In all of our current uses of os.umask or filesystem.umask, we always temporarily set it to a different value and then restore it using a try/finally block. I expect this pattern to continue.

Because of that, why don't we create a simple function in certbot.util that can be used as a context manager to set umask to a value and restore it to its previous value when exiting the with blo

Unit tests for CertificateReadiness controller

Could follow a similar approach to how the other controllers are tested i.e CertificateIssuing controller

If you create a custom ICertificateAuthorityConfiguration and pass it to say a step-ca authority, with a custom port in the URL the FileSystemAccountStore tries to put the port in the directory name and fails.

Can we change from AuthorityUri to Host?

Simple read function for pkcs8 files - I've built something for this (in the process of.. simple as), will push for review if successful. Additional function in pem.js

Use case:
Verify/Read any pkcs8 file

Openssl steps

1.) Create a private key pair
openssl req -x509 -newkey rsa:4096 -keyout test.pem -out test.crt -days 365 -subj "/C=Test/ST=Test/L=London/O=Pemjs/OU=Pemjs/CN=Pemjs.com" -