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https://git.code.sf.net/p/linux-ima/ima-evm-utils
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e52fc1d330
PCR numbers are naturally unsigned values. Further, they are 32 bits, even on 64-bit machines. This change eliminates the need for negative value and overflow tests. The parameter name is changed from j and idx to pcr_handle, which is more descriptive and is similar to the parameter name used in the TPM 2.0 specification. Signed-off-by: Ken Goldman <kgoldman@us.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
112 lines
3.2 KiB
C
112 lines
3.2 KiB
C
/*
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* ima-evm-utils - IMA/EVM support utilities
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*
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* Copyright (C) 2011 Nokia Corporation
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* Copyright (C) 2011,2012,2013 Intel Corporation
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* Copyright (C) 2013,2014 Samsung Electronics
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*
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* Authors:
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* Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
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* <dmitry.kasatkin@intel.com>
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* <d.kasatkin@samsung.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* As a special exception, the copyright holders give permission to link the
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* code of portions of this program with the OpenSSL library under certain
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* conditions as described in each individual source file and distribute
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* linked combinations including the program with the OpenSSL library. You
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* must comply with the GNU General Public License in all respects
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* for all of the code used other than as permitted herein. If you modify
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* file(s) with this exception, you may extend this exception to your
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* version of the file(s), but you are not obligated to do so. If you do not
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* wish to do so, delete this exception statement from your version. If you
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* delete this exception statement from all source files in the program,
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* then also delete it in the license file.
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*
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* File: pcr_tsspcrread.c
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* PCR reading implementation based on IBM TSS2
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*/
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#include <errno.h>
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#include <limits.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdint.h>
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#include <openssl/sha.h>
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#define USE_FPRINTF
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#include "utils.h"
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#include "imaevm.h"
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#define CMD "tsspcrread"
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static char path[PATH_MAX];
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int tpm2_pcr_supported(void)
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{
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if (imaevm_params.verbose > LOG_INFO)
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log_info("Using %s to read PCRs.\n", CMD);
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if (get_cmd_path(CMD, path, sizeof(path))) {
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log_debug("Couldn't find '%s' in $PATH\n", CMD);
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return 0;
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}
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log_debug("Found '%s' in $PATH\n", CMD);
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return 1;
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}
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int tpm2_pcr_read(const char *algo_name, uint32_t pcr_handle, uint8_t *hwpcr,
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int len, char **errmsg)
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{
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FILE *fp;
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char pcr[100]; /* may contain an error */
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char cmd[PATH_MAX + 50];
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int ret;
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sprintf(cmd, "%s -halg %s -ha %u -ns 2> /dev/null",
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path, algo_name, pcr_handle);
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fp = popen(cmd, "r");
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if (!fp) {
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ret = asprintf(errmsg, "popen failed: %s", strerror(errno));
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if (ret == -1) /* the contents of errmsg is undefined */
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*errmsg = NULL;
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return -1;
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}
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if (fgets(pcr, sizeof(pcr), fp) == NULL) {
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ret = asprintf(errmsg, "tsspcrread failed: %s",
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strerror(errno));
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if (ret == -1) /* the contents of errmsg is undefined */
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*errmsg = NULL;
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ret = pclose(fp);
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return -1;
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}
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/* get the popen "cmd" return code */
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ret = pclose(fp);
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/* Treat an unallocated bank as an error */
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if (!ret && (strlen(pcr) < SHA_DIGEST_LENGTH))
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ret = -1;
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if (!ret)
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hex2bin(hwpcr, pcr, len);
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else
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*errmsg = strndup(pcr, strlen(pcr) - 1); /* remove newline */
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return ret;
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}
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