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[strongswan.git] / src / libstrongswan / crypto / ocsp.c
1 /**
2 * @file ocsp.c
3 *
4 * @brief Implementation of ocsp_t.
5 *
6 */
7
8 /* Support of the Online Certificate Status Protocol (OCSP)
9 * Copyright (C) 2003 Christoph Gysin, Simon Zwahlen
10 * Zuercher Hochschule Winterthur
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the
14 * Free Software Foundation; either version 2 of the License, or (at your
15 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
16 *
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
19 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
20 * for more details.
21 *
22 */
23
24 #include <unistd.h>
25 #include <stdlib.h>
26 #include <stdio.h>
27 #include <string.h>
28 #include <time.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <fcntl.h>
32
33 #include <asn1/oid.h>
34 #include <asn1/asn1.h>
35 #include <utils/identification.h>
36 #include <utils/randomizer.h>
37 #include <utils/fetcher.h>
38 #include <debug.h>
39
40 #include "hashers/hasher.h"
41 #include "rsa/rsa_public_key.h"
42 #include "certinfo.h"
43 #include "x509.h"
44 #include "ocsp.h"
45
46 #define NONCE_LENGTH 16
47
48 typedef struct private_ocsp_t private_ocsp_t;
49
50 /**
51 * Private data of a ocsp_t object.
52 */
53 struct private_ocsp_t {
54 /**
55 * Public interface for this ocsp object.
56 */
57 ocsp_t public;
58
59 /**
60 * CA certificate.
61 */
62 x509_t *cacert;
63
64 /**
65 * Requestor certificate
66 */
67 x509_t *requestor_cert;
68
69 /**
70 * Linked list of ocsp uris
71 */
72 linked_list_t *uris;
73
74 /**
75 * Linked list of certinfos to be requested
76 */
77 linked_list_t *certinfos;
78
79 /**
80 * Nonce required for ocsp request and response
81 */
82 chunk_t nonce;
83
84 /**
85 * SHA-1 hash over issuer distinguished name
86 */
87 chunk_t authNameID;
88
89 /**
90 * SHA-1 hash over issuer public key
91 */
92 chunk_t authKeyID;
93 };
94
95 ENUM(response_status_names, STATUS_SUCCESSFUL, STATUS_UNAUTHORIZED,
96 "successful",
97 "malformed request",
98 "internal error",
99 "try later",
100 "signature required",
101 "unauthorized"
102 );
103
104 /* response container */
105 typedef struct response_t response_t;
106
107 struct response_t {
108 chunk_t chunk;
109 chunk_t tbs;
110 identification_t *responder_id_name;
111 chunk_t responder_id_key;
112 time_t produced_at;
113 chunk_t responses;
114 chunk_t nonce;
115 int algorithm;
116 chunk_t signature;
117 x509_t *responder_cert;
118
119 /**
120 * @brief Destroys the response_t object
121 *
122 * @param this response_t to destroy
123 */
124 void (*destroy) (response_t *this);
125 };
126
127 /**
128 * Implements response_t.destroy.
129 */
130 static void response_destroy(response_t *this)
131 {
132 DESTROY_IF(this->responder_id_name);
133 DESTROY_IF(this->responder_cert);
134 free(this->chunk.ptr);
135 free(this);
136 }
137
138 /**
139 * Creates a response_t object
140 */
141 static response_t* response_create_from_chunk(chunk_t chunk)
142 {
143 response_t *this = malloc_thing(response_t);
144
145 this->chunk = chunk;
146 this->tbs = chunk_empty;
147 this->responder_id_name = NULL;
148 this->responder_id_key = chunk_empty;
149 this->produced_at = UNDEFINED_TIME;
150 this->responses = chunk_empty;
151 this->nonce = chunk_empty;
152 this->algorithm = OID_UNKNOWN;
