mirror of
https://github.com/Telecominfraproject/OpenCellular.git
synced 2025-11-24 18:25:10 +00:00
Remove unused files, and tidy the directory structure of the remaining ones.
Review URL: http://codereview.chromium.org/2815011
This commit is contained in:
Randall Spangler
379
firmware/lib/vboot_kernel.c
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379
firmware/lib/vboot_kernel.c
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@@ -0,0 +1,379 @@
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/* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*
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* Functions for loading a kernel from disk.
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* (Firmware portion)
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*/
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#include "vboot_kernel.h"
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#include "boot_device.h"
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#include "cgptlib.h"
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#include "load_kernel_fw.h"
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#include "rollback_index.h"
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#include "utility.h"
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#include "vboot_common.h"
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#define KBUF_SIZE 65536 /* Bytes to read at start of kernel partition */
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/* Allocates and reads GPT data from the drive. The sector_bytes and
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* drive_sectors fields should be filled on input. The primary and
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* secondary header and entries are filled on output.
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*
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* Returns 0 if successful, 1 if error. */
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int AllocAndReadGptData(GptData* gptdata) {
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uint64_t entries_sectors = TOTAL_ENTRIES_SIZE / gptdata->sector_bytes;
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/* No data to be written yet */
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gptdata->modified = 0;
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/* Allocate all buffers */
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gptdata->primary_header = (uint8_t*)Malloc(gptdata->sector_bytes);
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gptdata->secondary_header = (uint8_t*)Malloc(gptdata->sector_bytes);
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gptdata->primary_entries = (uint8_t*)Malloc(TOTAL_ENTRIES_SIZE);
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gptdata->secondary_entries = (uint8_t*)Malloc(TOTAL_ENTRIES_SIZE);
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if (gptdata->primary_header == NULL || gptdata->secondary_header == NULL ||
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gptdata->primary_entries == NULL || gptdata->secondary_entries == NULL)
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return 1;
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/* Read data from the drive, skipping the protective MBR */
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if (0 != BootDeviceReadLBA(1, 1, gptdata->primary_header))
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return 1;
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if (0 != BootDeviceReadLBA(2, entries_sectors, gptdata->primary_entries))
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return 1;
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if (0 != BootDeviceReadLBA(gptdata->drive_sectors - entries_sectors - 1,
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entries_sectors, gptdata->secondary_entries))
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return 1;
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if (0 != BootDeviceReadLBA(gptdata->drive_sectors - 1,
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1, gptdata->secondary_header))
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return 1;
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return 0;
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}
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/* Writes any changes for the GPT data back to the drive, then frees
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* the buffers.
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*
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* Returns 0 if successful, 1 if error. */
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int WriteAndFreeGptData(GptData* gptdata) {
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uint64_t entries_sectors = TOTAL_ENTRIES_SIZE / gptdata->sector_bytes;
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if (gptdata->primary_header) {
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if (gptdata->modified & GPT_MODIFIED_HEADER1) {
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if (0 != BootDeviceWriteLBA(1, 1, gptdata->primary_header))
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return 1;
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}
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Free(gptdata->primary_header);
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}
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if (gptdata->primary_entries) {
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if (gptdata->modified & GPT_MODIFIED_ENTRIES1) {
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if (0 != BootDeviceWriteLBA(2, entries_sectors,
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gptdata->primary_entries))
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return 1;
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}
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Free(gptdata->primary_entries);
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}
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if (gptdata->secondary_entries) {
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if (gptdata->modified & GPT_MODIFIED_ENTRIES2) {
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if (0 != BootDeviceWriteLBA(gptdata->drive_sectors - entries_sectors - 1,
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entries_sectors, gptdata->secondary_entries))
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return 1;
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}
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Free(gptdata->secondary_entries);
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}
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if (gptdata->secondary_header) {
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if (gptdata->modified & GPT_MODIFIED_HEADER2) {
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if (0 != BootDeviceWriteLBA(gptdata->drive_sectors - 1, 1,
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gptdata->secondary_header))
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return 1;
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}
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Free(gptdata->secondary_header);
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}
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/* Success */
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return 0;
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}
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int LoadKernel(LoadKernelParams* params) {
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VbPublicKey* kernel_subkey = (VbPublicKey*)params->header_sign_key_blob;
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GptData gpt;
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uint64_t part_start, part_size;
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uint64_t blba = params->bytes_per_lba;
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uint64_t kbuf_sectors = KBUF_SIZE / blba;
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uint8_t* kbuf = NULL;
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int found_partitions = 0;
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int good_partition = -1;
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uint16_t tpm_key_version = 0;
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uint16_t tpm_kernel_version = 0;
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uint64_t lowest_key_version = 0xFFFF;
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uint64_t lowest_kernel_version = 0xFFFF;
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int is_dev = ((BOOT_FLAG_DEVELOPER & params->boot_flags) &&
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!(BOOT_FLAG_RECOVERY & params->boot_flags));
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int is_normal = (!(BOOT_FLAG_DEVELOPER & params->boot_flags) &&
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!(BOOT_FLAG_RECOVERY & params->boot_flags));
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/* Clear output params in case we fail */
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params->partition_number = 0;
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params->bootloader_address = 0;
