' SND-Algorhitmus zum Ver- und Entschlüßeln von Computerdaten
' Simple Number Based Decryption
' (C) Mittwoch 07.05.2003 - Dennis Schulmeister
' Alle Rechte vorbehalten

Randomize

Proc SND_Crypt
        Parameters PlainString$, Password$
        Declare i%, n%, CryptedString$, Ord$, RND%, Klammer$, WarOffen%
        Declare PWDOrd%, j%, nPWD%
        
        Password$ = @Trim$(Password$)
        Case @EQU$(Password$,""):Return PlainString$
       
        n% = @Len(PlainString$)
        nPWD% = @Len(Password$)

        WhileNot @Equ(i%, n%)
                inc i%
                inc j%

                PWDOrd% = @Ord(@Mid$(Password$, j%, 1))
                Ord$ = @Str$(@Int(@Add(@Ord(@Mid$(PlainString$,i%,1)),PWDOrd%)))
                Ord$ = @Add$(@Mkstr$("0",@Sub(3,@Len(Ord$))),Ord$)
                RND% = @Int(@RND(i%))
                If @Not(@Mod(RND%,2))
                        If WarOffen%
                                WarOffen% = 0
                                Klammer$ = ")"
                        Else
                                WarOffen% = 1
                                Klammer$ = "("
                        EndIf
                Else
                        Klammer$ = ""
                EndIf
                
                CryptedString$ = @Add$(@Add$(CryptedString$,Klammer$), Ord$)
                
                Case @Not(@Mod(i%,nPWD%)):j% = 0
        Wend
        
        Case (WarOffen%): CryptedString$ = @Add$(CryptedString$,")")
        Return CryptedString$
EndProc

Proc SND_Decrypt
        Parameters CryptedString$, Password$
        Declare PlainString$, i%, j%, n%, nPWD%, Ord$, PWDOrd%
        
        Password$ = @Trim$(Password$)
        Case @Equ$(Password$,""): Return CryptedString$
        
        CryptedString$ = @Translate$(CryptedString$,"(","")
        CryptedString$ = @Translate$(CryptedString$,")","")
        
        n% = @Div(@Len(CryptedString$),3)
        nPWD% = @Len(Password$)
        j% = 1
                
        WhileNot @Equ(i%, n%)
                PWDOrd% = @Int(@Ord(@Mid$(Password$, j%, 1)))
                Ord$ = @Mid$(CryptedString$,@Add(@Mul(i%,3),1),3)
                Ord$ = @Chr$(@Int(@Sub(@Val(Ord$),PWDOrd%)))
                PlainString$ = PlainString$ + Ord$

                inc i%
                inc j%              

                Case @Not(@Mod(i%,nPWD%)):j% = 1
        Wend
        
        Return PlainString$
EndProc