153 this->signature = chunk_empty;
154 this->responder_cert = NULL;
155
156 this->destroy = (void (*) (response_t*))response_destroy;
157
158 return this;
159 }
160
161 /* some OCSP specific prefabricated ASN.1 constants */
162
163 static u_char ASN1_nonce_oid_str[] = {
164 0x06, 0x09,
165 0x2B, 0x06,
166 0x01, 0x05, 0x05, 0x07, 0x30, 0x01, 0x02
167 };
168
169 static u_char ASN1_response_oid_str[] = {
170 0x06, 0x09,
171 0x2B, 0x06,
172 0x01, 0x05, 0x05, 0x07, 0x30, 0x01, 0x04
173 };
174
175 static u_char ASN1_response_content_str[] = {
176 0x04, 0x0D,
177 0x30, 0x0B,
178 0x06, 0x09,
179 0x2B, 0x06,
180 0x01, 0x05, 0x05, 0x07, 0x30, 0x01, 0x01
181 };
182
183 static const chunk_t ASN1_nonce_oid = chunk_from_buf(ASN1_nonce_oid_str);
184 static const chunk_t ASN1_response_oid = chunk_from_buf(ASN1_response_oid_str);
185 static const chunk_t ASN1_response_content = chunk_from_buf(ASN1_response_content_str);
186
187 /* asn.1 definitions for parsing */
188
189 static const asn1Object_t ocspResponseObjects[] = {
190 { 0, "OCSPResponse", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */
191 { 1, "responseStatus", ASN1_ENUMERATED, ASN1_BODY }, /* 1 */
192 { 1, "responseBytesContext", ASN1_CONTEXT_C_0, ASN1_OPT }, /* 2 */
193 { 2, "responseBytes", ASN1_SEQUENCE, ASN1_NONE }, /* 3 */
194 { 3, "responseType", ASN1_OID, ASN1_BODY }, /* 4 */
195 { 3, "response", ASN1_OCTET_STRING, ASN1_BODY }, /* 5 */
196 { 1, "end opt", ASN1_EOC, ASN1_END } /* 6 */
197 };
198
199 #define OCSP_RESPONSE_STATUS 1
200 #define OCSP_RESPONSE_TYPE 4
201 #define OCSP_RESPONSE 5
202 #define OCSP_RESPONSE_ROOF 7
203
204 static const asn1Object_t basicResponseObjects[] = {
205 { 0, "BasicOCSPResponse", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */
206 { 1, "tbsResponseData", ASN1_SEQUENCE, ASN1_OBJ }, /* 1 */
207 { 2, "versionContext", ASN1_CONTEXT_C_0, ASN1_NONE |
208 ASN1_DEF }, /* 2 */
209 { 3, "version", ASN1_INTEGER, ASN1_BODY }, /* 3 */
210 { 2, "responderIdContext", ASN1_CONTEXT_C_1, ASN1_OPT }, /* 4 */
211 { 3, "responderIdByName", ASN1_SEQUENCE, ASN1_OBJ }, /* 5 */
212 { 2, "end choice", ASN1_EOC, ASN1_END }, /* 6 */
213 { 2, "responderIdContext", ASN1_CONTEXT_C_2, ASN1_OPT }, /* 7 */
214 { 3, "responderIdByKey", ASN1_OCTET_STRING, ASN1_BODY }, /* 8 */
215 { 2, "end choice", ASN1_EOC, ASN1_END }, /* 9 */
216 { 2, "producedAt", ASN1_GENERALIZEDTIME, ASN1_BODY }, /* 10 */
217 { 2, "responses", ASN1_SEQUENCE, ASN1_OBJ }, /* 11 */
218 { 2, "responseExtensionsContext", ASN1_CONTEXT_C_1, ASN1_OPT }, /* 12 */
219 { 3, "responseExtensions", ASN1_SEQUENCE, ASN1_LOOP }, /* 13 */
220 { 4, "extension", ASN1_SEQUENCE, ASN1_NONE }, /* 14 */
221 { 5, "extnID", ASN1_OID, ASN1_BODY }, /* 15 */
222 { 5, "critical", ASN1_BOOLEAN, ASN1_BODY |
223 ASN1_DEF }, /* 16 */
224 { 5, "extnValue", ASN1_OCTET_STRING, ASN1_BODY }, /* 17 */
225 { 4, "end loop", ASN1_EOC, ASN1_END }, /* 18 */
226 { 2, "end opt", ASN1_EOC, ASN1_END }, /* 19 */
227 { 1, "signatureAlgorithm", ASN1_EOC, ASN1_RAW }, /* 20 */
228 { 1, "signature", ASN1_BIT_STRING, ASN1_BODY }, /* 21 */
229 { 1, "certsContext", ASN1_CONTEXT_C_0, ASN1_OPT }, /* 22 */
230 { 2, "certs", ASN1_SEQUENCE, ASN1_LOOP }, /* 23 */
231 { 3, "certificate", ASN1_SEQUENCE, ASN1_RAW }, /* 24 */
232 { 2, "end loop", ASN1_EOC, ASN1_END }, /* 25 */
233 { 1, "end opt", ASN1_EOC, ASN1_END } /* 26 */
