diff options
Diffstat (limited to 'futility/ryu_root_header.c')
-rw-r--r-- | futility/ryu_root_header.c | 165 |
1 files changed, 0 insertions, 165 deletions
diff --git a/futility/ryu_root_header.c b/futility/ryu_root_header.c deleted file mode 100644 index ef005311..00000000 --- a/futility/ryu_root_header.c +++ /dev/null @@ -1,165 +0,0 @@ -/* Copyright 2015 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. - */ - -#include <errno.h> -#include <getopt.h> -#include <inttypes.h> -#include <stddef.h> -#include <stdint.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <sys/stat.h> -#include <sys/types.h> -#include <unistd.h> - -#include "2common.h" -#include "2sha.h" -#include "2sysincludes.h" -#include "futility.h" - -#define SEARCH_STRIDE 4 - -/** - * Check if the pointer contains the magic string. We need to use a - * case-swapped version, so that the actual magic string doesn't appear in the - * code, to avoid falsely finding it when searching for the struct. - */ -static int is_magic(const void *ptr) -{ - const char magic_inv[RYU_ROOT_KEY_HASH_MAGIC_SIZE] = - RYU_ROOT_KEY_HASH_MAGIC_INVCASE; - const char *magic = ptr; - int i; - - for (i = 0; i < RYU_ROOT_KEY_HASH_MAGIC_SIZE; i++) { - if (magic[i] != (magic_inv[i] ^ 0x20)) - return 0; - } - - return 1; -} - -static int valid_ryu_root_header(struct vb2_ryu_root_key_hash *hash, - size_t size) -{ - if (!is_magic(hash->magic)) - return 0; /* Wrong magic */ - - if (hash->header_version_major != RYU_ROOT_KEY_HASH_VERSION_MAJOR) - return 0; /* Version we can't parse */ - - if (hash->struct_size < EXPECTED_VB2_RYU_ROOT_KEY_HASH_SIZE) - return 0; /* Header too small */ - - if (hash->struct_size > size) - return 0; /* Claimed size doesn't fit in buffer */ - - return 1; -} - -/** - * Find the root key hash struct and return it or NULL if error. - */ -static struct vb2_ryu_root_key_hash *find_ryu_root_header(uint8_t *ptr, - size_t size) -{ - size_t i; - struct vb2_ryu_root_key_hash *tmp, *hash = NULL; - int count = 0; - - /* Look for the ryu root key hash header */ - for (i = 0; i <= size - SEARCH_STRIDE; i += SEARCH_STRIDE) { - if (!is_magic(ptr + i)) - continue; - - /* Found something. See if it's any good. */ - tmp = (struct vb2_ryu_root_key_hash *) (ptr + i); - if (valid_ryu_root_header(tmp, size - i)) - if (!count++) - hash = tmp; - } - - switch (count) { - case 0: - return NULL; - case 1: - return hash; - default: - fprintf(stderr, - "WARNING: multiple ryu root hash headers found\n"); - /* But hey, it's only a warning. Use the first one. */ - return hash; - } -} - -static void calculate_root_key_hash(uint8_t *digest, size_t digest_size, - const struct vb2_gbb_header *gbb) -{ - const uint8_t *gbb_base = (const uint8_t *)gbb; - - vb2_digest_buffer(gbb_base + gbb->rootkey_offset, - gbb->rootkey_size, - VB2_HASH_SHA256, - digest, - digest_size); -} - -int fill_ryu_root_header(uint8_t *ptr, size_t size, - const struct vb2_gbb_header *gbb) -{ - struct vb2_ryu_root_key_hash *hash; - - /* - * Find the ryu root header. If not found, nothing we can do, but - * that's ok because most images don't have the header. - */ - hash = find_ryu_root_header(ptr, size); - if (!hash) - return 0; - - /* Update the hash stored in the header based on the root key */ - calculate_root_key_hash(hash->root_key_hash_digest, - sizeof(hash->root_key_hash_digest), - gbb); - - printf(" - calculate ryu root hash: success\n"); - return 0; -} - -int verify_ryu_root_header(uint8_t *ptr, size_t size, - const struct vb2_gbb_header *gbb) -{ - uint8_t digest[VB2_SHA256_DIGEST_SIZE] = {0}; - - struct vb2_ryu_root_key_hash *hash; - - /* - * Find the ryu root header. If not found, nothing we can do, but - * that's ok because most images don't have the header. - */ - hash = find_ryu_root_header(ptr, size); - if (!hash) { - printf(" - ryu root hash not found\n"); - return 0; - } - - /* Check for all 0's, which means hash hasn't been set */ - if (0 == memcmp(digest, hash->root_key_hash_digest, sizeof(digest))) { - printf(" - ryu root hash is unset\n"); - return 0; - } - - /* Update the hash stored in the header based on the root key */ - calculate_root_key_hash(digest, sizeof(digest), gbb); - - if (0 == memcmp(digest, hash->root_key_hash_digest, sizeof(digest))) { - printf(" - ryu root hash verified\n"); - return 0; - } else { - printf(" - ryu root hash does not verify\n"); - return -1; - } -} |