tortls_nss.c 18.2 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
18
19
20
21
22
23
24
25

#ifdef _WIN32 /*wrkard for dtls1.h >= 0.9.8m of "#include <winsock.h>"*/
  #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
34
35
#include "lib/tls/tortls_internal.h"
#include "lib/log/util_bug.h"

Nick Mathewson's avatar
Nick Mathewson committed
36
37
38
39
40
41
42
43
44
45
#include <prio.h>
// For access to raw sockets.
#include <private/pprio.h>
#include <ssl.h>
#include <sslt.h>
#include <sslproto.h>
#include <certt.h>

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

46
47
48
49
50
51
52
53
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
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
  (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;
  }
150
151
152
153
154
155
}

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
156
  SECStatus s;
157
  tor_assert(identity);
Nick Mathewson's avatar
Nick Mathewson committed
158
159
160
161
162
163
164
165
166
167
168

  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
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
  {
    /* 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
291
292
293
294
295
296
297

  goto done;
 err:
  tor_tls_context_decref(ctx);
  ctx = NULL;
 done:
  return ctx;
298
}
Nick Mathewson's avatar
Nick Mathewson committed
299

300
void
Nick Mathewson's avatar
Nick Mathewson committed
301
tor_tls_context_impl_free(tor_tls_context_impl_t *ctx)
302
{
Nick Mathewson's avatar
Nick Mathewson committed
303
  PR_Close(ctx);
304
}
305
306
307
308
309
310
311

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
312
313
  // AFAICT, NSS doesn't expose its internal state.
  buf[0]=0;
314
315
316
317
318
}

void
tor_tls_init(void)
{
Nick Mathewson's avatar
Nick Mathewson committed
319
  /* We don't have any global setup to do yet, but that will change */
320
}
Nick Mathewson's avatar
Nick Mathewson committed
321

322
323
324
325
void
tls_log_errors(tor_tls_t *tls, int severity, int domain,
               const char *doing)
{
Nick Mathewson's avatar
Nick Mathewson committed
326
327
328
  /* XXXX This implementation isn't right for NSS -- it logs the last error
     whether anything actually failed or not. */

329
  (void)tls;
Nick Mathewson's avatar
Nick Mathewson committed
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
  PRErrorCode code = PORT_GetError();

  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;
  }

  if (doing) {
    log_fn(severity, domain, "TLS error %s while %s: %s", name, doing, string);
  } else {
    log_fn(severity, domain, "TLS error %s: %s", name, string);
  }
347
348
349
}

tor_tls_t *
Nick Mathewson's avatar
Nick Mathewson committed
350
tor_tls_new(tor_socket_t sock, int is_server)
351
352
{
  (void)sock;
Nick Mathewson's avatar
Nick Mathewson committed
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
  tor_tls_context_t *ctx = tor_tls_context_get(is_server);

  PRFileDesc *tcp = PR_ImportTCPSocket(sock);
  if (!tcp)
    return NULL;

  PRFileDesc *ssl = SSL_ImportFD(ctx->ctx, tcp);
  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) {
    crypto_nss_log_errors(LOG_WARN, "resetting handshake state");
  }

  return tls;
386
}
Nick Mathewson's avatar
Nick Mathewson committed
387

388
389
390
391
392
393
394
395
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
396
397

  /* We don't support renegotiation-based TLS with NSS. */
398
399
400
}

void
Nick Mathewson's avatar
Nick Mathewson committed
401
tor_tls_impl_free_(tor_tls_impl_t *tls)
402
{
Nick Mathewson's avatar
Nick Mathewson committed
403
404
405
406
  // XXXX This will close the underlying fd, which our OpenSSL version does
  // not do!

  PR_Close(tls);
407
408
409
410
411
}

int
tor_tls_peer_has_cert(tor_tls_t *tls)
{
Nick Mathewson's avatar
Nick Mathewson committed
412
413
414
415
  CERTCertificate *cert = SSL_PeerCertificate(tls->ssl);
  int result = (cert != NULL);
  CERT_DestroyCertificate(cert);
  return result;
416
}
Nick Mathewson's avatar
Nick Mathewson committed
417

418
419
420
MOCK_IMPL(tor_x509_cert_t *,
tor_tls_get_peer_cert,(tor_tls_t *tls))
{
Nick Mathewson's avatar
Nick Mathewson committed
421
422
423
424
425
  CERTCertificate *cert = SSL_PeerCertificate(tls->ssl);
  if (cert)
    return tor_x509_cert_new(cert);
  else
    return NULL;
426
}
Nick Mathewson's avatar
Nick Mathewson committed
427

428
429
430
431
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
432
433
434
435
436
  CERTCertificate *cert = SSL_LocalCertificate(tls->ssl);
  if (cert)
    return tor_x509_cert_new(cert);
  else
    return NULL;
437
}
Nick Mathewson's avatar
Nick Mathewson committed
438

439
440
441
442
443
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
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
  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) {
    tls->n_read_since_last_check += rv;
    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 {
    crypto_nss_log_errors(LOG_NOTICE, "reading"); // XXXX
    return TOR_TLS_ERROR_MISC; // ????
  }
461
}
Nick Mathewson's avatar
Nick Mathewson committed
462

