Momentum-Apps

FlipBIP - BIP32/39/44

Crypto toolkit for Flipper Zero

• Built against 0.78.1 Flipper Zero firmware release
• Using Trezor crypto libs from core/v2.5.3 release
• Included in RogueMaster Custom Firmware

DONATE IF YOU FIND THE APP USEFUL

• ETH (or ERC-20): xtruan.eth or 0xa9Ad79502cdaf4F6881f3C2ef260713e5B771CE2
• BTC: 16RP5Ui5QrWrVh2rR7NKAPwE5A4uFjCfbs

Background

The goal of this project is to see how much crypto functionality can be brought to the Flipper Zero.

How to install on Flipper Zero

• If you do not have one, download a Flipper Zero firmware to get the fbt build tool
• Plug your Flipper Zero in via USB
• Copy the contents of this folder into the applications_user folder of your firmware
• Modify the site_scons/cc.scons file in the Flipper Zero firmware to add the "-Os" flag

Then run the command:

./fbt COMPACT=1 DEBUG=0 launch_app APPSRC=applications_user/FlipBIP

The application will be compiled and copied onto your device

Status

Complete

• Trezor crypto C code ported into crypto subfolder
  • Adapted to use Flipper hardware RNG (see crypto/rand.c)
  • Imports and some C library functions modified for compatibility with FBT
• Navigation and UI adapted from FAP Boilerplate app
• BIP39 mnemonic generation
  • 24, 18, or 12 words configured in settings
• BIP39 mnemonic to BIP39 seed generation
• Hierarchical Deterministic (HD) wallet generation from seed
  • Generation of offline m/44'/0'/0'/0 BTC wallet
  • Generation of offline m/44'/60'/0'/0 ETH wallet (coded from the $SPORK Castle of ETHDenver 2023!)
  • Generation of offline m/44'/3'/0'/0 DOGE wallet
  • Similar features to: https://iancoleman.io/bip39/
• Saving wallets to SD card
  • Wallets are saved to SD card upon creation in apps_data/flipbip
    • NOTE: apps_data folder must already exist on SD card!
  • Saved wallets can be viewed between app runs
  • Wallets are encrypted with a randomly generated key, and that key is also encrypted
    • .flipbip.dat and .flipbip.key files are both required to be in apps_data/flipbip
    • Backups of both these files .flipbip.dat.bak and .flipbip.key.bak are also maintained
    • If you want to externally back up your wallet, I recommend copying all these files, and storing the key and dat files seperately
  • NOTE: The wallets should be decently tough to crack off of a Flipper, however any Flipper with the app installed can load a wallet in the apps_data/flipbip directory if both the key and dat file are present
• BIP39 passphrase support
  • Configured in settings, not persisted between runs for security
• Import your own mnemonic
  • Lots of typing required but you can now use the wallet with an existing mnemonic you have saved
  • Useful to convert paper backup to keys and receive addresses without relying on a laptop or phone
• Improved receive address generation features
  • Addresses are now generated at the same time as other pieces of wallet info
  • This slows down initial wallet load, but makes UI much more responsive
  • QR code files are now generated for each address and stored in the apps_data/flipbip directory
  • This app is required to view the QR code files: https://github.com/bmatcuk/flipperzero-qrcode (included in RM firmware)
  • NOTE: This happens during the View Wallet step; you must view a wallet after generating/importing a wallet in order to ensure the address QR files are correct
• Broke out crypto functionality into its own library using fap_private_libs feature

Work in Progress

• More coin types
  • Support for more custom BIP32 wallet paths

(FAR) Future

• Custom wallet security
  • User specified password
• USB/Bluetooth wallet functionality