Implement other parameters

Author: azuchi

lib/wots.rb

@@ -10,22 +10,4 @@
 
 module WOTS
   class Error < StandardError; end
-
-  # Check whether +data+ is hex string or not.
-  # @param [String] data
-  # @return [Boolean]
-  # @raise [ArgumentError]
-  def hex_string?(data)
-    raise ArgumentError, 'data must be string' unless data.is_a?(String)
-    data.match?(/\A[0-9a-fA-F]+\z/)
-  end
-
-  # Convert hex string +data+ to binary.
-  # @param [String] data
-  # @return [String]
-  # @raise [ArgumentError]
-  def hex_to_bin(data)
-    raise ArgumentError, 'data must be string' unless data.is_a?(String)
-    hex_string?(data) ? [data].pack('H*') : data
-  end
 end

lib/wots/param.rb

@@ -1,3 +1,5 @@
+require 'openssl'
+
 module WOTS
   # WOTS+ parameters defined in rfc8391.
   # https://datatracker.ietf.org/doc/html/rfc8391
@@ -7,7 +9,6 @@ class Param
     autoload :SHA256, 'wots/param/sha256'
     autoload :SHA512, 'wots/param/sha512'
     autoload :SHAKE256, 'wots/param/shake256'
-    autoload :SHAKE512, 'wots/param/shake512'
 
     attr_reader :name
     attr_reader :n
@@ -160,11 +161,14 @@ def xor_bytes(a, b)
     end
 
     def keyed_hash(prefix, k, m)
+      payload = to_byte(prefix, n) + hex_to_bin(k) + hex_to_bin(m)
       case name
-      when 'wotsp-sha2_256'
-        Digest::SHA256.hexdigest(to_byte(prefix, 32) + hex_to_bin(k) + hex_to_bin(m))
-      when 'wotsp-sha512'
-        Digest::SHA512.hexdigest(to_byte(prefix, 64) + hex_to_bin(k) + hex_to_bin(m))
+      when 'WOTSP-SHA2_256'
+        Digest::SHA256.hexdigest(payload)
+      when 'WOTSP-SHA2_512'
+        Digest::SHA512.hexdigest(payload)
+      when 'WOTSP-SHAKE_256'
+        OpenSSL::Digest.new('shake256', payload).hexdigest
       else
         raise 'Unknown param'
       end

lib/wots/param/sha256.rb

@@ -1,7 +1,7 @@
 module WOTS
   class Param
     SHA256 = new(
-      name: 'wotsp-sha2_256',
+      name: 'WOTSP-SHA2_256',
       n: 32,
       w: 16
     )

lib/wots/param/sha512.rb

@@ -1,7 +1,7 @@
 module WOTS
   class Param
     SHA512 = new(
-      name: 'wotsp-sha512',
+      name: 'WOTSP-SHA2_512',
       n: 64,
       w: 16
     )

lib/wots/param/shake256.rb

@@ -1,7 +1,7 @@
 module WOTS
   class Param
     SHAKE256 = new(
-      name: 'wotsp-shake_256',
+      name: 'WOTSP-SHAKE_256',
       n: 32,
       w: 16
     )

lib/wots/param/shake512.rb

@@ -2,13 +2,14 @@ module WOTS
   # WOTS+ private key.
   class PrivateKey
     include Util
+    extend Util
 
     attr_reader :param
     attr_reader :keys
 
     def initialize(param, keys)
-      raise ArgumentError "param must be WOTS::Param." unless param.is_a?(WOTS::Param)
-      raise ArgumentError "keys must be Array." unless keys.is_a?(Array)
+      raise ArgumentError, "param must be WOTS::Param." unless param.is_a?(WOTS::Param)
+      raise ArgumentError, "keys must be Array." unless keys.is_a?(Array)
       raise ArgumentError, "The length of keys must be the same as param#len." unless keys.length == param.len
       keys.each do |key|
         raise ArgumentError, "key must be hex string." unless hex_string?(key)
@@ -24,9 +25,10 @@ def initialize(param, keys)
     # @param [String] seed
     # @raise ArgumentError
     def self.from_seed(param, seed)
-      raise ArgumentError "param must be WOTS::Param." unless param.is_a?(WOTS::Param)
-      raise ArgumentError "seed must be String." unless seed.is_a?(String)
-      raise ArgumentError "len parameter too large." if param.len.bit_length > 16
+      raise ArgumentError, "param must be WOTS::Param." unless param.is_a?(WOTS::Param)
+      raise ArgumentError, "seed must be String." unless seed.is_a?(String)
+      raise ArgumentError, "seed must be #{param.n} bytes." unless hex_to_bin(seed).bytesize == param.n
+      raise ArgumentError, "len parameter too large." if param.len.bit_length > 16
 
       keys = param.len.times.map do |i|
         param.prf(seed, param.to_byte(i, 32))

lib/wots/private_key.rb

@@ -8,8 +8,8 @@ class PublicKey
     attr_reader :keys
 
     def initialize(param, keys)
-      raise ArgumentError "param must be WOTS::Param." unless param.is_a?(WOTS::Param)
-      raise ArgumentError "keys must be Array." unless keys.is_a?(Array)
+      raise ArgumentError, "param must be WOTS::Param." unless param.is_a?(WOTS::Param)
+      raise ArgumentError, "keys must be Array." unless keys.is_a?(Array)
       raise ArgumentError, "The length of keys must be the same as param#len." unless keys.length == param.len
       keys.each do |key|
         raise ArgumentError, "key must be hex string." unless hex_string?(key)

lib/wots/public_key.rb

@@ -6,8 +6,8 @@ class Signature
     attr_reader :param, :sigs
 
     def initialize(param, sigs)
-      raise ArgumentError "param must be WOTS::Param." unless param.is_a?(WOTS::Param)
-      raise ArgumentError "sigs must be Array." unless sigs.is_a?(Array)
+      raise ArgumentError, "param must be WOTS::Param." unless param.is_a?(WOTS::Param)
+      raise ArgumentError, "sigs must be Array." unless sigs.is_a?(Array)
       raise ArgumentError, "The length of sigs must be the same as param#len." unless sigs.length == param.len
       sigs.each do |sig|
         raise ArgumentError, "sig must be hex string." unless hex_string?(sig)

lib/wots/signature.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 require 'spec_helper'
+require 'securerandom'
+require 'digest'
 
 RSpec.describe WOTS do
 
@@ -41,4 +43,22 @@
       end
     end
   end
+
+  describe 'All params' do
+    let(:params) { [ WOTS::Param::SHA256, WOTS::Param::SHA512, WOTS::Param::SHAKE256 ] }
+    it do
+      params.each do |param|
+        seed = SecureRandom.hex(param.n)
+        pub_seed = SecureRandom.hex(param.n)
+        message = SecureRandom.hex(param.n)
+
+        private_key = WOTS::PrivateKey.from_seed(param, seed)
+        public_key = WOTS::PublicKey.from_private_key(private_key, pub_seed)
+
+        signature = private_key.sign(pub_seed, message)
+        pubkey_from_sig = WOTS::PublicKey.from_signature(signature, pub_seed, message)
+        expect(pubkey_from_sig).to eq(public_key)
+      end
+    end
+  end
 end