| /* |
| * Copyright 2001-2022 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the Apache License 2.0 (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| #include <string.h> |
| #include <openssl/ocsp.h> |
| #include <openssl/err.h> |
| #include "internal/sizes.h" |
| #include "ocsp_local.h" |
| |
| static int ocsp_find_signer(X509 **psigner, OCSP_BASICRESP *bs, |
| STACK_OF(X509) *certs, unsigned long flags); |
| static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id); |
| static int ocsp_check_issuer(OCSP_BASICRESP *bs, STACK_OF(X509) *chain); |
| static int ocsp_check_ids(STACK_OF(OCSP_SINGLERESP) *sresp, |
| OCSP_CERTID **ret); |
| static int ocsp_match_issuerid(X509 *cert, OCSP_CERTID *cid, |
| STACK_OF(OCSP_SINGLERESP) *sresp); |
| static int ocsp_check_delegated(X509 *x); |
| static int ocsp_req_find_signer(X509 **psigner, OCSP_REQUEST *req, |
| const X509_NAME *nm, STACK_OF(X509) *certs, |
| unsigned long flags); |
| |
| /* Returns 1 on success, 0 on failure, or -1 on fatal error */ |
| static int ocsp_verify_signer(X509 *signer, int response, |
| X509_STORE *st, unsigned long flags, |
| STACK_OF(X509) *untrusted, STACK_OF(X509) **chain) |
| { |
| X509_STORE_CTX *ctx = X509_STORE_CTX_new(); |
| X509_VERIFY_PARAM *vp; |
| int ret = -1; |
| |
| if (ctx == NULL) { |
| ERR_raise(ERR_LIB_OCSP, ERR_R_MALLOC_FAILURE); |
| goto end; |
| } |
| if (!X509_STORE_CTX_init(ctx, st, signer, untrusted)) { |
| ERR_raise(ERR_LIB_OCSP, ERR_R_X509_LIB); |
| goto end; |
| } |
| if ((vp = X509_STORE_CTX_get0_param(ctx)) == NULL) |
| goto end; |
| if ((flags & OCSP_PARTIAL_CHAIN) != 0) |
| X509_VERIFY_PARAM_set_flags(vp, X509_V_FLAG_PARTIAL_CHAIN); |
| if (response |
| && X509_get_ext_by_NID(signer, NID_id_pkix_OCSP_noCheck, -1) >= 0) |
| /* |
| * Locally disable revocation status checking for OCSP responder cert. |
| * Done here for CRLs; should be done also for OCSP-based checks. |
| */ |
| X509_VERIFY_PARAM_clear_flags(vp, X509_V_FLAG_CRL_CHECK); |
| X509_STORE_CTX_set_purpose(ctx, X509_PURPOSE_OCSP_HELPER); |
| X509_STORE_CTX_set_trust(ctx, X509_TRUST_OCSP_REQUEST); |
| |
| ret = X509_verify_cert(ctx); |
| if (ret <= 0) { |
| int err = X509_STORE_CTX_get_error(ctx); |
| |
| ERR_raise_data(ERR_LIB_OCSP, OCSP_R_CERTIFICATE_VERIFY_ERROR, |
| "Verify error: %s", X509_verify_cert_error_string(err)); |
| goto end; |
| } |
| if (chain != NULL) |
| *chain = X509_STORE_CTX_get1_chain(ctx); |
| |
| end: |
| X509_STORE_CTX_free(ctx); |
| return ret; |
| } |
| |
| static int ocsp_verify(OCSP_REQUEST *req, OCSP_BASICRESP *bs, |
| X509 *signer, unsigned long flags) |
| { |
| EVP_PKEY *skey; |
| int ret = 1; |
| |
| if ((flags & OCSP_NOSIGS) == 0) { |
| if ((skey = X509_get0_pubkey(signer)) == NULL) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_NO_SIGNER_KEY); |
| return -1; |
| } |
| if (req != NULL) |
| ret = OCSP_REQUEST_verify(req, skey, signer->libctx, signer->propq); |
| else |
| ret = OCSP_BASICRESP_verify(bs, skey, signer->libctx, signer->propq); |
| if (ret <= 0) |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_SIGNATURE_FAILURE); |
| } |
| return ret; |
| } |
| |
| /* Verify a basic response message */ |
| int OCSP_basic_verify(OCSP_BASICRESP *bs, STACK_OF(X509) *certs, |
| X509_STORE *st, unsigned long flags) |
