1 /* $OpenBSD: ts_rsp_sign.c,v 1.23 2019/07/03 03:24:04 deraadt Exp $ */
2 /* Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL
3  * project 2002.
4  */
5 /* ====================================================================
6  * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    licensing@OpenSSL.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  *
53  * This product includes cryptographic software written by Eric Young
54  * (eay@cryptsoft.com).  This product includes software written by Tim
55  * Hudson (tjh@cryptsoft.com).
56  *
57  */
58 
59 #include <sys/time.h>
60 
61 #include <string.h>
62 
63 #include <openssl/err.h>
64 #include <openssl/objects.h>
65 #include <openssl/pkcs7.h>
66 #include <openssl/ts.h>
67 
68 /* Private function declarations. */
69 
70 static ASN1_INTEGER *def_serial_cb(struct TS_resp_ctx *, void *);
71 static int def_time_cb(struct TS_resp_ctx *, void *, time_t *sec, long *usec);
72 static int def_extension_cb(struct TS_resp_ctx *, X509_EXTENSION *, void *);
73 
74 static void TS_RESP_CTX_init(TS_RESP_CTX *ctx);
75 static void TS_RESP_CTX_cleanup(TS_RESP_CTX *ctx);
76 static int TS_RESP_check_request(TS_RESP_CTX *ctx);
77 static ASN1_OBJECT *TS_RESP_get_policy(TS_RESP_CTX *ctx);
78 static TS_TST_INFO *TS_RESP_create_tst_info(TS_RESP_CTX *ctx,
79     ASN1_OBJECT *policy);
80 static int TS_RESP_process_extensions(TS_RESP_CTX *ctx);
81 static int TS_RESP_sign(TS_RESP_CTX *ctx);
82 
83 static ESS_SIGNING_CERT *ESS_SIGNING_CERT_new_init(X509 *signcert,
84     STACK_OF(X509) *certs);
85 static ESS_CERT_ID *ESS_CERT_ID_new_init(X509 *cert, int issuer_needed);
86 static int TS_TST_INFO_content_new(PKCS7 *p7);
87 static int ESS_add_signing_cert(PKCS7_SIGNER_INFO *si, ESS_SIGNING_CERT *sc);
88 
89 static ASN1_GENERALIZEDTIME *TS_RESP_set_genTime_with_precision(
90     ASN1_GENERALIZEDTIME *, time_t, long, unsigned);
91 
92 /* Default callbacks for response generation. */
93 
94 static ASN1_INTEGER *
95 def_serial_cb(struct TS_resp_ctx *ctx, void *data)
96 {
97 	ASN1_INTEGER *serial = ASN1_INTEGER_new();
98 
99 	if (!serial)
100 		goto err;
101 	if (!ASN1_INTEGER_set(serial, 1))
102 		goto err;
103 	return serial;
104 
105 err:
106 	TSerror(ERR_R_MALLOC_FAILURE);
107 	TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
108 	    "Error during serial number generation.");
109 	return NULL;
110 }
111 
112 /* Use the gettimeofday function call. */
113 static int
114 def_time_cb(struct TS_resp_ctx *ctx, void *data, time_t *sec, long *usec)
115 {
116 	struct timeval tv;
117 
118 	if (gettimeofday(&tv, NULL) != 0) {
119 		TSerror(TS_R_TIME_SYSCALL_ERROR);
120 		TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
121 		    "Time is not available.");
122 		TS_RESP_CTX_add_failure_info(ctx, TS_INFO_TIME_NOT_AVAILABLE);
123 		return 0;
124 	}
125 	/* Return time to caller. */
126 	*sec = tv.tv_sec;
127 	*usec = tv.tv_usec;
128 
129 	return 1;
130 }
131 
132 static int
133 def_extension_cb(struct TS_resp_ctx *ctx, X509_EXTENSION *ext, void *data)
134 {
135 	/* No extensions are processed here. */
136 	TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
137 	    "Unsupported extension.");
138 	TS_RESP_CTX_add_failure_info(ctx, TS_INFO_UNACCEPTED_EXTENSION);
139 	return 0;
140 }
141 
142 /* TS_RESP_CTX management functions. */
143 
144 TS_RESP_CTX *
145 TS_RESP_CTX_new(void)
146 {
147 	TS_RESP_CTX *ctx;
148 
149 	if (!(ctx = calloc(1, sizeof(TS_RESP_CTX)))) {
150 		TSerror(ERR_R_MALLOC_FAILURE);
151 		return NULL;
152 	}
153 
154 	/* Setting default callbacks. */
155 	ctx->serial_cb = def_serial_cb;
156 	ctx->time_cb = def_time_cb;
157 	ctx->extension_cb = def_extension_cb;
158 
159 	return ctx;
160 }
161 
162 void
163 TS_RESP_CTX_free(TS_RESP_CTX *ctx)
164 {
165 	if (!ctx)
166 		return;
167 
