public string ceaserShiftTable(string lines) //Method for displaying the ceaser cipther table.
{
DateTime begin = DateTime.UtcNow; //Start of timer.
string saveFile = " "; //Defines saveFile string.
int maxLength = 15; //Defines the max length of the first line.
string textInput = lines.Substring(0, Math.Min(lines.Length, maxLength)); //Defines the textInput as the maxLength of the input string so that only the first line is displayed in the table.
encryptDecrypt c = new encryptDecrypt(); //Makes an instance of the encryptDecrypt class.
Console.WriteLine("\nDecryption shift (left)\t\tCandidate plaintext:\n"); //Table header
for (int count = 1; count <= 26; count++) //Loops through each letter in the "letterArray" array
{
Console.WriteLine("\t" + count + "\t\t\t" + c.letterShift(textInput, count));
}
int shiftKey = 0;
while (shiftKey >= 0)
{ //Start of While loop.
Console.WriteLine("\nPlease enter the correct key shift or press q to quit."); //Gets the user to enter the correct key shift.
string temp = Console.ReadLine();
if (temp == "q")
{
break; //breaks out of the while loop if q is entered.
}
int.TryParse(temp, out shiftKey);
if (shiftKey >= 1 && shiftKey <= 26)
//Checks to see if a correct key shift option has been choosen.
{
Console.WriteLine("\nShift Key = {0}", shiftKey); //Displays user's choosen key shift.
string output = lines;
output = output.Replace(" ", string.Empty); //Removes all the spaces out of the string.
output = output.Replace("\n", string.Empty); //Removes all the new lines out the string.
output = output.Replace("\r", string.Empty); //Removes al the carridge returns out of the string
saveFile = c.letterShift(output, shiftKey); //Calls the letterShift and parses the message with the keyshift to be decryoted.
break;//Breaks out of the loop when a valid entry has been entered.
}
else
//Displays this message if any input outside of 1-26 is entered.
{
Console.WriteLine("Sorry that entry wasn't a valid Shift Key option.");
}
}//End of While loop.
DateTime end = DateTime.UtcNow; //End of timer
Console.WriteLine("\nMeasured time taken to decrpyt the message using shift key: " + (end - begin).TotalMilliseconds + " ms."); //Outputs the time taken to decrypt
return(saveFile);
}
}//End of letterShift method.
public string frequencyAnalysis(string message)
{
DateTime begin = DateTime.UtcNow;//Start of timer.
//Start of code for finding the most common letter.
int commonCharNumber = 0;
char commonChar = ' ';
foreach (char findChar in message)
{//Start of code to find the most commonn letter.
int charCount = 0;
foreach (char matchingChars in message)
{
if (findChar == matchingChars)
{
charCount++;
}
}
if (commonCharNumber < charCount)
{
commonChar = findChar;
commonCharNumber = charCount;
}
}//End of code to find the most common letter.
Console.WriteLine("\n\nMost occuring letter = " + commonChar + "/" + ((char)commonChar - 0) + "\n\n");//Displays the most occuring letter and its char value
int keyShift = (69 - (char)(commonChar));//Key shift negative value is calculated by taking the char value of E (69) then minusing the most occurring Char
Console.WriteLine("Key shift = +" + (26 + keyShift) + " or " + keyShift + "\n\n");//Displays the positive value key shift and the negative value of the key shift.
encryptDecrypt c = new encryptDecrypt();//Makes an instance of the encryptDecrypt class.
string newMessage = c.letterShift(message, keyShift);//Calls the letterShift method and parses the encrypted message plus the keyShift.
Console.WriteLine(userInterface.yellowLine(newMessage));//Displays the Decrypted message.
Console.ForegroundColor = ConsoleColor.Green;
DateTime end = DateTime.UtcNow; //End of timer
Console.WriteLine("Measured time taken to decrpyt the message using shift key: " + (end - begin).TotalMilliseconds + " ms."); //Outputs the time taken to decrypt
return(message);
}
static void Main(string[] args)//Main method contains the user interface.
