cbfs/vboot: Adapt to new vb2_digest API

CL:3825558 changes all vb2_digest and vb2_hash functions to take a new
hwcrypto_allowed argument, to potentially let them try to call the
vb2ex_hwcrypto API for hash calculation. This change will open hardware
crypto acceleration up to all hash calculations in coreboot (most
notably CBFS verification). As part of this change, the
vb2_digest_buffer() function has been removed, so replace existing
instances in coreboot with the newer vb2_hash_calculate() API.

Due to the circular dependency of these changes with vboot, this patch
also needs to update the vboot submodule:

Updating from commit id 18cb85b5:
    2load_kernel.c: Expose load kernel as vb2_api

to commit id b827ddb9:
    tests: Ensure auxfw sync runs after EC sync

This brings in 15 new commits.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I287d8dac3c49ad7ea3e18a015874ce8d610ec67e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66561
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jakub Czapiga <jacz@semihalf.com>

3 files changed, 27 insertions, 30 deletions

diff --git a/src/security/vboot/misc.h b/src/security/vboot/misc.h
index c39af08f1b..8310647760 100644
--- a/src/security/vboot/misc.h
+++ b/src/security/vboot/misc.h
@@ -87,4 +87,18 @@ static inline int vboot_logic_executed(void)
 	}
 }
 
+static inline bool vboot_hwcrypto_allowed(void)
+{
+	/* When not using vboot firmware verification, HW crypto is always allowed. */
+	if (!CONFIG(VBOOT))
+		return 1;
+
+	/* Before vboot runs we can't check for HW crypto, so err on the side of caution. */
+	if (!vboot_logic_executed())
+		return 0;
+
+	/* Otherwise, vboot can decide. */
+	return vb2api_hwcrypto_allowed(vboot_get_context());
+}
+
 #endif /* __VBOOT_MISC_H__ */
diff --git a/src/security/vboot/mrc_cache_hash_tpm.c b/src/security/vboot/mrc_cache_hash_tpm.c
index 77c23f63e4..f67eae48cb 100644
--- a/src/security/vboot/mrc_cache_hash_tpm.c
+++ b/src/security/vboot/mrc_cache_hash_tpm.c
@@ -2,27 +2,16 @@
 
 #include <security/vboot/antirollback.h>
 #include <program_loading.h>
-#include <security/vboot/vboot_common.h>
 #include <vb2_api.h>
 #include <security/tpm/tss.h>
+#include <security/vboot/misc.h>
 #include <security/vboot/mrc_cache_hash_tpm.h>
 #include <console/console.h>
 #include <string.h>
 
 void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size)
 {
-	uint8_t data_hash[VB2_SHA256_DIGEST_SIZE];
-	static const uint8_t dead_hash[VB2_SHA256_DIGEST_SIZE] = {
-		0xba, 0xad, 0xda, 0x1a, /* BAADDA1A */
-		0xde, 0xad, 0xde, 0xad, /* DEADDEAD */
-		0xde, 0xad, 0xda, 0x1a, /* DEADDA1A */
-		0xba, 0xad, 0xba, 0xad, /* BAADBAAD */
-		0xba, 0xad, 0xda, 0x1a, /* BAADDA1A */
-		0xde, 0xad, 0xde, 0xad, /* DEADDEAD */
-		0xde, 0xad, 0xda, 0x1a, /* DEADDA1A */
-		0xba, 0xad, 0xba, 0xad, /* BAADBAAD */
-	};
-	const uint8_t *hash_ptr = data_hash;
+	struct vb2_hash hash;
 
 	/* Initialize TPM driver. */
 	if (tlcl_lib_init() != VB2_SUCCESS) {
@@ -31,8 +20,8 @@ void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size)
 	}
 
 	/* Calculate hash of data generated by MRC. */
-	if (vb2_digest_buffer(data, size, VB2_HASH_SHA256, data_hash,
-			      sizeof(data_hash))) {
+	if (vb2_hash_calculate(vboot_hwcrypto_allowed(), data, size,
+			       VB2_HASH_SHA256, &hash)) {
 		printk(BIOS_ERR, "MRC: SHA-256 calculation failed for data. "
 		       "Not updating TPM hash space.\n");
 		/*
@@ -40,13 +29,13 @@ void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size)
 		 * currently stored in TPM hash space is no longer
 		 * valid. If we are not able to calculate hash of the
 		 * data being updated, reset all the bits in TPM hash
-		 * space to pre-defined hash pattern.
+		 * space to zero to invalidate it.
 		 */
-		hash_ptr = dead_hash;
+		memset(hash.raw, 0, VB2_SHA256_DIGEST_SIZE);
 	}
 
 	/* Write hash of data to TPM space. */
-	if (antirollback_write_space_mrc_hash(index, hash_ptr, VB2_SHA256_DIGEST_SIZE)
+	if (antirollback_write_space_mrc_hash(index, hash.sha256, sizeof(hash.sha256))
 	    != TPM_SUCCESS) {
 		printk(BIOS_ERR, "MRC: Could not save hash to TPM.\n");
 		return;
@@ -57,15 +46,7 @@ void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size)
 
 int mrc_cache_verify_hash(uint32_t index, const uint8_t *data, size_t size)
 {
-	uint8_t data_hash[VB2_SHA256_DIGEST_SIZE];
-	uint8_t tpm_hash[VB2_SHA256_DIGEST_SIZE];
-
-	/* Calculate hash of data read from MRC_CACHE. */
-	if (vb2_digest_buffer(data, size, VB2_HASH_SHA256, data_hash,
-			      sizeof(data_hash))) {
-		printk(BIOS_ERR, "MRC: SHA-256 calculation failed for data.\n");
-		return 0;
-	}
+	struct vb2_hash tpm_hash = { .algo = VB2_HASH_SHA256 };
 
 	/* Initialize TPM driver. */
 	if (tlcl_lib_init() != VB2_SUCCESS) {
@@ -74,13 +55,14 @@ int mrc_cache_verify_hash(uint32_t index, const uint8_t *data, size_t size)
 	}
 
 	/* Read hash of MRC data saved in TPM. */
-	if (antirollback_read_space_mrc_hash(index, tpm_hash, sizeof(tpm_hash))
+	if (antirollback_read_space_mrc_hash(index, tpm_hash.sha256, sizeof(tpm_hash.sha256))
 	    != TPM_SUCCESS) {
 		printk(BIOS_ERR, "MRC: Could not read hash from TPM.\n");
 		return 0;
 	}
 
-	if (memcmp(tpm_hash, data_hash, sizeof(tpm_hash))) {
+	/* Calculate hash of data read from MRC_CACHE and compare. */
+	if (vb2_hash_verify(vboot_hwcrypto_allowed(), data, size, &tpm_hash)) {
 		printk(BIOS_ERR, "MRC: Hash comparison failed.\n");
 		return 0;
 	}
diff --git a/src/security/vboot/tpm_common.c b/src/security/vboot/tpm_common.c
index 7fb2a9d3c5..e67cc01322 100644
--- a/src/security/vboot/tpm_common.c
+++ b/src/security/vboot/tpm_common.c
@@ -1,8 +1,9 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <security/tpm/tspi.h>
-#include <vb2_api.h>
 #include <security/vboot/tpm_common.h>
+#include <vb2_api.h>
+#include <vb2_sha.h>
 
 #define TPM_PCR_BOOT_MODE "VBOOT: boot mode"
 #define TPM_PCR_GBB_HWID_NAME "VBOOT: GBB HWID"