aboutsummaryrefslogtreecommitdiff
path: root/lib/ssluse.c
blob: a3cf492b968404c8e413186dc1930587d31cf423 (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
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
/*****************************************************************************
 *                                  _   _ ____  _     
 *  Project                     ___| | | |  _ \| |    
 *                             / __| | | | |_) | |    
 *                            | (__| |_| |  _ <| |___ 
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 2000, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * In order to be useful for every potential user, curl and libcurl are
 * dual-licensed under the MPL and the MIT/X-derivate licenses.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the MPL or the MIT/X-derivate
 * licenses. You may pick one of these licenses.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * $Id$
 *****************************************************************************/

/*
 * The original SSL code was written by
 * Linas Vepstas <linas@linas.org> and Sampo Kellomaki <sampo@iki.fi>
 */

#include "setup.h"
#include <string.h>
#include <stdlib.h>

#include "urldata.h"
#include "sendf.h"
#include "formdata.h" /* for the boundary function */

#ifdef USE_SSLEAY
#include <openssl/rand.h>

/* The last #include file should be: */
#ifdef MALLOCDEBUG
#include "memdebug.h"
#endif

#if OPENSSL_VERSION_NUMBER >= 0x00904100L
#define HAVE_USERDATA_IN_PWD_CALLBACK 1
#else
#undef HAVE_USERDATA_IN_PWD_CALLBACK
#endif

#ifndef HAVE_USERDATA_IN_PWD_CALLBACK
static char global_passwd[64];
#endif

static int passwd_callback(char *buf, int num, int verify
#if HAVE_USERDATA_IN_PWD_CALLBACK
                           /* This was introduced in 0.9.4, we can set this
                              using SSL_CTX_set_default_passwd_cb_userdata()
                              */
                           , void *global_passwd
#endif
                           )
{
  if(verify)
    fprintf(stderr, "%s\n", buf);
  else {
    if(num > (int)strlen((char *)global_passwd)) {
      strcpy(buf, global_passwd);
      return strlen(buf);
    }
  }  
  return 0;
}

static
bool seed_enough(struct connectdata *conn, /* unused for now */
                 int nread)
{
  conn = NULL; /* to prevent compiler warnings */
#ifdef HAVE_RAND_STATUS
  nread = 0; /* to prevent compiler warnings */

  /* only available in OpenSSL 0.9.5a and later */
  if(RAND_status())
    return TRUE;
#else
  if(nread > 500)
    /* this is a very silly decision to make */
    return TRUE;
#endif
  return FALSE; /* not enough */
}

static
int random_the_seed(struct connectdata *conn)
{
  char *buf = conn->data->state.buffer; /* point to the big buffer */
  int nread=0;
  struct SessionHandle *data=conn->data;

  /* Q: should we add support for a random file name as a libcurl option?
     A: Yes, it is here */

#ifndef RANDOM_FILE
  /* if RANDOM_FILE isn't defined, we only perform this if an option tells
     us to! */
  if(data->set.ssl.random_file)
#define RANDOM_FILE "" /* doesn't matter won't be used */
#endif
  {
    /* let the option override the define */
    nread += RAND_load_file((data->set.ssl.random_file?
                             data->set.ssl.random_file:RANDOM_FILE),
                            16384);
    if(seed_enough(conn, nread))
      return nread;
  }

#if defined(HAVE_RAND_EGD)
  /* only available in OpenSSL 0.9.5 and later */
  /* EGD_SOCKET is set at configure time or not at all */
#ifndef EGD_SOCKET
  /* If we don't have the define set, we only do this if the egd-option
     is set */
  if(data->set.ssl.egdsocket)
#define EGD_SOCKET "" /* doesn't matter won't be used */
#endif
  {
    /* If there's an option and a define, the option overrides the
       define */
    int ret = RAND_egd(data->set.ssl.egdsocket?data->set.ssl.egdsocket:EGD_SOCKET);
    if(-1 != ret) {
      nread += ret;
      if(seed_enough(conn, nread))
        return nread;
    }
  }
#endif

