chore: Log HTTP request body on signature verification failure

[randombit]

There have been reports both internally and in support channels of ingress messages failing signature verification. So far these have not been reproducible, and the cause is unknown. To assist debugging, if verification fails log the HTTP request body.

[fspreiss]

Just stumbled upon

impl AsRef<HttpRequest<SignedIngressContent>> for SignedIngress {
    fn as_ref(&self) -> &HttpRequest<SignedIngressContent> {
        &self.signed
    }
}

so theoretically, the new signed(&self) is not strictly necessary as the same can be achieved with the existing as_ref(). For people who don't know this code well (like me), this is not obvious, however.

[fspreiss]

nit: Optionally we could make this

pub(crate) fn validation_error_to_http_error<C: std::fmt::Debug + HttpRequestContent>(
    request: &HttpRequest<C>,
    err: RequestValidationError,
    log: &ReplicaLogger,
) -> HttpError {

i.e,. we don't need to take the message_id separately, because we can just get it from the request via request.id().

[fspreiss]

Do we have sufficient debug info when just logging request.content() rather than request?

If we log the entire request, we also get the HttpRequest::auth: Authentication part, which contains the signature and signer_pubkey (and sender_delegation) for authenticated requests.