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/*
* Copyright (C) 2003, 2004, 2005, 2007 Free Software Foundation
*
* Author: Nikos Mavrogiannopoulos
*
* This file is part of GNUTLS.
*
* The GNUTLS library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA
*
*/
/* Functions that relate to the X.509 extension parsing.
*/
#include <gnutls_int.h>
#include <gnutls_errors.h>
#include <gnutls_global.h>
#include <mpi.h>
#include <libtasn1.h>
#include <common.h>
#include <x509.h>
#include <extensions.h>
#include <gnutls_datum.h>
/* This function will attempt to return the requested extension found in
* the given X509v3 certificate. The return value is allocated and stored into
* ret.
*
* Critical will be either 0 or 1.
*
* If the extension does not exist, GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE will
* be returned.
*/
int
MHD__gnutls_x509_crt_get_extension (MHD_gnutls_x509_crt_t cert,
const char *extension_id, int indx,
MHD_gnutls_datum_t * ret,
unsigned int *_critical)
{
int k, result, len;
char name[MAX_NAME_SIZE], name2[MAX_NAME_SIZE];
char str[1024];
char str_critical[10];
int critical = 0;
char extnID[128];
MHD_gnutls_datum_t value;
int indx_counter = 0;
ret->data = NULL;
ret->size = 0;
k = 0;
do
{
k++;
snprintf (name, sizeof (name), "tbsCertificate.extensions.?%u", k);
len = sizeof (str) - 1;
result = MHD__asn1_read_value (cert->cert, name, str, &len);
/* move to next
*/
if (result == ASN1_ELEMENT_NOT_FOUND)
{
break;
}
do
{
MHD_gtls_str_cpy (name2, sizeof (name2), name);
MHD_gtls_str_cat (name2, sizeof (name2), ".extnID");
len = sizeof (extnID) - 1;
result = MHD__asn1_read_value (cert->cert, name2, extnID, &len);
if (result == ASN1_ELEMENT_NOT_FOUND)
{
MHD_gnutls_assert ();
break;
}
else if (result != ASN1_SUCCESS)
{
MHD_gnutls_assert ();
return MHD_gtls_asn2err (result);
}
/* Handle Extension
*/
if (strcmp (extnID, extension_id) == 0 && indx == indx_counter++)
{
/* extension was found
*/
/* read the critical status.
*/
MHD_gtls_str_cpy (name2, sizeof (name2), name);
MHD_gtls_str_cat (name2, sizeof (name2), ".critical");
len = sizeof (str_critical);
result =
MHD__asn1_read_value (cert->cert, name2, str_critical, &len);
if (result == ASN1_ELEMENT_NOT_FOUND)
{
MHD_gnutls_assert ();
break;
}
else if (result != ASN1_SUCCESS)
{
MHD_gnutls_assert ();
return MHD_gtls_asn2err (result);
}
if (str_critical[0] == 'T')
critical = 1;
else
critical = 0;
/* read the value.
*/
MHD_gtls_str_cpy (name2, sizeof (name2), name);
MHD_gtls_str_cat (name2, sizeof (name2), ".extnValue");
result =
MHD__gnutls_x509_read_value (cert->cert, name2, &value, 0);
if (result < 0)
{
MHD_gnutls_assert ();
return result;
}
ret->data = value.data;
ret->size = value.size;
if (_critical)
*_critical = critical;
return 0;
}
}
while (0);
}
while (1);
if (result == ASN1_ELEMENT_NOT_FOUND)
{
return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;
}
else
{
MHD_gnutls_assert ();
return MHD_gtls_asn2err (result);
}
}
/* Here we only extract the KeyUsage field, from the DER encoded
* extension.
*/
int
MHD__gnutls_x509_ext_extract_keyUsage (uint16_t * keyUsage,
opaque * extnValue, int extnValueLen)
{
ASN1_TYPE ext = ASN1_TYPE_EMPTY;
int len, result;
uint8_t str[2];
str[0] = str[1] = 0;
*keyUsage = 0;
if ((result = MHD__asn1_create_element
(MHD__gnutls_get_pkix (), "PKIX1.KeyUsage", &ext)) != ASN1_SUCCESS)
{
MHD_gnutls_assert ();
return MHD_gtls_asn2err (result);
}
result = MHD__asn1_der_decoding (&ext, extnValue, extnValueLen, NULL);
if (result != ASN1_SUCCESS)
{
MHD_gnutls_assert ();
MHD__asn1_delete_structure (&ext);
return MHD_gtls_asn2err (result);
}
len = sizeof (str);
result = MHD__asn1_read_value (ext, "", str, &len);
if (result != ASN1_SUCCESS)
{
MHD_gnutls_assert ();
MHD__asn1_delete_structure (&ext);
return 0;
}
*keyUsage = str[0] | (str[1] << 8);
MHD__asn1_delete_structure (&ext);
return 0;
}
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