[PATCH 2/3] efi_loader: add UEFI GPT measurement
Masahisa Kojima
masahisa.kojima at linaro.org
Thu Sep 16 10:32:55 CEST 2021
On Thu, 16 Sept 2021 at 16:29, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
>
>
> On 9/15/21 7:15 AM, Masahisa Kojima wrote:
> > This commit adds the UEFI GPT disk partition topology
> > measurement required in TCG PC Client PFP Spec.
>
> Thanks for looking into the missing parts of TCG measurement in U-Boot.
>
> The requirements in the TCG PC Client PFP Spec are strange. It does not
> explicitly say how to handle multiple block devices. Did the authors
> never enjoy the pleasure of a second disk drive?
Yes, I had same question of this GPT measurement required in TCG spec.
I refer EDK2 implementation, GPT is measured only once[*1].
[*1] https://github.com/tianocore/edk2/blob/master/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLib.c#L46
>
> With your implementation you would measure the GPT table of the SD-card
> from which you load Shim or GRUB but would not care about the GPT of the
> NVMe drive with your OS.
>
> A clarification by the TCG standards committee would be helpful.
We need to find the right person to access.
>
> After this series "10.2.7 DEVICE_SECURITY_EVENT_DATA Structure" still
> needs to be covered.
I'm trying to cover all "MUST" and non-platform specific requirement,
and this is completed with this patch series.
DEVICE_SECURITY_EVENT_DATA is "should" requirement.
In addition, DEVICE_SECURITY_EVENT_DATA is not implemented
in EDK2(but it is not the reason u-boot will not support this event anyway).
Thanks,
Masahisa Kojima
>
> Best regards
>
> Heinrich
>
> >
> > Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> > ---
> > include/blk.h | 3 +
> > include/efi_loader.h | 2 +-
> > include/efi_tcg2.h | 12 +++
> > lib/efi_loader/efi_boottime.c | 2 +-
> > lib/efi_loader/efi_tcg2.c | 175 +++++++++++++++++++++++++++++++++-
> > 5 files changed, 191 insertions(+), 3 deletions(-)
> >
> > diff --git a/include/blk.h b/include/blk.h
> > index 19bab081c2..f0cc7ca1a2 100644
> > --- a/include/blk.h
> > +++ b/include/blk.h
> > @@ -45,6 +45,9 @@ enum if_type {
> > #define BLK_PRD_SIZE 20
> > #define BLK_REV_SIZE 8
> >
> > +#define PART_FORMAT_PCAT 0x1
> > +#define PART_FORMAT_GPT 0x2
> > +
> > /*
> > * Identifies the partition table type (ie. MBR vs GPT GUID) signature
> > */
> > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > index 13f0c24058..dbcc296e01 100644
> > --- a/include/efi_loader.h
> > +++ b/include/efi_loader.h
> > @@ -503,7 +503,7 @@ efi_status_t efi_init_variables(void);
> > void efi_variables_boot_exit_notify(void);
> > efi_status_t efi_tcg2_notify_exit_boot_services_failed(void);
> > /* Measure efi application invocation */
> > -efi_status_t efi_tcg2_measure_efi_app_invocation(void);
> > +efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *handle);
> > /* Measure efi application exit */
> > efi_status_t efi_tcg2_measure_efi_app_exit(void);
> > /* Called by bootefi to initialize root node */
> > diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h
> > index da33f8a1d0..33257fa96b 100644
> > --- a/include/efi_tcg2.h
> > +++ b/include/efi_tcg2.h
> > @@ -230,6 +230,18 @@ struct smbios_handoff_table_pointers2 {
> > struct efi_configuration_table table_entry[1];
> > } __packed;
> >
> > +/**
> > + * struct tdUEFI_GPT_DATA - event log structure of industry standard tables
> > + * @uefi_partition_header: gpt partition header
> > + * @number_of_partitions: the number of partition
> > + * @partitions: partition entries
