From 884dfb99ac2a8a77a89027e0559e4f3d140b190a Mon Sep 17 00:00:00 2001
From: Matthew Ellison <m_ellison@ymail.com>
Date: Thu, 3 May 2018 11:37:59 -0400
Subject: [PATCH] Added new Autokey class for Autokey cipher

---
 Headers/Autokey.hpp     | 27 ++++++++++++
 SourceFiles/Autokey.cpp | 98 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 125 insertions(+)
 create mode 100644 Headers/Autokey.hpp
 create mode 100644 SourceFiles/Autokey.cpp

diff --git a/Headers/Autokey.hpp b/Headers/Autokey.hpp
new file mode 100644
index 0000000..04a9012
--- /dev/null
+++ b/Headers/Autokey.hpp
@@ -0,0 +1,27 @@
+//Ciphers/Headers/Autokey.hpp
+//Matthew Ellison
+// Created: 5-2-18
+//Modified: 5-3-18
+//This file contains the declaration of the Autokey class
+//This class will encode a message using the Autokey cipher
+
+#ifndef AUTOKEY_HPP
+#define AUTOKEY_HPP
+
+#include "Vigenere.hpp"
+
+
+class Autokey : public Vigenere{
+protected:
+	virtual void encodeSetKeyword(std::string& key, std::string input);
+	virtual void decodeSetKeyword(std::string& key, std::string input);
+	std::string decode();
+public:
+	Autokey();
+	~Autokey();
+	virtual std::string encode(std::string key, std::string input);
+	virtual std::string decode(std::string key, std::string input);
+};
+
+
+#endif //AUTOKEY_HPP
diff --git a/SourceFiles/Autokey.cpp b/SourceFiles/Autokey.cpp
new file mode 100644
index 0000000..093338b
--- /dev/null
+++ b/SourceFiles/Autokey.cpp
@@ -0,0 +1,98 @@
+//Ciphers/SourceFiles/Autokey.cpp
+//Matthew Ellison
+// Created: 5-3-18
+//Modified: 5-3-18
+//This file contains the implementation of the Autokey class
+
+
+#include "../Headers/Autokey.hpp"
+#include <string>
+
+
+void Autokey::encodeSetKeyword(std::string& key, std::string input){
+	//Remove all unneccessary elements from the key
+	Vigenere::setKeyword(key);
+	key = Vigenere::getKeyword();
+	//Remove all unneccessary elements from the input
+	Vigenere::setInputString(input);
+	input = getInputString();
+	key.append(input);
+
+	//This will take a long time if the keyword in long
+	//Remove the last letter in the string until it is the same size as the input
+	while(key.size() > input.size()){
+		key.erase(key.end() - 1);
+	}
+
+	//Set the new Keyword
+	keyword = key;
+	//Make sure to update the offset
+	setOffset();
+}
+
+void Autokey::decodeSetKeyword(std::string& key, std::string input){
+	//Remove all unneccessary elements from the key
+	Vigenere::setKeyword(key);
+	key = Vigenere::getKeyword();
+	//Remove all unneccessary elements from the input
+	Vigenere::setInputString(input);
+}
+
+std::string Autokey::decode(){
+	//This is going to take a long time no matter what
+	//You must decode what you can and then add the decoded portion to the key and do it all over again
+	//std::string input;
+	std::string output;
+	std::string key = keyword;
+	unsigned int keyLength = keyword.size();
+	for(int cnt = 0;(key.size() * cnt) < inputString.size();++cnt){
+		//Make sure you are not going to run out of bounds with the keyword
+		//This also allows the key to be longer than the message
+		if(keyword.size() == keyLength){
+			while(keyLength > inputString.size()){
+				keyword.erase(keyword.end() - 1);
+			}
+		}
+		else if(keyword.size() > inputString.size()){
+			while(keyword.size() > inputString.size()){
+				keyword.erase(keyword.end() - 1);
+			}
+		}
+		else{
+			while((keyword.size() + keyLength) > inputString.size()){
+				//key.erase(key.end() - 1);
+				--keyLength;
+			}
+		}
+
+		//Decode the portion that you have
+		Vigenere::decode();
+		std::string temp = outputString.substr(cnt * key.size(), keyLength);
+		output += temp;
+		keyword += temp;
+		//Make sure to update the offsets
+		setOffset();
+	}
+
+	return outputString;
+}
+
+Autokey::Autokey(){
+	reset();
+}
+
+Autokey::~Autokey(){
+}
+
+std::string Autokey::encode(std::string key, std::string input){
+	reset();;
+	encodeSetKeyword(key, input);
+	return Vigenere::encode();
+}
+
+std::string Autokey::decode(std::string key, std::string input){
+	reset();
+	setInputString(input);
+	decodeSetKeyword(key, input);	//Decoding is a bit different because part of the key is also part of the original message
+	return Autokey::decode();
+}