VirtualBox

source: vbox/trunk/src/libs/curl-7.87.0/lib/vtls/bearssl.c@ 98326

最後變更 在這個檔案從98326是 98326,由 vboxsync 提交於 2 年 前

curl-7.87.0: Applied and adjusted our curl changes to 7.83.1. bugref:10356

  • 屬性 svn:eol-style 設為 native
檔案大小: 37.4 KB
 
1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 2019 - 2022, Michael Forney, <[email protected]>
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24#include "curl_setup.h"
25
26#ifdef USE_BEARSSL
27
28#include <bearssl.h>
29
30#include "bearssl.h"
31#include "urldata.h"
32#include "sendf.h"
33#include "inet_pton.h"
34#include "vtls.h"
35#include "vtls_int.h"
36#include "connect.h"
37#include "select.h"
38#include "multiif.h"
39#include "curl_printf.h"
40#include "strcase.h"
41
42/* The last #include files should be: */
43#include "curl_memory.h"
44#include "memdebug.h"
45
46struct x509_context {
47 const br_x509_class *vtable;
48 br_x509_minimal_context minimal;
49 br_x509_decoder_context decoder;
50 bool verifyhost;
51 bool verifypeer;
52 int cert_num;
53};
54
55struct ssl_backend_data {
56 br_ssl_client_context ctx;
57 struct x509_context x509;
58 unsigned char buf[BR_SSL_BUFSIZE_BIDI];
59 br_x509_trust_anchor *anchors;
60 size_t anchors_len;
61 const char *protocols[2];
62 /* SSL client context is active */
63 bool active;
64 /* size of pending write, yet to be flushed */
65 size_t pending_write;
66};
67
68struct cafile_parser {
69 CURLcode err;
70 bool in_cert;
71 br_x509_decoder_context xc;
72 /* array of trust anchors loaded from CAfile */
73 br_x509_trust_anchor *anchors;
74 size_t anchors_len;
75 /* buffer for DN data */
76 unsigned char dn[1024];
77 size_t dn_len;
78};
79
80#define CAFILE_SOURCE_PATH 1
81#define CAFILE_SOURCE_BLOB 2
82struct cafile_source {
83 int type;
84 const char *data;
85 size_t len;
86};
87
88static void append_dn(void *ctx, const void *buf, size_t len)
89{
90 struct cafile_parser *ca = ctx;
91
92 if(ca->err != CURLE_OK || !ca->in_cert)
93 return;
94 if(sizeof(ca->dn) - ca->dn_len < len) {
95 ca->err = CURLE_FAILED_INIT;
96 return;
97 }
98 memcpy(ca->dn + ca->dn_len, buf, len);
99 ca->dn_len += len;
100}
101
102static void x509_push(void *ctx, const void *buf, size_t len)
103{
104 struct cafile_parser *ca = ctx;
105
106 if(ca->in_cert)
107 br_x509_decoder_push(&ca->xc, buf, len);
108}
109
110static CURLcode load_cafile(struct cafile_source *source,
111 br_x509_trust_anchor **anchors,
112 size_t *anchors_len)
113{
114 struct cafile_parser ca;
115 br_pem_decoder_context pc;
116 br_x509_trust_anchor *ta;
117 size_t ta_size;
118 br_x509_trust_anchor *new_anchors;
119 size_t new_anchors_len;
120 br_x509_pkey *pkey;
121 FILE *fp = 0;
122 unsigned char buf[BUFSIZ];
123 const unsigned char *p;
124 const char *name;
125 size_t n, i, pushed;
126
127 DEBUGASSERT(source->type == CAFILE_SOURCE_PATH
128 || source->type == CAFILE_SOURCE_BLOB);
129
130 if(source->type == CAFILE_SOURCE_PATH) {
131 fp = fopen(source->data, "rb");
132 if(!fp)
133 return CURLE_SSL_CACERT_BADFILE;
134 }
135
136 if(source->type == CAFILE_SOURCE_BLOB && source->len > (size_t)INT_MAX)
137 return CURLE_SSL_CACERT_BADFILE;
138
139 ca.err = CURLE_OK;
140 ca.in_cert = FALSE;
141 ca.anchors = NULL;
142 ca.anchors_len = 0;
143 br_pem_decoder_init(&pc);
144 br_pem_decoder_setdest(&pc, x509_push, &ca);
145 do {
146 if(source->type == CAFILE_SOURCE_PATH) {
147 n = fread(buf, 1, sizeof(buf), fp);
148 if(n == 0)
149 break;
150 p = buf;
151 }
152 else if(source->type == CAFILE_SOURCE_BLOB) {
153 n = source->len;
154 p = (unsigned char *) source->data;
155 }
156 while(n) {
157 pushed = br_pem_decoder_push(&pc, p, n);
158 if(ca.err)
159 goto fail;
160 p += pushed;
161 n -= pushed;
162
163 switch(br_pem_decoder_event(&pc)) {
164 case 0:
165 break;
166 case BR_PEM_BEGIN_OBJ:
167 name = br_pem_decoder_name(&pc);
168 if(strcmp(name, "CERTIFICATE") && strcmp(name, "X509 CERTIFICATE"))
169 break;
170 br_x509_decoder_init(&ca.xc, append_dn, &ca);
171 ca.in_cert = TRUE;
172 ca.dn_len = 0;
173 break;
174 case BR_PEM_END_OBJ:
175 if(!ca.in_cert)
176 break;
177 ca.in_cert = FALSE;
178 if(br_x509_decoder_last_error(&ca.xc)) {
179 ca.err = CURLE_SSL_CACERT_BADFILE;
180 goto fail;
181 }
182 /* add trust anchor */
183 if(ca.anchors_len == SIZE_MAX / sizeof(ca.anchors[0])) {
184 ca.err = CURLE_OUT_OF_MEMORY;
185 goto fail;
186 }
187 new_anchors_len = ca.anchors_len + 1;
188 new_anchors = realloc(ca.anchors,
189 new_anchors_len * sizeof(ca.anchors[0]));
