SHA1 hashing in Delphi XE

Question

I\'m in the process of implementing XML digital signatures. I\'m starting with little steps, so right now I want to solve the problem of SHA-1 hashing.

There are lot

Answer 1

Leonardo, i think which your problem is the UNICODE when you uses a function to hash a string you are passing a array (buffer) of bytes. so when you pass the abc string in Delphi XE, your are hashing a buffer like this 61 00 62 00 63 00 (Hex representation)

check this sample application which uses the Windows crypto functions from the Jwscl library (JEDI Windows Security Code Lib)

program Jwscl_TestHash;

{$APPTYPE CONSOLE}

uses
  JwsclTypes,
  JwsclCryptProvider,
  Classes,
  SysUtils;

function GetHashString(Algorithm: TJwHashAlgorithm; Buffer : Pointer;Size:Integer) : AnsiString;
var
  Hash: TJwHash;
  HashSize: Cardinal;
  HashData: Pointer;
  i       : Integer;
begin
  Hash := TJwHash.Create(Algorithm);
  try
    Hash.HashData(Buffer,Size);
    HashData := Hash.RetrieveHash(HashSize);
    try
        SetLength(Result,HashSize*2);
        BinToHex(PAnsiChar(HashData),PAnsiChar(Result),HashSize);
    finally
      TJwHash.FreeBuffer(HashData);
    end;
  finally
    Hash.Free;
  end;
end;


function GetHashSHA(FBuffer : AnsiString): AnsiString;
begin
   Result:=GetHashString(haSHA,@FBuffer[1],Length(FBuffer));
end;

function GetHashSHA_Unicode(FBuffer : String): String;
begin
   Result:=GetHashString(haSHA,@FBuffer[1],Length(FBuffer)*SizeOf(Char));
end;

begin
 try
     Writeln(GetHashSHA('abc'));
     Writeln(GetHashSHA('abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq'));
     Writeln(GetHashSHA_Unicode('abc'));
     Writeln(GetHashSHA_Unicode('abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq'));
     Readln;
 except
    on E:Exception do
    begin
        Writeln(E.Classname, ':', E.Message);
        Readln;
    end;
 end;

end.

this return

abc AnsiString

A9993E364706816ABA3E25717850C26C9CD0D89D

abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq AnsiString

84983E441C3BD26EBAAE4AA1F95129E5E54670F1 for

abc unicode

9F04F41A848514162050E3D68C1A7ABB441DC2B5

abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq Unicode

51D7D8769AC72C409C5B0E3F69C60ADC9A039014