aboutsummaryrefslogtreecommitdiff
path: root/sunrpc/key_call.c
blob: 0219eaf5ad0ad777fffe91f75ab28c1f17e1d194 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
/*
 * Copyright (c) 1988 by Sun Microsystems, Inc.
 */
/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

/*
 * The original source is from the RPCSRC 4.0 package from Sun Microsystems.
 * The Interface to keyserver protocoll 2 was added by
 * Thorsten Kukuk <kukuk@vt.uni-paderborn.de>
 */

#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <string.h>
#include <rpc/rpc.h>
#include <rpc/auth.h>
#include <sys/wait.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <rpc/key_prot.h>
#include <bits/libc-lock.h>

#define KEY_TIMEOUT	5	/* per-try timeout in seconds */
#define KEY_NRETRY	12	/* number of retries */

#define debug(msg)		/* turn off debugging */

extern int _openchild (char *command, FILE **fto, FILE **ffrom);


static int key_call (u_long, xdrproc_t xdr_arg, char *,
		     xdrproc_t xdr_rslt, char *) internal_function;

static struct timeval trytimeout = {KEY_TIMEOUT, 0};
static struct timeval tottimeout = {KEY_TIMEOUT *KEY_NRETRY, 0};

int
key_setsecret (char *secretkey)
{
  keystatus status;

  if (!key_call ((u_long) KEY_SET, (xdrproc_t) xdr_keybuf, secretkey,
		 (xdrproc_t) xdr_keystatus, (char *) &status))
    return -1;
  if (status != KEY_SUCCESS)
    {
      debug ("set status is nonzero");
      return -1;
    }
  return 0;
}

/* key_secretkey_is_set() returns 1 if the keyserver has a secret key
 * stored for the caller's effective uid; it returns 0 otherwise
 *
 * N.B.:  The KEY_NET_GET key call is undocumented.  Applications shouldn't
 * be using it, because it allows them to get the user's secret key.
 */
int
key_secretkey_is_set (void)
{
  struct key_netstres kres;

  memset (&kres, 0, sizeof (kres));
  if (key_call ((u_long) KEY_NET_GET, (xdrproc_t) xdr_void, (char *) NULL,
		(xdrproc_t) xdr_key_netstres, (char *) &kres) &&
      (kres.status == KEY_SUCCESS) &&
      (kres.key_netstres_u.knet.st_priv_key[0] != 0))
    {
      /* avoid leaving secret key in memory */
      memset (kres.key_netstres_u.knet.st_priv_key, 0, HEXKEYBYTES);
      return 1;
    }
  return 0;
}

int
key_encryptsession (char *remotename, des_block *deskey)
{
  cryptkeyarg arg;
  cryptkeyres res;

  arg.remotename = remotename;
  arg.deskey = *deskey;
  if (!key_call ((u_long) KEY_ENCRYPT, (xdrproc_t) xdr_cryptkeyarg,
		 (char *) &arg, (xdrproc_t) xdr_cryptkeyres, (char *) &res))
    return -1;

  if (res.status != KEY_SUCCESS)
    {
      debug ("encrypt status is nonzero");
      return -1;
    }
  *deskey = res.cryptkeyres_u.deskey;
  return 0;
}

int
key_decryptsession (char *remotename, des_block *deskey)
{
  cryptkeyarg arg;
  cryptkeyres res;

  arg.remotename = remotename;
  arg.deskey = *deskey;
  if (!key_call ((u_long) KEY_DECRYPT, (xdrproc_t) xdr_cryptkeyarg,
		 (char *) &arg, (xdrproc_t) xdr_cryptkeyres, (char *) &res))
    return -1;
  if (res.status != KEY_SUCCESS)
    {
      debug ("decrypt status is nonzero");
      return -1;
    }
  *deskey = res.cryptkeyres_u.deskey;
  return 0;
}

int
key_encryptsession_pk (char *remotename, netobj *remotekey,
		       des_block *deskey)
{
  cryptkeyarg2 arg;
  cryptkeyres res;

