How good it is I really cannot say, and I don't really know how I would go about testing it if I had to, but the Jedi-library contains some code for shredding files on delete. I don't even know at the moment if they are still carrying it but if so you might want to check it out!
from Robert Meek dba "Tangentals Design" e-mail: [EMAIL PROTECTED] Freelance Windows Programming for XP and Vista Also proud to be a Moderator of the "Delphi-List" at elists.org "Reality cannot be explained...only enjoyed or endured as your current perspective allows!" -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rob Cameron Sent: Monday, November 12, 2007 7:56 AM To: [email protected] Subject: Deleting - and shredding - a file In a current project I'm required to detect a text file in a folder, encrypt it and send it to a recipient. No problem; I'll use LockBox for the encryption. The files contain health data which may be sensitive and after confirming receipt of the data, the files should be deleted from the folder. The customer has also asked that the files should be shredded. A professional disk recovery exercise is unlikely, but they do want to avoid a deleted file being recovered if one of their laptops is lost or stolen. I don't know enough about how Windows handles files: would it be enough to overwrite the file, maybe something like the code below? This relies on Windows saving the file(s) in exactly the same locations on disk and I suspect this will not always be the case. Does anyone know of a better way, or a component that will shred a file from within a Delphi app? Many thanks for all suggestions, Rob procedure OverWriteandDelete(FileName: string; N: integer); // Overwrite a file N times then delete it // File2String(FileName) and String2File are taken from "ExeMod" written by G.A. Carpenter // (see below) var TempString: string; k: integer; C: char; begin TempString := File2String(FileName); // overwrite the file N times, saving to disk each time for k := 1 to N do begin C := chr(65 + random(50)); String2File(StringOfChar(C, length(TempString)), FileName); end; // empty the string in memory ZeroMemory(@TempString, SizeOf(TempString)); // delete the file from disk DeleteFile(FileName); end; // These two methods are taken from "ExeMod" written by G.A. Carpenter: //This code can write any string to disk as a file procedure String2File(String2BeSaved, FileName: string); var MyStream: TMemoryStream; begin if String2BeSaved = '' then exit; SetCurrentDir(ExtractFilePath(Application.ExeName)); MyStream := TMemoryStream.Create; try MyStream.WriteBuffer(Pointer(String2BeSaved)^, Length(String2BeSaved)); MyStream.SaveToFile(FileName); finally MyStream.Free; end; end; //This code can read any file from disk and into a string: function File2String(FileName: string): string; var MyStream: TFileStream; MyString: string; begin MyStream := TFileStream.Create(FileName, fmOpenRead or fmShareDenyNone); try MyStream.Position := 0; SetLength(MyString, MyStream.Size); MyStream.ReadBuffer(Pointer(MyString)^, MyStream.Size); finally MyStream.Free; end; Result := MyString; end; _______________________________________________ Delphi mailing list -> [email protected] http://lists.elists.org/cgi-bin/mailman/listinfo/delphi _______________________________________________ Delphi mailing list -> [email protected] http://lists.elists.org/cgi-bin/mailman/listinfo/delphi