  /* If we get here, it means we need to seed the PRNG using a "silly"
     approach! */
#ifdef HAVE_RAND_SCREEN
  /* This one gets a random value by reading the currently shown screen */
  RAND_screen();
  nread = 100; /* just a value */
#else
  {
    int len;
    char *area = Curl_FormBoundary();
    if(!area)
      return 3; /* out of memory */
	
    len = strlen(area);
    RAND_seed(area, len);

    free(area); /* now remove the random junk */
  }
#endif

  /* generates a default path for the random seed file */
  buf[0]=0; /* blank it first */
  RAND_file_name(buf, BUFSIZE);
  if ( buf[0] ) {
    /* we got a file name to try */
    nread += RAND_load_file(buf, 16384);
    if(seed_enough(conn, nread))
      return nread;
  }

  infof(conn->data, "Your connection is using a weak random seed!\n");
  return nread;
}

static
int cert_stuff(struct connectdata *conn,
               char *cert_file,
               char *key_file)
{
  struct SessionHandle *data = conn->data;
  if (cert_file != NULL) {
    SSL *ssl;
    X509 *x509;

    if(data->set.cert_passwd) {
#ifndef HAVE_USERDATA_IN_PWD_CALLBACK
      /*
       * If password has been given, we store that in the global
       * area (*shudder*) for a while:
       */
      strcpy(global_passwd, data->set.cert_passwd);
#else
      /*
       * We set the password in the callback userdata
       */
      SSL_CTX_set_default_passwd_cb_userdata(conn->ssl.ctx, data->set.cert_passwd);
#endif
      /* Set passwd callback: */
      SSL_CTX_set_default_passwd_cb(conn->ssl.ctx, passwd_callback);
    }

    if (SSL_CTX_use_certificate_file(conn->ssl.ctx,
				     cert_file,
				     SSL_FILETYPE_PEM) <= 0) {
      failf(data, "unable to set certificate file (wrong password?)\n");
      return(0);
    }
    if (key_file == NULL)
      key_file=cert_file;

    if (SSL_CTX_use_PrivateKey_file(conn->ssl.ctx,
				    key_file,
				    SSL_FILETYPE_PEM) <= 0) {
      failf(data, "unable to set public key file\n");
      return(0);
    }
    
    ssl=SSL_new(conn->ssl.ctx);
    x509=SSL_get_certificate(ssl);
    
    if (x509 != NULL)
      EVP_PKEY_copy_parameters(X509_get_pubkey(x509),
			       SSL_get_privatekey(ssl));
    SSL_free(ssl);

    /* If we are using DSA, we can copy the parameters from
     * the private key */
		
    
    /* Now we know that a key and cert have been set against
     * the SSL context */
    if (!SSL_CTX_check_private_key(conn->ssl.ctx)) {
      failf(data, "Private key does not match the certificate public key\n");
      return(0);
    }
#ifndef HAVE_USERDATA_IN_PWD_CALLBACK    
    /* erase it now */
    memset(global_passwd, 0, sizeof(global_passwd));
#endif
  }
  return(1);
}

static
int cert_verify_callback(int ok, X509_STORE_CTX *ctx)
{
  X509 *err_cert;
  char buf[256];

  err_cert=X509_STORE_CTX_get_current_cert(ctx);
  X509_NAME_oneline(X509_get_subject_name(err_cert),buf,256);

  return ok;
}

#endif

#ifdef USE_SSLEAY
/* "global" init done? */
static int init_ssl=0;
#endif

/* Global init */
void Curl_SSL_init(void)
{
#ifdef USE_SSLEAY
  /* make sure this is only done once */
  if(0 != init_ssl)
    return;

  init_ssl++; /* never again */

  /* Lets get nice error messages */
  SSL_load_error_strings();

  /* Setup all the global SSL stuff */
  SSLeay_add_ssl_algorithms();
#else
  /* SSL disabled, do nothing */
#endif
}

