Background: I'm trying to convert Mike Shaffer's VB RC4 encryption to C# (https://web.archive.org/web/20210927195845/https://www.4guysfromrolla.com/articles/091802-1.3.aspx). See a previous question of mine at Converting Mike Shaffer's RC4Encryption to C#.
It seems my encryption is not working.
Using the demo page at: https://web.archive.org/web/20000303125329/http://www.4guysfromrolla.com:80/demos/rc4test.asp, with password of "abc":
Plain text: og;|Q{Fe should result in
A2 FA E2 55 09 A4 AB 16
However, my code is generating the 5th char as 9, instead of 09:
A2 FA E2 55 9 A4 AB 16
Another example - Plain text: cl**z!Ss should result in
AE F1 F3 03 22 FE BE 00
However, my code is generating:
AE F1 F3 3 22 FE BE 0
It seems it's only a problem with certain non-alphanumeric characters.
Here's my code:
private static string EnDeCrypt(string text) { int i = 0; int j = 0; string cipher = ""; // Call our method to initialize the arrays used here. RC4Initialize(password); // Set up a for loop. Again, we use the Length property // of our String instead of the Len() function for (int a = 1; a <= text.Length; a++) { // Initialize an integer variable we will use in this loop int itmp = 0; // Like the RC4Initialize method, we need to use the % // in place of Mod i = (i + 1) % 256; j = (j + sbox[i]) % 256; itmp = sbox[i]; sbox[i] = sbox[j]; sbox[j] = itmp; int k = sbox[(sbox[i] + sbox[j]) % 256]; // Again, since the return type of String.Substring is a // string, we need to convert it to a char using // String.ToCharArray() and specifying that we want the // first value, [0]. char ctmp = text.Substring(a - 1, 1).ToCharArray() [0]; itmp = ctmp; //there's an implicit conversion for char to int int cipherby = itmp ^ k; cipher += (char)cipherby; //just cast cipherby to a char } // Return the value of cipher as the return value of our // method return cipher; } public static string ConvertAsciiToHex(string input) { return string.Join(string.Empty, input.Select(c => Convert.ToInt32(c).ToString("X")).ToArray()); } public static string Encrypt(string text) { return ConvertAsciiToHex(EnDeCrypt(text)); } Here's how I get my encrypted result:
var encryptedResult = RC4Encrypt.Encrypt(valuetoencrypt);
