From bfd398596afed66754011b6720e5891c4897c858 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=A9my=20Zurcher?= <jeremy@asynk.ch>
Date: Fri, 5 Aug 2011 23:38:26 +0200
Subject: update jcryption and specs

---
 lib/ayk/jcryption.rb   | 75 +++-----------------------------------------------
 spec/jcryption_spec.rb | 16 -----------
 2 files changed, 4 insertions(+), 87 deletions(-)

diff --git a/lib/ayk/jcryption.rb b/lib/ayk/jcryption.rb
index 6e4d1ed..3b4871f 100644
--- a/lib/ayk/jcryption.rb
+++ b/lib/ayk/jcryption.rb
@@ -1,14 +1,7 @@
 #! /usr/bin/env ruby
 # -*- coding: UTF-8 -*-
-
-#----------------------------------------------------------------------------
 #
-# File     : jcryption.rb
-# Author   : Jérémy Zurcher <jeremy@asynk.ch>
-# Date     : 11/09/09 
-# License  :
-#
-#   Copyright (c) 2009 Jérémy Zurcher
+#   Copyright (c) 2009-2011 Jérémy Zurcher
 #
 #   Permission is hereby granted, free of charge, to any person obtaining
 #   a copy of this software and associated documentation files (the
@@ -31,75 +24,15 @@
 #
 #----------------------------------------------------------------------------
 #
-def Math.power_modulo(b, p, m)
-    if p == 1
-        b % m
-    elsif (p & 0x1) == 0
-        t = power_modulo(b, p >> 1, m)
-        (t * t) % m
-    else
-        (b * power_modulo(b, p-1, m)) % m
-    end
-end
-#
-class Fixnum
-    def to_bytes
-        str = ''
-        int = self
-        while int!=0 do
-            int,r = int.divmod 256
-            str += r.chr
-        end
-        str
-    end
-end
-#
-class Bignum
-    #
-    class << self
-        def from_bytes bytes
-            val = 0
-            idx = 0
-            bytes.each_byte{ |b|
-                val += b << 8 * idx
-                idx += 1
-            }
-            val
-        end
-    end
-    #
-    def to_bytes
-        str = ''
-        bint = self
-        while bint!=0 do
-            bint,r = bint.divmod 256
-            str += r.chr
-        end
-        str
-    end
-    #
-    def bits
-        s = self.to_bytes
-        while s[-1].ord==0
-            s.slice!(-1)
-        end
-        bit_len = s.length * 8
-        tmp = s[-1].ord
-        while not tmp & 0x80
-            bit_len-=1
-            tmp <<=1
-        end
-        bit_len
-    end
-end
+require 'ayk/maths'
 #
 module JCryption
     #
     def decrypt data, d, n
-        s = data.split(' ').inject('') do |str,block| str += ( Math::power_modulo( block.to_i(16), d, n ) ).to_bytes end
+        s = data.split(' ').inject('') do |str,block| str += ( Math::prime_power_modulus( block.to_i(16), d, n ) ).to_bytes end
         sum,crc = 0,s.slice(0,2).to_i(16)
         s.slice(2..-1).each_char do |char| sum += char.ord end
-        return ( crc == sum & 0xFF ) ? s : nil 
+        return ( crc == sum & 0xFF ) ? s : nil
     end
     module_function :decrypt
     #
diff --git a/spec/jcryption_spec.rb b/spec/jcryption_spec.rb
index a974ea1..ce1d174 100644
--- a/spec/jcryption_spec.rb
+++ b/spec/jcryption_spec.rb
@@ -5,22 +5,6 @@ require 'ayk/jcryption'
 #
 describe JCryption do
     #
-    describe 'Bignum' do
-        it '#to_bytes #from_bytes should work' do
-            0x217962755220666f207463657073612074656577732061207369206d756e676942.should eql Bignum.from_bytes(0x217962755220666f207463657073612074656577732061207369206d756e676942.to_bytes)
-        end
-        it '#bits' do
-            K_BITS = 1024
-            k = JCryption.gen_keypair( K_BITS )
-            k.n.to_i.bits.should eql k.d.to_i.bits
-            k.d.to_i.bits.should eql k.d.to_i.bits
-            k.d.to_i.bits.should eql K_BITS
-            k.p.to_i.bits.should eql k.q.to_i.bits
-            k.q.to_i.bits.should eql k.q.to_i.bits
-            k.q.to_i.bits.should eql K_BITS/2
-        end
-    end
-    #
     describe 'JCryption' do
         it 'should decrypt data' do
             data = '50c412c556a9fab55b50bd0d989067b341f9cdbf12ccb65aeb69dbb360a8e0dbd2069d686873b659b1be7a4c78fe631d362dbf538a5298ecaff19f78cd859897a7317c71b51b90e0a8c03e10059b68826bfeb194a4339a0ecc4a571ba9066fcf3504ffe76e07468cbe03337d3cfebd4efe687f5da72bf694dada987cea884180 ac07cc8462ce0f3e23dafe5d19f47eb33024c91de48413a971bf3b88c159090a26933f694d868bad61517a817f57998ed57bcebcd46a4ed8661cec3e24a8cdf21595902c2fd566820382e2d4f2ee7f1f11fa87a760bcecdf46282147d2c3a1afed3797d22296abcc3b1289489e7c265b3b4223bf93cbf0bb5122c021501a4305'
-- 
cgit v1.1-2-g2b99