| /* v3_ncons.c */ |
| /* |
| * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL |
| * project. |
| */ |
| /* ==================================================================== |
| * Copyright (c) 2003 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 <stdio.h> |
| #include <string.h> |
| |
| #include <openssl/asn1t.h> |
| #include <openssl/conf.h> |
| #include <openssl/err.h> |
| #include <openssl/mem.h> |
| #include <openssl/obj.h> |
| #include <openssl/x509v3.h> |
| |
| #include "../internal.h" |
| #include "../x509/internal.h" |
| |
| |
| static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, |
| X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval); |
| static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a, |
| BIO *bp, int ind); |
| static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method, |
| STACK_OF(GENERAL_SUBTREE) *trees, BIO *bp, |
| int ind, const char *name); |
| static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip); |
| |
| static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc); |
| static int nc_match_single(GENERAL_NAME *sub, GENERAL_NAME *gen); |
| static int nc_dn(X509_NAME *sub, X509_NAME *nm); |
| static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns); |
| static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml); |
| static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base); |
| |
| const X509V3_EXT_METHOD v3_name_constraints = { |
| NID_name_constraints, |
| 0, |
| ASN1_ITEM_ref(NAME_CONSTRAINTS), |
| 0, |
| 0, |
| 0, |
| 0, |
| 0, |
| 0, |
| 0, |
| v2i_NAME_CONSTRAINTS, |
| i2r_NAME_CONSTRAINTS, |
| 0, |
| NULL, |
| }; |
| |
| ASN1_SEQUENCE(GENERAL_SUBTREE) = { |
| ASN1_SIMPLE(GENERAL_SUBTREE, base, GENERAL_NAME), |
| ASN1_IMP_OPT(GENERAL_SUBTREE, minimum, ASN1_INTEGER, 0), |
| ASN1_IMP_OPT(GENERAL_SUBTREE, maximum, ASN1_INTEGER, 1), |
| } ASN1_SEQUENCE_END(GENERAL_SUBTREE) |
| |
| ASN1_SEQUENCE(NAME_CONSTRAINTS) = { |
| ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, permittedSubtrees, |
| GENERAL_SUBTREE, 0), |
| ASN1_IMP_SEQUENCE_OF_OPT(NAME_CONSTRAINTS, excludedSubtrees, |
| GENERAL_SUBTREE, 1), |
| } ASN1_SEQUENCE_END(NAME_CONSTRAINTS) |
| |
| |
| IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE) |
| IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS) |
| |
| static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, |
| X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval) { |
| size_t i; |
| CONF_VALUE tval, *val; |
| STACK_OF(GENERAL_SUBTREE) **ptree = NULL; |
| NAME_CONSTRAINTS *ncons = NULL; |
| GENERAL_SUBTREE *sub = NULL; |
| ncons = NAME_CONSTRAINTS_new(); |
| if (!ncons) { |
| goto memerr; |
| } |
| for (i = 0; i < sk_CONF_VALUE_num(nval); i++) { |
| val = sk_CONF_VALUE_value(nval, i); |
| if (!strncmp(val->name, "permitted", 9) && val->name[9]) { |
| ptree = &ncons->permittedSubtrees; |
| tval.name = val->name + 10; |
| } else if (!strncmp(val->name, "excluded", 8) && val->name[8]) { |
| ptree = &ncons->excludedSubtrees; |
| tval.name = val->name + 9; |
| } else { |
| OPENSSL_PUT_ERROR(X509V3, X509V3_R_INVALID_SYNTAX); |
| goto err; |
| } |
| tval.value = val->value; |
| sub = GENERAL_SUBTREE_new(); |
| if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1)) { |
| goto err; |
| } |
| if (!*ptree) { |
| *ptree = sk_GENERAL_SUBTREE_new_null(); |
| } |
| if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub)) { |
| goto memerr; |
| } |
| sub = NULL; |
| } |
| |
| return ncons; |
| |
| memerr: |
| OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE); |
| err: |
| if (ncons) { |
| NAME_CONSTRAINTS_free(ncons); |
| } |
| if (sub) { |
| GENERAL_SUBTREE_free(sub); |
| } |
| |
| return NULL; |
| } |
| |
| static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a, |
| BIO *bp, int ind) { |
| NAME_CONSTRAINTS *ncons = a; |
| do_i2r_name_constraints(method, ncons->permittedSubtrees, bp, ind, |
