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1 | /* | |
2 | * Copyright 2007-2020 The OpenSSL Project Authors. All Rights Reserved. | |
3 | * Copyright Nokia 2007-2020 | |
4 | * Copyright Siemens AG 2015-2020 | |
5 | * | |
6 | * Licensed under the Apache License 2.0 (the "License"). You may not use | |
7 | * this file except in compliance with the License. You can obtain a copy | |
8 | * in the file LICENSE in the source distribution or at | |
9 | * https://www.openssl.org/source/license.html | |
10 | */ | |
11 | ||
12 | /* CMP functions for PKIMessage checking */ | |
13 | ||
14 | #include "cmp_local.h" | |
15 | #include <openssl/cmp_util.h> | |
16 | ||
17 | /* explicit #includes not strictly needed since implied by the above: */ | |
18 | #include <openssl/asn1t.h> | |
19 | #include <openssl/cmp.h> | |
20 | #include <openssl/crmf.h> | |
21 | #include <openssl/err.h> | |
22 | #include <openssl/x509.h> | |
23 | #include "crypto/x509.h" | |
24 | ||
25 | /* | |
26 | * Verify a message protected by signature according to section 5.1.3.3 | |
27 | * (sha1+RSA/DSA or any other algorithm supported by OpenSSL). | |
28 | * | |
29 | * Returns 1 on successful validation and 0 otherwise. | |
30 | */ | |
31 | static int verify_signature(const OSSL_CMP_CTX *cmp_ctx, | |
32 | const OSSL_CMP_MSG *msg, X509 *cert) | |
33 | { | |
34 | EVP_MD_CTX *ctx = NULL; | |
35 | CMP_PROTECTEDPART prot_part; | |
36 | int digest_nid, pk_nid; | |
37 | const EVP_MD *digest = NULL; | |
38 | EVP_PKEY *pubkey = NULL; | |
39 | int len; | |
40 | size_t prot_part_der_len = 0; | |
41 | unsigned char *prot_part_der = NULL; | |
42 | BIO *bio = BIO_new(BIO_s_mem()); /* may be NULL */ | |
43 | int res = 0; | |
44 | ||
45 | if (!ossl_assert(cmp_ctx != NULL && msg != NULL && cert != NULL)) | |
46 | return 0; | |
47 | ||
48 | /* verify that keyUsage, if present, contains digitalSignature */ | |
49 | if (!cmp_ctx->ignore_keyusage | |
50 | && (X509_get_key_usage(cert) & X509v3_KU_DIGITAL_SIGNATURE) == 0) { | |
51 | CMPerr(0, CMP_R_MISSING_KEY_USAGE_DIGITALSIGNATURE); | |
52 | goto sig_err; | |
53 | } | |
54 | ||
55 | pubkey = X509_get_pubkey(cert); | |
56 | if (pubkey == NULL) { | |
57 | CMPerr(0, CMP_R_FAILED_EXTRACTING_PUBKEY); | |
58 | goto sig_err; | |
59 | } | |
60 | ||
61 | /* create the DER representation of protected part */ | |
62 | prot_part.header = msg->header; | |
63 | prot_part.body = msg->body; | |
64 | ||
65 | len = i2d_CMP_PROTECTEDPART(&prot_part, &prot_part_der); | |
66 | if (len < 0 || prot_part_der == NULL) | |
67 | goto end; | |
68 | prot_part_der_len = (size_t) len; | |
69 | ||
70 | /* verify signature of protected part */ | |
71 | if (!OBJ_find_sigid_algs(OBJ_obj2nid(msg->header->protectionAlg->algorithm), | |
72 | &digest_nid, &pk_nid) | |
73 | || digest_nid == NID_undef || pk_nid == NID_undef | |
74 | || (digest = EVP_get_digestbynid(digest_nid)) == NULL) { | |
75 | CMPerr(0, CMP_R_ALGORITHM_NOT_SUPPORTED); | |
76 | goto sig_err; | |
77 | } | |
78 | ||
79 | /* check msg->header->protectionAlg is consistent with public key type */ | |
80 | if (EVP_PKEY_type(pk_nid) != EVP_PKEY_base_id(pubkey)) { | |
81 | CMPerr(0, CMP_R_WRONG_ALGORITHM_OID); | |
82 | goto sig_err; | |
83 | } | |
84 | if ((ctx = EVP_MD_CTX_new()) == NULL) | |
85 | goto end; | |
86 | if (EVP_DigestVerifyInit(ctx, NULL, digest, NULL, pubkey) | |
87 | && EVP_DigestVerify(ctx, msg->protection->data, | |
88 | msg->protection->length, | |
89 | prot_part_der, prot_part_der_len) == 1) { | |
90 | res = 1; | |
91 | goto end; | |
92 | } | |
93 | ||
94 | sig_err: | |
95 | res = x509_print_ex_brief(bio, cert, X509_FLAG_NO_EXTENSIONS); | |
96 | CMPerr(0, CMP_R_ERROR_VALIDATING_PROTECTION); | |
97 | if (res) | |
98 | ERR_add_error_mem_bio("\n", bio); | |
99 | res = 0; | |
100 | ||
101 | end: | |
102 | EVP_MD_CTX_free(ctx); | |
103 | OPENSSL_free(prot_part_der); | |
104 | EVP_PKEY_free(pubkey); | |
