sunrpc/key_call.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) 1988 by Sun Microsystems, Inc.
  31  */
  32 /*
  33  * The original source is from the RPCSRC 4.0 package from Sun Microsystems.
  34  * The Interface to keyserver protocoll 2, RPC over AF_UNIX and Linux/doors
  35  * was added by Thorsten Kukuk <kukuk@suse.de>
  36  * Since the Linux/doors project was stopped, I doubt that this code will
  37  * ever be useful <kukuk@suse.de>.
  38  */
  39
  40 #include <stdio.h>
  41 #include <errno.h>
  42 #include <fcntl.h>
  43 #include <signal.h>
  44 #include <unistd.h>
  45 #include <string.h>
  46 #include <rpc/rpc.h>
  47 #include <rpc/auth.h>
  48 #include <sys/wait.h>
  49 #include <sys/param.h>
  50 #include <sys/socket.h>
  51 #include <rpc/key_prot.h>
  52 #include <bits/libc-lock.h>
  53
  54 #ifdef HAVE_DOORS
  55 # include "door/door.h"
  56 #endif
  57
  58 #define KEY_TIMEOUT     5       /* per-try timeout in seconds */
  59 #define KEY_NRETRY      12      /* number of retries */
  60
  61 #define debug(msg)              /* turn off debugging */
  62
  63 #ifndef SO_PASSCRED
  64 extern int _openchild (const char *command, FILE **fto, FILE **ffrom);
  65 #endif
  66
  67 static int key_call (u_long, xdrproc_t xdr_arg, char *,
  68                      xdrproc_t xdr_rslt, char *) internal_function;
  69
  70 static const struct timeval trytimeout = {KEY_TIMEOUT, 0};
  71 static const struct timeval tottimeout = {KEY_TIMEOUT *KEY_NRETRY, 0};
  72
  73 int
  74 key_setsecret (char *secretkey)
  75 {
  76   keystatus status;
  77
  78   if (!key_call ((u_long) KEY_SET, (xdrproc_t) INTUSE(xdr_keybuf), secretkey,
  79                  (xdrproc_t) INTUSE(xdr_keystatus), (char *) &status))
  80     return -1;
  81   if (status != KEY_SUCCESS)
  82     {
  83       debug ("set status is nonzero");
  84       return -1;
  85     }
  86   return 0;
  87 }
  88
  89 /* key_secretkey_is_set() returns 1 if the keyserver has a secret key
  90  * stored for the caller's effective uid; it returns 0 otherwise
  91  *
  92  * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
  93  * be using it, because it allows them to get the user's secret key.
  94  */
  95 int
  96 key_secretkey_is_set (void)
  97 {
  98   struct key_netstres kres;
  99
 100   memset (&kres, 0, sizeof (kres));
 101   if (key_call ((u_long) KEY_NET_GET, (xdrproc_t) INTUSE(xdr_void),
 102                 (char *) NULL, (xdrproc_t) INTUSE(xdr_key_netstres),
 103                 (char *) &kres) &&
 104       (kres.status == KEY_SUCCESS) &&
 105       (kres.key_netstres_u.knet.st_priv_key[0] != 0))
 106     {
 107       /* avoid leaving secret key in memory */
 108       memset (kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
 109       return 1;
 110     }
 111   return 0;
 112 }
 113
 114 int
 115 key_encryptsession (char *remotename, des_block *deskey)
 116 {
 117   cryptkeyarg arg;
 118   cryptkeyres res;
 119
 120   arg.remotename = remotename;
 121   arg.deskey = *deskey;
 122   if (!key_call ((u_long) KEY_ENCRYPT, (xdrproc_t) INTUSE(xdr_cryptkeyarg),
 123                  (char *) &arg, (xdrproc_t) INTUSE(xdr_cryptkeyres),
 124                  (char *) &res))
 125     return -1;
 126
 127   if (res.status != KEY_SUCCESS)
 128     {
 129       debug ("encrypt status is nonzero");
 130       return -1;
 131     }
 132   *deskey = res.cryptkeyres_u.deskey;
 133   return 0;
 134 }
 135
 136 int
 137 key_decryptsession (char *remotename, des_block *deskey)
 138 {
 139   cryptkeyarg arg;
 140   cryptkeyres res;
 141
 142   arg.remotename = remotename;
 143   arg.deskey = *deskey;
 144   if (!key_call ((u_long) KEY_DECRYPT, (xdrproc_t) INTUSE(xdr_cryptkeyarg),
 145                  (char *) &arg, (xdrproc_t) INTUSE(xdr_cryptkeyres),
 146                  (char *) &res))
 147     return -1;
