boringssl/crypto/x509/x_name.c
David Benjamin e31e0123ea Add size limit to X509_NAME structure.
This adds an explicit limit to the size of an X509_NAME structure. Some
part of OpenSSL (e.g. TLS) already effectively limit the size due to
restrictions on certificate size.

See also upstream's 65cb92f4da37a3895437f0c9940ee0bcf9f28c8a, although this is
different from upstream's. Upstream's version bounds both the X509_NAME *and*
any data after it in the immediately containing structure. While adding a bound
on all of crypto/asn1 is almost certainly a good idea (will look into that for
a follow-up), it seems bizarre and unnecessary to have X509_NAME affect its
parent.

Change-Id: Ica2136bcd1455d7c501ccc6ef2a19bc5ed042501
Reviewed-on: https://boringssl-review.googlesource.com/7846
Reviewed-by: Adam Langley <agl@google.com>
2016-05-03 16:43:52 +00:00

549 lines
17 KiB
C

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* 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 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 acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS 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 AUTHOR OR 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.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#include <ctype.h>
#include <string.h>
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/buf.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/stack.h>
#include <openssl/x509.h>
#include "../asn1/asn1_locl.h"
typedef STACK_OF(X509_NAME_ENTRY) STACK_OF_X509_NAME_ENTRY;
DECLARE_STACK_OF(STACK_OF_X509_NAME_ENTRY)
/*
* Maximum length of X509_NAME: much larger than anything we should
* ever see in practice.
*/
#define X509_NAME_MAX (1024 * 1024)
static int x509_name_ex_d2i(ASN1_VALUE **val,
const unsigned char **in, long len,
const ASN1_ITEM *it,
int tag, int aclass, char opt, ASN1_TLC *ctx);
static int x509_name_ex_i2d(ASN1_VALUE **val, unsigned char **out,
const ASN1_ITEM *it, int tag, int aclass);
static int x509_name_ex_new(ASN1_VALUE **val, const ASN1_ITEM *it);
static void x509_name_ex_free(ASN1_VALUE **val, const ASN1_ITEM *it);
static int x509_name_encode(X509_NAME *a);
static int x509_name_canon(X509_NAME *a);
static int asn1_string_canon(ASN1_STRING *out, ASN1_STRING *in);
static int i2d_name_canon(STACK_OF(STACK_OF_X509_NAME_ENTRY) * intname,
unsigned char **in);
static int x509_name_ex_print(BIO *out, ASN1_VALUE **pval,
int indent,
const char *fname, const ASN1_PCTX *pctx);
ASN1_SEQUENCE(X509_NAME_ENTRY) = {
ASN1_SIMPLE(X509_NAME_ENTRY, object, ASN1_OBJECT),
ASN1_SIMPLE(X509_NAME_ENTRY, value, ASN1_PRINTABLE)
} ASN1_SEQUENCE_END(X509_NAME_ENTRY)
IMPLEMENT_ASN1_FUNCTIONS(X509_NAME_ENTRY)
IMPLEMENT_ASN1_DUP_FUNCTION(X509_NAME_ENTRY)
/*
* For the "Name" type we need a SEQUENCE OF { SET OF X509_NAME_ENTRY } so
* declare two template wrappers for this
*/
ASN1_ITEM_TEMPLATE(X509_NAME_ENTRIES) =
ASN1_EX_TEMPLATE_TYPE(ASN1_TFLG_SET_OF, 0, RDNS, X509_NAME_ENTRY)
ASN1_ITEM_TEMPLATE_END(X509_NAME_ENTRIES)
ASN1_ITEM_TEMPLATE(X509_NAME_INTERNAL) =
ASN1_EX_TEMPLATE_TYPE(ASN1_TFLG_SEQUENCE_OF, 0, Name, X509_NAME_ENTRIES)
ASN1_ITEM_TEMPLATE_END(X509_NAME_INTERNAL)
/*
* Normally that's where it would end: we'd have two nested STACK structures
* representing the ASN1. Unfortunately X509_NAME uses a completely different
* form and caches encodings so we have to process the internal form and
* convert to the external form.
