tpm: measure DTB in PCR1 instead of PCR0

The PC client spec [0], doesn't describe measurements for DTBs. It does
describe what do to for ACPI tables though.

There is a description for ACPI in 3.3.4.1 PCR[0] – SRTM, POST BIOS,
and Embedded Drivers and they explicitly mention ACPI in there. There's
no mention of ACPI in 3.3.4.2 PCR[1] – Host Platform Configuration.

However, in Figure 6 --  PCR Mapping of UEFI Components ACPI is shown
in PCR1. The general description also mentions PCR0 is for code and PCR1
is for data such as ACPI and SMBIOS.

So let's switch over the DTB measurements to PCR1 which seems a better
fit.

[0] https://trustedcomputinggroup.org/resource/pc-client-specific-platform-firmware-profile-specification

Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Eddie James <eajames@linux.ibm.com>

diff --git a/boot/bootm.c b/boot/bootm.c
index 032f5a4..9879e1b 100644 (file)
--- a/boot/bootm.c
+++ b/boot/bootm.c
@@ -964,7 +964,7 @@ int bootm_measure(struct bootm_headers *images)
                        goto unmap_initrd;
 
                if (IS_ENABLED(CONFIG_MEASURE_DEVICETREE)) {
-                       ret = tcg2_measure_data(dev, &elog, 0, images->ft_len,
+                       ret = tcg2_measure_data(dev, &elog, 1, images->ft_len,
                                                (u8 *)images->ft_addr,
                                                EV_TABLE_OF_DEVICES,
                                                strlen("dts") + 1,

diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index 945aafb..d56bd56 100644 (file)
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -1331,7 +1331,7 @@ efi_status_t efi_tcg2_measure_dtb(void *dtb)
        sha256_update(&hash_ctx, (u8 *)dtb + fdt_off_mem_rsvmap(dtb), rsvmap_size);
        sha256_finish(&hash_ctx, blob->data + blob->blob_description_size);
 
-       ret = measure_event(dev, 0, EV_POST_CODE, event_size, (u8 *)blob);
+       ret = measure_event(dev, 1, EV_POST_CODE, event_size, (u8 *)blob);
 
        free(blob);
        return ret;