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storage.c
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storage.c
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/*
* This file is part of the TREZOR project.
*
* Copyright (C) 2014 Pavol Rusnak <stick@satoshilabs.com>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include <stdint.h>
#include <libopencm3/stm32/flash.h>
#include "messages.pb.h"
#include "storage.pb.h"
#include "trezor.h"
#include "sha2.h"
#include "aes.h"
#include "pbkdf2.h"
#include "bip32.h"
#include "bip39.h"
#include "util.h"
#include "memory.h"
#include "rng.h"
#include "storage.h"
#include "debug.h"
#include "protect.h"
#include "layout2.h"
Storage storage;
uint8_t storage_uuid[12];
char storage_uuid_str[25];
static bool sessionRootNodeCached;
static HDNode sessionRootNode;
static bool sessionPinCached;
static bool sessionPassphraseCached;
static char sessionPassphrase[51];
/*
storage layout:
offset | type/length | description
--------+-------------+-------------------------------
0x0000 | 4 bytes | magic = 'stor'
0x0004 | 12 bytes | uuid
0x0010 | ? | Storage structure
*/
#define STORAGE_VERSION 5
void storage_from_flash(uint32_t version)
{
switch (version) {
case 1: // copy (since 1.0.0)
memcpy(&storage, (void *)(FLASH_STORAGE_START + 4 + sizeof(storage_uuid)), sizeof(Storage));
break;
case 2: // copy (since 1.2.1)
memcpy(&storage, (void *)(FLASH_STORAGE_START + 4 + sizeof(storage_uuid)), sizeof(Storage));
break;
case 3: // copy (since 1.3.1)
memcpy(&storage, (void *)(FLASH_STORAGE_START + 4 + sizeof(storage_uuid)), sizeof(Storage));
break;
case 4: // copy (since 1.3.2)
memcpy(&storage, (void *)(FLASH_STORAGE_START + 4 + sizeof(storage_uuid)), sizeof(Storage));
break;
case 5: // copy (since 1.3.3)
memcpy(&storage, (void *)(FLASH_STORAGE_START + 4 + sizeof(storage_uuid)), sizeof(Storage));
break;
}
storage.version = STORAGE_VERSION;
}
void storage_init(void)
{
storage_reset();
// if magic is ok
if (memcmp((void *)FLASH_STORAGE_START, "stor", 4) == 0) {
// load uuid
memcpy(storage_uuid, (void *)(FLASH_STORAGE_START + 4), sizeof(storage_uuid));
data2hex(storage_uuid, sizeof(storage_uuid), storage_uuid_str);
// load storage struct
uint32_t version = ((Storage *)(FLASH_STORAGE_START + 4 + sizeof(storage_uuid)))->version;
if (version && version <= STORAGE_VERSION) {
storage_from_flash(version);
}
if (version != STORAGE_VERSION) {
storage_commit();
}
} else {
storage_reset_uuid();
storage_commit();
}
}
void storage_reset_uuid(void)
{
// set random uuid
random_buffer(storage_uuid, sizeof(storage_uuid));
data2hex(storage_uuid, sizeof(storage_uuid), storage_uuid_str);
}
void storage_reset(void)
{
// reset storage struct
memset(&storage, 0, sizeof(storage));
storage.version = STORAGE_VERSION;
session_clear(true); // clear PIN as well
}
void session_clear(bool clear_pin)
{
sessionRootNodeCached = false; memset(&sessionRootNode, 0, sizeof(sessionRootNode));
sessionPassphraseCached = false; memset(&sessionPassphrase, 0, sizeof(sessionPassphrase));
if (clear_pin) {
sessionPinCached = false;
}
}
static uint8_t meta_backup[FLASH_META_LEN];
void storage_commit(void)
{
int i;
uint32_t *w;
// backup meta
memcpy(meta_backup, (void *)FLASH_META_START, FLASH_META_LEN);
