Hey,
can someone help me with my XTEA Code?
Error:
can someone help me with my XTEA Code?
Code
Public Class XTea
Private Shared f_key As UInteger()
Public Sub New(ByVal password As String)
MsgBox(password)
f_key = FormatKey(password)
End Sub
Public Function Encrypt(ByVal input As String) As String
If input.Length = 0 Then
Throw New ArgumentException("Invalid input length!")
End If
If input.Length Mod 2 <> 0 Then
input += ControlChars.NullChar
End If
Dim dataBytes As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(input)
Dim cipher As String = String.Empty
Dim tempData As UInteger() = New UInteger(1) {}
For i As Integer = 0 To dataBytes.Length - 1 Step 2
tempData(0) = dataBytes(i)
tempData(1) = dataBytes(i + 1)
code(tempData, f_key)
cipher += ConvertUIntToString(tempData(0)) + ConvertUIntToString(tempData(1))
Next
Return cipher
End Function
Public Function Decrypt(ByVal Data As String) As String
Dim x As Integer = 0
Dim tempData As UInteger() = New UInteger(1) {}
Dim dataBytes As Byte() = New Byte((Data.Length \ 8) * 2 - 1) {}
For i As Integer = 0 To Data.Length - 1 Step 8
tempData(0) = ConvertStringToUInt(Data.Substring(i, 4))
tempData(1) = ConvertStringToUInt(Data.Substring(i + 4, 4))
decode(tempData, f_key)
dataBytes(x) = CByte(tempData(0))
x += 1
dataBytes(x) = CByte(tempData(1))
x += 1
Next
Dim decipheredString As String = System.Text.ASCIIEncoding.ASCII.GetString(dataBytes, 0, dataBytes.Length)
If decipheredString(decipheredString.Length - 1) = ControlChars.NullChar Then
decipheredString = decipheredString.Substring(0, decipheredString.Length - 1)
End If
Return decipheredString
End Function
Private Shared Function FormatKey(ByVal Key As String) As UInteger()
If Key.Length <= 5 Then
Throw New ArgumentException("Key must be between 6 and 16 characters in length")
End If
Key = Key.PadRight(16, " "c).Substring(0, 16)
Dim formattedKey As UInteger() = New UInteger(4) {}
Dim j As Integer = 0
For i As Integer = 0 To Key.Length - 1 Step 4
formattedKey(j) = ConvertStringToUInt(Key.Substring(i, 4))
j += 1
Next
Return formattedKey
End Function
Private Shared Sub code(ByVal v As UInteger(), ByVal k As UInteger())
Dim y As UInteger = v(0)
Dim z As UInteger = v(1)
Dim sum As UInt64 = 0
Dim delta As UInteger = &H9E3779B9UI
For i = 0 To 31
y += (z << 4 Xor z >> 5) + z Xor sum + k(sum And 3)
sum += delta
[color=#FF0000]z += (y << 4 Xor y >> 5) + y Xor sum + k(sum >> 11 And 3)[/color]
Next
v(0) = y
v(1) = z
End Sub
Private Shared Sub decode(ByVal v As UInteger(), ByVal k As UInteger())
Dim y As UInteger = v(0)
Dim z As UInteger = v(1)
Dim sum As UInteger = &HC6EF3720UI
Dim delta As UInteger = &H9E3779B9UI
For i = 0 To 31
[color=#FF0000]z -= (y << 4 Xor y >> 5) + y Xor sum + k(sum >> 11 And 3)[/color]
sum -= delta
y -= (z << 4 Xor z >> 5) + z Xor sum + k(sum And 3)
Next
v(0) = y
v(1) = z
End Sub
Private Shared Function ConvertStringToUInt(ByVal Input As String) As System.UInt32
Dim output As UInt32
output = Convert.ToUInt32(Input(0))
output += (Convert.ToUInt32(Input(1)) << 8)
output += (Convert.ToUInt32(Input(2)) << 16)
output += (Convert.ToUInt32(Input(3)) << 24)
Return output
End Function
Private Shared Function ConvertUIntToString(ByVal Input As System.UInt32) As String
Dim output As New System.Text.StringBuilder()
output.Append(Convert.ToChar(Input And &HFF))
output.Append(Convert.ToChar((Input >> 8) And &HFF))
output.Append(Convert.ToChar((Input >> 16) And &HFF))
output.Append(Convert.ToChar((Input >> 24) And &HFF))
Return output.ToString()
End Function
End ClassError:
Quote:Do not divide with 0!
