lib/libc/rpc/auth_unix.c

   1 /*      $NetBSD: auth_unix.c,v 1.23 2012/03/20 17:14:50 matt 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 1.23 2012/03/20 17:14:50 matt 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(AUTH *);
  78 static bool_t authunix_marshal(AUTH *, XDR *);
  79 static bool_t authunix_validate(AUTH *, struct opaque_auth *);
  80 static bool_t authunix_refresh(AUTH *);
  81 static void authunix_destroy(AUTH *);
  82 static void marshal_new_auth(AUTH *);
  83 static const struct auth_ops *authunix_ops(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(char *machname, int uid, int gid, int len, int *aup_gids)
 103 {
 104         struct authunix_parms aup;
 105         char mymem[MAX_AUTH_BYTES];
 106         struct timeval now;
 107         XDR xdrs;
 108         AUTH *auth;
 109         struct audata *au;
 110
 111         /*
 112          * Allocate and set up auth handle
 113          */
 114         au = NULL;
 115         auth = mem_alloc(sizeof(*auth));
 116 #ifndef KERNEL
 117         if (auth == NULL) {
 118                 warnx("authunix_create: out of memory");
 119                 goto cleanup_authunix_create;
 120         }
 121 #endif
 122         au = mem_alloc(sizeof(*au));
 123 #ifndef KERNEL
 124         if (au == NULL) {
 125                 warnx("authunix_create: out of memory");
 126                 goto cleanup_authunix_create;
 127         }
 128 #endif
 129         auth->ah_ops = authunix_ops();
 130         auth->ah_private = au;
 131         auth->ah_verf = au->au_shcred = _null_auth;
 132         au->au_shfaults = 0;
 133         au->au_origcred.oa_base = NULL;
 134
 135         /*
 136          * fill in param struct from the given params
 137          */
 138         (void)gettimeofday(&now, NULL);
 139         aup.aup_time = (u_long)now.tv_sec;      /* XXX: truncate on 32 bit */
 140         aup.aup_machname = machname;
 141         aup.aup_uid = uid;
 142         aup.aup_gid = gid;
 143         aup.aup_len = (u_int)len;
 144         aup.aup_gids = aup_gids;
 145
 146         /*
 147          * Serialize the parameters into origcred
 148          */
 149         xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
 150         if (! xdr_authunix_parms(&xdrs, &aup))
 151                 abort();
 152         au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
 153         au->au_origcred.oa_flavor = AUTH_UNIX;
 154 #ifdef KERNEL
 155         au->au_origcred.oa_base = mem_alloc((size_t)len);
 156 #else
 157         if ((au->au_origcred.oa_base = mem_alloc((size_t)len)) == NULL) {
 158                 warnx("authunix_create: out of memory");
 159                 goto cleanup_authunix_create;
 160         }
 161 #endif
 162         memmove(au->au_origcred.oa_base, mymem, (size_t)len);
 163
 164         /*
 165          * set auth handle to reflect new cred.
 166          */
 167         auth->ah_cred = au->au_origcred;
 168         marshal_new_auth(auth);
 169         return (auth);
 170 #ifndef KERNEL
 171  cleanup_authunix_create:
 172         if (auth)
 173                 mem_free(auth, sizeof(*auth));
 174         if (au) {
 175                 if (au->au_origcred.oa_base)
 176                         mem_free(au->au_origcred.oa_base, (u_int)len);
 177                 mem_free(au, sizeof(*au));
 178         }
 179         return (NULL);
 180 #endif
 181 }
 182
 183 /*
 184  * Returns an auth handle with parameters determined by doing lots of
 185  * syscalls.
