From 7ee057c700dd3481eae9a4b3ee13831798fe8ea5 Mon Sep 17 00:00:00 2001 From: Vadim Bendebury Date: Sun, 3 Jul 2016 15:24:23 -0700 Subject: tpm2: use pcr0 dependent nvram space policy definitions The TPM2 specification allows defining NV ram spaces in a manner that makes it impossible to remove the space until a certain PCR is in a certain state. This comes in handy when defining spaces for rollback counters: make their removal depend on PCR0 being in the default state. Then extend PCR0 to any value. This guarantees that the spaces can not be deleted. Also, there is no need t create firmware and kernel rollback spaces with different privileges: they both can be created with the same set of properties, the firmware space could be locked by the RO firmware, and the kernel space could be locked by the RW firmware thus providing necessary privilege levels. BRANCH=none BUG=chrome-os-partner:50645, chrome-os-partner:55063 TEST=with the rest of the patches applied it is possible to boot into Chrome OS maintaining two rollback counter spaces in the TPM NV ram locked at different phases of the boot process. Change-Id: I889b2c4c4831ae01c093f33c09b4d98a11d758da Signed-off-by: Martin Roth Original-Commit-Id: 36317f5e85107b1b2e732a5bb2a38295120560cd Original-Change-Id: I69e5ada65a5f15a8c04be9def92a8e1f4b753d9a Original-Signed-off-by: Vadim Bendebury Original-Reviewed-on: https://chromium-review.googlesource.com/358094 Original-Reviewed-by: Aaron Durbin Original-Reviewed-by: Julius Werner Reviewed-on: https://review.coreboot.org/15635 Tested-by: build bot (Jenkins) Reviewed-by: Philipp Deppenwiese --- src/vendorcode/google/chromeos/vboot2/antirollback.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'src/vendorcode/google/chromeos') diff --git a/src/vendorcode/google/chromeos/vboot2/antirollback.c b/src/vendorcode/google/chromeos/vboot2/antirollback.c index 621758ad47..bce2ca118a 100644 --- a/src/vendorcode/google/chromeos/vboot2/antirollback.c +++ b/src/vendorcode/google/chromeos/vboot2/antirollback.c @@ -128,7 +128,6 @@ static uint32_t safe_write(uint32_t index, const void *data, uint32_t length) static uint32_t set_firmware_space(const void *firmware_blob) { RETURN_ON_FAILURE(tlcl_define_space(FIRMWARE_NV_INDEX, - high_privilege, VB2_SECDATA_SIZE)); RETURN_ON_FAILURE(safe_write(FIRMWARE_NV_INDEX, firmware_blob, VB2_SECDATA_SIZE)); @@ -138,7 +137,6 @@ static uint32_t set_firmware_space(const void *firmware_blob) static uint32_t set_kernel_space(const void *kernel_blob) { RETURN_ON_FAILURE(tlcl_define_space(KERNEL_NV_INDEX, - low_privilege, sizeof(secdata_kernel))); RETURN_ON_FAILURE(safe_write(KERNEL_NV_INDEX, kernel_blob, sizeof(secdata_kernel))); -- cgit v1.2.3