Including sync contributions into a block affects validator rewards.
When we have not received aggregate sync contributions, but have seen
individual messages, we can produce the contributions locally, improving
validator rewards when subscribing to all subnets or when having a
non-aggregating attached validator in the sync committee.
`produceSyncAggregate` is called in new slot when block is produced,
while the other functions in `sync_committee_msg_pool` are called in
previous slot. So, need to subtract 1 slot when producing sync aggregate
to accept the signatures using the old digest during fork transition.
`SyncCommitteeMsgPool` grouped messages by their `beacon_block_root`.
This is problematic around sync committee period boundaries and forks.
Around sync committee period boundaries, members from both the current
and next sync committee may sign the same `beacon_block_root`; mixing
the signatures from both committees together is a mistake. Likewise,
around fork transitions, the `signing_root` changes, so those messages
also need to be segregated.
* correctly report ignored contributions in metrics
* avoid counting subset contributions in vmon (bring in line with
attestation aggregates)
* avoid signature checks for subset attestations
A being a non-strict subset is a sufficient condition to ignore.
* move duty tracking code to `ActionTracker`
* fix earlier duties overwriting later ones
* re-run subnet selection when new duty appears
* log upcoming duties as soon as they're known (vs 4 epochs before)
* Harden CommitteeIndex, SubnetId, SyncSubcommitteeIndex
Harden the use of `CommitteeIndex` et al to prevent future issues by
using a distinct type, then validating before use in several cases -
datatypes in spec are kept simple though so that invalid data still can
be read.
* fix invalid epoch used in REST
`/eth/v1/beacon/states/{state_id}/committees` committee length (could
return invalid data)
* normalize some variable names
* normalize committee index loops
* fix `RestAttesterDuty` to use `uint64` for `validator_committee_index`
* validate `CommitteeIndex` on ingress in REST API
* update rest rules with stricter parsing
* better REST serializers
* save lots of memory by not using `zip` ...at least a few bytes!
* batch-verify sync messages for a small perf boost
Generally reuses the same structure as attestation and aggregate
verification
* normalize `signatures` and `signature_batch` to use the same pattern
of verification
* normalize parameter names, order etc for signature stuff in general
* avoid calling `blsSign` directly - instead, go through `signatures`
consistently