105 | BIO_free(bio); | |
106 | ||
107 | return res; | |
108 | } | |
109 | ||
110 | /* Verify a message protected with PBMAC */ | |
111 | static int verify_PBMAC(const OSSL_CMP_MSG *msg, | |
112 | const ASN1_OCTET_STRING *secret) | |
113 | { | |
114 | ASN1_BIT_STRING *protection = NULL; | |
115 | int valid = 0; | |
116 | ||
117 | /* generate expected protection for the message */ | |
118 | if ((protection = ossl_cmp_calc_protection(msg, secret, NULL)) == NULL) | |
119 | return 0; /* failed to generate protection string! */ | |
120 | ||
121 | valid = msg->protection != NULL && msg->protection->length >= 0 | |
122 | && msg->protection->type == protection->type | |
123 | && msg->protection->length == protection->length | |
124 | && CRYPTO_memcmp(msg->protection->data, protection->data, | |
125 | protection->length) == 0; | |
126 | ASN1_BIT_STRING_free(protection); | |
127 | if (!valid) | |
128 | CMPerr(0, CMP_R_WRONG_PBM_VALUE); | |
129 | ||
130 | return valid; | |
131 | } | |
132 | ||
133 | /* | |
134 | * Attempt to validate certificate and path using any given store with trusted | |
135 | * certs (possibly including CRLs and a cert verification callback function) | |
136 | * and non-trusted intermediate certs from the given ctx. | |
137 | * | |
138 | * Returns 1 on successful validation and 0 otherwise. | |
139 | */ | |
140 | int OSSL_CMP_validate_cert_path(OSSL_CMP_CTX *ctx, X509_STORE *trusted_store, | |
141 | X509 *cert) | |
142 | { | |
143 | int valid = 0; | |
144 | X509_STORE_CTX *csc = NULL; | |
145 | int err; | |
146 | ||
147 | if (ctx == NULL || cert == NULL) { | |
148 | CMPerr(0, CMP_R_NULL_ARGUMENT); | |
149 | return 0; | |
150 | } | |
151 | ||
152 | if (trusted_store == NULL) { | |
153 | CMPerr(0, CMP_R_MISSING_TRUST_STORE); | |
154 | return 0; | |
155 | } | |
156 | ||
157 | if ((csc = X509_STORE_CTX_new()) == NULL | |
158 | || !X509_STORE_CTX_init(csc, trusted_store, | |
159 | cert, ctx->untrusted_certs)) | |
160 | goto err; | |
161 | ||
162 | valid = X509_verify_cert(csc) > 0; | |
163 | ||
164 | /* make sure suitable error is queued even if callback did not do */ | |
165 | err = ERR_peek_last_error(); | |
166 | if (!valid && ERR_GET_REASON(err) != CMP_R_POTENTIALLY_INVALID_CERTIFICATE) | |
167 | CMPerr(0, CMP_R_POTENTIALLY_INVALID_CERTIFICATE); | |
168 | ||
169 | err: | |
170 | /* directly output any fresh errors, needed for check_msg_find_cert() */ | |
171 | OSSL_CMP_CTX_print_errors(ctx); | |
172 | X509_STORE_CTX_free(csc); | |
173 | return valid; | |
174 | } | |
175 | ||
176 | /* Return 0 if expect_name != NULL and there is no matching actual_name */ | |
177 | static int check_name(OSSL_CMP_CTX *ctx, | |
178 | const char *actual_desc, const X509_NAME *actual_name, | |
179 | const char *expect_desc, const X509_NAME *expect_name) | |
180 | { | |
181 | char *str; | |
182 | ||
183 | if (expect_name == NULL) | |
184 | return 1; /* no expectation, thus trivially fulfilled */ | |
185 | ||
186 | /* make sure that a matching name is there */ | |
187 | if (actual_name == NULL) { | |
188 | ossl_cmp_log1(WARN, ctx, "missing %s", actual_desc); | |
189 | return 0; | |
190 | } | |
191 | if (X509_NAME_cmp(actual_name, expect_name) == 0) | |
192 | return 1; | |
193 | ||
194 | if ((str = X509_NAME_oneline(actual_name, NULL, 0)) != NULL) | |
195 | ossl_cmp_log2(INFO, ctx, " actual name in %s = %s", actual_desc, str); | |
196 | OPENSSL_free(str); | |
197 | if ((str = X509_NAME_oneline(expect_name, NULL, 0)) != NULL) | |
198 | ossl_cmp_log2(INFO, ctx, " does not match %s = %s", expect_desc, str); | |
199 | OPENSSL_free(str); | |
200 | return 0; | |
201 | } | |
202 | ||
203 | /* Return 0 if skid != NULL and there is no matching subject key ID in cert */ | |
204 | static int check_kid(OSSL_CMP_CTX *ctx, | |
205 | X509 *cert, const ASN1_OCTET_STRING *skid) | |
206 | { | |
207 | char *actual, *expect; | |
