Código: Seleccionar todo

Function Autoclave(A : String; B : String; C : Integer) : String;
{'================================================================='}
{' AX: Segundo cifrado de Vigenère                                 '}
{' Uso: Autoclave('Texto', 'Clave', 1/2)                           '}
{' Cifrar (1)  |  Descifrar (2)                                    '}
{'================================================================='}

Var D : LongInt;
Var E : String;
Var F : Integer;
Var G : Integer;
Var H : String;
Var I : String;
Var K : Integer;
Var L : Integer;
Const T = 'ABCDEFGHIJKLMNÑOPQRSTUVWXYZ';
Begin

If (Length(A) = 0) Or (Length(B) = 0) Then Exit;
If Not (C = 1) Then If Not (C = 2) Then Exit;
L := 1;

A := StringReplace(UpperCase(Trim(A)), ' ', '', [rfReplaceAll]);
B := StringReplace(UpperCase(Trim(B)), ' ', '', [rfReplaceAll]);

If Length(B) < Length(A) Then For D := 1 To Length(A) - Length(B) Do E := E + Copy(A, D, 1);

If (C = 2) Then Begin
For D := 1 To Length(A) Do Begin
F := Pos(Copy(A, D, 1), T) - 1;
G := Pos(Copy(B, L, 1), T) - 1;

If (F - G) < 0 Then K := 27 + (F - G) + 1 Else K := (F - G) Mod 27 + 1;

I := I + Copy(T, Pos(Copy(T, K, 1), T), 1);
H := H + Copy(T, Pos(Copy(T, K, 1), T), 1);
If Length(B) = Length(I) Then Begin B := I; I := ''; L := 0; end;
L := L + 1;
end;
end Else Begin
For D := 1 To Length(A) Do Begin
F := Pos(Copy(A, D, 1), T) - 1;
G := Pos(Copy(B + E, D, 1), T) - 1;
H := H + Copy(T, Pos(Copy(T, (F + G) Mod 27 + 1, 1), T), 1);
end;
end;

Autoclave := H;
End;