Datei stückchenweise mit TFileStream einlesen

[Luckie]

Entschlüsseln:

Delphi-Quellcode:

          // ignore the file header
          SrcStream.Seek(sizeof(TFileHeader), soFromBeginning);
          // assign the Cipherclass
          CipherClass := Cipher;
          // prepare for decoding
          with CipherClass.Create(PW, nil) do
          begin
            Mode := cmCFB;
            InitKey(PW, nil);
            // as long as we have not reached the end of the source stream
            repeat
              Len := SrcStream.Read(Buffer, SizeOf(Buffer));
              EncodeBuffer(Buffer, Buffer, Len);
              DestStream.WriteBuffer(Buffer, Len);
            until Len = 0;
          end;

Verschlüsseln:

Delphi-Quellcode:

          // write the head into the stream
          DestStream.Write(FileHeader, sizeof(TFileHeader));
          //  prpare vor encoding
          with CipherClass.Create(PW, nil) do
          begin
            Mode := cmCFB;
            InitKey(PW, nil);
            // as long as Len has something to read
            repeat
              Len := SrcStream.Read(Buffer, SizeOf(Buffer));
              EncodeBuffer(Buffer, Buffer, Len);
              DestStream.WriteBuffer(Buffer, Len);
            until Len = 0;
          end;

Was habe ich übersehen?