tortls_nss.c 19.7 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
/* Copyright (c) 2003, Roger Dingledine.
 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
 * Copyright (c) 2007-2018, The Tor Project, Inc. */
/* See LICENSE for licensing information */

/**
 * \file tortls_nss.c
 * \brief Wrapper functions to present a consistent interface to
 * TLS and SSL X.509 functions from NSS.
 **/

#include "orconfig.h"

#define TORTLS_PRIVATE
Nick Mathewson's avatar
Nick Mathewson committed
15
#define TOR_X509_PRIVATE
16

17
#ifdef _WIN32
18
19
20
21
22
23
24
25
  #include <winsock2.h>
  #include <ws2tcpip.h>
#endif

#include "lib/crypt_ops/crypto_cipher.h"
#include "lib/crypt_ops/crypto_rand.h"
#include "lib/crypt_ops/crypto_dh.h"
#include "lib/crypt_ops/crypto_util.h"
Nick Mathewson's avatar
Nick Mathewson committed
26
27
28
#include "lib/crypt_ops/crypto_nss_mgt.h"
#include "lib/string/printf.h"

29
#include "lib/tls/x509.h"
Nick Mathewson's avatar
Nick Mathewson committed
30
#include "lib/tls/x509_internal.h"
31
#include "lib/tls/tortls.h"
Nick Mathewson's avatar
Nick Mathewson committed
32
#include "lib/tls/tortls_st.h"
33
#include "lib/tls/tortls_internal.h"
34
#include "lib/tls/nss_countbytes.h"
35
36
#include "lib/log/util_bug.h"

37
DISABLE_GCC_WARNING(strict-prototypes)
Nick Mathewson's avatar
Nick Mathewson committed
38
#include <prio.h>
39
// For access to rar sockets.
Nick Mathewson's avatar
Nick Mathewson committed
40
41
42
43
44
#include <private/pprio.h>
#include <ssl.h>
#include <sslt.h>
#include <sslproto.h>
#include <certt.h>
45
ENABLE_GCC_WARNING(strict-prototypes)
Nick Mathewson's avatar
Nick Mathewson committed
46
47
48

static SECStatus always_accept_cert_cb(void *, PRFileDesc *, PRBool, PRBool);

49
50
51
52
53
54
55
56
MOCK_IMPL(void,
try_to_extract_certs_from_tls,(int severity, tor_tls_t *tls,
                               tor_x509_cert_impl_t **cert_out,
                               tor_x509_cert_impl_t **id_cert_out))
{
  tor_assert(tls);
  tor_assert(cert_out);
  tor_assert(id_cert_out);
Nick Mathewson's avatar
Nick Mathewson committed
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
  (void) severity;

  *cert_out = *id_cert_out = NULL;

  CERTCertificate *peer = SSL_PeerCertificate(tls->ssl);
  if (!peer)
    return;
  *cert_out = peer; /* Now owns pointer. */

  CERTCertList *chain = SSL_PeerCertificateChain(tls->ssl);
  CERTCertListNode *c = CERT_LIST_HEAD(chain);
  for (; !CERT_LIST_END(c, chain); c = CERT_LIST_NEXT(c)) {
    if (CERT_CompareCerts(c->cert, peer) == PR_FALSE) {
      *id_cert_out = CERT_DupCertificate(c->cert);
      break;
    }
  }
  CERT_DestroyCertList(chain);
}

static bool
we_like_ssl_cipher(SSLCipherAlgorithm ca)
{
  switch (ca) {
    case ssl_calg_null: return false;
    case ssl_calg_rc4: return false;
    case ssl_calg_rc2: return false;
    case ssl_calg_des: return false;
    case ssl_calg_3des: return false; /* ???? */
    case ssl_calg_idea: return false;
    case ssl_calg_fortezza: return false;
    case ssl_calg_camellia: return false;
    case ssl_calg_seed: return false;