190 if(!new_anchors) {
191 ca.err = CURLE_OUT_OF_MEMORY;
192 goto fail;
193 }
194 ca.anchors = new_anchors;
195 ca.anchors_len = new_anchors_len;
196 ta = &ca.anchors[ca.anchors_len - 1];
197 ta->dn.data = NULL;
198 ta->flags = 0;
199 if(br_x509_decoder_isCA(&ca.xc))
200 ta->flags |= BR_X509_TA_CA;
201 pkey = br_x509_decoder_get_pkey(&ca.xc);
202 if(!pkey) {
203 ca.err = CURLE_SSL_CACERT_BADFILE;
204 goto fail;
205 }
206 ta->pkey = *pkey;
207
208 /* calculate space needed for trust anchor data */
209 ta_size = ca.dn_len;
210 switch(pkey->key_type) {
211 case BR_KEYTYPE_RSA:
212 ta_size += pkey->key.rsa.nlen + pkey->key.rsa.elen;
213 break;
214 case BR_KEYTYPE_EC:
215 ta_size += pkey->key.ec.qlen;
216 break;
217 default:
218 ca.err = CURLE_FAILED_INIT;
219 goto fail;
220 }
221
222 /* fill in trust anchor DN and public key data */
223 ta->dn.data = malloc(ta_size);
224 if(!ta->dn.data) {
225 ca.err = CURLE_OUT_OF_MEMORY;
226 goto fail;
227 }
228 memcpy(ta->dn.data, ca.dn, ca.dn_len);
229 ta->dn.len = ca.dn_len;
230 switch(pkey->key_type) {
231 case BR_KEYTYPE_RSA:
232 ta->pkey.key.rsa.n = ta->dn.data + ta->dn.len;
233 memcpy(ta->pkey.key.rsa.n, pkey->key.rsa.n, pkey->key.rsa.nlen);
234 ta->pkey.key.rsa.e = ta->pkey.key.rsa.n + ta->pkey.key.rsa.nlen;
235 memcpy(ta->pkey.key.rsa.e, pkey->key.rsa.e, pkey->key.rsa.elen);
236 break;
237 case BR_KEYTYPE_EC:
238 ta->pkey.key.ec.q = ta->dn.data + ta->dn.len;
239 memcpy(ta->pkey.key.ec.q, pkey->key.ec.q, pkey->key.ec.qlen);
240 break;
241 }
242 break;
243 default:
244 ca.err = CURLE_SSL_CACERT_BADFILE;
245 goto fail;
246 }
247 }
248 } while(source->type != CAFILE_SOURCE_BLOB);
249 if(fp && ferror(fp))
250 ca.err = CURLE_READ_ERROR;
251 else if(ca.in_cert)
252 ca.err = CURLE_SSL_CACERT_BADFILE;
253
254fail:
255 if(fp)
256 fclose(fp);
257 if(ca.err == CURLE_OK) {
258 *anchors = ca.anchors;
259 *anchors_len = ca.anchors_len;
260 }
261 else {
262 for(i = 0; i < ca.anchors_len; ++i)
263 free(ca.anchors[i].dn.data);
264 free(ca.anchors);
265 }
266
267 return ca.err;
268}
269
270static void x509_start_chain(const br_x509_class **ctx,
271 const char *server_name)
272{
273 struct x509_context *x509 = (struct x509_context *)ctx;
274
275 if(!x509->verifypeer) {
276 x509->cert_num = 0;
277 return;
278 }
279
280 if(!x509->verifyhost)
281 server_name = NULL;
282 x509->minimal.vtable->start_chain(&x509->minimal.vtable, server_name);
283}
284
285static void x509_start_cert(const br_x509_class **ctx, uint32_t length)
286{
287 struct x509_context *x509 = (struct x509_context *)ctx;
288
289 if(!x509->verifypeer) {
290 /* Only decode the first cert in the chain to obtain the public key */
291 if(x509->cert_num == 0)
292 br_x509_decoder_init(&x509->decoder, NULL, NULL);
293 return;
294 }
295
296 x509->minimal.vtable->start_cert(&x509->minimal.vtable, length);
297}
298
299static void x509_append(const br_x509_class **ctx, const unsigned char *buf,
300 size_t len)
301{
302 struct x509_context *x509 = (struct x509_context *)ctx;
303
304 if(!x509->verifypeer) {
305 if(x509->cert_num == 0)
306 br_x509_decoder_push(&x509->decoder, buf, len);
307 return;
308 }
309
310 x509->minimal.vtable->append(&x509->minimal.vtable, buf, len);
311}
312
313static void x509_end_cert(const br_x509_class **ctx)
314{
315 struct x509_context *x509 = (struct x509_context *)ctx;
316
317 if(!x509->verifypeer) {
318 x509->cert_num++;
319 return;
320 }
321
322 x509->minimal.vtable->end_cert(&x509->minimal.vtable);
323}
324
325static unsigned x509_end_chain(const br_x509_class **ctx)
326{
327 struct x509_context *x509 = (struct x509_context *)ctx;
328
329 if(!x509->verifypeer) {
330 return br_x509_decoder_last_error(&x509->decoder);
331 }
332
333 return x509->minimal.vtable->end_chain(&x509->minimal.vtable);
334}
335
336static const br_x509_pkey *x509_get_pkey(const br_x509_class *const *ctx,
337 unsigned *usages)
338{
339 struct x509_context *x509 = (struct x509_context *)ctx;
340
341 if(!x509->verifypeer) {
342 /* Nothing in the chain is verified, just return the public key of the
343 first certificate and allow its usage for both TLS_RSA_* and
344 TLS_ECDHE_* */
345 if(usages)
346 *usages = BR_KEYTYPE_KEYX | BR_KEYTYPE_SIGN;
347 return br_x509_decoder_get_pkey(&x509->decoder);
348 }
349
350 return x509->minimal.vtable->get_pkey(&x509->minimal.vtable, usages);
351}
352
353static const br_x509_class x509_vtable = {
354 sizeof(struct x509_context),
