Commit Graph

255 Commits

Author SHA1 Message Date
Deirdre Connolly f9de91716c Add docstrings for sighash 2020-10-20 11:16:22 -04:00
Jane Lusby 855f9b5bcb
Implement MVP of NonFinalizedState and integrate it with the state service (#1101)
* implement most of the chain functions
* implement fork
* fix outpoint handling in Chain struct
* update expect for work
* split utxo into two sets
* update the Chain definition
* remove allow attribute in zebra-state/lib.rs
* merge ChainSet type into MemoryState
* Add error messages to asserts
* export proptest impls for use in downstream crates
* add testjob for disabled feature in zebra-chain
* try to fix github actions syntax
* add module doc comment
* update RFC for utxos
* add missing header
* working proptest for Chain
* propagate back results over channel
* Start updating RFC to match changes
* implement queued block pruning
* and now it syncs wooo!
* remove empty modules
* setup config for proptests
* re-enable missing_docs lint
* update RFC to match changes in impl
* add documentation
* use more explicit variable names
2020-10-08 13:07:32 +10:00
Jane Lusby 86ed13060f
Add tests for `Chain` implementation (#1093)
* Begin work on RFC5 implementation

* I think this is necessary

* holy shit supertrait implemented via subtrait

* implement most of the chain functions

* change to slightly better name

* implement fork

* fix outpoint handling in Chain struct

* update expect for work

* resolve review comment

* split utxo into two sets

* update the Chain definition

* just a little more

* update comment

* Apply suggestions from code review

Co-authored-by: teor <teor@riseup.net>

* apply changes from code review

* remove allow attribute in zebra-state/lib.rs

* Update zebra-state/src/memory_state.rs

Co-authored-by: teor <teor@riseup.net>

* merge ChainSet type into MemoryState

* rename state impl types

* Add error messages to asserts

* checkpoint so I can split off arbitrary changes into a PR

* export proptest impls for use in downstream crates

* add testjob for disabled feature in zebra-chain

* run rustfmt

* try to fix github actions syntax

* differentiate name

* prove that github action tests zebra-chain build without features

* revert change from last commit now that test is running

* remove accidentally introduced newline

* checkpoint

* add module doc comment

* update RFC for utxos

* add missing header

* working proptest for Chain

* apply change from chain impl PR

* setup config for proptests

* Update zebra-chain/src/block/arbitrary.rs

Co-authored-by: teor <teor@riseup.net>

* run rustfmt

Co-authored-by: teor <teor@riseup.net>
2020-10-02 15:51:51 -07:00
Jane Lusby 0b4e974c9e
export proptest impls for use in downstream crates (#1092)
* export proptest impls for use in downstream crates

* add testjob for disabled feature in zebra-chain

* run rustfmt

* try to fix github actions syntax

* differentiate name

* prove that github action tests zebra-chain build without features

* revert change from last commit now that test is running

* remove accidentally introduced newline

* Update .github/workflows/ci.yml

Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>

Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
2020-09-23 18:52:52 -07:00
Jane Lusby 6744f415d2
Implement sighash (#870)
* Implement sighash

* move sighash logic to a separate module

* start filling in more of the alg

* start setting up a test case

* make the test useful

* Iter transaction inputs

* better error message for expect

* add support for zip243 sighash

* ohey first testvector is passing, yayyy

* pass the second testvector

* add last testvector

* move a use statement

* use common deserialization code for amount everywhere

* cleanup attributes

* bring in fixed preimage

* fix discrepancy with spec

* always deserialize as a signed value

* Update zebra-chain/src/transaction/sighash.rs

* update unreachable statements

* add serialization impls for nonnegative amounts

* Apply suggestions from code review

* document sighash fn

* tweek docs

* fix mistake in translation for zip243

* consistent error messages

* reorder because i like it more that way

* document more panics

* Update zebra-chain/src/amount.rs

* Add comment regarding the serialization of spend descriptions in sighash

Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
2020-09-05 19:31:11 -04:00
Alfredo Garcia 454e75e7c0
Rename old references to BlockHeaderHash and BlockHeight (#1002)
* rename some references

* Apply suggestions from code review

Co-authored-by: Deirdre Connolly <durumcrustulum@gmail.com>
Co-authored-by: teor <teor@riseup.net>

Co-authored-by: Deirdre Connolly <durumcrustulum@gmail.com>
Co-authored-by: teor <teor@riseup.net>
2020-09-04 15:40:48 -07:00
Henry de Valence e96a472099 chain: impl Display for {block, transaction}::Hash
Also add a Display/FromStr round-trip proptest.
2020-09-04 17:08:41 -04:00
Henry de Valence 0a1878d9c3 chain: add docs about transaction and block hashes. 2020-09-04 17:08:41 -04:00
Henry de Valence 2a50298b2e chain: add transaction hash test. 2020-09-04 17:08:41 -04:00
Henry de Valence ca4a5ce30c chain: add Transaction::hash() method.
This makes Transaction and Block have a consistent API.
2020-09-04 17:08:41 -04:00
Jane Lusby 96c8809348
Implement Inventory Tracking RFC (#963)
* Add .cargo to the gitignore file

