/* $OpenBSD: x509_purp.c,v 1.43 2024/07/12 18:15:10 beck Exp $ */ /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL * project 2001. */ /* ==================================================================== * Copyright (c) 1999-2004 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * licensing@OpenSSL.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #include #include #include #include #include #include #include "x509_internal.h" #include "x509_local.h" struct x509_purpose_st { int purpose; int trust; /* Default trust ID */ int flags; int (*check_purpose)(const struct x509_purpose_st *, const X509 *, int); char *name; char *sname; void *usr_data; } /* X509_PURPOSE */; #define V1_ROOT (EXFLAG_V1|EXFLAG_SS) #define ku_reject(x, usage) \ (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage))) #define xku_reject(x, usage) \ (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage))) #define ns_reject(x, usage) \ (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage))) static int check_ssl_ca(const X509 *x); static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca); static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca); static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca); static int purpose_smime(const X509 *x, int ca); static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca); static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca); static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca); static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca); static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca); static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca); static const X509_PURPOSE xstandard[] = { { .purpose = X509_PURPOSE_SSL_CLIENT, .trust = X509_TRUST_SSL_CLIENT, .check_purpose = check_purpose_ssl_client, .name = "SSL client", .sname = "sslclient", }, { .purpose = X509_PURPOSE_SSL_SERVER, .trust = X509_TRUST_SSL_SERVER, .check_purpose = check_purpose_ssl_server, .name = "SSL server", .sname = "sslserver", }, { .purpose = X509_PURPOSE_NS_SSL_SERVER, .trust = X509_TRUST_SSL_SERVER, .check_purpose = check_purpose_ns_ssl_server, .name = "Netscape SSL server", .sname = "nssslserver", }, { .purpose = X509_PURPOSE_SMIME_SIGN, .trust = X509_TRUST_EMAIL, .check_purpose = check_purpose_smime_sign, .name = "S/MIME signing", .sname = "smimesign", }, { .purpose = X509_PURPOSE_SMIME_ENCRYPT, .trust = X509_TRUST_EMAIL, .check_purpose = check_purpose_smime_encrypt, .name = "S/MIME encryption", .sname = "smimeencrypt", }, { .purpose = X509_PURPOSE_CRL_SIGN, .trust = X509_TRUST_COMPAT, .check_purpose = check_purpose_crl_sign, .name = "CRL signing", .sname = "crlsign", }, { .purpose = X509_PURPOSE_ANY, .trust = X509_TRUST_ACCEPT_ALL, .check_purpose = no_check, .name = "Any Purpose", .sname = "any", }, { .purpose = X509_PURPOSE_OCSP_HELPER, .trust = X509_TRUST_COMPAT, .check_purpose = ocsp_helper, .name = "OCSP helper", .sname = "ocsphelper", }, { .purpose = X509_PURPOSE_TIMESTAMP_SIGN, .trust = X509_TRUST_TSA, .check_purpose = check_purpose_timestamp_sign, .name = "Time Stamp signing", .sname = "timestampsign", }, }; #define X509_PURPOSE_COUNT (sizeof(xstandard) / sizeof(xstandard[0])) /* As much as I'd like to make X509_check_purpose use a "const" X509* * I really can't because it does recalculate hashes and do other non-const * things. */ int X509_check_purpose(X509 *x, int id, int ca) { int idx; const X509_PURPOSE *pt; if (!x509v3_cache_extensions(x)) return -1; if (id == -1) return 1; if ((idx = X509_PURPOSE_get_by_id(id)) == -1) return -1; if ((pt = X509_PURPOSE_get0(idx)) == NULL) return -1; return pt->check_purpose(pt, x, ca); } LCRYPTO_ALIAS(X509_check_purpose); int X509_PURPOSE_get_count(void) { return X509_PURPOSE_COUNT; } LCRYPTO_ALIAS(X509_PURPOSE_get_count); const X509_PURPOSE * X509_PURPOSE_get0(int idx) { if (idx < 0 || (size_t)idx >= X509_PURPOSE_COUNT) return NULL; return &xstandard[idx]; } LCRYPTO_ALIAS(X509_PURPOSE_get0); int X509_PURPOSE_get_by_sname(const char *sname) { int i; const X509_PURPOSE *xptmp; for (i = 0; i < X509_PURPOSE_get_count(); i++) { xptmp = X509_PURPOSE_get0(i); if (!strcmp(xptmp->sname, sname)) return i; } return -1; } LCRYPTO_ALIAS(X509_PURPOSE_get_by_sname); int X509_PURPOSE_get_by_id(int purpose) { /* * Ensure the purpose identifier is between MIN and MAX inclusive. * If so, translate it to an index into the xstandard[] table. */ if (purpose < X509_PURPOSE_MIN || purpose > X509_PURPOSE_MAX) return -1; return purpose - X509_PURPOSE_MIN; } int X509_PURPOSE_get_id(const X509_PURPOSE *xp) { return xp->purpose; } LCRYPTO_ALIAS(X509_PURPOSE_get_id); const char * X509_PURPOSE_get0_name(const X509_PURPOSE *xp) { return xp->name; } LCRYPTO_ALIAS(X509_PURPOSE_get0_name); const char * X509_PURPOSE_get0_sname(const X509_PURPOSE *xp) { return xp->sname; } LCRYPTO_ALIAS(X509_PURPOSE_get0_sname); int X509_PURPOSE_get_trust(const X509_PURPOSE *xp) { return xp->trust; } /* * List of NIDs of extensions supported by the verifier. If an extension * is critical and doesn't appear in this list, then the certificate will * normally be rejected. */ int X509_supported_extension(X509_EXTENSION *ext) { switch (OBJ_obj2nid(X509_EXTENSION_get_object(ext))) { case NID_basic_constraints: case NID_certificate_policies: case NID_ext_key_usage: case NID_inhibit_any_policy: case NID_key_usage: case NID_name_constraints: case NID_netscape_cert_type: case NID_policy_constraints: case NID_policy_mappings: #ifndef OPENSSL_NO_RFC3779 case NID_sbgp_ipAddrBlock: case NID_sbgp_autonomousSysNum: #endif case NID_subject_alt_name: return 1; default: return 0; } } LCRYPTO_ALIAS(X509_supported_extension); static void setup_dp(X509 *x, DIST_POINT *dp) { X509_NAME *iname = NULL; int i; if (dp->reasons) { if (dp->reasons->length > 0) dp->dp_reasons = dp->reasons->data[0]; if (dp->reasons->length > 1) dp->dp_reasons |= (dp->reasons->data[1] << 8); dp->dp_reasons &= CRLDP_ALL_REASONS; } else dp->dp_reasons = CRLDP_ALL_REASONS; if (!dp->distpoint || (dp->distpoint->type != 1)) return; for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); if (gen->type == GEN_DIRNAME) { iname = gen->d.directoryName; break; } } if (!iname) iname = X509_get_issuer_name(x); DIST_POINT_set_dpname(dp->distpoint, iname); } static void setup_crldp(X509 *x) { int i; x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL); if (x->crldp == NULL && i != -1) { x->ex_flags |= EXFLAG_INVALID; return; } for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) setup_dp(x, sk_DIST_POINT_value(x->crldp, i)); } static int x509_extension_oid_cmp(const X509_EXTENSION *const *a, const X509_EXTENSION *const *b) { return OBJ_cmp((*a)->object, (*b)->object); } static int x509_extension_oids_are_unique(X509 *x509) { STACK_OF(X509_EXTENSION) *exts = NULL; const X509_EXTENSION *prev_ext, *curr_ext; int i; int ret = 0; if (X509_get_ext_count(x509) <= 1) goto done; if ((exts = sk_X509_EXTENSION_dup(x509->cert_info->extensions)) == NULL) goto err; (void)sk_X509_EXTENSION_set_cmp_func(exts, x509_extension_oid_cmp); sk_X509_EXTENSION_sort(exts); prev_ext = sk_X509_EXTENSION_value(exts, 0); for (i = 1; i < sk_X509_EXTENSION_num(exts); i++) { curr_ext = sk_X509_EXTENSION_value(exts, i); if (x509_extension_oid_cmp(&prev_ext, &curr_ext) == 0) goto err; prev_ext = curr_ext; } done: ret = 1; err: sk_X509_EXTENSION_free(exts); return ret; } static void x509v3_cache_extensions_internal(X509 *x) { BASIC_CONSTRAINTS *bs; ASN1_BIT_STRING *usage; ASN1_BIT_STRING *ns; EXTENDED_KEY_USAGE *extusage; X509_EXTENSION *ex; long version; int i; if (x->ex_flags & EXFLAG_SET) return; /* * XXX - this should really only set EXFLAG_INVALID if extensions are * invalid. However, the X509_digest() failure matches OpenSSL/BoringSSL * behavior and the version checks are at least vaguely related to * extensions. */ if (!X509_digest(x, X509_CERT_HASH_EVP, x->hash, NULL)) x->ex_flags |= EXFLAG_INVALID; version = X509_get_version(x); if (version < 0 || version > 2) x->ex_flags |= EXFLAG_INVALID; if (version == 0) { x->ex_flags |= EXFLAG_V1; /* UIDs may only appear in v2 or v3 certs */ if (x->cert_info->issuerUID != NULL || x->cert_info->subjectUID != NULL) x->ex_flags |= EXFLAG_INVALID; } if (version != 2 && X509_get_ext_count(x) != 0) x->ex_flags |= EXFLAG_INVALID; /* Handle basic constraints */ if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL))) { if (bs->ca) x->ex_flags |= EXFLAG_CA; if (bs->pathlen) { if ((bs->pathlen->type == V_ASN1_NEG_INTEGER) || !bs->ca) { x->ex_flags |= EXFLAG_INVALID; x->ex_pathlen = 0; } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen); } else x->ex_pathlen = -1; BASIC_CONSTRAINTS_free(bs); x->ex_flags |= EXFLAG_BCONS; } else if (i != -1) { x->ex_flags |= EXFLAG_INVALID; } /* Handle key usage */ if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL))) { if (usage->length > 0) { x->ex_kusage = usage->data[0]; if (usage->length > 1) x->ex_kusage |= usage->data[1] << 8; } else x->ex_kusage = 0; x->ex_flags |= EXFLAG_KUSAGE; ASN1_BIT_STRING_free(usage); } else if (i != -1) { x->ex_flags |= EXFLAG_INVALID; } x->ex_xkusage = 0; if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL))) { x->ex_flags |= EXFLAG_XKUSAGE; for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) { switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) { case NID_server_auth: x->ex_xkusage |= XKU_SSL_SERVER; break; case NID_client_auth: x->ex_xkusage |= XKU_SSL_CLIENT; break; case NID_email_protect: x->ex_xkusage |= XKU_SMIME; break; case NID_code_sign: x->ex_xkusage |= XKU_CODE_SIGN; break; case NID_ms_sgc: case NID_ns_sgc: x->ex_xkusage |= XKU_SGC; break; case NID_OCSP_sign: x->ex_xkusage |= XKU_OCSP_SIGN; break; case NID_time_stamp: x->ex_xkusage |= XKU_TIMESTAMP; break; case NID_dvcs: x->ex_xkusage |= XKU_DVCS; break; case NID_anyExtendedKeyUsage: x->ex_xkusage |= XKU_ANYEKU; break; } } sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free); } else if (i != -1) { x->ex_flags |= EXFLAG_INVALID; } if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL))) { if (ns->length > 0) x->ex_nscert = ns->data[0]; else x->ex_nscert = 0; x->ex_flags |= EXFLAG_NSCERT; ASN1_BIT_STRING_free(ns); } else if (i != -1) { x->ex_flags |= EXFLAG_INVALID; } x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL); if (x->skid == NULL && i != -1) x->ex_flags |= EXFLAG_INVALID; x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL); if (x->akid == NULL && i != -1) x->ex_flags |= EXFLAG_INVALID; /* Does subject name match issuer? */ if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) { x->ex_flags |= EXFLAG_SI; /* If SKID matches AKID also indicate self signed. */ if (X509_check_akid(x, x->akid) == X509_V_OK && !ku_reject(x, KU_KEY_CERT_SIGN)) x->ex_flags |= EXFLAG_SS; } x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL); if (x->altname == NULL && i != -1) x->ex_flags |= EXFLAG_INVALID; x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL); if (!x->nc && (i != -1)) x->ex_flags |= EXFLAG_INVALID; setup_crldp(x); #ifndef OPENSSL_NO_RFC3779 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL); if (x->rfc3779_addr == NULL && i != -1) x->ex_flags |= EXFLAG_INVALID; if (!X509v3_addr_is_canonical(x->rfc3779_addr)) x->ex_flags |= EXFLAG_INVALID; x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL); if (x->rfc3779_asid == NULL && i != -1) x->ex_flags |= EXFLAG_INVALID; if (!X509v3_asid_is_canonical(x->rfc3779_asid)) x->ex_flags |= EXFLAG_INVALID; #endif for (i = 0; i < X509_get_ext_count(x); i++) { ex = X509_get_ext(x, i); if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) == NID_freshest_crl) x->ex_flags |= EXFLAG_FRESHEST; if (!X509_EXTENSION_get_critical(ex)) continue; if (!X509_supported_extension(ex)) { x->ex_flags |= EXFLAG_CRITICAL; break; } } if (!x509_extension_oids_are_unique(x)) x->ex_flags |= EXFLAG_INVALID; x->ex_flags |= EXFLAG_SET; } int x509v3_cache_extensions(X509 *x) { if ((x->ex_flags & EXFLAG_SET) == 0) { CRYPTO_w_lock(CRYPTO_LOCK_X509); x509v3_cache_extensions_internal(x); CRYPTO_w_unlock(CRYPTO_LOCK_X509); } return (x->ex_flags & EXFLAG_INVALID) == 0; } /* CA checks common to all purposes * return codes: * 0 not a CA * 1 is a CA * 2 basicConstraints absent so "maybe" a CA * 3 basicConstraints absent but self signed V1. * 4 basicConstraints absent but keyUsage present and keyCertSign asserted. */ static int check_ca(const X509 *x) { /* keyUsage if present should allow cert signing */ if (ku_reject(x, KU_KEY_CERT_SIGN)) return 0; if (x->ex_flags & EXFLAG_BCONS) { if (x->ex_flags & EXFLAG_CA) return 1; /* If basicConstraints says not a CA then say so */ else return 0; } else { /* we support V1 roots for... uh, I don't really know why. */ if ((x->ex_flags & V1_ROOT) == V1_ROOT) return 3; /* If key usage present it must have certSign so tolerate it */ else if (x->ex_flags & EXFLAG_KUSAGE) return 4; /* Older certificates could have Netscape-specific CA types */ else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA) return 5; /* can this still be regarded a CA certificate? I doubt it */ return 0; } } int X509_check_ca(X509 *x) { x509v3_cache_extensions(x); return check_ca(x); } LCRYPTO_ALIAS(X509_check_ca); /* Check SSL CA: common checks for SSL client and server */ static int check_ssl_ca(const X509 *x) { int ca_ret; ca_ret = check_ca(x); if (!ca_ret) return 0; /* check nsCertType if present */ if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret; else return 0; } static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca) { if (xku_reject(x, XKU_SSL_CLIENT)) return 0; if (ca) return check_ssl_ca(x); /* We need to do digital signatures with it */ if (ku_reject(x, KU_DIGITAL_SIGNATURE)) return 0; /* nsCertType if present should allow SSL client use */ if (ns_reject(x, NS_SSL_CLIENT)) return 0; return 1; } static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) { if (xku_reject(x, XKU_SSL_SERVER|XKU_SGC)) return 0; if (ca) return check_ssl_ca(x); if (ns_reject(x, NS_SSL_SERVER)) return 0; /* Now as for keyUsage: we'll at least need to sign OR encipher */ if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0; return 1; } static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) { int ret; ret = check_purpose_ssl_server(xp, x, ca); if (!ret || ca) return ret; /* We need to encipher or Netscape complains */ if (ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0; return ret; } /* common S/MIME checks */ static int purpose_smime(const X509 *x, int ca) { if (xku_reject(x, XKU_SMIME)) return 0; if (ca) { int ca_ret; ca_ret = check_ca(x); if (!ca_ret) return 0; /* check nsCertType if present */ if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret; else return 0; } if (x->ex_flags & EXFLAG_NSCERT) { if (x->ex_nscert & NS_SMIME) return 1; /* Workaround for some buggy certificates */ if (x->ex_nscert & NS_SSL_CLIENT) return 2; return 0; } return 1; } static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca) { int ret; ret = purpose_smime(x, ca); if (!ret || ca) return ret; if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0; return ret; } static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca) { int ret; ret = purpose_smime(x, ca); if (!ret || ca) return ret; if (ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0; return ret; } static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca) { if (ca) { int ca_ret; if ((ca_ret = check_ca(x)) != 2) return ca_ret; else return 0; } if (ku_reject(x, KU_CRL_SIGN)) return 0; return 1; } /* OCSP helper: this is *not* a full OCSP check. It just checks that * each CA is valid. Additional checks must be made on the chain. */ static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca) { /* Must be a valid CA. Should we really support the "I don't know" value (2)? */ if (ca) return check_ca(x); /* leaf certificate is checked in OCSP_verify() */ return 1; } static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca) { int i_ext; /* If ca is true we must return if this is a valid CA certificate. */ if (ca) return check_ca(x); /* * Check the optional key usage field: * if Key Usage is present, it must be one of digitalSignature * and/or nonRepudiation (other values are not consistent and shall * be rejected). */ if ((x->ex_flags & EXFLAG_KUSAGE) && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) || !