208 | const ASN1_OCTET_STRING *ckid = X509_get0_subject_key_id(cert); | |
209 | ||
210 | if (skid == NULL) | |
211 | return 1; /* no expectation, thus trivially fulfilled */ | |
212 | ||
213 | /* make sure that the expected subject key identifier is there */ | |
214 | if (ckid == NULL) { | |
215 | ossl_cmp_warn(ctx, "missing Subject Key Identifier in certificate"); | |
216 | return 0; | |
217 | } | |
218 | if (ASN1_OCTET_STRING_cmp(ckid, skid) == 0) | |
219 | return 1; | |
220 | ||
221 | if ((actual = OPENSSL_buf2hexstr(ckid->data, ckid->length)) != NULL) | |
222 | ossl_cmp_log1(INFO, ctx, " cert Subject Key Identifier = %s", actual); | |
223 | if ((expect = OPENSSL_buf2hexstr(skid->data, skid->length)) != NULL) | |
224 | ossl_cmp_log1(INFO, ctx, " does not match senderKID = %s", expect); | |
225 | OPENSSL_free(expect); | |
226 | OPENSSL_free(actual); | |
227 | return 0; | |
228 | } | |
229 | ||
230 | static int already_checked(X509 *cert, const STACK_OF(X509) *already_checked) | |
231 | { | |
232 | int i; | |
233 | ||
234 | for (i = sk_X509_num(already_checked /* may be NULL */); i > 0; i--) | |
235 | if (X509_cmp(sk_X509_value(already_checked, i - 1), cert) == 0) | |
236 | return 1; | |
237 | return 0; | |
238 | } | |
239 | ||
240 | /* | |
241 | * Check if the given cert is acceptable as sender cert of the given message. | |
242 | * The subject DN must match, the subject key ID as well if present in the msg, | |
243 | * and the cert must be current (checked if ctx->trusted is not NULL). | |
244 | * Note that cert revocation etc. is checked by OSSL_CMP_validate_cert_path(). | |
245 | * | |
246 | * Returns 0 on error or not acceptable, else 1. | |
247 | */ | |
248 | static int cert_acceptable(OSSL_CMP_CTX *ctx, | |
249 | const char *desc1, const char *desc2, X509 *cert, | |
250 | const STACK_OF(X509) *already_checked1, | |
251 | const STACK_OF(X509) *already_checked2, | |
252 | const OSSL_CMP_MSG *msg) | |
253 | { | |
254 | X509_STORE *ts = ctx->trusted; | |
255 | int self_issued = X509_check_issued(cert, cert) == X509_V_OK; | |
256 | char *str; | |
257 | X509_VERIFY_PARAM *vpm = ts != NULL ? X509_STORE_get0_param(ts) : NULL; | |
258 | int time_cmp; | |
259 | ||
260 | ossl_cmp_log3(INFO, ctx, " considering %s%s %s with..", | |
261 | self_issued ? "self-issued ": "", desc1, desc2); | |
262 | if ((str = X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0)) != NULL) | |
263 | ossl_cmp_log1(INFO, ctx, " subject = %s", str); | |
264 | OPENSSL_free(str); | |
265 | if (!self_issued) { | |
266 | str = X509_NAME_oneline(X509_get_issuer_name(cert), NULL, 0); | |
267 | if (str != NULL) | |
268 | ossl_cmp_log1(INFO, ctx, " issuer = %s", str); | |
269 | OPENSSL_free(str); | |
270 | } | |
271 | ||
272 | if (already_checked(cert, already_checked1) | |
273 | || already_checked(cert, already_checked2)) { | |
274 | ossl_cmp_info(ctx, " cert has already been checked"); | |
275 | return 0; | |
276 | } | |
277 | ||
278 | time_cmp = X509_cmp_timeframe(vpm, X509_get0_notBefore(cert), | |
279 | X509_get0_notAfter(cert)); | |
280 | if (time_cmp != 0) { | |
281 | ossl_cmp_warn(ctx, time_cmp > 0 ? "cert has expired" | |
282 | : "cert is not yet valid"); | |
283 | return 0; | |
284 | } | |
285 | ||
286 | if (!check_name(ctx, | |
287 | "cert subject", X509_get_subject_name(cert), | |
288 | "sender field", msg->header->sender->d.directoryName)) | |
289 | return 0; | |
290 | ||
291 | if (!check_kid(ctx, cert, msg->header->senderKID)) | |
292 | return 0; | |
293 | /* acceptable also if there is no senderKID in msg header */ | |
294 | ossl_cmp_info(ctx, " cert seems acceptable"); | |
295 | return 1; | |
296 | } | |
297 | ||
298 | static int check_msg_valid_cert(OSSL_CMP_CTX *ctx, X509_STORE *store, | |
299 | X509 *scrt, const OSSL_CMP_MSG *msg) | |
300 | { | |
301 | if (!verify_signature(ctx, msg, scrt)) { | |
302 | ossl_cmp_warn(ctx, "msg signature verification failed"); | |