| "Permitted"); |
| do_i2r_name_constraints(method, ncons->excludedSubtrees, bp, ind, "Excluded"); |
| return 1; |
| } |
| |
| static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method, |
| STACK_OF(GENERAL_SUBTREE) *trees, BIO *bp, |
| int ind, const char *name) { |
| GENERAL_SUBTREE *tree; |
| size_t i; |
| if (sk_GENERAL_SUBTREE_num(trees) > 0) { |
| BIO_printf(bp, "%*s%s:\n", ind, "", name); |
| } |
| for (i = 0; i < sk_GENERAL_SUBTREE_num(trees); i++) { |
| tree = sk_GENERAL_SUBTREE_value(trees, i); |
| BIO_printf(bp, "%*s", ind + 2, ""); |
| if (tree->base->type == GEN_IPADD) { |
| print_nc_ipadd(bp, tree->base->d.ip); |
| } else { |
| GENERAL_NAME_print(bp, tree->base); |
| } |
| BIO_puts(bp, "\n"); |
| } |
| return 1; |
| } |
| |
| static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip) { |
| int i, len; |
| unsigned char *p; |
| p = ip->data; |
| len = ip->length; |
| BIO_puts(bp, "IP:"); |
| if (len == 8) { |
| BIO_printf(bp, "%d.%d.%d.%d/%d.%d.%d.%d", p[0], p[1], p[2], p[3], p[4], |
| p[5], p[6], p[7]); |
| } else if (len == 32) { |
| for (i = 0; i < 16; i++) { |
| uint16_t v = ((uint16_t)p[0] << 8) | p[1]; |
| BIO_printf(bp, "%X", v); |
| p += 2; |
| if (i == 7) { |
| BIO_puts(bp, "/"); |
| } else if (i != 15) { |
| BIO_puts(bp, ":"); |
| } |
| } |
| } else { |
| BIO_printf(bp, "IP Address:<invalid>"); |
| } |
| return 1; |
| } |
| |
| //- |
| // Check a certificate conforms to a specified set of constraints. |
| // Return values: |
| // X509_V_OK: All constraints obeyed. |
| // X509_V_ERR_PERMITTED_VIOLATION: Permitted subtree violation. |
| // X509_V_ERR_EXCLUDED_VIOLATION: Excluded subtree violation. |
| // X509_V_ERR_SUBTREE_MINMAX: Min or max values present and matching type. |
| // X509_V_ERR_UNSPECIFIED: Unspecified error. |
| // X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type. |
| // X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: Bad or unsupported constraint |
| // syntax. |
| // X509_V_ERR_UNSUPPORTED_NAME_SYNTAX: Bad or unsupported syntax of name. |
| |
| int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc) { |
| int r, i; |
| size_t j; |
| X509_NAME *nm; |
| |
| nm = X509_get_subject_name(x); |
| |
| // Guard against certificates with an excessive number of names or |
| // constraints causing a computationally expensive name constraints |
| // check. |
| size_t name_count = |
| X509_NAME_entry_count(nm) + sk_GENERAL_NAME_num(x->altname); |
| size_t constraint_count = sk_GENERAL_SUBTREE_num(nc->permittedSubtrees) + |
| sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); |
| size_t check_count = constraint_count * name_count; |
| if (name_count < (size_t)X509_NAME_entry_count(nm) || |
| constraint_count < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees) || |
| (constraint_count && check_count / constraint_count != name_count) || |
| check_count > 1 << 20) { |
| return X509_V_ERR_UNSPECIFIED; |
| } |
| |
| if (X509_NAME_entry_count(nm) > 0) { |
| GENERAL_NAME gntmp; |
| gntmp.type = GEN_DIRNAME; |
| gntmp.d.directoryName = nm; |
| |
| r = nc_match(&gntmp, nc); |
| |
| if (r != X509_V_OK) { |
| return r; |
| } |
| |
| gntmp.type = GEN_EMAIL; |
| |
| // Process any email address attributes in subject name |
| |
| for (i = -1;;) { |
| X509_NAME_ENTRY *ne; |
| i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i); |
| if (i == -1) { |
| break; |
| } |
| ne = X509_NAME_get_entry(nm, i); |
| gntmp.d.rfc822Name = X509_NAME_ENTRY_get_data(ne); |
| if (gntmp.d.rfc822Name->type != V_ASN1_IA5STRING) { |
| return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; |
| } |
| |
| r = nc_match(&gntmp, nc); |
| |
| if (r != X509_V_OK) { |
| return r; |
| } |
| } |
| } |
| |
| for (j = 0; j < sk_GENERAL_NAME_num(x->altname); j++) { |
| GENERAL_NAME *gen = sk_GENERAL_NAME_value(x->altname, j); |
| r = nc_match(gen, nc); |
| if (r != X509_V_OK) { |
