[sda-download] Alternate ways of passing public key

[pontus]

To facilitate use, it would be nice if we could avoid the need for a special header to pass the public key to encrypt downloads for.

This would mean some form of pre-registration. There has been various discussions (e.g. putting in a database), but no implementation that I know of.

One alternate way could be to have a service (e.g. login) allowing to issue a visa (e.g. considering the key a linked identity), possibly a good idea to reach out to LS Login .

LS Login also supports management of ssh keys, including ed25519 keys. Technically it's a different encoding than the native crypt4gh public key format but it encodes the same thing and can be used as a bearer (common crypt4gh tooling also supports reading ed25519 ssh keys directly).