Title: Security Encryption
Question: How can I do encryption on a string?
Answer:
I wrote this component because I was tired to "Copy & Paste" the same portion of code.
This component are very simple:
- Assign a "BASE KEY" for encryption in the KEY property
- Enter the string to encrypt in the INSTRING property
- The result should appear in the OUTSTRING property
- You can look at the ACTION property to ENCRYPT / DECRYPT a string
unit RVEncrypt;
interface
uses
SysUtils, Classes;
type
TRVEncryptAction = (rveEncrypt,rveDecrypt);
TRVEncrypt = class(TComponent)
private
FAction : TRVEncryptAction;
FKey : String;
FInString : String;
FOutString: String;
procedure FEncrypt;
procedure FDecrypt;
procedure SetAction(Value: TRVEncryptAction);
procedure SetKey(Value: String);
procedure SetInString(Value: String);
protected
{ Protected declarations }
public
{ Public declarations }
published
property Action: TRVEncryptAction read FAction write SetAction;
property Key: String read FKey write SetKey;
property InString: String read FInString write SetInString;
property OutString: String read FOutString;
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('MyPalette', [TRVEncrypt]);
end;
{ TRVEncrypt }
procedure TRVEncrypt.FDecrypt;
var
Len : Byte;
PCounter: Byte;
SCounter: Byte;
begin
FOutString := '';
Len := Length(FKey) div 2;
SCounter := 1;
PCounter := 1;
while SCounter begin
FOutString := FOutString + Chr(Ord(FInString[SCounter]) -
Ord(FKey[PCounter]) - Len);
Inc(SCounter);
Inc(PCounter);
if PCounter Length(FKey) then
PCounter := 1;
end;
end;
procedure TRVEncrypt.FEncrypt;
var
Len : Byte;
PCounter: Byte;
SCounter: Byte;
begin
FOutString := '';
Len := Length(FKey) div 2;
SCounter := 1;
PCounter := 1;
while SCounter begin
FOutString := FOutString + Chr(Ord(FKey[PCounter]) +
Ord(FInString[SCounter]) + Len);
Inc(SCounter);
Inc(PCounter);
if PCounter Length(FKey) then
PCounter := 1;
end;
end;
procedure TRVEncrypt.SetAction(Value: TRVEncryptAction);
begin
if FKey = '' then
exit;
if FAction Value then
begin
FAction := Value;
if FAction = rveEncrypt then
FEncrypt
else
FDecrypt;
end;
end;
procedure TRVEncrypt.SetInString(Value: String);
begin
if FKey = '' then
exit;
if FInString Value then
begin
FInString := Value;
if FAction = rveEncrypt then
FEncrypt
else
FDecrypt;
end;
end;
procedure TRVEncrypt.SetKey(Value: String);
begin
if FKey Value then
begin
FKey := Value;
if FAction = rveEncrypt then
FEncrypt
else
FDecrypt;
end;
end;
end.