168 	X509_free(ctx->signer_cert);
169 	EVP_PKEY_free(ctx->signer_key);
170 	sk_X509_pop_free(ctx->certs, X509_free);
171 	sk_ASN1_OBJECT_pop_free(ctx->policies, ASN1_OBJECT_free);
172 	ASN1_OBJECT_free(ctx->default_policy);
173 	sk_EVP_MD_free(ctx->mds);	/* No EVP_MD_free method exists. */
174 	ASN1_INTEGER_free(ctx->seconds);
175 	ASN1_INTEGER_free(ctx->millis);
176 	ASN1_INTEGER_free(ctx->micros);
177 	free(ctx);
178 }
179 
180 int
181 TS_RESP_CTX_set_signer_cert(TS_RESP_CTX *ctx, X509 *signer)
182 {
183 	if (X509_check_purpose(signer, X509_PURPOSE_TIMESTAMP_SIGN, 0) != 1) {
184 		TSerror(TS_R_INVALID_SIGNER_CERTIFICATE_PURPOSE);
185 		return 0;
186 	}
187 	X509_free(ctx->signer_cert);
188 	ctx->signer_cert = signer;
189 	CRYPTO_add(&ctx->signer_cert->references, +1, CRYPTO_LOCK_X509);
190 	return 1;
191 }
192 
193 int
194 TS_RESP_CTX_set_signer_key(TS_RESP_CTX *ctx, EVP_PKEY *key)
195 {
196 	EVP_PKEY_free(ctx->signer_key);
197 	ctx->signer_key = key;
198 	CRYPTO_add(&ctx->signer_key->references, +1, CRYPTO_LOCK_EVP_PKEY);
199 
200 	return 1;
201 }
202 
203 int
204 TS_RESP_CTX_set_def_policy(TS_RESP_CTX *ctx, const ASN1_OBJECT *def_policy)
205 {
206 	if (ctx->default_policy)
207 		ASN1_OBJECT_free(ctx->default_policy);
208 	if (!(ctx->default_policy = OBJ_dup(def_policy)))
209 		goto err;
210 	return 1;
211 
212 err:
213 	TSerror(ERR_R_MALLOC_FAILURE);
214 	return 0;
215 }
216 
217 int
218 TS_RESP_CTX_set_certs(TS_RESP_CTX *ctx, STACK_OF(X509) *certs)
219 {
220 	int i;
221 
222 	if (ctx->certs) {
223 		sk_X509_pop_free(ctx->certs, X509_free);
224 		ctx->certs = NULL;
225 	}
226 	if (!certs)
227 		return 1;
228 	if (!(ctx->certs = sk_X509_dup(certs))) {
229 		TSerror(ERR_R_MALLOC_FAILURE);
230 		return 0;
231 	}
232 	for (i = 0; i < sk_X509_num(ctx->certs); ++i) {
233 		X509 *cert = sk_X509_value(ctx->certs, i);
234 		CRYPTO_add(&cert->references, +1, CRYPTO_LOCK_X509);
235 	}
236 
237 	return 1;
238 }
239 
240 int
241 TS_RESP_CTX_add_policy(TS_RESP_CTX *ctx, const ASN1_OBJECT *policy)
242 {
243 	ASN1_OBJECT *copy = NULL;
244 
245 	/* Create new policy stack if necessary. */
246 	if (!ctx->policies && !(ctx->policies = sk_ASN1_OBJECT_new_null()))
247 		goto err;
248 	if (!(copy = OBJ_dup(policy)))
249 		goto err;
250 	if (!sk_ASN1_OBJECT_push(ctx->policies, copy))
251 		goto err;
252 
253 	return 1;
254 
255 err:
256 	TSerror(ERR_R_MALLOC_FAILURE);
257 	ASN1_OBJECT_free(copy);
258 	return 0;
259 }
260 
261 int
262 TS_RESP_CTX_add_md(TS_RESP_CTX *ctx, const EVP_MD *md)
263 {
264 	/* Create new md stack if necessary. */
265 	if (!ctx->mds && !(ctx->mds = sk_EVP_MD_new_null()))
266 		goto err;
267 	/* Add the shared md, no copy needed. */
268 	if (!sk_EVP_MD_push(ctx->mds, (EVP_MD *)md))
269 		goto err;
270 
271 	return 1;
272 
273 err:
274 	TSerror(ERR_R_MALLOC_FAILURE);
275 	return 0;
276 }
277 
278 #define TS_RESP_CTX_accuracy_free(ctx)		\
279 	ASN1_INTEGER_free(ctx->seconds);	\
280 	ctx->seconds = NULL;			\
281 	ASN1_INTEGER_free(ctx->millis);		\
282 	ctx->millis = NULL;			\
283 	ASN1_INTEGER_free(ctx->micros);		\
284 	ctx->micros = NULL;
285 
286 int
287 TS_RESP_CTX_set_accuracy(TS_RESP_CTX *ctx, int secs, int millis, int micros)
288 {
289 	TS_RESP_CTX_accuracy_free(ctx);
290 	if (secs && (!(ctx->seconds = ASN1_INTEGER_new()) ||
291 	    !ASN1_INTEGER_set(ctx->seconds, secs)))
292 		goto err;
293 	if (millis && (!(ctx->millis = ASN1_INTEGER_new()) ||
294 	    !ASN1_INTEGER_set(ctx->millis, millis)))
295 		goto err;
296 	if (micros && (!(ctx->micros = ASN1_INTEGER_new()) ||
297 	    !ASN1_INTEGER_set(ctx->micros, micros)))
298 		goto err;
299 
300 	return 1;
301 
302 err:
303 	TS_RESP_CTX_accuracy_free(ctx);
304 	TSerror(ERR_R_MALLOC_FAILURE);
305 	return 0;
306 }
307 
308 void
309 TS_RESP_CTX_add_flags(TS_RESP_CTX *ctx, int flags)
310 {
