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   xdrmem_create (&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
 143   if (!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
 160 /*
 161  * Returns an auth handle with parameters determined by doing lots of
 162  * syscalls.
 163  */
 164 AUTH *
 165 authunix_create_default (void)
 166 {
 167   int len;
 168   char machname[MAX_MACHINE_NAME + 1];
 169   uid_t uid;
 170   gid_t gid;
 171   int max_nr_groups = __sysconf (_SC_NGROUPS_MAX);
 172   gid_t gids[max_nr_groups];
 173
 174   if (__gethostname (machname, MAX_MACHINE_NAME) == -1)
 175     abort ();
 176   machname[MAX_MACHINE_NAME] = 0;
 177   uid = __geteuid ();
 178   gid = __getegid ();
 179
 180   if ((len = __getgroups (max_nr_groups, gids)) < 0)
 181     abort ();
 182   /* This braindamaged Sun code forces us here to truncate the
 183      list of groups to NGRPS members since the code in
 184      authuxprot.c transforms a fixed array.  Grrr.  */
 185   return authunix_create (machname, uid, gid, MIN (NGRPS, len), gids);
 186 }
 187
 188 /*
 189  * authunix operations
 190  */
 191
 192 static void
 193 authunix_nextverf (AUTH *auth)
 194 {
 195   /* no action necessary */
 196 }
 197
 198 static bool_t
 199 authunix_marshal (AUTH *auth, XDR *xdrs)
 200 {
 201   struct audata *au = AUTH_PRIVATE (auth);
 202
 203   return XDR_PUTBYTES (xdrs, au->au_marshed, au->au_mpos);
 204 }
 205
 206 static bool_t
 207 authunix_validate (AUTH *auth, struct opaque_auth *verf)
 208 {
 209   struct audata *au;
 210   XDR xdrs;
 211
 212   if (verf->oa_flavor == AUTH_SHORT)
 213     {
 214       au = AUTH_PRIVATE (auth);
 215       xdrmem_create (&xdrs, verf->oa_base, verf->oa_length,
 216                      XDR_DECODE);
 217
 218       if (au->au_shcred.oa_base != NULL)
 219         {
 220           mem_free (au->au_shcred.oa_base,
 221                     au->au_shcred.oa_length);
 222           au->au_shcred.oa_base = NULL;
 223         }
 224       if (xdr_opaque_auth (&xdrs, &au->au_shcred))
 225         {
 226           auth->ah_cred = au->au_shcred;
 227         }
 228       else
 229         {
 230           xdrs.x_op = XDR_FREE;
 231           (void) xdr_opaque_auth (&xdrs, &au->au_shcred);
 232           au->au_shcred.oa_base = NULL;
 233           auth->ah_cred = au->au_origcred;
 234         }
 235       marshal_new_auth (auth);
 236     }
 237   return TRUE;
 238 }
 239
 240 static bool_t
 241 authunix_refresh (AUTH *auth)
 242 {
 243   struct audata *au = AUTH_PRIVATE (auth);
 244   struct authunix_parms aup;
 245   struct timeval now;
 246   XDR xdrs;
 247   int stat;
 248
 249   if (auth->ah_cred.oa_base == au->au_origcred.oa_base)
 250     {
 251       /* there is no hope.  Punt */
 252       return FALSE;
 253     }
 254   au->au_shfaults++;
 255
 256   /* first deserialize the creds back into a struct authunix_parms */
 257   aup.aup_machname = NULL;
 258   aup.aup_gids = (gid_t *) NULL;
 259   xdrmem_create (&xdrs, au->au_origcred.oa_base,
 260                  au->au_origcred.oa_length, XDR_DECODE);
 261   stat = xdr_authunix_parms (&xdrs, &aup);
 262   if (!stat)
 263     goto done;
 264
 265   /* update the time and serialize in place */
 266   (void) __gettimeofday (&now, (struct timezone *) 0);
 267   aup.aup_time = now.tv_sec;
 268   xdrs.x_op = XDR_ENCODE;
 269   XDR_SETPOS (&xdrs, 0);
 270   stat = xdr_authunix_parms (&xdrs, &aup);
 271   if (!stat)
 272     goto done;
 273   auth->ah_cred = au->au_origcred;
 274   marshal_new_auth (auth);
 275 done:
 276   /* free the struct authunix_parms created by deserializing */
 277   xdrs.x_op = XDR_FREE;
 278   (void) xdr_authunix_parms (&xdrs, &aup);
 279   XDR_DESTROY (&xdrs);
 280   return stat;
 281 }
 282
 283 static void
 284 authunix_destroy (AUTH *auth)
 285 {
 286   struct audata *au = AUTH_PRIVATE (auth);
 287
 288   mem_free (au->au_origcred.oa_base, au->au_origcred.oa_length);
 289
 290   if (au->au_shcred.oa_base != NULL)
 291     mem_free (au->au_shcred.oa_base, au->au_shcred.oa_length);
 292
 293   mem_free (auth->ah_private, sizeof (struct audata));
 294
 295   if (auth->ah_verf.oa_base != NULL)
 296     mem_free (auth->ah_verf.oa_base, auth->ah_verf.oa_length);
 297
 298   mem_free ((caddr_t) auth, sizeof (*auth));
 299 }
 300
 301 /*
 302  * Marshals (pre-serializes) an auth struct.
 303  * sets private data, au_marshed and au_mpos
 304  */
 305 static bool_t
 306 internal_function
 307 marshal_new_auth (AUTH *auth)
 308 {
 309   XDR xdr_stream;
 310   XDR *xdrs = &xdr_stream;
 311   struct audata *au = AUTH_PRIVATE (auth);
 312
 313   xdrmem_create (xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
 314   if ((!xdr_opaque_auth (xdrs, &(auth->ah_cred))) ||
 315       (!xdr_opaque_auth (xdrs, &(auth->ah_verf))))
 316     perror (_("auth_none.c - Fatal marshalling problem"));
 317   else
 318     au->au_mpos = XDR_GETPOS (xdrs);
 319
 320   XDR_DESTROY (xdrs);
 321
 322   return TRUE;
 323 }