| return r; |
| } |
| } |
| |
| return X509_V_OK; |
| } |
| |
| static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc) { |
| GENERAL_SUBTREE *sub; |
| int r, match = 0; |
| size_t i; |
| |
| // Permitted subtrees: if any subtrees exist of matching the type at |
| // least one subtree must match. |
| |
| for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) { |
| sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i); |
| if (gen->type != sub->base->type) { |
| continue; |
| } |
| if (sub->minimum || sub->maximum) { |
| return X509_V_ERR_SUBTREE_MINMAX; |
| } |
| // If we already have a match don't bother trying any more |
| if (match == 2) { |
| continue; |
| } |
| if (match == 0) { |
| match = 1; |
| } |
| r = nc_match_single(gen, sub->base); |
| if (r == X509_V_OK) { |
| match = 2; |
| } else if (r != X509_V_ERR_PERMITTED_VIOLATION) { |
| return r; |
| } |
| } |
| |
| if (match == 1) { |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| |
| // Excluded subtrees: must not match any of these |
| |
| for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) { |
| sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i); |
| if (gen->type != sub->base->type) { |
| continue; |
| } |
| if (sub->minimum || sub->maximum) { |
| return X509_V_ERR_SUBTREE_MINMAX; |
| } |
| |
| r = nc_match_single(gen, sub->base); |
| if (r == X509_V_OK) { |
| return X509_V_ERR_EXCLUDED_VIOLATION; |
| } else if (r != X509_V_ERR_PERMITTED_VIOLATION) { |
| return r; |
| } |
| } |
| |
| return X509_V_OK; |
| } |
| |
| static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base) { |
| switch (base->type) { |
| case GEN_DIRNAME: |
| return nc_dn(gen->d.directoryName, base->d.directoryName); |
| |
| case GEN_DNS: |
| return nc_dns(gen->d.dNSName, base->d.dNSName); |
| |
| case GEN_EMAIL: |
| return nc_email(gen->d.rfc822Name, base->d.rfc822Name); |
| |
| case GEN_URI: |
| return nc_uri(gen->d.uniformResourceIdentifier, |
| base->d.uniformResourceIdentifier); |
| |
| default: |
| return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE; |
| } |
| } |
| |
| // directoryName name constraint matching. The canonical encoding of |
| // X509_NAME makes this comparison easy. It is matched if the subtree is a |
| // subset of the name. |
| |
| static int nc_dn(X509_NAME *nm, X509_NAME *base) { |
| // Ensure canonical encodings are up to date. |
| if (nm->modified && i2d_X509_NAME(nm, NULL) < 0) { |
| return X509_V_ERR_OUT_OF_MEM; |
| } |
| if (base->modified && i2d_X509_NAME(base, NULL) < 0) { |
| return X509_V_ERR_OUT_OF_MEM; |
| } |
| if (base->canon_enclen > nm->canon_enclen) { |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| if (OPENSSL_memcmp(base->canon_enc, nm->canon_enc, base->canon_enclen)) { |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| return X509_V_OK; |
| } |
| |
| static int starts_with(const CBS *cbs, uint8_t c) { |
| return CBS_len(cbs) > 0 && CBS_data(cbs)[0] == c; |
| } |
| |
| static int equal_case(const CBS *a, const CBS *b) { |
| if (CBS_len(a) != CBS_len(b)) { |
| return 0; |
| } |
| // Note we cannot use |OPENSSL_strncasecmp| because that would stop |
| // iterating at NUL. |
| const uint8_t *a_data = CBS_data(a), *b_data = CBS_data(b); |
| for (size_t i = 0; i < CBS_len(a); i++) { |
| if (OPENSSL_tolower(a_data[i]) != OPENSSL_tolower(b_data[i])) { |
| return 0; |
| } |
| } |
| return 1; |
| } |
| |
| static int has_suffix_case(const CBS *a, const CBS *b) { |
| if (CBS_len(a) < CBS_len(b)) { |
| return 0; |
| } |
| CBS copy = *a; |
| CBS_skip(©, CBS_len(a) - CBS_len(b)); |
| return equal_case(©, b); |
| } |
| |
| static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base) { |
| CBS dns_cbs, base_cbs; |
| CBS_init(&dns_cbs, dns->data, dns->length); |
| CBS_init(&base_cbs, base->data, base->length); |
| |
| // Empty matches everything |
| if (CBS_len(&base_cbs) == 0) { |
| return X509_V_OK; |
| } |