311 	ctx->flags |= flags;
312 }
313 
314 void
315 TS_RESP_CTX_set_serial_cb(TS_RESP_CTX *ctx, TS_serial_cb cb, void *data)
316 {
317 	ctx->serial_cb = cb;
318 	ctx->serial_cb_data = data;
319 }
320 
321 void
322 TS_RESP_CTX_set_extension_cb(TS_RESP_CTX *ctx, TS_extension_cb cb, void *data)
323 {
324 	ctx->extension_cb = cb;
325 	ctx->extension_cb_data = data;
326 }
327 
328 int
329 TS_RESP_CTX_set_status_info(TS_RESP_CTX *ctx, int status, const char *text)
330 {
331 	TS_STATUS_INFO *si = NULL;
332 	ASN1_UTF8STRING *utf8_text = NULL;
333 	int ret = 0;
334 
335 	if (!(si = TS_STATUS_INFO_new()))
336 		goto err;
337 	if (!ASN1_INTEGER_set(si->status, status))
338 		goto err;
339 	if (text) {
340 		if (!(utf8_text = ASN1_UTF8STRING_new()) ||
341 		    !ASN1_STRING_set(utf8_text, text, strlen(text)))
342 			goto err;
343 		if (!si->text && !(si->text = sk_ASN1_UTF8STRING_new_null()))
344 			goto err;
345 		if (!sk_ASN1_UTF8STRING_push(si->text, utf8_text))
346 			goto err;
347 		utf8_text = NULL;	/* Ownership is lost. */
348 	}
349 	if (!TS_RESP_set_status_info(ctx->response, si))
350 		goto err;
351 	ret = 1;
352 
353 err:
354 	if (!ret)
355 		TSerror(ERR_R_MALLOC_FAILURE);
356 	TS_STATUS_INFO_free(si);
357 	ASN1_UTF8STRING_free(utf8_text);
358 	return ret;
359 }
360 
361 int
362 TS_RESP_CTX_set_status_info_cond(TS_RESP_CTX *ctx, int status, const char *text)
363 {
364 	int ret = 1;
365 	TS_STATUS_INFO *si = TS_RESP_get_status_info(ctx->response);
366 
367 	if (ASN1_INTEGER_get(si->status) == TS_STATUS_GRANTED) {
368 		/* Status has not been set, set it now. */
369 		ret = TS_RESP_CTX_set_status_info(ctx, status, text);
370 	}
371 	return ret;
372 }
373 
374 int
375 TS_RESP_CTX_add_failure_info(TS_RESP_CTX *ctx, int failure)
376 {
377 	TS_STATUS_INFO *si = TS_RESP_get_status_info(ctx->response);
378 
379 	if (!si->failure_info && !(si->failure_info = ASN1_BIT_STRING_new()))
380 		goto err;
381 	if (!ASN1_BIT_STRING_set_bit(si->failure_info, failure, 1))
382 		goto err;
383 	return 1;
384 
385 err:
386 	TSerror(ERR_R_MALLOC_FAILURE);
387 	return 0;
388 }
389 
390 TS_REQ *
391 TS_RESP_CTX_get_request(TS_RESP_CTX *ctx)
392 {
393 	return ctx->request;
394 }
395 
396 TS_TST_INFO *
397 TS_RESP_CTX_get_tst_info(TS_RESP_CTX *ctx)
398 {
399 	return ctx->tst_info;
400 }
401 
402 int
403 TS_RESP_CTX_set_clock_precision_digits(TS_RESP_CTX *ctx, unsigned precision)
404 {
405 	if (precision > TS_MAX_CLOCK_PRECISION_DIGITS)
406 		return 0;
407 	ctx->clock_precision_digits = precision;
408 	return 1;
409 }
410 
411 /* Main entry method of the response generation. */
412 TS_RESP *
413 TS_RESP_create_response(TS_RESP_CTX *ctx, BIO *req_bio)
414 {
415 	ASN1_OBJECT *policy;
416 	TS_RESP *response;
417 	int result = 0;
418 
419 	TS_RESP_CTX_init(ctx);
420 
421 	/* Creating the response object. */
422 	if (!(ctx->response = TS_RESP_new())) {
423 		TSerror(ERR_R_MALLOC_FAILURE);
424 		goto end;
425 	}
426 
427 	/* Parsing DER request. */
428 	if (!(ctx->request = d2i_TS_REQ_bio(req_bio, NULL))) {
429 		TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
430 		    "Bad request format or "
431 		    "system error.");
432 		TS_RESP_CTX_add_failure_info(ctx, TS_INFO_BAD_DATA_FORMAT);
433 		goto end;
434 	}
435 
436 	/* Setting default status info. */
437 	if (!TS_RESP_CTX_set_status_info(ctx, TS_STATUS_GRANTED, NULL))
438 		goto end;
439 
440 	/* Checking the request format. */
441 	if (!TS_RESP_check_request(ctx))
442 		goto end;
443 
444 	/* Checking acceptable policies. */
445 	if (!(policy = TS_RESP_get_policy(ctx)))
446 		goto end;
447 
448 	/* Creating the TS_TST_INFO object. */
449 	if (!(ctx->tst_info = TS_RESP_create_tst_info(ctx, policy)))
450 		goto end;
451 
452 	/* Processing extensions. */
453 	if (!TS_RESP_process_extensions(ctx))
454 		goto end;
455 