303 | return 0; | |
304 | } | |
305 | if (OSSL_CMP_validate_cert_path(ctx, store, scrt)) | |
306 | return 1; | |
307 | ||
308 | ossl_cmp_warn(ctx, | |
309 | "msg signature validates but cert path validation failed"); | |
310 | return 0; | |
311 | } | |
312 | ||
313 | /* | |
314 | * Exceptional handling for 3GPP TS 33.310 [3G/LTE Network Domain Security | |
315 | * (NDS); Authentication Framework (AF)], only to use for IP messages | |
316 | * and if the ctx option is explicitly set: use self-issued certificates | |
317 | * from extraCerts as trust anchor to validate sender cert and msg - | |
318 | * provided it also can validate the newly enrolled certificate | |
319 | */ | |
320 | static int check_msg_valid_cert_3gpp(OSSL_CMP_CTX *ctx, X509 *scrt, | |
321 | const OSSL_CMP_MSG *msg) | |
322 | { | |
323 | int valid = 0; | |
324 | X509_STORE *store; | |
325 | ||
326 | if (!ctx->permitTAInExtraCertsForIR) | |
327 | return 0; | |
328 | ||
329 | if ((store = X509_STORE_new()) == NULL | |
330 | || !ossl_cmp_X509_STORE_add1_certs(store, msg->extraCerts, | |
331 | 1 /* self-issued only */)) | |
332 | goto err; | |
333 | ||
334 | /* store does not include CRLs */ | |
335 | valid = OSSL_CMP_validate_cert_path(ctx, store, scrt); | |
336 | if (!valid) { | |
337 | ossl_cmp_warn(ctx, | |
338 | "also exceptional 3GPP mode cert path validation failed"); | |
339 | } else { | |
340 | /* | |
341 | * verify that the newly enrolled certificate (which assumed rid == | |
342 | * OSSL_CMP_CERTREQID) can also be validated with the same trusted store | |
343 | */ | |
344 | EVP_PKEY *privkey = OSSL_CMP_CTX_get0_newPkey(ctx, 1); | |
345 | OSSL_CMP_CERTRESPONSE *crep = | |
346 | ossl_cmp_certrepmessage_get0_certresponse(msg->body->value.ip, | |
347 | OSSL_CMP_CERTREQID); | |
348 | X509 *newcrt = ossl_cmp_certresponse_get1_certificate(privkey, crep); | |
349 | /* | |
350 | * maybe better use get_cert_status() from cmp_client.c, which catches | |
351 | * errors | |
352 | */ | |
353 | valid = OSSL_CMP_validate_cert_path(ctx, store, newcrt); | |
354 | X509_free(newcrt); | |
355 | } | |
356 | ||
357 | err: | |
358 | X509_STORE_free(store); | |
359 | return valid; | |
360 | } | |
361 | ||
362 | /* | |
363 | * Try all certs in given list for verifying msg, normally or in 3GPP mode. | |
364 | * If already_checked1 == NULL then certs are assumed to be the msg->extraCerts. | |
365 | */ | |
366 | static int check_msg_with_certs(OSSL_CMP_CTX *ctx, STACK_OF(X509) *certs, | |
367 | const char *desc, | |
368 | const STACK_OF(X509) *already_checked1, | |
369 | const STACK_OF(X509) *already_checked2, | |
370 | const OSSL_CMP_MSG *msg, int mode_3gpp) | |
371 | { | |
372 | int in_extraCerts = already_checked1 == NULL; | |
373 | int n_acceptable_certs = 0; | |
374 | int i; | |
375 | ||
376 | if (sk_X509_num(certs) <= 0) { | |
377 | ossl_cmp_log1(WARN, ctx, "no %s", desc); | |
378 | return 0; | |
379 | } | |
380 | ||
381 | for (i = 0; i < sk_X509_num(certs); i++) { /* certs may be NULL */ | |
382 | X509 *cert = sk_X509_value(certs, i); | |
383 | ||
384 | if (!ossl_assert(cert != NULL)) | |
385 | return 0; | |
386 | if (!cert_acceptable(ctx, "cert from", desc, cert, | |
387 | already_checked1, already_checked2, msg)) | |
388 | continue; | |
389 | n_acceptable_certs++; | |
390 | if (mode_3gpp ? check_msg_valid_cert_3gpp(ctx, cert, msg) | |
391 | : check_msg_valid_cert(ctx, ctx->trusted, cert, msg)) { | |
392 | /* store successful sender cert for further msgs in transaction */ | |
393 | if (!X509_up_ref(cert)) | |
394 | return 0; | |
395 | if (!ossl_cmp_ctx_set0_validatedSrvCert(ctx, cert)) { | |
396 | X509_free(cert); | |
397 | return 0; | |
398 | } | |
399 | return 1; | |
400 | } | |
401 | } | |
402 | if (in_extraCerts && n_acceptable_certs == 0) | |
403 | ossl_cmp_warn(ctx, "no acceptable cert in extraCerts"); | |
404 | return 0; | |
405 | } | |