flash_clear_status_flags();
flash_unlock();
// erase storage
for (i = FLASH_META_SECTOR_FIRST; i <= FLASH_META_SECTOR_LAST; i++) {
flash_erase_sector(i, FLASH_CR_PROGRAM_X32);
}
// modify storage
memcpy(meta_backup + FLASH_META_DESC_LEN, "stor", 4);
memcpy(meta_backup + FLASH_META_DESC_LEN + 4, storage_uuid, sizeof(storage_uuid));
memcpy(meta_backup + FLASH_META_DESC_LEN + 4 + sizeof(storage_uuid), &storage, sizeof(Storage));
// copy it back
for (i = 0; i < FLASH_META_LEN / 4; i++) {
w = (uint32_t *)(meta_backup + i * 4);
flash_program_word(FLASH_META_START + i * 4, *w);
}
flash_lock();
// flash operation failed
if (FLASH_SR & (FLASH_SR_PGAERR | FLASH_SR_PGPERR | FLASH_SR_PGSERR | FLASH_SR_WRPERR)) {
layoutDialog(DIALOG_ICON_ERROR, NULL, NULL, NULL, "Storage failure", "detected.", NULL, "Please unplug", "the device.", NULL);
for (;;) { }
}
}
void storage_loadDevice(LoadDevice *msg)
{
storage_reset();
storage.has_imported = true;
storage.imported = true;
if (msg->has_pin > 0) {
storage_setPin(msg->pin);
}
if (msg->has_passphrase_protection) {
storage.has_passphrase_protection = true;
storage.passphrase_protection = msg->passphrase_protection;
} else {
storage.has_passphrase_protection = false;
}
if (msg->has_node) {
storage.has_node = true;
storage.has_mnemonic = false;
memcpy(&storage.node, &(msg->node), sizeof(HDNodeType));
sessionRootNodeCached = false;
memset(&sessionRootNode, 0, sizeof(sessionRootNode));
} else if (msg->has_mnemonic) {
storage.has_mnemonic = true;
storage.has_node = false;
strlcpy(storage.mnemonic, msg->mnemonic, sizeof(storage.mnemonic));
sessionRootNodeCached = false;
memset(&sessionRootNode, 0, sizeof(sessionRootNode));
}
if (msg->has_language) {
storage_setLanguage(msg->language);
}
if (msg->has_label) {
storage_setLabel(msg->label);
}
}
void storage_setLabel(const char *label)
{
if (!label) return;
storage.has_label = true;
strlcpy(storage.label, label, sizeof(storage.label));
}
void storage_setLanguage(const char *lang)
{
if (!lang) return;
// sanity check
if (strcmp(lang, "english") == 0) {
storage.has_language = true;
strlcpy(storage.language, lang, sizeof(storage.language));
}
}
void storage_setPassphraseProtection(bool passphrase_protection)
{
sessionRootNodeCached = false;
sessionPassphraseCached = false;
storage.has_passphrase_protection = true;
storage.passphrase_protection = passphrase_protection;
}
void storage_setHomescreen(const uint8_t *data, uint32_t size)
{
if (data && size == 1024) {
storage.has_homescreen = true;
memcpy(storage.homescreen.bytes, data, size);
storage.homescreen.size = size;
} else {
storage.has_homescreen = false;
memset(storage.homescreen.bytes, 0, sizeof(storage.homescreen.bytes));
storage.homescreen.size = 0;
}
}
void get_root_node_callback(uint32_t iter, uint32_t total)
{
layoutProgress("Waking up", 1000 * iter / total);
}
bool storage_getRootNode(HDNode *node)
{
// root node is properly cached
if (sessionRootNodeCached) {
memcpy(node, &sessionRootNode, sizeof(HDNode));
return true;
}
// if storage has node, decrypt and use it
if (storage.has_node) {
if (!protectPassphrase()) {
return false;
}
if (hdnode_from_xprv(storage.node.depth, storage.node.fingerprint, storage.node.child_num, storage.node.chain_code.bytes, storage.node.private_key.bytes, &sessionRootNode) == 0) {
