* Add simple rate limiting mechanism

* Add tests

* Small test cleanup

* Hook MaxRequests into runtimes

* Make AncestryProof type more flexible

* Only import single finalized header instead of a chain

* Fix unchecked header import tests

* Add option for limiting ancestry proof size

* Update finality verifier Config in runtimes

* Update some documentation

* Fix Clippy warning

* Allow AncestryChecker to return proof size

Stops us from abusing the `Size` trait

* Remove Size impl for Vec<T>

* Remove size contraints for ancestry proofs

With different proof types its unclear how to "size" should be interpreted,
so we remove this requirement all together to avoid confusion.

* Get pallet compiling with FRAME v2

* Get tests compiling

* Stop printing metadata in tests

* Remove more metadata related code

* Remove unecessary storage attribute

* Add skeleton for `pallet-finality-verifier`

* Sketch out implementation for importing finality proofs

* Get pallet compiling

* Introduce skeleton for mock runtime

* Start using real Grandpa types in finality pallet

* Redefine types in header chain primitives crate

* Implement HeaderChain for Substrate bridge pallet

* Plug Substrate Bridge Pallet into verifier mock

* Fix compilation of `header-chain` primitives

* Start writing to base pallet storage

* Add first "cross-pallet" test

* Move keyring primitives used in tests to shared crate

* Stop pulling `std` deps into `no_std` builds

* Revert "Stop pulling `std` deps into `no_std` builds"

This reverts commit f74dd660.

* Revert "Move keyring primitives used in tests to shared crate"

This reverts commit b774fa73.

* Use new SS58Prefix type in mock

* Start using `bp-test-utils` in finality pallet

* Start using real justification code

* Get a test working with real justification verification

* Add basic tests for invalid proofs

* Get rid of AncestryProof config type

* Add error types to transaction outcome

* Bound number of headers allowed in a single ancestry proof

* Disallow invalid authority sets

* Remove unused items

* Add some documentation

* Get rid of Clippy warnings

* Rename BaseHeaderChain to TransactionVerifier

* Remove unused code

* Make dummy trait implementations more generic

* Fix more Clippy complaints

* Update tests to use fix for duplicate headers

* Fix benchmarking compilation

* Rename TransactionVerifier to InclusionProofVerifier

* Move justification module to header-chain primitives crate

* Get justification module compiling in new location

* Get justification module tests compiling

* Use justification code from `header-chain` crate

Mostly compiles, having issues with std/test feature flags across crates.

* Move some code around

* Move justification tests to integration testing crate

* Add `test-utils` crate

* Remove tests and test-helper module from justification code

* Use `test-utils` in Substrate bridge pallet tests

* Remove `sp-keyring` related code from `pallet-substrate-bridge`

* Remove `helpers` module from `pallet-substrate-bridge`

* Add some documentation

* Add more documentation

* Fix typo

Co-authored-by: Tomasz Drwięga <[email protected]>

Co-authored-by: Tomasz Drwięga <[email protected]>

* Update `sp-io` dependency

* Rename Trait to Config

* RustFmt

* Bump `sp-io` again

* Use new frame_system weight types in Rialto and Millau runtimes

* Update test Runtimes to use new weight types

* Bump `sp-io` again

* Update to not-the latest first.

* Update benchmarks.

* Another Trai.

* Move new weight types into runtime primitive crates

This allows us to check limits for extrinsics from other parts
of the codebase without pulling in the entire chain runtime.

* Remove leftover comments

* Move new functions to a better location

* Small formatting fixes

* Add actual documentation to new weight config types

* Decrease maximum block weight of Millau chain

* Decreease maximum block length of Millau chain

Co-authored-by: Tomasz Drwięga <[email protected]>

* parse substrate message proof

* unfinalized_header

* extract ChainBase to bp-runtime

* post-merge fixes

* cargo fmt --all

* compilation fixes

* reexport BlockNumberOf, HashOf, HeaderOf

* Remove the Substrate primitives crate

The types here were only used in one place, the pallet itself. If other
components start using these types we can considering moving them back
into a standalone crate.