406 | ||
407 | /* | |
408 | * Verify msg trying first ctx->untrusted_certs, which should include extraCerts | |
409 | * at its front, then trying the trusted certs in truststore (if any) of ctx. | |
410 | */ | |
411 | static int check_msg_all_certs(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg, | |
412 | int mode_3gpp) | |
413 | { | |
414 | int ret = 0; | |
415 | ||
416 | if (mode_3gpp | |
417 | && ((!ctx->permitTAInExtraCertsForIR | |
418 | || ossl_cmp_msg_get_bodytype(msg) != OSSL_CMP_PKIBODY_IP))) | |
419 | return 0; | |
420 | ||
421 | ossl_cmp_info(ctx, | |
422 | mode_3gpp ? "normal mode failed; trying now 3GPP mode trusting extraCerts" | |
423 | : "trying first normal mode using trust store"); | |
424 | if (check_msg_with_certs(ctx, msg->extraCerts, "extraCerts", | |
425 | NULL, NULL, msg, mode_3gpp)) | |
426 | return 1; | |
427 | if (check_msg_with_certs(ctx, ctx->untrusted_certs, "untrusted certs", | |
428 | msg->extraCerts, NULL, msg, mode_3gpp)) | |
429 | return 1; | |
430 | ||
431 | if (ctx->trusted == NULL) { | |
432 | ossl_cmp_warn(ctx, mode_3gpp ? "no self-issued extraCerts" | |
433 | : "no trusted store"); | |
434 | } else { | |
435 | STACK_OF(X509) *trusted = X509_STORE_get1_all_certs(ctx->trusted); | |
436 | ret = check_msg_with_certs(ctx, trusted, | |
437 | mode_3gpp ? "self-issued extraCerts" | |
438 | : "certs in trusted store", | |
439 | msg->extraCerts, ctx->untrusted_certs, | |
440 | msg, mode_3gpp); | |
441 | sk_X509_pop_free(trusted, X509_free); | |
442 | } | |
443 | return ret; | |
444 | } | |
445 | ||
446 | static int no_log_cb(const char *func, const char *file, int line, | |
447 | OSSL_CMP_severity level, const char *msg) | |
448 | { | |
449 | return 1; | |
450 | } | |
451 | ||
452 | /* verify message signature with any acceptable and valid candidate cert */ | |
453 | static int check_msg_find_cert(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg) | |
454 | { | |
455 | X509 *scrt = ctx->validatedSrvCert; /* previous successful sender cert */ | |
456 | GENERAL_NAME *sender = msg->header->sender; | |
457 | char *sname = NULL; | |
458 | char *skid_str = NULL; | |
459 | const ASN1_OCTET_STRING *skid = msg->header->senderKID; | |
460 | OSSL_CMP_log_cb_t backup_log_cb = ctx->log_cb; | |
461 | int res = 0; | |
462 | ||
463 | if (sender == NULL || msg->body == NULL) | |
464 | return 0; /* other NULL cases already have been checked */ | |
465 | if (sender->type != GEN_DIRNAME) { | |
466 | CMPerr(0, CMP_R_SENDER_GENERALNAME_TYPE_NOT_SUPPORTED); | |
467 | return 0; | |
468 | } | |
469 | ||
470 | /* dump any hitherto errors to avoid confusion when printing further ones */ | |
471 | OSSL_CMP_CTX_print_errors(ctx); | |
472 | ||
473 | /* | |
474 | * try first cached scrt, used successfully earlier in same transaction, | |
475 | * for validating this and any further msgs where extraCerts may be left out | |
476 | */ | |
477 | if (scrt != NULL) { | |
478 | (void)ERR_set_mark(); | |
479 | ossl_cmp_info(ctx, | |
480 | "trying to verify msg signature with previously validated cert"); | |
481 | if (cert_acceptable(ctx, "previously validated", "sender cert", scrt, | |
482 | NULL, NULL, msg) | |
483 | && (check_msg_valid_cert(ctx, ctx->trusted, scrt, msg) | |
484 | || check_msg_valid_cert_3gpp(ctx, scrt, msg))) { | |
485 | (void)ERR_pop_to_mark(); | |
486 | return 1; | |
487 | } | |
488 | (void)ERR_pop_to_mark(); | |
489 | /* cached sender cert has shown to be no more successfully usable */ | |
490 | (void)ossl_cmp_ctx_set0_validatedSrvCert(ctx, NULL); | |
491 | } | |
492 | ||
493 | /* enable clearing irrelevant errors in attempts to validate sender certs */ | |
494 | (void)ERR_set_mark(); | |
495 | ctx->log_cb = no_log_cb; /* temporarily disable logging */ | |
496 | res = check_msg_all_certs(ctx, msg, 0 /* using ctx->trusted */) | |
497 | || check_msg_all_certs(ctx, msg, 1 /* 3gpp */); | |