355 x509_start_chain,
356 x509_start_cert,
357 x509_append,
358 x509_end_cert,
359 x509_end_chain,
360 x509_get_pkey
361};
362
363struct st_cipher {
364 const char *name; /* Cipher suite IANA name. It starts with "TLS_" prefix */
365 const char *alias_name; /* Alias name is the same as OpenSSL cipher name */
366 uint16_t num; /* BearSSL cipher suite */
367};
368
369/* Macro to initialize st_cipher data structure */
370#define CIPHER_DEF(num, alias) { #num, alias, BR_##num }
371
372static const struct st_cipher ciphertable[] = {
373 /* RFC 2246 TLS 1.0 */
374 CIPHER_DEF(TLS_RSA_WITH_3DES_EDE_CBC_SHA, /* 0x000A */
375 "DES-CBC3-SHA"),
376
377 /* RFC 3268 TLS 1.0 AES */
378 CIPHER_DEF(TLS_RSA_WITH_AES_128_CBC_SHA, /* 0x002F */
379 "AES128-SHA"),
380 CIPHER_DEF(TLS_RSA_WITH_AES_256_CBC_SHA, /* 0x0035 */
381 "AES256-SHA"),
382
383 /* RFC 5246 TLS 1.2 */
384 CIPHER_DEF(TLS_RSA_WITH_AES_128_CBC_SHA256, /* 0x003C */
385 "AES128-SHA256"),
386 CIPHER_DEF(TLS_RSA_WITH_AES_256_CBC_SHA256, /* 0x003D */
387 "AES256-SHA256"),
388
389 /* RFC 5288 TLS 1.2 AES GCM */
390 CIPHER_DEF(TLS_RSA_WITH_AES_128_GCM_SHA256, /* 0x009C */
391 "AES128-GCM-SHA256"),
392 CIPHER_DEF(TLS_RSA_WITH_AES_256_GCM_SHA384, /* 0x009D */
393 "AES256-GCM-SHA384"),
394
395 /* RFC 4492 TLS 1.0 ECC */
396 CIPHER_DEF(TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA, /* 0xC003 */
397 "ECDH-ECDSA-DES-CBC3-SHA"),
398 CIPHER_DEF(TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA, /* 0xC004 */
399 "ECDH-ECDSA-AES128-SHA"),
400 CIPHER_DEF(TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA, /* 0xC005 */
401 "ECDH-ECDSA-AES256-SHA"),
402 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA, /* 0xC008 */
403 "ECDHE-ECDSA-DES-CBC3-SHA"),
404 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, /* 0xC009 */
405 "ECDHE-ECDSA-AES128-SHA"),
406 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, /* 0xC00A */
407 "ECDHE-ECDSA-AES256-SHA"),
408 CIPHER_DEF(TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA, /* 0xC00D */
409 "ECDH-RSA-DES-CBC3-SHA"),
410 CIPHER_DEF(TLS_ECDH_RSA_WITH_AES_128_CBC_SHA, /* 0xC00E */
411 "ECDH-RSA-AES128-SHA"),
412 CIPHER_DEF(TLS_ECDH_RSA_WITH_AES_256_CBC_SHA, /* 0xC00F */
413 "ECDH-RSA-AES256-SHA"),
414 CIPHER_DEF(TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, /* 0xC012 */
415 "ECDHE-RSA-DES-CBC3-SHA"),
416 CIPHER_DEF(TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, /* 0xC013 */
417 "ECDHE-RSA-AES128-SHA"),
418 CIPHER_DEF(TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, /* 0xC014 */
419 "ECDHE-RSA-AES256-SHA"),
420
421 /* RFC 5289 TLS 1.2 ECC HMAC SHA256/384 */
422 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, /* 0xC023 */
423 "ECDHE-ECDSA-AES128-SHA256"),
424 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384, /* 0xC024 */
425 "ECDHE-ECDSA-AES256-SHA384"),
426 CIPHER_DEF(TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256, /* 0xC025 */
427 "ECDH-ECDSA-AES128-SHA256"),
428 CIPHER_DEF(TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384, /* 0xC026 */
429 "ECDH-ECDSA-AES256-SHA384"),
430 CIPHER_DEF(TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, /* 0xC027 */
431 "ECDHE-RSA-AES128-SHA256"),
432 CIPHER_DEF(TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, /* 0xC028 */
433 "ECDHE-RSA-AES256-SHA384"),
434 CIPHER_DEF(TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256, /* 0xC029 */
435 "ECDH-RSA-AES128-SHA256"),
436 CIPHER_DEF(TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384, /* 0xC02A */
437 "ECDH-RSA-AES256-SHA384"),
438
439 /* RFC 5289 TLS 1.2 GCM */
440 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, /* 0xC02B */
441 "ECDHE-ECDSA-AES128-GCM-SHA256"),
442 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, /* 0xC02C */
443 "ECDHE-ECDSA-AES256-GCM-SHA384"),
444 CIPHER_DEF(TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256, /* 0xC02D */
445 "ECDH-ECDSA-AES128-GCM-SHA256"),
446 CIPHER_DEF(TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384, /* 0xC02E */
447 "ECDH-ECDSA-AES256-GCM-SHA384"),
448 CIPHER_DEF(TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, /* 0xC02F */
449 "ECDHE-RSA-AES128-GCM-SHA256"),
450 CIPHER_DEF(TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, /* 0xC030 */
451 "ECDHE-RSA-AES256-GCM-SHA384"),
452 CIPHER_DEF(TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256, /* 0xC031 */
453 "ECDH-RSA-AES128-GCM-SHA256"),