 186  */
 187 AUTH *
 188 authunix_create_default(void)
 189 {
 190         int len;
 191         char machname[MAXHOSTNAMELEN + 1];
 192         uid_t uid;
 193         gid_t gid;
 194         gid_t gids[NGRPS];
 195
 196         if (gethostname(machname, sizeof machname) == -1)
 197                 abort();
 198         machname[sizeof(machname) - 1] = 0;
 199         uid = geteuid();
 200         gid = getegid();
 201         if ((len = getgroups(NGRPS, gids)) < 0)
 202                 abort();
 203         /* XXX: interface problem; those should all have been unsigned */
 204         return (authunix_create(machname, (int)uid, (int)gid, len,
 205             (int *)gids));
 206 }
 207
 208 /*
 209  * authunix operations
 210  */
 211
 212 /* ARGSUSED */
 213 static void
 214 authunix_nextverf(AUTH *auth)
 215 {
 216         /* no action necessary */
 217 }
 218
 219 static bool_t
 220 authunix_marshal(AUTH *auth, XDR *xdrs)
 221 {
 222         struct audata *au;
 223
 224         _DIAGASSERT(auth != NULL);
 225         _DIAGASSERT(xdrs != NULL);
 226
 227         au = AUTH_PRIVATE(auth);
 228         return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
 229 }
 230
 231 static bool_t
 232 authunix_validate(AUTH *auth, struct opaque_auth *verf)
 233 {
 234         struct audata *au;
 235         XDR xdrs;
 236
 237         _DIAGASSERT(auth != NULL);
 238         _DIAGASSERT(verf != NULL);
 239
 240         if (verf->oa_flavor == AUTH_SHORT) {
 241                 au = AUTH_PRIVATE(auth);
 242                 xdrmem_create(&xdrs, verf->oa_base, verf->oa_length,
 243                     XDR_DECODE);
 244
 245                 if (au->au_shcred.oa_base != NULL) {
 246                         mem_free(au->au_shcred.oa_base,
 247                             au->au_shcred.oa_length);
 248                         au->au_shcred.oa_base = NULL;
 249                 }
 250                 if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
 251                         auth->ah_cred = au->au_shcred;
 252                 } else {
 253                         xdrs.x_op = XDR_FREE;
 254                         (void)xdr_opaque_auth(&xdrs, &au->au_shcred);
 255                         au->au_shcred.oa_base = NULL;
 256                         auth->ah_cred = au->au_origcred;
 257                 }
 258                 marshal_new_auth(auth);
 259         }
 260         return (TRUE);
 261 }
 262
 263 static bool_t
 264 authunix_refresh(AUTH *auth)
 265 {
 266         struct audata *au = AUTH_PRIVATE(auth);
 267         struct authunix_parms aup;
 268         struct timeval now;
 269         XDR xdrs;
 270         int stat;
 271
 272         _DIAGASSERT(auth != NULL);
 273
 274         if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
 275                 /* there is no hope.  Punt */
 276                 return (FALSE);
 277         }
 278         au->au_shfaults++;
 279
 280         /* first deserialize the creds back into a struct authunix_parms */
 281         aup.aup_machname = NULL;
 282         aup.aup_gids = NULL;
 283         xdrmem_create(&xdrs, au->au_origcred.oa_base,
 284             au->au_origcred.oa_length, XDR_DECODE);
 285         stat = xdr_authunix_parms(&xdrs, &aup);
 286         if (! stat)
 287                 goto done;
 288
 289         /* update the time and serialize in place */
 290         (void)gettimeofday(&now, NULL);
 291         aup.aup_time = (u_long)now.tv_sec;      /* XXX: truncate on 32 bit */
 292         xdrs.x_op = XDR_ENCODE;
 293         XDR_SETPOS(&xdrs, 0);
 294         stat = xdr_authunix_parms(&xdrs, &aup);
 295         if (! stat)
 296                 goto done;
 297         auth->ah_cred = au->au_origcred;
 298         marshal_new_auth(auth);
 299 done:
 300         /* free the struct authunix_parms created by deserializing */
 301         xdrs.x_op = XDR_FREE;
 302         (void)xdr_authunix_parms(&xdrs, &aup);
 303         XDR_DESTROY(&xdrs);
 304         return (stat);
 305 }
 306
 307 static void
 308 authunix_destroy(AUTH *auth)
 309 {
 310         struct audata *au;
 311
 312         _DIAGASSERT(auth != NULL);
 313
 314         au = AUTH_PRIVATE(auth);
 315         mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);
 316
 317         if (au->au_shcred.oa_base != NULL)
 318                 mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);
 319
 320         mem_free(auth->ah_private, sizeof(struct audata));
 321
 322         if (auth->ah_verf.oa_base != NULL)
 323                 mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);
 324
 325         mem_free(auth, sizeof(*auth));
 326 }
 327
 328 /*
 329  * Marshals (pre-serializes) an auth struct.
 330  * sets private data, au_marshed and au_mpos
 331  */
 332 static void
 333 marshal_new_auth(AUTH *auth)
 334 {
 335         XDR     xdr_stream;
 336         XDR     *xdrs = &xdr_stream;
 337         struct audata *au;
 338
 339         _DIAGASSERT(auth != NULL);
 340
 341         au = AUTH_PRIVATE(auth);
 342         xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
 343         if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
 344             (! xdr_opaque_auth(xdrs, &(auth->ah_verf))))
 345                 warnx("auth_none.c - Fatal marshalling problem");
 346         else
 347                 au->au_mpos = XDR_GETPOS(xdrs);
 348         XDR_DESTROY(xdrs);
 349 }
 350
 351 static const struct auth_ops *
 352 authunix_ops(void)
 353 {
 354         static struct auth_ops ops;
 355 #ifdef _REENTRANT
 356         extern mutex_t ops_lock;
 357 #endif
 358
 359         /* VARIABLES PROTECTED BY ops_lock: ops */
 360
 361         mutex_lock(&ops_lock);
 362         if (ops.ah_nextverf == NULL) {
 363                 ops.ah_nextverf = authunix_nextverf;
 364                 ops.ah_marshal = authunix_marshal;
 365                 ops.ah_validate = authunix_validate;
 366                 ops.ah_refresh = authunix_refresh;
 367                 ops.ah_destroy = authunix_destroy;
 368         }
 369         mutex_unlock(&ops_lock);
 370         return (&ops);
 371 }