firmware: host: futility: Add CBFS metadata hash supportstabilize-15183.14.B

This patch adds support for signing and verification of coreboot images
supporting VBOOT_CBFS_INTEGRATION. Images with config option
CONFIG_VBOOT_CBFS_INTEGRATION=y will be signed with CBFS metadata hash
in signature. vb2api_get_metadata_hash() should be used to extract hash
value from VBLOCK and then should be used to verify CBFS metadata.
To support full verification, CBFS file data verification should also be
enabled and correctly handled.

BUG=b:197114807
TEST=build with CB:66909 and boot on volteer/voxel with
     CONFIG_VBOOT_CBFS_INTEGRATION=y
BRANCH=none

Signed-off-by: Jakub Czapiga <czapiga@google.com>
Change-Id: I4075c84820949be24c423ed14e291c89a0032863
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3811754
Commit-Queue: Julius Werner <jwerner@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>

1 files changed, 88 insertions, 8 deletions

diff --git a/tests/vb2_api_tests.c b/tests/vb2_api_tests.c
index 23078cf9..3ed8bd5f 100644
--- a/tests/vb2_api_tests.c
+++ b/tests/vb2_api_tests.c
@@ -38,6 +38,16 @@ const int mock_sig_size = 64;
 static uint8_t digest_result[VB2_SHA256_DIGEST_SIZE];
 static const uint32_t digest_result_size = sizeof(digest_result);
 
+static const struct vb2_hash mock_mhash = {
+	.algo = VB2_HASH_SHA256,
+	.sha256 = {
+		0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+		0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+		0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+		0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+	},
+};
+
 /* Mocked function data */
 
 static int force_dev_mode;
@@ -56,6 +66,7 @@ enum reset_type {
 	FOR_MISC,
 	FOR_EXTEND_HASH,
 	FOR_CHECK_HASH,
+	FOR_METADATA_HASH,
 };
 
 static void reset_common_data(enum reset_type t)
@@ -93,15 +104,31 @@ static void reset_common_data(enum reset_type t)
 	sd->preamble_size = sizeof(*pre);
 	vb2_set_workbuf_used(ctx, sd->preamble_offset + sd->preamble_size);
 	pre = vb2_member_of(sd, sd->preamble_offset);
-	pre->body_signature.data_size = mock_body_size;
-	pre->body_signature.sig_size = mock_sig_size;
-	pre->flags = 0;
 
-	sd->data_key_offset = sd->workbuf_used;
-	sd->data_key_size = sizeof(*k) + 8;
-	vb2_set_workbuf_used(ctx, sd->data_key_offset + sd->data_key_size);
-	k = vb2_member_of(sd, sd->data_key_offset);
-	k->algorithm = mock_algorithm;
+	if (t == FOR_METADATA_HASH) {
+		struct vb2_hash *mhash;
+		pre->body_signature.data_size = 0;
+		pre->body_signature.sig_size = offsetof(struct vb2_hash, raw) +
+					       vb2_digest_size(mock_mhash.algo);
+		pre->body_signature.sig_offset =
+			vb2_offset_of(&pre->body_signature,
+				      vb2_member_of(sd, sd->workbuf_used));
+		pre->flags = 0;
+		mhash = vb2_member_of(sd, sd->workbuf_used);
+		vb2_set_workbuf_used(ctx, pre->body_signature.sig_size);
+		memcpy(mhash, &mock_mhash, pre->body_signature.sig_size);
+	} else {
+		pre->body_signature.data_size = mock_body_size;
+		pre->body_signature.sig_size = mock_sig_size;
+		pre->flags = 0;
+
+		sd->data_key_offset = sd->workbuf_used;
+		sd->data_key_size = sizeof(*k) + 8;
+		vb2_set_workbuf_used(ctx,
+				     sd->data_key_offset + sd->data_key_size);
+		k = vb2_member_of(sd, sd->data_key_offset);
+		k->algorithm = mock_algorithm;
+	}
 
 	if (t == FOR_EXTEND_HASH || t == FOR_CHECK_HASH)
 		vb2api_init_hash(ctx, VB2_HASH_TAG_FW_BODY);
@@ -604,6 +631,7 @@ static void init_hash_tests(void)
 {
 	struct vb2_packed_key *k;
 	int wb_used_before;
+	struct vb2_fw_preamble *pre;
 
