On Fri, Aug 06, 2021 at 04:02:12PM +0900, Masahisa Kojima wrote:
> TCG PC Client PFP spec requires to measure "Boot####"
> and "BootOrder" variables, EV_SEPARATOR event prior
> to the Ready to Boot invocation.
> Since u-boot does not implement Ready to Boot event,
> these measurements are performed when efi_start_image() is called.
>
> TCG spec also requires to measure "Calling EFI Application from
> Boot Option" for each boot attempt, and "Returning from EFI
> Application from Boot Option" if a boot device returns control
> back to the Boot Manager.
>
> Signed-off-by: Masahisa Kojima <masahisa.koj...@linaro.org>
> ---
> Changes in v3:
> - modify log output
>
> Changes in v2:
> - use efi_create_indexed_name() for "Boot####" variable
>
> include/efi_loader.h | 4 ++
> include/tpm-v2.h | 18 ++++-
> lib/efi_loader/efi_boottime.c | 20 ++++++
> lib/efi_loader/efi_tcg2.c | 121 ++++++++++++++++++++++++++++++++++
> 4 files changed, 162 insertions(+), 1 deletion(-)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index a120d94431..345cbb72c4 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -499,6 +499,10 @@ efi_status_t efi_run_image(void *source_buffer,
> efi_uintn_t source_size);
> efi_status_t efi_init_variables(void);
> /* Notify ExitBootServices() is called */
> void efi_variables_boot_exit_notify(void);
> +/* Measure efi application invocation */
> +efi_status_t EFIAPI efi_tcg2_measure_efi_app_invocation(void);
> +/* Measure efi application exit */
> +efi_status_t EFIAPI efi_tcg2_measure_efi_app_exit(void);
I don't think that we need to have EFIAPI specifiers for those functions
as they are not api's.
> /* Called by bootefi to initialize root node */
> efi_status_t efi_root_node_register(void);
> /* Called by bootefi to initialize runtime */
> diff --git a/include/tpm-v2.h b/include/tpm-v2.h
> index 247b386967..325c73006e 100644
> --- a/include/tpm-v2.h
> +++ b/include/tpm-v2.h
> @@ -73,7 +73,7 @@ struct udevice;
> /*
> * event types, cf.
> * "TCG PC Client Platform Firmware Profile Specification", Family "2.0"
> - * rev 1.04, June 3, 2019
> + * Level 00 Version 1.05 Revision 23, May 7, 2021
> */
> #define EV_EFI_EVENT_BASE ((u32)0x80000000)
> #define EV_EFI_VARIABLE_DRIVER_CONFIG ((u32)0x80000001)
> @@ -85,8 +85,24 @@ struct udevice;
> #define EV_EFI_ACTION ((u32)0x80000007)
> #define EV_EFI_PLATFORM_FIRMWARE_BLOB ((u32)0x80000008)
> #define EV_EFI_HANDOFF_TABLES ((u32)0x80000009)
> +#define EV_EFI_PLATFORM_FIRMWARE_BLOB2 ((u32)0x8000000A)
> +#define EV_EFI_HANDOFF_TABLES2 ((u32)0x8000000B)
> +#define EV_EFI_VARIABLE_BOOT2 ((u32)0x8000000C)
> #define EV_EFI_HCRTM_EVENT ((u32)0x80000010)
> #define EV_EFI_VARIABLE_AUTHORITY ((u32)0x800000E0)
> +#define EV_EFI_SPDM_FIRMWARE_BLOB ((u32)0x800000E1)
> +#define EV_EFI_SPDM_FIRMWARE_CONFIG ((u32)0x800000E2)
> +
> +#define EFI_CALLING_EFI_APPLICATION \
> + "Calling EFI Application from Boot Option"
> +#define EFI_RETURNING_FROM_EFI_APPLICATION \
> + "Returning from EFI Application from Boot Option"
> +#define EFI_EXIT_BOOT_SERVICES_INVOCATION \
> + "Exit Boot Services Invocation"
> +#define EFI_EXIT_BOOT_SERVICES_FAILED \
> + "Exit Boot Services Returned with Failure"
> +#define EFI_EXIT_BOOT_SERVICES_SUCCEEDED \
> + "Exit Boot Services Returned with Success"
>
> /* TPMS_TAGGED_PROPERTY Structure */
> struct tpms_tagged_property {
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 0b98e91813..13ab139222 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -2994,6 +2994,16 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t
> image_handle,
> image_obj->exit_status = &exit_status;
> image_obj->exit_jmp = &exit_jmp;
>
> + if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
> + if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION) {
> + ret = efi_tcg2_measure_efi_app_invocation();
> + if (ret != EFI_SUCCESS) {
> + log_warning("tcg2 measurement fails(0x%lx)\n",
> + ret);
> + }
> + }
> + }
> +
> /* call the image! */
> if (setjmp(&exit_jmp)) {
> /*
> @@ -3252,6 +3262,16 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t
> image_handle,
> exit_status != EFI_SUCCESS)
> efi_delete_image(image_obj, loaded_image_protocol);
>
> + if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
> + if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION) {
> + ret = efi_tcg2_measure_efi_app_exit();
> + if (ret != EFI_SUCCESS) {
> + log_warning("tcg2 measurement fails(0x%lx)\n",
> + ret);
> + }
> + }
> + }
> +
> /* Make sure entry/exit counts for EFI world cross-overs match */
> EFI_EXIT(exit_status);
>
> diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
> index a2e9587cd0..7dd30c2bc9 100644
> --- a/lib/efi_loader/efi_tcg2.c
> +++ b/lib/efi_loader/efi_tcg2.c
> @@ -35,6 +35,7 @@ struct event_log_buffer {
> };
>
> static struct event_log_buffer event_log;
> +static bool tcg2_efi_app_invoked;
> /*
> * When requesting TPM2_CAP_TPM_PROPERTIES the value is on a standard offset.