498 | ctx->log_cb = backup_log_cb; | |
499 | if (res) { | |
500 | /* discard any diagnostic information on trying to use certs */ | |
501 | (void)ERR_pop_to_mark(); | |
502 | goto end; | |
503 | } | |
504 | /* failed finding a sender cert that verifies the message signature */ | |
505 | (void)ERR_clear_last_mark(); | |
506 | ||
507 | sname = X509_NAME_oneline(sender->d.directoryName, NULL, 0); | |
508 | skid_str = skid == NULL ? NULL | |
509 | : OPENSSL_buf2hexstr(skid->data, skid->length); | |
510 | if (ctx->log_cb != NULL) { | |
511 | ossl_cmp_info(ctx, "trying to verify msg signature with a valid cert that.."); | |
512 | if (sname != NULL) | |
513 | ossl_cmp_log1(INFO, ctx, "matches msg sender = %s", sname); | |
514 | if (skid_str != NULL) | |
515 | ossl_cmp_log1(INFO, ctx, "matches msg senderKID = %s", skid_str); | |
516 | else | |
517 | ossl_cmp_info(ctx, "while msg header does not contain senderKID"); | |
518 | /* re-do the above checks (just) for adding diagnostic information */ | |
519 | check_msg_all_certs(ctx, msg, 0 /* using ctx->trusted */); | |
520 | check_msg_all_certs(ctx, msg, 1 /* 3gpp */); | |
521 | } | |
522 | ||
523 | CMPerr(0, CMP_R_NO_SUITABLE_SENDER_CERT); | |
524 | if (sname != NULL) { | |
525 | ERR_add_error_txt(NULL, "for msg sender name = "); | |
526 | ERR_add_error_txt(NULL, sname); | |
527 | } | |
528 | if (skid_str != NULL) { | |
529 | ERR_add_error_txt(" and ", "for msg senderKID = "); | |
530 | ERR_add_error_txt(NULL, skid_str); | |
531 | } | |
532 | ||
533 | end: | |
534 | OPENSSL_free(sname); | |
535 | OPENSSL_free(skid_str); | |
536 | return res; | |
537 | } | |
538 | ||
539 | /* | |
540 | * Validate the protection of the given PKIMessage using either password- | |
541 | * based mac (PBM) or a signature algorithm. In the case of signature algorithm, | |
542 | * the sender certificate can have been pinned by providing it in ctx->srvCert, | |
543 | * else it is searched in msg->extraCerts, ctx->untrusted_certs, in ctx->trusted | |
544 | * (in this order) and is path is validated against ctx->trusted. | |
545 | * | |
546 | * If ctx->permitTAInExtraCertsForIR is true and when validating a CMP IP msg, | |
547 | * the trust anchor for validating the IP msg may be taken from msg->extraCerts | |
548 | * if a self-issued certificate is found there that can be used to | |
549 | * validate the enrolled certificate returned in the IP. | |
550 | * This is according to the need given in 3GPP TS 33.310. | |
551 | * | |
552 | * Returns 1 on success, 0 on error or validation failed. | |
553 | */ | |
554 | int OSSL_CMP_validate_msg(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg) | |
555 | { | |
556 | X509_ALGOR *alg; | |
557 | int nid = NID_undef, pk_nid = NID_undef; | |
558 | const ASN1_OBJECT *algorOID = NULL; | |
559 | X509 *scrt; | |
560 | ||
561 | if (ctx == NULL || msg == NULL | |
562 | || msg->header == NULL || msg->body == NULL) { | |
563 | CMPerr(0, CMP_R_NULL_ARGUMENT); | |
564 | return 0; | |
565 | } | |
566 | ||
567 | if ((alg = msg->header->protectionAlg) == NULL /* unprotected message */ | |
568 | || msg->protection == NULL || msg->protection->data == NULL) { | |
569 | CMPerr(0, CMP_R_MISSING_PROTECTION); | |
570 | return 0; | |
571 | } | |
572 | ||
573 | /* determine the nid for the used protection algorithm */ | |
574 | X509_ALGOR_get0(&algorOID, NULL, NULL, alg); | |
575 | nid = OBJ_obj2nid(algorOID); | |
576 | ||
577 | switch (nid) { | |
578 | /* 5.1.3.1. Shared Secret Information */ | |
579 | case NID_id_PasswordBasedMAC: | |
580 | if (ctx->secretValue == 0) { | |
581 | CMPerr(0, CMP_R_CHECKING_PBM_NO_SECRET_AVAILABLE); | |
582 | break; | |
583 | } | |
584 | ||
585 | if (verify_PBMAC(msg, ctx->secretValue)) { | |
586 | /* | |
587 | * RFC 4210, 5.3.2: 'Note that if the PKI Message Protection is | |
588 | * "shared secret information", then any certificate transported in | |
