In Altair, light client sync protocol exchanges `BeaconBlockHeader`
structures for tracking current progress. Wrapping `BeaconBlockHeader`
inside a `LightClientHeader` allows future extensions of this header,
e.g., to also track `ExecutionPayloadHeader`.
Note: This changes the JSON REST format by adding a `beacon` nesting.
For SSZ, the serialization format stays same (but overall root changes).
* Add @description decorator
* Unify test case naming style
* more clean ups
* Altair tests cleanup
* Clean up Altair and Bellatrix `process_deposit` tests
* Clean up Bellatrix tests
* Clean up Capella tests
* PR feedback from @ralexstokes
* Add comments on the deposit fork version tests
* Remove `test_incorrect_sig_other_version` since it is duplicate to `test_ineffective_deposit_with_bad_fork_version`
* Add `test_ineffective_deposit_with_current_fork_version`
While the light client sync protocol currently provides access to the
latest `BeaconBlockHeader`, obtaining the matching execution data needs
workarounds such as downloading the full block.
Having ready access to the EL state root simplifies use cases that need
a way to cross-check `eth_getProof` responses against LC data.
Access to `block_hash` unlocks scenarios where a CL light client drives
an EL without `engine_newPayload`. As of Altair, only the CL beacon
block root is available, but the EL block hash is needed for engine API.
Other fields in the `ExecutionPayloadHeader` such as `logs_bloom` may
allow light client applications to monitor blocks for local interest,
e.g. for transfers affecting a certain wallet. This enables to download
only the few relevant blocks instead of every single one.
A new `LightClientStore` is proposed into the Capella spec that may be
used to sync LC data that includes execution data. Existing pre-Capella
LC data will remain as is, but can be locally upgraded before feeding it
into the new `LightClientStore` so that light clients do not need to run
a potentially expensive fork transition at a specific time. This enables
the `LightClientStore` to be upgraded at a use case dependent timing at
any time before Capella hits. Smart contract and embedded deployments
benefit from reduced code size and do not need synchronization with the
beacon chain clock to perform the Capella fork.
Introduce `get_lc_beacon_slot` and `get_lc_beacon_root` accessors
similar to `get_current_slot(state)` to account for future extensions
to the light client header structure that may override how those fields
are accessed. Idea is to extend with execution accessors in the future.
Introduce `block_to_light_client_header` helper function to enable
future forks to override it with additional info (e.g., execution),
without having to change the general light client logic.
Likewise, update existing light client data creation flow to use
`block_to_light_client_header` and default-initialize empty fields.
Furthermore, generalize `create_update` helper to streamline test code
using `block_to_light_client_header`.
Note: In Altair spec, LC header is the same as `BeaconBlockHeader`.
however; future forks will extend it with more information.
Additionally, it makes the Fiat-Shamir hashing logic more robust by making the challenges independent of each other. It also makes it more efficient to implement by moving both challenge computations to a single function needing a single transcript hash.
Co-authored-by: George Kadianakis <desnacked@riseup.net>
Co-authored-by: Dankrad Feist <mail@dankradfeist.de>
When defining a fork transition test, additional spec forks are made
available through `@with_phases(..., other_phases=...)`.
The `with_config_overrides` decorator only applies to the primary phase
so far, which can be unexpected. `with_config_overrides` is adjusted to
override config in subsequent `other_phases` as well.
This commit changes the public API of the KZG library to the following high-level API:
```
- verify_kzg_proof()
- compute_aggregate_kzg_proof()
- verify_aggregate_kzg_proof()
- blob_to_kzg_commitment()
```
compared to the previous much more low-level API:
```
- compute_powers()
- matrix_lincomb()
- lincomb()
- bytes_to_bls_field()
- evaluate_polynomial_in_evaluation_form()
- verify_kzg_proof()
- compute_kzg_proof()
```
This means that all the cryptographic logic (including Fiat-Shamir) is now isolated and hidden in the KZG library and the `validator.md` file ends up being significantly simplified, only calling high-level KZG functions.
Some additional things that this commit does:
- Moves all EIP4844 cryptography into polynomial-commitments.md
- Improves the Fiat-Shamir stack by removing the need for SSZ and by introducing simple domain separators
Co-authored-by: Kevaundray Wedderburn <kevtheappdev@gmail.com>
Co-authored-by: Hsiao-Wei Wang <hsiaowei.eth@gmail.com>
Co-authored-by: Dankrad Feist <mail@dankradfeist.de>
Moving the `is_post_xxx` functions to a separate module allows `genesis`
to also use them (cyclic import from `context` prevented this before).
This allows removing `FORKS_BEFORE_ALTAIR` and `FORKS_BEFORE_BELLATRIX`
constants and adding a more general `is_post_fork` function that needs
less maintenance. This then allows definition of `with_all_phases_from`
to streamline the implementation of the `with_xxx_and_later` decorators.
Future light client protocol extensions may include data from the block
in addition to data from the state, e.g., `ExecutionPayloadHeader`.
To prepare for this, also pass the block to the corresponding functions.
In practice, blocks access is easier than historic state access, meaning
there are no practical limitations due to this change.
Hsiao-Wei Wang
Danny Ryan
Etan Kissling
protolambda
Alex Stokes
kevaundray
George Kadianakis
terence tsao
inphi
Potuz