ref: 009439541d2c6e8af2596f8fb1b4df85861fd212
dir: /third_party/boringssl/src/crypto/x509/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/x509.h>
#include "../internal.h"
#include "internal.h"
static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
const X509V3_CTX *ctx,
const 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, const 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(const ASN1_IA5STRING *sub, const ASN1_IA5STRING *dns);
static int nc_email(const ASN1_IA5STRING *sub, const ASN1_IA5STRING *eml);
static int nc_uri(const ASN1_IA5STRING *uri, const 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,
const X509V3_CTX *ctx,
const STACK_OF(CONF_VALUE) *nval) {
STACK_OF(GENERAL_SUBTREE) **ptree = NULL;
NAME_CONSTRAINTS *ncons = NULL;
GENERAL_SUBTREE *sub = NULL;
ncons = NAME_CONSTRAINTS_new();
if (!ncons) {
goto err;
}
for (size_t i = 0; i < sk_CONF_VALUE_num(nval); i++) {
const CONF_VALUE *val = sk_CONF_VALUE_value(nval, i);
CONF_VALUE tval;
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 err;
}
sub = NULL;
}
return ncons;
err:
NAME_CONSTRAINTS_free(ncons);
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, const 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;;) {
i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i);
if (i == -1) {
break;
}
const X509_NAME_ENTRY *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(const ASN1_IA5STRING *dns, const 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(const ASN1_IA5STRING *eml, const 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: initial '.' 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(const ASN1_IA5STRING *uri, const 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: initial '.' 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;
}