[sda-download] Implement header switch/re-encryption/deencryption

[teemukataja]

If a user sends a public key, re-encrypt the data
related params:

        - name: Public-Key
          in: header
          description: Public Encryption key
          required: false
          schema:
            type: string
        - name: destinationFormat
          in: query
          description: destinationFormat
          required: false
          schema:
            type: string
            default: plain | crypt4gh

Also take a look at https://github.com/neicnordic/sda-download/blob/0aa5af3ce690a610c5c2b369dd9d0ef8d58468d7/internal/database/database.go#L173-L178

[blankdots]

related to neicnordic/sda-download#4 ?

[blankdots]

a vault service that re-encrypts the header would work nicely here.

[pontus]

There is a strong use case for having reencryption/header rewriting/decryption as (at least one) separate microservice(s) as we strongly prefer to not have private key that can decrypt the entire archive within a process that is exposed to end users.

[pontus]

Interface needs to be defined.

[blankdots]

relates with #667 and #364

[blankdots]

done with #668