456 	/* Generating the signature. */
457 	if (!TS_RESP_sign(ctx))
458 		goto end;
459 
460 	/* Everything was successful. */
461 	result = 1;
462 
463 end:
464 	if (!result) {
465 		TSerror(TS_R_RESPONSE_SETUP_ERROR);
466 		if (ctx->response != NULL) {
467 			if (TS_RESP_CTX_set_status_info_cond(ctx,
468 			    TS_STATUS_REJECTION, "Error during response "
469 			    "generation.") == 0) {
470 				TS_RESP_free(ctx->response);
471 				ctx->response = NULL;
472 			}
473 		}
474 	}
475 	response = ctx->response;
476 	ctx->response = NULL;	/* Ownership will be returned to caller. */
477 	TS_RESP_CTX_cleanup(ctx);
478 	return response;
479 }
480 
481 /* Initializes the variable part of the context. */
482 static void
483 TS_RESP_CTX_init(TS_RESP_CTX *ctx)
484 {
485 	ctx->request = NULL;
486 	ctx->response = NULL;
487 	ctx->tst_info = NULL;
488 }
489 
490 /* Cleans up the variable part of the context. */
491 static void
492 TS_RESP_CTX_cleanup(TS_RESP_CTX *ctx)
493 {
494 	TS_REQ_free(ctx->request);
495 	ctx->request = NULL;
496 	TS_RESP_free(ctx->response);
497 	ctx->response = NULL;
498 	TS_TST_INFO_free(ctx->tst_info);
499 	ctx->tst_info = NULL;
500 }
501 
502 /* Checks the format and content of the request. */
503 static int
504 TS_RESP_check_request(TS_RESP_CTX *ctx)
505 {
506 	TS_REQ *request = ctx->request;
507 	TS_MSG_IMPRINT *msg_imprint;
508 	X509_ALGOR *md_alg;
509 	int md_alg_id;
510 	const ASN1_OCTET_STRING *digest;
511 	EVP_MD *md = NULL;
512 	int i;
513 
514 	/* Checking request version. */
515 	if (TS_REQ_get_version(request) != 1) {
516 		TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
517 		    "Bad request version.");
518 		TS_RESP_CTX_add_failure_info(ctx, TS_INFO_BAD_REQUEST);
519 		return 0;
520 	}
521 
522 	/* Checking message digest algorithm. */
523 	msg_imprint = TS_REQ_get_msg_imprint(request);
524 	md_alg = TS_MSG_IMPRINT_get_algo(msg_imprint);
525 	md_alg_id = OBJ_obj2nid(md_alg->algorithm);
526 	for (i = 0; !md && i < sk_EVP_MD_num(ctx->mds); ++i) {
527 		EVP_MD *current_md = sk_EVP_MD_value(ctx->mds, i);
528 		if (md_alg_id == EVP_MD_type(current_md))
529 			md = current_md;
530 	}
531 	if (!md) {
532 		TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
533 		    "Message digest algorithm is "
534 		    "not supported.");
535 		TS_RESP_CTX_add_failure_info(ctx, TS_INFO_BAD_ALG);
536 		return 0;
537 	}
538 
539 	/* No message digest takes parameter. */
540 	if (md_alg->parameter &&
541 	    ASN1_TYPE_get(md_alg->parameter) != V_ASN1_NULL) {
542 		TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
543 		    "Superfluous message digest "
544 		    "parameter.");
545 		TS_RESP_CTX_add_failure_info(ctx, TS_INFO_BAD_ALG);
546 		return 0;
547 	}
548 	/* Checking message digest size. */
549 	digest = TS_MSG_IMPRINT_get_msg(msg_imprint);
550 	if (digest->length != EVP_MD_size(md)) {
551 		TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
552 		    "Bad message digest.");
553 		TS_RESP_CTX_add_failure_info(ctx, TS_INFO_BAD_DATA_FORMAT);
554 		return 0;
555 	}
556 
557 	return 1;
558 }
559 
560 /* Returns the TSA policy based on the requested and acceptable policies. */
561 static ASN1_OBJECT *
562 TS_RESP_get_policy(TS_RESP_CTX *ctx)
563 {
564 	ASN1_OBJECT *requested = TS_REQ_get_policy_id(ctx->request);
565 	ASN1_OBJECT *policy = NULL;
566 	int i;
567 
568 	if (ctx->default_policy == NULL) {
569 		TSerror(TS_R_INVALID_NULL_POINTER);
570 		return NULL;
571 	}
572 	/* Return the default policy if none is requested or the default is
573 	   requested. */
574 	if (!requested || !OBJ_cmp(requested, ctx->default_policy))
575 		policy = ctx->default_policy;
576 
577 	/* Check if the policy is acceptable. */
578 	for (i = 0; !policy && i < sk_ASN1_OBJECT_num(ctx->policies); ++i) {
579 		ASN1_OBJECT *current = sk_ASN1_OBJECT_value(ctx->policies, i);
