* 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
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.
Doesn't fully utilize ec's hash2curve module as k256 Scalar doesn't have
FromOkm for some reason. The previously present bigint reduction is
preserved.
Updates ff/group to 0.12.
Premised on https://github.com/cfrg/draft-irtf-cfrg-frost/pull/205 being
merged, as while this Ed25519 is vector compliant, it's technically not
spec compliant due to that conflict.
Saves ~8% during FROST key gen, even with dropping a vartime for a
constant time (as needed to be secure), as the new batch verifier is
used where batch verification previously wasn't. The new multiexp API
itself also offered a very slight performance boost, which may solely be
a measurement error.
Handles most of https://github.com/serai-dex/serai/issues/10. The blame
function isn't binary searched nor randomly sorted yet.