*/
static const ASN1_EXTERN_FUNCS x509_name_ff = {
NULL,
x509_name_ex_new,
x509_name_ex_free,
0, /* Default clear behaviour is OK */
x509_name_ex_d2i,
x509_name_ex_i2d,
x509_name_ex_print
};
IMPLEMENT_EXTERN_ASN1(X509_NAME, V_ASN1_SEQUENCE, x509_name_ff)
IMPLEMENT_ASN1_FUNCTIONS(X509_NAME)
IMPLEMENT_ASN1_DUP_FUNCTION(X509_NAME)
static int x509_name_ex_new(ASN1_VALUE **val, const ASN1_ITEM *it)
{
X509_NAME *ret = NULL;
ret = OPENSSL_malloc(sizeof(X509_NAME));
if (!ret)
goto memerr;
if ((ret->entries = sk_X509_NAME_ENTRY_new_null()) == NULL)
goto memerr;
if ((ret->bytes = BUF_MEM_new()) == NULL)
goto memerr;
ret->canon_enc = NULL;
ret->canon_enclen = 0;
ret->modified = 1;
*val = (ASN1_VALUE *)ret;
return 1;
memerr:
OPENSSL_PUT_ERROR(X509, ERR_R_MALLOC_FAILURE);
if (ret) {
if (ret->entries)
sk_X509_NAME_ENTRY_free(ret->entries);
OPENSSL_free(ret);
}
return 0;
}
static void x509_name_ex_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
{
X509_NAME *a;
if (!pval || !*pval)
return;
a = (X509_NAME *)*pval;
BUF_MEM_free(a->bytes);
sk_X509_NAME_ENTRY_pop_free(a->entries, X509_NAME_ENTRY_free);
if (a->canon_enc)
OPENSSL_free(a->canon_enc);
OPENSSL_free(a);
*pval = NULL;
}
static void local_sk_X509_NAME_ENTRY_free(STACK_OF(X509_NAME_ENTRY) *ne)
{
sk_X509_NAME_ENTRY_free(ne);
}
static void local_sk_X509_NAME_ENTRY_pop_free(STACK_OF(X509_NAME_ENTRY) *ne)
{
sk_X509_NAME_ENTRY_pop_free(ne, X509_NAME_ENTRY_free);
}
static int x509_name_ex_d2i(ASN1_VALUE **val,
const unsigned char **in, long len,
const ASN1_ITEM *it, int tag, int aclass,
char opt, ASN1_TLC *ctx)
{
const unsigned char *p = *in, *q;
union {
STACK_OF(STACK_OF_X509_NAME_ENTRY) *s;
ASN1_VALUE *a;
} intname = {
NULL
};
union {
X509_NAME *x;
ASN1_VALUE *a;
} nm = {
NULL
};
size_t i, j;
int ret;
STACK_OF(X509_NAME_ENTRY) *entries;
X509_NAME_ENTRY *entry;
/* Bound the size of an X509_NAME we are willing to parse. */
if (len > X509_NAME_MAX) {
len = X509_NAME_MAX;
}
q = p;
/* Get internal representation of Name */
ret = ASN1_item_ex_d2i(&intname.a,
&p, len, ASN1_ITEM_rptr(X509_NAME_INTERNAL),
tag, aclass, opt, ctx);
if (ret <= 0)
return ret;
if (*val)
x509_name_ex_free(val, NULL);
/* We've decoded it: now cache encoding */
if (!x509_name_ex_new(&nm.a, NULL) || !BUF_MEM_grow(nm.x->bytes, p - q)) {
sk_STACK_OF_X509_NAME_ENTRY_pop_free(intname.s,
local_sk_X509_NAME_ENTRY_pop_free);
goto err;
}
memcpy(nm.x->bytes->data, q, p - q);
/* Convert internal representation to X509_NAME structure */
for (i = 0; i < sk_STACK_OF_X509_NAME_ENTRY_num(intname.s); i++) {
entries = sk_STACK_OF_X509_NAME_ENTRY_value(intname.s, i);
for (j = 0; j < sk_X509_NAME_ENTRY_num(entries); j++) {
entry = sk_X509_NAME_ENTRY_value(entries, j);