/* Global cleanup */
void Curl_SSL_cleanup(void)
{
#ifdef USE_SSLEAY
  if(init_ssl) {
    /* only cleanup if we did a previous init */

    /* Free the SSL error strings */
    ERR_free_strings();
  
    /* EVP_cleanup() removes all ciphers and digests from the
       table. */
    EVP_cleanup();
  }
#else
  /* SSL disabled, do nothing */
#endif
}

#ifdef USE_SSLEAY

/*
 * This function is called when an SSL connection is closed.
 */
void Curl_SSL_Close(struct connectdata *conn)
{
  if (conn->ssl.use) {
    /*
      ERR_remove_state() frees the error queue associated with
      thread pid.  If pid == 0, the current thread will have its
      error queue removed.

      Since error queue data structures are allocated
      automatically for new threads, they must be freed when
      threads are terminated in oder to avoid memory leaks.
    */
    ERR_remove_state(0);

    if(conn->ssl.handle) {
      (void)SSL_shutdown(conn->ssl.handle);
      SSL_set_connect_state(conn->ssl.handle);

      SSL_free (conn->ssl.handle);
      conn->ssl.handle = NULL;
    }
    if(conn->ssl.ctx) {
      SSL_CTX_free (conn->ssl.ctx);
      conn->ssl.ctx = NULL;
    }
    conn->ssl.use = FALSE; /* get back to ordinary socket usage */
  }
}


/*
 * This sets up a session cache to the specified size.
 */
CURLcode Curl_SSL_InitSessions(struct SessionHandle *data, long amount)
{
  struct curl_ssl_session *session;

  if(data->state.session)
    /* this is just a precaution to prevent multiple inits */
    return CURLE_OK;

  session = (struct curl_ssl_session *)
    malloc(amount * sizeof(struct curl_ssl_session));
  if(!session)
    return CURLE_OUT_OF_MEMORY;

  /* "blank out" the newly allocated memory */
  memset(session, 0, amount * sizeof(struct curl_ssl_session));

  /* store the info in the SSL section */
  data->set.ssl.numsessions = amount;
  data->state.session = session;
  data->state.sessionage = 1; /* this is brand new */

  return CURLE_OK;
}

/*
 * Check if there's a session ID for the given connection in the cache,
 * and if there's one suitable, it is returned.
 */
static int Get_SSL_Session(struct connectdata *conn,
                           SSL_SESSION **ssl_sessionid)
{
  struct curl_ssl_session *check;
  struct SessionHandle *data = conn->data;
  long i;

  for(i=0; i< data->set.ssl.numsessions; i++) {
    check = &data->state.session[i];
    if(!check->sessionid)
      /* not session ID means blank entry */
      continue;
    if(strequal(conn->name, check->name) &&
       (conn->remote_port == check->remote_port) ) {
      /* yes, we have a session ID! */
      data->state.sessionage++;            /* increase general age */
      check->age = data->state.sessionage; /* set this as used in this age */
      *ssl_sessionid = check->sessionid;
      return FALSE;
    }
  }
  *ssl_sessionid = (SSL_SESSION *)NULL;
  return TRUE;
}

/*
 * Kill a single session ID entry in the cache.
 */
static int Kill_Single_Session(struct curl_ssl_session *session)
{
  if(session->sessionid) {
    /* defensive check */

    /* free the ID */
    SSL_SESSION_free(session->sessionid);
    session->sessionid=NULL;
    session->age = 0; /* fresh */
    free(session->name);
    session->name = NULL; /* no name */

    return 0; /* ok */
  }
  else
    return 1;
}

/*
 * This function is called when the 'data' struct is going away. Close
 * down everything and free all resources!
 */
int Curl_SSL_Close_All(struct SessionHandle *data)
{
  int i;

  if(data->state.session) {    
    for(i=0; i< data->set.ssl.numsessions; i++)
      /* the single-killer function handles empty table slots */
      Kill_Single_Session(&data->state.session[i]);
    