{
int mainMenu = 1;
while (mainMenu <= 1)
{
Console.Clear();
Console.ForegroundColor = ConsoleColor.Green;
string gretting = "Morning";
int firstChoice = 0;
int secondChoice = 0;
int thirdChoice = 0;
int forthChoice = 0;
int fifthChoice = 0;
if (DateTime.Now.ToString("tt") == "PM")//Checks to see if it is the afternoon or not.
{
gretting = "Afternoon";
}
while (firstChoice >= 0)
{
try
{
Console.ForegroundColor = ConsoleColor.White;
Console.WriteLine("\n*****MAIN MENU*******");
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("\nGood {0}, please choose an option:(or press q to quit the program.) \n1. Decrypt a message. \n2. Encrypt a message.", gretting);///Gets the user to enter an option.
string temp = Console.ReadLine();
if (temp == "q")
{
mainMenu = 2;
break;
}
int.TryParse(temp, out firstChoice);
if (firstChoice >= 1 && firstChoice <= 2) //Checks if a valid option has been entered (1/2)
{
break; //Breaks out of while loop if conditions are met.
}
else
{
throw new FormatException();
}
}//End of try statement.
catch (FormatException)//Catches the errors.
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("\nSorry that wasn't a valid option.");//Displays a red warning if an invalid entry is made.
Console.ResetColor();
Console.ForegroundColor = ConsoleColor.Green;
} //End of catch statement.
} //End of while loop.
switch (firstChoice) //Encrypt or Decrypt option.
{
case 1: //Decrypt a message option.
while (secondChoice >= 0)
{
try
{
Console.WriteLine("Please choose an option to Decrypt your message (or type 'm' to go back to the main menu) :\n1. Ceaser Cipher Table. \n2. Frequency Analysis.");
string temp = Console.ReadLine();
if (temp == "m")
{
break;
}
int.TryParse(temp, out secondChoice);
if (secondChoice >= 1 && secondChoice <= 2)
{
break;
}
else
{
throw new FormatException();
}
}
catch (FormatException)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.Beep();
Console.WriteLine("\nSorry that wasn't a valid option.");
Console.ResetColor();
Console.ForegroundColor = ConsoleColor.Green;
}
}
break; //Break of case 1
case 2: //Encrypt a message option.
while (thirdChoice >= 0)
{
try
{
Console.WriteLine("Please choose an option:(or type 'm' to go back to the main menu) \n1. Encrypt your own message \n2. The message in a .txt file");
string temp = Console.ReadLine();
if (temp == "m")
{
break;
}
int.TryParse(temp, out thirdChoice);
if (thirdChoice >= 1 && thirdChoice <= 2)
{
break;
}
else
{
throw new FormatException();
}
}
catch (FormatException)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("\nSorry that wasn't a valid option.");
Console.ResetColor();
Console.ForegroundColor = ConsoleColor.Green;
}
} //End of while loop.
break; //Break for end of case 2
}//End of switch statement.
switch (secondChoice) //Decrypt using Caeser cipher table/ frequency analysis.
{
case 1: //Decrypt using the Caeser cipher table option.
while (forthChoice >= 0)
{
try
{
Console.WriteLine("Please choose what you would like to Decrypt using the Caeser Cipher Table:(or type 'm' to go back to the main menu) \n1. The caesarShiftEncoded.txt file \n2. Your own message.");
string temp = Console.ReadLine();
if (temp == "m")
{
break;
}
int.TryParse(temp, out forthChoice);
if (forthChoice >= 1 && forthChoice <= 2)
{
break;
}
else
{
throw new FormatException();
}
}
catch (FormatException)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("\nSorry that wasn't a valid option.");
Console.ResetColor();
Console.ForegroundColor = ConsoleColor.Green;
}
} //End of while loop.
break; //Break for end of case 1
case 2: //Decrypt using the Ceaser Cipher frequency analysis option.