return false;
}
if (storage.has_passphrase_protection && storage.passphrase_protection && strlen(sessionPassphrase)) {
// decrypt hd node
uint8_t secret[64];
uint8_t salt[12];
memcpy(salt, "TREZORHD", 8);
layoutProgressSwipe("Waking up", 0);
pbkdf2_hmac_sha512((const uint8_t *)sessionPassphrase, strlen(sessionPassphrase), salt, 8, BIP39_PBKDF2_ROUNDS, secret, 64, get_root_node_callback);
aes_decrypt_ctx ctx;
aes_decrypt_key256(secret, &ctx);
aes_cbc_decrypt(sessionRootNode.chain_code, sessionRootNode.chain_code, 32, secret + 32, &ctx);
aes_cbc_decrypt(sessionRootNode.private_key, sessionRootNode.private_key, 32, secret + 32, &ctx);
}
memcpy(node, &sessionRootNode, sizeof(HDNode));
sessionRootNodeCached = true;
return true;
}
// if storage has mnemonic, convert it to node and use it
if (storage.has_mnemonic) {
if (!protectPassphrase()) {
return false;
}
uint8_t seed[64];
layoutProgressSwipe("Waking up", 0);
mnemonic_to_seed(storage.mnemonic, sessionPassphrase, seed, get_root_node_callback); // BIP-0039
if (hdnode_from_seed(seed, sizeof(seed), &sessionRootNode) == 0) {
return false;
}
memcpy(node, &sessionRootNode, sizeof(HDNode));
sessionRootNodeCached = true;
return true;
}
return false;
}
const char *storage_getLabel(void)
{
return storage.has_label ? storage.label : 0;
}
const char *storage_getLanguage(void)
{
return storage.has_language ? storage.language : 0;
}
const uint8_t *storage_getHomescreen(void)
{
return (storage.has_homescreen && storage.homescreen.size == 1024) ? storage.homescreen.bytes : 0;
}
/* Check whether pin matches storage. The pin must be a null-terminated
* string with at most 9 characters.
*/
bool storage_isPinCorrect(const char *pin)
{
/* The execution time of the following code only depends on the
* (public) input. This avoids timing attacks.
*/
char diff = 0;
uint32_t i = 0;
while (pin[i]) {
diff |= storage.pin[i] - pin[i];
i++;
}
diff |= storage.pin[i];
return diff == 0;
}
bool storage_hasPin(void)
{
return storage.has_pin && storage.pin[0] != 0;
}
void storage_setPin(const char *pin)
{
if (pin && strlen(pin) > 0) {
storage.has_pin = true;
strlcpy(storage.pin, pin, sizeof(storage.pin));
} else {
storage.has_pin = false;
storage.pin[0] = 0;
}
storage_commit();
sessionPinCached = false;
}
void session_cachePassphrase(const char *passphrase)
{
strlcpy(sessionPassphrase, passphrase, sizeof(sessionPassphrase));
sessionPassphraseCached = true;
}
bool session_isPassphraseCached(void)
{
return sessionPassphraseCached;
}
void session_cachePin(void)
{
sessionPinCached = true;
}
bool session_isPinCached(void)
{
return sessionPinCached;
}
void storage_resetPinFails(void)
{
storage.has_pin_failed_attempts = true;
storage.pin_failed_attempts = 0;
storage_commit();
}
void storage_increasePinFails(void)
{
if (!storage.has_pin_failed_attempts) {
storage.has_pin_failed_attempts = true;
storage.pin_failed_attempts = 1;
} else {
storage.pin_failed_attempts++;
}
storage_commit();
}
uint32_t storage_getPinFails(void)
{
storage_from_flash(STORAGE_VERSION); // reload from flash
return storage.has_pin_failed_attempts ? storage.pin_failed_attempts : 0;
}
bool storage_isInitialized(void)
{
return storage.has_node || storage.has_mnemonic;
}