[Bug]: Remove the use of periods in environment variables

[jonbarrow]

Checked Existing

• I have checked the repository for duplicate issues.

What happened?

Currently the DNS server expects custom mapped domains in environment variables to be fully qualified domains, including using periods. However as pointed out by @mrjvs this is not safe. Environment variables [A-Za-z0-9_]+ can only be, and some systems may filter out keys which have invalid characters.

What did you expect to happen?

Use a different structure for SSSL_DNS_MAP environment variables. The way jvs solved this was just by removing periods (examplecom rather than example.com). But this is, honestly, ugly. I suggest either

• SSSL_DNS_MAP_example_com
• SSSL_DNS_MAP_EXAMPLE_COM

We would then need to modify the incoming domain during lookup

Steps to reproduce?

No response

Other relevant information. (OPTIONAL)

No response

[DaniElectra]

Removing periods also wouldn't work since we then don't know how the hostname is formatted. I think we can use snake_case and replace the underscores with dots? example_com => example.com

[jonbarrow]

Removing periods also wouldn't work since we then don't know how the hostname is formatted

I'm not sure what you mean? The hostname in the DNS request would look like account.nintendo.net. All we'd have to do is remove the periods and that becomes accountnintendonet, which would lineup with the environment variable

[DaniElectra]

I didn't consider that, disregard then

[christophe-asselin]

I'd be open to pick this up. Only problem is that I do not own a Wii U, so I would be unable to test this with a physical set up. I can test by making a couple of manual requests, but I don't know if that is good enough.

My only question is: do we want the server to stay backwards compatible with the old environment variable format or make the new format mandatory?