while (fifthChoice >= 0)
{
try
{
Console.WriteLine("Please choose what you would like to preform frequency analysis on:(or type 'm' to go back to the main menu) \n1. The caesarShiftEncoded.txt file \n2. Your own message.");
string temp = Console.ReadLine();
if (temp == "m")
{
break;
}
int.TryParse(temp, out fifthChoice);
if (fifthChoice >= 1 && fifthChoice <= 2)
{
break;
}
else
{
throw new FormatException();
}
}
catch (FormatException)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("\nSorry that wasn't a valid option.");
Console.ResetColor();
Console.ForegroundColor = ConsoleColor.Green;
}
} //End of while loop.
break; //Break that ends case 2
}
switch (thirdChoice) //Encrypt own message or .txt file.
{
case 1: //Own message option.
{
encryptDecrypt c = new encryptDecrypt(); //Makes an instance of the encryptDecrypt class.
Console.WriteLine("Please enter the message you would like to encrypt with the Caeser cipher encoding."); //Gets the user to enter their message for encryption.
string messageToEncrypt = Console.ReadLine(); //Gets the users message
string messageToEncryptUpper = messageToEncrypt.ToUpper(); //Converts the message to all upper case.
messageToEncryptUpper = messageToEncryptUpper.Replace(" ", string.Empty); //Removes all the spaces out of the string.
Console.WriteLine("Please enter the key shift you want to apply to your message."); //Gets the user to enter a key shift to apply to their message.
int keyShift = int.Parse(Console.ReadLine()); //Gets the key shift value.
string saveFile = c.letterShift(messageToEncryptUpper, keyShift); //Calls the letterShift method and parses the user's message with their intended keyShift.
Console.WriteLine("Your now encrypted message with a keyshift of " + keyShift + " applied:"); //Displays a message with the useres inputed keyshift value.
Console.WriteLine("\n" + yellowLine(saveFile)); //Displays the new encrypted message with a differnt colour.
Console.ForegroundColor = ConsoleColor.Green; //Changes the console colour back to green.
Console.WriteLine("Press any key to return to main menu");
Console.ReadLine();
} //End of case 1
break; //break of switch case 1.
case 2: //.txt file option.TODO
{
int start = 0;
//string newPath = "";
Console.WriteLine("Please enter the full file name you want to load to apply a ceaser cipher encoding to.");
string newPath = Console.ReadLine();
while (start >= 0)
{
try
{
Console.WriteLine("\nLoading....");
string lines = File.ReadAllText(newPath);
Console.WriteLine("Load succseful!");
encryptDecrypt c = new encryptDecrypt();
string messageToEncryptUpper = lines.ToUpper(); //Converts the message to all upper case.
messageToEncryptUpper = messageToEncryptUpper.Replace(" ", string.Empty); //Removes all the spaces out of the string.
Console.WriteLine("Please enter the key shift you want to apply to your message."); //Gets the user to enter a key shift to apply to their message.
int keyShift = int.Parse(Console.ReadLine()); //Gets the key shift value.
string saveFile = c.letterShift(messageToEncryptUpper, keyShift); //Calls the letterShift method and parses the user's message with their intended keyShift.
Console.WriteLine("\nYour now encrypted message with a keyshift of " + keyShift + " applied:"); //Displays a message with the useres inputed keyshift value.
Console.WriteLine("\n" + yellowLine(saveFile)); //Displays the new encrypted message with a differnt colour.
Console.ForegroundColor = ConsoleColor.Green; //Changes the console colour back to green.
Console.WriteLine("Presss any key to return to main menu");
Console.ReadLine();
break;
}
catch
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("\nSorry file could not be Loaded!");
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("\nPlease enter a new path to load from or press m to go to main menu.\n\n"); //Gets the user to enter a new location for the save.
newPath = Console.ReadLine(); //Gets the user's new file location to save to.
if (newPath == "m") //option to quit to main menu.