| { |
| X509 *signer, *x; |
| STACK_OF(X509) *chain = NULL; |
| STACK_OF(X509) *untrusted = NULL; |
| int ret = ocsp_find_signer(&signer, bs, certs, flags); |
| |
| if (ret == 0) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_SIGNER_CERTIFICATE_NOT_FOUND); |
| goto end; |
| } |
| if ((ret == 2) && (flags & OCSP_TRUSTOTHER) != 0) |
| flags |= OCSP_NOVERIFY; |
| |
| if ((ret = ocsp_verify(NULL, bs, signer, flags)) <= 0) |
| goto end; |
| if ((flags & OCSP_NOVERIFY) == 0) { |
| ret = -1; |
| if ((flags & OCSP_NOCHAIN) == 0) { |
| if ((untrusted = sk_X509_dup(bs->certs)) == NULL) |
| goto end; |
| if (!X509_add_certs(untrusted, certs, X509_ADD_FLAG_DEFAULT)) |
| goto end; |
| } |
| ret = ocsp_verify_signer(signer, 1, st, flags, untrusted, &chain); |
| if (ret <= 0) |
| goto end; |
| if ((flags & OCSP_NOCHECKS) != 0) { |
| ret = 1; |
| goto end; |
| } |
| /* |
| * At this point we have a valid certificate chain need to verify it |
| * against the OCSP issuer criteria. |
| */ |
| ret = ocsp_check_issuer(bs, chain); |
| |
| /* If fatal error or valid match then finish */ |
| if (ret != 0) |
| goto end; |
| |
| /* |
| * Easy case: explicitly trusted. Get root CA and check for explicit |
| * trust |
| */ |
| if ((flags & OCSP_NOEXPLICIT) != 0) |
| goto end; |
| |
| x = sk_X509_value(chain, sk_X509_num(chain) - 1); |
| if (X509_check_trust(x, NID_OCSP_sign, 0) != X509_TRUST_TRUSTED) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_ROOT_CA_NOT_TRUSTED); |
| ret = 0; |
| goto end; |
| } |
| ret = 1; |
| } |
| |
| end: |
| OSSL_STACK_OF_X509_free(chain); |
| sk_X509_free(untrusted); |
| return ret; |
| } |
| |
| int OCSP_resp_get0_signer(OCSP_BASICRESP *bs, X509 **signer, |
| STACK_OF(X509) *extra_certs) |
| { |
| return ocsp_find_signer(signer, bs, extra_certs, 0) > 0; |
| } |
| |
| static int ocsp_find_signer(X509 **psigner, OCSP_BASICRESP *bs, |
| STACK_OF(X509) *certs, unsigned long flags) |
| { |
| X509 *signer; |
| OCSP_RESPID *rid = &bs->tbsResponseData.responderId; |
| |
| if ((signer = ocsp_find_signer_sk(certs, rid)) != NULL) { |
| *psigner = signer; |
| return 2; |
| } |
| if ((flags & OCSP_NOINTERN) == 0 && |
| (signer = ocsp_find_signer_sk(bs->certs, rid))) { |
| *psigner = signer; |
| return 1; |
| } |
| /* Maybe lookup from store if by subject name */ |
| |
| *psigner = NULL; |
| return 0; |
| } |
| |
| static X509 *ocsp_find_signer_sk(STACK_OF(X509) *certs, OCSP_RESPID *id) |
| { |
| int i, r; |
| unsigned char tmphash[SHA_DIGEST_LENGTH], *keyhash; |
| EVP_MD *md; |
| X509 *x; |
| |
| /* Easy if lookup by name */ |
| if (id->type == V_OCSP_RESPID_NAME) |
| return X509_find_by_subject(certs, id->value.byName); |
| |
| /* Lookup by key hash */ |
| |
| /* If key hash isn't SHA1 length then forget it */ |
| if (id->value.byKey->length != SHA_DIGEST_LENGTH) |
| return NULL; |
| keyhash = id->value.byKey->data; |
| /* Calculate hash of each key and compare */ |
| for (i = 0; i < sk_X509_num(certs); i++) { |
| if ((x = sk_X509_value(certs, i)) != NULL) { |
| if ((md = EVP_MD_fetch(x->libctx, SN_sha1, x->propq)) == NULL) |
| break; |
| r = X509_pubkey_digest(x, md, tmphash, NULL); |
| EVP_MD_free(md); |
| if (!r) |
| break; |
| if (memcmp(keyhash, tmphash, SHA_DIGEST_LENGTH) == 0) |
| return x; |
| } |
