1 /* 2 * Copyright 2007-2024 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 24 /* Verify a message protected by signature according to RFC section 5.1.3.3 */ 25 static int verify_signature(const OSSL_CMP_CTX *cmp_ctx, 26 const OSSL_CMP_MSG *msg, X509 *cert) 27 { 28 OSSL_CMP_PROTECTEDPART prot_part; 29 EVP_PKEY *pubkey = NULL; 30 BIO *bio; 31 int res = 0; 32 33 if (!ossl_assert(cmp_ctx != NULL && msg != NULL && cert != NULL)) 34 return 0; 35 36 bio = BIO_new(BIO_s_mem()); /* may be NULL */ 37 if (bio == NULL) 38 return 0; 39 /* verify that keyUsage, if present, contains digitalSignature */ 40 if (!cmp_ctx->ignore_keyusage 41 && (X509_get_key_usage(cert) & X509v3_KU_DIGITAL_SIGNATURE) == 0) { 42 ERR_raise(ERR_LIB_CMP, CMP_R_MISSING_KEY_USAGE_DIGITALSIGNATURE); 43 goto sig_err; 44 } 45 46 pubkey = X509_get_pubkey(cert); 47 if (pubkey == NULL) { 48 ERR_raise(ERR_LIB_CMP, CMP_R_FAILED_EXTRACTING_PUBKEY); 49 goto sig_err; 50 } 51 52 prot_part.header = msg->header; 53 prot_part.body = msg->body; 54 55 if (ASN1_item_verify_ex(ASN1_ITEM_rptr(OSSL_CMP_PROTECTEDPART), 56 msg->header->protectionAlg, msg->protection, 57 &prot_part, NULL, pubkey, cmp_ctx->libctx, 58 cmp_ctx->propq) > 0) { 59 res = 1; 60 goto end; 61 } 62 63 sig_err: 64 res = ossl_x509_print_ex_brief(bio, cert, X509_FLAG_NO_EXTENSIONS); 65 ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_VALIDATING_SIGNATURE); 66 if (res) 67 ERR_add_error_mem_bio("\n", bio); 68 res = 0; 69 70 end: 71 EVP_PKEY_free(pubkey); 72 BIO_free(bio); 73 74 return res; 75 } 76 77 /* Verify a message protected with PBMAC */ 78 static int verify_PBMAC(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg) 79 { 80 ASN1_BIT_STRING *protection = NULL; 81 int valid = 0; 82 83 /* generate expected protection for the message */ 84 if ((protection = ossl_cmp_calc_protection(ctx, msg)) == NULL) 85 return 0; /* failed to generate protection string! */ 86 87 valid = msg->protection != NULL && msg->protection->length >= 0 88 && msg->protection->type == protection->type 89 && msg->protection->length == protection->length 90 && CRYPTO_memcmp(msg->protection->data, protection->data, 91 protection->length) == 0; 92 ASN1_BIT_STRING_free(protection); 93 if (!valid) 94 ERR_raise(ERR_LIB_CMP, CMP_R_WRONG_PBM_VALUE); 95 96 return valid; 97 } 98 99 /*- 100 * Attempt to validate certificate and path using any given store with trusted 101 * certs (possibly including CRLs and a cert verification callback function) 102 * and non-trusted intermediate certs from the given ctx. 103 * 104 * Returns 1 on successful validation and 0 otherwise. 105 */ 106 int OSSL_CMP_validate_cert_path(const OSSL_CMP_CTX *ctx, 107 X509_STORE *trusted_store, X509 *cert) 108 { 109 int valid = 0; 110 X509_STORE_CTX *csc = NULL; 111 int err; 112 113 if (ctx == NULL || cert == NULL) { 114 ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT); 115 return 0; 116 } 117 118 if (trusted_store == NULL) { 119 ERR_raise(ERR_LIB_CMP, CMP_R_MISSING_TRUST_STORE); 120 return 0; 121 } 122 123 if ((csc = X509_STORE_CTX_new_ex(ctx->libctx, ctx->propq)) == NULL 124 || !X509_STORE_CTX_init(csc, trusted_store, 125 cert, ctx->untrusted)) 126 goto err; 127 128 valid = X509_verify_cert(csc) > 0; 129 130 /* make sure suitable error is queued even if callback did not do */ 131 err = ERR_peek_last_error(); 132 if (!valid && ERR_GET_REASON(err) != CMP_R_POTENTIALLY_INVALID_CERTIFICATE) 133 ERR_raise(ERR_LIB_CMP, CMP_R_POTENTIALLY_INVALID_CERTIFICATE); 134 135 err: 136 /* directly output any fresh errors, needed for check_msg_find_cert() */ 137 OSSL_CMP_CTX_print_errors(ctx); 138 X509_STORE_CTX_free(csc); 139 return valid; 140 } 141 142 static int verify_cb_cert(X509_STORE *ts, X509 *cert, int err) 143 { 144 X509_STORE_CTX_verify_cb verify_cb; 145 X509_STORE_CTX *csc; 146 int ok = 0; 147 148 if (ts == NULL || (verify_cb = X509_STORE_get_verify_cb(ts)) == NULL) 149 return ok; 150 if ((csc = X509_STORE_CTX_new()) != NULL 151 && X509_STORE_CTX_init(csc, ts, cert, NULL)) { 152 X509_STORE_CTX_set_error(csc, err); 153 X509_STORE_CTX_set_current_cert(csc, cert); 154 ok = (*verify_cb)(0, csc); 155 } 156 X509_STORE_CTX_free(csc); 157 return ok; 158 } 159 160 /* Return 0 if expect_name != NULL and there is no matching actual_name */ 161 static int check_name(const OSSL_CMP_CTX *ctx, int log_success, 162 const char *actual_desc, const X509_NAME *actual_name, 163 const char *expect_desc, const X509_NAME *expect_name) 164 { 165 char *str; 166 167 if (expect_name == NULL) 168 return 1; /* no expectation, thus trivially fulfilled */ 169 170 /* make sure that a matching name is there */ 171 if (actual_name == NULL) { 172 ossl_cmp_log1(WARN, ctx, "missing %s", actual_desc); 173 return 0; 174 } 175 str = X509_NAME_oneline(actual_name, NULL, 0); 176 if (X509_NAME_cmp(actual_name, expect_name) == 0) { 177 if (log_success && str != NULL) 178 ossl_cmp_log3(INFO, ctx, " %s matches %s: %s", 179 actual_desc, expect_desc, str); 180 OPENSSL_free(str); 181 return 1; 182 } 183 184 if (str != NULL) 185 ossl_cmp_log2(INFO, ctx, " actual name in %s = %s", actual_desc, str); 186 OPENSSL_free(str); 187 if ((str = X509_NAME_oneline(expect_name, NULL, 0)) != NULL) 188 ossl_cmp_log2(INFO, ctx, " does not match %s = %s", expect_desc, str); 189 OPENSSL_free(str); 190 return 0; 191 } 192 193 /* Return 0 if skid != NULL and there is no matching subject key ID in cert */ 194 static int check_kid(const OSSL_CMP_CTX *ctx, 195 const ASN1_OCTET_STRING *ckid, 196 const ASN1_OCTET_STRING *skid) 197 { 198 char *str; 199 200 if (skid == NULL) 201 return 1; /* no expectation, thus trivially fulfilled */ 202 203 /* make sure that the expected subject key identifier is there */ 204 if (ckid == NULL) { 205 ossl_cmp_warn(ctx, "missing Subject Key Identifier in certificate"); 206 return 0; 207 } 208 str = i2s_ASN1_OCTET_STRING(NULL, ckid); 209 if (ASN1_OCTET_STRING_cmp(ckid, skid) == 0) { 210 if (str != NULL) 211 ossl_cmp_log1(INFO, ctx, " subjectKID matches senderKID: %s", str); 212 OPENSSL_free(str); 213 return 1; 214 } 215 216 if (str != NULL) 217 ossl_cmp_log1(INFO, ctx, " cert Subject Key Identifier = %s", str); 218 OPENSSL_free(str); 219 if ((str = i2s_ASN1_OCTET_STRING(NULL, skid)) != NULL) 220 ossl_cmp_log1(INFO, ctx, " does not match senderKID = %s", str); 221 OPENSSL_free(str); 222 return 0; 223 } 224 225 static int already_checked(const X509 *cert, 226 const STACK_OF(X509) *already_checked) 227 { 228 int i; 229 230 for (i = sk_X509_num(already_checked /* may be NULL */); i > 0; i--) 231 if (X509_cmp(sk_X509_value(already_checked, i - 1), cert) == 0) 232 return 1; 233 return 0; 234 } 235 236 /*- 237 * Check if the given cert is acceptable as sender cert of the given message. 238 * The subject DN must match, the subject key ID as well if present in the msg, 239 * and the cert must be current (checked if ctx->trusted is not NULL). 240 * Note that cert revocation etc. is checked by OSSL_CMP_validate_cert_path(). 241 * 242 * Returns 0 on error or not acceptable, else 1. 243 */ 244 static int cert_acceptable(const OSSL_CMP_CTX *ctx, 245 const char *desc1, const char *desc2, X509 *cert, 246 const STACK_OF(X509) *already_checked1, 247 const STACK_OF(X509) *already_checked2, 248 const OSSL_CMP_MSG *msg) 249 { 250 X509_STORE *ts = ctx->trusted; 251 int self_issued = X509_check_issued(cert, cert) == X509_V_OK; 252 char *str; 253 X509_VERIFY_PARAM *vpm = ts != NULL ? X509_STORE_get0_param(ts) : NULL; 254 int time_cmp; 255 256 ossl_cmp_log3(INFO, ctx, " considering %s%s %s with..", 257 self_issued ? "self-issued ": "", desc1, desc2); 258 if ((str = X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0)) != NULL) 