// This example hashes data using the SHA method
// from a file to memory in 8K (8192 byte) chunks. 

uses XceedEncryptionLib_TLB

const CHUNKSIZE = 8192; 
var
  xHash : TXceedHashing; 
  xSHA : DXceedSHAHashingMethod; 
  vaBytesRead : OleVariant; 
  vaHashValue : OleVariant; 
  lOffset : Longint; 
  lFileSize : Longint; 
  SourceFile : file of byte; 
begin
  xHash := TXceedHashing.Create( self ); 
  xHash.License( 'your license key' ); 

  xSHA := CoXceedSHAHashingMethod.Create(); 
  try 
    xSHA.HashSize := 256; 
    xHash.HashingMethod := xSHA;  

    AssignFile( SourceFile, 'c:\temp\source.txt' ); 

    Reset( SourceFile ); 

    lFileSize := FileSize( SourceFile ); 

    CloseFile( SourceFile ); 

    lOffset := 0;  

    while lOffset < lFileSize do 
    begin 
     { bEndOfData will be true if the current offset + CHUNKSIZE exceeds the end of the file. } 
     vaBytesRead := xHash.ReadFile( 'c:\temp\source.txt', lOffset, CHUNKSIZE, efpHash,
                                    (lOffset + CHUNKSIZE >= lFileSize) );  

      lOffset := lOffset + vaBytesRead; 
    end;  

    vaHashValue := xSHA.HashValue; 

    { Do something with the HashValue... }  

    ShowMessage( 'Hashing successful!' ); 
  except 
    on xErr : Exception do 
      ShowMessage( xErr.Message ); 
  end;  

  xHash.Free; 
end;