    case ssl_calg_aes: return true;
    case ssl_calg_aes_gcm: return true;
    case ssl_calg_chacha20: return true;
    default: return true;
  }
}
static bool
we_like_ssl_kea(SSLKEAType kt)
{
  switch (kt) {
    case ssl_kea_null: return false;
    case ssl_kea_rsa: return false; /* ??? */
    case ssl_kea_fortezza: return false;
    case ssl_kea_ecdh_psk: return false;
    case ssl_kea_dh_psk: return false;

    case ssl_kea_dh: return true;
    case ssl_kea_ecdh: return true;
    case ssl_kea_tls13_any: return true;

    case ssl_kea_size: return true; /* prevent a warning. */
    default: return true;
  }
}

static bool
we_like_mac_algorithm(SSLMACAlgorithm ma)
{
  switch (ma) {
    case ssl_mac_null: return false;
    case ssl_mac_md5: return false;
    case ssl_hmac_md5: return false;

    case ssl_mac_sha: return true;
    case ssl_hmac_sha: return true;
    case ssl_hmac_sha256: return true;
    case ssl_mac_aead: return true;
    case ssl_hmac_sha384: return true;
    default: return true;
  }
}

static bool
we_like_auth_type(SSLAuthType at)
{
  switch (at) {
    case ssl_auth_null: return false;
    case ssl_auth_rsa_decrypt: return false;
    case ssl_auth_dsa: return false;
    case ssl_auth_kea: return false;

    case ssl_auth_ecdsa: return true;
    case ssl_auth_ecdh_rsa: return true;
    case ssl_auth_ecdh_ecdsa: return true;
    case ssl_auth_rsa_sign: return true;
    case ssl_auth_rsa_pss: return true;
    case ssl_auth_psk: return true;
    case ssl_auth_tls13_any: return true;

    case ssl_auth_size: return true; /* prevent a warning. */
    default: return true;
  }
153
154
155
156
157
158
}

tor_tls_context_t *
tor_tls_context_new(crypto_pk_t *identity,
                    unsigned int key_lifetime, unsigned flags, int is_client)
{
Nick Mathewson's avatar
Nick Mathewson committed
159
  SECStatus s;
160
  tor_assert(identity);
Nick Mathewson's avatar
Nick Mathewson committed
161

162
163
  tor_tls_init();

Nick Mathewson's avatar
Nick Mathewson committed
164
165
166
167
168
169
170
171
172
173
  tor_tls_context_t *ctx = tor_malloc_zero(sizeof(tor_tls_context_t));
  ctx->refcnt = 1;

  if (! is_client) {
    if (tor_tls_context_init_certificates(ctx, identity,
                                          key_lifetime, flags) < 0) {
      goto err;
    }
  }

Nick Mathewson's avatar
Nick Mathewson committed
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
  {
    /* Create the "model" PRFileDesc that we will use to base others on. */
    PRFileDesc *tcp = PR_NewTCPSocket();
    if (!tcp)
      goto err;

    ctx->ctx = SSL_ImportFD(NULL, tcp);
    if (!ctx->ctx) {
      PR_Close(tcp);
      goto err;
    }
  }

  // Configure the certificate.
  if (!is_client) {
    s = SSL_ConfigServerCert(ctx->ctx,
                             ctx->my_link_cert->cert,
                             (SECKEYPrivateKey *)
                               crypto_pk_get_nss_privkey(ctx->link_key),
                             NULL, /* ExtraServerCertData */
                             0 /* DataLen */);
    if (s != SECSuccess)
      goto err;
  }

  // We need a certificate from the other side.
  if (is_client) {
    // XXXX does this do anything?
    s = SSL_OptionSet(ctx->ctx, SSL_REQUIRE_CERTIFICATE, PR_TRUE);
    if (s != SECSuccess)
      goto err;
  }

  // Always accept other side's cert; we'll check it ourselves in goofy
  // tor ways.
  s = SSL_AuthCertificateHook(ctx->ctx, always_accept_cert_cb, NULL);

  // We allow simultaneous read and write.
  s = SSL_OptionSet(ctx->ctx, SSL_ENABLE_FDX, PR_TRUE);
  if (s != SECSuccess)
    goto err;
  // XXXX SSL_ROLLBACK_DETECTION??
  // XXXX SSL_ENABLE_ALPN??