259 ossl_cmp_log1(INFO, ctx, " subject = %s", str); 260 OPENSSL_free(str); 261 if (!self_issued) { 262 str = X509_NAME_oneline(X509_get_issuer_name(cert), NULL, 0); 263 if (str != NULL) 264 ossl_cmp_log1(INFO, ctx, " issuer = %s", str); 265 OPENSSL_free(str); 266 } 267 268 if (already_checked(cert, already_checked1) 269 || already_checked(cert, already_checked2)) { 270 ossl_cmp_info(ctx, " cert has already been checked"); 271 return 0; 272 } 273 274 time_cmp = X509_cmp_timeframe(vpm, X509_get0_notBefore(cert), 275 X509_get0_notAfter(cert)); 276 if (time_cmp != 0) { 277 int err = time_cmp > 0 ? X509_V_ERR_CERT_HAS_EXPIRED 278 : X509_V_ERR_CERT_NOT_YET_VALID; 279 280 ossl_cmp_warn(ctx, time_cmp > 0 ? "cert has expired" 281 : "cert is not yet valid"); 282 if (ctx->log_cb != NULL /* logging not temporarily disabled */ 283 && verify_cb_cert(ts, cert, err) <= 0) 284 return 0; 285 } 286 287 if (!check_name(ctx, 1, 288 "cert subject", X509_get_subject_name(cert), 289 "sender field", msg->header->sender->d.directoryName)) 290 return 0; 291 292 if (!check_kid(ctx, X509_get0_subject_key_id(cert), msg->header->senderKID)) 293 return 0; 294 /* prevent misleading error later in case x509v3_cache_extensions() fails */ 295 if (!ossl_x509v3_cache_extensions(cert)) { 296 ossl_cmp_warn(ctx, "cert appears to be invalid"); 297 return 0; 298 } 299 if (!verify_signature(ctx, msg, cert)) { 300 ossl_cmp_warn(ctx, "msg signature verification failed"); 301 return 0; 302 } 303 /* acceptable also if there is no senderKID in msg header */ 304 ossl_cmp_info(ctx, " cert seems acceptable"); 305 return 1; 306 } 307 308 static int check_cert_path(const OSSL_CMP_CTX *ctx, X509_STORE *store, 309 X509 *scrt) 310 { 311 if (OSSL_CMP_validate_cert_path(ctx, store, scrt)) 312 return 1; 313 314 ossl_cmp_warn(ctx, 315 "msg signature validates but cert path validation failed"); 316 return 0; 317 } 318 319 /* 320 * Exceptional handling for 3GPP TS 33.310 [3G/LTE Network Domain Security 321 * (NDS); Authentication Framework (AF)], only to use for IP messages 322 * and if the ctx option is explicitly set: use self-issued certificates 323 * from extraCerts as trust anchor to validate sender cert - 324 * provided it also can validate the newly enrolled certificate 325 */ 326 static int check_cert_path_3gpp(const OSSL_CMP_CTX *ctx, 327 const OSSL_CMP_MSG *msg, X509 *scrt) 328 { 329 int valid = 0; 330 X509_STORE *store; 331 332 if (!ctx->permitTAInExtraCertsForIR) 333 return 0; 334 335 if ((store = X509_STORE_new()) == NULL 336 || !ossl_cmp_X509_STORE_add1_certs(store, msg->extraCerts, 337 1 /* self-issued only */)) 338 goto err; 339 340 /* store does not include CRLs */ 341 valid = OSSL_CMP_validate_cert_path(ctx, store, scrt); 342 if (!valid) { 343 ossl_cmp_warn(ctx, 344 "also exceptional 3GPP mode cert path validation failed"); 345 } else { 346 /* 347 * verify that the newly enrolled certificate (which assumed rid == 348 * OSSL_CMP_CERTREQID) can also be validated with the same trusted store 349 */ 350 OSSL_CMP_CERTRESPONSE *crep = 351 ossl_cmp_certrepmessage_get0_certresponse(msg->body->value.ip, 352 OSSL_CMP_CERTREQID); 353 X509 *newcrt = ossl_cmp_certresponse_get1_cert(ctx, crep); 354 355 /* 356 * maybe better use get_cert_status() from cmp_client.c, which catches 357 * errors 358 */ 359 valid = OSSL_CMP_validate_cert_path(ctx, store, newcrt); 360 X509_free(newcrt); 361 } 362 363 err: 364 X509_STORE_free(store); 365 return valid; 366 } 367 368 static int check_msg_given_cert(const OSSL_CMP_CTX *ctx, X509 *cert, 369 const OSSL_CMP_MSG *msg) 370 { 371 return cert_acceptable(ctx, "previously validated", "sender cert", 372 cert, NULL, NULL, msg) 373 && (check_cert_path(ctx, ctx->trusted, cert) 374 || check_cert_path_3gpp(ctx, msg, cert)); 375 } 376 377 /*- 378 * Try all certs in given list for verifying msg, normally or in 3GPP mode. 379 * If already_checked1 == NULL then certs are assumed to be the msg->extraCerts. 