234 };
235
236 #define BASIC_RESPONSE_TBS_DATA 1
237 #define BASIC_RESPONSE_VERSION 3
238 #define BASIC_RESPONSE_ID_BY_NAME 5
239 #define BASIC_RESPONSE_ID_BY_KEY 8
240 #define BASIC_RESPONSE_PRODUCED_AT 10
241 #define BASIC_RESPONSE_RESPONSES 11
242 #define BASIC_RESPONSE_EXT_ID 15
243 #define BASIC_RESPONSE_CRITICAL 16
244 #define BASIC_RESPONSE_EXT_VALUE 17
245 #define BASIC_RESPONSE_ALGORITHM 20
246 #define BASIC_RESPONSE_SIGNATURE 21
247 #define BASIC_RESPONSE_CERTIFICATE 24
248 #define BASIC_RESPONSE_ROOF 27
249
250 static const asn1Object_t responsesObjects[] = {
251 { 0, "responses", ASN1_SEQUENCE, ASN1_LOOP }, /* 0 */
252 { 1, "singleResponse", ASN1_EOC, ASN1_RAW }, /* 1 */
253 { 0, "end loop", ASN1_EOC, ASN1_END } /* 2 */
254 };
255
256 #define RESPONSES_SINGLE_RESPONSE 1
257 #define RESPONSES_ROOF 3
258
259 static const asn1Object_t singleResponseObjects[] = {
260 { 0, "singleResponse", ASN1_SEQUENCE, ASN1_BODY }, /* 0 */
261 { 1, "certID", ASN1_SEQUENCE, ASN1_NONE }, /* 1 */
262 { 2, "algorithm", ASN1_EOC, ASN1_RAW }, /* 2 */
263 { 2, "issuerNameHash", ASN1_OCTET_STRING, ASN1_BODY }, /* 3 */
264 { 2, "issuerKeyHash", ASN1_OCTET_STRING, ASN1_BODY }, /* 4 */
265 { 2, "serialNumber", ASN1_INTEGER, ASN1_BODY }, /* 5 */
266 { 1, "certStatusGood", ASN1_CONTEXT_S_0, ASN1_OPT }, /* 6 */
267 { 1, "end opt", ASN1_EOC, ASN1_END }, /* 7 */
268 { 1, "certStatusRevoked", ASN1_CONTEXT_C_1, ASN1_OPT }, /* 8 */
269 { 2, "revocationTime", ASN1_GENERALIZEDTIME, ASN1_BODY }, /* 9 */
270 { 2, "revocationReason", ASN1_CONTEXT_C_0, ASN1_OPT }, /* 10 */
271 { 3, "crlReason", ASN1_ENUMERATED, ASN1_BODY }, /* 11 */
272 { 2, "end opt", ASN1_EOC, ASN1_END }, /* 12 */
273 { 1, "end opt", ASN1_EOC, ASN1_END }, /* 13 */
274 { 1, "certStatusUnknown", ASN1_CONTEXT_S_2, ASN1_OPT }, /* 14 */
275 { 1, "end opt", ASN1_EOC, ASN1_END }, /* 15 */
276 { 1, "thisUpdate", ASN1_GENERALIZEDTIME, ASN1_BODY }, /* 16 */
277 { 1, "nextUpdateContext", ASN1_CONTEXT_C_0, ASN1_OPT }, /* 17 */
278 { 2, "nextUpdate", ASN1_GENERALIZEDTIME, ASN1_BODY }, /* 18 */
279 { 1, "end opt", ASN1_EOC, ASN1_END }, /* 19 */
280 { 1, "singleExtensionsContext", ASN1_CONTEXT_C_1, ASN1_OPT }, /* 20 */
281 { 2, "singleExtensions", ASN1_SEQUENCE, ASN1_LOOP }, /* 21 */
282 { 3, "extension", ASN1_SEQUENCE, ASN1_NONE }, /* 22 */
283 { 4, "extnID", ASN1_OID, ASN1_BODY }, /* 23 */
284 { 4, "critical", ASN1_BOOLEAN, ASN1_BODY |
285 ASN1_DEF }, /* 24 */
286 { 4, "extnValue", ASN1_OCTET_STRING, ASN1_BODY }, /* 25 */
287 { 2, "end loop", ASN1_EOC, ASN1_END }, /* 26 */
288 { 1, "end opt", ASN1_EOC, ASN1_END } /* 27 */
289 };
290
291 #define SINGLE_RESPONSE_ALGORITHM 2
292 #define SINGLE_RESPONSE_ISSUER_NAME_HASH 3
293 #define SINGLE_RESPONSE_ISSUER_KEY_HASH 4
294 #define SINGLE_RESPONSE_SERIAL_NUMBER 5
295 #define SINGLE_RESPONSE_CERT_STATUS_GOOD 6
296 #define SINGLE_RESPONSE_CERT_STATUS_REVOKED 8
297 #define SINGLE_RESPONSE_CERT_STATUS_REVOCATION_TIME 9
298 #define SINGLE_RESPONSE_CERT_STATUS_CRL_REASON 11
299 #define SINGLE_RESPONSE_CERT_STATUS_UNKNOWN 14
300 #define SINGLE_RESPONSE_THIS_UPDATE 16
301 #define SINGLE_RESPONSE_NEXT_UPDATE 18
302 #define SINGLE_RESPONSE_EXT_ID 23
303 #define SINGLE_RESPONSE_CRITICAL 24
304 #define SINGLE_RESPONSE_EXT_VALUE 25
305 #define SINGLE_RESPONSE_ROOF 28
306
307 /**
308 * build requestorName (into TBSRequest)
309 */
