Feature Request: Support for Elliptic Curve Keys in JWT Decoder

[sboett-dev]

Currently, the Kuksa.val Databroker only supports RSA keys for JWT decoding:

kuksa-databroker/databroker/src/authorization/jwt/decoder.rs

Line 62 in b5b393d

let decoding_key = match DecodingKey::from_rsa_pem(public_key.into().as_bytes()) {

I’d like to request support for elliptic curve keys, specifically:

• ECDSA with curve secp256r1 (ES256)
• EdDSA with curve ed25519 (EdDSA)

Elliptic curve keys offer several advantages over RSA:

• Smaller key sizes for equivalent security
• Faster signing and verification
• Lower resource usage (ideal for embedded/automotive environments)

Support for these algorithms would improve compatibility with modern JWT practices and enable more efficient cryptographic operations.

[lukasmittag]

Supporting this should at least not hurt :) Since there is no hard requirement from VISS or other standard in the open we decided to use RSA. However @sboett-dev we would appreciate a contribution for this :)