580 		if (!OBJ_cmp(requested, current))
581 			policy = current;
582 	}
583 	if (!policy) {
584 		TSerror(TS_R_UNACCEPTABLE_POLICY);
585 		TS_RESP_CTX_set_status_info(ctx, TS_STATUS_REJECTION,
586 		    "Requested policy is not "
587 		    "supported.");
588 		TS_RESP_CTX_add_failure_info(ctx, TS_INFO_UNACCEPTED_POLICY);
589 	}
590 	return policy;
591 }
592 
593 /* Creates the TS_TST_INFO object based on the settings of the context. */
594 static TS_TST_INFO *
595 TS_RESP_create_tst_info(TS_RESP_CTX *ctx, ASN1_OBJECT *policy)
596 {
597 	int result = 0;
598 	TS_TST_INFO *tst_info = NULL;
599 	ASN1_INTEGER *serial = NULL;
600 	ASN1_GENERALIZEDTIME *asn1_time = NULL;
601 	time_t sec;
602 	long usec;
603 	TS_ACCURACY *accuracy = NULL;
604 	const ASN1_INTEGER *nonce;
605 	GENERAL_NAME *tsa_name = NULL;
606 
607 	if (!(tst_info = TS_TST_INFO_new()))
608 		goto end;
609 	if (!TS_TST_INFO_set_version(tst_info, 1))
610 		goto end;
611 	if (!TS_TST_INFO_set_policy_id(tst_info, policy))
612 		goto end;
613 	if (!TS_TST_INFO_set_msg_imprint(tst_info, ctx->request->msg_imprint))
614 		goto end;
615 	if (!(serial = (*ctx->serial_cb)(ctx, ctx->serial_cb_data)) ||
616 	    !TS_TST_INFO_set_serial(tst_info, serial))
617 		goto end;
618 	if (!(*ctx->time_cb)(ctx, ctx->time_cb_data, &sec, &usec) ||
619 	    !(asn1_time = TS_RESP_set_genTime_with_precision(NULL, sec, usec,
620 	    ctx->clock_precision_digits)) ||
621 	    !TS_TST_INFO_set_time(tst_info, asn1_time))
622 		goto end;
623 
624 	/* Setting accuracy if needed. */
625 	if ((ctx->seconds || ctx->millis || ctx->micros) &&
626 	    !(accuracy = TS_ACCURACY_new()))
627 		goto end;
628 
629 	if (ctx->seconds && !TS_ACCURACY_set_seconds(accuracy, ctx->seconds))
630 		goto end;
631 	if (ctx->millis && !TS_ACCURACY_set_millis(accuracy, ctx->millis))
632 		goto end;
633 	if (ctx->micros && !TS_ACCURACY_set_micros(accuracy, ctx->micros))
634 		goto end;
635 	if (accuracy && !TS_TST_INFO_set_accuracy(tst_info, accuracy))
636 		goto end;
637 
638 	/* Setting ordering. */
639 	if ((ctx->flags & TS_ORDERING) &&
640 	    !TS_TST_INFO_set_ordering(tst_info, 1))
641 		goto end;
642 
643 	/* Setting nonce if needed. */
644 	if ((nonce = TS_REQ_get_nonce(ctx->request)) != NULL &&
645 	    !TS_TST_INFO_set_nonce(tst_info, nonce))
646 		goto end;
647 
648 	/* Setting TSA name to subject of signer certificate. */
649 	if (ctx->flags & TS_TSA_NAME) {
650 		if (!(tsa_name = GENERAL_NAME_new()))
651 			goto end;
652 		tsa_name->type = GEN_DIRNAME;
653 		tsa_name->d.dirn =
654 		    X509_NAME_dup(ctx->signer_cert->cert_info->subject);
655 		if (!tsa_name->d.dirn)
656 			goto end;
657 		if (!TS_TST_INFO_set_tsa(tst_info, tsa_name))
658 			goto end;
659 	}
660 
661 	result = 1;
662 
663 end:
664 	if (!result) {
665 		TS_TST_INFO_free(tst_info);
666 		tst_info = NULL;
667 		TSerror(TS_R_TST_INFO_SETUP_ERROR);
668 		TS_RESP_CTX_set_status_info_cond(ctx, TS_STATUS_REJECTION,
669 		    "Error during TSTInfo "
670 		    "generation.");
671 	}
672 	GENERAL_NAME_free(tsa_name);
673 	TS_ACCURACY_free(accuracy);
674 	ASN1_GENERALIZEDTIME_free(asn1_time);
675 	ASN1_INTEGER_free(serial);
676 
677 	return tst_info;
678 }
679 
680 /* Processing the extensions of the request. */
681 static int
682 TS_RESP_process_extensions(TS_RESP_CTX *ctx)
683 {
684 	STACK_OF(X509_EXTENSION) *exts = TS_REQ_get_exts(ctx->request);
685 	int i;
686 	int ok = 1;
687 
688 	for (i = 0; ok && i < sk_X509_EXTENSION_num(exts); ++i) {
689 		X509_EXTENSION *ext = sk_X509_EXTENSION_value(exts, i);
690 		/* XXXXX The last argument was previously
691 		   (void *)ctx->extension_cb, but ISO C doesn't permit
692 		   converting a function pointer to void *.  For lack of
693 		   better information, I'm placing a NULL there instead.
