對字串進行簡單的加密和解密處理
//加密字串
function encryptstr(const s:string; skey:string):string;
var
i,j: integer;
hexS,hexskey,midS,tmpstr:string;
a,b,c:byte;
begin
hexS :=myStrtoHex(s);
hexskey:=myStrtoHex(skey);
midS :=hexS;
for i:=1 to (length(hexskey) div 2) do
begin
if i<>1 then midS:= tmpstr;
tmpstr:='';
for j:=1 to (length(midS) div 2) do
begin
a:=strtoint('$'+midS[2*j-1]+midS[2*j]);
b:=strtoint('$'+hexskey[2*i-1]+hexskey[2*i]);
c:=a xor b;
tmpstr := tmpstr+myStrtoHex(chr(c));
end;
end;
result := tmpstr;
end;
//解密字串
function decryptstr(const s:string; skey:string):string;
var
i,j: integer;
hexS,hexskey,midS,tmpstr:string;
a,b,c:byte;
begin
hexS :=s;//應該是該字串
if length(hexS) mod 2=1 then
begin
showmessage('密文錯誤!');
exit;
end;
hexskey:=myStrtoHex(skey);
tmpstr :=hexS;
midS :=hexS;
for i:=(length(hexskey) div 2) downto 1 do
begin
if i<>(length(hexskey) div 2) then midS:= tmpstr;
tmpstr:='';
for j:=1 to (length(midS) div 2) do
begin
a:=strtoint('$'+midS[2*j-1]+midS[2*j]);
b:=strtoint('$'+hexskey[2*i-1]+hexskey[2*i]);
c:=a xor b;
tmpstr := tmpstr+myStrtoHex(chr(c));
end;
end;
result := myHextoStr(tmpstr);
end;