| } |
| return NULL; |
| } |
| |
| static int ocsp_check_issuer(OCSP_BASICRESP *bs, STACK_OF(X509) *chain) |
| { |
| STACK_OF(OCSP_SINGLERESP) *sresp = bs->tbsResponseData.responses; |
| X509 *signer, *sca; |
| OCSP_CERTID *caid = NULL; |
| int ret; |
| |
| if (sk_X509_num(chain) <= 0) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_NO_CERTIFICATES_IN_CHAIN); |
| return -1; |
| } |
| |
| /* See if the issuer IDs match. */ |
| ret = ocsp_check_ids(sresp, &caid); |
| |
| /* If ID mismatch or other error then return */ |
| if (ret <= 0) |
| return ret; |
| |
| signer = sk_X509_value(chain, 0); |
| /* Check to see if OCSP responder CA matches request CA */ |
| if (sk_X509_num(chain) > 1) { |
| sca = sk_X509_value(chain, 1); |
| ret = ocsp_match_issuerid(sca, caid, sresp); |
| if (ret < 0) |
| return ret; |
| if (ret != 0) { |
| /* We have a match, if extensions OK then success */ |
| if (ocsp_check_delegated(signer)) |
| return 1; |
| return 0; |
| } |
| } |
| |
| /* Otherwise check if OCSP request signed directly by request CA */ |
| return ocsp_match_issuerid(signer, caid, sresp); |
| } |
| |
| /* |
| * Check the issuer certificate IDs for equality. If there is a mismatch with |
| * the same algorithm then there's no point trying to match any certificates |
| * against the issuer. If the issuer IDs all match then we just need to check |
| * equality against one of them. |
| */ |
| |
| static int ocsp_check_ids(STACK_OF(OCSP_SINGLERESP) *sresp, OCSP_CERTID **ret) |
| { |
| OCSP_CERTID *tmpid, *cid; |
| int i, idcount; |
| |
| idcount = sk_OCSP_SINGLERESP_num(sresp); |
| if (idcount <= 0) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_RESPONSE_CONTAINS_NO_REVOCATION_DATA); |
| return -1; |
| } |
| |
| cid = sk_OCSP_SINGLERESP_value(sresp, 0)->certId; |
| |
| *ret = NULL; |
| for (i = 1; i < idcount; i++) { |
| tmpid = sk_OCSP_SINGLERESP_value(sresp, i)->certId; |
| /* Check to see if IDs match */ |
| if (OCSP_id_issuer_cmp(cid, tmpid)) { |
| /* If algorithm mismatch let caller deal with it */ |
| if (OBJ_cmp(tmpid->hashAlgorithm.algorithm, |
| cid->hashAlgorithm.algorithm)) |
| return 2; |
| /* Else mismatch */ |
| return 0; |
| } |
| } |
| |
| /* All IDs match: only need to check one ID */ |
| *ret = cid; |
| return 1; |
| } |
| |
| /* |
| * Match the certificate issuer ID. |
| * Returns -1 on fatal error, 0 if there is no match and 1 if there is a match. |
| */ |
| static int ocsp_match_issuerid(X509 *cert, OCSP_CERTID *cid, |
| STACK_OF(OCSP_SINGLERESP) *sresp) |
| { |
| int ret = -1; |
| EVP_MD *dgst = NULL; |
| |
| /* If only one ID to match then do it */ |
| if (cid != NULL) { |
| char name[OSSL_MAX_NAME_SIZE]; |
| const X509_NAME *iname; |
| int mdlen; |
| unsigned char md[EVP_MAX_MD_SIZE]; |
| |
| OBJ_obj2txt(name, sizeof(name), cid->hashAlgorithm.algorithm, 0); |
| |
| (void)ERR_set_mark(); |
| dgst = EVP_MD_fetch(NULL, name, NULL); |
| if (dgst == NULL) |
| dgst = (EVP_MD *)EVP_get_digestbyname(name); |
| |
| if (dgst == NULL) { |
| (void)ERR_clear_last_mark(); |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_UNKNOWN_MESSAGE_DIGEST); |
| goto end; |
| } |
| (void)ERR_pop_to_mark(); |
| |
| mdlen = EVP_MD_get_size(dgst); |
| if (mdlen < 0) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_DIGEST_SIZE_ERR); |