 148   if (res.status != KEY_SUCCESS)
 149     {
 150       debug ("decrypt status is nonzero");
 151       return -1;
 152     }
 153   *deskey = res.cryptkeyres_u.deskey;
 154   return 0;
 155 }
 156
 157 int
 158 key_encryptsession_pk (char *remotename, netobj *remotekey,
 159                        des_block *deskey)
 160 {
 161   cryptkeyarg2 arg;
 162   cryptkeyres res;
 163
 164   arg.remotename = remotename;
 165   arg.remotekey = *remotekey;
 166   arg.deskey = *deskey;
 167   if (!key_call ((u_long) KEY_ENCRYPT_PK, (xdrproc_t) INTUSE(xdr_cryptkeyarg2),
 168                  (char *) &arg, (xdrproc_t) INTUSE(xdr_cryptkeyres),
 169                  (char *) &res))
 170     return -1;
 171
 172   if (res.status != KEY_SUCCESS)
 173     {
 174       debug ("encrypt status is nonzero");
 175       return -1;
 176     }
 177   *deskey = res.cryptkeyres_u.deskey;
 178   return 0;
 179 }
 180 libc_hidden_def (key_encryptsession_pk)
 181
 182 int
 183 key_decryptsession_pk (char *remotename, netobj *remotekey,
 184                        des_block *deskey)
 185 {
 186   cryptkeyarg2 arg;
 187   cryptkeyres res;
 188
 189   arg.remotename = remotename;
 190   arg.remotekey = *remotekey;
 191   arg.deskey = *deskey;
 192   if (!key_call ((u_long) KEY_DECRYPT_PK, (xdrproc_t) INTUSE(xdr_cryptkeyarg2),
 193                  (char *) &arg, (xdrproc_t) INTUSE(xdr_cryptkeyres),
 194                  (char *) &res))
 195     return -1;
 196
 197   if (res.status != KEY_SUCCESS)
 198     {
 199       debug ("decrypt status is nonzero");
 200       return -1;
 201     }
 202   *deskey = res.cryptkeyres_u.deskey;
 203   return 0;
 204 }
 205 libc_hidden_def (key_decryptsession_pk)
 206
 207 int
 208 key_gendes (des_block *key)
 209 {
 210   struct sockaddr_in sin;
 211   CLIENT *client;
 212   int socket;
 213   enum clnt_stat stat;
 214
 215   sin.sin_family = AF_INET;
 216   sin.sin_port = 0;
 217   sin.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
 218   __bzero (sin.sin_zero, sizeof (sin.sin_zero));
 219   socket = RPC_ANYSOCK;
 220   client = INTUSE(clntudp_bufcreate) (&sin, (u_long) KEY_PROG,
 221                                       (u_long) KEY_VERS, trytimeout, &socket,
 222                                       RPCSMALLMSGSIZE, RPCSMALLMSGSIZE);
 223   if (client == NULL)
 224     return -1;
 225
 226   stat = clnt_call (client, KEY_GEN, (xdrproc_t) INTUSE(xdr_void), NULL,
 227                     (xdrproc_t) INTUSE(xdr_des_block), (caddr_t) key,
 228                     tottimeout);
 229   clnt_destroy (client);
 230   __close (socket);
 231   if (stat != RPC_SUCCESS)
 232     return -1;
 233
 234   return 0;
 235 }
 236 libc_hidden_def (key_gendes)
 237
 238 int
 239 key_setnet (struct key_netstarg *arg)
 240 {
 241   keystatus status;
 242
 243   if (!key_call ((u_long) KEY_NET_PUT, (xdrproc_t) INTUSE(xdr_key_netstarg),
 244                  (char *) arg,(xdrproc_t) INTUSE(xdr_keystatus),
 245                  (char *) &status))
 246     return -1;
 247
 248   if (status != KEY_SUCCESS)
 249     {
 250       debug ("key_setnet status is nonzero");
 251       return -1;
 252     }
 253   return 1;
 254 }
 255
 256 int
 257 key_get_conv (char *pkey, des_block *deskey)
 258 {
 259   cryptkeyres res;
 260
 261   if (!key_call ((u_long) KEY_GET_CONV, (xdrproc_t) INTUSE(xdr_keybuf), pkey,
 262                  (xdrproc_t) INTUSE(xdr_cryptkeyres), (char *) &res))
 263     return -1;
 264
 265   if (res.status != KEY_SUCCESS)
 266     {
 267       debug ("get_conv status is nonzero");
 268       return -1;
 269     }
 270   *deskey = res.cryptkeyres_u.deskey;
 271   return 0;
 272 }
 273
 274 /*
 275  * Hack to allow the keyserver to use AUTH_DES (for authenticated
 276  * NIS+ calls, for example).  The only functions that get called
 277  * are key_encryptsession_pk, key_decryptsession_pk, and key_gendes.
