The AccountBuilder can now skip None Values

[stop5]

By using an Serializer that takes care of the checks and transformations it converts the data into json for the authenticates_request method

[stop5]

I decided to write an own Serializer, because the normal serializer would consume the reference and the Type conversions would be better elsewhere

[Copilot]

Pull Request Overview

This PR updates the AccountBuilder to skip serializing None values by implementing a custom Serialize trait, and refactors the build method to ensure a private key is generated if one is not provided.

• Implements custom Serialize for AccountBuilder to conditionally serialize fields
• Refactors build() to generate and cache a private key if absent
• Leverages serde_json::to_value for cleaner JSON payload generation

[Copilot]

Serializing the external account binding relies on unwrapping the private_key, which could panic if it is None. Consider handling the error more gracefully or ensuring that private_key is always set prior to serialization.

Suggested change

	let payload = serde_json::to_string(&Jwk::new(&self.private_key.clone().unwrap())).unwrap();
	let private_key = match &self.private_key {
	Some(key) => key,
	None => {
	return Err(serde::ser::Error::custom("private_key is not set, cannot serialize externalAccountBinding"));
	}
	};
	let payload = match serde_json::to_string(&Jwk::new(private_key)) {
	Ok(p) => p,
	Err(error) => {
	return Err(serde::ser::Error::custom(format!("Failed to serialize JWK: {}", error)));
	}
	};

[paulgb]

Hi @stop5, thanks for the PR. Could you give a bit more context about why this is necessary? It's been a while since I read the ACME spec, is null not allowed for these?

I wonder if #[serde(skip_serializing_if = "Option::is_none")] would do the same thing here?

[stop5]

The Biggest problem i had trying to do it with derive(Serializer) are the PKey in the AccountBuilder and the ExternalAccountBinding. When the ExternalAccountBinding is added, it needs both keys to convert it into the value required for the request. So i couldn't add it to the ExternalAccountBinding struct

[stop5]

to show the issue here is my code: https://gitea.sebastian-tobie.de/sebastian/racme
With the existing code it causes problems, but with the the patches it works.

[paulgb]

Thanks for that context, but that page is a 404 for me.

[stop5]

i forgot that the repo was created by push. Its now publicly available.