Certificate::generate_self_signed has incorrect error value for extensions closure

[str4d]

yubikey.rs/src/certificate.rs

Lines 109 to 112 in 0a90dc3

	extensions: F,
	) -> Result<Self>
	where
	F: FnOnce(&mut CertificateBuilder<'_, yubikey_signer::Signer<'_, KT>>) -> der::Result<()>,

This closure only allows returning errors of type der::Error. However, the closure's sole argument is an x509_cert::builder::CertificateBuilder, the methods for which (in particular CertificateBuilder::add_extension) all return x509_cert::builder::Error. The latter contains der::Error as a sub-error, but we can't represent all of the builder's errors in that.

The extensions closure in Certificate::generate_self_signed should be changed to return Result<_, x509_cert::builder::Error> instead of der::Result.

[tony-iqlusion]

cc @baloo

[baloo]

yeah, the cert builder needs an overhaul.