mirror of
https://gitlab.com/pulsechaincom/staking-deposit-cli.git
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9557f3cabb
* Tests are of type none. * Parameters passed in to tests instead of using global variables * remove debugging print left in Co-authored-by: Hsiao-Wei Wang <hwwang156@gmail.com>
60 lines
1.8 KiB
Python
60 lines
1.8 KiB
Python
from eth2deposit.utils.crypto import (
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HKDF,
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SHA256,
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)
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from py_ecc.optimized_bls12_381 import curve_order as bls_curve_order
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from typing import List
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def _flip_bits_256(input: int) -> int:
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"""
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Flips 256 bits worth of `input`.
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"""
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return input ^ (2**256 - 1)
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def _IKM_to_lamport_SK(*, IKM: bytes, salt: bytes) -> List[bytes]:
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"""
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Derives the lamport SK for a given `IKM` and `salt`.
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"""
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OKM = HKDF(salt=salt, IKM=IKM, L=8160)
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lamport_SK = [OKM[i: i + 32] for i in range(0, 8160, 32)]
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return lamport_SK
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def _parent_SK_to_lamport_PK(*, parent_SK: int, index: int) -> bytes:
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"""
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Derives the `index`th child's lamport PK from the `parent_SK`.
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"""
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salt = index.to_bytes(4, byteorder='big')
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IKM = parent_SK.to_bytes(32, byteorder='big')
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lamport_0 = _IKM_to_lamport_SK(IKM=IKM, salt=salt)
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not_IKM = _flip_bits_256(parent_SK).to_bytes(32, byteorder='big')
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lamport_1 = _IKM_to_lamport_SK(IKM=not_IKM, salt=salt)
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lamport_SKs = lamport_0 + lamport_1
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lamport_PKs = [SHA256(sk) for sk in lamport_SKs]
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compressed_PK = SHA256(b''.join(lamport_PKs))
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return compressed_PK
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def _HKDF_mod_r(*, IKM: bytes, key_info: bytes=b'') -> int:
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L = 48 # `ceil((3 * ceil(log2(r))) / 16)`, where `r` is the order of the BLS 12-381 curve
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okm = HKDF(
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salt=b'BLS-SIG-KEYGEN-SALT-',
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IKM=IKM + b'\x00', # add postfix `I2OSP(0, 1)`
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L=L,
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info=key_info + L.to_bytes(2, 'big'),
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)
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return int.from_bytes(okm, byteorder='big') % bls_curve_order
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def derive_child_SK(*, parent_SK: int, index: int) -> int:
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assert(index >= 0 and index < 2**32)
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lamport_PK = _parent_SK_to_lamport_PK(parent_SK=parent_SK, index=index)
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return _HKDF_mod_r(IKM=lamport_PK)
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def derive_master_SK(seed: bytes) -> int:
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assert(len(seed) >= 32)
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return _HKDF_mod_r(IKM=seed)
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