    /* free the cache data */
    free(data->state.session);
  }
  return 0;
}

/*
 * Extract the session id and store it in the session cache.
 */
static int Store_SSL_Session(struct connectdata *conn)
{
  SSL_SESSION *ssl_sessionid;
  struct curl_ssl_session *store;
  int i;
  struct SessionHandle *data=conn->data; /* the mother of all structs */
  int oldest_age=data->state.session[0].age; /* zero if unused */

  /* ask OpenSSL, say please */
  ssl_sessionid = SSL_get1_session(conn->ssl.handle);

  /* SSL_get1_session() will increment the reference
     count and the session will stay in memory until explicitly freed with
     SSL_SESSION_free(3), regardless of its state. */

  /* Now we should add the session ID and the host name to the cache, (remove
     the oldest if necessary) */

  /* find an empty slot for us, or find the oldest */
  for(i=0; (i<data->set.ssl.numsessions) && data->state.session[i].sessionid; i++) {
    if(data->state.session[i].age < oldest_age) {
      oldest_age = data->state.session[i].age;
      store = &data->state.session[i];
    }
  }
  if(i == data->set.ssl.numsessions)
    /* cache is full, we must "kill" the oldest entry! */
    Kill_Single_Session(store);
  else
    store = &data->state.session[i]; /* use this slot */
  
  /* now init the session struct wisely */
  store->sessionid = ssl_sessionid;
  store->age = data->state.sessionage;      /* set current age */
  store->name = strdup(conn->name);       /* clone host name */
  store->remote_port = conn->remote_port; /* port number */

  return 0;
}

#endif  

/* ====================================================== */
CURLcode
Curl_SSLConnect(struct connectdata *conn)
{
  CURLcode retcode = CURLE_OK;

#ifdef USE_SSLEAY
  struct SessionHandle *data = conn->data;
  int err;
  char * str;
  SSL_METHOD *req_method;
  SSL_SESSION *ssl_sessionid=NULL;

  /* mark this is being ssl enabled from here on out. */
  conn->ssl.use = TRUE;

  /* Make funny stuff to get random input */
  random_the_seed(conn);
    
  switch(data->set.ssl.version) {
  default:
    req_method = SSLv23_client_method();
    break;
  case 2:
    req_method = SSLv2_client_method();
    break;
  case 3:
    req_method = SSLv3_client_method();
    break;
  }
    
  conn->ssl.ctx = SSL_CTX_new(req_method);

  if(!conn->ssl.ctx) {
    failf(data, "SSL: couldn't create a context!");
    return CURLE_OUT_OF_MEMORY;
  }
    
  if(data->set.cert) {
    if (!cert_stuff(conn, data->set.cert, data->set.cert)) {
      /* failf() is already done in cert_stuff() */
      return CURLE_SSL_CONNECT_ERROR;
    }
  }

  if(data->set.ssl.verifypeer){
    SSL_CTX_set_verify(conn->ssl.ctx,
                       SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT|
                       SSL_VERIFY_CLIENT_ONCE,
                       cert_verify_callback);
    if (!SSL_CTX_load_verify_locations(conn->ssl.ctx,
                                       data->set.ssl.CAfile,
                                       data->set.ssl.CApath)) {
      failf(data,"error setting cerficate verify locations\n");
      return CURLE_SSL_CONNECT_ERROR;
    }
  }
  else
    SSL_CTX_set_verify(conn->ssl.ctx, SSL_VERIFY_NONE, cert_verify_callback);


  /* Lets make an SSL structure */
  conn->ssl.handle = SSL_new (conn->ssl.ctx);
  SSL_set_connect_state (conn->ssl.handle);

  conn->ssl.server_cert = 0x0;

  if(!conn->bits.reuse) {
    /* We're not re-using a connection, check if there's a cached ID we
       can/should use here! */
    if(!Get_SSL_Session(conn, &ssl_sessionid)) {
      /* we got a session id, use it! */
      SSL_set_session(conn->ssl.handle, ssl_sessionid);
      /* Informational message */
      infof (data, "SSL re-using session ID\n");
    }
  }

