-/* 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).
+ * Copyright 2003-2018 The OpenSSL Project Authors. All Rights Reserved.
*
+ * Licensed under the OpenSSL license (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 <stdio.h>
#include "internal/cryptlib.h"
+#include "internal/numbers.h"
+#include <stdio.h>
+#include "internal/asn1_int.h"
#include <openssl/asn1t.h>
#include <openssl/conf.h>
#include <openssl/x509v3.h>
+#include <openssl/bn.h>
#include "internal/x509_int.h"
#include "ext_dat.h"
BIO *bp, int ind);
static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
STACK_OF(GENERAL_SUBTREE) *trees, BIO *bp,
- int ind, char *name);
+ 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);
IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)
IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)
+/*
+ * We cannot use strncasecmp here because that applies locale specific rules.
+ * For example in Turkish 'I' is not the uppercase character for 'i'. We need to
+ * do a simple ASCII case comparison ignoring the locale (that is why we use
+ * numeric constants below).
+ */
+static int ia5ncasecmp(const char *s1, const char *s2, size_t n)
+{
+ for (; n > 0; n--, s1++, s2++) {
+ if (*s1 != *s2) {
+ unsigned char c1 = (unsigned char)*s1, c2 = (unsigned char)*s2;
+
+ /* Convert to lower case */
+ if (c1 >= 0x41 /* A */ && c1 <= 0x5A /* Z */)
+ c1 += 0x20;
+ if (c2 >= 0x41 /* A */ && c2 <= 0x5A /* Z */)
+ c2 += 0x20;
+
+ if (c1 == c2)
+ continue;
+
+ if (c1 < c2)
+ return -1;
+
+ /* c1 > c2 */
+ return 1;
+ } else if (*s1 == 0) {
+ /* If we get here we know that *s2 == 0 too */
+ return 0;
+ }
+ }
+
+ return 0;
+}
+
+static int ia5casecmp(const char *s1, const char *s2)
+{
+ return ia5ncasecmp(s1, s2, SIZE_MAX);
+}
+
static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval)
{
static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,
STACK_OF(GENERAL_SUBTREE) *trees,
- BIO *bp, int ind, char *name)
+ BIO *bp, int ind, const char *name)
{
GENERAL_SUBTREE *tree;
int i;
return 1;
}
+#define NAME_CHECK_MAX (1 << 20)
+
+static int add_lengths(int *out, int a, int b)
+{
+ /* sk_FOO_num(NULL) returns -1 but is effectively 0 when iterating. */
+ if (a < 0)
+ a = 0;
+ if (b < 0)
+ b = 0;
+
+ if (a > INT_MAX - b)
+ return 0;
+ *out = a + b;
+ return 1;
+}
+
/*-
* Check a certificate conforms to a specified set of constraints.
* Return values:
int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc)
{
- int r, i;
+ int r, i, name_count, constraint_count;
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.
+ */
+ if (!add_lengths(&name_count, X509_NAME_entry_count(nm),
+ sk_GENERAL_NAME_num(x->altname))
+ || !add_lengths(&constraint_count,
+ sk_GENERAL_SUBTREE_num(nc->permittedSubtrees),
+ sk_GENERAL_SUBTREE_num(nc->excludedSubtrees))
+ || (name_count > 0 && constraint_count > NAME_CHECK_MAX / name_count))
+ return X509_V_ERR_UNSPECIFIED;
+
if (X509_NAME_entry_count(nm) > 0) {
GENERAL_NAME gntmp;
gntmp.type = GEN_DIRNAME;
/* Process any email address attributes in subject name */
for (i = -1;;) {
- X509_NAME_ENTRY *ne;
+ const X509_NAME_ENTRY *ne;
+
i = X509_NAME_get_index_by_NID(nm, NID_pkcs9_emailAddress, i);
if (i == -1)
break;
}
+static int cn2dnsid(ASN1_STRING *cn, unsigned char **dnsid, size_t *idlen)
+{
+ int utf8_length;
+ unsigned char *utf8_value;
+ int i;
+ int isdnsname = 0;
+
+ /* Don't leave outputs uninitialized */
+ *dnsid = NULL;
+ *idlen = 0;
+
+ /*-
+ * Per RFC 6125, DNS-IDs representing internationalized domain names appear
+ * in certificates in A-label encoded form:
+ *
+ * https://tools.ietf.org/html/rfc6125#section-6.4.2
+ *
+ * The same applies to CNs which are intended to represent DNS names.
