Need help with implementing Vigenere cipher into TorqueScript
by Ryan Froese · in Torque Developer Network · 09/06/2011 (6:43 pm) · 1 replies
Hey, i'm trying to make a plaintext encryptor/cipher, but it isnt working out so well. The exact one im trying to make is a Vigenere cipher, which perfectly suits my needs. Here's my code so far, but right now, it just returns whatever you put in as the input, but I have no idea how to fix this:
function Vigenere(%input, %key, %forward)
{
%alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
%key = strUpr(%key);
%key_len = strLen(%key);
for (%i = 0; %i < %key_len; %i++)
{
%key_char = strpos(%alphabet, getSubStr(%key, %i, 1));
if (%key_char < 0)
continue;
%adjusted_key = %adjusted_key @ getSubStr(%alphabet, %key_char, 1);
}
%key = %adjusted_key;
%key_len = strLen(%key);
if (%key_len == 0)
{
echo("no key");
%key = "a";
%key_len = 1;
}
// Transform input:
%input_len = strLen(%input);
%output = "";
%key_index = 0;
%in_tag = false;
for (%i = 0; %i < %input_len; %i++)
{
%input_char = getSubStr(%input, %i, 1);
if(%input_char == "<")
%in_tag = true;
else if(%input_char == ">")
%in_tag = false;
if(%in_tag)
{
%output = %output @ %input_char;
continue;
}
%input_char_value = strpos(%alphabet, %input_char);
if (%input_char_value < 0)
{
%output = %output @ %input_char;
continue;
}
%lowercase = %input_char_value >= 26 ? true : false;
if (%forward)
%input_char_value += strpos(%alphabet, getSubStr(%key, %key_index, 1));
else
%input_char_value -= strpos(%alphabet, getSubStr(%key, %key_index, 1));
%input_char_value += 26;
if (%lowercase)
%input_char_value = %input_char_value % 26 + 26;
else
%input_char_value %= 26;
%output = %output @ getSubStr(%alphabet, %input_char_value, 1);
%key_index = (%key_index + 1) % key_len;
}
return %output;
}
About the author
Hi, I'm Ryan. I'm 14 years old and im a junior programmer in TorqueScript and C# on my free time. I currently have about as much knowledge of TorqueScript as the average university grad does about C.
Torque Owner Guy Allard
Default Studio Name
There are a couple of little errors in there that are stopping it working. Firstly,
needs to be changed to use the $= comparison operator instead of == as you are comparing strings and not numbers. So that becomes:
then, almost at the end of the function, you've left the % off the key_len variable name:
should be