Easy ROT39 Encryption / Decryption Class

Recently a user inquired about ROT39 encryption ( a variation of the ROT13 method). This is a simple implementation that is very easy to use. Just copy the code below into an empty class file and compile.

using System;
namespace PAB.Utils
{
public class ROT39
{
private const long LOWER_LIMIT = 48; //ascii for 0
private const long UPPER_LIMIT = 125; //ascii for {
private const long CHARMAP = 39;
public static string DoROT39(string sData)
{
string tempROT39 = null;
try
{
// ROT39 (a variation of the ROT13 function)
string sReturn = null;
long nCode = 0;
long nData = 0;
//initialize the byte array to the size of the string passed.
byte[] bData =new byte[sData.Length];
//reverse the string
char[] tmpsData=sData.ToCharArray();
Array.Reverse(tmpsData);
sData="";
foreach(char c in tmpsData)
sData+=c.ToString();
//cast string into the byte array
bData = System.Text.Encoding.UTF8.GetBytes(sData);
long tempFor1 = bData.GetUpperBound(0);
for (nData = 0; nData <= tempFor1; nData++)
{
//with the ASCII value of the character
nCode = bData[nData];
//assure the ASCII value is between
//the lower and upper limits
if ((nCode >= LOWER_LIMIT) & (nCode <= UPPER_LIMIT))
{
//shift the ASCII value by the CHARMAP const value
nCode = nCode + CHARMAP;
//perform a check against the upper
//limit. If the new value exceeds the
//upper limit, rotate the value to offset
//from the beginning of the character set.
if (nCode > UPPER_LIMIT)
{
nCode = nCode - UPPER_LIMIT + LOWER_LIMIT - 1;
}
}
//reassign the new shifted value to
//the current byte
bData[nData] = (byte)nCode;
}
//convert the byte array back
//to a string and exit
sReturn = System.Text.Encoding.UTF8.GetString(bData);
//assign the return string
tempROT39 = sReturn;
}

catch
{
}
return tempROT39;
}
} // end class ROT39

class Tester
{
static void Main(string[] args)
{
string s = "the quick brown fox jumped over the bouncing blue geek";
s=ROT39.DoROT39(s);
Console.WriteLine(s);
s=ROT39.DoROT39(s);
Console.WriteLine(s);
Console.ReadLine();
}
}
} // end namespace


Submission Date:  3/29/2006 11:16:59 AM
Submitted By:  Peter Bromberg
My Home Page:  http://www.eggheadcafe.com