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 /*
  54  * Unix authenticator operations vector
  55  */
  56 static void authunix_nextverf (AUTH *);
  57 static bool_t authunix_marshal (AUTH *, XDR *);
  58 static bool_t authunix_validate (AUTH *, struct opaque_auth *);
  59 static bool_t authunix_refresh (AUTH *);
  60 static void authunix_destroy (AUTH *);
  61
  62 static struct auth_ops auth_unix_ops = {
  63   authunix_nextverf,
  64   authunix_marshal,
  65   authunix_validate,
  66   authunix_refresh,
  67   authunix_destroy
  68 };
  69
  70 /*
  71  * This struct is pointed to by the ah_private field of an auth_handle.
  72  */
  73 struct audata {
  74   struct opaque_auth au_origcred;       /* original credentials */
  75   struct opaque_auth au_shcred; /* short hand cred */
  76   u_long au_shfaults;           /* short hand cache faults */
  77   char au_marshed[MAX_AUTH_BYTES];
  78   u_int au_mpos;                /* xdr pos at end of marshed */
  79 };
  80 #define AUTH_PRIVATE(auth)      ((struct audata *)auth->ah_private)
  81
  82 static bool_t marshal_new_auth (AUTH *) internal_function;
  83
  84
  85 /*
  86  * Create a unix style authenticator.
  87  * Returns an auth handle with the given stuff in it.
  88  */
  89 AUTH *
  90 authunix_create (char *machname, uid_t uid, gid_t gid, int len,
  91                  gid_t *aup_gids)
  92 {
  93   struct authunix_parms aup;
  94   char mymem[MAX_AUTH_BYTES];
  95   struct timeval now;
  96   XDR xdrs;
  97   AUTH *auth;
  98   struct audata *au;
  99
 100   /*
 101    * Allocate and set up auth handle
 102    */
 103   auth = (AUTH *) mem_alloc (sizeof (*auth));
 104   if (auth == NULL)
 105     {
 106       (void) fprintf (stderr, _("authunix_create: out of memory\n"));
 107       return NULL;
 108     }
 109   au = (struct audata *) mem_alloc (sizeof (*au));
 110   if (au == NULL)
 111     {
 112       (void) fprintf (stderr, _("authunix_create: out of memory\n"));
 113       return NULL;
 114     }
 115   auth->ah_ops = &auth_unix_ops;
 116   auth->ah_private = (caddr_t) au;
 117   auth->ah_verf = au->au_shcred = _null_auth;
 118   au->au_shfaults = 0;
 119
 120   /*
 121    * fill in param struct from the given params
 122    */
 123   (void) __gettimeofday (&now, (struct timezone *) 0);
 124   aup.aup_time = now.tv_sec;
 125   aup.aup_machname = machname;
 126   aup.aup_uid = uid;
 127   aup.aup_gid = gid;
 128   aup.aup_len = (u_int) len;
 129   aup.aup_gids = aup_gids;
 130
 131   /*
 132    * Serialize the parameters into origcred
 133    */
 134   xdrmem_create (&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
 135   if (!xdr_authunix_parms (&xdrs, &aup))
 136     abort ();
 137   au->au_origcred.oa_length = len = XDR_GETPOS (&xdrs);
 138   au->au_origcred.oa_flavor = AUTH_UNIX;
 139   au->au_origcred.oa_base = mem_alloc ((u_int) len);
 140   if (au->au_origcred.oa_base == NULL)
 141     {
 142       (void) fputs (_("authunix_create: out of memory\n"), stderr);
 143       return NULL;
 144     }
 145   memcpy(au->au_origcred.oa_base, mymem, (u_int) len);
 146
 147   /*
 148    * set auth handle to reflect new cred.
 149    */
 150   auth->ah_cred = au->au_origcred;
 151   marshal_new_auth (auth);
 152   return auth;
 153 }
 154
 155 /*
 156  * Returns an auth handle with parameters determined by doing lots of
 157  * syscalls.
