[coreboot-gerrit] Change in coreboot[master]: src/security/vboot: Set up secure counter space in TPM NVRAM

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/59476 )

Change subject: src/security/vboot: Set up secure counter space in TPM NVRAM
......................................................................

src/security/vboot: Set up secure counter space in TPM NVRAM

High Definition (HD) protected content playback requires secure counters
that are updated at regular interval while the protected content is
playing. To support similar use-cases, define space for secure counters
in TPM NVRAM and initialize them. These counters are defined once during
the factory initialization stage. Also add
VBOOT_DEFINE_WIDEVINE_COUNTERS config item to enable these secure
counters only on the mainboard where they are required/used.

BUG=b:205261728
TEST=Build and boot to OS in guybrush. Ensure that the secure counters
are defined successfully in TPM NVRAM space.
tlcl_define_space: response is 0
tlcl_define_space: response is 0
tlcl_define_space: response is 0
tlcl_define_space: response is 0

On reboot if forced to redefine the space, it is identified as already
defined.
tlcl_define_space: response is 14c
define_space():219: define_space: Secure Counter space already exists
tlcl_define_space: response is 14c
define_space():219: define_space: Secure Counter space already exists
tlcl_define_space: response is 14c
define_space():219: define_space: Secure Counter space already exists
tlcl_define_space: response is 14c
define_space():219: define_space: Secure Counter space already exists

Change-Id: I915fbdada60e242d911b748ad5dc28028de9b657
Signed-off-by: Karthikeyan Ramasubramanian 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59476
Tested-by: build bot (Jenkins) 
Reviewed-by: Raul Rangel 
Reviewed-by: Julius Werner 
---
M src/security/vboot/Kconfig
M src/security/vboot/antirollback.h
M src/security/vboot/secdata_tpm.c
3 files changed, 43 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Julius Werner: Looks good to me, approved
  Raul Rangel: Looks good to me, approved

diff --git a/src/security/vboot/Kconfig b/src/security/vboot/Kconfig
index 7cbeea3..26f2484 100644
--- a/src/security/vboot/Kconfig
+++ b/src/security/vboot/Kconfig
@@ -282,6 +282,14 @@
      Use sha256msg1, sha256msg2, sha256rnds2 instruction to accelerate
      SHA hash calculation in vboot.

+config VBOOT_DEFINE_WIDEVINE_COUNTERS
+	bool
+	default n
+	help
+	  Set up Widevine Secure Counters in TPM NVRAM by defining space. Enabling this
+	  config will only define the counter space. Counters need to be incremented
+	  separately before any read operation is performed on them.
+
 menu "GBB configuration"

config GBB_HWID
diff --git a/src/security/vboot/antirollback.h b/src/security/vboot/antirollback.h
index 2297762..71605fa 100644
--- a/src/security/vboot/antirollback.h
+++ b/src/security/vboot/antirollback.h
@@ -29,6 +29,11 @@
 #define MRC_RW_HASH_NV_INDEX            0x100d
 #define HASH_NV_SIZE                    VB2_SHA256_DIGEST_SIZE
 #define ENT_ROLLBACK_COUNTER_INDEX      0x100e
+/* Widevine Secure Counter space */
+#define WIDEVINE_COUNTER_NV_INDEX(n)	(0x3000 + (n))
+#define NUM_WIDEVINE_COUNTERS		4
+#define WIDEVINE_COUNTER_NAME		"Widevine Secure Counter"
+#define WIDEVINE_COUNTER_SIZE		sizeof(uint64_t)
 /* Zero-Touch Enrollment related spaces */
 #define ZTE_BOARD_ID_NV_INDEX           0x3fff00
 #define ZTE_RMA_SN_BITS_INDEX           0x3fff01
diff --git a/src/security/vboot/secdata_tpm.c b/src/security/vboot/secdata_tpm.c
index 47efe2d..6d8e281 100644
--- a/src/security/vboot/secdata_tpm.c
+++ b/src/security/vboot/secdata_tpm.c
@@ -158,6 +158,18 @@
    .TPMA_NV_POLICY_DELETE = 1,
 };

+static const TPMA_NV rw_orderly_counter_attributes = {
+	.TPMA_NV_COUNTER = 1,
+	.TPMA_NV_ORDERLY = 1,
+	.TPMA_NV_AUTHREAD = 1,
+	.TPMA_NV_AUTHWRITE = 1,
+	.TPMA_NV_PLATFORMCREATE = 1,
+	.TPMA_NV_WRITE_STCLEAR = 1,
+	.TPMA_NV_PPREAD = 1,
+	.TPMA_NV_PPWRITE = 1,
+	.TPMA_NV_NO_DA = 1,
+};
+
 /*
  * This policy digest was obtained using TPM2_PolicyOR on 3 digests
  * corresponding to a sequence of
@@ -350,6 +362,19 @@
    			 rw_counter_attributes, NULL, 0);
 }

+static uint32_t setup_widevine_counter_spaces(void)
+{
+	uint32_t index, rv;
+
+	for (index = 0; index < NUM_WIDEVINE_COUNTERS; index++) {
+		rv = define_space(WIDEVINE_COUNTER_NAME, WIDEVINE_COUNTER_NV_INDEX(index),
+				WIDEVINE_COUNTER_SIZE, rw_orderly_counter_attributes, NULL, 0);
+		if (rv != TPM_SUCCESS)
+			return rv;
+	}
+	return TPM_SUCCESS;
+}
+
 static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
 {
    RETURN_ON_FAILURE(tlcl_force_clear());
@@ -391,6 +416,11 @@
    if (CONFIG(CHROMEOS))
    	RETURN_ON_FAILURE(enterprise_rollback_create_counter());

+	/* Define widevine counter space. No need to increment/write to the secure counters
+	   and are expected to be incremented during the first use. */
+	if (CONFIG(VBOOT_DEFINE_WIDEVINE_COUNTERS))
+		RETURN_ON_FAILURE(setup_widevine_counter_spaces());
+
    RETURN_ON_FAILURE(setup_firmware_space(ctx));

return TPM_SUCCESS;