694 		   The callback can pick its own address out from the ctx
695 		   anyway...
696 		*/
697 		ok = (*ctx->extension_cb)(ctx, ext, NULL);
698 	}
699 
700 	return ok;
701 }
702 
703 /* Functions for signing the TS_TST_INFO structure of the context. */
704 static int
705 TS_RESP_sign(TS_RESP_CTX *ctx)
706 {
707 	int ret = 0;
708 	PKCS7 *p7 = NULL;
709 	PKCS7_SIGNER_INFO *si;
710 	STACK_OF(X509) *certs;	/* Certificates to include in sc. */
711 	ESS_SIGNING_CERT *sc = NULL;
712 	ASN1_OBJECT *oid;
713 	BIO *p7bio = NULL;
714 	int i;
715 
716 	/* Check if signcert and pkey match. */
717 	if (!X509_check_private_key(ctx->signer_cert, ctx->signer_key)) {
718 		TSerror(TS_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
719 		goto err;
720 	}
721 
722 	/* Create a new PKCS7 signed object. */
723 	if (!(p7 = PKCS7_new())) {
724 		TSerror(ERR_R_MALLOC_FAILURE);
725 		goto err;
726 	}
727 	if (!PKCS7_set_type(p7, NID_pkcs7_signed))
728 		goto err;
729 
730 	/* Force SignedData version to be 3 instead of the default 1. */
731 	if (!ASN1_INTEGER_set(p7->d.sign->version, 3))
732 		goto err;
733 
734 	/* Add signer certificate and optional certificate chain. */
735 	if (TS_REQ_get_cert_req(ctx->request)) {
736 		PKCS7_add_certificate(p7, ctx->signer_cert);
737 		if (ctx->certs) {
738 			for (i = 0; i < sk_X509_num(ctx->certs); ++i) {
739 				X509 *cert = sk_X509_value(ctx->certs, i);
740 				PKCS7_add_certificate(p7, cert);
741 			}
742 		}
743 	}
744 
745 	/* Add a new signer info. */
746 	if (!(si = PKCS7_add_signature(p7, ctx->signer_cert,
747 	    ctx->signer_key, EVP_sha1()))) {
748 		TSerror(TS_R_PKCS7_ADD_SIGNATURE_ERROR);
749 		goto err;
750 	}
751 
752 	/* Add content type signed attribute to the signer info. */
753 	oid = OBJ_nid2obj(NID_id_smime_ct_TSTInfo);
754 	if (!PKCS7_add_signed_attribute(si, NID_pkcs9_contentType,
755 	    V_ASN1_OBJECT, oid)) {
756 		TSerror(TS_R_PKCS7_ADD_SIGNED_ATTR_ERROR);
757 		goto err;
758 	}
759 
760 	/* Create the ESS SigningCertificate attribute which contains
761 	   the signer certificate id and optionally the certificate chain. */
762 	certs = ctx->flags & TS_ESS_CERT_ID_CHAIN ? ctx->certs : NULL;
763 	if (!(sc = ESS_SIGNING_CERT_new_init(ctx->signer_cert, certs)))
764 		goto err;
765 
766 	/* Add SigningCertificate signed attribute to the signer info. */
767 	if (!ESS_add_signing_cert(si, sc)) {
768 		TSerror(TS_R_ESS_ADD_SIGNING_CERT_ERROR);
769 		goto err;
770 	}
771 
772 	/* Add a new empty NID_id_smime_ct_TSTInfo encapsulated content. */
773 	if (!TS_TST_INFO_content_new(p7))
774 		goto err;
775 
776 	/* Add the DER encoded tst_info to the PKCS7 structure. */
777 	if (!(p7bio = PKCS7_dataInit(p7, NULL))) {
778 		TSerror(ERR_R_MALLOC_FAILURE);
779 		goto err;
780 	}
781 
782 	/* Convert tst_info to DER. */
783 	if (!i2d_TS_TST_INFO_bio(p7bio, ctx->tst_info)) {
784 		TSerror(TS_R_TS_DATASIGN);
785 		goto err;
786 	}
787 
788 	/* Create the signature and add it to the signer info. */
789 	if (!PKCS7_dataFinal(p7, p7bio)) {
790 		TSerror(TS_R_TS_DATASIGN);
791 		goto err;
792 	}
793 
794 	/* Set new PKCS7 and TST_INFO objects. */
795 	TS_RESP_set_tst_info(ctx->response, p7, ctx->tst_info);
796 	p7 = NULL;		/* Ownership is lost. */
797 	ctx->tst_info = NULL;	/* Ownership is lost. */
798 
799 	ret = 1;
800 
801 err:
802 	if (!ret)