+ * However, while in the SAN DNS-IDs are IA5Strings, as CNs they may be
+ * needlessly encoded in 16-bit Unicode. We perform a conversion to UTF-8
+ * to ensure that we get an ASCII representation of any CNs that are
+ * representable as ASCII, but just not encoded as ASCII. The UTF-8 form
+ * may contain some non-ASCII octets, and that's fine, such CNs are not
+ * valid legacy DNS names.
+ *
+ * Note, 'int' is the return type of ASN1_STRING_to_UTF8() so that's what
+ * we must use for 'utf8_length'.
+ */
+ if ((utf8_length = ASN1_STRING_to_UTF8(&utf8_value, cn)) < 0)
+ return X509_V_ERR_OUT_OF_MEM;
+
+ /*
+ * Some certificates have had names that include a *trailing* NUL byte.
+ * Remove these harmless NUL characters. They would otherwise yield false
+ * alarms with the following embedded NUL check.
+ */
+ while (utf8_length > 0 && utf8_value[utf8_length - 1] == '\0')
+ --utf8_length;
+
+ /* Reject *embedded* NULs */
+ if ((size_t)utf8_length != strlen((char *)utf8_value)) {
+ OPENSSL_free(utf8_value);
+ return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
+ }
+
+ /*
+ * XXX: Deviation from strict DNS name syntax, also check names with '_'
+ * Check DNS name syntax, any '-' or '.' must be internal,
+ * and on either side of each '.' we can't have a '-' or '.'.
+ *
+ * If the name has just one label, we don't consider it a DNS name. This
+ * means that "CN=sometld" cannot be precluded by DNS name constraints, but
+ * that is not a problem.
+ */
+ for (i = 0; i < utf8_length; ++i) {
+ unsigned char c = utf8_value[i];
+
+ if ((c >= 'a' && c <= 'z')
+ || (c >= 'A' && c <= 'Z')
+ || (c >= '0' && c <= '9')
+ || c == '_')
+ continue;
+
+ /* Dot and hyphen cannot be first or last. */
+ if (i > 0 && i < utf8_length - 1) {
+ if (c == '-')
+ continue;
+ /*
+ * Next to a dot the preceding and following characters must not be
+ * another dot or a hyphen. Otherwise, record that the name is
+ * plausible, since it has two or more labels.
+ */
+ if (c == '.'
+ && utf8_value[i + 1] != '.'
+ && utf8_value[i - 1] != '-'
+ && utf8_value[i + 1] != '-') {
+ isdnsname = 1;
+ continue;
+ }
+ }
+ isdnsname = 0;
+ break;
+ }
+
+ if (isdnsname) {
+ *dnsid = utf8_value;
+ *idlen = (size_t)utf8_length;
+ return X509_V_OK;
+ }
+ OPENSSL_free(utf8_value);
+ return X509_V_OK;
+}
+
+/*
+ * Check CN against DNS-ID name constraints.