589 | * the caPubs field may be directly trusted as a root CA | |
590 | * certificate by the initiator.' | |
591 | */ | |
592 | switch (ossl_cmp_msg_get_bodytype(msg)) { | |
593 | case -1: | |
594 | return 0; | |
595 | case OSSL_CMP_PKIBODY_IP: | |
596 | case OSSL_CMP_PKIBODY_CP: | |
597 | case OSSL_CMP_PKIBODY_KUP: | |
598 | case OSSL_CMP_PKIBODY_CCP: | |
599 | if (ctx->trusted != NULL) { | |
600 | STACK_OF(X509) *certs = msg->body->value.ip->caPubs; | |
601 | /* value.ip is same for cp, kup, and ccp */ | |
602 | ||
603 | if (!ossl_cmp_X509_STORE_add1_certs(ctx->trusted, certs, 0)) | |
604 | /* adds both self-issued and not self-issued certs */ | |
605 | return 0; | |
606 | } | |
607 | break; | |
608 | default: | |
609 | break; | |
610 | } | |
611 | return 1; | |
612 | } | |
613 | break; | |
614 | ||
615 | /* | |
616 | * 5.1.3.2 DH Key Pairs | |
617 | * Not yet supported | |
618 | */ | |
619 | case NID_id_DHBasedMac: | |
620 | CMPerr(0, CMP_R_UNSUPPORTED_PROTECTION_ALG_DHBASEDMAC); | |
621 | break; | |
622 | ||
623 | /* | |
624 | * 5.1.3.3. Signature | |
625 | */ | |
626 | default: | |
627 | if (!OBJ_find_sigid_algs(OBJ_obj2nid(alg->algorithm), NULL, &pk_nid) | |
628 | || pk_nid == NID_undef) { | |
629 | CMPerr(0, CMP_R_UNKNOWN_ALGORITHM_ID); | |
630 | break; | |
631 | } | |
632 | /* validate sender name of received msg */ | |
633 | if (msg->header->sender->type != GEN_DIRNAME) { | |
634 | CMPerr(0, CMP_R_SENDER_GENERALNAME_TYPE_NOT_SUPPORTED); | |
635 | break; /* FR#42: support for more than X509_NAME */ | |
636 | } | |
637 | /* | |
638 | * Compare actual sender name of response with expected sender name. | |
639 | * Expected name can be set explicitly or the subject of ctx->srvCert. | |
640 | * Mitigates risk to accept misused certificate of an unauthorized | |
641 | * entity of a trusted hierarchy. | |
642 | */ | |
643 | if (!check_name(ctx, "sender DN field", | |
644 | msg->header->sender->d.directoryName, | |
645 | "expected sender", ctx->expected_sender)) | |
646 | break; | |
647 | /* Note: if recipient was NULL-DN it could be learned here if needed */ | |
648 | ||
649 | scrt = ctx->srvCert; | |
650 | if (scrt == NULL) { | |
651 | if (check_msg_find_cert(ctx, msg)) | |
652 | return 1; | |
653 | } else { /* use pinned sender cert */ | |
654 | /* use ctx->srvCert for signature check even if not acceptable */ | |
655 | if (verify_signature(ctx, msg, scrt)) | |
656 | return 1; | |
657 | /* call cert_acceptable() for adding diagnostic information */ | |
658 | (void)cert_acceptable(ctx, "explicitly set", "sender cert", scrt, | |
659 | NULL, NULL, msg); | |
660 | ossl_cmp_warn(ctx, "msg signature verification failed"); | |
661 | CMPerr(0, CMP_R_SRVCERT_DOES_NOT_VALIDATE_MSG); | |
662 | } | |
663 | break; | |
664 | } | |
665 | return 0; | |
666 | } | |
667 | ||
668 | ||
669 | /*- | |
670 | * Check received message (i.e., response by server or request from client) | |
671 | * Any msg->extraCerts are prepended to ctx->untrusted_certs | |
672 | * | |
673 | * Ensures that: | |
674 | * it has a valid body type | |
675 | * its protection is valid (or invalid/absent, but only if a callback function | |
676 | * is present and yields a positive result using also the supplied argument) | |
677 | * its transaction ID matches the previous transaction ID stored in ctx (if any) | |
678 | * its recipNonce matches the previous senderNonce stored in the ctx (if any) | |
679 | * | |
680 | * If everything is fine: | |
681 | * learns the senderNonce from the received message, | |
682 | * learns the transaction ID if it is not yet in ctx. | |
683 | * | |
684 | * returns body type (which is >= 0) of the message on success, -1 on error | |
685 | */ | |
686 | int ossl_cmp_msg_check_received(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg, | |
687 | ossl_cmp_allow_unprotected_cb_t cb, int cb_arg) | |
688 | { | |
689 | int rcvd_type; | |