  // Force client-mode or server_mode.
  s = SSL_OptionSet(ctx->ctx,
                is_client ? SSL_HANDSHAKE_AS_CLIENT : SSL_HANDSHAKE_AS_SERVER,
                PR_TRUE);
  if (s != SECSuccess)
    goto err;

  // Disable everything before TLS 1.0; support everything else.
  {
    SSLVersionRange vrange;
    memset(&vrange, 0, sizeof(vrange));
    s = SSL_VersionRangeGetSupported(ssl_variant_stream, &vrange);
    if (s != SECSuccess)
      goto err;
    if (vrange.min < SSL_LIBRARY_VERSION_TLS_1_0)
      vrange.min = SSL_LIBRARY_VERSION_TLS_1_0;
    s = SSL_VersionRangeSet(ctx->ctx, &vrange);
    if (s != SECSuccess)
      goto err;
  }

  // Only support strong ciphers.
  {
    const PRUint16 *ciphers = SSL_GetImplementedCiphers();
    const PRUint16 n_ciphers = SSL_GetNumImplementedCiphers();
    PRUint16 i;
    for (i = 0; i < n_ciphers; ++i) {
      SSLCipherSuiteInfo info;
      memset(&info, 0, sizeof(info));
      s = SSL_GetCipherSuiteInfo(ciphers[i], &info, sizeof(info));
      if (s != SECSuccess)
        goto err;
      if (BUG(info.cipherSuite != ciphers[i]))
        goto err;
      int disable = info.effectiveKeyBits < 128 ||
        info.macBits < 128 ||
        !we_like_ssl_cipher(info.symCipher) ||
        !we_like_ssl_kea(info.keaType) ||
        !we_like_mac_algorithm(info.macAlgorithm) ||
        !we_like_auth_type(info.authType)/* Requires NSS 3.24 */;

      s = SSL_CipherPrefSet(ctx->ctx, ciphers[i],
                            disable ? PR_FALSE : PR_TRUE);
      if (s != SECSuccess)
        goto err;
    }
  }

  // Only use DH and ECDH keys once.
  s = SSL_OptionSet(ctx->ctx, SSL_REUSE_SERVER_ECDHE_KEY, PR_FALSE);
  if (s != SECSuccess)
    goto err;

  // don't cache sessions.
  s = SSL_OptionSet(ctx->ctx, SSL_NO_CACHE, PR_TRUE);
  if (s != SECSuccess)
    goto err;

  // Enable DH.
  s = SSL_OptionSet(ctx->ctx, SSL_ENABLE_SERVER_DHE, PR_TRUE);
  if (s != SECSuccess)
    goto err;

  // Set DH and ECDH groups.
  SSLNamedGroup groups[] = {
      ssl_grp_ec_curve25519,
      ssl_grp_ec_secp256r1,
      ssl_grp_ec_secp224r1,
      ssl_grp_ffdhe_2048,
  };
  s = SSL_NamedGroupConfig(ctx->ctx, groups, ARRAY_LENGTH(groups));
  if (s != SECSuccess)
    goto err;

  // These features are off by default, so we don't need to disable them:
  //   Session tickets
  //   Renegotiation
  //   Compression
Nick Mathewson's avatar
Nick Mathewson committed
296
297
298
299
300
301
302

  goto done;
 err:
  tor_tls_context_decref(ctx);
  ctx = NULL;
 done:
  return ctx;
303
}
Nick Mathewson's avatar
Nick Mathewson committed
304

