshed */
  85 };
  86 #define AUTH_PRIVATE(auth)      ((struct audata *)auth->ah_private)
  87
  88 static bool_t marshal_new_auth (AUTH *) internal_function;
  89
  90
  91 /*
  92  * Create a unix style authenticator.
  93  * Returns an auth handle with the given stuff in it.
  94  */
  95 AUTH *
  96 authunix_create (char *machname, uid_t uid, gid_t gid, int len,
  97                  gid_t *aup_gids)
  98 {
  99   struct authunix_parms aup;
 100   char mymem[MAX_AUTH_BYTES];
 101   struct timeval now;
 102   XDR xdrs;
 103   AUTH *auth;
 104   struct audata *au;
 105
 106   /*
 107    * Allocate and set up auth handle
 108    */
 109   auth = (AUTH *) mem_alloc (sizeof (*auth));
 110   au = (struct audata *) mem_alloc (sizeof (*au));
 111   if (auth == NULL || au == NULL)
 112     {
 113 no_memory:
 114 #ifdef USE_IN_LIBIO
 115       if (_IO_fwide (stderr, 0) > 0)
 116         (void) fwprintf (stderr, L"%s",
 117                            _("authunix_create: out of memory\n"));
 118       else
 119 #endif
 120         (void) fputs (_("authunix_create: out of memory\n"), stderr);
 121       mem_free (auth, sizeof (*auth));
 122       mem_free (au, sizeof (*au));
 123       return NULL;
 124     }
 125   auth->ah_ops = &auth_unix_ops;
 126   auth->ah_private = (caddr_t) au;
 127   auth->ah_verf = au->au_shcred = _null_auth;
 128   au->au_shfaults = 0;
 129
 130   /*
 131    * fill in param struct from the given params
 132    */
 133   (void) gettimeofday (&now, (struct timezone *) 0);
 134   aup.aup_time = now.tv_sec;
 135   aup.aup_machname = machname;
 136   aup.aup_uid = uid;
 137   aup.aup_gid = gid;
 138   aup.aup_len = (u_int) len;
 139   aup.aup_gids = aup_gids;
 140
 141   /*
 142    * Serialize the parameters into origcred
 143    */
 144   xdrmem_create (&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
 145   if (!xdr_authunix_parms (&xdrs, &aup))
 146     abort ();
 147   au->au_origcred.oa_length = len = XDR_GETPOS (&xdrs);
 148   au->au_origcred.oa_flavor = AUTH_UNIX;
 149   au->au_origcred.oa_base = mem_alloc ((u_int) len);
 150   if (au->au_origcred.oa_base == NULL)
 151     goto no_memory;
 152   memcpy(au->au_origcred.oa_base, mymem, (u_int) len);
 153
 154   /*
 155    * set auth handle to reflect new cred.
 156    */
 157   auth->ah_cred = au->au_origcred;
 158   marshal_new_auth (auth);
 159   return auth;
 160 }
 161 libc_hidden_def(authunix_create)
 162
 163 /*
 164  * Returns an auth handle with parameters determined by doing lots of
 165  * syscalls.
 166  */
 167 AUTH *
 168 authunix_create_default (void)
 169 {
 170   int len;
 171   char machname[MAX_MACHINE_NAME + 1];
 172   uid_t uid;
 173   gid_t gid;
 174   int max_nr_groups = sysconf (_SC_NGROUPS_MAX);
 175   gid_t *gids = NULL;
 176   AUTH *ret_auth;
 177
 178   if (max_nr_groups) {
 179     gids = (gid_t*)malloc(sizeof(*gids) * max_nr_groups);
 180     if (gids == NULL)
 181       abort ();
 182   }
 183
 184   if (gethostname (machname, MAX_MACHINE_NAME) == -1)
 185     abort ();
 186   machname[MAX_MACHINE_NAME] = 0;
 187   uid = geteuid ();
 188   gid = getegid ();
 189
 190   if ((len = getgroups (max_nr_groups, gids)) < 0)
 191     abort ();
 192   /* This braindamaged Sun code forces us here to truncate the
 193      list of groups to NGRPS members since the code in
 194      authuxprot.c transforms a fixed array.  Grrr.  */
 195   ret_auth = authunix_create (machname, uid, gid, MIN (NGRPS, len), gids);
 196   free (gids);
 197   return ret_auth;
 198 }
 199 libc_hidden_def(authunix_create_default)
 200
 201 /*
 202  * authunix operations
 203  */
 204
 205 static void
 206 authunix_nextverf (AUTH *auth attribute_unused)
 207 {
 208   /* no action necessary */
 209 }
 210