380 * On success cache the found cert using ossl_cmp_ctx_set1_validatedSrvCert(). 381 */ 382 static int check_msg_with_certs(OSSL_CMP_CTX *ctx, const STACK_OF(X509) *certs, 383 const char *desc, 384 const STACK_OF(X509) *already_checked1, 385 const STACK_OF(X509) *already_checked2, 386 const OSSL_CMP_MSG *msg, int mode_3gpp) 387 { 388 int in_extraCerts = already_checked1 == NULL; 389 int n_acceptable_certs = 0; 390 int i; 391 392 if (sk_X509_num(certs) <= 0) { 393 ossl_cmp_log1(WARN, ctx, "no %s", desc); 394 return 0; 395 } 396 397 for (i = 0; i < sk_X509_num(certs); i++) { /* certs may be NULL */ 398 X509 *cert = sk_X509_value(certs, i); 399 400 if (!ossl_assert(cert != NULL)) 401 return 0; 402 if (!cert_acceptable(ctx, "cert from", desc, cert, 403 already_checked1, already_checked2, msg)) 404 continue; 405 n_acceptable_certs++; 406 if (mode_3gpp ? check_cert_path_3gpp(ctx, msg, cert) 407 : check_cert_path(ctx, ctx->trusted, cert)) { 408 /* store successful sender cert for further msgs in transaction */ 409 return ossl_cmp_ctx_set1_validatedSrvCert(ctx, cert); 410 } 411 } 412 if (in_extraCerts && n_acceptable_certs == 0) 413 ossl_cmp_warn(ctx, "no acceptable cert in extraCerts"); 414 return 0; 415 } 416 417 /*- 418 * Verify msg trying first ctx->untrusted, which should include extraCerts 419 * at its front, then trying the trusted certs in truststore (if any) of ctx. 420 * On success cache the found cert using ossl_cmp_ctx_set1_validatedSrvCert(). 421 */ 422 static int check_msg_all_certs(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg, 423 int mode_3gpp) 424 { 425 int ret = 0; 426 427 if (ctx->permitTAInExtraCertsForIR 428 && OSSL_CMP_MSG_get_bodytype(msg) == OSSL_CMP_PKIBODY_IP) 429 ossl_cmp_info(ctx, mode_3gpp ? 430 "normal mode failed; trying now 3GPP mode trusting extraCerts" 431 : "trying first normal mode using trust store"); 432 else if (mode_3gpp) 433 return 0; 434 435 if (check_msg_with_certs(ctx, msg->extraCerts, "extraCerts", 436 NULL, NULL, msg, mode_3gpp)) 437 return 1; 438 if (check_msg_with_certs(ctx, ctx->untrusted, "untrusted certs", 439 msg->extraCerts, NULL, msg, mode_3gpp)) 440 return 1; 441 442 if (ctx->trusted == NULL) { 443 ossl_cmp_warn(ctx, mode_3gpp ? "no self-issued extraCerts" 444 : "no trusted store"); 445 } else { 446 STACK_OF(X509) *trusted = X509_STORE_get1_all_certs(ctx->trusted); 447 448 ret = check_msg_with_certs(ctx, trusted, 449 mode_3gpp ? "self-issued extraCerts" 450 : "certs in trusted store", 451 msg->extraCerts, ctx->untrusted, 452 msg, mode_3gpp); 453 OSSL_STACK_OF_X509_free(trusted); 454 } 455 return ret; 456 } 457 458 /*- 459 * Verify message signature with any acceptable and valid candidate cert. 460 * On success cache the found cert using ossl_cmp_ctx_set1_validatedSrvCert(). 461 */ 462 static int check_msg_find_cert(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg) 463 { 464 X509 *scrt = ctx->validatedSrvCert; /* previous successful sender cert */ 465 GENERAL_NAME *sender = msg->header->sender; 466 char *sname = NULL; 467 char *skid_str = NULL; 468 const ASN1_OCTET_STRING *skid = msg->header->senderKID; 469 OSSL_CMP_log_cb_t backup_log_cb = ctx->log_cb; 470 int res = 0; 471 472 if (sender == NULL || msg->body == NULL) 473 return 0; /* other NULL cases already have been checked */ 474 if (sender->type != GEN_DIRNAME) { 475 /* So far, only X509_NAME is supported */ 476 ERR_raise(ERR_LIB_CMP, CMP_R_SENDER_GENERALNAME_TYPE_NOT_SUPPORTED); 477 return 0; 478 } 479 480 /* dump any hitherto errors to avoid confusion when printing further ones */ 481 OSSL_CMP_CTX_print_errors(ctx); 482 483 /* enable clearing irrelevant errors in attempts to validate sender certs */ 484 (void)ERR_set_mark(); 