> > + */
> > +struct efi_gpt_data {
> > + gpt_header uefi_partition_header;
> > + u64 number_of_partitions;
> > + gpt_entry partitions[];
> > +} __packed;
> > +
> > struct efi_tcg2_protocol {
> > efi_status_t (EFIAPI * get_capability)(struct efi_tcg2_protocol *this,
> > struct efi_tcg2_boot_service_capability *capability);
> > diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> > index 701e2212c8..bf5661e1ee 100644
> > --- a/lib/efi_loader/efi_boottime.c
> > +++ b/lib/efi_loader/efi_boottime.c
> > @@ -3003,7 +3003,7 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
> >
> > if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
> > if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION) {
> > - ret = efi_tcg2_measure_efi_app_invocation();
> > + ret = efi_tcg2_measure_efi_app_invocation(image_obj);
> > if (ret != EFI_SUCCESS) {
> > log_warning("tcg2 measurement fails(0x%lx)\n",
> > ret);
> > diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
> > index 7f47998a55..35810615ed 100644
> > --- a/lib/efi_loader/efi_tcg2.c
> > +++ b/lib/efi_loader/efi_tcg2.c
> > @@ -1525,12 +1525,181 @@ static void *search_smbios_table(void)
> > return NULL;
> > }
> >
> > +/**
> > + * search_gpt_dp_node() - search gpt device path node
> > + *
> > + * @device_path: device path
> > + *
> > + * Return: pointer to the gpt device path node
> > + */
> > +static struct
> > +efi_device_path *search_gpt_dp_node(struct efi_device_path *device_path)
> > +{
> > + struct efi_device_path *dp = device_path;
> > +
> > + while (dp) {
> > + if (dp->type == DEVICE_PATH_TYPE_MEDIA_DEVICE &&
> > + dp->sub_type == DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH) {
> > + struct efi_device_path_hard_drive_path *hd_dp =
> > + (struct efi_device_path_hard_drive_path *)dp;
> > +
> > + if (hd_dp->partmap_type == PART_FORMAT_GPT &&
> > + hd_dp->signature_type == SIG_TYPE_GUID)
> > + return dp;
> > + }
> > + dp = efi_dp_next(dp);
> > + }
> > +
> > + return NULL;
> > +}
> > +
> > +/**
> > + * tcg2_measure_gpt_table() - measure gpt table
> > + *
> > + * @dev: TPM device
> > + * @loaded_image: handle to the loaded image
> > + *
> > + * Return: status code
> > + */
> > +static efi_status_t
> > +tcg2_measure_gpt_data(struct udevice *dev,
> > + struct efi_loaded_image_obj *loaded_image)
> > +{
> > + efi_status_t ret;
> > + efi_handle_t handle;
> > + struct efi_handler *dp_handler;
> > + struct efi_device_path *orig_device_path;
> > + struct efi_device_path *device_path;
> > + struct efi_device_path *dp;
> > + struct efi_block_io *block_io;
> > + struct efi_gpt_data *event = NULL;
> > + efi_guid_t null_guid = NULL_GUID;
> > + gpt_header *orig_gpt_h = NULL;
> > + gpt_entry *orig_gpt_e = NULL;
> > + gpt_header *gpt_h = NULL;
> > + gpt_entry *entry = NULL;
> > + gpt_entry *gpt_e;
> > + u32 num_of_valid_entry = 0;
> > + u32 event_size;
> > + u32 i;
> > + u32 total_gpt_entry_size;
> > +
> > + ret = efi_search_protocol(&loaded_image->header,
> > + &efi_guid_loaded_image_device_path,
> > + &dp_handler);
> > + if (ret != EFI_SUCCESS)
> > + return ret;
> > +
> > + orig_device_path = dp_handler->protocol_interface;
> > + device_path = efi_dp_dup(orig_device_path);
> > + if (!device_path)
> > + return EFI_OUT_OF_RESOURCES;
> > +
> > + dp = search_gpt_dp_node(device_path);
> > + if (!dp) {
> > + /* no GPT device path node found, skip GPT measurement */
> > + ret = EFI_SUCCESS;
> > + goto out1;
> > + }
> > +
> > + /* read GPT header */
> > + dp->type = DEVICE_PATH_TYPE_END;