690 | ||
691 | if (!ossl_assert(ctx != NULL && msg != NULL)) | |
692 | return -1; | |
693 | ||
694 | if (sk_X509_num(msg->extraCerts) > 10) | |
695 | ossl_cmp_warn(ctx, | |
696 | "received CMP message contains more than 10 extraCerts"); | |
697 | ||
698 | /* validate message protection */ | |
699 | if (msg->header->protectionAlg != 0) { | |
700 | /* detect explicitly permitted exceptions for invalid protection */ | |
701 | if (!OSSL_CMP_validate_msg(ctx, msg) | |
702 | && (cb == NULL || (*cb)(ctx, msg, 1, cb_arg) <= 0)) { | |
703 | CMPerr(0, CMP_R_ERROR_VALIDATING_PROTECTION); | |
704 | return -1; | |
705 | } | |
706 | } else { | |
707 | /* detect explicitly permitted exceptions for missing protection */ | |
708 | if (cb == NULL || (*cb)(ctx, msg, 0, cb_arg) <= 0) { | |
709 | CMPerr(0, CMP_R_MISSING_PROTECTION); | |
710 | return -1; | |
711 | } | |
712 | } | |
713 | ||
714 | /* check CMP version number in header */ | |
715 | if (ossl_cmp_hdr_get_pvno(OSSL_CMP_MSG_get0_header(msg)) != OSSL_CMP_PVNO) { | |
716 | CMPerr(0, CMP_R_UNEXPECTED_PVNO); | |
717 | return -1; | |
718 | } | |
719 | ||
720 | if ((rcvd_type = ossl_cmp_msg_get_bodytype(msg)) < 0) { | |
721 | CMPerr(0, CMP_R_PKIBODY_ERROR); | |
722 | return -1; | |
723 | } | |
724 | ||
725 | /* compare received transactionID with the expected one in previous msg */ | |
726 | if (ctx->transactionID != NULL | |
727 | && (msg->header->transactionID == NULL | |
728 | || ASN1_OCTET_STRING_cmp(ctx->transactionID, | |
729 | msg->header->transactionID) != 0)) { | |
730 | CMPerr(0, CMP_R_TRANSACTIONID_UNMATCHED); | |
731 | return -1; | |
732 | } | |
733 | ||
734 | /* compare received nonce with the one we sent */ | |
735 | if (ctx->senderNonce != NULL | |
736 | && (msg->header->recipNonce == NULL | |
737 | || ASN1_OCTET_STRING_cmp(ctx->senderNonce, | |
738 | msg->header->recipNonce) != 0)) { | |
739 | CMPerr(0, CMP_R_RECIPNONCE_UNMATCHED); | |
740 | return -1; | |
741 | } | |
742 | ||
743 | /* | |
744 | * RFC 4210 section 5.1.1 states: the recipNonce is copied from | |
745 | * the senderNonce of the previous message in the transaction. | |
746 | * --> Store for setting in next message | |
747 | */ | |
748 | if (!ossl_cmp_ctx_set1_recipNonce(ctx, msg->header->senderNonce)) | |
749 | return -1; | |
750 | ||
751 | /* if not yet present, learn transactionID */ | |
752 | if (ctx->transactionID == NULL | |
753 | && !OSSL_CMP_CTX_set1_transactionID(ctx, msg->header->transactionID)) | |
754 | return -1; | |
755 | ||
756 | /* | |
757 | * Store any provided extraCerts in ctx for future use, | |
758 | * such that they are available to ctx->certConf_cb and | |
759 | * the peer does not need to send them again in the same transaction. | |
760 | * For efficiency, the extraCerts are prepended so they get used first. | |
761 | */ | |
762 | if (!ossl_cmp_sk_X509_add1_certs(ctx->untrusted_certs, msg->extraCerts, | |
763 | 0 /* this allows self-issued certs */, | |
764 | 1 /* no_dups */, 1 /* prepend */)) | |
765 | return -1; | |
766 | ||
767 | return rcvd_type; | |
768 | } | |
769 | ||
770 | int ossl_cmp_verify_popo(const OSSL_CMP_MSG *msg, int accept_RAVerified) | |
771 | { | |
772 | if (!ossl_assert(msg != NULL && msg->body != NULL)) | |
773 | return 0; | |
774 | switch (msg->body->type) { | |
775 | case OSSL_CMP_PKIBODY_P10CR: | |
776 | { | |
777 | X509_REQ *req = msg->body->value.p10cr; | |
778 | ||
779 | if (X509_REQ_verify(req, X509_REQ_get0_pubkey(req)) > 0) | |
780 | return 1; | |
781 | CMPerr(0, CMP_R_REQUEST_NOT_ACCEPTED); | |
782 | return 0; | |
783 | } | |
784 | case OSSL_CMP_PKIBODY_IR: | |
785 | case OSSL_CMP_PKIBODY_CR: | |
786 | case OSSL_CMP_PKIBODY_KUR: | |
787 | return OSSL_CRMF_MSGS_verify_popo(msg->body->value.ir, | |
788 | OSSL_CMP_CERTREQID, | |
789 | accept_RAVerified); | |
790 | default: | |
791 | CMPerr(0, CMP_R_PKIBODY_ERROR); | |
792 | return 0; | |
793 | } | |
794 | } |