310 static chunk_t build_requestor_name(private_ocsp_t *this)
311 {
312 identification_t *requestor_name = this->requestor_cert->get_subject(this->requestor_cert);
313
314 return asn1_wrap(ASN1_CONTEXT_C_1, "m",
315 asn1_simple_object(ASN1_CONTEXT_C_4,
316 requestor_name->get_encoding(requestor_name)));
317 }
318
319 /**
320 * build request (into requestList)
321 * no singleRequestExtensions used
322 */
323 static chunk_t build_request(private_ocsp_t *this, certinfo_t *certinfo)
324 {
325 chunk_t serialNumber = certinfo->get_serialNumber(certinfo);
326
327 chunk_t reqCert = asn1_wrap(ASN1_SEQUENCE, "cmmm",
328 ASN1_sha1_id,
329 asn1_simple_object(ASN1_OCTET_STRING, this->authNameID),
330 asn1_simple_object(ASN1_OCTET_STRING, this->authKeyID),
331 asn1_simple_object(ASN1_INTEGER, serialNumber));
332
333 return asn1_wrap(ASN1_SEQUENCE, "m", reqCert);
334 }
335
336 /**
337 * build requestList (into TBSRequest)
338 */
339 static chunk_t build_request_list(private_ocsp_t *this)
340 {
341 chunk_t requestList;
342 size_t datalen = 0;
343 linked_list_t *request_list = linked_list_create();
344
345 {
346 iterator_t *iterator = this->certinfos->create_iterator(this->certinfos, TRUE);
347 certinfo_t *certinfo;
348
349 while (iterator->iterate(iterator, (void**)&certinfo))
350 {
351 chunk_t *request = malloc_thing(chunk_t);
352
353 *request = build_request(this, certinfo);
354 request_list->insert_last(request_list, (void*)request);
355 datalen += request->len;
356 }
357 iterator->destroy(iterator);
358 }
359 {
360 iterator_t *iterator = request_list->create_iterator(request_list, TRUE);
361 chunk_t *request;
362
363 u_char *pos = build_asn1_object(&requestList, ASN1_SEQUENCE, datalen);
364
365 while (iterator->iterate(iterator, (void**)&request))
366 {
367 memcpy(pos, request->ptr, request->len);
368 pos += request->len;
369 free(request->ptr);
370 free(request);
371 }
372 iterator->destroy(iterator);
373 request_list->destroy(request_list);
374 }
375 return requestList;
376 }
377
378 /**
379 * build nonce extension (into requestExtensions)
380 */
381 static chunk_t build_nonce_extension(private_ocsp_t *this)
382 {
383 randomizer_t *randomizer = randomizer_create();
384
385 /* generate a random nonce */
386 randomizer->allocate_pseudo_random_bytes(randomizer, NONCE_LENGTH, &this->nonce);
387 randomizer->destroy(randomizer);
388
389 return asn1_wrap(ASN1_SEQUENCE, "cm",
390 ASN1_nonce_oid,
391 asn1_simple_object(ASN1_OCTET_STRING, this->nonce));
392 }
393
394 /**
395 * build requestExtensions (into TBSRequest)
396 */
397 static chunk_t build_request_ext(private_ocsp_t *this)
398 {
399 return asn1_wrap(ASN1_CONTEXT_C_2, "m",
400 asn1_wrap(ASN1_SEQUENCE, "mm",
401 build_nonce_extension(this),
402 asn1_wrap(ASN1_SEQUENCE, "cc",
403 ASN1_response_oid,
404 ASN1_response_content
405 )
406 )
407 );
408 }
409
410 /**
411 * build TBSRequest (into OCSPRequest)
412 */
413 static chunk_t build_tbs_request(private_ocsp_t *this, bool has_requestor_cert)
414 {
415 /* version is skipped since the default is ok */
416 return asn1_wrap(ASN1_SEQUENCE, "mmm",
417 (has_requestor_cert)? build_requestor_name(this): chunk_empty,
418 build_request_list(this),
419 build_request_ext(this));
420 }
421
422 /**
423 * build signature into ocsp request
424 * gets built only if a request cert with a corresponding private key is found