454 CIPHER_DEF(TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384, /* 0xC032 */
455 "ECDH-RSA-AES256-GCM-SHA384"),
456#ifdef BR_TLS_RSA_WITH_AES_128_CCM
457
458 /* RFC 6655 TLS 1.2 CCM
459 Supported since BearSSL 0.6 */
460 CIPHER_DEF(TLS_RSA_WITH_AES_128_CCM, /* 0xC09C */
461 "AES128-CCM"),
462 CIPHER_DEF(TLS_RSA_WITH_AES_256_CCM, /* 0xC09D */
463 "AES256-CCM"),
464 CIPHER_DEF(TLS_RSA_WITH_AES_128_CCM_8, /* 0xC0A0 */
465 "AES128-CCM8"),
466 CIPHER_DEF(TLS_RSA_WITH_AES_256_CCM_8, /* 0xC0A1 */
467 "AES256-CCM8"),
468
469 /* RFC 7251 TLS 1.2 ECC CCM
470 Supported since BearSSL 0.6 */
471 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_128_CCM, /* 0xC0AC */
472 "ECDHE-ECDSA-AES128-CCM"),
473 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_256_CCM, /* 0xC0AD */
474 "ECDHE-ECDSA-AES256-CCM"),
475 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8, /* 0xC0AE */
476 "ECDHE-ECDSA-AES128-CCM8"),
477 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8, /* 0xC0AF */
478 "ECDHE-ECDSA-AES256-CCM8"),
479#endif
480
481 /* RFC 7905 TLS 1.2 ChaCha20-Poly1305
482 Supported since BearSSL 0.2 */
483 CIPHER_DEF(TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, /* 0xCCA8 */
484 "ECDHE-RSA-CHACHA20-POLY1305"),
485 CIPHER_DEF(TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, /* 0xCCA9 */
486 "ECDHE-ECDSA-CHACHA20-POLY1305"),
487};
488
489#define NUM_OF_CIPHERS (sizeof(ciphertable) / sizeof(ciphertable[0]))
490#define CIPHER_NAME_BUF_LEN 64
491
492static bool is_separator(char c)
493{
494 /* Return whether character is a cipher list separator. */
495 switch(c) {
496 case ' ':
497 case '\t':
498 case ':':
499 case ',':
500 case ';':
501 return true;
502 }
503 return false;
504}
505
506static CURLcode bearssl_set_selected_ciphers(struct Curl_easy *data,
507 br_ssl_engine_context *ssl_eng,
508 const char *ciphers)
509{
510 uint16_t selected_ciphers[NUM_OF_CIPHERS];
511 size_t selected_count = 0;
512 char cipher_name[CIPHER_NAME_BUF_LEN];
513 const char *cipher_start = ciphers;
514 const char *cipher_end;
515 size_t i, j;
516
517 if(!cipher_start)
518 return CURLE_SSL_CIPHER;
519
520 while(true) {
521 /* Extract the next cipher name from the ciphers string */
522 while(is_separator(*cipher_start))
523 ++cipher_start;
524 if(*cipher_start == '\0')
525 break;
526 cipher_end = cipher_start;
527 while(*cipher_end != '\0' && !is_separator(*cipher_end))
528 ++cipher_end;
529 j = cipher_end - cipher_start < CIPHER_NAME_BUF_LEN - 1 ?
530 cipher_end - cipher_start : CIPHER_NAME_BUF_LEN - 1;
531 strncpy(cipher_name, cipher_start, j);
532 cipher_name[j] = '\0';
533 cipher_start = cipher_end;
534
535 /* Lookup the cipher name in the table of available ciphers. If the cipher
536 name starts with "TLS_" we do the lookup by IANA name. Otherwise, we try
537 to match cipher name by an (OpenSSL) alias. */
538 if(strncasecompare(cipher_name, "TLS_", 4)) {
539 for(i = 0; i < NUM_OF_CIPHERS &&
540 !strcasecompare(cipher_name, ciphertable[i].name); ++i);
541 }
542 else {
543 for(i = 0; i < NUM_OF_CIPHERS &&
544 !strcasecompare(cipher_name, ciphertable[i].alias_name); ++i);
545 }
546 if(i == NUM_OF_CIPHERS) {
547 infof(data, "BearSSL: unknown cipher in list: %s", cipher_name);
548 continue;
549 }
550
551 /* No duplicates allowed */
552 for(j = 0; j < selected_count &&
553 selected_ciphers[j] != ciphertable[i].num; j++);
554 if(j < selected_count) {
555 infof(data, "BearSSL: duplicate cipher in list: %s", cipher_name);
556 continue;
557 }
558
559 DEBUGASSERT(selected_count < NUM_OF_CIPHERS);
560 selected_ciphers[selected_count] = ciphertable[i].num;
561 ++selected_count;
562 }
563
564 if(selected_count == 0) {
565 failf(data, "BearSSL: no supported cipher in list");
566 return CURLE_SSL_CIPHER;
567 }
568
569 br_ssl_engine_set_suites(ssl_eng, selected_ciphers, selected_count);
570 return CURLE_OK;
571}
572
573static CURLcode bearssl_connect_step1(struct Curl_cfilter *cf,
574 struct Curl_easy *data)
575{
576 struct ssl_connect_data *connssl = cf->ctx;
577 struct ssl_backend_data *backend = connssl->backend;
578 struct ssl_primary_config *conn_config = Curl_ssl_cf_get_primary_config(cf);
579 struct ssl_config_data *ssl_config = Curl_ssl_cf_get_config(cf, data);
580 const struct curl_blob *ca_info_blob = conn_config->ca_info_blob;
581 const char * const ssl_cafile =
582 /* CURLOPT_CAINFO_BLOB overrides CURLOPT_CAINFO */
583 (ca_info_blob ? NULL : conn_config->CAfile);
584 const char *hostname = connssl->hostname;
