trezor-firmware/tools/keyctl-coordinator

#!/usr/bin/env python3
import binascii
import struct
import click
import pyblake2
import Pyro4
import serpent
from trezorlib import cosi

PORT = 5001
indexmap = {"bootloader": 0, "vendorheader": 1, "firmware": 2}


def header_digest(index, filename):
    data = open(filename, "rb").read()
    z = bytes(65 * [0x00])
    if index == "bootloader":
        header = data[:0x03BF] + z
    elif index == "vendorheader":
        header = data[:-65] + z
    elif index == "firmware":
        vhdrlen = struct.unpack("<I", data[4:8])[0]
        header = data[vhdrlen : vhdrlen + 0x03BF] + z
    else:
        raise ValueError('Unknown index "%s"' % index)
    return pyblake2.blake2s(header).digest()


@click.group()
def cli():
    pass


@cli.command(help="")
@click.argument("index", type=click.Choice(indexmap.keys()))
@click.argument("filename")
@click.argument("participants", nargs=-1)
def sign(index, filename, participants):
    # compute header digest
    digest = header_digest(index, filename)
    # create participant proxies
    if len(participants) < 1:
        raise ValueError("Not enough participants")
    print("connecting to %d participants:" % len(participants))
    proxy = []
    for p in participants:
        uri = "PYRO:keyctl@%s:%d" % (p, PORT)
        proxy.append(Pyro4.Proxy(uri))
    # collect commits
    pks, Rs = [], []
    for i, p in enumerate(proxy):
        pk, R = p.get_commit(index, digest)
        pk, R = serpent.tobytes(pk), serpent.tobytes(R)
        pks.append(pk)
        Rs.append(R)
        print("collected commit #%d from %s" % (i, p._pyroUri.host))
    # compute global commit
    global_pk = cosi.combine_keys(pks)
    global_R = cosi.combine_keys(Rs)
    # collect signatures
    sigs = []
    for i, p in enumerate(proxy):
        sig = p.get_signature(index, digest, global_R, global_pk)
        sig = serpent.tobytes(sig)
        sigs.append(sig)
        print("collected signature #%d from %s" % (i, p._pyroUri.host))
    # compute global signature
    sig = cosi.combine_sig(global_R, sigs)
    cosi.verify(sig, digest, global_pk)
    print("global signature:")
    print(binascii.hexlify(sig).decode())


if __name__ == "__main__":
    cli()