Commit graph

25 commits

Author SHA1 Message Date
Luke Parker
e4e4245ee3
One Round DKG (#589)
* Upstream GBP, divisor, circuit abstraction, and EC gadgets from FCMP++

* Initial eVRF implementation

Not quite done yet. It needs to communicate the resulting points and proofs to
extract them from the Pedersen Commitments in order to return those, and then
be tested.

* Add the openings of the PCs to the eVRF as necessary

* Add implementation of secq256k1

* Make DKG Encryption a bit more flexible

No longer requires the use of an EncryptionKeyMessage, and allows pre-defined
keys for encryption.

* Make NUM_BITS an argument for the field macro

* Have the eVRF take a Zeroizing private key

* Initial eVRF-based DKG

* Add embedwards25519 curve

* Inline the eVRF into the DKG library

Due to how we're handling share encryption, we'd either need two circuits or to
dedicate this circuit to the DKG. The latter makes sense at this time.

* Add documentation to the eVRF-based DKG

* Add paragraph claiming robustness

* Update to the new eVRF proof

* Finish routing the eVRF functionality

Still needs errors and serialization, along with a few other TODOs.

* Add initial eVRF DKG test

* Improve eVRF DKG

Updates how we calculcate verification shares, improves performance when
extracting multiple sets of keys, and adds more to the test for it.

* Start using a proper error for the eVRF DKG

* Resolve various TODOs

Supports recovering multiple key shares from the eVRF DKG.

Inlines two loops to save 2**16 iterations.

Adds support for creating a constant time representation of scalars < NUM_BITS.

* Ban zero ECDH keys, document non-zero requirements

* Implement eVRF traits, all the way up to the DKG, for secp256k1/ed25519

* Add Ristretto eVRF trait impls

* Support participating multiple times in the eVRF DKG

* Only participate once per key, not once per key share

* Rewrite processor key-gen around the eVRF DKG

Still a WIP.

* Finish routing the new key gen in the processor

Doesn't touch the tests, coordinator, nor Substrate yet.
`cargo +nightly fmt && cargo +nightly-2024-07-01 clippy --all-features -p serai-processor`
does pass.

* Deduplicate and better document in processor key_gen

* Update serai-processor tests to the new key gen

* Correct amount of yx coefficients, get processor key gen test to pass

* Add embedded elliptic curve keys to Substrate

* Update processor key gen tests to the eVRF DKG

* Have set_keys take signature_participants, not removed_participants

Now no one is removed from the DKG. Only `t` people publish the key however.

Uses a BitVec for an efficient encoding of the participants.

* Update the coordinator binary for the new DKG

This does not yet update any tests.

* Add sensible Debug to key_gen::[Processor, Coordinator]Message

* Have the DKG explicitly declare how to interpolate its shares

Removes the hack for MuSig where we multiply keys by the inverse of their
lagrange interpolation factor.

* Replace Interpolation::None with Interpolation::Constant

Allows the MuSig DKG to keep the secret share as the original private key,
enabling deriving FROST nonces consistently regardless of the MuSig context.

* Get coordinator tests to pass

* Update spec to the new DKG

* Get clippy to pass across the repo

* cargo machete

* Add an extra sleep to ensure expected ordering of `Participation`s

* Update orchestration

* Remove bad panic in coordinator

It expected ConfirmationShare to be n-of-n, not t-of-n.

* Improve documentation on  functions

* Update TX size limit

We now no longer have to support the ridiculous case of having 49 DKG
participations within a 101-of-150 DKG. It does remain quite high due to
needing to _sign_ so many times. It'd may be optimal for parties with multiple
key shares to independently send their preprocesses/shares (despite the
overhead that'll cause with signatures and the transaction structure).

* Correct error in the Processor spec document

* Update a few comments in the validator-sets pallet

* Send/Recv Participation one at a time

Sending all, then attempting to receive all in an expected order, wasn't working
even with notable delays between sending messages. This points to the mempool
not working as expected...

* Correct ThresholdKeys serialization in modular-frost test

* Updating existing TX size limit test for the new DKG parameters

* Increase time allowed for the DKG on the GH CI

* Correct construction of signature_participants in serai-client tests

Fault identified by akil.

* Further contextualize DkgConfirmer by ValidatorSet

Caught by a safety check we wouldn't reuse preprocesses across messages. That
raises the question of we were prior reusing preprocesses (reusing keys)?
Except that'd have caused a variety of signing failures (suggesting we had some
staggered timing avoiding it in practice but yes, this was possible in theory).

* Add necessary calls to set_embedded_elliptic_curve_key in coordinator set rotation tests

* Correct shimmed setting of a secq256k1 key

* cargo fmt

* Don't use `[0; 32]` for the embedded keys in the coordinator rotation test

The key_gen function expects the random values already decided.

