Commit Graph

15 Commits

Author SHA1 Message Date
Luke Parker
cbceaff678 Create dedicated message structures for FROST messages (#140)
* Create message types for FROST key gen

Taking in reader borrows absolutely wasn't feasible. Now, proper types
which can be read (and then passed directly, without a mutable borrow)
exist for key_gen. sign coming next.

* Move FROST signing to messages, not Readers/Writers/Vec<u8>

Also takes the nonce handling code and makes a dedicated file for it, 
aiming to resolve complex types and make the code more legible by 
replacing its previously inlined state.

* clippy

* Update FROST tests

* read_signature_share

* Update the Monero library to the new FROST packages

* Update processor to latest FROST

* Tweaks to terminology and documentation
2022-10-25 23:17:25 -05:00
Luke Parker
a0a54eb0de Update to FROST v11
Ensures random functions never return zero. This, combined with a check 
commitments aren't 0, causes no serialized elements to be 0.

Also directly reads their vectors.
2022-10-13 00:38:36 -04:00
Luke Parker
ca091a5f04 Expand and correct documentation 2022-09-29 05:25:29 -04:00
Luke Parker
081b9a1975 FROST Ed448 (#107)
* Theoretical ed448 impl

* Fixes

* Basic tests

* More efficient scalarmul

Precomputes a table to minimize additions required.

* Add a torsion test

* Split into a constant and variable time backend

The variable time one is still far too slow, at 53s for the tests (~5s a 
scalarmul). It should be usable as a PoC though.

* Rename unsafe Ed448

It's not only unworthy of the Serai branding and deserves more clarity
in the name.

* Add wide reduction to ed448

* Add Zeroize to Ed448

* Rename Ed448 group.rs to point.rs

* Minor lint to FROST

* Ed448 ciphersuite with 8032 test vector

* Macro out the backend fields

* Slight efficiency improvement to point decompression

* Disable the multiexp test in FROST for Ed448

* fmt + clippy ed448

* Fix an infinite loop in the constant time ed448 backend

* Add b"chal" to the 8032 context string for Ed448

Successfully tests against proposed vectors for the FROST IETF draft.

* Fix fmt and clippy

* Use a tabled pow algorithm in ed448's const backend

* Slight tweaks to variable time backend

Stop from_repr(MODULUS) from passing.

* Use extended points

Almost two orders of magnitude faster.

* Efficient ed448 doubling

* Remove the variable time backend

With the recent performance improvements, the constant time backend is 
now 4x faster than the variable time backend was. While the variable 
time backend remains much faster, and the constant time backend is still 
slow compared to other libraries, it's sufficiently performant now.

The FROST test, which runs a series of multiexps over the curve, does 
take 218.26s while Ristretto takes 1 and secp256k1 takes 4.57s.

While 50x slower than secp256k1 is horrible, it's ~1.5 orders of 
magntiude, which is close enough to the desire stated in 
https://github.com/serai-dex/serai/issues/108 to meet it.

Largely makes this library safe to use.

* Correct constants in ed448

* Rename unsafe-ed448 to minimal-ed448

Enables all FROST tests against it.

* No longer require the hazmat feature to use ed448

* Remove extraneous as_refs
2022-08-29 02:32:59 -05:00
Luke Parker
a8a00598e4 Update to FROST v8 2022-08-26 05:59:43 -04:00
Luke Parker
280fc441a7 Lint FROST
Corrects ertrors introduced a couple commits ago as well.
2022-08-13 08:50:59 -04:00
Luke Parker
885d816309 Use a non-constant generator in FROST 2022-08-13 08:50:59 -04:00
Luke Parker
a423c23c1e Use zeroize instead of 0-sets 2022-08-12 01:14:13 -04:00
Luke Parker
797be71eb3 Utilize zeroize (#76)
* Apply Zeroize to nonces used in Bulletproofs

Also makes bit decomposition constant time for a given amount of 
outputs.

* Fix nonce reuse for single-signer CLSAG

* Attach Zeroize to most structures in Monero, and ZOnDrop to anything with private data

* Zeroize private keys and nonces

* Merge prepare_outputs and prepare_transactions

* Ensure CLSAG is constant time

* Pass by borrow where needed, bug fixes

The past few commitments have been one in-progress chunk which I've 
broken up as best read.

* Add Zeroize to FROST structs

Still needs to zeroize internally, yet next step. Not quite as 
aggressive as Monero, partially due to the limitations of HashMaps, 
partially due to less concern about metadata, yet does still delete a 
few smaller items of metadata (group key, context string...).

* Remove Zeroize from most Monero multisig structs

These structs largely didn't have private data, just fields with private 
data, yet those fields implemented ZeroizeOnDrop making them already 
covered. While there is still traces of the transaction left in RAM, 
fully purging that was never the intent.

* Use Zeroize within dleq

bitvec doesn't offer Zeroize, so a manual zeroing has been implemented.

* Use Zeroize for random_nonce

It isn't perfect, due to the inability to zeroize the digest, and due to 
kp256 requiring a few transformations. It does the best it can though.

Does move the per-curve random_nonce to a provided one, which is allowed 
as of https://github.com/cfrg/draft-irtf-cfrg-frost/pull/231.

* Use Zeroize on FROST keygen/signing

* Zeroize constant time multiexp.

* Correct when FROST keygen zeroizes

* Move the FROST keys Arc into FrostKeys

Reduces amount of instances in memory.

* Manually implement Debug for FrostCore to not leak the secret share

* Misc bug fixes

* clippy + multiexp test bug fixes

* Correct FROST key gen share summation

It leaked our own share for ourself.

* Fix cross-group DLEq tests
2022-08-03 03:25:18 -05:00
Luke Parker
e67033a207 Apply an initial set of rustfmt rules 2022-07-16 15:16:30 -05:00
Luke Parker
6cc8ce840e Move FROST to Read
Fixes https://github.com/serai-dex/serai/issues/33 and 
https://github.com/serai-dex/serai/issues/35. Also fixes a few potential 
panics/DoS AFAICT.
2022-07-13 02:38:29 -04:00
Luke Parker
133c1222ad Remove C::F_len, C::G_len for F_len<C> and G_len<C>
Relies on the ff/group API, instead of the custom Curve type.

Also removes GENERATOR_TABLE, only used by dalek, as we should provide 
our own API for that over ff/group instead. This slows down the FROST 
tests, under debug, by about 0.2-0.3s. Ed25519 and Ristretto together 
take ~2.15 seconds now.
2022-06-30 18:46:18 -04:00
Luke Parker
7890827a48 Implement variable-sized windows into multiexp
Closes https://github.com/serai-dex/serai/issues/17 by using the 
PrimeFieldBits API to do so.

Should greatly speed up small batches, along with batches in the 
hundreds. Saves almost a full second on the cross-group DLEq proof.
2022-06-30 09:30:24 -04:00
Luke Parker
3de7a76051 Use GroupEncoding instead of Curve's from_slice/to_bytes
Increases usage of standardization while expanding dalek_ff_group.

Closes https://github.com/serai-dex/serai/issues/26 by moving 
dfg::EdwardsPoint to only be for the prime subgroup.
2022-06-28 01:25:26 -04:00
Luke Parker
60254a0171 Reorganize FROST's handling of curves 2022-06-24 19:47:19 -04:00