 278  *
 279  * The approach is to have the keyserver fill in pointers to local
 280  * implementations of these functions, and to call those in key_call().
 281  */
 282
 283 cryptkeyres *(*__key_encryptsession_pk_LOCAL) (uid_t, char *);
 284 cryptkeyres *(*__key_decryptsession_pk_LOCAL) (uid_t, char *);
 285 des_block *(*__key_gendes_LOCAL) (uid_t, char *);
 286
 287 #ifndef SO_PASSCRED
 288 static int
 289 internal_function
 290 key_call_keyenvoy (u_long proc, xdrproc_t xdr_arg, char *arg,
 291                    xdrproc_t xdr_rslt, char *rslt)
 292 {
 293   XDR xdrargs;
 294   XDR xdrrslt;
 295   FILE *fargs;
 296   FILE *frslt;
 297   sigset_t oldmask, mask;
 298   union wait status;
 299   int pid;
 300   int success;
 301   uid_t ruid;
 302   uid_t euid;
 303   static const char MESSENGER[] = "/usr/etc/keyenvoy";
 304
 305   success = 1;
 306   sigemptyset (&mask);
 307   sigaddset (&mask, SIGCHLD);
 308   __sigprocmask (SIG_BLOCK, &mask, &oldmask);
 309
 310   /*
 311    * We are going to exec a set-uid program which makes our effective uid
 312    * zero, and authenticates us with our real uid. We need to make the
 313    * effective uid be the real uid for the setuid program, and
 314    * the real uid be the effective uid so that we can change things back.
 315    */
 316   euid = __geteuid ();
 317   ruid = __getuid ();
 318   __setreuid (euid, ruid);
 319   pid = _openchild (MESSENGER, &fargs, &frslt);
 320   __setreuid (ruid, euid);
 321   if (pid < 0)
 322     {
 323       debug ("open_streams");
 324       __sigprocmask (SIG_SETMASK, &oldmask, NULL);
 325       return (0);
 326     }
 327   xdrstdio_create (&xdrargs, fargs, XDR_ENCODE);
 328   xdrstdio_create (&xdrrslt, frslt, XDR_DECODE);
 329
 330   if (!INTUSE(xdr_u_long) (&xdrargs, &proc) || !(*xdr_arg) (&xdrargs, arg))
 331     {
 332       debug ("xdr args");
 333       success = 0;
 334     }
 335   fclose (fargs);
 336
 337   if (success && !(*xdr_rslt) (&xdrrslt, rslt))
 338     {
 339       debug ("xdr rslt");
 340       success = 0;
 341     }
 342   fclose(frslt);
 343
 344  wait_again:
 345   if (__wait4 (pid, &status, 0, NULL) < 0)
 346     {
 347       if (errno == EINTR)
 348         goto wait_again;
 349       debug ("wait4");
 350       if (errno == ECHILD || errno == ESRCH)
 351         perror ("wait");
 352       else
 353         success = 0;
 354     }
 355   else
 356     if (status.w_retcode)
 357       {
 358         debug ("wait4 1");
 359         success = 0;
 360       }
 361   __sigprocmask (SIG_SETMASK, &oldmask, NULL);
 362
 363   return success;
 364 }
 365 #endif
 366
 367 struct  key_call_private {
 368   CLIENT  *client;        /* Client handle */
 369   pid_t   pid;            /* process-id at moment of creation */
 370   uid_t   uid;            /* user-id at last authorization */
 371 };
 372 #ifdef _RPC_THREAD_SAFE_
 373 #define key_call_private_main ((struct  key_call_private *)RPC_THREAD_VARIABLE(key_call_private_s))
 374 #else
 375 static struct key_call_private *key_call_private_main;
 376 #endif
 377 __libc_lock_define_initialized (static, keycall_lock)
 378
 379 /*
 380  * Keep the handle cached.  This call may be made quite often.