585 const bool verifypeer = conn_config->verifypeer;
586 const bool verifyhost = conn_config->verifyhost;
587 CURLcode ret;
588 unsigned version_min, version_max;
589#ifdef ENABLE_IPV6
590 struct in6_addr addr;
591#else
592 struct in_addr addr;
593#endif
594
595 DEBUGASSERT(backend);
596
597 switch(conn_config->version) {
598 case CURL_SSLVERSION_SSLv2:
599 failf(data, "BearSSL does not support SSLv2");
600 return CURLE_SSL_CONNECT_ERROR;
601 case CURL_SSLVERSION_SSLv3:
602 failf(data, "BearSSL does not support SSLv3");
603 return CURLE_SSL_CONNECT_ERROR;
604 case CURL_SSLVERSION_TLSv1_0:
605 version_min = BR_TLS10;
606 version_max = BR_TLS10;
607 break;
608 case CURL_SSLVERSION_TLSv1_1:
609 version_min = BR_TLS11;
610 version_max = BR_TLS11;
611 break;
612 case CURL_SSLVERSION_TLSv1_2:
613 version_min = BR_TLS12;
614 version_max = BR_TLS12;
615 break;
616 case CURL_SSLVERSION_DEFAULT:
617 case CURL_SSLVERSION_TLSv1:
618 version_min = BR_TLS10;
619 version_max = BR_TLS12;
620 break;
621 default:
622 failf(data, "BearSSL: unknown CURLOPT_SSLVERSION");
623 return CURLE_SSL_CONNECT_ERROR;
624 }
625
626 if(ca_info_blob) {
627 struct cafile_source source;
628 source.type = CAFILE_SOURCE_BLOB;
629 source.data = ca_info_blob->data;
630 source.len = ca_info_blob->len;
631
632 ret = load_cafile(&source, &backend->anchors, &backend->anchors_len);
633 if(ret != CURLE_OK) {
634 if(verifypeer) {
635 failf(data, "error importing CA certificate blob");
636 return ret;
637 }
638 /* Only warn if no certificate verification is required. */
639 infof(data, "error importing CA certificate blob, continuing anyway");
640 }
641 }
642
643 if(ssl_cafile) {
644 struct cafile_source source;
645 source.type = CAFILE_SOURCE_PATH;
646 source.data = ssl_cafile;
647 source.len = 0;
648
649 ret = load_cafile(&source, &backend->anchors, &backend->anchors_len);
650 if(ret != CURLE_OK) {
651 if(verifypeer) {
652 failf(data, "error setting certificate verify locations."
653 " CAfile: %s", ssl_cafile);
654 return ret;
655 }
656 infof(data, "error setting certificate verify locations,"
657 " continuing anyway:");
658 }
659 }
660
661 /* initialize SSL context */
662 br_ssl_client_init_full(&backend->ctx, &backend->x509.minimal,
663 backend->anchors, backend->anchors_len);
664 br_ssl_engine_set_versions(&backend->ctx.eng, version_min, version_max);
665 br_ssl_engine_set_buffer(&backend->ctx.eng, backend->buf,
666 sizeof(backend->buf), 1);
667
668 if(conn_config->cipher_list) {
669 /* Override the ciphers as specified. For the default cipher list see the
670 BearSSL source code of br_ssl_client_init_full() */
671 ret = bearssl_set_selected_ciphers(data, &backend->ctx.eng,
672 conn_config->cipher_list);
673 if(ret)
674 return ret;
675 }
676
677 /* initialize X.509 context */
678 backend->x509.vtable = &x509_vtable;
679 backend->x509.verifypeer = verifypeer;
680 backend->x509.verifyhost = verifyhost;
681 br_ssl_engine_set_x509(&backend->ctx.eng, &backend->x509.vtable);
682
683 if(ssl_config->primary.sessionid) {
684 void *session;
685
686 Curl_ssl_sessionid_lock(data);
687 if(!Curl_ssl_getsessionid(cf, data, &session, NULL)) {
688 br_ssl_engine_set_session_parameters(&backend->ctx.eng, session);
689 infof(data, "BearSSL: re-using session ID");
690 }
691 Curl_ssl_sessionid_unlock(data);
692 }
693
694 if(cf->conn->bits.tls_enable_alpn) {
695 int cur = 0;
696
697 /* NOTE: when adding more protocols here, increase the size of the
698 * protocols array in `struct ssl_backend_data`.
699 */
700
701#ifdef USE_HTTP2
702 if(data->state.httpwant >= CURL_HTTP_VERSION_2
703#ifndef CURL_DISABLE_PROXY
704 && (!Curl_ssl_cf_is_proxy(cf) || !cf->conn->bits.tunnel_proxy)
705#endif
706 ) {
707 backend->protocols[cur++] = ALPN_H2;
708 infof(data, VTLS_INFOF_ALPN_OFFER_1STR, ALPN_H2);
709 }
710#endif
711
712 backend->protocols[cur++] = ALPN_HTTP_1_1;
713 infof(data, VTLS_INFOF_ALPN_OFFER_1STR, ALPN_HTTP_1_1);
714
715 br_ssl_engine_set_protocol_names(&backend->ctx.eng,
716 backend->protocols, cur);
717 }
718
719 if((1 == Curl_inet_pton(AF_INET, hostname, &addr))
720#ifdef ENABLE_IPV6
721 || (1 == Curl_inet_pton(AF_INET6, hostname, &addr))
722#endif
723 ) {
724 if(verifyhost) {
725 failf(data, "BearSSL: "
726 "host verification of IP address is not supported");
727 return CURLE_PEER_FAILED_VERIFICATION;
728 }
729 hostname = NULL;
730 }
731 else {
732 char *snihost = Curl_ssl_snihost(data, hostname, NULL);