* Big-endian secq256k1 scalars

Also restores the prior, safer, Encryption::register function.
2024-09-19 21:43:26 -04:00
Luke Parker
9af111b4aa
Rust 1.79, cargo update 2024-06-13 15:57:08 -04:00
Luke Parker
a41329c027
Update clippy now that redundant imports has been reverted 2024-04-23 04:31:27 -04:00
Luke Parker
ea3af28139
Add workspace lints 2023-12-17 00:04:47 -05:00
Luke Parker
11fdb6da1d
Coordinator Cleanup (#481)
* Move logic for evaluating if a cosign should occur to its own file

Cleans it up and makes it more robust.

* Have expected_next_batch return an error instead of retrying

While convenient to offer an error-free implementation, it potentially caused
very long lived lock acquisitions in handle_processor_message.

* Unify and clean DkgConfirmer and DkgRemoval

Does so via adding a new file for the common code, SigningProtocol.

Modifies from_cache to return the preprocess with the machine, as there's no
reason not to. Also removes an unused Result around the type.

Clarifies the security around deterministic nonces, removing them for
saved-to-disk cached preprocesses. The cached preprocesses are encrypted as the
DB is not a proper secret store.

Moves arguments always present in the protocol from function arguments into the
struct itself.

Removes the horribly ugly code in DkgRemoval, fixing multiple issues present
with it which would cause it to fail on use.

* Set SeraiBlockNumber in cosign.rs as it's used by the cosigning protocol

* Remove unnecessary Clone from lambdas in coordinator

* Remove the EventDb from Tributary scanner

We used per-Transaction DB TXNs so on error, we don't have to rescan the entire
block yet only the rest of it. We prevented scanning multiple transactions by
tracking which we already had.

This is over-engineered and not worth it.

* Implement borsh for HasEvents, removing the manual encoding

* Merge DkgConfirmer and DkgRemoval into signing_protocol.rs

Fixes a bug in DkgConfirmer which would cause it to improperly handle indexes
if any validator had multiple key shares.

* Strictly type DataSpecification's Label

* Correct threshold_i_map_to_keys_and_musig_i_map

It didn't include the participant's own index and accordingly was offset.

* Create TributaryBlockHandler

This struct contains all variables prior passed to handle_block and stops them
from being passed around again and again.

This also ensures fatal_slash is only called while handling a block, as needed
as it expects to operate under perfect consensus.

* Inline accumulate, store confirmation nonces with shares

Inlining accumulate makes sense due to the amount of data accumulate needed to
be passed.

Storing confirmation nonces with shares ensures that both are available or
neither. Prior, one could be yet the other may not have been (requiring an
assert in runtime to ensure we didn't bungle it somehow).

* Create helper functions for handling DkgRemoval/SubstrateSign/Sign Tributary TXs

* Move Label into SignData

All of our transactions which use SignData end up with the same common usage
pattern for Label, justifying this.

Removes 3 transactions, explicitly de-duplicating their handlers.

* Remove CurrentlyCompletingKeyPair for the non-contextual DkgKeyPair

* Remove the manual read/write for TributarySpec for borsh

This struct doesn't have any optimizations booned by the manual impl. Using
borsh reduces our scope.

* Use temporary variables to further minimize LoC in tributary handler

* Remove usage of tuples for non-trivial Tributary transactions

* Remove serde from dkg

serde could be used to deserialize intenrally inconsistent objects which could
lead to panics or faults.

The BorshDeserialize derives have been replaced with a manual implementation
which won't produce inconsistent objects.

* Abstract Future generics using new trait definitions in coordinator

* Move published_signed_transaction to tributary/mod.rs to reduce the size of main.rs

* Split coordinator/src/tributary/mod.rs into spec.rs and transaction.rs
2023-12-10 20:21:44 -05:00
Luke Parker
b296be8515
Replace bincode with borsh (#452)
* Add SignalsConfig to chain_spec

* Correct multiexp feature flagging for rand_core std

* Remove bincode for borsh

Replaces a non-canonical encoding with a canonical encoding which additionally
should be faster.

Also fixes an issue where we used bincode in transcripts where it cannot be
trusted.

This ended up fixing a myriad of other bugs observed, unfortunately.
Accordingly, it either has to be merged or the bug fixes from it must be ported
to a new PR.

* Make serde optional, minimize usage

* Make borsh an optional dependency of substrate/ crates

* Remove unused dependencies

* Use [u8; 64] where possible in the processor messages

* Correct borsh feature flagging
2023-11-25 04:01:11 -05:00
Luke Parker
05dc474cb3
Correct std feature-flagging
If a crate has std set, it should enable std for all dependencies in order to
let them properly select which algorithms to use. Some crates fallback to
slower/worse algorithms on no-std.