803 		TS_RESP_CTX_set_status_info_cond(ctx, TS_STATUS_REJECTION,
804 	    "Error during signature "
805 	    "generation.");
806 	BIO_free_all(p7bio);
807 	ESS_SIGNING_CERT_free(sc);
808 	PKCS7_free(p7);
809 	return ret;
810 }
811 
812 static ESS_SIGNING_CERT *
813 ESS_SIGNING_CERT_new_init(X509 *signcert, STACK_OF(X509) *certs)
814 {
815 	ESS_CERT_ID *cid;
816 	ESS_SIGNING_CERT *sc = NULL;
817 	int i;
818 
819 	/* Creating the ESS_CERT_ID stack. */
820 	if (!(sc = ESS_SIGNING_CERT_new()))
821 		goto err;
822 	if (!sc->cert_ids && !(sc->cert_ids = sk_ESS_CERT_ID_new_null()))
823 		goto err;
824 
825 	/* Adding the signing certificate id. */
826 	if (!(cid = ESS_CERT_ID_new_init(signcert, 0)) ||
827 	    !sk_ESS_CERT_ID_push(sc->cert_ids, cid))
828 		goto err;
829 	/* Adding the certificate chain ids. */
830 	for (i = 0; i < sk_X509_num(certs); ++i) {
831 		X509 *cert = sk_X509_value(certs, i);
832 		if (!(cid = ESS_CERT_ID_new_init(cert, 1)) ||
833 		    !sk_ESS_CERT_ID_push(sc->cert_ids, cid))
834 			goto err;
835 	}
836 
837 	return sc;
838 
839 err:
840 	ESS_SIGNING_CERT_free(sc);
841 	TSerror(ERR_R_MALLOC_FAILURE);
842 	return NULL;
843 }
844 
845 static ESS_CERT_ID *
846 ESS_CERT_ID_new_init(X509 *cert, int issuer_needed)
847 {
848 	ESS_CERT_ID *cid = NULL;
849 	GENERAL_NAME *name = NULL;
850 
851 	/* Recompute SHA1 hash of certificate if necessary (side effect). */
852 	X509_check_purpose(cert, -1, 0);
853 
854 	if (!(cid = ESS_CERT_ID_new()))
855 		goto err;
856 	if (!ASN1_OCTET_STRING_set(cid->hash, cert->sha1_hash,
857 	    sizeof(cert->sha1_hash)))
858 		goto err;
859 
860 	/* Setting the issuer/serial if requested. */
861 	if (issuer_needed) {
862 		/* Creating issuer/serial structure. */
863 		if (!cid->issuer_serial &&
864 		    !(cid->issuer_serial = ESS_ISSUER_SERIAL_new()))
865 			goto err;
866 		/* Creating general name from the certificate issuer. */
867 		if (!(name = GENERAL_NAME_new()))
868 			goto err;
869 		name->type = GEN_DIRNAME;
870 		if (!(name->d.dirn = X509_NAME_dup(cert->cert_info->issuer)))
871 			goto err;
872 		if (!sk_GENERAL_NAME_push(cid->issuer_serial->issuer, name))
873 			goto err;
874 		name = NULL;	/* Ownership is lost. */
875 		/* Setting the serial number. */
876 		ASN1_INTEGER_free(cid->issuer_serial->serial);
877 		if (!(cid->issuer_serial->serial =
878 		    ASN1_INTEGER_dup(cert->cert_info->serialNumber)))
879 			goto err;
880 	}
881 
882 	return cid;
883 
884 err:
885 	GENERAL_NAME_free(name);
886 	ESS_CERT_ID_free(cid);
887 	TSerror(ERR_R_MALLOC_FAILURE);
888 	return NULL;
889 }
890 
891 static int
892 TS_TST_INFO_content_new(PKCS7 *p7)
893 {
894 	PKCS7 *ret = NULL;
895 	ASN1_OCTET_STRING *octet_string = NULL;
896 
897 	/* Create new encapsulated NID_id_smime_ct_TSTInfo content. */
898 	if (!(ret = PKCS7_new()))
899 		goto err;
900 	if (!(ret->d.other = ASN1_TYPE_new()))
901 		goto err;
902 	ret->type = OBJ_nid2obj(NID_id_smime_ct_TSTInfo);
903 	if (!(octet_string = ASN1_OCTET_STRING_new()))
904 		goto err;
905 	ASN1_TYPE_set(ret->d.other, V_ASN1_OCTET_STRING, octet_string);
906 	octet_string = NULL;
907 
908 	/* Add encapsulated content to signed PKCS7 structure. */
909 	if (!PKCS7_set_content(p7, ret))
910 		goto err;
911 
912 	return 1;
913 
914 err:
915 	ASN1_OCTET_STRING_free(octet_string);
