Port pgsodium to Windows

[Godwottery]

I have ported pgsodium to Windows. It need some minor changes in order to build. It needs plenty of clean-up in order to be in such a state that it can be upstreamed.

Do these changes have a chance of being accepted? Or would you prefer to keep Windows-support out?

[michelp]

I don't mind windows support at all as long as I can run the tests with it using github actions. I'm fine with code cleanups in general, what kind of upstreaming were you thinking about? I've been considering using a git pre-commit hook to enforce the postgres code linter but haven't had the time to implement it yet. I'd prefer an automation based solution to a one-time manual clean up pass.

[Godwottery]

I am going to double check, but the big change was to PGDLLEXPORT to all the external functions. From what I understand this should be compatible with the other OSes as well. This should pass any automatic linters as well. It is defined empty in src/include/c.h, with the Windows specific ones in src/include/port/win32.h.

I also made some other changes that I am not sure why they were necessary, so those I would verify first. The clean-up necessary would be only in my new changes. They should not have a problem passing the postgres linter. My changes will be as small as possible, only what is strictly required will be included.

Building it requires some work (see for example https://www.highgo.ca/2020/05/15/build-postgresql-and-extension-on-windows/), which I am unsure how to incorporate in a good way.

I will work on it some more and then prepare a pull request.

[andrewwasielewski]

@Godwottery I am very interested in Windows support for pgsodium - would you be able to share your port?

[Godwottery]

I have temporarily lost access to the machine where I had my port, so I can only give you a rough outline, but it should be enough to manage for yourself.

Check https://www.highgo.ca/2020/05/15/build-postgresql-and-extension-on-windows/ to find out how to build a PostgreSQL extension on Windows.

The change to the code that is necessary is "Add PGDLLEXPORT to all the exported functions."

The issue that I was looking into when I got stuck last time was the call to popen in pgsodium.c ( ... = popen (getkey_script, "r") ... ), I do not think that this should be needed since it is also included in the portability layer, but I made some changes that I do not understand in order to get it to work.

Give it a try with the PGDLLEXPORT additions, and I'll try to have a look and see if I can access a copy of my changes.

[andrewwasielewski]

Thanks for your response - I found that blog post/example very helpful when attempting my windows port. It seems to closely mirror this older guide also: https://www.2ndquadrant.com/en/blog/compiling-postgresql-extensions-visual-studio-windows/

After adding PGDLLEXPORT to the source code (where applicable), I am able to build the pgsodium.dll with Visual Studio 2019, however, when trying to install the extension in my database, I get following error:

CREATE EXTENSION pgsodium;
ERROR:  security label provider "pgsodium" is not loaded

I haven't spent too much time trying to debug this yet - did you see something similar when working on your port? Thanks.

[Godwottery]

Yes, I had similar problems.
There are a number of possible issues that I would look at first:

• might be that it can not find libsodium.dll,
• might be that you have built the wrong CPU architecture (32-bit vs 64-bit),
• or there is something that doesn't work in the initialization portion.

[andrewwasielewski]

Thanks. After throwing in some log messages, I realized I missed adding the PGDLLEXPORT to_PG_init(). Was able to fix up the shared_preload_library section as well and get the extension working.

[Godwottery]

I got access to my changes. Apart from the PGDLLEXPORT I also changed popen(getkey_script, ... to _popen(getkey_script and a number of related changes. These ones I do not understand why I made, I think it might just be a missing import that didn't pull in the Windows compatability layer properly. Did you have to make any such changes?

[andrewwasielewski]

I originally thought that would be required too, but actually _popen is not necessary since port.h defines #define popen(a,b) pgwin32_popen(a,b) which allows spaces in the path (adds enclosing quotations). I did need to rewrite the getline functionality