1
0
mirror of https://git.code.sf.net/p/linux-ima/ima-evm-utils synced 2025-07-03 06:03:16 +02:00
Files
ima-evm-utils-mirror/src/pcr_tsspcrread.c
Petr Vorel 80d3fda608 ima-evm-utils: Check for tsspcrread in runtime
instead of checking in build time as it's runtime dependency.
Also log when tsspcrread not found to make debugging easier.

We search for tsspcrread unless there is tss2-esys with Esys_PCR_Read(),
thus pcr_none.c was dropped as unneeded.

file_exist(), tst_get_path() and MIN() taken from LTP project.

Signed-off-by: Petr Vorel <pvorel@suse.cz>
[zohar@linux.ibm.com: added USE_FPRINTF definitions]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-15 21:49:26 -04:00

112 lines
3.2 KiB
C

/*
* ima-evm-utils - IMA/EVM support utilities
*
* Copyright (C) 2011 Nokia Corporation
* Copyright (C) 2011,2012,2013 Intel Corporation
* Copyright (C) 2013,2014 Samsung Electronics
*
* Authors:
* Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
* <dmitry.kasatkin@intel.com>
* <d.kasatkin@samsung.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU General Public License in all respects
* for all of the code used other than as permitted herein. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you do not
* wish to do so, delete this exception statement from your version. If you
* delete this exception statement from all source files in the program,
* then also delete it in the license file.
*
* File: pcr_tsspcrread.c
* PCR reading implementation based on IBM TSS2
*/
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <openssl/sha.h>
#define USE_FPRINTF
#include "utils.h"
#include "imaevm.h"
#define CMD "tsspcrread"
static char path[PATH_MAX];
int tpm2_pcr_supported(void)
{
if (imaevm_params.verbose > LOG_INFO)
log_info("Using %s to read PCRs.\n", CMD);
if (get_cmd_path(CMD, path, sizeof(path))) {
log_debug("Couldn't find '%s' in $PATH", CMD);
return 0;
}
log_debug("Found '%s' in $PATH", CMD);
return 1;
}
int tpm2_pcr_read(const char *algo_name, int idx, uint8_t *hwpcr,
int len, char **errmsg)
{
FILE *fp;
char pcr[100]; /* may contain an error */
char cmd[PATH_MAX + 50];
int ret;
sprintf(cmd, "%s -halg %s -ha %d -ns 2> /dev/null",
path, algo_name, idx);
fp = popen(cmd, "r");
if (!fp) {
ret = asprintf(errmsg, "popen failed: %s", strerror(errno));
if (ret == -1) /* the contents of errmsg is undefined */
*errmsg = NULL;
return -1;
}
if (fgets(pcr, sizeof(pcr), fp) == NULL) {
ret = asprintf(errmsg, "tsspcrread failed: %s",
strerror(errno));
if (ret == -1) /* the contents of errmsg is undefined */
*errmsg = NULL;
ret = pclose(fp);
return -1;
}
/* get the popen "cmd" return code */
ret = pclose(fp);
/* Treat an unallocated bank as an error */
if (!ret && (strlen(pcr) < SHA_DIGEST_LENGTH))
ret = -1;
if (!ret)
hex2bin(hwpcr, pcr, len);
else
*errmsg = strndup(pcr, strlen(pcr) - 1); /* remove newline */
return ret;
}