rc4在vb中实现.txt

rc4加密算法在VB中实现

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