The kernel does not expose the crypto agile TPM 2.0 PCR banks to
userspace like it exposes PCRs for TPM 1.2. As a result, a userspace
application is required to read PCRs.
This patch adds tsspcrread support for reading the TPM 2.0 PCRs.
tsspcrread is one application included in the ibmtss package.
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
---
configure.ac | 3 +++
src/Makefile.am | 3 +++
src/evmctl.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++-----
3 files changed, 54 insertions(+), 5 deletions(-)
diff --git a/configure.ac b/configure.ac
index 9beb4b6c2377..40fea93fef2f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -28,6 +28,8 @@ PKG_CHECK_MODULES(LIBCRYPTO, [libcrypto >= 0.9.8 ])
AC_SUBST(KERNEL_HEADERS)
AC_CHECK_HEADER(unistd.h)
AC_CHECK_HEADERS(openssl/conf.h)
+AC_SEARCH_LIBS(TSS_Transmit, ibmtss, [have_ibmtss=yes], [have_ibmtss=no])
+AM_CONDITIONAL([CONFIG_IBMTSS], [test "x$have_ibmtss" = "xyes"])
AC_CHECK_HEADERS(sys/xattr.h, , [AC_MSG_ERROR([sys/xattr.h header not found. You need the c-library development package.])])
AC_CHECK_HEADERS(keyutils.h, , [AC_MSG_ERROR([keyutils.h header not found. You need the libkeyutils development package.])])
@@ -71,4 +73,5 @@ echo
echo "Configuration:"
echo " debug: $pkg_cv_enable_debug"
echo " openssl-conf: $enable_openssl_conf"
+echo " ibmtss: $have_ibmtss"
echo
diff --git a/src/Makefile.am b/src/Makefile.am
index 9c037e21dc4f..f0990fb01210 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -21,6 +21,9 @@ evmctl_SOURCES = evmctl.c
evmctl_CPPFLAGS = $(AM_CPPFLAGS) $(LIBCRYPTO_CFLAGS)
evmctl_LDFLAGS = $(LDFLAGS_READLINE)
evmctl_LDADD = $(LIBCRYPTO_LIBS) -lkeyutils libimaevm.la
+if CONFIG_IBMTSS
+evmctl_CFLAGS = -DIBMTSS
+endif
AM_CPPFLAGS = -I$(top_srcdir) -include config.h
diff --git a/src/evmctl.c b/src/evmctl.c
index 9e0926f10404..cbb9397be138 100644
--- a/src/evmctl.c
+++ b/src/evmctl.c
@@ -1383,10 +1383,8 @@ static int tpm_pcr_read(int idx, uint8_t *pcr, int len)
if (!fp)
fp = fopen(misc_pcrs, "r");
- if (!fp) {
- log_err("Unable to open %s or %s\n", pcrs, misc_pcrs);
+ if (!fp)
return -1;
- }
for (;;) {
p = fgets(buf, sizeof(buf), fp);
@@ -1402,6 +1400,38 @@ static int tpm_pcr_read(int idx, uint8_t *pcr, int len)
return result;
}
+#ifdef IBMTSS
+static int tpm_pcr_read2(int idx, uint8_t *hwpcr, int len, char **errmsg)
+{
+ FILE *fp;
+ char pcr[100]; /* may contain an error */
+ char cmd[36];
+ int ret = 0;
+ int i;
+
+ sprintf(cmd, "tsspcrread -halg sha1 -ha %d -ns", idx);
+ fp = popen(cmd, "r");
+ if (!fp)
+ return -1;
+
+ fgets(pcr, 100, fp);
+
+ /* pcr might contain an error message */
+ for (i = 0; i < strlen(pcr) - 1 && !ret; i++) {
+ if (isspace(pcr[i]))
+ ret = -1;
+ }
+
+ if (!ret)
+ hex2bin(hwpcr, pcr, SHA_DIGEST_LENGTH);
+ else
+ *errmsg = pcr;
+
+ pclose(fp);
+ return ret;
+}
+#endif
+
#define TCG_EVENT_NAME_LEN_MAX 255
struct template_entry {
@@ -1658,8 +1688,21 @@ static int ima_measurement(const char *file)
log_info("PCRAgg %.2d: ", i);
log_dump(pcr[i], SHA_DIGEST_LENGTH);
- if (tpm_pcr_read(i, hwpcr, sizeof(hwpcr)))
- exit(1);
+ if (tpm_pcr_read(i, hwpcr, sizeof(hwpcr))) {
+#ifdef IBMTSS
+ char *errmsg = NULL;
+
+ err = tpm_pcr_read2(i, hwpcr, sizeof(hwpcr), &errmsg);
+ if (err) {
+ log_info("Failed to read either TPM 1.2 or TPM 2.0 PCRs.\n\t %s", errmsg);
+ exit(-1);
+ }
+#else
+ log_info("Failed to read TPM 1.2 PCRs.\n");
+ exit(-1);
+#endif
+ }
+
log_info("HW PCR-%d: ", i);
log_dump(hwpcr, sizeof(hwpcr));
--
2.7.5
