master: add support for brute forcing caesar

EXAMPLE

@@ -8,6 +8,36 @@ MVV
 > toycipher -d caesar -k G mvv 
 FOO
 
+* Brute forcing caesar:
+
+> toycipher -d caesar -b foobar
+ENNAZQ
+DMMZYP
+CLLYXO
+BKKXWN
+AJJWVM
+ZIIVUL
+YHHUTK
+XGGTSJ
+WFFSRI
+VEERQH
+UDDQPG
+TCCPOF
+SBBONE
+RAANMD
+QZZMLC
+PYYLKB
+OXXKJA
+NWWJIZ
+MVVIHY
+LUUHGX
+KTTGFW
+JSSFEV
+IRREDU
+HQQDCT
+GPPCBS
+FOOBAR
+
 == Multiple keys ==
 
 > toycipher -e caesar -k G,M,A,R,K "The moose is loose"

ROADMAP

@@ -22,6 +22,12 @@
 -==-
 * Rudimentary frequency analysis 
 * Caesar brute force guessing
+* LICENSE
+* Support supplying a key file 
+
+1.0
+
+* Large text testing
 
 1.1 
 

lib/toycipher/caesar.rb

@@ -15,12 +15,8 @@ def initialize
       @offset = 0
     end
 
-    # TODO
-    def brute
-      (0..25).each do |i|
-        (@guess ||= []) << decrypt(ciphertext, i)
-      end
-      @guess
+    def brute(ciphertext = @ciphertext)
+      @alph.inject([]) { |acc, ch| acc << decrypt(ciphertext, ch) }
     end
 
     def encrypt(plaintext = @plaintext, offset = @offset)

script/toycipher

@@ -51,6 +51,9 @@ class OptParseToyCipher
         opts.on("-t", "--transpose", "Transpose m x n lines of text to be n x m") do
           options[:transpose] = true
         end
+        opts.on("-b", "--brute", "Brute force if possible (Caesar)") do
+          options[:brute] = true
+        end
         opts.on("-v", "--verbose", "Verbose setting") { options[:verbose] = true }
         opts.on("-V", "--version", "Show version info") { puts "#{ToyCipher::VERSION_STR}"; exit 0; }
       end
@@ -157,6 +160,11 @@ end
 
 print_result(@results) if @results
 
+if @options[:cipher]
+  #puts "Setting cipher to #{@options[:cipher]}"
+  @cipher = instance_eval "ToyCipher::#{@options[:cipher]}.new" # shouldn't have to do this per key
+end
+
 @cipher ||= ToyCipher::ToyCipherBase.new
 
 if @options[:analysis] 
@@ -171,4 +179,9 @@ if @options[:analysis]
   end
 end
 
+if @options[:brute]
+  puts "Trying to brute force #{@options[:ciphertext]}" if @options[:verbose]
+  puts @cipher.brute @options[:ciphertext]
+end
+
 

test/tc_caesar.rb

@@ -31,5 +31,38 @@ def test_decrypt
     assert_equal @plaintext, @cipher.decrypt(@ciphertext, @offset)
   end
 
+  def test_brute
+    ans = <<-ANS
+CDECDE
+BCDBCD
+ABCABC
+ZABZAB
+YZAYZA
+XYZXYZ
+WXYWXY
+VWXVWX
+UVWUVW
+TUVTUV
+STUSTU
+RSTRST
+QRSQRS
+PQRPQR
+OPQOPQ
+NOPNOP
+MNOMNO
+LMNLMN
+KLMKLM
+JKLJKL
+IJKIJK
+HIJHIJ
+GHIGHI
+FGHFGH
+EFGEFG
+DEFDEF
+ANS
+    try = @cipher.brute(@ciphertext)
+    assert_equal ans.gsub(/\n/, ''), @cipher.brute(@ciphertext).to_s
+  end
+
 end
 

test/tc_cli.rb

@@ -164,6 +164,41 @@ def test_analysis
 Y: ###########                         (11)
 Z: #####################               (21)
 28,14,5,17,20,20,34,10,7,11,20,17,21,5,12,21,9,25,20,9,15,9,12,7,11,21
+ANS
+    assert_equal ans, cli_out
+  end
+
+  def test_brute_caesar 
+    args = "-d caesar -b 'FOOBAR'"
+    cli_out = %x[#{@cli} #{args}]
+    puts cli_out if verbose?
+    ans = <<-ANS
+ENNAZQ
+DMMZYP
+CLLYXO
+BKKXWN
+AJJWVM
+ZIIVUL
+YHHUTK
+XGGTSJ
+WFFSRI
+VEERQH
+UDDQPG
+TCCPOF
+SBBONE
+RAANMD
+QZZMLC
+PYYLKB
+OXXKJA
+NWWJIZ
+MVVIHY
+LUUHGX
+KTTGFW
+JSSFEV
+IRREDU
+HQQDCT
+GPPCBS
+FOOBAR
 ANS
     assert_equal ans, cli_out
   end