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params->bootloader_size = 0;
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if (is_normal) {
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/* Read current kernel key index from TPM. Assumes TPM is already
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* initialized. */
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if (0 != GetStoredVersions(KERNEL_VERSIONS,
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&tpm_key_version,
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&tpm_kernel_version)) {
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debug("Unable to get stored version from TPM\n");
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return LOAD_KERNEL_RECOVERY;
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}
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} else if (is_dev) {
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/* In developer mode, we ignore the kernel subkey, and just use
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* the SHA-512 hash to verify the key block. */
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kernel_subkey = NULL;
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}
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do {
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/* Read GPT data */
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gpt.sector_bytes = blba;
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gpt.drive_sectors = params->ending_lba + 1;
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if (0 != AllocAndReadGptData(&gpt)) {
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debug("Unable to read GPT data\n");
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break;
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}
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/* Initialize GPT library */
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if (GPT_SUCCESS != GptInit(&gpt)) {
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debug("Error parsing GPT\n");
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break;
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}
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/* Allocate kernel header buffers */
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kbuf = (uint8_t*)Malloc(KBUF_SIZE);
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if (!kbuf)
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break;
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/* Loop over candidate kernel partitions */
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while (GPT_SUCCESS == GptNextKernelEntry(&gpt, &part_start, &part_size)) {
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VbKeyBlockHeader* key_block;
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VbKernelPreambleHeader* preamble;
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RSAPublicKey* data_key;
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uint64_t key_version;
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uint64_t body_offset;
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debug("Found kernel entry at %" PRIu64 " size %" PRIu64 "\n",
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part_start, part_size);
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/* Found at least one kernel partition. */
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found_partitions++;
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/* Read the first part of the kernel partition */
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if (part_size < kbuf_sectors)
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continue;
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if (0 != BootDeviceReadLBA(part_start, kbuf_sectors, kbuf))
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continue;
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/* Verify the key block */
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key_block = (VbKeyBlockHeader*)kbuf;
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if ((0 != KeyBlockVerify(key_block, KBUF_SIZE, kernel_subkey))) {
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debug("Verifying key block failed.\n");
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continue;
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}
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/* Check the key block flags against the current boot mode */
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if (!(key_block->key_block_flags &&
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((BOOT_FLAG_DEVELOPER & params->boot_flags) ?
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KEY_BLOCK_FLAG_DEVELOPER_1 : KEY_BLOCK_FLAG_DEVELOPER_0))) {
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debug("Developer flag mismatch.\n");
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continue;
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}
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if (!(key_block->key_block_flags &&
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((BOOT_FLAG_RECOVERY & params->boot_flags) ?
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KEY_BLOCK_FLAG_RECOVERY_1 : KEY_BLOCK_FLAG_RECOVERY_0))) {
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debug("Recovery flag mismatch.\n");
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continue;
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}
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/* Check for rollback of key version. Note this is implicitly
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* skipped in recovery and developer modes because those set
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* key_version=0 above. */
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key_version = key_block->data_key.key_version;
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if (key_version < tpm_key_version) {
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debug("Key version too old.\n");
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continue;
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}
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/* Get the key for preamble/data verification from the key block */
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data_key = PublicKeyToRSA(&key_block->data_key);
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if (!data_key)
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continue;
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/* Verify the preamble, which follows the key block */
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preamble = (VbKernelPreambleHeader*)(kbuf + key_block->key_block_size);
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if ((0 != VerifyKernelPreamble2(preamble,
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KBUF_SIZE - key_block->key_block_size,
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data_key))) {
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debug("Preamble verification failed.\n");
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RSAPublicKeyFree(data_key);
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continue;
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}
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/* Check for rollback of kernel version. Note this is implicitly
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* skipped in recovery and developer modes because those set
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* key_version=0 and kernel_version=0 above. */
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if (key_version == tpm_key_version &&
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preamble->kernel_version < tpm_kernel_version) {
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debug("Kernel version too low.\n");
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RSAPublicKeyFree(data_key);
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continue;
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}
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debug("Kernel preamble is good.\n");
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/* Check for lowest key version from a valid header. */
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if (lowest_key_version > key_version) {
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lowest_key_version = key_version;
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lowest_kernel_version = preamble->kernel_version;
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}
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else if (lowest_key_version == key_version &&
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lowest_kernel_version > preamble->kernel_version) {
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lowest_kernel_version = preamble->kernel_version;
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}
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/* If we already have a good kernel, no need to read another
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* one; we only needed to look at the versions to check for
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* rollback. */