733 if(!snihost) {
734 failf(data, "Failed to set SNI");
735 return CURLE_SSL_CONNECT_ERROR;
736 }
737 hostname = snihost;
738 }
739
740 /* give application a chance to interfere with SSL set up. */
741 if(data->set.ssl.fsslctx) {
742 Curl_set_in_callback(data, true);
743 ret = (*data->set.ssl.fsslctx)(data, &backend->ctx,
744 data->set.ssl.fsslctxp);
745 Curl_set_in_callback(data, false);
746 if(ret) {
747 failf(data, "BearSSL: error signaled by ssl ctx callback");
748 return ret;
749 }
750 }
751
752 if(!br_ssl_client_reset(&backend->ctx, hostname, 1))
753 return CURLE_FAILED_INIT;
754 backend->active = TRUE;
755
756 connssl->connecting_state = ssl_connect_2;
757
758 return CURLE_OK;
759}
760
761static CURLcode bearssl_run_until(struct Curl_cfilter *cf,
762 struct Curl_easy *data,
763 unsigned target)
764{
765 struct ssl_connect_data *connssl = cf->ctx;
766 struct ssl_backend_data *backend = connssl->backend;
767 unsigned state;
768 unsigned char *buf;
769 size_t len;
770 ssize_t ret;
771 CURLcode result;
772 int err;
773
774 DEBUGASSERT(backend);
775
776 for(;;) {
777 state = br_ssl_engine_current_state(&backend->ctx.eng);
778 if(state & BR_SSL_CLOSED) {
779 err = br_ssl_engine_last_error(&backend->ctx.eng);
780 switch(err) {
781 case BR_ERR_OK:
782 /* TLS close notify */
783 if(connssl->state != ssl_connection_complete) {
784 failf(data, "SSL: connection closed during handshake");
785 return CURLE_SSL_CONNECT_ERROR;
786 }
787 return CURLE_OK;
788 case BR_ERR_X509_EXPIRED:
789 failf(data, "SSL: X.509 verification: "
790 "certificate is expired or not yet valid");
791 return CURLE_PEER_FAILED_VERIFICATION;
792 case BR_ERR_X509_BAD_SERVER_NAME:
793 failf(data, "SSL: X.509 verification: "
794 "expected server name was not found in the chain");
795 return CURLE_PEER_FAILED_VERIFICATION;
796 case BR_ERR_X509_NOT_TRUSTED:
797 failf(data, "SSL: X.509 verification: "
798 "chain could not be linked to a trust anchor");
799 return CURLE_PEER_FAILED_VERIFICATION;
800 }
801 /* X.509 errors are documented to have the range 32..63 */
802 if(err >= 32 && err < 64)
803 return CURLE_PEER_FAILED_VERIFICATION;
804 return CURLE_SSL_CONNECT_ERROR;
805 }
806 if(state & target)
807 return CURLE_OK;
808 if(state & BR_SSL_SENDREC) {
809 buf = br_ssl_engine_sendrec_buf(&backend->ctx.eng, &len);
810 ret = Curl_conn_cf_send(cf->next, data, (char *)buf, len, &result);
811 if(ret <= 0) {
812 return result;
813 }
814 br_ssl_engine_sendrec_ack(&backend->ctx.eng, ret);
815 }
816 else if(state & BR_SSL_RECVREC) {
817 buf = br_ssl_engine_recvrec_buf(&backend->ctx.eng, &len);
818 ret = Curl_conn_cf_recv(cf->next, data, (char *)buf, len, &result);
819 if(ret == 0) {
820 failf(data, "SSL: EOF without close notify");
821 return CURLE_READ_ERROR;
822 }
823 if(ret <= 0) {
824 return result;
825 }
826 br_ssl_engine_recvrec_ack(&backend->ctx.eng, ret);
827 }
828 }
829}
830
831static CURLcode bearssl_connect_step2(struct Curl_cfilter *cf,
832 struct Curl_easy *data)
833{
834 struct ssl_connect_data *connssl = cf->ctx;
835 struct ssl_backend_data *backend = connssl->backend;
836 CURLcode ret;
837
838 DEBUGASSERT(backend);
839
840 ret = bearssl_run_until(cf, data, BR_SSL_SENDAPP | BR_SSL_RECVAPP);
841 if(ret == CURLE_AGAIN)
842 return CURLE_OK;
843 if(ret == CURLE_OK) {
844 if(br_ssl_engine_current_state(&backend->ctx.eng) == BR_SSL_CLOSED) {
845 failf(data, "SSL: connection closed during handshake");
846 return CURLE_SSL_CONNECT_ERROR;
847 }
848 connssl->connecting_state = ssl_connect_3;
849 }
850 return ret;
851}
852
853static CURLcode bearssl_connect_step3(struct Curl_cfilter *cf,
854 struct Curl_easy *data)
855{
856 struct ssl_connect_data *connssl = cf->ctx;
857 struct ssl_backend_data *backend = connssl->backend;
858 struct ssl_config_data *ssl_config = Curl_ssl_cf_get_config(cf, data);
859 CURLcode ret;
860
861 DEBUGASSERT(ssl_connect_3 == connssl->connecting_state);
862 DEBUGASSERT(backend);
863
864 if(cf->conn->bits.tls_enable_alpn) {
865 const char *protocol;
866
867 protocol = br_ssl_engine_get_selected_protocol(&backend->ctx.eng);
868 if(protocol) {
869 infof(data, VTLS_INFOF_ALPN_ACCEPTED_1STR, protocol);
870
871#ifdef USE_HTTP2
872 if(!strcmp(protocol, ALPN_H2))
873 cf->conn->alpn = CURL_HTTP_VERSION_2;
874 else
875#endif
876 if(!strcmp(protocol, ALPN_HTTP_1_1))
877 cf->conn->alpn = CURL_HTTP_VERSION_1_1;
878 else
879 infof(data, "ALPN, unrecognized protocol %s", protocol);