  arg.remotename = remotename;
  arg.remotekey = *remotekey;
  arg.deskey = *deskey;
  if (!key_call ((u_long) KEY_ENCRYPT_PK, (xdrproc_t) xdr_cryptkeyarg2,
		 (char *) &arg, (xdrproc_t) xdr_cryptkeyres, (char *) &res))
    return -1;

  if (res.status != KEY_SUCCESS)
    {
      debug ("encrypt status is nonzero");
      return -1;
    }
  *deskey = res.cryptkeyres_u.deskey;
  return 0;
}

int
key_decryptsession_pk (char *remotename, netobj *remotekey,
		       des_block *deskey)
{
  cryptkeyarg2 arg;
  cryptkeyres res;

  arg.remotename = remotename;
  arg.remotekey = *remotekey;
  arg.deskey = *deskey;
  if (!key_call ((u_long) KEY_DECRYPT_PK, (xdrproc_t) xdr_cryptkeyarg2,
		 (char *) &arg, (xdrproc_t) xdr_cryptkeyres, (char *) &res))
    return -1;

  if (res.status != KEY_SUCCESS)
    {
      debug ("decrypt status is nonzero");
      return -1;
    }
  *deskey = res.cryptkeyres_u.deskey;
  return 0;
}

int
key_gendes (des_block *key)
{
  struct sockaddr_in sin;
  CLIENT *client;
  int socket;
  enum clnt_stat stat;

  sin.sin_family = AF_INET;
  sin.sin_port = 0;
  sin.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
  __bzero (sin.sin_zero, sizeof (sin.sin_zero));
  socket = RPC_ANYSOCK;
  client = clntudp_bufcreate (&sin, (u_long) KEY_PROG, (u_long) KEY_VERS,
			      trytimeout, &socket, RPCSMALLMSGSIZE,
			      RPCSMALLMSGSIZE);
  if (client == NULL)
    return -1;

  stat = clnt_call (client, KEY_GEN, (xdrproc_t) xdr_void, NULL,
		    (xdrproc_t) xdr_des_block, (caddr_t) key, tottimeout);
  clnt_destroy (client);
  __close (socket);
  if (stat != RPC_SUCCESS)
    return -1;

  return 0;
}

int
key_setnet (struct key_netstarg *arg)
{
  keystatus status;

  if (!key_call ((u_long) KEY_NET_PUT, (xdrproc_t) xdr_key_netstarg,
		 (char *) arg,(xdrproc_t) xdr_keystatus, (char *) &status))
    return -1;

  if (status != KEY_SUCCESS)
    {
      debug ("key_setnet status is nonzero");
      return -1;
    }
  return 1;
}

int
key_get_conv (char *pkey, des_block *deskey)
{
  cryptkeyres res;

  if (!key_call ((u_long) KEY_GET_CONV, (xdrproc_t) xdr_keybuf, pkey,
		 (xdrproc_t) xdr_cryptkeyres, (char *) &res))
    return -1;

  if (res.status != KEY_SUCCESS)
    {
      debug ("get_conv status is nonzero");
      return -1;
    }
  *deskey = res.cryptkeyres_u.deskey;
  return 0;
}

/*
 * Hack to allow the keyserver to use AUTH_DES (for authenticated
 * NIS+ calls, for example).  The only functions that get called
 * are key_encryptsession_pk, key_decryptsession_pk, and key_gendes.
 *
 * The approach is to have the keyserver fill in pointers to local
 * implementations of these functions, and to call those in key_call().
 */

cryptkeyres *(*__key_encryptsession_pk_LOCAL) (uid_t, char *) = 0;
cryptkeyres *(*__key_decryptsession_pk_LOCAL) (uid_t, char *) = 0;
des_block *(*__key_gendes_LOCAL) (uid_t, char *) = 0;

static int
internal_function
key_call_keyenvoy (u_long proc, xdrproc_t xdr_arg, char *arg,
		   xdrproc_t xdr_rslt, char *rslt)
{
  XDR xdrargs;
  XDR xdrrslt;
  FILE *fargs;
  FILE *frslt;
  sigset_t oldmask, mask;
  union wait status;
  int pid;
  int success;
  uid_t ruid;
  uid_t euid;
  static char MESSENGER[] = "/usr/etc/keyenvoy";

  success = 1;
  sigemptyset (&mask);
  sigaddset (&mask, SIGCHLD);
  __sigprocmask (SIG_BLOCK, &mask, &oldmask);

