Enable passphrase for File provider

Could you please provide more info about how the file is encrypted? I think adding a passphrase field would be confusing for users who don't need a passphrase, so what about creating a new key provider plugin that extends the existing File key provider plugin to also ask for the passphrase?

Yes, why not to solve it with new key provider.

In our case we are trying to connect to Snowflake https://docs.snowflake.com/en/user-guide/key-pair-auth
We are using module snowflake where is in contrib/snowflake/src/Authenticator/KeyPairAuthenticator.php called
$private_key_pem = openssl_pkey_get_private($key);
This should be replaced later with something like
$private_key_pem = openssl_pkey_get_private($key, $passphase);
Value of $passphase should come from key module.

Maybe it could be useful for others because openssl_pkey_get_private() can be used by other modules too (e.g. jwt)
https://www.php.net/manual/en/function.openssl-pkey-get-private.php

Thanks for the additional information. Setting back to active.