[coreboot-gerrit] New patch to review for coreboot: 22982d4 vboot2: factory-initialize kernel space in tpm

[Aaron Durbin (adurbin@google.com)]

Aaron Durbin (adurbin at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/8885

-gerrit

commit 22982d446d93451115e9f82495cc6e0e9958a45f
Author: Daisuke Nojiri <dnojiri at chromium.org>
Date:   Mon Sep 29 13:02:29 2014 -0700

    vboot2: factory-initialize kernel space in tpm
    
    this change makes coreboot initialize kernel space and backup space in the tpm
    when no firmware space is found in the tpm.
    
    BUG=chrome-os-partner:32410
    TEST=Forced factory initialization and verified it went through without errors.
    BRANCH=None
    Signed-off-by: Daisuke Nojiri <dnojiri at chromium.org>
    
    Original-Change-Id: I777e3cb7004870c769163827543c83665d3732b9
    Original-Reviewed-on: https://chromium-review.googlesource.com/220412
    Original-Reviewed-by: Julius Werner <jwerner at chromium.org>
    Original-Reviewed-by: Randall Spangler <rspangler at chromium.org>
    Original-Commit-Queue: Daisuke Nojiri <dnojiri at chromium.org>
    Original-Tested-by: Daisuke Nojiri <dnojiri at chromium.org>
    (cherry picked from commit d8c0c407bf0fed60d76441ada7bedd36f6fc3a38)
    
    Change-Id: Icc3779125262b4499e47781991ebbf584abf074a
    Signed-off-by: Aaron Durbin <adurbin at chromium.org>
---
 src/include/antirollback.h                    |  3 ++
 src/vendorcode/google/chromeos/antirollback.c | 61 ++++++++++++++++++++-------
 2 files changed, 49 insertions(+), 15 deletions(-)

diff --git a/src/include/antirollback.h b/src/include/antirollback.h
index 0473e24..06ad9f7 100644
--- a/src/include/antirollback.h
+++ b/src/include/antirollback.h
@@ -15,6 +15,9 @@
 
 /* TPM NVRAM location indices. */
 #define FIRMWARE_NV_INDEX               0x1007
+#define KERNEL_NV_INDEX                 0x1008
+/* This is just an opaque space for backup purposes */
+#define BACKUP_NV_INDEX                 0x1009
 
 /* Structure definitions for TPM spaces */
 
diff --git a/src/vendorcode/google/chromeos/antirollback.c b/src/vendorcode/google/chromeos/antirollback.c
index 020a06a..bb547b5 100644
--- a/src/vendorcode/google/chromeos/antirollback.c
+++ b/src/vendorcode/google/chromeos/antirollback.c
@@ -34,7 +34,6 @@
 		}							\
 	} while (0)
 
-
 uint32_t tpm_clear_and_reenable(void)
 {
 	VBDEBUG("TPM: Clear and re-enable\n");
@@ -85,30 +84,36 @@ static uint32_t read_space_firmware(struct vb2_context *ctx)
 	return TPM_E_CORRUPTED_STATE;
 }
 
-static uint32_t write_space_firmware(struct vb2_context *ctx)
+static uint32_t write_secdata(uint32_t index,
+			      const uint8_t *secdata,
+			      uint32_t len)
 {
-	uint8_t secdata[VB2_SECDATA_SIZE];
-	uint32_t r;
+	uint8_t sd[32];
+	uint32_t rv;
 	int attempts = 3;
 
-	memcpy(secdata, ctx->secdata, VB2_SECDATA_SIZE);
+	if (len > sizeof(sd)) {
+		VBDEBUG("TPM: %s() - data is too large\n", __func__);
+		return TPM_E_WRITE_FAILURE;
+	}
+
 	while (attempts--) {
-		r = safe_write(FIRMWARE_NV_INDEX, secdata, VB2_SECDATA_SIZE);
+		rv = safe_write(index, secdata, len);
 		/* Can't write, not gonna try again */
-		if (r != TPM_SUCCESS)
-			return r;
+		if (rv != TPM_SUCCESS)
+			return rv;
 
 		/* Read it back to be sure it got the right values. */
-		r = read_space_firmware(ctx);
-		if (r == TPM_SUCCESS && memcmp(secdata, ctx->secdata,
-		                               VB2_SECDATA_SIZE) == 0)
-			return r;
+		rv = tlcl_read(index, sd, len);
+		if (rv == TPM_SUCCESS && memcmp(secdata, sd, len) == 0)
+			return rv;
 
-		VBDEBUG("TPM: %s() failed\n", __func__);
+		VBDEBUG("TPM: %s() failed. trying again\n", __func__);
 		/* Try writing it again. Maybe it was garbled on the way out. */
 	}
 
 	VBDEBUG("TPM: %s() - too many failures, giving up\n", __func__);
+
 	return TPM_E_CORRUPTED_STATE;
 }
 
@@ -116,6 +121,15 @@ uint32_t factory_initialize_tpm(struct vb2_context *ctx)
 {
 	TPM_PERMANENT_FLAGS pflags;
 	uint32_t result;
+	/* this is derived from rollback_index.h of vboot_reference. see struct
+	 * RollbackSpaceKernel for details. */
+	static const uint8_t secdata_kernel[] = {
+			0x02,
+			0x4C, 0x57, 0x52, 0x47,
+			0x00, 0x00, 0x00, 0x00,
+			0x00, 0x00, 0x00,
+			0xE8,
+	};
 
 	VBDEBUG("TPM: factory initialization\n");
 
@@ -161,13 +175,30 @@ uint32_t factory_initialize_tpm(struct vb2_context *ctx)
 	VBDEBUG("TPM: Clearing owner\n");
 	RETURN_ON_FAILURE(tpm_clear_and_reenable());
 
+	/* Define the backup space. No need to initialize it, though. */
+	RETURN_ON_FAILURE(safe_define_space(BACKUP_NV_INDEX,
+					    TPM_NV_PER_PPWRITE,
+					    VB2_NVDATA_SIZE));
+
+	/* Define and initialize the kernel space */
+	RETURN_ON_FAILURE(safe_define_space(KERNEL_NV_INDEX,
+					    TPM_NV_PER_PPWRITE,
+					    sizeof(secdata_kernel)));
+	RETURN_ON_FAILURE(write_secdata(KERNEL_NV_INDEX,
+					secdata_kernel,
+					sizeof(secdata_kernel)));
+
 	/* Defines and sets vb2 secdata space */
 	vb2api_secdata_create(ctx);
 	RETURN_ON_FAILURE(safe_define_space(FIRMWARE_NV_INDEX,
 	                                    TPM_NV_PER_GLOBALLOCK |
 	                                    TPM_NV_PER_PPWRITE,
 	                                    VB2_SECDATA_SIZE));
-	RETURN_ON_FAILURE(write_space_firmware(ctx));
+	RETURN_ON_FAILURE(write_secdata(FIRMWARE_NV_INDEX,
+					ctx->secdata,
+					VB2_SECDATA_SIZE));
+
+	VBDEBUG("TPM: factory initialization successful\n");
 
 	return TPM_SUCCESS;
 }
@@ -289,7 +320,7 @@ uint32_t antirollback_read_space_firmware(struct vb2_context *ctx)
 
 uint32_t antirollback_write_space_firmware(struct vb2_context *ctx)
 {
-	return write_space_firmware(ctx);
+	return write_secdata(FIRMWARE_NV_INDEX, ctx->secdata, VB2_SECDATA_SIZE);
 }
 
 uint32_t antirollback_lock_space_firmware()