* Start trying to integrate justification module

* Make Substrate blocks configurable in Pallet

* WIP: Try and generalize justification test helpers

* Fix tests which use "real" justifications

* Put common test helpers alongside mock code

* Use common helper for creating headers

* Remove usage of UintAuthorityId

This change favours the use of the Ed25519Keyring authorities
in order to keep things consistent with the tests.

* Add documentation around config trait types

* Make test header, hash, and number types consistent

* Update modules/substrate/src/verifier.rs

Co-authored-by: Svyatoslav Nikolsky <[email protected]>

* Update modules/substrate/src/lib.rs

Co-authored-by: Tomasz Drwięga <[email protected]>

* Update modules/substrate/Cargo.toml

Co-authored-by: Svyatoslav Nikolsky <[email protected]>

* Derive `RuntimeDebug` instead of `Debug`

* Add `Paramter` as a trait constraint on config types

Since we use these types as part of the dispatchable functions
we should explicitly require this.

* Enforce that hasher output matches expected hash type

* Accept headers over indexes when making test justifications

* Check that authority sets are valid

* Make Clippy happy

* Apply correct Clippy fix

* Move justification code into primitives module

* Use new module in verifier code

* Add primitives module for Substrate test helpers

* WIP

* Move justification generation into test_helpers

* Revert commits which move `justification` into primitives

This reverts commit 03a381f0

.

Co-authored-by: Svyatoslav Nikolsky <[email protected]>
Co-authored-by: Tomasz Drwięga <[email protected]>

* Change script to update versions.

* Bump versions.

* Address remainders.

* cargo fmt --all

* Fix tests.

* Whitelist BlueOak license

* Fix benchmarks?

* Add pallet template from Substrate Dev Hub

* Clean up un-needed stuff from template

* Sketch out dispatchable interface

* Introduce notion of finality chain

* Add dependencies which were removed during a rebase

* Sketch out idea for finality header-chain pallet

* Sketch out ChainVerifier trait

* Add storage parameter to verifier

* Write out some things I think I need for finality verification

* Add some pseudocode for marking finalized headers

* Remove parity_scale_codec duplicate

* Move verification logic into pallet

I've been struggling with getting the generic types between the storage and verifier
traits to play nice with each other. As a way to continue making progress I'm moving
everything to the pallet. This way I hope to make progress towards a functional
pallet.

* Start doing verification around authority set changes

* Remove commented BridgeStorage and ChainVerifier traits

* Create Substrate bridge primitives crate

* Add logic for updating scheduled authority sets

* Introduce notion of imported headers

* Implement basic header ancestry checker

* Add mock runtime for tests

* Add testing boilerplate

* Add some storage read/write sanity tests

* Add some basic header import tests

* Add tests for ancestry proofs

* Create helper for changing authority sets

* Fix authority set test

Fixes a problem with how the scheduled change was counted as well as
a SCALE encoding issue

* Correctly check for scheduled change digests

There's no guarantee that the consensus digest item will be the last
one in a header, which is how it was previously being checked.

Thanks to Andre for pointing me to the Grandpa code that does this.

* Mark imported headers as finalized when appropriate

When a header that finalizes a chain of headers is succesfully imported
we also want to mark its ancestors as finalized.

* Add helper for writing test headers

* Add test helper for scheduling authority set changes

* Bump Substrate pallet and primitives to rc6

* Remove Millau verifier implementation

* Add some doc comments

* Remove some needless returns

* Make Clippy happy

* Split block import from finalization

* Make tests compile again

* Add test for finalizing header after importing children

* Create a test stub for importing future justifications

* Start adding genesis config

* Reject justifications from future

We should only be accepting justifications for the header
which enacted the current authority set. Any ancestors of
that header which require a justification can be imported
but they must not be finalized.

* Add explanation to some `expect()` calls

* Start adding GenesisConfig

* Plug genesis config into runtime

* Remove tests module

* Check for overflow when updating authority sets

* Make verifier take ownership of headers during import

* Only store best finalized header hash

Removed the need to store the whole header, since we store
it was part of the ImportedHeaders structure anyways

* Add some helpers to ImportedHeader

* Update ancestry checker to work with ImportedHeaders

* Update ancestry tests to use ImportedHeaders

* Update import tests to use ImportedHeaders

* Clean up some of the test helpers

* Remove stray dbg!