> * Since the current tpm2_get_capability() response buffers starts at
> @@ -1385,6 +1386,126 @@ static efi_status_t tcg2_measure_variable(struct
> udevice *dev, u32 pcr_index,
> return ret;
> }
>
> +/**
> + * tcg2_measure_boot_variable() - measure boot variables
> + *
> + * @dev: TPM device
> + *
> + * Return: status code
> + */
> +static efi_status_t tcg2_measure_boot_variable(struct udevice *dev)
> +{
> + u16 *boot_order;
> + u16 *boot_index;
> + u16 var_name[] = L"BootOrder";
> + u16 boot_name[] = L"Boot####";
> + u8 *bootvar;
> + efi_uintn_t var_data_size;
> + u32 count, i;
> + efi_status_t ret;
> +
> + boot_order = efi_get_var(var_name, &efi_global_variable_guid,
> + &var_data_size);
> + if (!boot_order) {
> + ret = EFI_NOT_FOUND;
> + goto error;
> + }
What if BootOrder is not defined, but BootNext is defined?
-Takahiro Akashi
> +
> + ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2, var_name,
> + &efi_global_variable_guid, var_data_size,
> + (u8 *)boot_order);
> + if (ret != EFI_SUCCESS)
> + goto error;
> +
> + count = var_data_size / sizeof(*boot_order);
> + boot_index = boot_order;
> + for (i = 0; i < count; i++) {
> + efi_create_indexed_name(boot_name, sizeof(boot_name),
> + "Boot", *boot_index++);
> +
> + bootvar = efi_get_var(boot_name, &efi_global_variable_guid,
> + &var_data_size);
> +
> + if (!bootvar) {
> + log_info("%ls not found\n", boot_name);
> + continue;
> + }
> +
> + ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2,
> + boot_name,
> + &efi_global_variable_guid,
> + var_data_size, bootvar);
> + free(bootvar);
> + if (ret != EFI_SUCCESS)
> + goto error;
> + }
> +
> +error:
> + free(boot_order);
> + return ret;
> +}
> +
> +/**
> + * efi_tcg2_measure_efi_app_invocation() - measure efi app invocation
> + *
> + * Return: status code
> + */
> +efi_status_t EFIAPI efi_tcg2_measure_efi_app_invocation(void)
> +{
> + efi_status_t ret;
> + u32 pcr_index;
> + struct udevice *dev;
> + u32 event = 0;
> +
> + if (tcg2_efi_app_invoked)
> + return EFI_SUCCESS;
> +
> + ret = platform_get_tpm2_device(&dev);
> + if (ret != EFI_SUCCESS)
> + return ret;
> +
> + ret = tcg2_measure_boot_variable(dev);
> + if (ret != EFI_SUCCESS)
> + goto out;
> +
> + ret = tcg2_measure_event(dev, 4, EV_EFI_ACTION,
> + strlen(EFI_CALLING_EFI_APPLICATION),
> + (u8 *)EFI_CALLING_EFI_APPLICATION);
> + if (ret != EFI_SUCCESS)
> + goto out;
> +
> + for (pcr_index = 0; pcr_index <= 7; pcr_index++) {
> + ret = tcg2_measure_event(dev, pcr_index, EV_SEPARATOR,
> + sizeof(event), (u8 *)&event);
> + if (ret != EFI_SUCCESS)
> + goto out;
> + }
> +
> + tcg2_efi_app_invoked = true;
> +out:
> + return ret;
> +}
> +
> +/**
> + * efi_tcg2_measure_efi_app_exit() - measure efi app exit
> + *
> + * Return: status code
> + */
> +efi_status_t EFIAPI efi_tcg2_measure_efi_app_exit(void)
> +{
> + efi_status_t ret;
> + struct udevice *dev;
> +
> + ret = platform_get_tpm2_device(&dev);
> + if (ret != EFI_SUCCESS)
> + return ret;
> +
> + ret = tcg2_measure_event(dev, 4, EV_EFI_ACTION,
> + strlen(EFI_RETURNING_FROM_EFI_APPLICATION),
> + (u8 *)EFI_RETURNING_FROM_EFI_APPLICATION);
> + return ret;
> +}
> +
> /**
> * tcg2_measure_secure_boot_variable() - measure secure boot variables
> *
> --
> 2.17.1
>
