On Mon, 27 Jan 2025 at 16:59, Raymond Mao raymond.mao@linaro.org wrote:
Add PCR allocate wrapper APIs for using in tcg2 protocol. The wrapper proceeds a PCR allocate command, followed by a shutdown command. A system boot is required after two commands since TPM device needs a HW reset to activate the new algorithms config. Also, a helper function is included to determine the new bank mask for PCR allocation by combining the status of current active, supported and eventlog bank masks. A new kconfig is created. PCR allocate and system reboot only happens when the kconfig is selected, otherwise just exit with errors.
Signed-off-by: Raymond Mao raymond.mao@linaro.org
changes in v2
- Rename the newly added APIs.
changes in v3
- Rename tpm2_set_algorithm_mask to tpm2_scan_masks.
include/tpm-v2.h | 21 ++++++++ lib/Kconfig | 12 +++++ lib/tpm-v2.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 154 insertions(+)
diff --git a/include/tpm-v2.h b/include/tpm-v2.h index af3158f6e4..ece422df0c 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -703,6 +703,18 @@ u32 tpm2_report_state(struct udevice *dev, uint vendor_cmd, uint vendor_subcmd, u32 tpm2_enable_nvcommits(struct udevice *dev, uint vendor_cmd, uint vendor_subcmd);
+/**
- tpm2_scan_masks - Scan the bitmask of algorithms based on the
active/supported banks and the one from eventlog.
- @dev TPM device
- @log_active Active algorithm bitmask
- @mask Bitmask to set
- Return: zero on success, negative errno otherwise
- */
+int tpm2_scan_masks(struct udevice *dev, u32 log_active, u32 *mask);
/**
- tpm2_pcr_config_algo() - Allocate the active PCRs. Requires reboot
@@ -730,6 +742,15 @@ u32 tpm2_pcr_config_algo(struct udevice *dev, u32 algo_mask, u32 tpm2_send_pcr_allocate(struct udevice *dev, const char *pw, const ssize_t pw_sz, struct tpml_pcr_selection *pcr, u32 pcr_len); +/**
- tpm2_activate_banks() - Activate PCR banks
- @param dev TPM device
- @log_active Bitmask of eventlog algorithms
- Return: code of the operation
- */
+int tpm2_activate_banks(struct udevice *dev, u32 log_active);
/**
- tpm2_auto_start() - start up the TPM and perform selftests.
diff --git a/lib/Kconfig b/lib/Kconfig index baeb615626..0732333849 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -514,6 +514,18 @@ config VPL_TPM for the low-level TPM interface, but only one TPM is supported at a time by the TPM library.
+config TPM_PCR_ALLOCATE
bool "Re-configurate TPM algorithms in run-time (PCR allocate)"depends on TPM_V2 && (MEASURED_BOOT || EFI_TCG2_PROTOCOL)helpThis enables a detection for the dismatches of algorithms among TPMdevice, eventlog from previous boot stage and U-Boot support.A PCR allocate command will be sent to reconfigurate the TPM devicein run-time to make sure algorithms in TPM device, eventlog andU-Boot are aligned with each other.A system reboot will be proceeded after then to activate the newalgorithms.endmenu
menu "Android Verified Boot" diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index 045b5dd9eb..aa02a9e961 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -44,6 +44,127 @@ static int tpm2_update_active_banks(struct udevice *dev) return 0; }
+static void tpm2_print_selected_algorithm_name(u32 selected) +{
size_t i;const char *str;for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) {const struct digest_info *algo = &hash_algo_list[i];if (!(selected & algo->hash_mask))continue;str = tpm2_algorithm_name(algo->hash_alg);if (str)log_info("%s\n", str);}+}
+int tpm2_scan_masks(struct udevice *dev, u32 log_active, u32 *mask) +{
struct tpml_pcr_selection pcrs;u32 active = 0;u32 supported = 0;int rc, i;*mask = 0;rc = tpm2_get_pcr_info(dev, &pcrs);if (rc)return rc;for (i = 0; i < pcrs.count; i++) {struct tpms_pcr_selection *sel = &pcrs.selection[i];size_t j;u32 hash_mask = 0;for (j = 0; j < ARRAY_SIZE(hash_algo_list); j++) {if (hash_algo_list[j].hash_alg == sel->hash)hash_mask = hash_algo_list[j].hash_mask;}if (tpm2_algorithm_supported(sel->hash))supported |= hash_mask;if (tpm2_is_active_bank(sel))active |= hash_mask;}/* All eventlog algorithm(s) must be supported */if (log_active & ~supported) {log_err("EventLog contains U-Boot unsupported algorithm(s)\n");tpm2_print_selected_algorithm_name(log_active & ~supported);rc = -1;}if (log_active && active & ~log_active) {log_warning("TPM active algorithm(s) not exist in eventlog\n");tpm2_print_selected_algorithm_name(active & ~log_active);*mask = log_active;}/* Any active algorithm(s) which are not supported must be removed */if (active & ~supported) {log_warning("TPM active algorithm(s) unsupported by u-boot\n");tpm2_print_selected_algorithm_name(active & ~supported);if (*mask)*mask = active & supported & *mask;else*mask = active & supported;}return rc;+}
+static int tpm2_pcr_allocate(struct udevice *dev, u32 algo_mask) +{
struct tpml_pcr_selection pcr = { 0 };u32 pcr_len = 0;int rc;rc = tpm2_get_pcr_info(dev, &pcr);if (rc)return rc;rc = tpm2_pcr_config_algo(dev, algo_mask, &pcr, &pcr_len);if (rc)return rc;/* Assume no password */rc = tpm2_send_pcr_allocate(dev, NULL, 0, &pcr, pcr_len);if (rc)return rc;/* Send TPM2_Shutdown, assume mode = TPM2_SU_CLEAR */return tpm2_startup(dev, false, TPM2_SU_CLEAR);+}
+int tpm2_activate_banks(struct udevice *dev, u32 log_active) +{
u32 algo_mask = 0;int rc;rc = tpm2_scan_masks(dev, log_active, &algo_mask);if (rc)return rc;if (algo_mask) {if (!IS_ENABLED(CONFIG_TPM_PCR_ALLOCATE))return -1;rc = tpm2_pcr_allocate(dev, algo_mask);if (rc)return rc;log_info("PCR allocate done, shutdown TPM and reboot\n");do_reset(NULL, 0, 0, NULL);log_err("reset does not work!\n");return -1;}return 0;+}
u32 tpm2_startup(struct udevice *dev, bool bon, enum tpm2_startup_types mode) { int op = bon ? TPM2_CC_STARTUP : TPM2_CC_SHUTDOWN; -- 2.25.1
Reviewed-by: Ilias Apalodimas ilias.apalodimas@linaro.org