485 ctx->log_cb = NULL; /* temporarily disable logging */ 486 487 /* 488 * try first cached scrt, used successfully earlier in same transaction, 489 * for validating this and any further msgs where extraCerts may be left out 490 */ 491 if (scrt != NULL) { 492 if (check_msg_given_cert(ctx, scrt, msg)) { 493 ctx->log_cb = backup_log_cb; 494 (void)ERR_pop_to_mark(); 495 return 1; 496 } 497 /* cached sender cert has shown to be no more successfully usable */ 498 (void)ossl_cmp_ctx_set1_validatedSrvCert(ctx, NULL); 499 /* re-do the above check (just) for adding diagnostic information */ 500 ossl_cmp_info(ctx, 501 "trying to verify msg signature with previously validated cert"); 502 (void)check_msg_given_cert(ctx, scrt, msg); 503 } 504 505 res = check_msg_all_certs(ctx, msg, 0 /* using ctx->trusted */) 506 || check_msg_all_certs(ctx, msg, 1 /* 3gpp */); 507 ctx->log_cb = backup_log_cb; 508 if (res) { 509 /* discard any diagnostic information on trying to use certs */ 510 (void)ERR_pop_to_mark(); 511 goto end; 512 } 513 /* failed finding a sender cert that verifies the message signature */ 514 (void)ERR_clear_last_mark(); 515 516 sname = X509_NAME_oneline(sender->d.directoryName, NULL, 0); 517 skid_str = skid == NULL ? NULL : i2s_ASN1_OCTET_STRING(NULL, skid); 518 if (ctx->log_cb != NULL) { 519 ossl_cmp_info(ctx, "trying to verify msg signature with a valid cert that.."); 520 if (sname != NULL) 521 ossl_cmp_log1(INFO, ctx, "matches msg sender = %s", sname); 522 if (skid_str != NULL) 523 ossl_cmp_log1(INFO, ctx, "matches msg senderKID = %s", skid_str); 524 else 525 ossl_cmp_info(ctx, "while msg header does not contain senderKID"); 526 /* re-do the above checks (just) for adding diagnostic information */ 527 (void)check_msg_all_certs(ctx, msg, 0 /* using ctx->trusted */); 528 (void)check_msg_all_certs(ctx, msg, 1 /* 3gpp */); 529 } 530 531 ERR_raise(ERR_LIB_CMP, CMP_R_NO_SUITABLE_SENDER_CERT); 532 if (sname != NULL) { 533 ERR_add_error_txt(NULL, "for msg sender name = "); 534 ERR_add_error_txt(NULL, sname); 535 } 536 if (skid_str != NULL) { 537 ERR_add_error_txt(" and ", "for msg senderKID = "); 538 ERR_add_error_txt(NULL, skid_str); 539 } 540 541 end: 542 OPENSSL_free(sname); 543 OPENSSL_free(skid_str); 544 return res; 545 } 546 547 /*- 548 * Validate the protection of the given PKIMessage using either password- 549 * based mac (PBM) or a signature algorithm. In the case of signature algorithm, 550 * the sender certificate can have been pinned by providing it in ctx->srvCert, 551 * else it is searched in msg->extraCerts, ctx->untrusted, in ctx->trusted 552 * (in this order) and is path is validated against ctx->trusted. 553 * On success cache the found cert using ossl_cmp_ctx_set1_validatedSrvCert(). 554 * 555 * If ctx->permitTAInExtraCertsForIR is true and when validating a CMP IP msg, 556 * the trust anchor for validating the IP msg may be taken from msg->extraCerts 557 * if a self-issued certificate is found there that can be used to 558 * validate the enrolled certificate returned in the IP. 559 * This is according to the need given in 3GPP TS 33.310. 560 * 561 * Returns 1 on success, 0 on error or validation failed. 562 */ 563 int OSSL_CMP_validate_msg(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg) 564 { 565 X509 *scrt; 566 567 ossl_cmp_debug(ctx, "validating CMP message"); 568 if (ctx == NULL || msg == NULL 569 || msg->header == NULL || msg->body == NULL) { 570 ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT); 571 return 0; 572 } 573 574 if (msg->header->protectionAlg == NULL /* unprotected message */ 575 || msg->protection == NULL || msg->protection->data == NULL) { 576 ERR_raise(ERR_LIB_CMP, CMP_R_MISSING_PROTECTION); 577 return 0; 578 } 579 580 switch (ossl_cmp_hdr_get_protection_nid(msg->header)) { 581 /* 5.1.3.1. Shared Secret Information */ 582 case NID_id_PasswordBasedMAC: 583 if (ctx->secretValue == NULL) { 584 ossl_cmp_info(ctx, "no secret available for verifying PBM-based CMP message protection"); 585 ERR_raise(ERR_LIB_CMP, CMP_R_MISSING_SECRET); 586 return 0; 587 } 588 if (verify_PBMAC(ctx, msg)) { 589 /* 590 * RFC 4210, 5.3.2: 'Note that if the PKI Message Protection is 591 * "shared secret information", then any certificate transported in 592 * the caPubs field may be directly trusted as a root CA 593 * certificate by the initiator.' 