sunrpc/key_call.c

   1 /*
   2  * Copyright (c) 1988 by Sun Microsystems, Inc.
   3  */
   4 /*
   5  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   6  * unrestricted use provided that this legend is included on all tape
   7  * media and as a part of the software program in whole or part.  Users
   8  * may copy or modify Sun RPC without charge, but are not authorized
   9  * to license or distribute it to anyone else except as part of a product or
  10  * program developed by the user.
  11  *
  12  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  13  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  14  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  15  *
  16  * Sun RPC is provided with no support and without any obligation on the
  17  * part of Sun Microsystems, Inc. to assist in its use, correction,
  18  * modification or enhancement.
  19  *
  20  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  21  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  22  * OR ANY PART THEREOF.
  23  *
  24  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  25  * or profits or other special, indirect and consequential damages, even if
  26  * Sun has been advised of the possibility of such damages.
  27  *
  28  * Sun Microsystems, Inc.
  29  * 2550 Garcia Avenue
  30  * Mountain View, California  94043
  31  */
  32
  33 /*
  34  * The original source is from the RPCSRC 4.0 package from Sun Microsystems.
  35  * The Interface to keyserver protocoll 2, RPC over AF_UNIX und Linux/doors
  36  * was added by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>
  37  */
  38
  39 #include <stdio.h>
  40 #include <errno.h>
  41 #include <fcntl.h>
  42 #include <signal.h>
  43 #include <unistd.h>
  44 #include <string.h>
  45 #include <rpc/rpc.h>
  46 #include <rpc/auth.h>
  47 #include <sys/wait.h>
  48 #include <sys/param.h>
  49 #include <sys/socket.h>
  50 #include <rpc/key_prot.h>
  51 #include <bits/libc-lock.h>
  52
  53 #ifdef HAVE_DOORS
  54 # include "door/door.h"
  55 #endif
  56
  57 #define KEY_TIMEOUT     5       /* per-try timeout in seconds */
  58 #define KEY_NRETRY      12      /* number of retries */
  59
  60 #define debug(msg)              /* turn off debugging */
  61
  62 extern int _openchild (char *command, FILE **fto, FILE **ffrom);
  63
  64
  65 static int key_call (u_long, xdrproc_t xdr_arg, char *,
  66                      xdrproc_t xdr_rslt, char *) internal_function;
  67
  68 static struct timeval trytimeout = {KEY_TIMEOUT, 0};
  69 static struct timeval tottimeout = {KEY_TIMEOUT *KEY_NRETRY, 0};
  70
  71 int
  72 key_setsecret (char *secretkey)
  73 {
  74   keystatus status;
  75
  76   if (!key_call ((u_long) KEY_SET, (xdrproc_t) xdr_keybuf, secretkey,
  77                  (xdrproc_t) xdr_keystatus, (char *) &status))
  78     return -1;
  79   if (status != KEY_SUCCESS)
  80     {
  81       debug ("set status is nonzero");
  82       return -1;
  83     }
  84   return 0;
  85 }
  86
  87 /* key_secretkey_is_set() returns 1 if the keyserver has a secret key
  88  * stored for the caller's effective uid; it returns 0 otherwise
  89  *
  90  * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
  91  * be using it, because it allows them to get the user's secret key.