| goto end; |
| } |
| if (cid->issuerNameHash.length != mdlen || |
| cid->issuerKeyHash.length != mdlen) { |
| ret = 0; |
| goto end; |
| } |
| iname = X509_get_subject_name(cert); |
| if (!X509_NAME_digest(iname, dgst, md, NULL)) |
| goto end; |
| if (memcmp(md, cid->issuerNameHash.data, mdlen) != 0) { |
| ret = 0; |
| goto end; |
| } |
| if (!X509_pubkey_digest(cert, dgst, md, NULL)) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_DIGEST_ERR); |
| goto end; |
| } |
| ret = memcmp(md, cid->issuerKeyHash.data, mdlen) == 0; |
| goto end; |
| } else { |
| /* We have to match the whole lot */ |
| int i; |
| OCSP_CERTID *tmpid; |
| |
| for (i = 0; i < sk_OCSP_SINGLERESP_num(sresp); i++) { |
| tmpid = sk_OCSP_SINGLERESP_value(sresp, i)->certId; |
| ret = ocsp_match_issuerid(cert, tmpid, NULL); |
| if (ret <= 0) |
| return ret; |
| } |
| } |
| return 1; |
| end: |
| EVP_MD_free(dgst); |
| return ret; |
| } |
| |
| static int ocsp_check_delegated(X509 *x) |
| { |
| if ((X509_get_extension_flags(x) & EXFLAG_XKUSAGE) |
| && (X509_get_extended_key_usage(x) & XKU_OCSP_SIGN)) |
| return 1; |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_MISSING_OCSPSIGNING_USAGE); |
| return 0; |
| } |
| |
| /* |
| * Verify an OCSP request. This is much easier than OCSP response verify. |
| * Just find the signer's certificate and verify it against a given trust value. |
| * Returns 1 on success, 0 on failure and on fatal error. |
| */ |
| int OCSP_request_verify(OCSP_REQUEST *req, STACK_OF(X509) *certs, |
| X509_STORE *store, unsigned long flags) |
| { |
| X509 *signer; |
| const X509_NAME *nm; |
| GENERAL_NAME *gen; |
| int ret; |
| |
| if (!req->optionalSignature) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_REQUEST_NOT_SIGNED); |
| return 0; |
| } |
| gen = req->tbsRequest.requestorName; |
| if (!gen || gen->type != GEN_DIRNAME) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_UNSUPPORTED_REQUESTORNAME_TYPE); |
| return 0; /* not returning -1 here for backward compatibility*/ |
| } |
| nm = gen->d.directoryName; |
| ret = ocsp_req_find_signer(&signer, req, nm, certs, flags); |
| if (ret <= 0) { |
| ERR_raise(ERR_LIB_OCSP, OCSP_R_SIGNER_CERTIFICATE_NOT_FOUND); |
| return 0; /* not returning -1 here for backward compatibility*/ |
| } |
| if ((ret == 2) && (flags & OCSP_TRUSTOTHER) != 0) |
| flags |= OCSP_NOVERIFY; |
| |
| if ((ret = ocsp_verify(req, NULL, signer, flags)) <= 0) |
| return 0; /* not returning 'ret' here for backward compatibility*/ |
| if ((flags & OCSP_NOVERIFY) != 0) |
| return 1; |
| return ocsp_verify_signer(signer, 0, store, flags, |
| (flags & OCSP_NOCHAIN) != 0 ? |
| NULL : req->optionalSignature->certs, NULL) > 0; |
| /* using '> 0' here to avoid breaking backward compatibility returning -1 */ |
| } |
| |
| static int ocsp_req_find_signer(X509 **psigner, OCSP_REQUEST *req, |
| const X509_NAME *nm, STACK_OF(X509) *certs, |
| unsigned long flags) |
| { |
| X509 *signer; |
| |
| if ((flags & OCSP_NOINTERN) == 0) { |
| signer = X509_find_by_subject(req->optionalSignature->certs, nm); |
| if (signer != NULL) { |
| *psigner = signer; |
| return 1; |
| } |
| } |
| |
| if ((signer = X509_find_by_subject(certs, nm)) != NULL) { |
| *psigner = signer; |
| return 2; |
| } |
| return 0; |
| } |
