vboot2: Add host lib function to create a vb2-style firmware preamble

And associated unit tests

BUG=chromium:423882
BRANCH=none
TEST=VBOOT2=1 make runtests

Change-Id: I3bf6ff6c6e32dfd0dd737f9b04ff0546e9e0a463
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/231728
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

2 files changed, 117 insertions, 0 deletions

diff --git a/host/lib/host_fw_preamble2.c b/host/lib/host_fw_preamble2.c
new file mode 100644
index 00000000..759af1b4
--- /dev/null
+++ b/host/lib/host_fw_preamble2.c
@@ -0,0 +1,81 @@
+/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Host functions for keyblocks
+ */
+
+#include "2sysincludes.h"
+#include "2common.h"
+#include "2rsa.h"
+#include "host_common.h"
+#include "host_fw_preamble2.h"
+#include "host_key2.h"
+#include "host_keyblock2.h"
+#include "host_misc.h"
+#include "host_signature2.h"
+
+int vb2_fw_preamble_create(struct vb2_fw_preamble2 **fp_ptr,
+			   const struct vb2_private_key *signing_key,
+			   const struct vb2_signature2 **hash_list,
+			   uint32_t hash_count,
+			   uint32_t fw_version,
+			   uint32_t flags,
+			   const char *desc)
+{
+	struct vb2_fw_preamble2 fp = {
+		.c.magic = VB2_MAGIC_FW_PREAMBLE2,
+		.c.struct_version_major = VB2_FW_PREAMBLE2_VERSION_MAJOR,
+		.c.struct_version_minor = VB2_FW_PREAMBLE2_VERSION_MAJOR,
+		.c.fixed_size = sizeof(fp),
+		.c.desc_size = vb2_desc_size(desc),
+		.flags = flags,
+		.firmware_version = fw_version,
+		.hash_count = hash_count,
+	};
+
+	uint32_t hash_next;
+	uint32_t sig_size;
+	uint8_t *buf;
+	int i;
+
+	*fp_ptr = NULL;
+
+	/* Determine component sizes */
+	hash_next = fp.hash_offset = fp.c.fixed_size + fp.c.desc_size;
+
+	for (i = 0; i < hash_count; i++)
+		hash_next += hash_list[i]->c.total_size;
+
+	fp.sig_offset = hash_next;
+
+	if (vb2_sig_size_for_key(&sig_size, signing_key, NULL))
+		return VB2_FW_PREAMBLE_CREATE_SIG_SIZE;
+
+	fp.c.total_size = fp.sig_offset + sig_size;
+
+	/* Allocate buffer and copy components */
+	buf = malloc(fp.c.total_size);
+	if (!buf)
+		return VB2_FW_PREAMBLE_CREATE_ALLOC;
+
+	memcpy(buf, &fp, sizeof(fp));
+	if (fp.c.desc_size)
+		strcpy((char *)buf + fp.c.fixed_size, desc);
+
+	hash_next = fp.hash_offset;
+	for (i = 0; i < hash_count; i++) {
+		memcpy(buf + hash_next, hash_list[i],
+		       hash_list[i]->c.total_size);
+		hash_next += hash_list[i]->c.total_size;
+	}
+
+	/* Sign the preamble */
+	if (vb2_sign_object(buf, fp.sig_offset, signing_key, NULL)) {
+		free(buf);
+		return VB2_FW_PREAMBLE_CREATE_SIGN;
+	}
+
+	*fp_ptr = (struct vb2_fw_preamble2 *)buf;
+	return VB2_SUCCESS;
+}
diff --git a/host/lib/include/host_fw_preamble2.h b/host/lib/include/host_fw_preamble2.h
new file mode 100644
index 00000000..d8c53838
--- /dev/null
+++ b/host/lib/include/host_fw_preamble2.h
@@ -0,0 +1,36 @@
+/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Host-side functions for firmware preamble
+ */
+
+#ifndef VBOOT_REFERENCE_HOST_FW_PREAMBLE2_H_
+#define VBOOT_REFERENCE_HOST_FW_PREAMBLE2_H_
+
+#include "2struct.h"
+
+struct vb2_private_key;
+
+/**
+ * Create and sign a firmware preamble.
+ *
+ * @param fp_ptr	On success, points to a newly allocated preamble buffer.
+ *			Caller is responsible for calling free() on this.
+ * @param signing_key	Key to sign the preamble with
+ * @param hash_list	Component hashes to include in the keyblock
+ * @param hash_count	Number of component hashes
+ * @param fw_version	Firmware version
+ * @param flags		Flags for preamble
+ * @param desc		Description for preamble, or NULL if none
+ * @return VB2_SUCCESS, or non-zero error code if failure.
+ */
+int vb2_fw_preamble_create(struct vb2_fw_preamble2 **fp_ptr,
+			   const struct vb2_private_key *signing_key,
+			   const struct vb2_signature2 **hash_list,
+			   uint32_t hash_count,
+			   uint32_t fw_version,
+			   uint32_t flags,
+			   const char *desc);
+
+#endif  /* VBOOT_REFERENCE_HOST_FW_PREAMBLE2_H_ */