916 	PKCS7_free(ret);
917 	return 0;
918 }
919 
920 static int
921 ESS_add_signing_cert(PKCS7_SIGNER_INFO *si, ESS_SIGNING_CERT *sc)
922 {
923 	ASN1_STRING *seq = NULL;
924 	unsigned char *p, *pp = NULL;
925 	int len;
926 
927 	len = i2d_ESS_SIGNING_CERT(sc, NULL);
928 	if (!(pp = malloc(len))) {
929 		TSerror(ERR_R_MALLOC_FAILURE);
930 		goto err;
931 	}
932 	p = pp;
933 	i2d_ESS_SIGNING_CERT(sc, &p);
934 	if (!(seq = ASN1_STRING_new()) || !ASN1_STRING_set(seq, pp, len)) {
935 		TSerror(ERR_R_MALLOC_FAILURE);
936 		goto err;
937 	}
938 	free(pp);
939 	pp = NULL;
940 	return PKCS7_add_signed_attribute(si,
941 	    NID_id_smime_aa_signingCertificate, V_ASN1_SEQUENCE, seq);
942 
943 err:
944 	ASN1_STRING_free(seq);
945 	free(pp);
946 
947 	return 0;
948 }
949 
950 
951 static ASN1_GENERALIZEDTIME *
952 TS_RESP_set_genTime_with_precision(ASN1_GENERALIZEDTIME *asn1_time,
953     time_t sec, long usec, unsigned precision)
954 {
955 	struct tm *tm = NULL;
956 	char genTime_str[17 + TS_MAX_CLOCK_PRECISION_DIGITS];
957 	char usecstr[TS_MAX_CLOCK_PRECISION_DIGITS + 2];
958 	char *p;
959 	int rv;
960 
961 	if (precision > TS_MAX_CLOCK_PRECISION_DIGITS)
962 		goto err;
963 
964 	if (!(tm = gmtime(&sec)))
965 		goto err;
966 
967 	/*
968 	 * Put "genTime_str" in GeneralizedTime format.  We work around the
969 	 * restrictions imposed by rfc3280 (i.e. "GeneralizedTime values MUST
970 	 * NOT include fractional seconds") and OpenSSL related functions to
971 	 * meet the rfc3161 requirement: "GeneralizedTime syntax can include
972 	 * fraction-of-second details".
973 	 */
974 	if (precision > 0) {
975 		/* To make things a bit harder, X.690 | ISO/IEC 8825-1 provides
976 		   the following restrictions for a DER-encoding, which OpenSSL
977 		   (specifically ASN1_GENERALIZEDTIME_check() function) doesn't
978 		   support:
979 		   "The encoding MUST terminate with a "Z" (which means "Zulu"
980 		   time). The decimal point element, if present, MUST be the
981 		   point option ".". The fractional-seconds elements,
982 		   if present, MUST omit all trailing 0's;
983 		   if the elements correspond to 0, they MUST be wholly
984 		   omitted, and the decimal point element also MUST be
985 		   omitted." */
986 		(void) snprintf(usecstr, sizeof(usecstr), ".%06ld", usec);
987 		/* truncate and trim trailing 0 */
988 		usecstr[precision + 1] = '\0';
989 		p = usecstr + strlen(usecstr) - 1;
990 		while (p > usecstr && *p == '0')
991 			*p-- = '\0';
992 		/* if we've reached the beginning, delete the . too */
993 		if (p == usecstr)
994 			*p = '\0';
995 
996 	} else {
997 		/* empty */
998 		usecstr[0] = '\0';
999 	}
1000 	rv = snprintf(genTime_str, sizeof(genTime_str),
1001 	    "%04d%02d%02d%02d%02d%02d%sZ",
1002 	    tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
1003 	    tm->tm_hour, tm->tm_min, tm->tm_sec, usecstr);
1004 	if (rv < 0 || rv >= sizeof(genTime_str))
1005 		goto err;
1006 
1007 	/* Now call OpenSSL to check and set our genTime value */
1008 	if (!asn1_time && !(asn1_time = ASN1_GENERALIZEDTIME_new()))
1009 		goto err;
1010 	if (!ASN1_GENERALIZEDTIME_set_string(asn1_time, genTime_str)) {
1011 		ASN1_GENERALIZEDTIME_free(asn1_time);
1012 		goto err;
1013 	}
1014 
1015 	return asn1_time;
1016 
1017 err:
1018 	TSerror(TS_R_COULD_NOT_SET_TIME);
1019 	return NULL;
1020 }
1021