trezor-firmware/legacy/firmware/protect.c

/*
 * This file is part of the Trezor project, https://trezor.io/
 *
 * 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 "protect.h"
#include "buttons.h"
#include "config.h"
#include "debug.h"
#include "fsm.h"
#include "gettext.h"
#include "keyboard.h"
#include "layout2.h"
#include "memory.h"
#include "memzero.h"
#include "messages.h"
#include "messages.pb.h"
#include "oled.h"
#include "pinmatrix.h"
#include "usb.h"
#include "util.h"

bool protectAbortedByCancel = false;
bool protectAbortedByInitialize = false;

bool protectButton(ButtonRequestType type, bool confirm_only) {
  ButtonRequest resp = {0};
  bool result = false;
  bool acked = false;
#if DEBUG_LINK
  bool debug_decided = false;
#endif

  memzero(&resp, sizeof(ButtonRequest));
  resp.has_code = true;
  resp.code = type;
  usbTiny(1);
  buttonUpdate();  // Clear button state
  msg_write(MessageType_MessageType_ButtonRequest, &resp);

  for (;;) {
    usbPoll();

    // check for ButtonAck
    if (msg_tiny_id == MessageType_MessageType_ButtonAck) {
      msg_tiny_id = 0xFFFF;
      acked = true;
    }

    // button acked - check buttons
    if (acked) {
      usbSleep(5);
      buttonUpdate();
      if (button.YesReleased) {
        result = true;
        break;
      }
      if (!confirm_only && button.NoReleased) {
        result = false;
        break;
      }
    }

    // check for Cancel / Initialize
    protectAbortedByCancel = (msg_tiny_id == MessageType_MessageType_Cancel);
    protectAbortedByInitialize =
        (msg_tiny_id == MessageType_MessageType_Initialize);
    if (protectAbortedByCancel || protectAbortedByInitialize) {
      msg_tiny_id = 0xFFFF;
      result = false;
      break;
    }

#if DEBUG_LINK
    // check DebugLink
    if (msg_tiny_id == MessageType_MessageType_DebugLinkDecision) {
      msg_tiny_id = 0xFFFF;
      DebugLinkDecision *dld = (DebugLinkDecision *)msg_tiny;
      result = dld->yes_no;
      debug_decided = true;
    }

    if (acked && debug_decided) {
      break;
    }

    if (msg_tiny_id == MessageType_MessageType_DebugLinkGetState) {
      msg_tiny_id = 0xFFFF;
      fsm_msgDebugLinkGetState((DebugLinkGetState *)msg_tiny);
    }
#endif
  }

  usbTiny(0);

  return result;
}

const char *requestPin(PinMatrixRequestType type, const char *text) {
  return pin_keyboard(text);

  PinMatrixRequest resp = {0};
  memzero(&resp, sizeof(PinMatrixRequest));
  resp.has_type = true;
  resp.type = type;
  usbTiny(1);
  msg_write(MessageType_MessageType_PinMatrixRequest, &resp);
  pinmatrix_start(text);
  for (;;) {
    usbPoll();
    if (msg_tiny_id == MessageType_MessageType_PinMatrixAck) {
      msg_tiny_id = 0xFFFF;
      PinMatrixAck *pma = (PinMatrixAck *)msg_tiny;
      usbTiny(0);
      if (sectrue == pinmatrix_done(pma->pin))  // convert via pinmatrix
        return pma->pin;
      else
        return 0;
    }
    // check for Cancel / Initialize
    protectAbortedByCancel = (msg_tiny_id == MessageType_MessageType_Cancel);
    protectAbortedByInitialize =
        (msg_tiny_id == MessageType_MessageType_Initialize);
    if (protectAbortedByCancel || protectAbortedByInitialize) {
      pinmatrix_done(0);
      msg_tiny_id = 0xFFFF;
      usbTiny(0);
      return 0;
    }
#if DEBUG_LINK
    if (msg_tiny_id == MessageType_MessageType_DebugLinkGetState) {
      msg_tiny_id = 0xFFFF;
      fsm_msgDebugLinkGetState((DebugLinkGetState *)msg_tiny);
    }
#endif
  }
}

