def verify(SIG, m, W):
HM = BLS_H(m)
D = ECp()
D.fromBytes(SIG)
if D.isinf():
return False
if not (curve.r * D).isinf():
return False
D = -D
PK = ECp2()
PK.fromBytes(W)
# Use new multi-pairing mechanism
r = pair.initmp()
pair.another_pc(r, G2_TAB, D)
pair.another(r, PK, HM)
v = pair.miller(r)
#.. or alternatively
# G=ecp2.generator()
# if G.isinf() :
# return False
# v = pair.double_ate(G, D, PK, HM)
v = pair.fexp(v)
if v.isone():
return True
return False
def ECP_SvdpDH(S, W):
s = big.from_bytes(S)
WP = ECp()
if not WP.fromBytes(W):
return ECDH_ERROR
r = curve.r
s %= r
WP = s * WP
if WP.isinf():
return ECDH_ERROR
x = WP.getx()
K = big.to_bytes(x)
return K
def ECP_PublicKeyValidate(W):
r = curve.r
p = curve.p
WP = ECp()
if not WP.fromBytes(W):
return ECDH_INVALID_PUBLIC_KEY
nb = p.bit_length()
k = 1
k = k << (nb + 4) // 2
k += p
k //= r
while k % 2 == 0:
WP.dbl()
k //= 2
if k != 1:
WP = k * WP
if WP.isinf():
return ECDH_INVALID_PUBLIC_KEY
return 0