entry->set = i;
if (!sk_X509_NAME_ENTRY_push(nm.x->entries, entry))
goto err;
}
sk_X509_NAME_ENTRY_free(entries);
}
sk_STACK_OF_X509_NAME_ENTRY_free(intname.s);
ret = x509_name_canon(nm.x);
if (!ret)
goto err;
nm.x->modified = 0;
*val = nm.a;
*in = p;
return ret;
err:
if (nm.x != NULL)
X509_NAME_free(nm.x);
OPENSSL_PUT_ERROR(X509, ERR_R_ASN1_LIB);
return 0;
}
static int x509_name_ex_i2d(ASN1_VALUE **val, unsigned char **out,
const ASN1_ITEM *it, int tag, int aclass)
{
int ret;
X509_NAME *a = (X509_NAME *)*val;
if (a->modified) {
ret = x509_name_encode(a);
if (ret < 0)
return ret;
ret = x509_name_canon(a);
if (ret < 0)
return ret;
}
ret = a->bytes->length;
if (out != NULL) {
memcpy(*out, a->bytes->data, ret);
*out += ret;
}
return ret;
}
static int x509_name_encode(X509_NAME *a)
{
union {
STACK_OF(STACK_OF_X509_NAME_ENTRY) *s;
ASN1_VALUE *a;
} intname = {
NULL
};
int len;
unsigned char *p;
STACK_OF(X509_NAME_ENTRY) *entries = NULL;
X509_NAME_ENTRY *entry;
int set = -1;
size_t i;
intname.s = sk_STACK_OF_X509_NAME_ENTRY_new_null();
if (!intname.s)
goto memerr;
for (i = 0; i < sk_X509_NAME_ENTRY_num(a->entries); i++) {
entry = sk_X509_NAME_ENTRY_value(a->entries, i);
if (entry->set != set) {
entries = sk_X509_NAME_ENTRY_new_null();
if (!entries)
goto memerr;
if (!sk_STACK_OF_X509_NAME_ENTRY_push(intname.s, entries))
goto memerr;
set = entry->set;
}
if (!sk_X509_NAME_ENTRY_push(entries, entry))
goto memerr;
}
len = ASN1_item_ex_i2d(&intname.a, NULL,
ASN1_ITEM_rptr(X509_NAME_INTERNAL), -1, -1);
if (!BUF_MEM_grow(a->bytes, len))
goto memerr;
p = (unsigned char *)a->bytes->data;
ASN1_item_ex_i2d(&intname.a,
&p, ASN1_ITEM_rptr(X509_NAME_INTERNAL), -1, -1);
sk_STACK_OF_X509_NAME_ENTRY_pop_free(intname.s,
local_sk_X509_NAME_ENTRY_free);
a->modified = 0;
return len;
memerr:
sk_STACK_OF_X509_NAME_ENTRY_pop_free(intname.s,
local_sk_X509_NAME_ENTRY_free);
OPENSSL_PUT_ERROR(X509, ERR_R_MALLOC_FAILURE);
return -1;
}
static int x509_name_ex_print(BIO *out, ASN1_VALUE **pval,
int indent,
const char *fname, const ASN1_PCTX *pctx)
{
if (X509_NAME_print_ex(out, (X509_NAME *)*pval,
indent, pctx->nm_flags) <= 0)
return 0;
return 2;
}
/*
* This function generates the canonical encoding of the Name structure. In
* it all strings are converted to UTF8, leading, trailing and multiple
* spaces collapsed, converted to lower case and the leading SEQUENCE header
* removed. In future we could also normalize the UTF8 too. By doing this
* comparison of Name structures can be rapidly perfomed by just using
* memcmp() of the canonical encoding. By omitting the leading SEQUENCE name
* constraints of type dirName can also be checked with a simple memcmp().