| |
| // If |base_cbs| begins with a '.', do a simple suffix comparison. This is |
| // not part of RFC5280, but is part of OpenSSL's original behavior. |
| if (starts_with(&base_cbs, '.')) { |
| if (has_suffix_case(&dns_cbs, &base_cbs)) { |
| return X509_V_OK; |
| } |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| |
| // Otherwise can add zero or more components on the left so compare RHS |
| // and if dns is longer and expect '.' as preceding character. |
| if (CBS_len(&dns_cbs) > CBS_len(&base_cbs)) { |
| uint8_t dot; |
| if (!CBS_skip(&dns_cbs, CBS_len(&dns_cbs) - CBS_len(&base_cbs) - 1) || |
| !CBS_get_u8(&dns_cbs, &dot) || dot != '.') { |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| } |
| |
| if (!equal_case(&dns_cbs, &base_cbs)) { |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| |
| return X509_V_OK; |
| } |
| |
| static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base) { |
| CBS eml_cbs, base_cbs; |
| CBS_init(&eml_cbs, eml->data, eml->length); |
| CBS_init(&base_cbs, base->data, base->length); |
| |
| // TODO(davidben): In OpenSSL 1.1.1, this switched from the first '@' to the |
| // last one. Match them here, or perhaps do an actual parse. Looks like |
| // multiple '@'s may be allowed in quoted strings. |
| CBS eml_local, base_local; |
| if (!CBS_get_until_first(&eml_cbs, &eml_local, '@')) { |
| return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; |
| } |
| int base_has_at = CBS_get_until_first(&base_cbs, &base_local, '@'); |
| |
| // Special case: inital '.' is RHS match |
| if (!base_has_at && starts_with(&base_cbs, '.')) { |
| if (has_suffix_case(&eml_cbs, &base_cbs)) { |
| return X509_V_OK; |
| } |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| |
| // If we have anything before '@' match local part |
| if (base_has_at) { |
| // TODO(davidben): This interprets a constraint of "@example.com" as |
| // "example.com", which is not part of RFC5280. |
| if (CBS_len(&base_local) > 0) { |
| // Case sensitive match of local part |
| if (!CBS_mem_equal(&base_local, CBS_data(&eml_local), |
| CBS_len(&eml_local))) { |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| } |
| // Position base after '@' |
| assert(starts_with(&base_cbs, '@')); |
| CBS_skip(&base_cbs, 1); |
| } |
| |
| // Just have hostname left to match: case insensitive |
| assert(starts_with(&eml_cbs, '@')); |
| CBS_skip(&eml_cbs, 1); |
| if (!equal_case(&base_cbs, &eml_cbs)) { |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| |
| return X509_V_OK; |
| } |
| |
| static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base) { |
| CBS uri_cbs, base_cbs; |
| CBS_init(&uri_cbs, uri->data, uri->length); |
| CBS_init(&base_cbs, base->data, base->length); |
| |
| // Check for foo:// and skip past it |
| CBS scheme; |
| uint8_t byte; |
| if (!CBS_get_until_first(&uri_cbs, &scheme, ':') || |
| !CBS_skip(&uri_cbs, 1) || // Skip the colon |
| !CBS_get_u8(&uri_cbs, &byte) || byte != '/' || |
| !CBS_get_u8(&uri_cbs, &byte) || byte != '/') { |
| return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; |
| } |
| |
| // Look for a port indicator as end of hostname first. Otherwise look for |
| // trailing slash, or the end of the string. |
| // TODO(davidben): This is not a correct URI parser and mishandles IPv6 |
| // literals. |
| CBS host; |
| if (!CBS_get_until_first(&uri_cbs, &host, ':') && |
| !CBS_get_until_first(&uri_cbs, &host, '/')) { |
| host = uri_cbs; |
| } |
| |
| if (CBS_len(&host) == 0) { |
| return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; |
| } |
| |
| // Special case: inital '.' is RHS match |
| if (starts_with(&base_cbs, '.')) { |
| if (has_suffix_case(&host, &base_cbs)) { |
| return X509_V_OK; |
| } |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| |
| if (!equal_case(&base_cbs, &host)) { |
| return X509_V_ERR_PERMITTED_VIOLATION; |
| } |
| |
| return X509_V_OK; |
| } |