From: Ilias Apalodimas <ilias.apalodi...@linaro.org>
We already check the active banks vs what U-Boot was compiled with when
trying to extend a PCR and we refuse to do so if the TPM active ones
don't match the ones U-Boot supports.
Do the same thing for the EventLog creation since extending will fail
anyway and print a message so the user can figure out the missing
algorithms.
Signed-off-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
Co-developed-by: Raymond Mao <raymond....@linaro.org>
Signed-off-by: Raymond Mao <raymond....@linaro.org>
---
Changes in v2
- None.
include/tpm-v2.h | 7 +++++++
lib/tpm-v2.c | 23 +++++++++++++++++++++++
lib/tpm_tcg2.c | 27 ++++++++++++++++++++++++++-
3 files changed, 56 insertions(+), 1 deletion(-)
diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index c49eadda26..6b3f2175b7 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -770,4 +770,11 @@ bool tpm2_check_active_banks(struct udevice *dev);
*/
bool tpm2_is_active_bank(struct tpms_pcr_selection *selection);
+/**
+ * tpm2_print_active_banks() - Print the active TPM PCRs
+ *
+ * @dev: TPM device
+ */
+void tpm2_print_active_banks(struct udevice *dev);
+
#endif /* __TPM_V2_H */
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index 96c164f2a5..bac6fd9101 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -926,3 +926,26 @@ bool tpm2_check_active_banks(struct udevice *dev)
return true;
}
+
+void tpm2_print_active_banks(struct udevice *dev)
+{
+ struct tpml_pcr_selection pcrs;
+ size_t i;
+ int rc;
+
+ rc = tpm2_get_pcr_info(dev, &pcrs);
+ if (rc) {
+ log_err("Can't retrieve active PCRs\n");
+ return;
+ }
+
+ for (i = 0; i < pcrs.count; i++) {
+ if (tpm2_is_active_bank(&pcrs.selection[i])) {
+ const char *str;
+
+ str = tpm2_algorithm_name(pcrs.selection[i].hash);
+ if (str)
+ log_info("%s\n", str);
+ }
+ }
+}
diff --git a/lib/tpm_tcg2.c b/lib/tpm_tcg2.c
index 99671804e3..e77a904129 100644
--- a/lib/tpm_tcg2.c
+++ b/lib/tpm_tcg2.c
@@ -567,11 +567,36 @@ int tcg2_log_prepare_buffer(struct udevice *dev, struct
tcg2_event_log *elog,
bool ignore_existing_log)
{
struct tcg2_event_log log;
- int rc;
+ int rc, i;
elog->log_position = 0;
elog->found = false;
+ /*
+ * Make sure U-Boot is compiled with all the active PCRs
+ * since we are about to create an EventLog and we won't
+ * measure anything if the PCR banks don't match
+ */
+ if (!tpm2_check_active_banks(dev)) {
+ log_err("Cannot create EventLog\n");
+ log_err("Mismatch between U-Boot and TPM hash algos\n");
+ log_info("TPM:\n");
+ tpm2_print_active_banks(dev);
+ log_info("U-Boot:\n");
+ for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) {
+ const struct digest_info *algo = &hash_algo_list[i];
+ const char *str;
+
+ if (!algo->supported)
+ continue;
+
+ str = tpm2_algorithm_name(algo->hash_alg);
+ if (str)
+ log_info("%s\n", str);
+ }
+ return -EINVAL;
+ }
+
rc = tcg2_platform_get_log(dev, (void **)&log.log, &log.log_size);
if (!rc) {
log.log_position = 0;
--
2.25.1
