rc4.vb

这是RC4加密算法的VB源程序

Public Sub main()
   Dim key As String
   For i = 1 To 16
      Randomize
      key = key & Chr(Rnd * 255)
   Next i
      MsgBox RC4(RC4("Welcome To Plindge Studio!", key), key)
End Sub
Public Function RC4(inp As String, key As String) As String
   Dim S(0 To 255) As Byte, K(0 To 255) As Byte, i As Long
   Dim j As Long, temp As Byte, Y As Byte, t As Long, x As Long
   Dim Outp As String 
   For i = 0 To 255
      S(i) = i
   Next
   j = 1
   For i = 0 To 255
      If j > Len(key) Then j = 1
      K(i) = Asc(Mid(key, j, 1))
      j = j + 1
   Next i
   j = 0
   For i = 0 To 255
      j = (j + S(i) + K(i)) Mod 256
      temp = S(i)
      S(i) = S(j)
      S(j) = temp
   Next i
   i = 0
   j = 0
   For x = 1 To Len(inp)
      i = (i + 1) Mod 256
      j = (j + S(i)) Mod 256
      temp = S(i)
      S(i) = S(j)
      S(j) = temp
      t = (S(i) + (S(j) Mod 256)) Mod 256
      Y = S(t)
      Outp = Outp & Chr(Asc(Mid(inp, x, 1)) Xor Y)
   Next
   RC4 = Outp
End Function