 158  */
 159 AUTH *
 160 authunix_create_default (void)
 161 {
 162   int len;
 163   char machname[MAX_MACHINE_NAME + 1];
 164   uid_t uid;
 165   gid_t gid;
 166   int max_nr_groups = __sysconf (_SC_NGROUPS_MAX);
 167   gid_t gids[max_nr_groups];
 168
 169   if (__gethostname (machname, MAX_MACHINE_NAME) == -1)
 170     abort ();
 171   machname[MAX_MACHINE_NAME] = 0;
 172   uid = __geteuid ();
 173   gid = __getegid ();
 174
 175   if ((len = __getgroups (max_nr_groups, gids)) < 0)
 176     abort ();
 177   /* This braindamaged Sun code forces us here to truncate the
 178      list of groups to NGRPS members since the code in
 179      authuxprot.c transforms a fixed array.  Grrr.  */
 180   return authunix_create (machname, uid, gid, MIN (NGRPS, len), gids);
 181 }
 182
 183 /*
 184  * authunix operations
 185  */
 186
 187 static void
 188 authunix_nextverf (AUTH *auth)
 189 {
 190   /* no action necessary */
 191 }
 192
 193 static bool_t
 194 authunix_marshal (AUTH *auth, XDR *xdrs)
 195 {
 196   struct audata *au = AUTH_PRIVATE (auth);
 197
 198   return XDR_PUTBYTES (xdrs, au->au_marshed, au->au_mpos);
 199 }
 200
 201 static bool_t
 202 authunix_validate (AUTH *auth, struct opaque_auth *verf)
 203 {
 204   struct audata *au;
 205   XDR xdrs;
 206
 207   if (verf->oa_flavor == AUTH_SHORT)
 208     {
 209       au = AUTH_PRIVATE (auth);
 210       xdrmem_create (&xdrs, verf->oa_base, verf->oa_length,
 211                      XDR_DECODE);
 212
 213       if (au->au_shcred.oa_base != NULL)
 214         {
 215           mem_free (au->au_shcred.oa_base,
 216                     au->au_shcred.oa_length);
 217           au->au_shcred.oa_base = NULL;
 218         }
 219       if (xdr_opaque_auth (&xdrs, &au->au_shcred))
 220         {
 221           auth->ah_cred = au->au_shcred;
 222         }
 223       else
 224         {
 225           xdrs.x_op = XDR_FREE;
 226           (void) xdr_opaque_auth (&xdrs, &au->au_shcred);
 227           au->au_shcred.oa_base = NULL;
 228           auth->ah_cred = au->au_origcred;
 229         }
 230       marshal_new_auth (auth);
 231     }
 232   return TRUE;
 233 }
 234
 235 static bool_t
 236 authunix_refresh (AUTH *auth)
 237 {
 238   struct audata *au = AUTH_PRIVATE (auth);
 239   struct authunix_parms aup;
 240   struct timeval now;
 241   XDR xdrs;
 242   int stat;
 243
 244   if (auth->ah_cred.oa_base == au->au_origcred.oa_base)
 245     {
 246       /* there is no hope.  Punt */
 247       return FALSE;
 248     }
 249   au->au_shfaults++;
 250
 251   /* first deserialize the creds back into a struct authunix_parms */
 252   aup.aup_machname = NULL;
 253   aup.aup_gids = (gid_t *) NULL;
 254   xdrmem_create (&xdrs, au->au_origcred.oa_base,
 255                  au->au_origcred.oa_length, XDR_DECODE);
 256   stat = xdr_authunix_parms (&xdrs, &aup);
 257   if (!stat)
 258     goto done;
 259
 260   /* update the time and serialize in place */
 261   (void) __gettimeofday (&now, (struct timezone *) 0);
 262   aup.aup_time = now.tv_sec;
 263   xdrs.x_op = XDR_ENCODE;
 264   XDR_SETPOS (&xdrs, 0);
 265   stat = xdr_authunix_parms (&xdrs, &aup);
 266   if (!stat)
 267     goto done;
 268   auth->ah_cred = au->au_origcred;
 269   marshal_new_auth (auth);
 270 done:
 271   /* free the struct authunix_parms created by deserializing */
 272   xdrs.x_op = XDR_FREE;
 273   (void) xdr_authunix_parms (&xdrs, &aup);
 274   XDR_DESTROY (&xdrs);
 275   return stat;
 276 }
 277
 278 static void
 279 authunix_destroy (AUTH *auth)
 280 {
 281   struct audata *au = AUTH_PRIVATE (auth);
 282
 283   mem_free (au->au_origcred.oa_base, au->au_origcred.oa_length);
 284
 285   if (au->au_shcred.oa_base != NULL)
 286     mem_free (au->au_shcred.oa_base, au->au_shcred.oa_length);
 287
 288   mem_free (auth->ah_private, sizeof (struct audata));
 289
 290   if (auth->ah_verf.oa_base != NULL)
 291     mem_free (auth->ah_verf.oa_base, auth->ah_verf.oa_length);
 292
 293   mem_free ((caddr_t) auth, sizeof (*auth));
 294 }
 295
 296 /*
 297  * Marshals (pre-serializes) an auth struct.
 298  * sets private data, au_marshed and au_mpos
 299  */
 300 static bool_t
 301 internal_function
 302 marshal_new_auth (AUTH *auth)
 303 {
 304   XDR xdr_stream;
 305   XDR *xdrs = &xdr_stream;
 306   struct audata *au = AUTH_PRIVATE (auth);
 307
 308   xdrmem_create (xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
 309   if ((!xdr_opaque_auth (xdrs, &(auth->ah_cred))) ||
 310       (!xdr_opaque_auth (xdrs, &(auth->ah_verf))))
 311     perror (_("auth_none.c - Fatal marshalling problem"));
 312   else
 313     au->au_mpos = XDR_GETPOS (xdrs);
 314
 315   XDR_DESTROY (xdrs);
 316
 317   return TRUE;
 318 }