secbool protectPinUiCallback(uint32_t wait, uint32_t progress,
                             const char *message) {
  // Convert wait to secstr string.
  char secstrbuf[] = _("________0 seconds");
  char *secstr = secstrbuf + 9;
  uint32_t secs = wait;
  do {
    secstr--;
    *secstr = (secs % 10) + '0';
    secs /= 10;
  } while (secs > 0 && secstr >= secstrbuf);
  if (wait == 1) {
    // Change "seconds" to "second".
    secstrbuf[16] = 0;
  }
  oledClear();
  oledDrawStringCenter(OLED_WIDTH / 2, 0 * 9, message, FONT_STANDARD);
  oledDrawStringCenter(OLED_WIDTH / 2, 2 * 9, _("Please wait"), FONT_STANDARD);
  oledDrawStringCenter(OLED_WIDTH / 2, 3 * 9, secstr, FONT_STANDARD);
  oledDrawStringCenter(OLED_WIDTH / 2, 4 * 9, _("to continue ..."),
                       FONT_STANDARD);
  // progressbar
  oledFrame(0, OLED_HEIGHT - 8, OLED_WIDTH - 1, OLED_HEIGHT - 1);
  oledBox(1, OLED_HEIGHT - 7, OLED_WIDTH - 2, OLED_HEIGHT - 2, 0);
  progress = progress * (OLED_WIDTH - 4) / 1000;
  if (progress > OLED_WIDTH - 4) {
    progress = OLED_WIDTH - 4;
  }
  oledBox(2, OLED_HEIGHT - 6, 1 + progress, OLED_HEIGHT - 3, 1);
  oledRefresh();
  // Check for Cancel / Initialize.
  protectAbortedByCancel = (msg_tiny_id == MessageType_MessageType_Cancel);
  protectAbortedByInitialize =
      (msg_tiny_id == MessageType_MessageType_Initialize);
  if (protectAbortedByCancel || protectAbortedByInitialize) {
    msg_tiny_id = 0xFFFF;
    usbTiny(0);
    fsm_sendFailure(FailureType_Failure_PinCancelled, NULL);
    return sectrue;
  }

  return secfalse;
}

bool protectPin(bool use_cached) {
  if (use_cached && session_isUnlocked()) {
    return true;
  }

  const char *pin = "";
  if (config_hasPin()) {
    pin = requestPin(PinMatrixRequestType_PinMatrixRequestType_Current,
                     _("Please enter current PIN:"));
    if (!pin) {
      fsm_sendFailure(FailureType_Failure_PinCancelled, NULL);
      return false;
    }
  }

  bool ret = config_unlock(pin);
  if (!ret) {
    fsm_sendFailure(FailureType_Failure_PinInvalid, NULL);
  }
  return ret;
}

bool protectChangePin(bool removal) {
  static CONFIDENTIAL char old_pin[MAX_PIN_LEN + 1] = "";
  static CONFIDENTIAL char new_pin[MAX_PIN_LEN + 1] = "";
  const char *pin = NULL;

  if (config_hasPin()) {
    pin = requestPin(PinMatrixRequestType_PinMatrixRequestType_Current,
                     _("Please enter current PIN:"));
    if (pin == NULL) {
      fsm_sendFailure(FailureType_Failure_PinCancelled, NULL);
      return false;
    }

    // If removing, defer the check to config_changePin().
    if (!removal) {
      usbTiny(1);
      bool ret = config_unlock(pin);
      usbTiny(0);
      if (ret == false) {
        fsm_sendFailure(FailureType_Failure_PinInvalid, NULL);
        return false;
      }
    }

    strlcpy(old_pin, pin, sizeof(old_pin));
  }

  if (!removal) {
    pin = requestPin(PinMatrixRequestType_PinMatrixRequestType_NewFirst,
                     _("Please enter new PIN:"));
    if (pin == NULL || pin[0] == '\0') {
      memzero(old_pin, sizeof(old_pin));
      fsm_sendFailure(FailureType_Failure_PinCancelled, NULL);
      return false;
    }
    strlcpy(new_pin, pin, sizeof(new_pin));

    pin = requestPin(PinMatrixRequestType_PinMatrixRequestType_NewSecond,
                     _("Please re-enter new PIN:"));
    if (pin == NULL) {
      memzero(old_pin, sizeof(old_pin));
      memzero(new_pin, sizeof(new_pin));
      fsm_sendFailure(FailureType_Failure_PinCancelled, NULL);
      return false;
    }

    if (strncmp(new_pin, pin, sizeof(new_pin)) != 0) {
      memzero(old_pin, sizeof(old_pin));
      memzero(new_pin, sizeof(new_pin));
      fsm_sendFailure(FailureType_Failure_PinMismatch, NULL);
      return false;
    }
  }

  bool ret = config_changePin(old_pin, new_pin);
  memzero(old_pin, sizeof(old_pin));
  memzero(new_pin, sizeof(new_pin));
  if (ret == false) {
    if (removal) {
      fsm_sendFailure(FailureType_Failure_PinInvalid, NULL);
    } else {
      fsm_sendFailure(FailureType_Failure_ProcessError,
                      _("The new PIN must be different from your wipe code."));
    }
  }
  return ret;
}

bool protectChangeWipeCode(bool removal) {
  static CONFIDENTIAL char pin[MAX_PIN_LEN + 1] = "";
  static CONFIDENTIAL char wipe_code[MAX_PIN_LEN + 1] = "";
  const char *input = NULL;

  if (config_hasPin()) {
    input = requestPin(PinMatrixRequestType_PinMatrixRequestType_Current,
                       _("Please enter your PIN:"));
    if (input == NULL) {
      fsm_sendFailure(FailureType_Failure_PinCancelled, NULL);
      return false;
    }