305
void
306
tor_tls_context_impl_free_(tor_tls_context_impl_t *ctx)
307
{
308
309
  if (!ctx)
    return;
Nick Mathewson's avatar
Nick Mathewson committed
310
  PR_Close(ctx);
311
}
312
313
314
315
316
317
318

void
tor_tls_get_state_description(tor_tls_t *tls, char *buf, size_t sz)
{
  (void)tls;
  (void)buf;
  (void)sz;
Nick Mathewson's avatar
Nick Mathewson committed
319
320
  // AFAICT, NSS doesn't expose its internal state.
  buf[0]=0;
321
322
323
324
325
}

void
tor_tls_init(void)
{
326
  tor_nss_countbytes_init();
327
}
Nick Mathewson's avatar
Nick Mathewson committed
328

329
330
331
332
void
tls_log_errors(tor_tls_t *tls, int severity, int domain,
               const char *doing)
{
333
334
335
336
  /* This implementation is a little different for NSS than it is for OpenSSL
     -- it logs the last error whether anything actually failed or not. So we
     have to only call it when something has gone wrong and we have a real
     error to report. */
Nick Mathewson's avatar
Nick Mathewson committed
337

338
  (void)tls;
Nick Mathewson's avatar
Nick Mathewson committed
339
340
  PRErrorCode code = PORT_GetError();

341
  const char *addr = tls ? tls->address : NULL;
Nick Mathewson's avatar
Nick Mathewson committed
342
343
344
345
346
347
348
349
350
351
  const char *string = PORT_ErrorToString(code);
  const char *name = PORT_ErrorToName(code);
  char buf[16];
  if (!string)
    string = "<unrecognized>";
  if (!name) {
    tor_snprintf(buf, sizeof(buf), "%d", code);
    name = buf;
  }

352
353
  const char *with = addr ? " with " : "";
  addr = addr ? addr : "";
Nick Mathewson's avatar
Nick Mathewson committed
354
  if (doing) {
355
356
    log_fn(severity, domain, "TLS error %s while %s%s%s: %s",
           name, doing, with, addr, string);
Nick Mathewson's avatar
Nick Mathewson committed
357
  } else {
358
359
    log_fn(severity, domain, "TLS error %s%s%s: %s", name, string,
           with, addr);
Nick Mathewson's avatar
Nick Mathewson committed
360
  }
361
362
363
}

tor_tls_t *
Nick Mathewson's avatar
Nick Mathewson committed
364
tor_tls_new(tor_socket_t sock, int is_server)
365
366
{
  (void)sock;
Nick Mathewson's avatar
Nick Mathewson committed
367
368
  tor_tls_context_t *ctx = tor_tls_context_get(is_server);

369
370
371
372
373
374
375
  PRFileDesc *tcp = NULL;
  if (SOCKET_OK(sock)) {
    tcp = PR_ImportTCPSocket(sock);
  } else {
    tcp = PR_NewTCPSocket();
  }

Nick Mathewson's avatar
Nick Mathewson committed
376
377
378
  if (!tcp)
    return NULL;

379
380
381
382
383
  PRFileDesc *count = tor_wrap_prfiledesc_with_byte_counter(tcp);
  if (! count)
    return NULL;

  PRFileDesc *ssl = SSL_ImportFD(ctx->ctx, count);
Nick Mathewson's avatar
Nick Mathewson committed
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
  if (!ssl) {
    PR_Close(tcp);
    return NULL;
  }

  tor_tls_t *tls = tor_malloc_zero(sizeof(tor_tls_t));
  tls->magic = TOR_TLS_MAGIC;
  tls->context = ctx;
  tor_tls_context_incref(ctx);
  tls->ssl = ssl;
  tls->socket = sock;
  tls->state = TOR_TLS_ST_HANDSHAKE;
  tls->isServer = !!is_server;

