Description
Is your feature request related to a problem? Please describe.
Currently it is possible for an authenticated client to make problematic updates. Currently we try to avoid client software doing these problematic things; however we need a mechanism to prevent these updates occurring.
Here are some of the keys whose values should not be permitted to be overwritten
public:publickey@aliceprivatekey:at_pkam_publickeyshared_key.bob@alice
Describe the solution you'd like
For public:publickey@alice and privatekey:at_pkam_publickey we should prevent their value being modified by client updates (i.e. the update verb handler)
For shared_key.bob@alice we should also prevent the value being modified by client updates.
We should allow metadata to be updated. TBD whether there is some metadata which we should prevent being updated
Describe alternatives you've considered
As the concept of limiting updates to data after its initial creation may have broader applicability, we could introduce a new metadata field, 'immutable', which defaults to false
However we could also just start by putting guards around the three keys named above.
Additional context
No response