425 */
426 static chunk_t build_signature(private_ocsp_t *this, chunk_t tbsRequest)
427 {
428 /* TODO */
429 return chunk_empty;
430 }
431
432 /**
433 * assembles an ocsp request and sets the nonce field in private_ocsp_t to the sent nonce
434 */
435 static chunk_t ocsp_build_request(private_ocsp_t *this)
436 {
437 bool has_requestor_cert;
438 chunk_t keyid = this->cacert->get_keyid(this->cacert);
439 chunk_t tbsRequest, signature;
440
441 DBG2("assembling ocsp request");
442 DBG2("issuer: '%D'", this->cacert->get_subject(this->cacert));
443 DBG2("keyid: %#B", &keyid);
444
445 /* looks for requestor cert and matching private key */
446 has_requestor_cert = FALSE;
447
448 /* TODO has_requestor_cert = get_ocsp_requestor_cert(location); */
449
450 /* build content */
451 tbsRequest = build_tbs_request(this, has_requestor_cert);
452
453 /* sign tbsReuqest */
454 signature = (has_requestor_cert)? build_signature(this, tbsRequest): chunk_empty;
455
456 return asn1_wrap(ASN1_SEQUENCE, "mm",
457 tbsRequest,
458 signature);
459
460 return signature;
461 }
462
463 /**
464 * parse a basic OCSP response
465 */
466 static bool ocsp_parse_basic_response(chunk_t blob, int level0, response_t *res)
467 {
468 u_int level, version;
469 u_int extn_oid = OID_UNKNOWN;
470 asn1_ctx_t ctx;
471 bool critical;
472 chunk_t object;
473 int objectID = 0;
474
475 asn1_init(&ctx, blob, level0, FALSE, FALSE);
476
477 while (objectID < BASIC_RESPONSE_ROOF)
478 {
479 if (!extract_object(basicResponseObjects, &objectID, &object, &level, &ctx))
480 {
481 return FALSE;
482 }
483
484 switch (objectID)
485 {
486 case BASIC_RESPONSE_TBS_DATA:
487 res->tbs = object;
488 break;
489 case BASIC_RESPONSE_VERSION:
490 version = (object.len)? (1 + (u_int)*object.ptr) : 1;
491 if (version != OCSP_BASIC_RESPONSE_VERSION)
492 {
493 DBG1("wrong ocsp basic response version (version= %i)", version);
494 return FALSE;
495 }
496 break;
497 case BASIC_RESPONSE_ID_BY_NAME:
498 res->responder_id_name = identification_create_from_encoding(ID_DER_ASN1_DN, object);
499 DBG2(" '%D'", res->responder_id_name);
500 break;
501 case BASIC_RESPONSE_ID_BY_KEY:
502 res->responder_id_key = object;
503 break;
504 case BASIC_RESPONSE_PRODUCED_AT:
505 res->produced_at = asn1totime(&object, ASN1_GENERALIZEDTIME);
506 break;
507 case BASIC_RESPONSE_RESPONSES:
508 res->responses = object;
509 break;
510 case BASIC_RESPONSE_EXT_ID:
511 extn_oid = known_oid(object);
512 break;
513 case BASIC_RESPONSE_CRITICAL:
514 critical = object.len && *object.ptr;
515 DBG2(" %s", critical? "TRUE" : "FALSE");
516 break;
517 case BASIC_RESPONSE_EXT_VALUE:
518 if (extn_oid == OID_NONCE)
519 res->nonce = object;
520 break;
521 case BASIC_RESPONSE_ALGORITHM:
522 res->algorithm = parse_algorithmIdentifier(object, level+1, NULL);
523 break;
524 case BASIC_RESPONSE_SIGNATURE:
525 res->signature = object;
526 break;
527 case BASIC_RESPONSE_CERTIFICATE:
528 {
529 chunk_t blob = chunk_clone(object);
530
531 res->responder_cert = x509_create_from_chunk(blob, level+1);
532 }
533 break;
534 }
535 objectID++;
536 }
537 return TRUE;
538 }
539
540 /**
541 * parse an ocsp response and return the result as a response_t struct
542 */
543 static response_status ocsp_parse_response(response_t *res)
544 {
545 asn1_ctx_t ctx;
546 chunk_t object;
547 u_int level;
548 int objectID = 0;
549