880 Curl_multiuse_state(data, cf->conn->alpn == CURL_HTTP_VERSION_2 ?
881 BUNDLE_MULTIPLEX : BUNDLE_NO_MULTIUSE);
882 }
883 else
884 infof(data, VTLS_INFOF_NO_ALPN);
885 }
886
887 if(ssl_config->primary.sessionid) {
888 bool incache;
889 bool added = FALSE;
890 void *oldsession;
891 br_ssl_session_parameters *session;
892
893 session = malloc(sizeof(*session));
894 if(!session)
895 return CURLE_OUT_OF_MEMORY;
896 br_ssl_engine_get_session_parameters(&backend->ctx.eng, session);
897 Curl_ssl_sessionid_lock(data);
898 incache = !(Curl_ssl_getsessionid(cf, data, &oldsession, NULL));
899 if(incache)
900 Curl_ssl_delsessionid(data, oldsession);
901 ret = Curl_ssl_addsessionid(cf, data, session, 0, &added);
902 Curl_ssl_sessionid_unlock(data);
903 if(!added)
904 free(session);
905 if(ret) {
906 return CURLE_OUT_OF_MEMORY;
907 }
908 }
909
910 connssl->connecting_state = ssl_connect_done;
911
912 return CURLE_OK;
913}
914
915static ssize_t bearssl_send(struct Curl_cfilter *cf, struct Curl_easy *data,
916 const void *buf, size_t len, CURLcode *err)
917{
918 struct ssl_connect_data *connssl = cf->ctx;
919 struct ssl_backend_data *backend = connssl->backend;
920 unsigned char *app;
921 size_t applen;
922
923 DEBUGASSERT(backend);
924
925 for(;;) {
926 *err = bearssl_run_until(cf, data, BR_SSL_SENDAPP);
927 if (*err != CURLE_OK)
928 return -1;
929 app = br_ssl_engine_sendapp_buf(&backend->ctx.eng, &applen);
930 if(!app) {
931 failf(data, "SSL: connection closed during write");
932 *err = CURLE_SEND_ERROR;
933 return -1;
934 }
935 if(backend->pending_write) {
936 applen = backend->pending_write;
937 backend->pending_write = 0;
938 return applen;
939 }
940 if(applen > len)
941 applen = len;
942 memcpy(app, buf, applen);
943 br_ssl_engine_sendapp_ack(&backend->ctx.eng, applen);
944 br_ssl_engine_flush(&backend->ctx.eng, 0);
945 backend->pending_write = applen;
946 }
947}
948
949static ssize_t bearssl_recv(struct Curl_cfilter *cf, struct Curl_easy *data,
950 char *buf, size_t len, CURLcode *err)
951{
952 struct ssl_connect_data *connssl = cf->ctx;
953 struct ssl_backend_data *backend = connssl->backend;
954 unsigned char *app;
955 size_t applen;
956
957 DEBUGASSERT(backend);
958
959 *err = bearssl_run_until(cf, data, BR_SSL_RECVAPP);
960 if(*err != CURLE_OK)
961 return -1;
962 app = br_ssl_engine_recvapp_buf(&backend->ctx.eng, &applen);
963 if(!app)
964 return 0;
965 if(applen > len)
966 applen = len;
967 memcpy(buf, app, applen);
968 br_ssl_engine_recvapp_ack(&backend->ctx.eng, applen);
969
970 return applen;
971}
972
973static CURLcode bearssl_connect_common(struct Curl_cfilter *cf,
974 struct Curl_easy *data,
975 bool nonblocking,
976 bool *done)
977{
978 CURLcode ret;
979 struct ssl_connect_data *connssl = cf->ctx;
980 curl_socket_t sockfd = cf->conn->sock[cf->sockindex];
981 timediff_t timeout_ms;
982 int what;
983
984 /* check if the connection has already been established */
985 if(ssl_connection_complete == connssl->state) {
986 *done = TRUE;
987 return CURLE_OK;
988 }
989
990 if(ssl_connect_1 == connssl->connecting_state) {
991 ret = bearssl_connect_step1(cf, data);
992 if(ret)
993 return ret;
994 }
995
996 while(ssl_connect_2 == connssl->connecting_state ||
997 ssl_connect_2_reading == connssl->connecting_state ||
998 ssl_connect_2_writing == connssl->connecting_state) {
999 /* check allowed time left */
1000 timeout_ms = Curl_timeleft(data, NULL, TRUE);
1001
1002 if(timeout_ms < 0) {
1003 /* no need to continue if time already is up */
1004 failf(data, "SSL connection timeout");
1005 return CURLE_OPERATION_TIMEDOUT;
1006 }
1007
1008 /* if ssl is expecting something, check if it's available. */
1009 if(ssl_connect_2_reading == connssl->connecting_state ||
1010 ssl_connect_2_writing == connssl->connecting_state) {
1011
1012 curl_socket_t writefd = ssl_connect_2_writing ==
1013 connssl->connecting_state?sockfd:CURL_SOCKET_BAD;
1014 curl_socket_t readfd = ssl_connect_2_reading ==
1015 connssl->connecting_state?sockfd:CURL_SOCKET_BAD;
1016
1017 what = Curl_socket_check(readfd, CURL_SOCKET_BAD, writefd,
1018 nonblocking?0:timeout_ms);
1019 if(what < 0) {
1020 /* fatal error */
1021 failf(data, "select/poll on SSL socket, errno: %d", SOCKERRNO);
1022 return CURLE_SSL_CONNECT_ERROR;
1023 }
1024 else if(0 == what) {
1025 if(nonblocking) {
1026 *done = FALSE;
1027 return CURLE_OK;
1028 }
1029 else {
1030 /* timeout */
1031 failf(data, "SSL connection timeout");
1032 return CURLE_OPERATION_TIMEDOUT;
1033 }
1034 }
1035 /* socket is readable or writable */
1036 }
1037
1038 /* Run transaction, and return to the caller if it failed or if this
1039 * connection is done nonblocking and this loop would execute again. This
1040 * permits the owner of a multi handle to abort a connection attempt
1041 * before step2 has completed while ensuring that a client using select()
1042 * or epoll() will always have a valid fdset to wait on.