  92  */
  93 int
  94 key_secretkey_is_set (void)
  95 {
  96   struct key_netstres kres;
  97
  98   memset (&kres, 0, sizeof (kres));
  99   if (key_call ((u_long) KEY_NET_GET, (xdrproc_t) xdr_void, (char *) NULL,
 100                 (xdrproc_t) xdr_key_netstres, (char *) &kres) &&
 101       (kres.status == KEY_SUCCESS) &&
 102       (kres.key_netstres_u.knet.st_priv_key[0] != 0))
 103     {
 104       /* avoid leaving secret key in memory */
 105       memset (kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
 106       return 1;
 107     }
 108   return 0;
 109 }
 110
 111 int
 112 key_encryptsession (char *remotename, des_block *deskey)
 113 {
 114   cryptkeyarg arg;
 115   cryptkeyres res;
 116
 117   arg.remotename = remotename;
 118   arg.deskey = *deskey;
 119   if (!key_call ((u_long) KEY_ENCRYPT, (xdrproc_t) xdr_cryptkeyarg,
 120                  (char *) &arg, (xdrproc_t) xdr_cryptkeyres, (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) xdr_cryptkeyarg,
 141                  (char *) &arg, (xdrproc_t) xdr_cryptkeyres, (char *) &res))
 142     return -1;
 143   if (res.status != KEY_SUCCESS)
 144     {
 145       debug ("decrypt status is nonzero");
 146       return -1;
 147     }
 148   *deskey = res.cryptkeyres_u.deskey;
 149   return 0;
 150 }
 151
 152 int
 153 key_encryptsession_pk (char *remotename, netobj *remotekey,
 154                        des_block *deskey)
 155 {
 156   cryptkeyarg2 arg;
 157   cryptkeyres res;
 158
 159   arg.remotename = remotename;
 160   arg.remotekey = *remotekey;
 161   arg.deskey = *deskey;
 162   if (!key_call ((u_long) KEY_ENCRYPT_PK, (xdrproc_t) xdr_cryptkeyarg2,
 163                  (char *) &arg, (xdrproc_t) xdr_cryptkeyres, (char *) &res))
 164     return -1;
 165
 166   if (res.status != KEY_SUCCESS)
 167     {
 168       debug ("encrypt status is nonzero");
 169       return -1;
 170     }
 171   *deskey = res.cryptkeyres_u.deskey;
 172   return 0;
 173 }
 174
 175 int
 176 key_decryptsession_pk (char *remotename, netobj *remotekey,
 177                        des_block *deskey)
 178 {
 179   cryptkeyarg2 arg;
 180   cryptkeyres res;
 181
 182   arg.remotename = remotename;
 183   arg.remotekey = *remotekey;
 184   arg.deskey = *deskey;
 185   if (!key_call ((u_long) KEY_DECRYPT_PK, (xdrproc_t) xdr_cryptkeyarg2,
 186                  (char *) &arg, (xdrproc_t) xdr_cryptkeyres, (char *) &res))
 187     return -1;
 188
 189   if (res.status != KEY_SUCCESS)
 190     {
 191       debug ("decrypt status is nonzero");
 192       return -1;
 193     }
 194   *deskey = res.cryptkeyres_u.deskey;
 195   return 0;
 196 }
 197
 198 int
 199 key_gendes (des_block *key)
 200 {
 201   struct sockaddr_in sin;
 202   CLIENT *client;
 203   int socket;
 204   enum clnt_stat stat;
 205
 206   sin.sin_family = AF_INET;
 207   sin.sin_port = 0;
 208   sin.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
 209   __bzero (sin.sin_zero, sizeof (sin.sin_zero));
 210   socket = RPC_ANYSOCK;
 211   client = clntudp_bufcreate (&sin, (u_long) KEY_PROG, (u_long) KEY_VERS,
 212                               trytimeout, &socket, RPCSMALLMSGSIZE,
 213                               RPCSMALLMSGSIZE);
 214   if (client == NULL)
 215     return -1;
 216
 217   stat = clnt_call (client, KEY_GEN, (xdrproc_t) xdr_void, NULL,
 218                     (xdrproc_t) xdr_des_block, (caddr_t) key, tottimeout);
 219   clnt_destroy (client);
 220   __close (socket);
 221   if (stat != RPC_SUCCESS)
 222     return -1;
 223
 224   return 0;
 225 }
 226
 227 int
 228 key_setnet (struct key_netstarg *arg)
 229 {
 230   keystatus status;
 231
 232   if (!key_call ((u_long) KEY_NET_PUT, (xdrproc_t) xdr_key_netstarg,
 233                  (char *) arg,(xdrproc_t) xdr_keystatus, (char *) &status))
 234     return -1;
 235
 236   if (status != KEY_SUCCESS)
 237     {
 238       debug ("key_setnet status is nonzero");
 239       return -1;
 240     }
 241   return 1;
 242 }
 243
 244 int
 245 key_get_conv (char *pkey, des_block *deskey)
 246 {
 247   cryptkeyres res;
 248
 249   if (!key_call ((u_long) KEY_GET_CONV, (xdrproc_t) xdr_keybuf, pkey,
 250                  (xdrproc_t) xdr_cryptkeyres, (char *) &res))
 251     return -1;
 252
 253   if (res.status != KEY_SUCCESS)
 254     {
 255       debug ("get_conv status is nonzero");
 256       return -1;
 257     }
 258   *deskey = res.cryptkeyres_u.deskey;
 259   return 0;
 260 }
 261
 262 /*
 263  * Hack to allow the keyserver to use AUTH_DES (for authenticated
 264  * NIS+ calls, for example).  The only functions that get called
 265  * are key_encryptsession_pk, key_decryptsession_pk, and key_gendes.