  /* pass the raw socket into the SSL layers */
  SSL_set_fd (conn->ssl.handle, conn->firstsocket);
  err = SSL_connect (conn->ssl.handle);

  if (-1 == err) {
    err = ERR_get_error(); 
    failf(data, "SSL: %s", ERR_error_string(err, NULL));
    return CURLE_SSL_CONNECT_ERROR;
  }

  /* Informational message */
  infof (data, "SSL connection using %s\n",
         SSL_get_cipher(conn->ssl.handle));

  if(!ssl_sessionid) {
    /* Since this is not a cached session ID, then we want to stach this one
       in the cache! */
    Store_SSL_Session(conn);
  }

  
  /* Get server's certificate (note: beware of dynamic allocation) - opt */
  /* major serious hack alert -- we should check certificates
   * to authenticate the server; otherwise we risk man-in-the-middle
   * attack
   */

  conn->ssl.server_cert = SSL_get_peer_certificate (conn->ssl.handle);
  if(!conn->ssl.server_cert) {
    failf(data, "SSL: couldn't get peer certificate!");
    return CURLE_SSL_PEER_CERTIFICATE;
  }
  infof (data, "Server certificate:\n");
  
  str = X509_NAME_oneline (X509_get_subject_name (conn->ssl.server_cert),
                           NULL, 0);
  if(!str) {
    failf(data, "SSL: couldn't get X509-subject!");
    X509_free(conn->ssl.server_cert);
    return CURLE_SSL_CONNECT_ERROR;
  }
  infof(data, "\t subject: %s\n", str);
  CRYPTO_free(str);

  if (data->set.ssl.verifyhost) {
    char peer_CN[257];
    if (X509_NAME_get_text_by_NID(X509_get_subject_name(conn->ssl.server_cert), NID_commonName, peer_CN, sizeof(peer_CN)) < 0) {
      failf(data, "SSL: unable to obtain common name from peer certificate");
      X509_free(conn->ssl.server_cert);
      return CURLE_SSL_PEER_CERTIFICATE;
    }

    if (!strequal(peer_CN, conn->hostname)) {
      if (data->set.ssl.verifyhost > 1) {
        failf(data, "SSL: certificate subject name '%s' does not match target host name '%s'",
            peer_CN, conn->hostname);
        X509_free(conn->ssl.server_cert);
        return CURLE_SSL_PEER_CERTIFICATE;
      }
      else
        infof(data, "\t common name: %s (does not match '%s')\n", peer_CN, conn->hostname);
    }
    else
      infof(data, "\t common name: %s (matched)\n", peer_CN);
  }

  str = X509_NAME_oneline (X509_get_issuer_name  (conn->ssl.server_cert),
                           NULL, 0);
  if(!str) {
    failf(data, "SSL: couldn't get X509-issuer name!");
    X509_free(conn->ssl.server_cert);
    return CURLE_SSL_CONNECT_ERROR;
  }
  infof(data, "\t issuer: %s\n", str);
  CRYPTO_free(str);

  /* We could do all sorts of certificate verification stuff here before
     deallocating the certificate. */

  if(data->set.ssl.verifypeer) {
    data->set.ssl.certverifyresult=SSL_get_verify_result(conn->ssl.handle);
    if (data->set.ssl.certverifyresult != X509_V_OK) {
      failf(data, "SSL certificate verify result: %d\n",
            data->set.ssl.certverifyresult);
      retcode = CURLE_SSL_PEER_CERTIFICATE;
    }
  }
  else
    data->set.ssl.certverifyresult=0;

  X509_free(conn->ssl.server_cert);
#else /* USE_SSLEAY */
  /* this is for "-ansi -Wall -pedantic" to stop complaining!   (rabe) */
  (void) conn;
#endif
  return retcode;
}

/*
 * local variables:
 * eval: (load-file "../curl-mode.el")
 * end:
 * vim600: et sw=2 ts=2 sts=2 tw=78 fdm=marker
 * vim<600: et sw=2 ts=2 sts=2 tw=78
 */