 211 static bool_t
 212 authunix_marshal (AUTH *auth, XDR *xdrs)
 213 {
 214   struct audata *au = AUTH_PRIVATE (auth);
 215
 216   return XDR_PUTBYTES (xdrs, au->au_marshed, au->au_mpos);
 217 }
 218
 219 static bool_t
 220 authunix_validate (AUTH *auth, struct opaque_auth *verf)
 221 {
 222   struct audata *au;
 223   XDR xdrs;
 224
 225   if (verf->oa_flavor == AUTH_SHORT)
 226     {
 227       au = AUTH_PRIVATE (auth);
 228       xdrmem_create (&xdrs, verf->oa_base, verf->oa_length,
 229                      XDR_DECODE);
 230
 231       if (au->au_shcred.oa_base != NULL)
 232         {
 233           mem_free (au->au_shcred.oa_base,
 234                     au->au_shcred.oa_length);
 235           au->au_shcred.oa_base = NULL;
 236         }
 237       if (xdr_opaque_auth (&xdrs, &au->au_shcred))
 238         {
 239           auth->ah_cred = au->au_shcred;
 240         }
 241       else
 242         {
 243           xdrs.x_op = XDR_FREE;
 244           (void) xdr_opaque_auth (&xdrs, &au->au_shcred);
 245           au->au_shcred.oa_base = NULL;
 246           auth->ah_cred = au->au_origcred;
 247         }
 248       marshal_new_auth (auth);
 249     }
 250   return TRUE;
 251 }
 252
 253 static bool_t
 254 authunix_refresh (AUTH *auth)
 255 {
 256   struct audata *au = AUTH_PRIVATE (auth);
 257   struct authunix_parms aup;
 258   struct timeval now;
 259   XDR xdrs;
 260   int stat;
 261
 262   if (auth->ah_cred.oa_base == au->au_origcred.oa_base)
 263     {
 264       /* there is no hope.  Punt */
 265       return FALSE;
 266     }
 267   au->au_shfaults++;
 268
 269   /* first deserialize the creds back into a struct authunix_parms */
 270   aup.aup_machname = NULL;
 271   aup.aup_gids = (gid_t *) NULL;
 272   xdrmem_create (&xdrs, au->au_origcred.oa_base,
 273                  au->au_origcred.oa_length, XDR_DECODE);
 274   stat = xdr_authunix_parms (&xdrs, &aup);
 275   if (!stat)
 276     goto done;
 277
 278   /* update the time and serialize in place */
 279   (void) gettimeofday (&now, (struct timezone *) 0);
 280   aup.aup_time = now.tv_sec;
 281   xdrs.x_op = XDR_ENCODE;
 282   XDR_SETPOS (&xdrs, 0);
 283   stat = xdr_authunix_parms (&xdrs, &aup);
 284   if (!stat)
 285     goto done;
 286   auth->ah_cred = au->au_origcred;
 287   marshal_new_auth (auth);
 288 done:
 289   /* free the struct authunix_parms created by deserializing */
 290   xdrs.x_op = XDR_FREE;
 291   (void) xdr_authunix_parms (&xdrs, &aup);
 292   XDR_DESTROY (&xdrs);
 293   return stat;
 294 }
 295
 296 static void
 297 authunix_destroy (AUTH *auth)
 298 {
 299   struct audata *au = AUTH_PRIVATE (auth);
 300
 301   mem_free (au->au_origcred.oa_base, au->au_origcred.oa_length);
 302
 303   if (au->au_shcred.oa_base != NULL)
 304     mem_free (au->au_shcred.oa_base, au->au_shcred.oa_length);
 305
 306   mem_free (auth->ah_private, sizeof (struct audata));
 307
 308   if (auth->ah_verf.oa_base != NULL)
 309     mem_free (auth->ah_verf.oa_base, auth->ah_verf.oa_length);
 310
 311   mem_free ((caddr_t) auth, sizeof (*auth));
 312 }
 313
 314 /*
 315  * Marshals (pre-serializes) an auth struct.
 316  * sets private data, au_marshed and au_mpos
 317  */
 318 static bool_t
 319 internal_function
 320 marshal_new_auth (AUTH *auth)
 321 {
 322   XDR xdr_stream;
 323   XDR *xdrs = &xdr_stream;
 324   struct audata *au = AUTH_PRIVATE (auth);
 325
 326   xdrmem_create (xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
 327   if ((!xdr_opaque_auth (xdrs, &(auth->ah_cred))) ||
 328       (!xdr_opaque_auth (xdrs, &(auth->ah_verf))))
 329     perror (_("auth_none.c - Fatal marshalling problem"));
 330   else
 331     au->au_mpos = XDR_GETPOS (xdrs);
 332
 333   XDR_DESTROY (xdrs);
 334
 335   return TRUE;
 336 }