Verifying Postmark TLS configuration changes against temporary URL "api-ssl-temp.postmarkapp.com"

[jvopalensky]

The Feb. 16, 2021 announcement (https://postmarkapp.com/updates/upcoming-tls-configuration-changes-for-api-users-action-may-be-required) states that on April 13, 2021 Postmark API endpoint security will be updated as follows:

1. TLSv1 access will not be allowed.
2. All RC4 and low-strength ciphers will not be allowed.
3. HSTS headers will be included.

I like to be sure that by then using this NuGet package our code will still work. But I am not clear how I can do that without creating a private NuGet package that modifies the hard-coded default Base URL parameter value (apiBaseUri) from "api.postmarkapp.com" to "api-ssl-temp.postmarkapp.com".

Note: I created a forked version at https://github.com/firmwater/postmark-dotnet that replaces this apiBaseUri. But I rather use an official WildBit postmark-dotnet NuGet package that allows anyone to change the apiBaseUri value on startup. Is there some environment variable that can be used to control this base API URI value?

I see in your test cases there is BASE_URL config variable. But I cam not clear how I can initialize it in our application running n our cloud server. As stated in https://github.com/wildbit/postmark-dotnet/issues/78 by atheken:

If you'd like to run the tests locally, these are the necessary env vars, which can also be stored as keys in a file called testing_keys.json in a parent directory of the repo:

https://github.com/wildbit/postmark-dotnet/blob/master/src/Postmark.Tests/ClientBaseFixture.cs#L19-L29

If a readme on how to configure these would be useful, that's something we can add.

[gary-lg]

Hi @jvopalensky,

You can specify a different base URL when instantiating an instance of the PostmarkClient or PostmarkAdminClient by passing the optional baseApiUrl parameter to the constructor.

For example:

var pmClient = new PostmarkClient(pmServerToken, "https://api-ssl-temp.postmarkapp.com");

Because you can set the base URL at the point of construction you are free to load the URL from a config file, environment variable or anywhere else. The postmark library by itself does not read any config or environment values. The environment values in the test fixtures exist so we can share the test suite without exposing the tokens we use for our own verification.

If you need anything else please feel free to comment on this thread.

[jvopalensky]

No need for this. I now see there is way to override the default API URL in PostmarkClient() constructor.

[jvopalensky]

Thanks Gary. I also found this more or less at the same time you posted your comment.

[jhaldi]

Thank you for this - big help!!