594 */ 595 switch (OSSL_CMP_MSG_get_bodytype(msg)) { 596 case -1: 597 return 0; 598 case OSSL_CMP_PKIBODY_IP: 599 case OSSL_CMP_PKIBODY_CP: 600 case OSSL_CMP_PKIBODY_KUP: 601 case OSSL_CMP_PKIBODY_CCP: 602 if (ctx->trusted != NULL) { 603 STACK_OF(X509) *certs = msg->body->value.ip->caPubs; 604 /* value.ip is same for cp, kup, and ccp */ 605 606 if (!ossl_cmp_X509_STORE_add1_certs(ctx->trusted, certs, 0)) 607 /* adds both self-issued and not self-issued certs */ 608 return 0; 609 } 610 break; 611 default: 612 break; 613 } 614 ossl_cmp_debug(ctx, 615 "successfully validated PBM-based CMP message protection"); 616 return 1; 617 } 618 ossl_cmp_warn(ctx, "verifying PBM-based CMP message protection failed"); 619 break; 620 621 /* 622 * 5.1.3.2 DH Key Pairs 623 * Not yet supported 624 */ 625 case NID_id_DHBasedMac: 626 ERR_raise(ERR_LIB_CMP, CMP_R_UNSUPPORTED_PROTECTION_ALG_DHBASEDMAC); 627 break; 628 629 /* 630 * 5.1.3.3. Signature 631 */ 632 default: 633 scrt = ctx->srvCert; 634 if (scrt == NULL) { 635 if (ctx->trusted == NULL && ctx->secretValue != NULL) { 636 ossl_cmp_info(ctx, "no trust store nor pinned server cert available for verifying signature-based CMP message protection"); 637 ERR_raise(ERR_LIB_CMP, CMP_R_MISSING_TRUST_ANCHOR); 638 return 0; 639 } 640 if (check_msg_find_cert(ctx, msg)) { 641 ossl_cmp_debug(ctx, 642 "successfully validated signature-based CMP message protection using trust store"); 643 return 1; 644 } 645 } else { /* use pinned sender cert */ 646 /* use ctx->srvCert for signature check even if not acceptable */ 647 if (verify_signature(ctx, msg, scrt)) { 648 ossl_cmp_debug(ctx, 649 "successfully validated signature-based CMP message protection using pinned server cert"); 650 return ossl_cmp_ctx_set1_validatedSrvCert(ctx, scrt); 651 } 652 ossl_cmp_warn(ctx, "CMP message signature verification failed"); 653 ERR_raise(ERR_LIB_CMP, CMP_R_SRVCERT_DOES_NOT_VALIDATE_MSG); 654 } 655 break; 656 } 657 return 0; 658 } 659 660 static int check_transactionID_or_nonce(ASN1_OCTET_STRING *expected, 661 ASN1_OCTET_STRING *actual, int reason) 662 { 663 if (expected != NULL 664 && (actual == NULL || ASN1_OCTET_STRING_cmp(expected, actual) != 0)) { 665 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 666 char *expected_str, *actual_str; 667 668 expected_str = i2s_ASN1_OCTET_STRING(NULL, expected); 669 actual_str = actual == NULL ? NULL: i2s_ASN1_OCTET_STRING(NULL, actual); 670 ERR_raise_data(ERR_LIB_CMP, reason, 671 "expected = %s, actual = %s", 672 expected_str == NULL ? "?" : expected_str, 673 actual == NULL ? "(none)" : 674 actual_str == NULL ? "?" : actual_str); 675 OPENSSL_free(expected_str); 676 OPENSSL_free(actual_str); 677 return 0; 678 #endif 679 } 680 return 1; 681 } 682 683 /*- 684 * Check received message (i.e., response by server or request from client) 685 * Any msg->extraCerts are prepended to ctx->untrusted. 686 * 687 * Ensures that: 688 * its sender is of appropriate type (currently only X509_NAME) and 689 * matches any expected sender or srvCert subject given in the ctx 690 * it has a valid body type 691 * its protection is valid (or invalid/absent, but only if a callback function 692 * is present and yields a positive result using also the supplied argument) 693 * its transaction ID matches the previous transaction ID stored in ctx (if any) 694 * its recipNonce matches the previous senderNonce stored in the ctx (if any) 695 * 696 * If everything is fine: 697 * learns the senderNonce from the received message, 698 * learns the transaction ID if it is not yet in ctx, 699 * and makes any certs in caPubs directly trusted. 