  /*
   * We are going to exec a set-uid program which makes our effective uid
   * zero, and authenticates us with our real uid. We need to make the
   * effective uid be the real uid for the setuid program, and
   * the real uid be the effective uid so that we can change things back.
   */
  euid = __geteuid ();
  ruid = __getuid ();
  __setreuid (euid, ruid);
  pid = _openchild (MESSENGER, &fargs, &frslt);
  __setreuid (ruid, euid);
  if (pid < 0)
    {
      debug ("open_streams");
      __sigprocmask (SIG_SETMASK, &oldmask, NULL);
      return (0);
    }
  xdrstdio_create (&xdrargs, fargs, XDR_ENCODE);
  xdrstdio_create (&xdrrslt, frslt, XDR_DECODE);

  if (!xdr_u_long (&xdrargs, &proc) || !(*xdr_arg) (&xdrargs, arg))
    {
      debug ("xdr args");
      success = 0;
    }
  fclose (fargs);

  if (success && !(*xdr_rslt) (&xdrrslt, rslt))
    {
      debug ("xdr rslt");
      success = 0;
    }
  fclose(frslt);

 wait_again:
  if (__wait4 (pid, &status, 0, NULL) < 0)
    {
      if (errno == EINTR)
	goto wait_again;
      debug ("wait4");
      if (errno == ECHILD || errno == ESRCH)
	perror ("wait");
      else
	success = 0;
    }
  else
    if (status.w_retcode)
      {
	debug ("wait4 1");
	success = 0;
      }
  __sigprocmask (SIG_SETMASK, &oldmask, NULL);

  return success;
}

struct  key_call_private {
  CLIENT  *client;        /* Client handle */
  pid_t   pid;            /* process-id at moment of creation */
  uid_t   uid;            /* user-id at last authorization */
};
static struct key_call_private *key_call_private_main = NULL;
__libc_lock_define_initialized (static, keycall_lock)

/*
 * Keep the handle cached.  This call may be made quite often.
 */
static CLIENT *
getkeyserv_handle (int vers)
{
  struct key_call_private *kcp = key_call_private_main;
  struct timeval wait_time;
  int fd;
  struct sockaddr_un name;
  int namelen = sizeof(struct sockaddr_un);

#define TOTAL_TIMEOUT   30      /* total timeout talking to keyserver */
#define TOTAL_TRIES     5       /* Number of tries */

  if (kcp == (struct key_call_private *)NULL)
    {
      kcp = (struct key_call_private *)malloc (sizeof (*kcp));
      if (kcp == (struct key_call_private *)NULL)
	return (CLIENT *) NULL;

      key_call_private_main = kcp;
      kcp->client = NULL;
    }

  /* if pid has changed, destroy client and rebuild */
  if (kcp->client != NULL && kcp->pid != __getpid ())
    {
      clnt_destroy (kcp->client);
      kcp->client = NULL;
    }

  if (kcp->client != NULL)
    {
      /* if other side closed socket, build handle again */
      clnt_control (kcp->client, CLGET_FD, (char *)&fd);
      if (getpeername (fd,(struct sockaddr *)&name,&namelen) == -1)
	{
	  auth_destroy (kcp->client->cl_auth);
	  clnt_destroy (kcp->client);
	  kcp->client = NULL;
	}
    }