 381  */
 382 static CLIENT *
 383 getkeyserv_handle (int vers)
 384 {
 385   struct key_call_private *kcp = key_call_private_main;
 386   struct timeval wait_time;
 387   int fd;
 388   struct sockaddr_un name;
 389   int namelen = sizeof(struct sockaddr_un);
 390
 391 #define TOTAL_TIMEOUT   30      /* total timeout talking to keyserver */
 392 #define TOTAL_TRIES     5       /* Number of tries */
 393
 394   if (kcp == (struct key_call_private *)NULL)
 395     {
 396       kcp = (struct key_call_private *)malloc (sizeof (*kcp));
 397       if (kcp == (struct key_call_private *)NULL)
 398         return (CLIENT *) NULL;
 399
 400       key_call_private_main = kcp;
 401       kcp->client = NULL;
 402     }
 403
 404   /* if pid has changed, destroy client and rebuild */
 405   if (kcp->client != NULL && kcp->pid != __getpid ())
 406     {
 407       clnt_destroy (kcp->client);
 408       kcp->client = NULL;
 409     }
 410
 411   if (kcp->client != NULL)
 412     {
 413       /* if other side closed socket, build handle again */
 414       clnt_control (kcp->client, CLGET_FD, (char *)&fd);
 415       if (__getpeername (fd,(struct sockaddr *)&name,&namelen) == -1)
 416         {
 417           auth_destroy (kcp->client->cl_auth);
 418           clnt_destroy (kcp->client);
 419           kcp->client = NULL;
 420         }
 421     }
 422
 423   if (kcp->client != NULL)
 424     {
 425       /* if uid has changed, build client handle again */
 426       if (kcp->uid != __geteuid ())
 427         {
 428         kcp->uid = __geteuid ();
 429         auth_destroy (kcp->client->cl_auth);
 430         kcp->client->cl_auth =
 431           INTUSE(authunix_create) ((char *)"", kcp->uid, 0, 0, NULL);
 432         if (kcp->client->cl_auth == NULL)
 433           {
 434             clnt_destroy (kcp->client);
 435             kcp->client = NULL;
 436             return ((CLIENT *) NULL);
 437           }
 438         }
 439       /* Change the version number to the new one */
 440       clnt_control (kcp->client, CLSET_VERS, (void *)&vers);
 441       return kcp->client;
 442     }
 443
 444   if ((kcp->client == (CLIENT *) NULL))
 445     /* Use the AF_UNIX transport */
 446     kcp->client = INTUSE(clnt_create) ("/var/run/keyservsock", KEY_PROG, vers,
 447                                        "unix");
 448
 449   if (kcp->client == (CLIENT *) NULL)
 450     return (CLIENT *) NULL;
 451
 452   kcp->uid = __geteuid ();
 453   kcp->pid = __getpid ();
 454   kcp->client->cl_auth = INTUSE(authunix_create) ((char *)"", kcp->uid, 0, 0,
 455                                                   NULL);
 456   if (kcp->client->cl_auth == NULL)
 457     {
 458       clnt_destroy (kcp->client);
 459       kcp->client = NULL;
 460       return (CLIENT *) NULL;
 461     }
 462
 463   wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
 464   wait_time.tv_usec = 0;
 465   clnt_control (kcp->client, CLSET_RETRY_TIMEOUT,
 466                 (char *)&wait_time);
 467   if (clnt_control (kcp->client, CLGET_FD, (char *)&fd))
 468     __fcntl (fd, F_SETFD, 1);  /* make it "close on exec" */
 469
 470   return kcp->client;
 471 }
 472
 473 /* returns  0 on failure, 1 on success */
 474 static int
 475 internal_function
 476 key_call_socket (u_long proc, xdrproc_t xdr_arg, char *arg,
 477                xdrproc_t xdr_rslt, char *rslt)
 478 {
 479   CLIENT *clnt;
 480   struct timeval wait_time;
 481   int result = 0;
 482
 483   __libc_lock_lock (keycall_lock);
 484   if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
 485       (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
 486       (proc == KEY_GET_CONV))
 487     clnt = getkeyserv_handle(2); /* talk to version 2 */
 488   else
 489     clnt = getkeyserv_handle(1); /* talk to version 1 */
 490
 491   if (clnt != NULL)
 492     {
 493       wait_time.tv_sec = TOTAL_TIMEOUT;
 494       wait_time.tv_usec = 0;
 495
 496       if (clnt_call (clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
 497                      wait_time) == RPC_SUCCESS)