  if (!is_server) {
    /* Set a random SNI */
    char *fake_hostname = crypto_random_hostname(4,25, "www.",".com");
    SSL_SetURL(tls->ssl, fake_hostname);
    tor_free(fake_hostname);
  }
  SECStatus s = SSL_ResetHandshake(ssl, is_server ? PR_TRUE : PR_FALSE);
  if (s != SECSuccess) {
406
    tls_log_errors(tls, LOG_WARN, LD_CRYPTO, "resetting handshake state");
Nick Mathewson's avatar
Nick Mathewson committed
407
408
409
  }

  return tls;
410
}
Nick Mathewson's avatar
Nick Mathewson committed
411

412
413
414
415
416
417
418
419
void
tor_tls_set_renegotiate_callback(tor_tls_t *tls,
                                 void (*cb)(tor_tls_t *, void *arg),
                                 void *arg)
{
  tor_assert(tls);
  (void)cb;
  (void)arg;
Nick Mathewson's avatar
Nick Mathewson committed
420
421

  /* We don't support renegotiation-based TLS with NSS. */
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
/**
 * Tell the TLS library that the underlying socket for <b>tls</b> has been
 * closed, and the library should not attempt to free that socket itself.
 */
void
tor_tls_release_socket(tor_tls_t *tls)
{
  if (! tls)
    return;

  /* NSS doesn't have the equivalent of BIO_NO_CLOSE.  If you replace the
   * fd with something that's invalid, it causes a memory leak in PR_Close.
   *
   * If there were a way to put the PRFileDesc into the CLOSED state, that
   * would prevent it from closing its fd -- but there doesn't seem to be a
   * supported way to do that either.
   *
   * So instead: we make a new sacrificial socket, and replace the original
   * socket with that one. This seems to be the best we can do, until we
   * redesign the mainloop code enough to make this function unnecessary.
   */
  tor_socket_t sock =
    tor_open_socket_nonblocking(AF_INET, SOCK_STREAM, IPPROTO_TCP);
447
  if (! SOCKET_OK(sock)) {
448
449
450
451
452
453
454
    log_warn(LD_NET, "Out of sockets when trying to shut down an NSS "
             "connection");
    return;
  }

  PRFileDesc *tcp = PR_GetIdentitiesLayer(tls->ssl, PR_NSPR_IO_LAYER);
  if (BUG(! tcp)) {
455
    tor_close_socket(sock);
456
457
458
459
    return;
  }

  PR_ChangeFileDescNativeHandle(tcp, sock);
460
461
462
  /* Tell our socket accounting layer that we don't own this socket any more:
   * NSS is about to free it for us. */
  tor_release_socket_ownership(sock);
463
464
}

465
void
Nick Mathewson's avatar
Nick Mathewson committed
466
tor_tls_impl_free_(tor_tls_impl_t *tls)
467
{
Nick Mathewson's avatar
Nick Mathewson committed
468
469
  // XXXX This will close the underlying fd, which our OpenSSL version does
  // not do!
470
471
  if (!tls)
    return;
Nick Mathewson's avatar
Nick Mathewson committed
472
473

  PR_Close(tls);
474
475
476
477
478
}

int
tor_tls_peer_has_cert(tor_tls_t *tls)
{
Nick Mathewson's avatar
Nick Mathewson committed
479
480
481
482
  CERTCertificate *cert = SSL_PeerCertificate(tls->ssl);
  int result = (cert != NULL);
  CERT_DestroyCertificate(cert);
  return result;
483
}
Nick Mathewson's avatar
Nick Mathewson committed
484

485
486
487
MOCK_IMPL(tor_x509_cert_t *,
tor_tls_get_peer_cert,(tor_tls_t *tls))
{
Nick Mathewson's avatar
Nick Mathewson committed
488
489
490
491
492
  CERTCertificate *cert = SSL_PeerCertificate(tls->ssl);
  if (cert)
    return tor_x509_cert_new(cert);
  else
    return NULL;
493
}
Nick Mathewson's avatar
Nick Mathewson committed
494