*/
static int x509_name_canon(X509_NAME *a)
{
unsigned char *p;
STACK_OF(STACK_OF_X509_NAME_ENTRY) *intname = NULL;
STACK_OF(X509_NAME_ENTRY) *entries = NULL;
X509_NAME_ENTRY *entry, *tmpentry = NULL;
int set = -1, ret = 0;
size_t i;
if (a->canon_enc) {
OPENSSL_free(a->canon_enc);
a->canon_enc = NULL;
}
/* Special case: empty X509_NAME => null encoding */
if (sk_X509_NAME_ENTRY_num(a->entries) == 0) {
a->canon_enclen = 0;
return 1;
}
intname = sk_STACK_OF_X509_NAME_ENTRY_new_null();
if (!intname)
goto err;
for (i = 0; i < sk_X509_NAME_ENTRY_num(a->entries); i++) {
entry = sk_X509_NAME_ENTRY_value(a->entries, i);
if (entry->set != set) {
entries = sk_X509_NAME_ENTRY_new_null();
if (!entries)
goto err;
if (!sk_STACK_OF_X509_NAME_ENTRY_push(intname, entries)) {
sk_X509_NAME_ENTRY_free(entries);
goto err;
}
set = entry->set;
}
tmpentry = X509_NAME_ENTRY_new();
if (tmpentry == NULL)
goto err;
tmpentry->object = OBJ_dup(entry->object);
if (!asn1_string_canon(tmpentry->value, entry->value))
goto err;
if (!sk_X509_NAME_ENTRY_push(entries, tmpentry))
goto err;
tmpentry = NULL;
}
/* Finally generate encoding */
a->canon_enclen = i2d_name_canon(intname, NULL);
p = OPENSSL_malloc(a->canon_enclen);
if (!p)
goto err;
a->canon_enc = p;
i2d_name_canon(intname, &p);
ret = 1;
err:
if (tmpentry)
X509_NAME_ENTRY_free(tmpentry);
if (intname)
sk_STACK_OF_X509_NAME_ENTRY_pop_free(intname,
local_sk_X509_NAME_ENTRY_pop_free);
return ret;
}
/* Bitmap of all the types of string that will be canonicalized. */
#define ASN1_MASK_CANON \
(B_ASN1_UTF8STRING | B_ASN1_BMPSTRING | B_ASN1_UNIVERSALSTRING \
| B_ASN1_PRINTABLESTRING | B_ASN1_T61STRING | B_ASN1_IA5STRING \
| B_ASN1_VISIBLESTRING)
static int asn1_string_canon(ASN1_STRING *out, ASN1_STRING *in)
{
unsigned char *to, *from;
int len, i;
/* If type not in bitmask just copy string across */
if (!(ASN1_tag2bit(in->type) & ASN1_MASK_CANON)) {
if (!ASN1_STRING_copy(out, in))
return 0;
return 1;
}
out->type = V_ASN1_UTF8STRING;
out->length = ASN1_STRING_to_UTF8(&out->data, in);
if (out->length == -1)
return 0;
to = out->data;
from = to;
len = out->length;
/*
* Convert string in place to canonical form. Ultimately we may need to
* handle a wider range of characters but for now ignore anything with
* MSB set and rely on the isspace() and tolower() functions.
*/
/* Ignore leading spaces */
while ((len > 0) && !(*from & 0x80) && isspace(*from)) {
from++;
len--;
}
to = from + len - 1;
/* Ignore trailing spaces */
while ((len > 0) && !(*to & 0x80) && isspace(*to)) {
to--;
len--;
}
to = out->data;
i = 0;
while (i < len) {
/* If MSB set just copy across */
if (*from & 0x80) {
*to++ = *from++;
i++;
}
/* Collapse multiple spaces */
else if (isspace(*from)) {
/* Copy one space across */
*to++ = ' ';
/*
* Ignore subsequent spaces. Note: don't need to check len here
* because we know the last character is a non-space so we can't
* overflow.
*/
do {
from++;
i++;
}
while (!(*from & 0x80) && isspace(*from));
} else {
*to++ = tolower(*from);
from++;
i++;
}
}
out->length = to - out->data;
return 1;
}
static int i2d_name_canon(STACK_OF(STACK_OF_X509_NAME_ENTRY) * _intname,
unsigned char **in)
{
int len, ltmp;
size_t i;
ASN1_VALUE *v;
STACK_OF(ASN1_VALUE) *intname = (STACK_OF(ASN1_VALUE) *)_intname;
len = 0;
for (i = 0; i < sk_ASN1_VALUE_num(intname); i++) {
v = sk_ASN1_VALUE_value(intname, i);
ltmp = ASN1_item_ex_i2d(&v, in,
ASN1_ITEM_rptr(X509_NAME_ENTRIES), -1, -1);
if (ltmp < 0)
return ltmp;
len += ltmp;
}
return len;
}
int X509_NAME_set(X509_NAME **xn, X509_NAME *name)
{
X509_NAME *in;
if (!xn || !name)
return (0);
if (*xn != name) {
in = X509_NAME_dup(name);
if (in != NULL) {
X509_NAME_free(*xn);
*xn = in;
}
}
return (*xn != NULL);
}
IMPLEMENT_ASN1_SET_OF(X509_NAME_ENTRY)