550 response_status rStatus = STATUS_INTERNALERROR;
551 u_int ocspResponseType = OID_UNKNOWN;
552
553 asn1_init(&ctx, res->chunk, 0, FALSE, FALSE);
554
555 while (objectID < OCSP_RESPONSE_ROOF)
556 {
557 if (!extract_object(ocspResponseObjects, &objectID, &object, &level, &ctx))
558 {
559 return STATUS_INTERNALERROR;
560 }
561
562 switch (objectID)
563 {
564 case OCSP_RESPONSE_STATUS:
565 rStatus = (response_status) *object.ptr;
566 DBG2(" '%N'", response_status_names, rStatus);
567
568 switch (rStatus)
569 {
570 case STATUS_SUCCESSFUL:
571 break;
572 case STATUS_MALFORMEDREQUEST:
573 case STATUS_INTERNALERROR:
574 case STATUS_TRYLATER:
575 case STATUS_SIGREQUIRED:
576 case STATUS_UNAUTHORIZED:
577 DBG1("unsuccessful ocsp response: server said '%N'",
578 response_status_names, rStatus);
579 return rStatus;
580 default:
581 return STATUS_INTERNALERROR;
582 }
583 break;
584 case OCSP_RESPONSE_TYPE:
585 ocspResponseType = known_oid(object);
586 break;
587 case OCSP_RESPONSE:
588 {
589 switch (ocspResponseType)
590 {
591 case OID_BASIC:
592 if (!ocsp_parse_basic_response(object, level+1, res))
593 {
594 return STATUS_INTERNALERROR;
595 }
596 break;
597 default:
598 DBG1("ocsp response is not of type BASIC");
599 DBG1("ocsp response OID: %#B", &object);
600 return STATUS_INTERNALERROR;
601 }
602 }
603 break;
604 }
605 objectID++;
606 }
607 return rStatus;
608 }
609
610 /**
611 * Check if the OCSP response has a valid signature
612 */
613 static bool ocsp_valid_response(response_t *res, x509_t *ocsp_cert)
614 {
615 rsa_public_key_t *public_key;
616 time_t until = UNDEFINED_TIME;
617 err_t ugh;
618
619 DBG2("verifying ocsp response signature:");
620 DBG2("signer: '%D'", ocsp_cert->get_subject(ocsp_cert));
621 DBG2("issuer: '%D'", ocsp_cert->get_issuer(ocsp_cert));
622
623 ugh = ocsp_cert->is_valid(ocsp_cert, &until);
624 if (ugh != NULL)
625 {
626 DBG1("ocsp signer certificate %s", ugh);
627 return FALSE;
628 }
629 public_key = ocsp_cert->get_public_key(ocsp_cert);
630
631 return public_key->verify_emsa_pkcs1_signature(public_key, res->tbs, res->signature) == SUCCESS;
632 }
633
634 /**
635 * parse a single OCSP response
636 */
637 static bool ocsp_parse_single_response(private_ocsp_t *this, chunk_t blob, int level0)
638 {
639 u_int level, extn_oid;
640 asn1_ctx_t ctx;
641 bool critical;
642 chunk_t object;
643 int objectID = 0;
644
645 certinfo_t *certinfo = NULL;
646
647 asn1_init(&ctx, blob, level0, FALSE, FALSE);
648
649 while (objectID < SINGLE_RESPONSE_ROOF)
650 {
651 if (!extract_object(singleResponseObjects, &objectID, &object, &level, &ctx))
652 {
653 return FALSE;
654 }
655
656 switch (objectID)
657 {
658 case SINGLE_RESPONSE_ALGORITHM:
659 if (parse_algorithmIdentifier(object, level+1, NULL) != OID_SHA1)
660 {
661 DBG1("only sha-1 hash supported in ocsp single response");
662 return FALSE;
663 }
664 break;
665 case SINGLE_RESPONSE_ISSUER_NAME_HASH:
666 if (!chunk_equals(object, this->authNameID))
667 {
668 DBG1("ocsp single response has wrong issuer name hash");
669 return FALSE;
670 }
671 break;
672 case SINGLE_RESPONSE_ISSUER_KEY_HASH:
673 if (!chunk_equals(object, this->authKeyID))
674 {
675 DBG1("ocsp single response has wrong issuer key hash");
676 return FALSE;
677 }
678 break;
679 case SINGLE_RESPONSE_SERIAL_NUMBER:
680 {
681 iterator_t *iterator = this->certinfos->create_iterator(this->certinfos, TRUE);
