[2 days left] What’s wrong with your cloud strategy? Learn why multicloud solutions matter with Nimble Storage.Register Now

x
?
Solved

How to calculate the hash of a .torrent file ?

Posted on 2008-10-09
1
Medium Priority
?
1,131 Views
Last Modified: 2013-11-22
Hi

I'm trying to calculate hash of a .torrent file, and can't seem to get it to work. What I'm getting is far from what the result should be. I'm using the SHA code from here: http://www.koders.com/delphi/fid872E48EC7C07A22D798357AEC0BABAC9E52BD5AE.aspx?s=sha1 (sha1.pas and tools.pas). And here is my code:

unit Unit1;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, SHA1;

type
  TForm1 = class(TForm)
    nazwaPliku: TEdit;
    Button1: TButton;
    infoLabel: TLabel;
    procedure Button1Click(Sender: TObject);
    function DekodujZnaki(Znak : char) : string;
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function TForm1.DekodujZnaki(Znak : char) : string;
const
  TablicaHexow: Array[0..15] of char = '0123456789ABCDEF';

var
  b : Byte;

begin
  b := Byte(Znak);
  Result := TablicaHexow[b shr 4] + TablicaHexow[b and $0F];
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  FS : TFileStream;
  dane : array of byte;
  i, j : integer;
  Context : TSHA1Context;
  Digest : TSHA1Digest;
  wynik : string;

begin
  if not(SHA1SelfTest) then
    begin
      infoLabel.Caption := 'BBd !!! Test moduBu hashujcego si nie powiódB !!!';
      Exit;
    end;
  FS := TFileStream.Create(nazwaPliku.Text, fmOpenRead);
  SetLength(dane, FS.Size);
  for i := 0 to Length(dane) - 1 do
    FS.Read(dane[i], 1);
  FreeAndNil(FS);
  for i := 0 to Length(dane) - 1 do
    if ((char(dane[i]) = '4') AND (char(dane[i + 1]) = ':') AND
        (char(dane[i + 2]) = 'i') AND (char(dane[i + 3]) = 'n') AND
        (char(dane[i + 4]) = 'f') AND (char(dane[i + 5]) = 'o')) then
            begin
              for j := 0 to Length(dane) - 1 do
                dane[j] := dane[i + j];
              SetLength(dane, Length(dane) - i);
              Break;
            end;

  SHA1Init(Context);
  SHA1Update(Context, @dane[1], length(dane));
  SHA1Final(Context, Digest);
  wynik := '';
  for i := 0 to Length(Digest) - 1 do
    wynik := wynik + DekodujZnaki(char(Digest[i]));
  infoLabel.Caption := 'Hash: ' + wynik;
end;

end.

Any help would be appreciated.
0
Comment
Question by:tadeusz81
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 

Accepted Solution

by:
tadeusz81 earned 0 total points
ID: 22682653
this Q can be closed now... I got it to work... code was written ok, except for one little error

this line: SHA1Update(Context, @dane[1], length(dane));

should be: SHA1Update(Context, @dane[0], length(dane));

and it works great.
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this post we will learn different types of Android Layout and some basics of an Android App.
The SignAloud Glove is capable of translating American Sign Language signs into text and audio.
Six Sigma Control Plans
Progress
Suggested Courses

649 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question