{
break;
}
} //End of catch
} //End of while
} //End of case 1
break;
}//End of switch thirdChoice
switch (forthChoice)
{
case 1:
//Descrypts using caeser cipher table on "caeserShiftEncodedText.txt" file
string lines = "";
try
{
lines = File.ReadAllText(@"\\srv124\students$\309219\my documents\visual studio 2010\Projects\ConsoleApplication126\ConsoleApplication126\TextFile1.txt");
//@"z:\\C# programs\\Assessment 1\\caesarShiftEncodedText.txt");//Reads in the encrypted message.
}
catch //(FileNotFoundException)
{
Console.WriteLine("Sorry file could not be found");
break;
}
encryptDecrypt c = new encryptDecrypt(); //Makes an instance of the encryptDecrypt class.
Console.WriteLine("\nThe decrypted message:");
string saveFile = c.ceaserShiftTable(lines); //Defines saveFile as the return of the caeaserShiftTable method
Console.WriteLine("\nYour decoded message:\n");
Console.WriteLine(yellowLine(saveFile)); //Displays the decrypted message.
Console.ForegroundColor = ConsoleColor.Green; //Changes the console foreground colour back to green.
string newPath = "z:\\C# programs\\Assessment 1\\HaydensCaesarShiftDecodedText.txt";
int start = 0;
while (start >= 0) //while loop to repeat codeonce a new location has been entered.
{
try
{
File.WriteAllText(newPath, saveFile); //Saves decrypted message to a .txt file.
Console.WriteLine("\n**Decrypted message file saved!**");
Console.WriteLine("\nPress any key to return to main menu.");
Console.ReadLine();
break;
}
catch //If the file to save to can't be found the error is caught.
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("\nSorry file could not be Saved!");
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("\nPlease enter a new path to save to or press m to go to main menu.\n\n"); //Gets the user to enter a new location for the save.
newPath = Console.ReadLine(); //Gets the user's new file location to save to.
if (newPath == "m") //option to quit to main menu.
{
break;
}
}
}
break; //Break for case 1.
case 2:
//Decrypts using caeser cipher table on own message option.
Console.WriteLine("Please enter your message."); //Gets the user to enter their message to be decrypted.
string lower = Console.ReadLine(); //Gets the user's encrypted message.
string myLines = lower.ToUpper(); //Changes all inputed text to uppercase.
encryptDecrypt b = new encryptDecrypt(); //Makes an instance of the encrypDecrypt class.
string newSaveFile = b.ceaserShiftTable(myLines); //Calls the caeserShiftTable method parses the message then defines the newSaveFile as the return.
Console.WriteLine("\nYour decoded message:\n");
Console.WriteLine(yellowLine(newSaveFile)); //Calls the different colour method.
Console.ForegroundColor = ConsoleColor.Green; //Changes the console colour back to green.
break;
}
switch (fifthChoice)
{
case 1: //Calls frequency analysis on caserShiftEncoded.txt
Console.WriteLine("Encrypted message:\n\n");
string lowerCase = System.IO.File.ReadAllText(@"z:\\C# programs\\Assessment 1\\caesarShiftEncodedText.txt");
string lines = lowerCase.ToUpper();
Console.WriteLine(lines); //Displays the encrypted message.
lines = lines.Replace(" ", string.Empty); //Removes all the spaces out of the string.
lines = lines.Replace("\r", string.Empty); //Removes all the carridge returns out of the string
lines = lines.Replace("\n", string.Empty); //Removes all the new lines out of the string
encryptDecrypt b = new encryptDecrypt(); //Makes an instance of the encryptDecrypt class.
b.frequencyAnalysis(lines);
break;
case 2: //Calls frequency analysis for own message.
Console.WriteLine("Please enter your message to preform a caeser shift frequency analysis on.");
string ownMessage = Console.ReadLine();
string ownMessageUpper = ownMessage.ToUpper();
ownMessageUpper = ownMessageUpper.Replace(" ", string.Empty);
encryptDecrypt c = new encryptDecrypt();
c.frequencyAnalysis(ownMessageUpper);
break;
}
} //End of switch statement.
} //End of mainMenu while loop.