495
496
497
498
MOCK_IMPL(tor_x509_cert_t *,
tor_tls_get_own_cert,(tor_tls_t *tls))
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
499
500
501
502
503
  CERTCertificate *cert = SSL_LocalCertificate(tls->ssl);
  if (cert)
    return tor_x509_cert_new(cert);
  else
    return NULL;
504
}
Nick Mathewson's avatar
Nick Mathewson committed
505

506
507
508
509
510
MOCK_IMPL(int,
tor_tls_read, (tor_tls_t *tls, char *cp, size_t len))
{
  tor_assert(tls);
  tor_assert(cp);
Nick Mathewson's avatar
Nick Mathewson committed
511
512
513
514
515
516
517
518
519
520
521
522
523
  tor_assert(len < INT_MAX);

  PRInt32 rv = PR_Read(tls->ssl, cp, (int)len);
  // log_debug(LD_NET, "PR_Read(%zu) returned %d", n, (int)rv);
  if (rv > 0) {
    return rv;
  }
  if (rv == 0)
    return TOR_TLS_CLOSE;
  PRErrorCode err = PORT_GetError();
  if (err == PR_WOULD_BLOCK_ERROR) {
    return TOR_TLS_WANTREAD; // XXXX ????
  } else {
524
    tls_log_errors(tls, LOG_NOTICE, LD_CRYPTO, "reading"); // XXXX
Nick Mathewson's avatar
Nick Mathewson committed
525
526
    return TOR_TLS_ERROR_MISC; // ????
  }
527
}
Nick Mathewson's avatar
Nick Mathewson committed
528

529
530
531
532
int
tor_tls_write(tor_tls_t *tls, const char *cp, size_t n)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
  tor_assert(cp || n == 0);
  tor_assert(n < INT_MAX);

  PRInt32 rv = PR_Write(tls->ssl, cp, (int)n);
  // log_debug(LD_NET, "PR_Write(%zu) returned %d", n, (int)rv);
  if (rv > 0) {
    return rv;
  }
  if (rv == 0)
    return TOR_TLS_ERROR_MISC;
  PRErrorCode err = PORT_GetError();

  if (err == PR_WOULD_BLOCK_ERROR) {
    return TOR_TLS_WANTWRITE; // XXXX ????
  } else {
548
    tls_log_errors(tls, LOG_NOTICE, LD_CRYPTO, "writing"); // XXXX
Nick Mathewson's avatar
Nick Mathewson committed
549
550
    return TOR_TLS_ERROR_MISC; // ????
  }
551
}
Nick Mathewson's avatar
Nick Mathewson committed
552

553
554
555
556
int
tor_tls_handshake(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
557
558
559
560
561
562
563
564
565
566
567
568
  tor_assert(tls->state == TOR_TLS_ST_HANDSHAKE);

  SECStatus s = SSL_ForceHandshake(tls->ssl);
  if (s == SECSuccess) {
    tls->state = TOR_TLS_ST_OPEN;
    log_debug(LD_NET, "SSL handshake is supposedly complete.");
    return tor_tls_finish_handshake(tls);
  }
  if (PORT_GetError() == PR_WOULD_BLOCK_ERROR)
    return TOR_TLS_WANTREAD; /* XXXX What about wantwrite? */

  return TOR_TLS_ERROR_MISC; // XXXX
569
}
Nick Mathewson's avatar
Nick Mathewson committed
570

571
572
573
574
int
tor_tls_finish_handshake(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
575
576
577
  // We don't need to do any of the weird handshake nonsense stuff on NSS,
  // since we only support recent handshakes.
  return TOR_TLS_DONE;
578
}
Nick Mathewson's avatar
Nick Mathewson committed
579

580
581
582
583
void
tor_tls_unblock_renegotiation(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
584
  /* We don't support renegotiation with NSS. */
585
}
Nick Mathewson's avatar
Nick Mathewson committed
586