700 * 701 * Returns 1 on success, 0 on error. 702 */ 703 int ossl_cmp_msg_check_update(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg, 704 ossl_cmp_allow_unprotected_cb_t cb, int cb_arg) 705 { 706 OSSL_CMP_PKIHEADER *hdr; 707 const X509_NAME *expected_sender; 708 int num_untrusted, num_added, res; 709 710 if (!ossl_assert(ctx != NULL && msg != NULL && msg->header != NULL)) 711 return 0; 712 hdr = OSSL_CMP_MSG_get0_header(msg); 713 714 /* If expected_sender is given, validate sender name of received msg */ 715 expected_sender = ctx->expected_sender; 716 if (expected_sender == NULL && ctx->srvCert != NULL) 717 expected_sender = X509_get_subject_name(ctx->srvCert); 718 if (expected_sender != NULL) { 719 const X509_NAME *actual_sender; 720 char *str; 721 722 if (hdr->sender->type != GEN_DIRNAME) { 723 ERR_raise(ERR_LIB_CMP, CMP_R_SENDER_GENERALNAME_TYPE_NOT_SUPPORTED); 724 return 0; 725 } 726 actual_sender = hdr->sender->d.directoryName; 727 /* 728 * Compare actual sender name of response with expected sender name. 729 * Mitigates risk of accepting misused PBM secret or 730 * misused certificate of an unauthorized entity of a trusted hierarchy. 731 */ 732 if (!check_name(ctx, 0, "sender DN field", actual_sender, 733 "expected sender", expected_sender)) { 734 str = X509_NAME_oneline(actual_sender, NULL, 0); 735 ERR_raise_data(ERR_LIB_CMP, CMP_R_UNEXPECTED_SENDER, 736 str != NULL ? str : "<unknown>"); 737 OPENSSL_free(str); 738 return 0; 739 } 740 } 741 /* Note: if recipient was NULL-DN it could be learned here if needed */ 742 743 num_added = sk_X509_num(msg->extraCerts); 744 if (num_added > 10) 745 ossl_cmp_log1(WARN, ctx, "received CMP message contains %d extraCerts", 746 num_added); 747 /* 748 * Store any provided extraCerts in ctx for use in OSSL_CMP_validate_msg() 749 * and for future use, such that they are available to ctx->certConf_cb and 750 * the peer does not need to send them again in the same transaction. 751 * Note that it does not help validating the message before storing the 752 * extraCerts because they do not belong to the protected msg part anyway. 753 * The extraCerts are prepended. Allows simple removal if they shall not be 754 * cached. Also they get used first, which is likely good for efficiency. 755 */ 756 num_untrusted = ctx->untrusted == NULL ? 0 : sk_X509_num(ctx->untrusted); 757 res = ossl_x509_add_certs_new(&ctx->untrusted, msg->extraCerts, 758 /* this allows self-signed certs */ 759 X509_ADD_FLAG_UP_REF | X509_ADD_FLAG_NO_DUP 760 | X509_ADD_FLAG_PREPEND); 761 num_added = (ctx->untrusted == NULL ? 0 : sk_X509_num(ctx->untrusted)) 762 - num_untrusted; 763 if (!res) { 764 while (num_added-- > 0) 765 X509_free(sk_X509_shift(ctx->untrusted)); 766 return 0; 767 } 768 769 if (hdr->protectionAlg != NULL) 770 res = OSSL_CMP_validate_msg(ctx, msg) 771 /* explicitly permitted exceptions for invalid protection: */ 772 || (cb != NULL && (*cb)(ctx, msg, 1, cb_arg) > 0); 773 else 774 /* explicitly permitted exceptions for missing protection: */ 775 res = cb != NULL && (*cb)(ctx, msg, 0, cb_arg) > 0; 776 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 777 res = 1; /* support more aggressive fuzzing by letting invalid msg pass */ 778 #endif 779 780 /* remove extraCerts again if not caching */ 781 if (ctx->noCacheExtraCerts) 782 while (num_added-- > 0) 783 X509_free(sk_X509_shift(ctx->untrusted)); 784 785 if (!res) { 786 if (hdr->protectionAlg != NULL) 787 ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_VALIDATING_PROTECTION); 788 else 