Leftovers for private groups

[cryptix]

TODO

• re-index when receiving group join messages

Done

move keys to private/keys (bed7170)

this was confusing since there is also a keys.go in the root of the repo for the signing keypair.

right now these keys are used for private messages, so move the package there to make this clearer.

rename sbot.RootLog to sbot.ReceiveLog (ad164d7)

the stream of messages as they arrive

The old term wasn't saying much and also collided with tangle root.

sort by timestamp support (61c5c03)

supports three domains: claimed, received and feed sequence(*)

also supports createFeedStream and messagesByType sorting by claimed timestamp. (TODO: createUserStream)

*: this will become important later once feeds are received out of order.

ditch func (r ref) StorageRef() librarian.Addr from refs package and use TFK instead

See 5ce3d02 for the gory details. tldr: the refs package has fewer internal specifics from go-ssb.
(not merged yet, uses with-branches branch. to be merged with the tangle sort fixes)

fix tangle sort, add Heads() MessageRefs (69e6790)

go.mindeco.de/[email protected] can sort slices of TangledPost now. It's a bit cumbersome to use because of go's type system. A slice of refs.Message needs to be copied into a slice of refs.TangledPost before that can be assigned to (refs.ByPrevious).Items to be sorted.

start interop testing against ssb-tribes

I added two cases to the tests that run against the javascript implementation. One where the JS side creates a group and invites the Go side, the other one does it in reverse (Go creates and invites JS).

This helped me thin out some problems in the DM key derivation (used for 1:1 messages and group invites) and that the cloaked groupID is actually using the read key not the group key for the derivation. So this work now, which is great!

On the negative side, i found two issues that feel like races on the JS side. They both only show if you run the tests over and over again (simply done using go test -count 100). I opened ssbc/ssb-db#316 and ssbc/ssb-db#317 respectively.

add private:bool query parameter

Added to messagesByType and tangles.replies but there is lot's TODO about it still. Before I add it to createLogStream I want to find a solution to the following but that can happen later.
First the code is terrible repetitive and doesn't fold in nicely with the existing margaret query code, similar to the live:bool code there now are two versions to drain a query to muxrpc. Consequently it isn't straight forward to add this to the internal indexing, to support private contact messages for instance.

Another missing feature from the application perspective is how to publish. As it stands an application needs to use groups.publishTo(groupID, { /* content */ }) and this doesn't play nice with existing clients which use publish({content, recps}), looking at the recps array to do the right thing. Using the existing code would leak messages.

[cryptix]

I will do re-indexing as a follow-up PR. This one is big enough as it is.