 266  *
 267  * The approach is to have the keyserver fill in pointers to local
 268  * implementations of these functions, and to call those in key_call().
 269  */
 270
 271 cryptkeyres *(*__key_encryptsession_pk_LOCAL) (uid_t, char *) = 0;
 272 cryptkeyres *(*__key_decryptsession_pk_LOCAL) (uid_t, char *) = 0;
 273 des_block *(*__key_gendes_LOCAL) (uid_t, char *) = 0;
 274
 275 static int
 276 internal_function
 277 key_call_keyenvoy (u_long proc, xdrproc_t xdr_arg, char *arg,
 278                    xdrproc_t xdr_rslt, char *rslt)
 279 {
 280   XDR xdrargs;
 281   XDR xdrrslt;
 282   FILE *fargs;
 283   FILE *frslt;
 284   sigset_t oldmask, mask;
 285   union wait status;
 286   int pid;
 287   int success;
 288   uid_t ruid;
 289   uid_t euid;
 290   static char MESSENGER[] = "/usr/etc/keyenvoy";
 291
 292   success = 1;
 293   sigemptyset (&mask);
 294   sigaddset (&mask, SIGCHLD);
 295   __sigprocmask (SIG_BLOCK, &mask, &oldmask);
 296
 297   /*
 298    * We are going to exec a set-uid program which makes our effective uid
 299    * zero, and authenticates us with our real uid. We need to make the
 300    * effective uid be the real uid for the setuid program, and
 301    * the real uid be the effective uid so that we can change things back.
 302    */
 303   euid = __geteuid ();
 304   ruid = __getuid ();
 305   __setreuid (euid, ruid);
 306   pid = _openchild (MESSENGER, &fargs, &frslt);
 307   __setreuid (ruid, euid);
 308   if (pid < 0)
 309     {
 310       debug ("open_streams");
 311       __sigprocmask (SIG_SETMASK, &oldmask, NULL);
 312       return (0);
 313     }
 314   xdrstdio_create (&xdrargs, fargs, XDR_ENCODE);
 315   xdrstdio_create (&xdrrslt, frslt, XDR_DECODE);
 316
 317   if (!xdr_u_long (&xdrargs, &proc) || !(*xdr_arg) (&xdrargs, arg))
 318     {
 319       debug ("xdr args");
 320       success = 0;
 321     }
 322   fclose (fargs);
 323
 324   if (success && !(*xdr_rslt) (&xdrrslt, rslt))
 325     {
 326       debug ("xdr rslt");
 327       success = 0;
 328     }
 329   fclose(frslt);
 330
 331  wait_again:
 332   if (__wait4 (pid, &status, 0, NULL) < 0)
 333     {
 334       if (errno == EINTR)
 335         goto wait_again;
 336       debug ("wait4");
 337       if (errno == ECHILD || errno == ESRCH)
 338         perror ("wait");
 339       else
 340         success = 0;
 341     }
 342   else
 343     if (status.w_retcode)
 344       {
 345         debug ("wait4 1");
 346         success = 0;
 347       }
 348   __sigprocmask (SIG_SETMASK, &oldmask, NULL);
 349
 350   return success;
 351 }
 352
 353 struct  key_call_private {
 354   CLIENT  *client;        /* Client handle */
 355   pid_t   pid;            /* process-id at moment of creation */
 356   uid_t   uid;            /* user-id at last authorization */
 357 };
 358 static struct key_call_private *key_call_private_main = NULL;
 359 __libc_lock_define_initialized (static, keycall_lock)
 360
 361 /*
 362  * Keep the handle cached.  This call may be made quite often.
