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>

5 files changed, 255 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 310eeb0f..5de5e44a 100644
--- a/Makefile
+++ b/Makefile
@@ -376,6 +376,7 @@ UTILLIB_SRCS = \
 
 ifneq (${VBOOT2},)
 UTILLIB_SRCS += \
+	host/lib/host_fw_preamble2.c \
 	host/lib/host_key2.c \
 	host/lib/host_keyblock2.c \
 	host/lib/host_misc2.c \
@@ -639,6 +640,7 @@ TEST_NAMES += \
 	tests/vb2_common_tests \
 	tests/vb2_common2_tests \
 	tests/vb2_common3_tests \
+	tests/vb2_host_fw_preamble_tests \
 	tests/vb2_host_key_tests \
 	tests/vb2_host_keyblock_tests \
 	tests/vb2_host_misc_tests \
@@ -1000,6 +1002,7 @@ ${BUILD}/tests/vb2_api2_tests: LDLIBS += ${CRYPTO_LIBS}
 ${BUILD}/tests/vb2_common_tests: LDLIBS += ${CRYPTO_LIBS}
 ${BUILD}/tests/vb2_common2_tests: LDLIBS += ${CRYPTO_LIBS}
 ${BUILD}/tests/vb2_common3_tests: LDLIBS += ${CRYPTO_LIBS}
+${BUILD}/tests/vb2_host_fw_preamble_tests: LDLIBS += ${CRYPTO_LIBS}
 ${BUILD}/tests/vb2_host_key_tests: LDLIBS += ${CRYPTO_LIBS}
 ${BUILD}/tests/vb2_host_keyblock_tests: LDLIBS += ${CRYPTO_LIBS}
 ${BUILD}/tests/vb2_host_sig_tests: LDLIBS += ${CRYPTO_LIBS}
@@ -1182,6 +1185,7 @@ run2tests: test_setup
 	${RUNTEST} ${BUILD_RUN}/tests/vb2_common_tests
 	${RUNTEST} ${BUILD_RUN}/tests/vb2_common2_tests ${TEST_KEYS}
 	${RUNTEST} ${BUILD_RUN}/tests/vb2_common3_tests ${TEST_KEYS}
+	${RUNTEST} ${BUILD_RUN}/tests/vb2_host_fw_preamble_tests ${TEST_KEYS}
 	${RUNTEST} ${BUILD_RUN}/tests/vb2_host_key_tests ${TEST_KEYS}
 	${RUNTEST} ${BUILD_RUN}/tests/vb2_host_keyblock_tests ${TEST_KEYS}
 	${RUNTEST} ${BUILD_RUN}/tests/vb2_host_misc_tests
diff --git a/firmware/2lib/include/2return_codes.h b/firmware/2lib/include/2return_codes.h
index 7a59925a..3d1c611a 100644
--- a/firmware/2lib/include/2return_codes.h
+++ b/firmware/2lib/include/2return_codes.h
@@ -617,6 +617,20 @@ enum vb2_return_code {
 	VB2_KEYBLOCK_CREATE_SIGN,
 
