[jose] http://www.rfc-editor.org/info/rfc7517

[Ahmet Soormally <[e-mail]>]

Hello Jose,

Hope you are well.

I am writing with regards to proposing a change to rfc7517.

It appears that some identity providers are very purist, and do not
return x5c. It's an optional field.

Whilst other identity providers do provide the x5c certificate.


The x5c certificate is extremely useful. It negates the need for a
library or application to be able to translate the
modulus and exponent.

Many libraries do not support this natively, meaning custom code needs
to be written in order to perform this translation of formats in order
to provide a standardised, interoperable interface & more easily foster
interoperability & federation between multiple IdPs.

https://github.com/asoorm/tyk-go-plugins/blob/master/merge_jwks/merge_jwks.go#L143-L194


It would be great if you could consider making the x5c certificate
mandatory for RSA public keys, or provide any guidance in this regard.


For example, as an API Gateway, I need to be able to support obtaining
JWT public keys from the jwks_uri. and if each IdP does it differently,
then this puts the onus on the gateway to perform the translation, where
it could be very easily implemented at the issuer of the certificate's
side. Further, it will ensure separation of concerns, where the gateway
doesn't need to perform these operations, because the required data is
already presentable in a consistent format.

The certificate issuer will only ever need to update the certificates
upon rotation. But the client using them will need to perform the
translation every time.


With thanks

Ahmet