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)))) return 0; /* Only time stamp key usage is permitted and it's required. */ if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP) return 0; /* Extended Key Usage MUST be critical */ i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, -1); if (i_ext >= 0) { X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext); if (!X509_EXTENSION_get_critical(ext)) return 0; } return 1; } static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca) { return 1; } /* Various checks to see if one certificate issued the second. * This can be used to prune a set of possible issuer certificates * which have been looked up using some simple method such as by * subject name. * These are: * 1. Check issuer_name(subject) == subject_name(issuer) * 2. If akid(subject) exists check it matches issuer * 3. If key_usage(issuer) exists check it supports certificate signing * returns 0 for OK, positive for reason for mismatch, reasons match * codes for X509_verify_cert() */ int X509_check_issued(X509 *issuer, X509 *subject) { if (X509_NAME_cmp(X509_get_subject_name(issuer), X509_get_issuer_name(subject))) return X509_V_ERR_SUBJECT_ISSUER_MISMATCH; if (!x509v3_cache_extensions(issuer)) return X509_V_ERR_UNSPECIFIED; if (!x509v3_cache_extensions(subject)) return X509_V_ERR_UNSPECIFIED; if (subject->akid) { int ret = X509_check_akid(issuer, subject->akid); if (ret != X509_V_OK) return ret; } if (ku_reject(issuer, KU_KEY_CERT_SIGN)) return X509_V_ERR_KEYUSAGE_NO_CERTSIGN; return X509_V_OK; } LCRYPTO_ALIAS(X509_check_issued); int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid) { if (!akid) return X509_V_OK; /* Check key ids (if present) */ if (akid->keyid && issuer->skid && ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid)) return X509_V_ERR_AKID_SKID_MISMATCH; /* Check serial number */ if (akid->serial && ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial)) return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; /* Check issuer name */ if (akid->issuer) { /* Ugh, for some peculiar reason AKID includes * SEQUENCE OF GeneralName. So look for a DirName. * There may be more than one but we only take any * notice of the first. */ GENERAL_NAMES *gens; GENERAL_NAME *gen; X509_NAME *nm = NULL; int i; gens = akid->issuer; for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { gen = sk_GENERAL_NAME_value(gens, i); if (gen->type == GEN_DIRNAME) { nm = gen->d.dirn; break; } } if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer))) return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; } return X509_V_OK; } LCRYPTO_ALIAS(X509_check_akid); uint32_t X509_get_extension_flags(X509 *x) { /* Call for side-effect of computing hash and caching extensions */ if (X509_check_purpose(x, -1, -1) != 1) return EXFLAG_INVALID; return x->ex_flags; } LCRYPTO_ALIAS(X509_get_extension_flags); uint32_t X509_get_key_usage(X509 *x) { /* Call for side-effect of computing hash and caching extensions */ if (X509_check_purpose(x, -1, -1) != 1) return 0; if (x->ex_flags & EXFLAG_KUSAGE) return x->ex_kusage; return UINT32_MAX; } LCRYPTO_ALIAS(X509_get_key_usage); uint32_t X509_get_extended_key_usage(X509 *x) { /* Call for side-effect of computing hash and caching extensions */ if (X509_check_purpose(x, -1, -1) != 1) return 0; if (x->ex_flags & EXFLAG_XKUSAGE) return x->ex_xkusage; return UINT32_MAX; } LCRYPTO_ALIAS(X509_get_extended_key_usage);