 	/* For now, all we support is body signature hash */
 	reset_common_data(FOR_MISC);
@@ -649,6 +677,12 @@ static void init_hash_tests(void)
 		VB2_ERROR_API_INIT_HASH_DATA_KEY, "init hash data key");
 
 	reset_common_data(FOR_MISC);
+	pre = vb2_member_of(sd, sd->preamble_offset);
+	pre->body_signature.data_size = 0;
+	TEST_EQ(vb2api_init_hash(ctx, VB2_HASH_TAG_FW_BODY),
+		VB2_ERROR_API_INIT_HASH_DATA_KEY, "init hash data size");
+
+	reset_common_data(FOR_MISC);
 	sd->data_key_size--;
 	TEST_EQ(vb2api_init_hash(ctx, VB2_HASH_TAG_FW_BODY),
 		VB2_ERROR_UNPACK_KEY_SIZE, "init hash data key size");
@@ -792,6 +826,50 @@ static void check_hash_tests(void)
 		VB2_ERROR_RSA_VERIFY_DIGEST, "check hash finalize");
 }
 
+static void get_metadata_hash_test(void)
+{
+	struct vb2_hash *hash;
+	struct vb2_fw_preamble *pre;
+
+	reset_common_data(FOR_MISC);
+	TEST_EQ(vb2api_get_metadata_hash(ctx, &hash),
+		VB2_ERROR_API_INIT_HASH_DATA_KEY, "check body sig data size");
+
+	reset_common_data(FOR_MISC);
+	sd->preamble_size = 0;
+	TEST_EQ(vb2api_get_metadata_hash(ctx, &hash),
+		VB2_ERROR_API_CHECK_HASH_PREAMBLE, "check preamble size");
+
+	reset_common_data(FOR_METADATA_HASH);
+	pre = vb2_member_of(sd, sd->preamble_offset);
+	pre->body_signature.sig_size = 8;
+	TEST_EQ(vb2api_get_metadata_hash(ctx, &hash),
+		VB2_ERROR_API_CHECK_HASH_SIG_SIZE, "check too small sig size");
+
+	reset_common_data(FOR_METADATA_HASH);
+	pre = vb2_member_of(sd, sd->preamble_offset);
+	pre->body_signature.data_size = mock_body_size;
+	TEST_EQ(vb2api_get_metadata_hash(ctx, &hash),
+		VB2_ERROR_API_INIT_HASH_DATA_KEY, "check incorrect data size");
+
+	reset_common_data(FOR_METADATA_HASH);
+	pre = vb2_member_of(sd, sd->preamble_offset);
+	hash = (struct vb2_hash *)vb2_signature_data_mutable(
+		&pre->body_signature);
+	hash->algo = VB2_HASH_INVALID;
+	TEST_EQ(vb2api_get_metadata_hash(ctx, &hash),
+		VB2_ERROR_API_CHECK_HASH_SIG_SIZE, "check unsupported algo");
+
+	reset_common_data(FOR_METADATA_HASH);
+	TEST_EQ(vb2api_get_metadata_hash(ctx, &hash), VB2_SUCCESS,
+		"check metadata hash get");
+	TEST_PTR_NEQ(hash, NULL, "check metadata hash not null");
+	TEST_EQ(hash->algo, mock_mhash.algo, "check metadata hash algo");
+	TEST_EQ(memcmp(hash->raw, mock_mhash.raw,
+		       vb2_digest_size(mock_mhash.algo)),
+		0, "check metadata hash digest");
+}
+
 int main(int argc, char* argv[])
 {
 	misc_tests();
@@ -803,6 +881,8 @@ int main(int argc, char* argv[])
 	extend_hash_tests();
 	check_hash_tests();
 
+	get_metadata_hash_test();
+
 	get_pcr_digest_tests();
 
 	return gTestSuccess ? 0 : 255;