    // If removing, defer the check to config_changeWipeCode().
    if (!removal) {
      usbTiny(1);
      bool ret = config_unlock(input);
      usbTiny(0);
      if (ret == false) {
        fsm_sendFailure(FailureType_Failure_PinInvalid, NULL);
        return false;
      }
    }

    strlcpy(pin, input, sizeof(pin));
  }

  if (!removal) {
    input = requestPin(PinMatrixRequestType_PinMatrixRequestType_WipeCodeFirst,
                       _("Enter new wipe code:"));
    if (input == NULL) {
      memzero(pin, sizeof(pin));
      fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
      return false;
    }
    if (strncmp(pin, input, sizeof(pin)) == 0) {
      memzero(pin, sizeof(pin));
      fsm_sendFailure(FailureType_Failure_ProcessError,
                      _("The wipe code must be different from your PIN."));
      return false;
    }
    strlcpy(wipe_code, input, sizeof(wipe_code));

    input = requestPin(PinMatrixRequestType_PinMatrixRequestType_WipeCodeSecond,
                       _("Re-enter new wipe code:"));
    if (input == NULL) {
      memzero(pin, sizeof(pin));
      memzero(wipe_code, sizeof(wipe_code));
      fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
      return false;
    }

    if (strncmp(wipe_code, input, sizeof(wipe_code)) != 0) {
      memzero(pin, sizeof(pin));
      memzero(wipe_code, sizeof(wipe_code));
      fsm_sendFailure(FailureType_Failure_WipeCodeMismatch, NULL);
      return false;
    }
  }

  bool ret = config_changeWipeCode(pin, wipe_code);
  memzero(pin, sizeof(pin));
  memzero(wipe_code, sizeof(wipe_code));
  if (ret == false) {
    fsm_sendFailure(FailureType_Failure_PinInvalid, NULL);
  }
  return ret;
}

static bool protectPassphraseOnDevice(char *passphrase) {
  const char *input = passphrase_keyboard(_("Please enter passphrase"));
  if (input) {
    strlcpy(passphrase, input, MAX_PASSPHRASE_LEN);
    return true;
  } else {
    fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
    return false;
  }
}

static bool protectPassphraseOnHost(char *passphrase) {
  PassphraseRequest resp = {0};
  memzero(&resp, sizeof(PassphraseRequest));
  usbTiny(1);
  msg_write(MessageType_MessageType_PassphraseRequest, &resp);

  layoutDialogSwipe(&bmp_icon_info, NULL, NULL, NULL, _("Please enter your"),
                    _("passphrase using"), _("the computer's"), _("keyboard."),
                    NULL, NULL);

  bool result;
  for (;;) {
    usbPoll();
    if (msg_tiny_id == MessageType_MessageType_PassphraseAck) {
      msg_tiny_id = 0xFFFF;
      PassphraseAck *ppa = (PassphraseAck *)msg_tiny;
      if (ppa->has_on_device && ppa->on_device == true) {
        if (ppa->has_passphrase) {
          fsm_sendFailure(FailureType_Failure_DataError,
                          _("Passphrase provided when it should not be"));
          result = false;
          break;
        }
        result = protectPassphraseOnDevice(passphrase);
        break;
      }
      if (!ppa->has_passphrase) {
        fsm_sendFailure(FailureType_Failure_DataError,
                        _("No passphrase provided. Use empty string to set an "
                          "empty passphrase."));
        result = false;
        break;
      }
      strlcpy(passphrase, ppa->passphrase, sizeof(ppa->passphrase));
      if (passphrase[0] != '\0') {
        // passphrase is used - confirm on the display
        layoutDialogSwipe(&bmp_icon_question, _("Cancel"), _("Confirm"), NULL,
                          _("Access hidden wallet?"), NULL,
                          _("Next screen will show"), _("the passphrase!"),
                          NULL, NULL);
        if (!protectButton(ButtonRequestType_ButtonRequest_Other, false)) {
          fsm_sendFailure(FailureType_Failure_ActionCancelled,
                          _("Passphrase dismissed"));
          result = false;
          break;
        }
        layoutShowPassphrase(passphrase);
        if (!protectButton(ButtonRequestType_ButtonRequest_Other, false)) {
          fsm_sendFailure(FailureType_Failure_ActionCancelled,
                          _("Passphrase dismissed"));
          result = false;
          break;
        }
      }
      result = true;
      break;
    }
    // check for Cancel / Initialize
    protectAbortedByCancel = (msg_tiny_id == MessageType_MessageType_Cancel);
    protectAbortedByInitialize =
        (msg_tiny_id == MessageType_MessageType_Initialize);
    if (protectAbortedByCancel || protectAbortedByInitialize) {
      fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
      result = false;
      msg_tiny_id = 0xFFFF;
      break;
    }
  }
  usbTiny(0);
  layoutHome();
  return result;
}

bool protectPassphrase(char *passphrase) {
  memzero(passphrase, MAX_PASSPHRASE_LEN + 1);
  bool passphrase_protection = false;
  config_getPassphraseProtection(&passphrase_protection);
  if (!passphrase_protection) {
    // passphrase already set to empty by memzero above
    return true;
  }

  if (config_getPassphraseAlwaysOnDevice()) {
    return protectPassphraseOnDevice(passphrase);
  } else {
    return protectPassphraseOnHost(passphrase);
  }
}