Month: March 2017

The first part of this article describes a simple but limited way to read password encrypted zip files with a derived TZipFile class. The limitations are

1. it can only read but not create encrypted zip files
2. the size of the zip files is limited by the available memory

While this solution does the job in the scenario it was built for, I cannot say that I was really satisfied with that. So I investigated ways how these limitations can be overcome.

It turned out that it was not that easy as I anticipated. Continue reading “TZipFile with Password Encryption (Part 2)”

As some of you might already know, Delphi (at least since XE2) comes with a built-in TZipFile class for reading and writing zip files. It is a rather basic class with only limited functionality, but this might just be enough for quite a couple of day-to-day tasks.

During a recent migration of a project from Delphi 7 to Delphi 10.1 Berlin I was facing the decision to either fix the current zip implementation (based on external DLLs) or switch to the stock implementation using TZipFile. The second option would also have the advantage of getting rid of distributing the DLLs. So I headed for that one.

Well, as always when you think you have found the right solution and start coding – reality steps in. Some of the zip files we had to read were password protected. Unfortunately TZipFile doesn’t support password encryption out of the box. Continue reading “TZipFile with Password Encryption”