Asp Programming Code Examples Asp > Mathematics Code Examples RC4 Class RC4 Class <% Option Explicit Dim ObjRC4 Set ObjRC4 = New clsRC4 ObjRC4.Key = "Joe" Response.Write """" & ObjRC4.Crypt("hello") & """" Set ObjRC4 = Nothing ' -------------------------------------- Class clsRC4 Private mStrKey Private mBytKeyAry(255) Private mBytCypherAry(255) Private Sub InitializeCypher() Dim lBytJump Dim lBytIndex Dim lBytTemp For lBytIndex = 0 To 255 mBytCypherAry(lBytIndex) = lBytIndex Next ' Switch values of Cypher arround based off of index and Key value lBytJump = 0 For lBytIndex = 0 To 255 ' Figure index To switch lBytJump = (lBytJump + mBytCypherAry(lBytIndex) + mBytKeyAry(lBytIndex)) Mod 256 ' Do the switch lBytTemp = mBytCypherAry(lBytIndex) mBytCypherAry(lBytIndex) = mBytCypherAry(lBytJump) mBytCypherAry(lBytJump) = lBytTemp Next End Sub Public Property Let Key(ByRef pStrKey) Dim lLngKeyLength Dim lLngIndex If pStrKey = mStrKey Then Exit Property lLngKeyLength = Len(pStrKey) If lLngKeyLength = 0 Then Exit Property mStrKey = pStrKey lLngKeyLength = Len(pStrKey) For lLngIndex = 0 To 255 mBytKeyAry(lLngIndex) = Asc(Mid(pStrKey, ((lLngIndex) Mod (lLngKeyLength)) + 1, 1)) Next End Property Public Property Get Key() Key = mStrKey End Property Public Function Crypt(ByRef pStrMessage) Dim lBytIndex Dim lBytJump Dim lBytTemp Dim lBytY Dim lLngT Dim lLngX ' Validate data If Len(mStrKey) = 0 Then Exit Function If Len(pStrMessage) = 0 Then Exit Function Call InitializeCypher() lBytIndex = 0 lBytJump = 0 For lLngX = 1 To Len(pStrMessage) lBytIndex = (lBytIndex + 1) Mod 256 ' wrap index lBytJump = (lBytJump + mBytCypherAry(lBytIndex)) Mod 256 ' wrap J+S() ' Add/Wrap those two lLngT = (mBytCypherAry(lBytIndex) + mBytCypherAry(lBytJump)) Mod 256 ' Switcheroo lBytTemp = mBytCypherAry(lBytIndex) mBytCypherAry(lBytIndex) = mBytCypherAry(lBytJump) mBytCypherAry(lBytJump) = lBytTemp lBytY = mBytCypherAry(lLngT) ' Character Encryption ... Crypt = Crypt & Chr(Asc(Mid(pStrMessage, lLngX, 1)) Xor lBytY) Next End Function End Class %>