682 certinfo_t *current_certinfo;
683
684 while (iterator->iterate(iterator, (void**)&current_certinfo))
685 {
686 if (chunk_equals(object, current_certinfo->get_serialNumber(current_certinfo)))
687 {
688 certinfo = current_certinfo;
689 }
690 }
691 iterator->destroy(iterator);
692 if (certinfo == NULL)
693 {
694 DBG1("unrequested serial number in ocsp single response");
695 return FALSE;
696 }
697 }
698 break;
699 case SINGLE_RESPONSE_CERT_STATUS_GOOD:
700 certinfo->set_status(certinfo, CERT_GOOD);
701 break;
702 case SINGLE_RESPONSE_CERT_STATUS_REVOKED:
703 certinfo->set_status(certinfo, CERT_REVOKED);
704 break;
705 case SINGLE_RESPONSE_CERT_STATUS_REVOCATION_TIME:
706 certinfo->set_revocationTime(certinfo,
707 asn1totime(&object, ASN1_GENERALIZEDTIME));
708 break;
709 case SINGLE_RESPONSE_CERT_STATUS_CRL_REASON:
710 certinfo->set_revocationReason(certinfo,
711 (object.len == 1) ? *object.ptr : REASON_UNSPECIFIED);
712 break;
713 case SINGLE_RESPONSE_CERT_STATUS_UNKNOWN:
714 certinfo->set_status(certinfo, CERT_UNKNOWN);
715 break;
716 case SINGLE_RESPONSE_THIS_UPDATE:
717 certinfo->set_thisUpdate(certinfo,
718 asn1totime(&object, ASN1_GENERALIZEDTIME));
719 break;
720 case SINGLE_RESPONSE_NEXT_UPDATE:
721 certinfo->set_nextUpdate(certinfo,
722 asn1totime(&object, ASN1_GENERALIZEDTIME));
723 break;
724 case SINGLE_RESPONSE_EXT_ID:
725 extn_oid = known_oid(object);
726 break;
727 case SINGLE_RESPONSE_CRITICAL:
728 critical = object.len && *object.ptr;
729 DBG2(" %s", critical ? "TRUE" : "FALSE");
730 case SINGLE_RESPONSE_EXT_VALUE:
731 break;
732 }
733 objectID++;
734 }
735 return TRUE;
736 }
737
738 /**
739 * verify and process ocsp response and update the ocsp cache
740 */
741 static void ocsp_process_response(private_ocsp_t *this, response_t *res, credential_store_t *credentials)
742 {
743 x509_t *ocsp_cert = NULL;
744
745 /* parse the ocsp response without looking at the single responses yet */
746 response_status status = ocsp_parse_response(res);
747
748 if (status != STATUS_SUCCESSFUL)
749 {
750 DBG1("error in ocsp response");
751 return;
752 }
753
754 /* check if there was a nonce in the request */
755 if (this->nonce.ptr != NULL && res->nonce.ptr == NULL)
756 {
757 DBG1("ocsp response contains no nonce, replay attack possible");
758 }
759
760 /* check if the nonces are identical */
761 if (res->nonce.ptr != NULL && !chunk_equals(res->nonce, this->nonce))
762 {
763 DBG1("invalid nonce in ocsp response");
764 return;
765 }
766
767 /* check if we received a trusted responder certificate */
768 if (res->responder_cert)
769 {
770 if (res->responder_cert->is_ocsp_signer(res->responder_cert))
771 {
772 DBG2("received certificate is ocsp signer");
773 if (credentials->is_trusted(credentials, res->responder_cert))
774 {
775 DBG1("received ocsp signer certificate is trusted");
776 ocsp_cert = credentials->add_auth_certificate(credentials,
777 res->responder_cert, AUTH_OCSP);
778 res->responder_cert = NULL;
779 }
780 else
781 {
782 DBG1("received ocsp signer certificate is not trusted - rejected");
783 }
784 }
785 else
786 {
787 DBG1("received certificate is no ocsp signer - rejected");
788 }
789 }
790
791 /* if we didn't receive a trusted responder cert, search the credential store */
792 if (ocsp_cert == NULL)
793 {
794 ocsp_cert = credentials->get_auth_certificate(credentials,