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if (-1 != good_partition)
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continue;
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/* Verify body load address matches what we expect */
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if ((preamble->body_load_address != (size_t)params->kernel_buffer) &&
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!(params->boot_flags & BOOT_FLAG_SKIP_ADDR_CHECK)) {
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debug("Wrong body load address.\n");
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RSAPublicKeyFree(data_key);
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continue;
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}
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/* Verify kernel body starts at a multiple of the sector size. */
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body_offset = key_block->key_block_size + preamble->preamble_size;
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if (0 != body_offset % blba) {
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debug("Kernel body not at multiple of sector size.\n");
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RSAPublicKeyFree(data_key);
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continue;
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}
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/* Verify kernel body fits in the partition */
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if (body_offset + preamble->body_signature.data_size >
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part_size * blba) {
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debug("Kernel body doesn't fit in partition.\n");
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RSAPublicKeyFree(data_key);
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continue;
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}
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/* Read the kernel data */
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if (0 != BootDeviceReadLBA(
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part_start + (body_offset / blba),
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(preamble->body_signature.data_size + blba - 1) / blba,
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params->kernel_buffer)) {
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debug("Unable to read kernel data.\n");
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RSAPublicKeyFree(data_key);
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continue;
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}
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/* Verify kernel data */
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if (0 != VerifyData((const uint8_t*)params->kernel_buffer,
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&preamble->body_signature, data_key)) {
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debug("Kernel data verification failed.\n");
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RSAPublicKeyFree(data_key);
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continue;
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}
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/* Done with the kernel signing key, so can free it now */
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RSAPublicKeyFree(data_key);
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/* If we're still here, the kernel is valid. */
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/* Save the first good partition we find; that's the one we'll boot */
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debug("Partiton is good.\n");
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good_partition = gpt.current_kernel;
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params->partition_number = gpt.current_kernel;
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params->bootloader_address = preamble->bootloader_address;
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params->bootloader_size = preamble->bootloader_size;
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/* If we're in developer or recovery mode, there's no rollback
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* protection, so we can stop at the first valid kernel. */
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if (!is_normal)
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break;
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/* Otherwise, we're in normal boot mode, so we do care about the
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* key index in the TPM. If the good partition's key version is
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* the same as the tpm, then the TPM doesn't need updating; we
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* can stop now. Otherwise, we'll check all the other headers
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* to see if they contain a newer key. */
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if (key_version == tpm_key_version &&
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preamble->kernel_version == tpm_kernel_version)
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break;
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} /* while(GptNextKernelEntry) */
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} while(0);
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/* Free kernel buffer */
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if (kbuf)
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Free(kbuf);
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/* Write and free GPT data */
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WriteAndFreeGptData(&gpt);
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/* Handle finding a good partition */
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if (good_partition >= 0) {
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/* See if we need to update the TPM */
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if (is_normal) {
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/* We only update the TPM in normal boot mode. In developer
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* mode, the kernel is self-signed by the developer, so we can't
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* trust the key version and wouldn't want to roll the TPM
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* forward. In recovery mode, the TPM stays PP-unlocked, so
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* anything we write gets blown away by the firmware when we go
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* back to normal mode. */
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if ((lowest_key_version > tpm_key_version) ||
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(lowest_key_version == tpm_key_version &&
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lowest_kernel_version > tpm_kernel_version)) {
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if (0 != WriteStoredVersions(KERNEL_VERSIONS,
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lowest_key_version,
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lowest_kernel_version))
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return LOAD_KERNEL_RECOVERY;
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}
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}
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if (!(BOOT_FLAG_RECOVERY & params->boot_flags)) {
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/* We can lock the TPM now, since we've decided which kernel we
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* like. If we don't find a good kernel, we leave the TPM
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* unlocked so we can try again on the next boot device. If no
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* kernels are good, we'll reboot to recovery mode, so it's ok to
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* leave the TPM unlocked in that case too.
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*
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* If we're already in recovery mode, we need to leave PP unlocked,
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* so don't lock the kernel versions. */
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if (0 != LockKernelVersionsByLockingPP())
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return LOAD_KERNEL_RECOVERY;
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}
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/* Success! */
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return LOAD_KERNEL_SUCCESS;
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}
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// Handle error cases
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if (found_partitions)
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return LOAD_KERNEL_INVALID;
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else
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return LOAD_KERNEL_NOT_FOUND;
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}
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Reference in New Issue
Block a user