* Add doc comments throughout

* Remove runtime related code

* Fix Clippy warnings

* Remove trait bound on ImportedHeader struct

* Simplify checks in GenesisConfig

* Rename `get_header_by_hash()`

* Alias `parity_scale_codec` to `codec`

* Reword Verifier documentation

* Missed codec rename in tests

* Split ImportError into FinalizationError

* Remove ChainVerifier trait

This trait was a remenant of the original design, and it is not required
at the moment. Something like it should be added back in the future to
ensure that other chains which conform to this interface can be used
by higher-level bridge applications.

* Fix the verifier tests so they compile

* Implement Deref for ImportedHeader

* Get rid of `new` methods for some Substrate primitives

* Ensure that a child header's number follows its parent's

* Prevent ancestry checker from aimlessly traversing to genesis

If an ancestor which was newer than the child header we were checking we
would walk all the way to genesis before realizing that we weren't related.
This commit fixes that.

* Remove redundant clones

* Ensure that old headers are not finalized

Prevents a panic where if the header being imported and `best_finalized`
were the same header the ancestry checker would return an empty list. We
had made an assumption that the list would always be populated, and if this
didn't hold we would end up panicking.

* Disallow imports at same height as `best_finalized`

* Fix Clippy warnings

* Make NextScheduledChange optional

* Rework how scheduled authority set changes are enacted

We now require a justification for headers which _enact_ changes
instead of those which _schedule_ changes. A few changes had to
be made to accomodate this, such as changing when we check for
scheduled change logs in incoming headers.

* Update documentation for Substrate Primitives

* Clarify why we skip header in requires_justification check

* Add description to assert! call

* Fix formatting within macros

* Remove unused dependencies from runtime

* Remove expect call in GenesisConfig

* Turn FinalityProof into a struct

* Add some inline TODOs for follow up PRs

* Remove test which enacted multiple changes

This should be added back at some later point in time, but right now
the code doesn't allow for this behaviour.

* Use `contains_key` when checking for header

This is better than using `get().is_some()` since we skip
decoding the storage value

* Use initial hash when updating best_finalized

* Add better checks around enacting scheduled changes

* Rename finality related functions

* Appease Clippy

* remove queueing from message-lane

* also remove queueing from RPCs

* another trace

* new clippy

* make message-lane Event generic

* cargo fmt --all

* Update modules/message-lane/src/lib.rs

Co-authored-by: Hernando Castano <[email protected]>

Co-authored-by: Hernando Castano <[email protected]>

* initial commit of DummyOrdered (aka message-lane) pallet

* API for relay

* cargo fmt --all

* some clippy + no_std

* more clippy + no_std

* inbound lane tests

* outbound lane tests

* cargo fmt --all

* prune old messages whenever outbound lane is updated

* do not care about MessageNonce overflow

* cargo fmt --all

* update crate docs

* MaxHeadersToPruneAtOnce -> MaxMessagesToPruneAtOnce

* MessageAction -> MessageResult

* cargo fmt --all

* fire MessageAccepted + MessagesDelivered

* confirm message processing

* cargo fmt --all

* clippy

* cargo fmt again

* Update modules/message-lane/src/lib.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update modules/message-lane/src/lib.rs

Co-authored-by: Hernando Castano <[email protected]>

* use crate::*

* cargo fmt --all

* Storage -> S

* Update modules/message-lane/src/outbound_lane.rs

Co-authored-by: Hernando Castano <[email protected]>

* add method doc

* Update modules/message-lane/src/inbound_lane.rs

Co-authored-by: Hernando Castano <[email protected]>

* added detailed module docs

* Update modules/message-lane/src/lib.rs

Co-authored-by: Tomasz Drwięga <[email protected]>

* updated OnMessageReceived docs

* prune only when new message is sent

* removed #![warn(missing_docs)]

* fixed merge with overlapped PR

Co-authored-by: Hernando Castano <[email protected]>
Co-authored-by: Tomasz Drwięga <[email protected]>