mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-22 06:18:07 +00:00
15bd35824b
cosi.verify was renamed to verify_combined, because it is pretty much ed25519.verify, and the new name implies what it does in terms of the CoSi scheme: verify a signature with already-combined public keys. cosi.verify_m_of_n signature was simplified by not requiring the `n` parameter, which is not important for verification. The updated function was renamed to cosi.verify, because this is the standard CoSi verification operation: given signature, digest, required number of signatures, sigmask, and a list of public keys, verify that enough signatures are indicated and that they sign the digest.
64 lines
1.7 KiB
Python
Executable File
64 lines
1.7 KiB
Python
Executable File
#!/usr/bin/env python3
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import binascii
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import struct
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import click
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import pyblake2
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from trezorlib import cosi
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indexmap = {"bootloader": 0, "vendorheader": 1, "firmware": 2}
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def header_digest(index, filename):
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data = open(filename, "rb").read()
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z = bytes(65 * [0x00])
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if index == "bootloader":
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header = data[:0x03BF] + z
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elif index == "vendorheader":
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header = data[:-65] + z
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elif index == "firmware":
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vhdrlen = struct.unpack("<I", data[4:8])[0]
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header = data[vhdrlen : vhdrlen + 0x03BF] + z
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else:
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raise ValueError('Unknown index "%s"' % index)
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return pyblake2.blake2s(header).digest()
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@click.group()
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def cli():
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pass
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@cli.command(help="")
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@click.argument("index", type=click.Choice(indexmap.keys()))
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@click.argument("filename")
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@click.argument("seckeys", nargs=-1)
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def sign(index, filename, seckeys):
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# compute header digest
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digest = header_digest(index, filename)
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# collect commits
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pks, nonces, Rs = [], [], []
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for ctr, seckey in enumerate(seckeys):
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sk = binascii.unhexlify(seckey)
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pk = cosi.pubkey_from_privkey(sk)
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r, R = cosi.get_nonce(sk, digest, ctr)
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pks.append(pk)
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nonces.append(r)
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Rs.append(R)
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# compute global commit
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global_pk = cosi.combine_keys(pks)
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global_R = cosi.combine_keys(Rs)
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# collect signatures
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sigs = []
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for seckey, nonce in zip(seckeys, nonces):
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sk = binascii.unhexlify(seckey)
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sig = cosi.sign_with_privkey(digest, sk, global_pk, nonce, global_R)
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sigs.append(sig)
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# compute global signature
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sig = cosi.combine_sig(global_R, sigs)
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cosi.verify_combined(sig, digest, global_pk)
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print(binascii.hexlify(sig).decode())
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if __name__ == "__main__":
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cli()
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