795 AUTH_OCSP|AUTH_CA, res->responder_id_name);
796 if (ocsp_cert == NULL)
797 {
798 DBG1("no ocsp signer certificate found");
799 return;
800 }
801 }
802
803 /* check the response signature */
804 if (!ocsp_valid_response(res, ocsp_cert))
805 {
806 DBG1("ocsp response signature is invalid");
807 return;
808 }
809 DBG2("ocsp response signature is valid");
810
811 /* now parse the single responses one at a time */
812 {
813 u_int level;
814 asn1_ctx_t ctx;
815 chunk_t object;
816 int objectID = 0;
817
818 asn1_init(&ctx, res->responses, 0, FALSE, FALSE);
819
820 while (objectID < RESPONSES_ROOF)
821 {
822 if (!extract_object(responsesObjects, &objectID, &object, &level, &ctx))
823 {
824 return;
825 }
826 if (objectID == RESPONSES_SINGLE_RESPONSE)
827 {
828 ocsp_parse_single_response(this, object, level+1);
829 }
830 objectID++;
831 }
832 }
833 }
834
835 /**
836 * Implements ocsp_t.fetch.
837 */
838 static void fetch(private_ocsp_t *this, certinfo_t *certinfo, credential_store_t *credentials)
839 {
840 chunk_t request;
841 response_t *response = NULL;
842
843 if (this->uris->get_count(this->uris) == 0)
844 {
845 return;
846 }
847 this->certinfos->insert_last(this->certinfos, (void*)certinfo);
848
849 request = ocsp_build_request(this);
850 DBG3("ocsp request: %B", &request);
851 {
852 iterator_t *iterator = this->uris->create_iterator(this->uris, TRUE);
853 identification_t *uri;
854
855 while (iterator->iterate(iterator, (void**)&uri))
856 {
857 fetcher_t *fetcher;
858 char uri_string[BUF_LEN];
859 chunk_t uri_chunk = uri->get_encoding(uri);
860 chunk_t response_chunk;
861
862 snprintf(uri_string, BUF_LEN, "%.*s", uri_chunk.len, uri_chunk.ptr);
863 fetcher = fetcher_create(uri_string);
864
865 response_chunk = fetcher->post(fetcher, "application/ocsp-request", request);
866 fetcher->destroy(fetcher);
867 if (response_chunk.ptr != NULL)
868 {
869 response = response_create_from_chunk(response_chunk);
870 break;
871 }
872 }
873 iterator->destroy(iterator);
874 }
875 free(request.ptr);
876
877 if (response == NULL)
878 {
879 return;
880 }
881 DBG3("ocsp response: %B", &response->chunk);
882 ocsp_process_response(this, response, credentials);
883 response->destroy(response);
884 }
885
886 /**
887 * Implements ocsp_t.destroy.
888 */
889 static void destroy(private_ocsp_t *this)
890 {
891 this->certinfos->destroy(this->certinfos);
892 free(this->authNameID.ptr);
893 free(this->nonce.ptr);
894 free(this);
895 }
896
897 /*
898 * Described in header.
899 */
900 ocsp_t *ocsp_create(x509_t *cacert, linked_list_t *uris)
901 {
902 private_ocsp_t *this = malloc_thing(private_ocsp_t);
903
904 /* initialize */
905 this->cacert = cacert;
906 this->uris = uris;
907 this->certinfos = linked_list_create();
908 this->nonce = chunk_empty;
909 this->authKeyID = cacert->get_subjectKeyID(cacert);
910 {
911 hasher_t *hasher = hasher_create(HASH_SHA1);
912 identification_t *issuer = cacert->get_subject(cacert);
913
914 hasher->allocate_hash(hasher, issuer->get_encoding(issuer),
915 &this->authNameID);
916 hasher->destroy(hasher);
917 }
918
919 /* public functions */
920 this->public.fetch = (void (*) (ocsp_t*,certinfo_t*,credential_store_t*))fetch;
921 this->public.destroy = (void (*) (ocsp_t*))destroy;
922
923 return &this->public;
924 }
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