#!/usr/bin/env python3 import sys import struct import binascii import ed25519 import pyblake2 def sign_data(seckey, data): signkey = ed25519.SigningKey(seckey) digest = pyblake2.blake2s(data).digest() return signkey.sign(digest) def format_sigmask(sigmask): bits = [ str(b + 1) if sigmask & (1<<b) else '.' for b in range(8) ] return '0x%02x = [%s]' % (sigmask, ' '.join(bits)) # bootloader/firmware headers specification: https://github.com/trezor/trezor-core/blob/master/docs/bootloader.md class BinImage: def __init__(self, data, magic, max_size): header = struct.unpack('<4sIIIBBBB427sB64s', data[:512]) self.magic, \ self.hdrlen, \ self.expiry, \ self.codelen, \ self.vmajor, \ self.vminor, \ self.vpatch, \ self.vbuild, \ self.reserved, \ self.sigmask, \ self.sig = header assert self.magic == magic assert self.hdrlen == 512 total_len = self.hdrlen + self.codelen assert total_len % 512 == 0 assert total_len >= 4 * 1024 assert total_len <= max_size assert self.reserved == 427 * b'\x00' self.code = data[self.hdrlen:] assert len(self.code) == self.codelen def print(self): if self.magic == b'TRZF': print('TREZOR Firmware Image') total_len = self.vhdrlen + self.hdrlen + self.codelen elif self.magic == b'TRZB': print('TREZOR Bootloader Image') total_len = self.hdrlen + self.codelen else: print('TREZOR Unknown Image') print(' * magic :', self.magic.decode('ascii')) print(' * hdrlen :', self.hdrlen) print(' * expiry :', self.expiry) print(' * codelen :', self.codelen) print(' * version : %d.%d.%d.%d' % (self.vmajor, self.vminor, self.vpatch, self.vbuild)) print(' * sigmask :', format_sigmask(self.sigmask)) print(' * sig :', binascii.hexlify(self.sig).decode('ascii')) print(' * total : %d bytes' % total_len) print() def serialize_header(self, sig=True): header = struct.pack('<4sIIIBBBB427s', \ self.magic, self.hdrlen, self.expiry, self.codelen, \ self.vmajor, self.vminor, self.vpatch, self.vbuild, \ self.reserved) if sig: header += struct.pack('<B64s', self.sigmask, self.sig) else: header += 65 * b'\x00' assert len(header) == self.hdrlen return header def sign(self, sigmask, seckey): header = self.serialize_header(sig=False) data = header + self.code assert len(data) == self.hdrlen + self.codelen self.sigmask = sigmask self.sig = sign_data(seckey, data) def write(self, filename): with open(filename, 'wb') as f: f.write(self.serialize_header()) f.write(self.code) class FirmwareImage(BinImage): def __init__(self, data, vhdrlen): super().__init__(data[vhdrlen:], magic=b'TRZF', max_size=7*128*1024) self.vhdrlen = vhdrlen self.vheader = data[:vhdrlen] def write(self, filename): with open(filename, 'wb') as f: f.write(self.vheader) f.write(self.serialize_header()) f.write(self.code) class BootloaderImage(BinImage): def __init__(self, data): super().__init__(data, magic=b'TRZB', max_size=64*1024 + 7*128*1024) class VendorHeader: def __init__(self, data): header = struct.unpack('<4sIIBBBB', data[:16]) self.magic, \ self.hdrlen, \ self.expiry, \ self.vmajor, \ self.vminor, \ self.vsig_m, \ self.vsig_n = header assert self.magic == b'TRZV' assert self.vsig_m > 0 and self.vsig_m <= self.vsig_n assert self.vsig_n > 0 and self.vsig_n <= 8 p = 16 self.vpub = [] for _ in range(self.vsig_n): self.vpub.append(data[p:p + 32]) p += 32 self.vstr_len = data[p] p += 1 self.vstr = data[p:p + self.vstr_len] p += self.vstr_len vstr_pad = -p & 3 p += vstr_pad self.vimg_len = len(data) - 65 - p self.vimg = data[p:p + self.vimg_len] p += self.vimg_len self.sigmask = data[p] p += 1 self.sig = data[p:p+64] assert len(data) == 4 + 4 + 4 + 1 + 1 + 1 + 1 + \ 32 * len(self.vpub) + \ 1 + self.vstr_len + vstr_pad + \ self.vimg_len + \ 1 + 64 def print(self): print('TREZOR Vendor Header') print(' * magic :', self.magic.decode('ascii')) print(' * hdrlen :', self.hdrlen) print(' * expiry :', self.expiry) print(' * version : %d.%d' % (self.vmajor, self.vminor)) print(' * scheme : %d out of %d' % (self.vsig_m, self.vsig_n)) for i in range(self.vsig_n): print(' * vpub #%d :' % (i + 1), binascii.hexlify(self.vpub[i]).decode('ascii')) print(' * vstr :', self.vstr.decode('ascii')) print(' * vimg : (%d bytes)' % len(self.vimg)) print(' * sigmask :', format_sigmask(self.sigmask)) print(' * sig :', binascii.hexlify(self.sig).decode('ascii')) def serialize_header(self, sig=True): header = struct.pack('<4sIIBBBB', \ self.magic, self.hdrlen, self.expiry, \ self.vmajor, self.vminor, \ self.vsig_m, self.vsig_n) for i in range(self.vsig_n): header += self.vpub[i] header += struct.pack('<B', self.vstr_len) + self.vstr header += (-len(header) & 3) * b'\x00' # vstr_pad header += self.vimg if sig: header += struct.pack('<B64s', self.sigmask, self.sig) else: header += 65 * b'\x00' assert len(header) == self.hdrlen return header def sign(self, sigmask, seckey): header = self.serialize_header(sig=False) self.sigmask = sigmask self.sig = sign_data(seckey, header) def write(self, filename): with open(filename, 'wb') as f: f.write(self.serialize_header()) def binopen(filename): data = open(filename, 'rb').read() magic = data[:4] if magic == b'TRZB': return BootloaderImage(data) if magic == b'TRZV': vheader = VendorHeader(data) if len(data) == vheader.hdrlen: return vheader subdata = data[vheader.hdrlen:] if subdata[:4] == b'TRZF': return FirmwareImage(data, vheader.hdrlen) if magic == b'TRZF': return FirmwareImage(data, 0) raise Exception('Unknown file format') def main(): if len(sys.argv) < 2: print('Usage: binctl file.bin [-s index seckey]') return 1 fn = sys.argv[1] sign = len(sys.argv) > 2 and sys.argv[2] == '-s' b = binopen(fn) if sign: sigmask = 1 << (int(sys.argv[3]) - 1) seckey = binascii.unhexlify(sys.argv[4]) b.sign(sigmask, seckey) print() b.write(fn) b.print() if __name__ == '__main__': main()