security/vboot: Add new TPM NVRAM index MRC_RW_HASH_NV_INDEX

Add new index for MRC_CACHE data in RW.  Also update antirollback
functions to handle this new index where necessary.

BUG=b:150502246
BRANCH=None
TEST=make sure memory training still works on nami

Change-Id: I2de3c23aa56d3b576ca54dbd85c75e5b80199560
Signed-off-by: Shelley Chen <shchen@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46511
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/security/vboot/antirollback.h

@@ -24,6 +24,9 @@ enum vb2_pcr_digest;
 #define FWMP_NV_INDEX                   0x100a
 /* 0x100b: Hash of MRC_CACHE training data for recovery boot */
 #define MRC_REC_HASH_NV_INDEX           0x100b
+/* 0x100c: OOBE autoconfig public key hashes */
+/* 0x100d: Hash of MRC_CACHE training data for non-recovery boot */
+#define MRC_RW_HASH_NV_INDEX            0x100d
 #define HASH_NV_SIZE                    VB2_SHA256_DIGEST_SIZE
 
 /* Structure definitions for TPM spaces */
@@ -57,23 +60,32 @@ uint32_t antirollback_write_space_kernel(struct vb2_context *ctx);
 uint32_t antirollback_lock_space_firmware(void);
 
 /*
- * Read recovery hash data from TPM.
+ * Read MRC hash data from TPM.
- * @param index index into TPM NVRAM where hash is stored
+ * @param index index into TPM NVRAM where hash is stored The index
+ *              can be set to either MRC_REC_HASH_NV_INDEX or
+ *              MRC_RW_HASH_NV_INDEX depending upon whether we are
+ *              booting in recovery or normal mode.
  * @param data  pointer to buffer where hash from TPM read into
  * @param size  size of buffer
  */
 uint32_t antirollback_read_space_mrc_hash(uint32_t index, uint8_t *data, uint32_t size);
 /*
- * Write new hash data to recovery space in TPM.\
+ * Write new hash data to MRC space in TPM.\
- * @param index index into TPM NVRAM where hash is stored
+ * @param index index into TPM NVRAM where hash is stored The index
+ *              can be set to either MRC_REC_HASH_NV_INDEX or
+ *              MRC_RW_HASH_NV_INDEX depending upon whether we are
+ *              booting in recovery or normal mode.
  * @param data  pointer to buffer of hash value to be written
  * @param size  size of buffer
 */
 uint32_t antirollback_write_space_mrc_hash(uint32_t index, const uint8_t *data,
 					   uint32_t size);
 /*
- * Lock down recovery hash space in TPM.
+ * Lock down MRC hash space in TPM.
- * @param index index into TPM NVRAM where hash is stored
+ * @param index index into TPM NVRAM where hash is stored The index
+ *              can be set to either MRC_REC_HASH_NV_INDEX or
+ *              MRC_RW_HASH_NV_INDEX depending upon whether we are
+ *              booting in recovery or normal mode.
 */
 uint32_t antirollback_lock_space_mrc_hash(uint32_t index);
 

src/security/vboot/secdata_tpm.c

@@ -164,9 +164,14 @@ static uint32_t set_kernel_space(const void *kernel_blob)
 
 static uint32_t set_mrc_hash_space(uint32_t index, const uint8_t *data)
 {
-	return set_space("MRC Hash", index, data, HASH_NV_SIZE,
+	if (index == MRC_REC_HASH_NV_INDEX) {
+		return set_space("RO MRC Hash", index, data, HASH_NV_SIZE,
 				 ro_space_attributes, pcr0_unchanged_policy,
 				 sizeof(pcr0_unchanged_policy));
+	} else {
+		return set_space("RW MRC Hash", index, data, HASH_NV_SIZE,
+				 rw_space_attributes, NULL, 0);
+	}
 }
 
 static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
@@ -183,6 +188,13 @@ static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
 	 */
 	RETURN_ON_FAILURE(set_kernel_space(ctx->secdata_kernel));
 
+	/*
+	 * Define and set rec hash space, if available.  No need to
+	 * create the RW hash space because we will definitely boot
+	 * once in normal mode before shipping, meaning that the space
+	 * will get created with correct permissions while still in in
+	 * our hands.
+	 */
 	if (CONFIG(VBOOT_HAS_REC_HASH_SPACE))
 		RETURN_ON_FAILURE(set_mrc_hash_space(MRC_REC_HASH_NV_INDEX, mrc_hash_data));
 
@@ -304,7 +316,13 @@ static uint32_t _factory_initialize_tpm(struct vb2_context *ctx)
 				     ctx->secdata_firmware,
 					VB2_SECDATA_FIRMWARE_SIZE));
 
-	/* Define and set rec hash space, if available. */
+	/*
+	 * Define and set rec hash space, if available.  No need to
+	 * create the RW hash space because we will definitely boot
+	 * once in normal mode before shipping, meaning that the space
+	 * will get created with correct permissions while still in in
+	 * our hands.
+	 */
 	if (CONFIG(VBOOT_HAS_REC_HASH_SPACE))
 		RETURN_ON_FAILURE(set_mrc_hash_space(MRC_REC_HASH_NV_INDEX, mrc_hash_data));