1043 */
1044 ret = bearssl_connect_step2(cf, data);
1045 if(ret || (nonblocking &&
1046 (ssl_connect_2 == connssl->connecting_state ||
1047 ssl_connect_2_reading == connssl->connecting_state ||
1048 ssl_connect_2_writing == connssl->connecting_state)))
1049 return ret;
1050 }
1051
1052 if(ssl_connect_3 == connssl->connecting_state) {
1053 ret = bearssl_connect_step3(cf, data);
1054 if(ret)
1055 return ret;
1056 }
1057
1058 if(ssl_connect_done == connssl->connecting_state) {
1059 connssl->state = ssl_connection_complete;
1060 *done = TRUE;
1061 }
1062 else
1063 *done = FALSE;
1064
1065 /* Reset our connect state machine */
1066 connssl->connecting_state = ssl_connect_1;
1067
1068 return CURLE_OK;
1069}
1070
1071static size_t bearssl_version(char *buffer, size_t size)
1072{
1073 return msnprintf(buffer, size, "BearSSL");
1074}
1075
1076static bool bearssl_data_pending(struct Curl_cfilter *cf,
1077 const struct Curl_easy *data)
1078{
1079 struct ssl_connect_data *ctx = cf->ctx;
1080
1081 (void)data;
1082 DEBUGASSERT(ctx && ctx->backend);
1083 return br_ssl_engine_current_state(&ctx->backend->ctx.eng) & BR_SSL_RECVAPP;
1084}
1085
1086static CURLcode bearssl_random(struct Curl_easy *data UNUSED_PARAM,
1087 unsigned char *entropy, size_t length)
1088{
1089 static br_hmac_drbg_context ctx;
1090 static bool seeded = FALSE;
1091
1092 if(!seeded) {
1093 br_prng_seeder seeder;
1094
1095 br_hmac_drbg_init(&ctx, &br_sha256_vtable, NULL, 0);
1096 seeder = br_prng_seeder_system(NULL);
1097 if(!seeder || !seeder(&ctx.vtable))
1098 return CURLE_FAILED_INIT;
1099 seeded = TRUE;
1100 }
1101 br_hmac_drbg_generate(&ctx, entropy, length);
1102
1103 return CURLE_OK;
1104}
1105
1106static CURLcode bearssl_connect(struct Curl_cfilter *cf,
1107 struct Curl_easy *data)
1108{
1109 CURLcode ret;
1110 bool done = FALSE;
1111
1112 ret = bearssl_connect_common(cf, data, FALSE, &done);
1113 if(ret)
1114 return ret;
1115
1116 DEBUGASSERT(done);
1117
1118 return CURLE_OK;
1119}
1120
1121static CURLcode bearssl_connect_nonblocking(struct Curl_cfilter *cf,
1122 struct Curl_easy *data,
1123 bool *done)
1124{
1125 return bearssl_connect_common(cf, data, TRUE, done);
1126}
1127
1128static void *bearssl_get_internals(struct ssl_connect_data *connssl,
1129 CURLINFO info UNUSED_PARAM)
1130{
1131 struct ssl_backend_data *backend = connssl->backend;
1132 DEBUGASSERT(backend);
1133 return &backend->ctx;
1134}
1135
1136static void bearssl_close(struct Curl_cfilter *cf, struct Curl_easy *data)
1137{
1138 struct ssl_connect_data *connssl = cf->ctx;
1139 struct ssl_backend_data *backend = connssl->backend;
1140 size_t i;
1141
1142 DEBUGASSERT(backend);
1143
1144 if(backend->active) {
1145 backend->active = FALSE;
1146 br_ssl_engine_close(&backend->ctx.eng);
1147 (void)bearssl_run_until(cf, data, BR_SSL_CLOSED);
1148 }
1149 if(backend->anchors) {
1150 for(i = 0; i < backend->anchors_len; ++i)
1151 free(backend->anchors[i].dn.data);
1152 Curl_safefree(backend->anchors);
1153 }
1154}
1155
1156static void bearssl_session_free(void *ptr)
1157{
1158 free(ptr);
1159}
1160
1161static CURLcode bearssl_sha256sum(const unsigned char *input,
1162 size_t inputlen,
1163 unsigned char *sha256sum,
1164 size_t sha256len UNUSED_PARAM)
1165{
1166 br_sha256_context ctx;
1167
1168 br_sha256_init(&ctx);
1169 br_sha256_update(&ctx, input, inputlen);
1170 br_sha256_out(&ctx, sha256sum);
1171 return CURLE_OK;
1172}
1173
1174const struct Curl_ssl Curl_ssl_bearssl = {
1175 { CURLSSLBACKEND_BEARSSL, "bearssl" }, /* info */
1176 SSLSUPP_CAINFO_BLOB | SSLSUPP_SSL_CTX | SSLSUPP_HTTPS_PROXY,
1177 sizeof(struct ssl_backend_data),
1178
1179 Curl_none_init, /* init */
1180 Curl_none_cleanup, /* cleanup */
1181 bearssl_version, /* version */
1182 Curl_none_check_cxn, /* check_cxn */
1183 Curl_none_shutdown, /* shutdown */
1184 bearssl_data_pending, /* data_pending */
1185 bearssl_random, /* random */
1186 Curl_none_cert_status_request, /* cert_status_request */
1187 bearssl_connect, /* connect */
1188 bearssl_connect_nonblocking, /* connect_nonblocking */
1189 Curl_ssl_get_select_socks, /* getsock */
1190 bearssl_get_internals, /* get_internals */
1191 bearssl_close, /* close_one */
1192 Curl_none_close_all, /* close_all */
1193 bearssl_session_free, /* session_free */
1194 Curl_none_set_engine, /* set_engine */
1195 Curl_none_set_engine_default, /* set_engine_default */
1196 Curl_none_engines_list, /* engines_list */
1197 Curl_none_false_start, /* false_start */
1198 bearssl_sha256sum, /* sha256sum */
1199 NULL, /* associate_connection */
1200 NULL, /* disassociate_connection */
1201 NULL, /* free_multi_ssl_backend_data */
1202 bearssl_recv, /* recv decrypted data */
1203 bearssl_send, /* send data to encrypt */
1204};
1205
1206#endif /* USE_BEARSSL */
注意: 瀏覽 TracBrowser 來幫助您使用儲存庫瀏覽器

© 2025 Oracle Support Privacy / Do Not Sell My Info Terms of Use Trademark Policy Automated Access Etiquette