def spx_verify(self, m, sig, public_key):
adrs = ADRS()
r = sig[0]
sig_fors = sig[1]
sig_ht = sig[2]
public_seed = public_key[0]
public_root = public_key[1]
size_md = math.floor((self._k * self._a + 7) / 8)
size_idx_tree = math.floor((self._h - self._h // self._d + 7) / 8)
size_idx_leaf = math.floor((self._h // self._d + 7) / 8)
digest = hash_msg(r, public_seed, public_root, m, size_md + size_idx_tree + size_idx_leaf)
tmp_md = digest[:size_md]
tmp_idx_tree = digest[size_md:(size_md + size_idx_tree)]
tmp_idx_leaf = digest[(size_md + size_idx_tree):len(digest)]
md_int = int.from_bytes(tmp_md, 'big') >> (len(tmp_md) * 8 - self._k * self._a)
md = md_int.to_bytes(math.ceil(self._k * self._a / 8), 'big')
idx_tree = int.from_bytes(tmp_idx_tree, 'big') >> (len(tmp_idx_tree) * 8 - (self._h - self._h // self._d))
idx_leaf = int.from_bytes(tmp_idx_leaf, 'big') >> (len(tmp_idx_leaf) * 8 - (self._h // self._d))
adrs.set_layer_address(0)
adrs.set_tree_address(idx_tree)
adrs.set_type(ADRS.FORS_TREE)
adrs.set_key_pair_address(idx_leaf)
pk_fors = self.fors_pk_from_sig(sig_fors, md, public_seed, adrs)
adrs.set_type(ADRS.TREE)
return self.ht_verify(pk_fors, sig_ht, public_seed, idx_tree, idx_leaf, public_root)
def ht_verify(self, m, sig_ht, public_seed, idx_tree, idx_leaf, public_key_ht):
adrs = ADRS()
sigs_xmss = self.sigs_xmss_from_sig_ht(sig_ht)
sig_tmp = sigs_xmss[0]
adrs.set_layer_address(0)
adrs.set_tree_address(idx_tree)
node = self.xmss_pk_from_sig(idx_leaf, sig_tmp, m, public_seed, adrs)
for j in range(1, self._d):
idx_leaf = idx_tree % 2 ** self._h_prime
idx_tree = idx_tree >> self._h_prime
sig_tmp = sigs_xmss[j]
adrs.set_layer_address(j)
adrs.set_tree_address(idx_tree)
node = self.xmss_pk_from_sig(idx_leaf, sig_tmp, node, public_seed, adrs)
if node == public_key_ht:
return True
else:
return False
def ht_sign(self, m, secret_seed, public_seed, idx_tree, idx_leaf):
adrs = ADRS()
adrs.set_layer_address(0)
adrs.set_tree_address(idx_tree)
sig_tmp = self.xmss_sign(m, secret_seed, idx_leaf, public_seed,
adrs.copy())
sig_ht = sig_tmp
root = self.xmss_pk_from_sig(idx_leaf, sig_tmp, m, public_seed,
adrs.copy())
for j in range(1, self._d):
idx_leaf = idx_tree % 2**self._h_prime
idx_tree = idx_tree >> self._h_prime
adrs.set_layer_address(j)
adrs.set_tree_address(idx_tree)
sig_tmp = self.xmss_sign(root, secret_seed, idx_leaf, public_seed,
adrs.copy())
sig_ht = sig_ht + sig_tmp
if j < self._d - 1:
root = self.xmss_pk_from_sig(idx_leaf, sig_tmp, root,
public_seed, adrs.copy())
return sig_ht
def spx_sign(self, m, secret_key):
adrs = ADRS()
secret_seed = secret_key[0]
secret_prf = secret_key[1]
public_seed = secret_key[2]
public_root = secret_key[3]
opt = bytes(self._n)
if self._randomize:
opt = os.urandom(self._n)
r = prf_msg(secret_prf, opt, m, self._n)
sig = [r]
size_md = math.floor((self._k * self._a + 7) / 8)
size_idx_tree = math.floor((self._h - self._h // self._d + 7) / 8)
size_idx_leaf = math.floor((self._h // self._d + 7) / 8)
digest = hash_msg(r, public_seed, public_root, m,
size_md + size_idx_tree + size_idx_leaf)
tmp_md = digest[:size_md]
tmp_idx_tree = digest[size_md:(size_md + size_idx_tree)]
tmp_idx_leaf = digest[(size_md + size_idx_tree):len(digest)]
md_int = int.from_bytes(tmp_md,
'big') >> (len(tmp_md) * 8 - self._k * self._a)
md = md_int.to_bytes(math.ceil(self._k * self._a / 8), 'big')
idx_tree = int.from_bytes(tmp_idx_tree,
'big') >> (len(tmp_idx_tree) * 8 -
(self._h - self._h // self._d))
idx_leaf = int.from_bytes(tmp_idx_leaf,
'big') >> (len(tmp_idx_leaf) * 8 -
(self._h // self._d))
adrs.set_layer_address(0)
adrs.set_tree_address(idx_tree)
adrs.set_type(ADRS.FORS_TREE)
adrs.set_key_pair_address(idx_leaf)
sig_fors = self.fors_sign(md, secret_seed, public_seed, adrs.copy())
sig += [sig_fors]
pk_fors = self.fors_pk_from_sig(sig_fors, md, public_seed, adrs.copy())
adrs.set_type(ADRS.TREE)
sig_ht = self.ht_sign(pk_fors, secret_seed, public_seed, idx_tree,
idx_leaf)
sig += [sig_ht]
return sig
def ht_pk_gen(self, secret_seed, public_seed):
adrs = ADRS()
adrs.set_layer_address(self._d - 1)
adrs.set_tree_address(0)
root = self.xmss_pk_gen(secret_seed, public_seed, adrs.copy())
return root
