From: Ilias Apalodimas ilias.apalodimas@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.apalodimas@linaro.org Co-developed-by: Raymond Mao raymond.mao@linaro.org Signed-off-by: Raymond Mao raymond.mao@linaro.org --- 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 4682f7664f..7ecd53106f 100644 --- a/lib/tpm_tcg2.c +++ b/lib/tpm_tcg2.c @@ -568,11 +568,36 @@ 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;