def fors_pk_from_sig(self, sig_fors, m, public_seed, adrs: ADRS):
m_int = int.from_bytes(m, 'big')
sigs = self.auths_from_sig_fors(sig_fors)
root = bytes()
for i in range(0, self._k):
idx = (m_int >> (self._k - 1 - i) * self._a) % self._t
sk = sigs[i][0]
adrs.set_tree_height(0)
adrs.set_tree_index(i * self._t + idx)
node_0 = hash(public_seed, adrs.copy(), sk, self._n)
node_1 = 0
auth = sigs[i][1]
adrs.set_tree_index(i * self._t + idx) # Really Useful?
for j in range(0, self._a):
adrs.set_tree_height(j + 1)
if math.floor(idx / 2**j) % 2 == 0:
adrs.set_tree_index(adrs.get_tree_index() // 2)
node_1 = hash(public_seed, adrs.copy(), node_0 + auth[j],
self._n)
else:
adrs.set_tree_index((adrs.get_tree_index() - 1) // 2)
node_1 = hash(public_seed, adrs.copy(), auth[j] + node_0,
self._n)
node_0 = node_1
root += node_0
fors_pk_adrs = adrs.copy()
fors_pk_adrs.set_type(ADRS.FORS_ROOTS)
fors_pk_adrs.set_key_pair_address(adrs.get_key_pair_address())
pk = hash(public_seed, fors_pk_adrs, root, self._n)
return pk
