trezor-firmware/core/embed/lib/image.h

/*
 * This file is part of the Trezor project, https://trezor.io/
 *
 * Copyright (c) SatoshiLabs
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef __TREZORHAL_IMAGE_H__
#define __TREZORHAL_IMAGE_H__

#include <stdint.h>
#include "blake2s.h"
#include "flash.h"
#include "image_hash_conf.h"
#include "model.h"
#include "secbool.h"

#define IMAGE_HEADER_SIZE 0x400  // size of the bootloader or firmware header
#define IMAGE_SIG_SIZE 65
#define IMAGE_INIT_CHUNK_SIZE (16 * 1024)

#define BOOTLOADER_IMAGE_MAGIC 0x425A5254  // TRZB

#define FIRMWARE_IMAGE_MAGIC 0x465A5254  // TRZF

typedef struct {
  uint32_t magic;
  uint32_t hdrlen;
  uint32_t expiry;
  uint32_t codelen;
  uint32_t version;
  uint32_t fix_version;
  uint32_t hw_model;
  uint8_t hw_revision;
  uint8_t monotonic;
  uint8_t reserved_0[2];
  uint8_t hashes[512];
  uint8_t reserved_1[415];
  uint8_t sigmask;
  uint8_t sig[64];
} image_header;

#define MAX_VENDOR_PUBLIC_KEYS 8

// The mask of the vendor screen wait time in seconds, encoded in bitwise
// complement form.
#define VTRUST_WAIT_MASK 0x000F

// Use black background instead of red one in the vendor screen.
#define VTRUST_NO_RED 0x0010

// Do not require user click to leave the vendor screen.
#define VTRUST_NO_CLICK 0x0020

// Do not show vendor string in the vendor screen.
#define VTRUST_NO_STRING 0x0040

// Two bits for historical reasons. On T2B1, only the lower bit was used with
// inverted logic (due to late inclusion of the secret handling during
// development process). On T3T1, we decided to remedy the situation by
// including the upper bit as well.
#define VTRUST_SECRET_MASK 0x0180
#define VTRUST_SECRET_ALLOW 0x0100

#define VTRUST_NO_WARNING \
  (VTRUST_WAIT_MASK | VTRUST_NO_RED | VTRUST_NO_CLICK | VTRUST_NO_STRING)

typedef struct {
  uint32_t magic;
  uint32_t hdrlen;
  uint32_t expiry;
  uint16_t version;
  uint8_t vsig_m;
  uint8_t vsig_n;
  uint16_t vtrust;
  // uint8_t reserved[14];
  const uint8_t *vpub[MAX_VENDOR_PUBLIC_KEYS];
  uint8_t vstr_len;
  const char *vstr;
  const uint8_t *vimg;
  uint8_t sigmask;
  uint8_t sig[64];
  const uint8_t *origin;  // pointer to the underlying data
} vendor_header;

typedef struct {
  // vendor string
  uint8_t vstr[64];
  // vendor string length
  size_t vstr_len;
  // firmware version
  uint8_t ver_major;
  uint8_t ver_minor;
  uint8_t ver_patch;
  uint8_t ver_build;
  // firmware fingerprint
  uint8_t fingerprint[IMAGE_HASH_DIGEST_LENGTH];
  // hash of vendor and image header
  uint8_t hash[IMAGE_HASH_DIGEST_LENGTH];
} firmware_header_info_t;

const image_header *read_image_header(const uint8_t *const data,
                                      const uint32_t magic,
                                      const uint32_t maxsize);

secbool __wur check_image_model(const image_header *const hdr);

secbool __wur check_image_header_sig(const image_header *const hdr,
                                     uint8_t key_m, uint8_t key_n,
                                     const uint8_t *const *keys);

secbool __wur read_vendor_header(const uint8_t *const data,
                                 vendor_header *const vhdr);

secbool __wur check_vendor_header_sig(const vendor_header *const vhdr,
                                      uint8_t key_m, uint8_t key_n,
                                      const uint8_t *const *keys);

secbool check_vendor_header_keys(const vendor_header *const vhdr);

void vendor_header_hash(const vendor_header *const vhdr, uint8_t *hash);

secbool __wur check_single_hash(const uint8_t *const hash,
                                const uint8_t *const data, int len);

secbool __wur check_image_contents(const image_header *const hdr,
                                   uint32_t firstskip,
                                   const flash_area_t *area);

void get_image_fingerprint(const image_header *const hdr, uint8_t *const out);

secbool check_firmware_header(const uint8_t *header, size_t header_size,
                              firmware_header_info_t *info);

#endif