 363  */
 364 static CLIENT *
 365 getkeyserv_handle (int vers)
 366 {
 367   struct key_call_private *kcp = key_call_private_main;
 368   struct timeval wait_time;
 369   int fd;
 370   struct sockaddr_un name;
 371   int namelen = sizeof(struct sockaddr_un);
 372
 373 #define TOTAL_TIMEOUT   30      /* total timeout talking to keyserver */
 374 #define TOTAL_TRIES     5       /* Number of tries */
 375
 376   if (kcp == (struct key_call_private *)NULL)
 377     {
 378       kcp = (struct key_call_private *)malloc (sizeof (*kcp));
 379       if (kcp == (struct key_call_private *)NULL)
 380         return (CLIENT *) NULL;
 381
 382       key_call_private_main = kcp;
 383       kcp->client = NULL;
 384     }
 385
 386   /* if pid has changed, destroy client and rebuild */
 387   if (kcp->client != NULL && kcp->pid != __getpid ())
 388     {
 389       clnt_destroy (kcp->client);
 390       kcp->client = NULL;
 391     }
 392
 393   if (kcp->client != NULL)
 394     {
 395       /* if other side closed socket, build handle again */
 396       clnt_control (kcp->client, CLGET_FD, (char *)&fd);
 397       if (getpeername (fd,(struct sockaddr *)&name,&namelen) == -1)
 398         {
 399           auth_destroy (kcp->client->cl_auth);
 400           clnt_destroy (kcp->client);
 401           kcp->client = NULL;
 402         }
 403     }
 404
 405   if (kcp->client != NULL)
 406     {
 407       /* if uid has changed, build client handle again */
 408       if (kcp->uid != __geteuid ())
 409         {
 410         kcp->uid = __geteuid ();
 411         auth_destroy (kcp->client->cl_auth);
 412         kcp->client->cl_auth =
 413           authunix_create ((char *)"", kcp->uid, 0, 0, NULL);
 414         if (kcp->client->cl_auth == NULL)
 415           {
 416             clnt_destroy (kcp->client);
 417             kcp->client = NULL;
 418             return ((CLIENT *) NULL);
 419           }
 420         }
 421       /* Change the version number to the new one */
 422       clnt_control (kcp->client, CLSET_VERS, (void *)&vers);
 423       return kcp->client;
 424     }
 425
 426   if ((kcp->client == (CLIENT *) NULL))
 427     /* Use the AF_UNIX transport */
 428     kcp->client = clnt_create ("/var/run/keyservsock", KEY_PROG, vers, "unix");
 429
 430   if (kcp->client == (CLIENT *) NULL)
 431     return (CLIENT *) NULL;
 432
 433   kcp->uid = __geteuid ();
 434   kcp->pid = __getpid ();
 435   kcp->client->cl_auth = authunix_create ((char *)"", kcp->uid, 0, 0, NULL);
 436   if (kcp->client->cl_auth == NULL)
 437     {
 438       clnt_destroy (kcp->client);
 439       kcp->client = NULL;
 440       return (CLIENT *) NULL;
 441     }
 442
 443   wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
 444   wait_time.tv_usec = 0;
 445   clnt_control (kcp->client, CLSET_RETRY_TIMEOUT,
 446                 (char *)&wait_time);
 447   if (clnt_control (kcp->client, CLGET_FD, (char *)&fd))
 448     fcntl (fd, F_SETFD, 1);  /* make it "close on exec" */
 449
 450   return kcp->client;
 451 }
 452
 453 /* returns  0 on failure, 1 on success */
 454 static int
 455 internal_function
 456 key_call_socket (u_long proc, xdrproc_t xdr_arg, char *arg,
 457                xdrproc_t xdr_rslt, char *rslt)
 458 {
 459   CLIENT *clnt;
 460   struct timeval wait_time;
 461   int result = 0;
 462
 463   __libc_lock_lock (keycall_lock);
 464   if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
 465       (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
 466       (proc == KEY_GET_CONV))
 467     clnt = getkeyserv_handle(2); /* talk to version 2 */
 468   else
 469     clnt = getkeyserv_handle(1); /* talk to version 1 */