+ */
+int NAME_CONSTRAINTS_check_CN(X509 *x, NAME_CONSTRAINTS *nc)
+{
+ int r, i;
+ X509_NAME *nm = X509_get_subject_name(x);
+ ASN1_STRING stmp;
+ GENERAL_NAME gntmp;
+
+ stmp.flags = 0;
+ stmp.type = V_ASN1_IA5STRING;
+ gntmp.type = GEN_DNS;
+ gntmp.d.dNSName = &stmp;
+
+ /* Process any commonName attributes in subject name */
+
+ for (i = -1;;) {
+ X509_NAME_ENTRY *ne;
+ ASN1_STRING *cn;
+ unsigned char *idval;
+ size_t idlen;
+
+ i = X509_NAME_get_index_by_NID(nm, NID_commonName, i);
+ if (i == -1)
+ break;
+ ne = X509_NAME_get_entry(nm, i);
+ cn = X509_NAME_ENTRY_get_data(ne);
+
+ /* Only process attributes that look like host names */
+ if ((r = cn2dnsid(cn, &idval, &idlen)) != X509_V_OK)
+ return r;
+ if (idlen == 0)
+ continue;
+
+ stmp.length = idlen;
+ stmp.data = idval;
+ r = nc_match(&gntmp, nc);
+ OPENSSL_free(idval);
+ if (r != X509_V_OK)
+ return r;
+ }
+ return X509_V_OK;
+}
+
+/*
+ * Return nonzero if the GeneralSubtree has valid 'minimum' field
+ * (must be absent or 0) and valid 'maximum' field (must be absent).
+ */
+static int nc_minmax_valid(GENERAL_SUBTREE *sub) {
+ BIGNUM *bn = NULL;
+ int ok = 1;
+
+ if (sub->maximum)
+ ok = 0;
+
+ if (sub->minimum) {
+ bn = ASN1_INTEGER_to_BN(sub->minimum, NULL);
+ if (bn == NULL || !BN_is_zero(bn))
+ ok = 0;
+ BN_free(bn);
+ }
+
+ return ok;
+}
+
static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)
{
GENERAL_SUBTREE *sub;
sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);
if (gen->type != sub->base->type)
continue;
- if (sub->minimum || sub->maximum)
+ if (!nc_minmax_valid(sub))
return X509_V_ERR_SUBTREE_MINMAX;
/* If we already have a match don't bother trying any more */
if (match == 2)
sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);
if (gen->type != sub->base->type)
continue;
- if (sub->minimum || sub->maximum)
+ if (!nc_minmax_valid(sub))
return X509_V_ERR_SUBTREE_MINMAX;
r = nc_match_single(gen, sub->base);
return X509_V_ERR_PERMITTED_VIOLATION;
}
- if (strcasecmp(baseptr, dnsptr))
+ if (ia5casecmp(baseptr, dnsptr))
return X509_V_ERR_PERMITTED_VIOLATION;
return X509_V_OK;
const char *emlat = strchr(emlptr, '@');
if (!emlat)
return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
- /* Special case: inital '.' is RHS match */
+ /* Special case: initial '.' is RHS match */
if (!baseat && (*baseptr == '.')) {
if (eml->length > base->length) {
emlptr += eml->length - base->length;
- if (strcasecmp(baseptr, emlptr) == 0)
+ if (ia5casecmp(baseptr, emlptr) == 0)
return X509_V_OK;
}
return X509_V_ERR_PERMITTED_VIOLATION;
}
emlptr = emlat + 1;
/* Just have hostname left to match: case insensitive */
- if (strcasecmp(baseptr, emlptr))
+ if (ia5casecmp(baseptr, emlptr))
return X509_V_ERR_PERMITTED_VIOLATION;
return X509_V_OK;
if (hostlen == 0)
return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
- /* Special case: inital '.' is RHS match */
+ /* Special case: initial '.' is RHS match */
if (*baseptr == '.') {
if (hostlen > base->length) {
p = hostptr + hostlen - base->length;
- if (strncasecmp(p, baseptr, base->length) == 0)
+ if (ia5ncasecmp(p, baseptr, base->length) == 0)
return X509_V_OK;
}
return X509_V_ERR_PERMITTED_VIOLATION;
}
if ((base->length != (int)hostlen)
- || strncasecmp(hostptr, baseptr, hostlen))
+ || ia5ncasecmp(hostptr, baseptr, hostlen))
return X509_V_ERR_PERMITTED_VIOLATION;
return X509_V_OK;
projects / openssl.git / blobdiff