  if (kcp->client != NULL)
    {
      /* if uid has changed, build client handle again */
      if (kcp->uid != __geteuid ())
	{
        kcp->uid = __geteuid ();
        auth_destroy (kcp->client->cl_auth);
        kcp->client->cl_auth =
          authunix_create ((char *)"", kcp->uid, 0, 0, NULL);
        if (kcp->client->cl_auth == NULL)
          {
            clnt_destroy (kcp->client);
            kcp->client = NULL;
            return ((CLIENT *) NULL);
          }
	}
      /* Change the version number to the new one */
      clnt_control (kcp->client, CLSET_VERS, (void *)&vers);
      return kcp->client;
    }

  if ((kcp->client == (CLIENT *) NULL))
    /* Use the AF_UNIX transport */
    kcp->client = clnt_create ("/var/run/keyservsock", KEY_PROG, vers, "unix");

  if (kcp->client == (CLIENT *) NULL)
    return (CLIENT *) NULL;

  kcp->uid = __geteuid ();
  kcp->pid = __getpid ();
  kcp->client->cl_auth = authunix_create ((char *)"", kcp->uid, 0, 0, NULL);
  if (kcp->client->cl_auth == NULL)
    {
      clnt_destroy (kcp->client);
      kcp->client = NULL;
      return (CLIENT *) NULL;
    }

  wait_time.tv_sec = TOTAL_TIMEOUT/TOTAL_TRIES;
  wait_time.tv_usec = 0;
  clnt_control (kcp->client, CLSET_RETRY_TIMEOUT,
		(char *)&wait_time);
  if (clnt_control (kcp->client, CLGET_FD, (char *)&fd))
    fcntl (fd, F_SETFD, 1);  /* make it "close on exec" */

  return kcp->client;
}

/* returns  0 on failure, 1 on success */
static int
internal_function
key_call_socket (u_long proc, xdrproc_t xdr_arg, char *arg,
               xdrproc_t xdr_rslt, char *rslt)
{
  CLIENT *clnt;
  struct timeval wait_time;
  int result = 0;

  __libc_lock_lock (keycall_lock);
  if ((proc == KEY_ENCRYPT_PK) || (proc == KEY_DECRYPT_PK) ||
      (proc == KEY_NET_GET) || (proc == KEY_NET_PUT) ||
      (proc == KEY_GET_CONV))
    clnt = getkeyserv_handle(2); /* talk to version 2 */
  else
    clnt = getkeyserv_handle(1); /* talk to version 1 */

  if (clnt != NULL)
    {
      wait_time.tv_sec = TOTAL_TIMEOUT;
      wait_time.tv_usec = 0;

      if (clnt_call (clnt, proc, xdr_arg, arg, xdr_rslt, rslt,
		     wait_time) == RPC_SUCCESS)
	result = 1;
    }

  __libc_lock_unlock (keycall_lock);

  return result;
}

/* returns  0 on failure, 1 on success */
static int
internal_function
key_call (u_long proc, xdrproc_t xdr_arg, char *arg,
	  xdrproc_t xdr_rslt, char *rslt)
{
  static int use_keyenvoy = 0;

  if (proc == KEY_ENCRYPT_PK && __key_encryptsession_pk_LOCAL)
    {
      cryptkeyres *res;
      res = (*__key_encryptsession_pk_LOCAL) (__geteuid (), arg);
      *(cryptkeyres *) rslt = *res;
      return 1;
    }
  else if (proc == KEY_DECRYPT_PK && __key_decryptsession_pk_LOCAL)
    {
      cryptkeyres *res;
      res = (*__key_decryptsession_pk_LOCAL) (__geteuid (), arg);
      *(cryptkeyres *) rslt = *res;
      return 1;
    }
  else if (proc == KEY_GEN && __key_gendes_LOCAL)
    {
      des_block *res;
      res = (*__key_gendes_LOCAL) (__geteuid (), 0);
      *(des_block *) rslt = *res;
      return 1;
    }

  if (!use_keyenvoy)
    {
      if (key_call_socket (proc, xdr_arg, arg, xdr_rslt, rslt))
	return 1;
      use_keyenvoy = 1;
    }
  return key_call_keyenvoy (proc, xdr_arg, arg, xdr_rslt, rslt);
}