add all the specs

lib/metasploit/framework/jtr/cracker.rb

@@ -102,7 +102,7 @@ module Metasploit
           cmd_string = binary_path
           raise JohnNotFoundError, 'No suitable John binary was found on the system' if cmd_string.blank?
 
-          cmd = [ cmd_string,  '--session=' + john_session_id, '--nolog' ]
+          cmd = [ cmd_string,  '--session=' + john_session_id, '--nolog', '--dupe-suppression' ]
 
           if config.present?
             cmd << ( "--config=" + config )
@@ -148,6 +148,36 @@ module Metasploit
           @session_id ||= ::Rex::Text.rand_text_alphanumeric(8)
         end
 
+        # This method builds the command to show the cracked passwords.
+        #
+        # @raise [JohnNotFoundError] if a suitable John binary was never found
+        # @return [Array] An array set up for {::IO.popen} to use
+        def show_command
+          cmd_string = binary_path
+          raise JohnNotFoundError, 'No suitable John binary was found on the system' if cmd_string.blank?
+
+          pot_file = pot || john_pot_file
+          cmd = [cmd_string, "--show", "--pot=#{pot_file}", "--format=#{format}" ]
+
+          if config
+            cmd << "--config=#{config}"
+          end
+
+          cmd << hash_path
+        end
+
+        # This runs the show command in john to show cracked passwords.
+        #
+        # @yield [String] the output lines from the command
+        # @return [void]
+        def show_passwords
+          ::IO.popen(show_command, "rb") do |fd|
+            fd.each_line do |line|
+              yield line
+            end
+          end
+        end
+
         private
 
         # This method tries to identify the correct version of the pre-shipped

spec/lib/metasploit/framework/jtr/cracker_spec.rb

@@ -116,4 +116,38 @@ describe Metasploit::Framework::JtR::Cracker do
     end
 
   end
+
+  describe '#show_command' do
+    before(:each) do
+      expect(cracker).to receive(:binary_path).and_return john_path
+    end
+
+    it 'starts with the john binary path' do
+      expect(cracker.show_command[0]).to eq john_path
+    end
+
+    it 'has the --show flag' do
+      expect(cracker.show_command).to include '--show'
+    end
+
+    it 'uses the user supplied john.pot if there is one' do
+      cracker.pot = pot
+      expect(cracker.show_command).to include "--pot=#{pot}"
+    end
+
+    it 'uses default john.pot if the user did not supply one' do
+      expect(cracker).to receive(:john_pot_file).and_return other_pot
+      expect(cracker.show_command).to include "--pot=#{other_pot}"
+    end
+
+    it 'uses the user supplied format directive' do
+      cracker.format = nt_format
+      expect(cracker.show_command).to include "--format=#{nt_format}"
+    end
+
+    it 'puts the path to the has file at the end' do
+      cracker.hash_path = hash_path
+      expect(cracker.show_command.last).to eq hash_path
+    end
+  end
 end