eth2.0-specs/tests/core/pyspec/eth2spec/utils/bls.py

147 lines
3.5 KiB
Python

from py_ecc.bls import G2ProofOfPossession as py_ecc_bls
from py_ecc.bls.g2_primatives import signature_to_G2 as _signature_to_G2
from py_ecc.optimized_bls12_381 import ( # noqa: F401
G1,
G2,
Z1,
Z2,
FQ,
add,
multiply,
neg,
pairing,
final_exponentiate,
FQ12
)
from py_ecc.bls.g2_primitives import ( # noqa: F401
G1_to_pubkey as G1_to_bytes48,
pubkey_to_G1 as bytes48_to_G1,
G2_to_signature as G2_to_bytes96,
signature_to_G2 as bytes96_to_G2,
)
import milagro_bls_binding as milagro_bls # noqa: F401 for BLS switching option
# Flag to make BLS active or not. Used for testing, do not ignore BLS in production unless you know what you are doing.
bls_active = True
# To change bls implementation, default to PyECC for correctness. Milagro is a good faster alternative.
bls = py_ecc_bls
STUB_SIGNATURE = b'\x11' * 96
STUB_PUBKEY = b'\x22' * 48
G2_POINT_AT_INFINITY = b'\xc0' + b'\x00' * 95
STUB_COORDINATES = _signature_to_G2(G2_POINT_AT_INFINITY)
def use_milagro():
"""
Shortcut to use Milagro as BLS library
"""
global bls
bls = milagro_bls
def use_py_ecc():
"""
Shortcut to use Py-ecc as BLS library
"""
global bls
bls = py_ecc_bls
def only_with_bls(alt_return=None):
"""
Decorator factory to make a function only run when BLS is active. Otherwise return the default.
"""
def runner(fn):
def entry(*args, **kw):
if bls_active:
return fn(*args, **kw)
else:
return alt_return
return entry
return runner
@only_with_bls(alt_return=True)
def Verify(PK, message, signature):
try:
result = bls.Verify(PK, message, signature)
except Exception:
result = False
finally:
return result
@only_with_bls(alt_return=True)
def AggregateVerify(pubkeys, messages, signature):
try:
result = bls.AggregateVerify(list(pubkeys), list(messages), signature)
except Exception:
result = False
finally:
return result
@only_with_bls(alt_return=True)
def FastAggregateVerify(pubkeys, message, signature):
try:
result = bls.FastAggregateVerify(list(pubkeys), message, signature)
except Exception:
result = False
finally:
return result
@only_with_bls(alt_return=STUB_SIGNATURE)
def Aggregate(signatures):
return bls.Aggregate(signatures)
@only_with_bls(alt_return=STUB_SIGNATURE)
def Sign(SK, message):
if bls == py_ecc_bls:
return bls.Sign(SK, message)
else:
return bls.Sign(SK.to_bytes(32, 'big'), message)
@only_with_bls(alt_return=STUB_COORDINATES)
def signature_to_G2(signature):
return _signature_to_G2(signature)
@only_with_bls(alt_return=STUB_PUBKEY)
def AggregatePKs(pubkeys):
if bls == py_ecc_bls:
assert all(bls.KeyValidate(pubkey) for pubkey in pubkeys)
elif bls == milagro_bls:
# milagro_bls._AggregatePKs checks KeyValidate internally
pass
return bls._AggregatePKs(list(pubkeys))
@only_with_bls(alt_return=STUB_SIGNATURE)
def SkToPk(SK):
if bls == py_ecc_bls:
return bls.SkToPk(SK)
else:
return bls.SkToPk(SK.to_bytes(32, 'big'))
def pairing_check(values):
p_q_1, p_q_2 = values
final_exponentiation = final_exponentiate(
pairing(p_q_1[1], p_q_1[0], final_exponentiate=False)
* pairing(p_q_2[1], p_q_2[0], final_exponentiate=False)
)
return final_exponentiation == FQ12.one()
@only_with_bls(alt_return=True)
def KeyValidate(pubkey):
return py_ecc_bls.KeyValidate(pubkey)