587
588
589
590
void
tor_tls_block_renegotiation(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
591
  /* We don't support renegotiation with NSS. */
592
}
Nick Mathewson's avatar
Nick Mathewson committed
593

594
595
596
597
void
tor_tls_assert_renegotiation_unblocked(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
598
  /* We don't support renegotiation with NSS. */
599
}
Nick Mathewson's avatar
Nick Mathewson committed
600

601
602
603
604
int
tor_tls_get_pending_bytes(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
605
606
  int n = SSL_DataPending(tls->ssl);
  if (n < 0) {
607
    tls_log_errors(tls, LOG_WARN, LD_CRYPTO, "looking up pending bytes");
Nick Mathewson's avatar
Nick Mathewson committed
608
609
610
    return 0;
  }
  return (int)n;
611
}
Nick Mathewson's avatar
Nick Mathewson committed
612

613
614
615
616
size_t
tor_tls_get_forced_write_size(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
617
  /* NSS doesn't have the same "forced write" restriction as openssl. */
618
619
  return 0;
}
Nick Mathewson's avatar
Nick Mathewson committed
620

621
622
623
624
625
626
627
void
tor_tls_get_n_raw_bytes(tor_tls_t *tls,
                        size_t *n_read, size_t *n_written)
{
  tor_assert(tls);
  tor_assert(n_read);
  tor_assert(n_written);
628
629
630
631
632
633
634
635
636
637
638
  uint64_t r, w;
  if (tor_get_prfiledesc_byte_counts(tls->ssl, &r, &w) < 0) {
    *n_read = *n_written = 0;
    return;
  }

  *n_read = (size_t)(r - tls->last_read_count);
  *n_written = (size_t)(w - tls->last_write_count);

  tls->last_read_count = r;
  tls->last_write_count = w;
639
640
641
642
643
644
645
646
647
648
649
650
}

int
tor_tls_get_buffer_sizes(tor_tls_t *tls,
                         size_t *rbuf_capacity, size_t *rbuf_bytes,
                         size_t *wbuf_capacity, size_t *wbuf_bytes)
{
  tor_assert(tls);
  tor_assert(rbuf_capacity);
  tor_assert(rbuf_bytes);
  tor_assert(wbuf_capacity);
  tor_assert(wbuf_bytes);
Nick Mathewson's avatar
Nick Mathewson committed
651
652

  /* This is an acceptable way to say "we can't measure this." */
653
654
  return -1;
}
Nick Mathewson's avatar
Nick Mathewson committed
655

656
657
658
MOCK_IMPL(double,
tls_get_write_overhead_ratio, (void))
{
Nick Mathewson's avatar
Nick Mathewson committed
659
660
661
  /* XXX We don't currently have a way to measure this in NSS; we could do that
   * XXX with a PRIO layer, but it'll take a little coding. */
  return 0.95;
662
663
664
665
666
667
}

int
tor_tls_used_v1_handshake(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
668
669
670
  /* We don't support or allow the V1 handshake with NSS.
   */
  return 0;
671
}
Nick Mathewson's avatar
Nick Mathewson committed
672

673
674
675
676
int
tor_tls_server_got_renegotiate(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
677
  return 0; /* We don't support renegotiation with NSS */
678
}
Nick Mathewson's avatar
Nick Mathewson committed
679

680
681
682
683
684
685
MOCK_IMPL(int,
tor_tls_cert_matches_key,(const tor_tls_t *tls,
                          const struct tor_x509_cert_t *cert))
{
  tor_assert(tls);
  tor_assert(cert);
Nick Mathewson's avatar
Nick Mathewson committed
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
  int rv = 0;