Also more aggressively sets default-features = false leading to a *10%*
reduction in the amount of crates coordinator builds.
2023-10-31 07:44:02 -04:00
Luke Parker
dd523b22c2
Correct transcript minimum version requirements 2023-08-08 18:32:13 -04:00
Luke Parker
fa406c507f
Update crypto/ package versions
On a branch while bitcoin-serai wraps up its audit.
2023-08-08 18:19:01 -04:00
Luke Parker
38ad1d4bc4
Add msrv definitions to common and crypto
This will effectively add msrv protections to the entire project as almost
everything grabs from these.

Doesn't add msrv to coins as coins/bitcoin is still frozen.

Doesn't add msrv to services since cargo msrv doesn't play nice with anything
importing the runtime.
2023-08-02 14:17:57 -04:00
Luke Parker
47f8766da6
Use proper messages for ValidatorSets/InInstructions pallet
Provides a DST, and associated metadata as beneficial.

Also utilizes MuSig's context to session-bind. Since set_keys_messages also
binds to set, this is semi-redundant, yet that's appreciated.
2023-05-13 04:40:16 -04:00
Luke Parker
227176e4b8
Correct various no_std definitions 2023-05-13 04:03:56 -04:00
Luke Parker
84c2d73093
Do the minimal amount of work for dkg to compile under no-std
The Substrate runtime requires access to the MuSig key aggregation function.

\#279 related.
2023-05-12 23:25:17 -04:00
Luke Parker
5765d1d278
Update to May's nightly
Doesn't use the PR due to the needed changes.
2023-05-01 04:58:50 -04:00
Luke Parker
952cf280c2
Bump crate versions 2023-03-20 20:34:41 -04:00
Luke Parker
0d4b66dc2a
Bump package versions 2023-03-16 19:29:22 -04:00
Luke Parker
e08adcc1ac
Have Ciphersuite re-export Group 2023-03-07 03:46:16 -05:00
Luke Parker
1a99629a4a
Add feature-gated serde support for Participant/ThresholdParams
These don't have secret data yet sometimes have value to be communicated.
2023-03-07 03:13:55 -05:00
Luke Parker
0e8c55e050
Update and remove unused dependencies 2023-03-07 03:06:46 -05:00
Luke Parker
c37cc0b4e2
Update Zeroize pin to ^1.5 from 1.5 2023-03-07 02:29:59 -05:00
Luke Parker
da8e7e73e0
Re-organize testing strategy and document Ciphersuite::hash_to_F. 2022-12-24 17:08:22 -05:00
Luke Parker
13977f6287
Clean and document the DKG library's encryption
Encryption used to be inlined into FROST. When writing the documentation, I
realized it was decently hard to review. It also was antagonistic to other
hosted DKG algorithms by not allowing code re-use.

Encryption is now a standalone module, providing clear boundaries and
reusability.

Additionally, the DKG protocol itself used to use the ciphersuite's specified
hash function (with an HKDF to prevent length extension attacks). Now,
RecommendedTranscript is used to achieve much more robust transcripting and
remove the HKDF dependency. This does add Blake2 into all consumers yet is
preferred for its security properties and ease of review.
2022-12-07 17:30:42 -05:00
Luke Parker
84de427d72
Fix https://github.com/serai-dex/serai/issues/150 2022-11-10 22:35:09 -05:00
Luke Parker
8de465af87
Have Transcript::append_message take in AsRef<[u8]>, not &[u8]
Simplifies calling it.
2022-11-05 18:43:36 -04:00
Luke Parker
2379855b31
Create a dedicated crate for the DKG (#141)
* Add dkg crate

* Remove F_len and G_len

They're generally no longer used.

* Replace hash_to_vec with a provided method around associated type H: Digest

Part of trying to minimize this trait so it can be moved elsewhere. Vec, 
which isn't std, may have been a blocker.

* Encrypt secret shares within the FROST library

Reduces requirements on callers in order to be correct.

* Update usage of Zeroize within FROST

* Inline functions in key_gen

There was no reason to have them separated as they were. sign probably 
has the same statement available, yet that isn't the focus right now.

* Add a ciphersuite package which provides hash_to_F

* Set the Ciphersuite version to something valid

* Have ed448 export Scalar/FieldElement/Point at the top level

* Move FROST over to Ciphersuite

* Correct usage of ff in ciphersuite

* Correct documentation handling

* Move Schnorr signatures to their own crate

* Remove unused feature from schnorr

* Fix Schnorr tests

* Split DKG into a separate crate

* Add serialize to Commitments and SecretShare

Helper for buf = vec![]; .write(buf).unwrap(); buf

* Move FROST over to the new dkg crate

* Update Monero lib to latest FROST

* Correct ethereum's usage of features

* Add serialize to GeneratorProof

* Add serialize helper function to FROST

* Rename AddendumSerialize to WriteAddendum

* Update processor

* Slight fix to processor
2022-10-29 03:54:42 -05:00