463
464
465
466
int
tor_tls_write(tor_tls_t *tls, const char *cp, size_t n)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
  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) {
    tls->n_written_since_last_check += rv;
    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 {
    crypto_nss_log_errors(LOG_NOTICE, "writing"); // XXXX
    return TOR_TLS_ERROR_MISC; // ????
  }
486
}
Nick Mathewson's avatar
Nick Mathewson committed
487

488
489
490
491
int
tor_tls_handshake(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
492
493
494
495
496
497
498
499
500
501
502
503
  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
504
}
Nick Mathewson's avatar
Nick Mathewson committed
505

506
507
508
509
int
tor_tls_finish_handshake(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
510
511
512
  // 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;
513
}
Nick Mathewson's avatar
Nick Mathewson committed
514

515
516
517
518
void
tor_tls_unblock_renegotiation(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
519
  /* We don't support renegotiation with NSS. */
520
}
Nick Mathewson's avatar
Nick Mathewson committed
521

522
523
524
525
void
tor_tls_block_renegotiation(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
526
  /* We don't support renegotiation with NSS. */
527
}
Nick Mathewson's avatar
Nick Mathewson committed
528

529
530
531
532
void
tor_tls_assert_renegotiation_unblocked(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
533
  /* We don't support renegotiation with NSS. */
534
}
Nick Mathewson's avatar
Nick Mathewson committed
535

536
537
538
539
int
tor_tls_shutdown(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
540
541
  /* XXXX This is not actually used, so I'm not implementing it.  We can
   * XXXX remove this function entirely someday. */
542
543
  return -1;
}
Nick Mathewson's avatar
Nick Mathewson committed
544

545
546
547
548
int
tor_tls_get_pending_bytes(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
549
550
551
552
553
554
  int n = SSL_DataPending(tls->ssl);
  if (n < 0) {
    crypto_nss_log_errors(LOG_WARN, "Looking up pending bytes");
    return 0;
  }
  return (int)n;
555
}
Nick Mathewson's avatar
Nick Mathewson committed
556

557
558
559
560
size_t
tor_tls_get_forced_write_size(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
561
  /* NSS doesn't have the same "forced write" restriction as openssl. */
562
563
  return 0;
}
Nick Mathewson's avatar
Nick Mathewson committed
564

565
566
567
568
569
570
571
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);
Nick Mathewson's avatar
Nick Mathewson committed
572
573
574
575
576
577
578
  /* XXXX We don't curently have a way to measure this information correctly
   * in NSS; we could do that with a PRIO layer, but it'll take a little
   * coding.  For now, we just track the number of bytes sent _in_ the TLS
   * stream.  Doing this will make our rate-limiting slightly inaccurate. */
  *n_read = tls->n_read_since_last_check;
  *n_written = tls->n_written_since_last_check;
  tls->n_read_since_last_check = tls->n_written_since_last_check = 0;
579
580
581
582
583
584
585
586
587
588
589
590
}

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
591
592

  /* This is an acceptable way to say "we can't measure this." */
593
594
  return -1;
}
Nick Mathewson's avatar
Nick Mathewson committed
595

596
597
598
MOCK_IMPL(double,
tls_get_write_overhead_ratio, (void))
{
Nick Mathewson's avatar
Nick Mathewson committed
599
600
601
  /* 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;
602
603
604
605
606
607
}

int
tor_tls_used_v1_handshake(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
608
609
610
  /* We don't support or allow the V1 handshake with NSS.
   */
  return 0;
611
}
Nick Mathewson's avatar
Nick Mathewson committed
612

613
614
615
616
int
tor_tls_server_got_renegotiate(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
617
  return 0; /* We don't support renegotiation with NSS */
618
}
Nick Mathewson's avatar
Nick Mathewson committed
619

620
621
622
623
624
625
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
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
  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;
642
}
Nick Mathewson's avatar
Nick Mathewson committed
643

644
645
646
647
648
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
649
650
651

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

652
653
  return -1;
}
Nick Mathewson's avatar
Nick Mathewson committed
654

655
656
657
658
659
660
661
662
663
664
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
665
666
  tor_assert(strlen(label) <= UINT_MAX);
  tor_assert(context_len <= UINT_MAX);
667

Nick Mathewson's avatar
Nick Mathewson committed
668
669
670
671
672
673
674
  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;
675
676
677
678
679
680
}

const char *
tor_tls_get_ciphersuite_name(tor_tls_t *tls)
{
  tor_assert(tls);
Nick Mathewson's avatar
Nick Mathewson committed
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698

  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;
699
700
}

Nick Mathewson's avatar
Nick Mathewson committed
701
702
703
/** The group we should use for ecdhe when none was selected. */
#define SEC_OID_TOR_DEFAULT_ECDHE_GROUP SEC_OID_ANSIX962_EC_PRIME256V1

704
705
706
int
evaluate_ecgroup_for_tls(const char *ecgroup)
{
Nick Mathewson's avatar
Nick Mathewson committed
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
  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;
733
}