789 ERR_raise(ERR_LIB_CMP, CMP_R_MISSING_PROTECTION); 790 return 0; 791 } 792 793 /* check CMP version number in header */ 794 if (ossl_cmp_hdr_get_pvno(hdr) != OSSL_CMP_PVNO_2 795 && ossl_cmp_hdr_get_pvno(hdr) != OSSL_CMP_PVNO_3) { 796 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 797 ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PVNO); 798 return 0; 799 #endif 800 } 801 802 if (OSSL_CMP_MSG_get_bodytype(msg) < 0) { 803 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 804 ERR_raise(ERR_LIB_CMP, CMP_R_PKIBODY_ERROR); 805 return 0; 806 #endif 807 } 808 809 /* compare received transactionID with the expected one in previous msg */ 810 if (!check_transactionID_or_nonce(ctx->transactionID, hdr->transactionID, 811 CMP_R_TRANSACTIONID_UNMATCHED)) 812 return 0; 813 814 /* 815 * enable clearing irrelevant errors 816 * in attempts to validate recipient nonce in case of delayed delivery. 817 */ 818 (void)ERR_set_mark(); 819 /* compare received nonce with the one we sent */ 820 if (!check_transactionID_or_nonce(ctx->senderNonce, hdr->recipNonce, 821 CMP_R_RECIPNONCE_UNMATCHED)) { 822 /* check if we are polling and received final response */ 823 if (ctx->first_senderNonce == NULL 824 || OSSL_CMP_MSG_get_bodytype(msg) == OSSL_CMP_PKIBODY_POLLREP 825 /* compare received nonce with our sender nonce at poll start */ 826 || !check_transactionID_or_nonce(ctx->first_senderNonce, 827 hdr->recipNonce, 828 CMP_R_RECIPNONCE_UNMATCHED)) { 829 (void)ERR_clear_last_mark(); 830 return 0; 831 } 832 } 833 (void)ERR_pop_to_mark(); 834 835 /* if not yet present, learn transactionID */ 836 if (ctx->transactionID == NULL 837 && !OSSL_CMP_CTX_set1_transactionID(ctx, hdr->transactionID)) 838 return 0; 839 840 /* 841 * RFC 4210 section 5.1.1 states: the recipNonce is copied from 842 * the senderNonce of the previous message in the transaction. 843 * --> Store for setting in next message 844 */ 845 if (!ossl_cmp_ctx_set1_recipNonce(ctx, hdr->senderNonce)) 846 return 0; 847 848 if (ossl_cmp_hdr_get_protection_nid(hdr) == NID_id_PasswordBasedMAC) { 849 /* 850 * RFC 4210, 5.3.2: 'Note that if the PKI Message Protection is 851 * "shared secret information", then any certificate transported in 852 * the caPubs field may be directly trusted as a root CA 853 * certificate by the initiator.' 854 */ 855 switch (OSSL_CMP_MSG_get_bodytype(msg)) { 856 case OSSL_CMP_PKIBODY_IP: 857 case OSSL_CMP_PKIBODY_CP: 858 case OSSL_CMP_PKIBODY_KUP: 859 case OSSL_CMP_PKIBODY_CCP: 860 if (ctx->trusted != NULL) { 861 STACK_OF(X509) *certs = msg->body->value.ip->caPubs; 862 /* value.ip is same for cp, kup, and ccp */ 863 864 if (!ossl_cmp_X509_STORE_add1_certs(ctx->trusted, certs, 0)) 865 /* adds both self-issued and not self-issued certs */ 866 return 0; 867 } 868 break; 869 default: 870 break; 871 } 872 } 873 return 1; 874 } 875 876 int ossl_cmp_verify_popo(const OSSL_CMP_CTX *ctx, 877 const OSSL_CMP_MSG *msg, int acceptRAVerified) 878 { 879 if (!ossl_assert(msg != NULL && msg->body != NULL)) 880 return 0; 881 switch (msg->body->type) { 882 case OSSL_CMP_PKIBODY_P10CR: 883 { 884 X509_REQ *req = msg->body->value.p10cr; 885 886 if (X509_REQ_verify_ex(req, X509_REQ_get0_pubkey(req), ctx->libctx, 887 ctx->propq) <= 0) { 888 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 889 ERR_raise(ERR_LIB_CMP, CMP_R_REQUEST_NOT_ACCEPTED); 890 return 0; 891 #endif 892 } 893 } 894 break; 895 case OSSL_CMP_PKIBODY_IR: 896 case OSSL_CMP_PKIBODY_CR: 897 case OSSL_CMP_PKIBODY_KUR: 898 if (!OSSL_CRMF_MSGS_verify_popo(msg->body->value.ir, OSSL_CMP_CERTREQID, 899 acceptRAVerified, 900 ctx->libctx, ctx->propq)) { 901 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION 902 return 0; 903 #endif 904 } 905 break; 906 default: 907 ERR_raise(ERR_LIB_CMP, CMP_R_PKIBODY_ERROR); 908 return 0; 909 } 910 return 1; 911 } 912