> > + dp->sub_type = DEVICE_PATH_SUB_TYPE_END;
> > + dp = device_path;
> > + ret = EFI_CALL(systab.boottime->locate_device_path(&efi_block_io_guid,
> > + &dp, &handle));
> > + if (ret != EFI_SUCCESS)
> > + goto out1;
> > +
> > + ret = EFI_CALL(efi_handle_protocol(handle,
> > + &efi_block_io_guid, (void **)&block_io));
> > + if (ret != EFI_SUCCESS)
> > + goto out1;
> > +
> > + orig_gpt_h = calloc(1, (block_io->media->block_size + block_io->media->io_align));
> > + if (!orig_gpt_h) {
> > + ret = EFI_OUT_OF_RESOURCES;
> > + goto out2;
> > + }
> > +
> > + gpt_h = (gpt_header *)ALIGN((uintptr_t)orig_gpt_h, block_io->media->io_align);
> > + ret = block_io->read_blocks(block_io, block_io->media->media_id, 1,
> > + block_io->media->block_size, gpt_h);
> > + if (ret != EFI_SUCCESS)
> > + goto out2;
> > +
> > + /* read GPT entry */
> > + total_gpt_entry_size = gpt_h->num_partition_entries *
> > + gpt_h->sizeof_partition_entry;
> > + orig_gpt_e = calloc(1, total_gpt_entry_size + block_io->media->io_align);
> > + entry = (void *)ALIGN((uintptr_t)orig_gpt_e, block_io->media->io_align);
> > + if (!entry) {
> > + ret = EFI_OUT_OF_RESOURCES;
> > + goto out2;
> > + }
> > +
> > + ret = block_io->read_blocks(block_io, block_io->media->media_id,
> > + gpt_h->partition_entry_lba,
> > + total_gpt_entry_size, entry);
> > + if (ret != EFI_SUCCESS)
> > + goto out2;
> > +
> > + /* count valid GPT entry */
> > + gpt_e = entry;
> > + for (i = 0; i < gpt_h->num_partition_entries; i++) {
> > + if (guidcmp(&null_guid, &gpt_e->partition_type_guid))
> > + num_of_valid_entry++;
> > +
> > + gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry);
> > + }
> > +
> > + /* prepare event data for measurement */
> > + event_size = sizeof(struct efi_gpt_data) +
> > + (num_of_valid_entry * gpt_h->sizeof_partition_entry);
> > + event = calloc(1, event_size);
> > + if (!event) {
> > + ret = EFI_OUT_OF_RESOURCES;
> > + goto out2;
> > + }
> > + memcpy(event, gpt_h, sizeof(gpt_header));
> > + put_unaligned_le64(num_of_valid_entry, &event->number_of_partitions);
> > +
> > + /* copy valid GPT entry */
> > + gpt_e = entry;
> > + num_of_valid_entry = 0;
> > + for (i = 0; i < gpt_h->num_partition_entries; i++) {
> > + if (guidcmp(&null_guid, &gpt_e->partition_type_guid)) {
> > + memcpy((u8 *)event->partitions +
> > + (num_of_valid_entry * gpt_h->sizeof_partition_entry),
> > + gpt_e, gpt_h->sizeof_partition_entry);
> > + num_of_valid_entry++;
> > + }
> > +
> > + gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry);
> > + }
> > +
> > + ret = tcg2_measure_event(dev, 5, EV_EFI_GPT_EVENT, event_size, (u8 *)event);
> > + if (ret != EFI_SUCCESS)
> > + goto out2;
> > +
> > +out2:
> > + EFI_CALL(efi_close_protocol((efi_handle_t)block_io, &efi_block_io_guid,
> > + NULL, NULL));
> > + free(orig_gpt_h);
> > + free(orig_gpt_e);
> > + free(event);
> > +out1:
> > + efi_free_pool(device_path);
> > +
> > + return ret;
> > +}
> > +
> > /**
> > * efi_tcg2_measure_efi_app_invocation() - measure efi app invocation
> > *
> > * Return: status code
> > */
> > -efi_status_t efi_tcg2_measure_efi_app_invocation(void)
> > +efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *handle)
> > {
> > efi_status_t ret;
> > u32 pcr_index;
> > @@ -1569,6 +1738,10 @@ efi_status_t efi_tcg2_measure_efi_app_invocation(void)
> > goto out;
> > }
> >
> > + ret = tcg2_measure_gpt_data(dev, handle);
> > + if (ret != EFI_SUCCESS)
> > + goto out;
> > +
> > tcg2_efi_app_invoked = true;
> > out:
> > return ret;
> >
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