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