diff options
Diffstat (limited to 'crypto/x509v3/v3_ncons.c')
-rw-r--r-- | crypto/x509v3/v3_ncons.c | 301 |
1 files changed, 228 insertions, 73 deletions
diff --git a/crypto/x509v3/v3_ncons.c b/crypto/x509v3/v3_ncons.c index 1184091ccf30..9a2cd5af00c7 100644 --- a/crypto/x509v3/v3_ncons.c +++ b/crypto/x509v3/v3_ncons.c @@ -1,68 +1,23 @@ -/* 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 "internal/cryptlib.h" +#include "internal/numbers.h" #include <stdio.h> -#include "cryptlib.h" +#include "internal/asn1_int.h" #include <openssl/asn1t.h> #include <openssl/conf.h> #include <openssl/x509v3.h> +#include "internal/x509_int.h" +#include "ext_dat.h" + static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval); @@ -70,7 +25,7 @@ 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, 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); @@ -79,6 +34,7 @@ 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); +static int nc_ip(ASN1_OCTET_STRING *ip, ASN1_OCTET_STRING *base); const X509V3_EXT_METHOD v3_name_constraints = { NID_name_constraints, 0, @@ -144,8 +100,7 @@ static int ia5ncasecmp(const char *s1, const char *s2, size_t n) static int ia5casecmp(const char *s1, const char *s2) { - /* No portable definition of SIZE_MAX, so we use (size_t)(-1) instead */ - return ia5ncasecmp(s1, s2, (size_t)(-1)); + return ia5ncasecmp(s1, s2, SIZE_MAX); } static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, @@ -156,15 +111,16 @@ static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, STACK_OF(GENERAL_SUBTREE) **ptree = NULL; NAME_CONSTRAINTS *ncons = NULL; GENERAL_SUBTREE *sub = NULL; + ncons = NAME_CONSTRAINTS_new(); - if (!ncons) + if (ncons == NULL) 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]) { + if (strncmp(val->name, "permitted", 9) == 0 && val->name[9]) { ptree = &ncons->permittedSubtrees; tval.name = val->name + 10; - } else if (!strncmp(val->name, "excluded", 8) && val->name[8]) { + } else if (strncmp(val->name, "excluded", 8) == 0 && val->name[8]) { ptree = &ncons->excludedSubtrees; tval.name = val->name + 9; } else { @@ -177,9 +133,9 @@ static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, goto memerr; if (!v2i_GENERAL_NAME_ex(sub->base, method, ctx, &tval, 1)) goto err; - if (!*ptree) + if (*ptree == NULL) *ptree = sk_GENERAL_SUBTREE_new_null(); - if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub)) + if (*ptree == NULL || !sk_GENERAL_SUBTREE_push(*ptree, sub)) goto memerr; sub = NULL; } @@ -189,10 +145,8 @@ static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, memerr: X509V3err(X509V3_F_V2I_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE); err: - if (ncons) - NAME_CONSTRAINTS_free(ncons); - if (sub) - GENERAL_SUBTREE_free(sub); + NAME_CONSTRAINTS_free(ncons); + GENERAL_SUBTREE_free(sub); return NULL; } @@ -210,7 +164,7 @@ static int i2r_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method, void *a, 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; @@ -252,6 +206,22 @@ static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip) 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: @@ -266,11 +236,23 @@ static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip) 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; @@ -286,7 +268,8 @@ int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc) /* 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; @@ -314,6 +297,144 @@ int NAME_CONSTRAINTS_check(X509 *x, NAME_CONSTRAINTS *nc) } +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; +} + static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc) { GENERAL_SUBTREE *sub; @@ -382,6 +503,9 @@ static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base) return nc_uri(gen->d.uniformResourceIdentifier, base->d.uniformResourceIdentifier); + case GEN_IPADD: + return nc_ip(gen->d.iPAddress, base->d.iPAddress); + default: return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE; } @@ -441,7 +565,7 @@ static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base) 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; @@ -501,7 +625,7 @@ static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base) 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; @@ -518,3 +642,34 @@ static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base) return X509_V_OK; } + +static int nc_ip(ASN1_OCTET_STRING *ip, ASN1_OCTET_STRING *base) +{ + int hostlen, baselen, i; + unsigned char *hostptr, *baseptr, *maskptr; + hostptr = ip->data; + hostlen = ip->length; + baseptr = base->data; + baselen = base->length; + + /* Invalid if not IPv4 or IPv6 */ + if (!((hostlen == 4) || (hostlen == 16))) + return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; + if (!((baselen == 8) || (baselen == 32))) + return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX; + + /* Do not match IPv4 with IPv6 */ + if (hostlen * 2 != baselen) + return X509_V_ERR_PERMITTED_VIOLATION; + + maskptr = base->data + hostlen; + + /* Considering possible not aligned base ipAddress */ + /* Not checking for wrong mask definition: i.e.: 255.0.255.0 */ + for (i = 0; i < hostlen; i++) + if ((hostptr[i] & maskptr[i]) != (baseptr[i] & maskptr[i])) + return X509_V_ERR_PERMITTED_VIOLATION; + + return X509_V_OK; + +} |