         /**********************************************************************
+	 * Errors generated by host library firmware preamble functions
+	 */
+	VB2_ERROR_HOST_FW_PREAMBLE = VB2_ERROR_HOST_BASE + 0x050000,
+
+	/* Unable to determine signature sizes for vb2_create_fw_preamble() */
+	VB2_FW_PREAMBLE_CREATE_SIG_SIZE,
+
+	/* Unable to allocate buffer in vb2_create_fw_preamble() */
+	VB2_FW_PREAMBLE_CREATE_ALLOC,
+
+	/* Unable to sign preamble in vb2_create_fw_preamble() */
+	VB2_FW_PREAMBLE_CREATE_SIGN,
+
+        /**********************************************************************
 	 * Highest non-zero error generated inside vboot library.  Note that
 	 * error codes passed through vboot when it calls external APIs may
 	 * still be outside this range.
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_ */
diff --git a/tests/vb2_host_fw_preamble_tests.c b/tests/vb2_host_fw_preamble_tests.c
new file mode 100644
index 00000000..0063ba82
--- /dev/null
+++ b/tests/vb2_host_fw_preamble_tests.c
@@ -0,0 +1,120 @@
+/* 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.
+ *
+ * Tests for host library vboot2 preamble functions
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+
+#include "2sysincludes.h"
+#include "2common.h"
+#include "2rsa.h"
+#include "host_common.h"
+#include "host_fw_preamble2.h"
+#include "host_key2.h"
+#include "host_signature2.h"
+
+#include "test_common.h"
+
+const uint8_t test_data1[] = "Some test data";
+const uint8_t test_data2[] = "Some more test data";
+const uint8_t test_data3[] = "Even more test data";
+
+static void preamble_tests(const char *keys_dir)
+{
+	struct vb2_private_key *prik4096;
+	struct vb2_public_key *pubk4096;
+	struct vb2_fw_preamble2 *fp;
+	const struct vb2_private_key *prikhash;
+	struct vb2_signature2 *hashes[3];
+	char fname[1024];
+	const char test_desc[] = "Test fw preamble";
+	const uint32_t test_version = 2061;
+	const uint32_t test_flags = 0x11223344;
+	uint32_t hash_next;
+	int i;
+
+	uint8_t workbuf[VB2_VERIFY_FIRMWARE_PREAMBLE_WORKBUF_BYTES];
+	struct vb2_workbuf wb;
+
+	vb2_workbuf_init(&wb, workbuf, sizeof(workbuf));
+
+	/* Read keys */
+	sprintf(fname, "%s/key_rsa4096.keyb", keys_dir);
+	TEST_SUCC(vb2_public_key_read_keyb(&pubk4096, fname),
+					   "Read public key 1");
+	vb2_public_key_set_desc(pubk4096, "Test RSA4096 public key");
+	pubk4096->hash_alg = VB2_HASH_SHA256;
+
+	sprintf(fname, "%s/key_rsa4096.pem", keys_dir);
+	TEST_SUCC(vb2_private_key_read_pem(&prik4096, fname),
+		  "Read private key 2");
+	vb2_private_key_set_desc(prik4096, "Test RSA4096 private key");
+	prik4096->sig_alg = VB2_SIG_RSA4096;
+	prik4096->hash_alg = VB2_HASH_SHA256;
+
+	TEST_SUCC(vb2_private_key_hash(&prikhash, VB2_HASH_SHA256),
+			  "Create private hash key");
+
+	/* Create some signatures */
+	TEST_SUCC(vb2_sign_data(hashes + 0, test_data1, sizeof(test_data1),
+				prikhash, "Hash 1"),
+		  "Hash 1");
+	TEST_SUCC(vb2_sign_data(hashes + 1, test_data2, sizeof(test_data2),
+				prikhash, "Hash 2"),
+		  "Hash 2");
+	TEST_SUCC(vb2_sign_data(hashes + 2, test_data3, sizeof(test_data3),
+				prikhash, "Hash 3"),
+			  "Hash 3");
+
+	/* Test good preamble */
+	TEST_SUCC(vb2_fw_preamble_create(&fp, prik4096,
+					 (const struct vb2_signature2 **)hashes,
+					 3, test_version, test_flags,
+					 test_desc),
+		  "Create preamble good");
+	TEST_PTR_NEQ(fp, NULL, "  fp_ptr");
+	TEST_SUCC(vb2_verify_fw_preamble2(fp, fp->c.total_size, pubk4096, &wb),
+		  "Verify preamble good");
+	TEST_EQ(strcmp(vb2_common_desc(fp), test_desc), 0, "  desc");
+	TEST_EQ(fp->firmware_version, test_version, "  firmware_version");
+	TEST_EQ(fp->flags, test_flags, "  flags");
+	TEST_EQ(fp->hash_count, 3, "  hash_count");
+
+	hash_next = fp->hash_offset;
+	for (i = 0; i < 3; i++) {
+		TEST_EQ(0, memcmp((uint8_t *)fp + hash_next, hashes[i],
+				  hashes[i]->c.total_size), "  hash[i]");
+		hash_next += hashes[i]->c.total_size;
+	}
+
+	free(fp);
+
+	/* Test errors */
+	prik4096->hash_alg = VB2_HASH_INVALID;
+	TEST_EQ(vb2_fw_preamble_create(&fp, prik4096,
+				       (const struct vb2_signature2 **)hashes,
+				       3, test_version, test_flags,
+				       test_desc),
+		VB2_FW_PREAMBLE_CREATE_SIG_SIZE,
+		"Create preamble bad sig");
+	TEST_PTR_EQ(fp, NULL, "  fp_ptr");
+
+	/* Free keys */
+	vb2_public_key_free(pubk4096);
+	vb2_private_key_free(prik4096);
+}
+
+int main(int argc, char *argv[]) {
+
+	if (argc == 2) {
+		preamble_tests(argv[1]);
+	} else {
+		fprintf(stderr, "Usage: %s <keys_dir>", argv[0]);
+		return -1;
+	}
+
+	return gTestSuccess ? 0 : 255;
+}