Error: Inability to Connect to Mojang's API

[Pheotis]

Outline of Issue

Attempted Usage

Using the plugin, it is not currently possible for me to register new users using TOTP through the /register TOTP command.

Result of Attempted Usage

On my current installation, 100% of the time, attempting to preform such a registration will result in an error explaining that the plugin could not "load player data from Mojang".
This error message suggests that I may have hit the API's rate limit.

Attempts at Troubleshooting the Issue

Rate Limit Consideration

I have confirmed that the rate limit is not the issue:

• This issue still occurs when 2fa+ is the only plugin operating on the server
• This issue still occurs when that server is the only program operating on the dedicated box
• I am able to pull information manually from the database without any problems using
  curl https://api.mojang.com/users/profiles/minecraft/InteriorCamping

Response time consideration

Previously, pulling data from the API took an abnormal amount of time on my box.

• This caused issues with aspects of several plugins, including the skull feature of EssentialsX (usage of which would cause a five second server freeze).
• After investigating this response time, I have determined that this issue was caused by a mistake in the configuration of my firewall.
  • After correcting that mistake, EssentialsX's skull function appears now functions as intended.
  • After correcting that mistake, 2fa+'s TOTP function is still unable to pull info from the API.

Additional Information

The server is running Paper 641 (1.13.2) on Waterfall 290 on Ubuntu Server 18.04 LTS

Conclusion

• As this issue is not being caused by the rate limit, and as other plugins (EssX) appear to be able to pull information from the API, I was wondering if this might be a plugin-specific issue.
• As a work-a-round, I was wondering if it would be possible to add the ability to manually pass UUIDs to the plugin through command usage such as 2fa register TOTP <UUID>.

[egg82]

I would definitely recommend switching from CraftBukkit/Spigot to Paper if you haven't: https://whypaper.emc.gs - this will fix your current issue at least.

I'll take another look at the (admittedly old) code running that particular lookup and see if I can optimize it or see what's going on. Thanks for the report!

[Pheotis]

Thanks!

This problem resulted from running the register command on a paper 641 instance connected to a waterfall network comprised of other paper instances and a single test spigot 1.8 instance.

I will try again with the outdated spigot instance disabled to see if it changes anything.

[egg82]

I must have skipped over the Paper 641 (1.13.2) somehow; this version of Paper SHOULD have the PlayerProfile API, I believe. In this case, it would be strange if it were still trying to use the BukkitPlayerInfo (rather than the PaperPlayerInfo) class. I'll have to take another look.

[Pheotis]

Thank you for looking in to it; sorry for my late response.

After two tests, I have concluded that this issue occurs exclusively in instances where one of the servers connected to the proxy (and/or the db?) is running a seriously outdated version (in this case, paper 443 (1.8.8)).

If it is possible to fix backwards compatibility for paper 443 (1.8.8), that would also be much appreciated -- I know that it is an absolutely terrible idea in general to use 1.8 versions but for my particular project, I have a relatively strong reason to use it for a singular instance).

Test 1
For the first test, I disabled all other servers connected to the proxy -- which represented all servers connected to 2fa+'s db -- and tested a single instance running 2fa+ 2.4.17 on paper 645 (1.13.2). During this test, I had no difficulties connecting to Mojang's API.

Note that I was still was unable to register new totp players using the plugin due to issue #5 .

Test 2
For the next test, I disabled all other servers connected to the proxy -- which represented all servers connected to 2fa+'s db -- and tested a single instance running 2fa+ 2.4.17 on paper 443 (1.8.8).
During this test, I received the error regarding connections to Mojang's db.