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/*
* sbios_elt.c: SBIOS policy element (LCP_SBIOS_ELEMENT) plugin
*
* Copyright (c) 2014, Intel Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of the Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER 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.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#define _GNU_SOURCE
#include <getopt.h>
#include <safe_lib.h>
#define PRINT printf
#include "../include/config.h"
#include "../include/hash.h"
#include "../include/uuid.h"
#include "../include/lcp3.h"
#include "polelt_plugin.h"
#include "lcputils.h"
#define MAX_HASHES 33 /* +1 for fallback_hash */
static unsigned int nr_hashes;
static tb_hash_t hashes[MAX_HASHES];
static char alg_name[32] = "sha1";
static uint16_t alg_type = TPM_ALG_SHA1;
static uint16_t *get_num_hashes(lcp_sbios_element_t2 *sbios)
{
/* because fallback_hash is variable size, need to calculate this */
return (void *)&sbios->fallback_hash + get_hash_size(sbios->hash_alg) +
sizeof(sbios->reserved2);
}
static lcp_hash_t2 *get_hashes(lcp_sbios_element_t2 *sbios)
{
/* because fallback_hash is variable size, need to calculate this */
return (void *)get_num_hashes(sbios) + sizeof(sbios->num_hashes);
}
static bool parse_sbios_line(const char *line)
{
if ( nr_hashes == MAX_HASHES )
return false;
return parse_line_hashes(line, &hashes[nr_hashes++], alg_type);
}
static bool cmdline_handler(int c, const char *opt)
{
if (c == 'a') {
strlcpy(alg_name, opt,sizeof(alg_name));
alg_type = str_to_hash_alg(alg_name);
LOG("cmdline opt: hash alg: %s\n",alg_name);
return true;
}
else if ( c != 0 ) {
ERROR("Error: unknown option for sbios type\n");
return false;
}
/* BIOS hash files */
LOG("cmdline opt: sbios hash file: %s\n", opt);
if ( !parse_file(opt, parse_sbios_line) )
return false;
if ( nr_hashes == 0 ) {
ERROR("Error: no hashes provided\n");
return false;
}
return true;
}
static lcp_policy_element_t *create(void)
{
LOG("[create]\n");
/* take entire struct size and subtract size of fallback_hash because
sizeof(lcp_hash_t) is not accurate (hence get_hash_size()), then
add it back in w/ 'nr_hashes' */
size_t data_size = sizeof(lcp_sbios_element_t2) - sizeof(lcp_hash_t2) +
nr_hashes * get_hash_size(alg_type);
lcp_policy_element_t *elt = malloc(sizeof(*elt) + data_size);
if ( elt == NULL ) {
ERROR("Error: failed to allocate element\n");
return NULL;
}
memset_s(elt, sizeof(*elt) + data_size, 0);
elt->size = sizeof(*elt) + data_size;
lcp_sbios_element_t2 *sbios = (lcp_sbios_element_t2 *)&elt->data;
sbios->hash_alg = alg_type;
memcpy_s(&sbios->fallback_hash, get_hash_size(alg_type), &hashes[0], get_hash_size(alg_type));
*get_num_hashes(sbios) = nr_hashes - 1;
lcp_hash_t2 *hash = get_hashes(sbios);
for ( unsigned int i = 1; i < nr_hashes; i++ ) {
memcpy_s(hash, get_hash_size(alg_type), &hashes[i], get_hash_size(alg_type));
hash = (void *)hash + get_hash_size(alg_type);
}
LOG("create SBIOS element succeed!\n");
return elt;
}
static void display(const char *prefix, const lcp_policy_element_t *elt)
{
lcp_sbios_element_t2 *sbios = (lcp_sbios_element_t2 *)elt->data;
unsigned int hash_size = get_lcp_hash_size(sbios->hash_alg);
DISPLAY("%s hash_alg: %s\n", prefix, hash_alg_to_str(sbios->hash_alg));
DISPLAY("%s fallback_hash: ", prefix);
print_hex("", (tb_hash_t *)&sbios->fallback_hash, hash_size);
DISPLAY("%s num_hashes: %u\n", prefix, *get_num_hashes(sbios));
uint8_t *hash = (uint8_t *)get_hashes(sbios);
for ( unsigned int i = 0; i < *get_num_hashes(sbios); i++ ) {
DISPLAY("%s hashes[%u]: ", prefix, i);
print_hex("", hash, hash_size);
hash += hash_size;
}
}
static struct option opts[] = {
{"alg", required_argument, NULL, 'a'},
{0, 0, 0, 0}
};
static polelt_plugin_t plugin = {
"sbios",
opts,
" sbios\n"
" [--alg <sha1|sha256|sha384|sha512>] hash alg of element\n"
" <FILE1> [FILE2] ... one or more files containing BIOS\n"
" hash(es); each file can contain\n"
" multiple hashes; the first hash in\n"
" the first file will be the fallback\n"
" hash\n",
LCP_POLELT_TYPE_SBIOS2,
&cmdline_handler,
&create,
&display
};
REG_POLELT_PLUGIN(&plugin)
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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