  CERTCertificate *peercert = SSL_PeerCertificate(tls->ssl);
  if (!peercert)
    goto done;
  CERTSubjectPublicKeyInfo *peer_info = &peercert->subjectPublicKeyInfo;
  CERTSubjectPublicKeyInfo *cert_info = &cert->cert->subjectPublicKeyInfo;
  rv = SECOID_CompareAlgorithmID(&peer_info->algorithm,
                                 &cert_info->algorithm) == 0 &&
       SECITEM_ItemsAreEqual(&peer_info->subjectPublicKey,
                             &cert_info->subjectPublicKey);

 done:
  if (peercert)
    CERT_DestroyCertificate(peercert);
  return rv;
702
}
Nick Mathewson's avatar
Nick Mathewson committed
703

704
705
706
707
708
MOCK_IMPL(int,
tor_tls_get_tlssecrets,(tor_tls_t *tls, uint8_t *secrets_out))
{
  tor_assert(tls);
  tor_assert(secrets_out);
Nick Mathewson's avatar
Nick Mathewson committed
709
710
711

  /* There's no way to get this information out of NSS. */

712
713
  return -1;
}
Nick Mathewson's avatar
Nick Mathewson committed
714

715
716
717
718
719
720
721
722
723
724
MOCK_IMPL(int,
tor_tls_export_key_material,(tor_tls_t *tls, uint8_t *secrets_out,
                             const uint8_t *context,
                             size_t context_len,
                             const char *label))
{
  tor_assert(tls);
  tor_assert(secrets_out);
  tor_assert(context);
  tor_assert(label);
Nick Mathewson's avatar
Nick Mathewson committed
725
726
  tor_assert(strlen(label) <= UINT_MAX);
  tor_assert(context_len <= UINT_MAX);
727

Nick Mathewson's avatar
Nick Mathewson committed
728
729
730
731
732
733
734
  SECStatus s;
  s = SSL_ExportKeyingMaterial(tls->ssl,
                               label, (unsigned)strlen(label),
                               PR_TRUE, context, (unsigned)context_len,
                               secrets_out, DIGEST256_LEN);

  return (s == SECSuccess) ? 0 : -1;
735
736
737
738
739
740
}

const char *
tor_tls_get_ciphersuite_name(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758

  SSLChannelInfo channel_info;
  SSLCipherSuiteInfo cipher_info;

  memset(&channel_info, 0, sizeof(channel_info));
  memset(&cipher_info, 0, sizeof(cipher_info));

  SECStatus s = SSL_GetChannelInfo(tls->ssl,
                                   &channel_info, sizeof(channel_info));
  if (s != SECSuccess)
    return NULL;

  s = SSL_GetCipherSuiteInfo(channel_info.cipherSuite,
                             &cipher_info, sizeof(cipher_info));
  if (s != SECSuccess)
    return NULL;

  return cipher_info.cipherSuiteName;
759
760
}

Nick Mathewson's avatar
Nick Mathewson committed
761
762
763
/** The group we should use for ecdhe when none was selected. */
#define SEC_OID_TOR_DEFAULT_ECDHE_GROUP SEC_OID_ANSIX962_EC_PRIME256V1

764
765
766
int
evaluate_ecgroup_for_tls(const char *ecgroup)
{
Nick Mathewson's avatar
Nick Mathewson committed
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
  SECOidTag tag;

  if (!ecgroup)
    tag = SEC_OID_TOR_DEFAULT_ECDHE_GROUP;
  else if (!strcasecmp(ecgroup, "P256"))
    tag = SEC_OID_ANSIX962_EC_PRIME256V1;
  else if (!strcasecmp(ecgroup, "P224"))
    tag = SEC_OID_SECG_EC_SECP224R1;
  else
    return 0;

  /* I don't think we need any additional tests here for NSS */
  (void) tag;

  return 1;
}

static SECStatus
always_accept_cert_cb(void *arg, PRFileDesc *ssl, PRBool checkSig,
                      PRBool isServer)
{
  (void)arg;
  (void)ssl;
  (void)checkSig;
  (void)isServer;
  return SECSuccess;
793
}