 498         result = 1;
 499     }
 500
 501   __libc_lock_unlock (keycall_lock);
 502
 503   return result;
 504 }
 505
 506 #ifdef HAVE_DOORS
 507 /* returns 0 on failure, 1 on success */
 508 static int
 509 internal_function
 510 key_call_door (u_long proc, xdrproc_t xdr_arg, char *arg,
 511                xdrproc_t xdr_rslt, char *rslt)
 512 {
 513   XDR xdrs;
 514   int fd, ret;
 515   door_arg_t args;
 516   char *data_ptr;
 517   u_long data_len = 0;
 518   char res[255];
 519
 520   if ((fd = open("/var/run/keyservdoor", O_RDONLY)) < 0)
 521     return 0;
 522   res[0] = 0;
 523
 524   data_len = xdr_sizeof (xdr_arg, arg);
 525   data_ptr = calloc (1, data_len + 2 * sizeof (u_long));
 526   if (data_ptr == NULL)
 527     return 0;
 528
 529   INTUSE(xdrmem_create) (&xdrs, &data_ptr[2 * sizeof (u_long)], data_len,
 530                          XDR_ENCODE);
 531   if (!xdr_arg (&xdrs, arg))
 532     {
 533       xdr_destroy (&xdrs);
 534       free (data_ptr);
 535       return 0;
 536     }
 537   xdr_destroy (&xdrs);
 538
 539   memcpy (data_ptr, &proc, sizeof (u_long));
 540   memcpy (&data_ptr[sizeof (proc)], &data_len, sizeof (u_long));
 541
 542   args.data_ptr = data_ptr;
 543   args.data_size = data_len + 2 * sizeof (u_long);
 544   args.desc_ptr = NULL;
 545   args.desc_num = 0;
 546   args.rbuf = res;
 547   args.rsize = sizeof (res);
 548
 549   ret = __door_call (fd, &args);
 550   free (data_ptr);
 551   close (fd);
 552
 553   if (ret < 0)
 554     return 0;
 555
 556   memcpy (&data_len, args.data_ptr, sizeof (u_long));
 557   if (data_len != 0)
 558     return 0;
 559
 560   memcpy (&data_len, &args.data_ptr[sizeof (u_long)], sizeof (u_long));
 561   INTUSE(xdrmem_create) (&xdrs, &args.data_ptr[2 * sizeof (u_long)],
 562                          data_len, XDR_DECODE);
 563   if (!xdr_rslt (&xdrs, rslt))
 564     {
 565       xdr_destroy (&xdrs);
 566       return 0;
 567     }
 568   xdr_destroy (&xdrs);
 569
 570   return 1;
 571 }
 572 #endif
 573
 574 /* returns 0 on failure, 1 on success */
 575 static int
 576 internal_function
 577 key_call (u_long proc, xdrproc_t xdr_arg, char *arg,
 578           xdrproc_t xdr_rslt, char *rslt)
 579 {
 580 #ifndef SO_PASSCRED
 581   static int use_keyenvoy;
 582 #endif
 583 #ifdef HAVE_DOORS
 584   static int not_use_doors;
 585 #endif
 586
 587   if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL)
 588     {
 589       cryptkeyres *res;
 590       res = (*__key_encryptsession_pk_LOCAL) (__geteuid (), arg);
 591       *(cryptkeyres *) rslt = *res;
 592       return 1;
 593     }
 594   else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL)
 595     {
 596       cryptkeyres *res;
 597       res = (*__key_decryptsession_pk_LOCAL) (__geteuid (), arg);
 598       *(cryptkeyres *) rslt = *res;
 599       return 1;
 600     }
 601   else if (proc == KEY_GEN && __key_gendes_LOCAL)
 602     {
 603       des_block *res;
 604       res = (*__key_gendes_LOCAL) (__geteuid (), 0);
 605       *(des_block *) rslt = *res;
 606       return 1;
 607     }
 608
 609 #ifdef HAVE_DOORS
 610   if (!not_use_doors)
 611     {
 612       if (key_call_door (proc, xdr_arg, arg, xdr_rslt, rslt))
 613         return 1;
 614       not_use_doors = 1;
 615     }
 616 #endif
 617
 618 #ifdef SO_PASSCRED
 619   return key_call_socket (proc, xdr_arg, arg, xdr_rslt, rslt);
 620 #else
 621   if (!use_keyenvoy)
 622     {
 623       if (key_call_socket (proc, xdr_arg, arg, xdr_rslt, rslt))
 624         return 1;
 625       use_keyenvoy = 1;
 626     }
 627   return key_call_keyenvoy (proc, xdr_arg, arg, xdr_rslt, rslt);
 628 #endif
 629 }
 630
 631 #ifdef _RPC_THREAD_SAFE_
 632 void
 633 __rpc_thread_key_cleanup (void)
 634 {
 635         struct key_call_private *kcp = RPC_THREAD_VARIABLE(key_call_private_s);
 636
 637         if (kcp) {
 638                 if (kcp->client)
 639                         clnt_destroy(kcp->client);
 640                 free (kcp);
 641         }
 642 }
 643 #endif /* _RPC_THREAD_SAFE_ */