boringssl/crypto/x509v3/v3_ncons.c
David Benjamin 17cf2cb1d2 Work around language and compiler bug in memcpy, etc.
Most C standard library functions are undefined if passed NULL, even
when the corresponding length is zero. This gives them (and, in turn,
all functions which call them) surprising behavior on empty arrays.
Some compilers will miscompile code due to this rule. See also
https://www.imperialviolet.org/2016/06/26/nonnull.html

Add OPENSSL_memcpy, etc., wrappers which avoid this problem.

BUG=23

Change-Id: I95f42b23e92945af0e681264fffaf578e7f8465e
Reviewed-on: https://boringssl-review.googlesource.com/12928
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
2016-12-21 20:34:47 +00:00

486 lines
16 KiB
C

/* 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"
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++) {
BIO_printf(bp, "%X", p[0] << 8 | p[1]);
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_UNSUPPORTED_CONSTRAINT_TYPE: Unsupported constraint type.
* X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: bad 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);
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 nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
{
char *baseptr = (char *)base->data;
char *dnsptr = (char *)dns->data;
/* Empty matches everything */
if (!*baseptr)
return X509_V_OK;
/*
* Otherwise can add zero or more components on the left so compare RHS
* and if dns is longer and expect '.' as preceding character.
*/
if (dns->length > base->length) {
dnsptr += dns->length - base->length;
if (*baseptr != '.' && dnsptr[-1] != '.')
return X509_V_ERR_PERMITTED_VIOLATION;
}
if (OPENSSL_strcasecmp(baseptr, dnsptr))
return X509_V_ERR_PERMITTED_VIOLATION;
return X509_V_OK;
}
static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
{
const char *baseptr = (char *)base->data;
const char *emlptr = (char *)eml->data;
const char *baseat = strchr(baseptr, '@');
const char *emlat = strchr(emlptr, '@');
if (!emlat)
return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
/* Special case: inital '.' is RHS match */
if (!baseat && (*baseptr == '.')) {
if (eml->length > base->length) {
emlptr += eml->length - base->length;
if (!OPENSSL_strcasecmp(baseptr, emlptr))
return X509_V_OK;
}
return X509_V_ERR_PERMITTED_VIOLATION;
}
/* If we have anything before '@' match local part */
if (baseat) {
if (baseat != baseptr) {
if ((baseat - baseptr) != (emlat - emlptr))
return X509_V_ERR_PERMITTED_VIOLATION;
/* Case sensitive match of local part */
if (strncmp(baseptr, emlptr, emlat - emlptr))
return X509_V_ERR_PERMITTED_VIOLATION;
}
/* Position base after '@' */
baseptr = baseat + 1;
}
emlptr = emlat + 1;
/* Just have hostname left to match: case insensitive */
if (OPENSSL_strcasecmp(baseptr, emlptr))
return X509_V_ERR_PERMITTED_VIOLATION;
return X509_V_OK;
}
static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
{
const char *baseptr = (char *)base->data;
const char *hostptr = (char *)uri->data;
const char *p = strchr(hostptr, ':');
int hostlen;
/* Check for foo:// and skip past it */
if (!p || (p[1] != '/') || (p[2] != '/'))
return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
hostptr = p + 3;
/* Determine length of hostname part of URI */
/* Look for a port indicator as end of hostname first */
p = strchr(hostptr, ':');
/* Otherwise look for trailing slash */
if (!p)
p = strchr(hostptr, '/');
if (!p)
hostlen = strlen(hostptr);
else
hostlen = p - hostptr;
if (hostlen == 0)
return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
/* Special case: inital '.' is RHS match */
if (*baseptr == '.') {
if (hostlen > base->length) {
p = hostptr + hostlen - base->length;
if (!OPENSSL_strncasecmp(p, baseptr, base->length))
return X509_V_OK;
}
return X509_V_ERR_PERMITTED_VIOLATION;
}
if ((base->length != (int)hostlen)
|| OPENSSL_strncasecmp(hostptr, baseptr, hostlen))
return X509_V_ERR_PERMITTED_VIOLATION;
return X509_V_OK;
}