 470
 471   if (clnt != NULL)
 472     {
 473       wait_time.tv_sec = TOTAL_TIMEOUT;
 474       wait_time.tv_usec = 0;
 475
 476       if (clnt_call (clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
 477                      wait_time) == RPC_SUCCESS)
 478         result = 1;
 479     }
 480
 481   __libc_lock_unlock (keycall_lock);
 482
 483   return result;
 484 }
 485
 486 #ifdef HAVE_DOORS
 487 /* returns 0 on failure, 1 on success */
 488 static int
 489 internal_function
 490 key_call_door (u_long proc, xdrproc_t xdr_arg, char *arg,
 491                xdrproc_t xdr_rslt, char *rslt)
 492 {
 493   XDR xdrs;
 494   int fd;
 495   door_arg_t args;
 496   char *data_ptr;
 497   u_long data_len = 0;
 498   char res[255];
 499
 500   if ((fd = open("/var/run/keyservdoor", O_RDONLY)) < 0)
 501     return 0;
 502   res[0] = 0;
 503
 504   data_len = xdr_sizeof (xdr_arg, arg);
 505   data_ptr = calloc (1, data_len + 2 * sizeof (u_long));
 506   if (data_ptr == NULL)
 507     return 0;
 508
 509   xdrmem_create (&xdrs, &data_ptr[2 * sizeof (u_long)], data_len, XDR_ENCODE);
 510   if (!xdr_arg (&xdrs, arg))
 511     {
 512       xdr_destroy (&xdrs);
 513       free (data_ptr);
 514       return 0;
 515     }
 516   xdr_destroy (&xdrs);
 517
 518   memcpy (data_ptr, &proc, sizeof (u_long));
 519   memcpy (&data_ptr[sizeof (proc)], &data_len, sizeof (u_long));
 520
 521   args.data_ptr = data_ptr;
 522   args.data_size = data_len + 2 * sizeof (u_long);
 523   args.desc_ptr = NULL;
 524   args.desc_num = 0;
 525   args.rbuf = res;
 526   args.rsize = sizeof (res);
 527
 528   if (__door_call (fd, &args) < 0)
 529     return 0;
 530
 531   free (data_ptr);
 532   close (fd);
 533
 534   memcpy (&data_len, args.data_ptr, sizeof (u_long));
 535   if (data_len != 0)
 536     return 0;
 537
 538   memcpy (&data_len, &args.data_ptr[sizeof (u_long)], sizeof (u_long));
 539   xdrmem_create (&xdrs, &args.data_ptr[2 * sizeof (u_long)],
 540                  data_len, XDR_DECODE);
 541   if (!xdr_rslt (&xdrs, rslt))
 542     {
 543       xdr_destroy (&xdrs);
 544       return 0;
 545     }
 546   xdr_destroy (&xdrs);
 547
 548   return 1;
 549 }
 550 #endif
 551
 552 /* returns 0 on failure, 1 on success */
 553 static int
 554 internal_function
 555 key_call (u_long proc, xdrproc_t xdr_arg, char *arg,
 556           xdrproc_t xdr_rslt, char *rslt)
 557 {
 558   static int use_keyenvoy = 0;
 559 #ifdef HAVE_DOORS
 560   static int use_doors = 1;
 561 #endif
 562
 563   if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL)
 564     {
 565       cryptkeyres *res;
 566       res = (*__key_encryptsession_pk_LOCAL) (__geteuid (), arg);
 567       *(cryptkeyres *) rslt = *res;
 568       return 1;
 569     }
 570   else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL)
 571     {
 572       cryptkeyres *res;
 573       res = (*__key_decryptsession_pk_LOCAL) (__geteuid (), arg);
 574       *(cryptkeyres *) rslt = *res;
 575       return 1;
 576     }
 577   else if (proc == KEY_GEN && __key_gendes_LOCAL)
 578     {
 579       des_block *res;
 580       res = (*__key_gendes_LOCAL) (__geteuid (), 0);
 581       *(des_block *) rslt = *res;
 582       return 1;
 583     }
 584
 585 #ifdef HAVE_DOORS
 586   if (use_doors)
 587     {
 588       if (key_call_door (proc, xdr_arg, arg, xdr_rslt, rslt))
 589         return 1;
 590       use_doors = 0;
 591     }
 592 #endif
 593   if (!use_keyenvoy)
 594     {
 595       if (key_call_socket (proc, xdr_arg, arg, xdr_rslt, rslt))
 596         return 1;
 597       use_keyenvoy = 1;
 598     }
 599   return key_call_keyenvoy (proc, xdr_arg, arg, xdr_rslt, rslt);
 600 }