Encrypt/Decrypt Method

[avinash.lkr]

Hi,
I have a Encryption and Decryption method. But the decryption method is not working for special characters like @, $ and #. Could you please suggest the changes so that it would work for @, $ and #. Below is the encryption/decryption routine.

function nValEncrypt(xVal, j: Integer) : Integer;
begin
RESULT := xVal;
if RESULT > 90 then
RESULT := RESULT - 60
else
if RESULT > 57 then
RESULT := RESULT - 54
else
RESULT := RESULT - 47;
RESULT := RESULT + 5 + j;
if RESULT > 62 then
RESULT := RESULT - 62;
if RESULT < 11 then
RESULT := RESULT + 47
else
if RESULT < 37 then
RESULT := RESULT + 54
else
RESULT := RESULT + 60;
end;


function fnEncryptPassword(psDescryptedPassword : String; pnMaxEncryptedLength : Integer) : String;
var nDL,nSpacing, i, j : Integer;
sEncryptedPassword,
sEncryptedKey :String;
begin
sEncryptedPassword := EmptyStr;
if psDescryptedPassword = EmptyStr then
begin
Result := EmptyStr;
Exit;
end;
sEncryptedKey := 'ai! psDescryptedPassword := Trim(psDescryptedPassword);
nDL := length(psDescryptedPassword);
// nSpacing:=StrToInt(format('%2.0f',[(pnMaxEncryptedLength-nDL)/nDL]));
nSpacing := Trunc((pnMaxEncryptedLength-nDL)/nDL);
j := 1;
while pnMaxEncryptedLength > 0 do
begin
sEncryptedPassword := sEncryptedPassword+
///CHR(Max(ord(psDescryptedPassword[j]),0) + ord(sEncryptedKey[j]));
//CHR(ord(psDescryptedPassword[j]) + 5 + j);
CHR(nValEncrypt(ord(psDescryptedPassword[j]), j));
pnMaxEncryptedLength := pnMaxEncryptedLength - 1;
i := 0;
while((i < nSpacing) and (pnMaxEncryptedLength > 0)) do
begin
sEncryptedPassword :=sEncryptedPassword+
IntToStr(ord(sEncryptedKey[j]));
i := i + 1;
pnMaxEncryptedLength := pnMaxEncryptedLength-1;
end;
j := j + 1;
end;
Result := sEncryptedPassword;
end;
------------------------------------------------------------------------------------
function nValDecrypt(xVal, j: Integer) : Integer;
begin
RESULT := xVal;

if RESULT > 90 then
RESULT := RESULT - 13
else
if RESULT > 57 then
RESULT := RESULT - 7;

RESULT := RESULT - 52 - j;

if RESULT < 1 then
RESULT := RESULT + 62;

if RESULT < 11 then
RESULT := RESULT - 13
else
if RESULT < 37 then
RESULT := RESULT - 6;

RESULT := RESULT + 60;
end;


function DecryptPassword(psEncryptedPassword : String): String;
var nChar, i : Integer;
sDecryptedPassword : String;
begin
RESULT := psEncryptedPassword;
if RESULT <> EmptyStr then
begin
//sEncryptKey :='ai! FOR i := 1 TO LENGTH(RESULT) DO
begin
nChar := nValDecrypt(ord(RESULT[i]),i); //Lennox 10/15/99
if nChar <> 0 then
sDecryptedPassword := sDecryptedPassword + Char(nChar);
end; //FOR
RESULT := sDecryptedPassword;
end;
end;

[Norrit]

Let me guess, you use a Unicode Delphi version.
Above code is Ansi based, so change all string to AnsiString and Char to AnsiChar and this should be fine.

[drama22]

instead you can use a modern library like lockbox or DCPCrypt