* Implement Inventory Tracking RFC

* checkpoint

* wire together the inventory registry

* add comment documenting condition

* make inventory registry optional
2020-09-01 14:28:54 -07:00
Henry de Valence ebdceb5197 chain: rename TransactionHash to transaction::Hash 2020-08-17 11:46:34 -07:00
Henry de Valence d49d3d2b30 chain: tweak docs for JoinSplitData, ShieldedData 2020-08-17 11:46:34 -07:00
Henry de Valence 5c176d2f96 chain: move JoinSplit to sprout 2020-08-17 11:46:34 -07:00
Henry de Valence 1fc859d0c5 chain: move Spend, Output into sapling
The ShieldedData container for the spend and output descriptions of a
transaction does *not* move, because it's encoding transaction
structure.  A good sign that this is the right factoring is that the
transaction module now only needs to pull in sapling::{Spend, Output}
and not all the internals.
2020-08-17 11:46:34 -07:00
Henry de Valence d945cd28e8 chain: move Transparent{Input,Output} to transparent
Also bring the `Script` type there too.
2020-08-17 11:46:34 -07:00
Henry de Valence 103b663c40 chain: rename BlockHeight to block::Height 2020-08-17 11:46:34 -07:00
Henry de Valence e8f923ec86 chain: move Memo into transaction 2020-08-17 11:46:34 -07:00
Henry de Valence 312c66264a chain: extract sprout code into sprout module. 2020-08-17 11:46:34 -07:00
Henry de Valence e06f59ee21 chain: extract sapling code to sapling module 2020-08-17 11:46:34 -07:00
Henry de Valence c5a8cb0c91 chain: create primitives module.
This contains definitions of primitive types used in other structures
and re-exports of component libraries.
2020-08-17 11:46:34 -07:00
Henry de Valence dad6340cd3 chain: move BlockHeight into block 2020-08-17 11:46:34 -07:00
Henry de Valence 5f71bcd0d1 chain: move LockTime into transaction 2020-08-17 11:46:34 -07:00
Henry de Valence 8e9a239687 chain: clean transaction tests module.
This moves the transaction strategies to `arbitrary`, to live with the
other strategy impls (`Arbitrary` is just a default type-associated
strategy), splits the proptests into a new `prop` module, and splits the
test vector checks into a `vector`s module.

This ensures that we keep code in leaf modules and only have
organization (use statements) in non-leaf modules.
2020-08-17 11:46:34 -07:00
Henry de Valence a35604aef3 chain: move amount to a top-level module. 2020-08-17 11:46:34 -07:00
Henry de Valence cee7d0b8eb chain: move serde_helpers into serialization. 2020-08-17 11:46:34 -07:00
Henry de Valence b36fe8f937 chain: move sha256d to serialization module.
This extracts the SHA256d code from being split across two modules and puts it
in one module, under serialization.

The code is unchanged except for three deleted tests:

* `sha256d_flush` in `sha256d_writer` (not a meaningful test);
* `transactionhash_debug` (constructs an invalid transaction hash, and the
  behavior is tested in the next test);
* `decode_state_debug` (we do not need to test the Debug output of
  DecodeState);
2020-08-17 11:46:34 -07:00
Deirdre Connolly 616d82faaf Use the jubjub::AffinePoint in the canonical, encoded little-endian byte form in
Pedersen tests

Keeps the librustzcash test vectors with their big-endian byte order
as comments, for greppability.
2020-08-14 02:04:12 -04:00
Deirdre Connolly a2c9011e06 Impl ZcashDeserialize for jubjub::Fq, use in transaction deserialization 2020-08-14 02:04:12 -04:00
Deirdre Connolly 437f40d3c8 Refine JoinSplit::anchor to be a sprout::NoteTreeRootHash type 2020-08-14 02:04:12 -04:00
Deirdre Connolly 5a5882700c Tidy JoinSplit nullifiers deserialization 2020-08-14 02:04:12 -04:00
Deirdre Connolly 6b13ce3e83 Add Sapling EphemeralPublicKey type that wraps jubjub::AffinePoint 2020-08-14 02:04:12 -04:00
Deirdre Connolly c8771ef620 Defer to From/Into [u8; 32] vs Zcash(De)Serialize for sprout::NoteCommitments 2020-08-14 02:04:12 -04:00
Deirdre Connolly 619afffa16 Use convenience Reader/Writer methods to only use From/Into for nullifer serialization
And thus remove duplicative Zcash(De)Serialization impls
2020-08-14 02:04:12 -04:00
Deirdre Connolly e8fdd0e1f3 Impl TryFrom for Commitments, call from impl ZcashDeserialize 2020-08-14 02:04:12 -04:00
Deirdre Connolly 5d13880461 Remove Zcash(De)Serialize impls for *Commitments 2020-08-14 02:04:12 -04:00
Deirdre Connolly b6385ca36f Move commitment types into commitments module
Docs, tidy
2020-08-14 02:04:12 -04:00
Deirdre Connolly dfb10ab10f Add NoteCommitment.extract_u() 2020-08-14 02:04:12 -04:00
Deirdre Connolly 33730a05cb Do not confuse a NoteCommitment for U(NoteCommitment) 2020-08-14 02:04:12 -04:00
Deirdre Connolly 0d618a3abf Start treestate module 2020-08-14 02:04:12 -04:00
Deirdre Connolly 2c285985c8 Move nullifiers to respective note modules, pull in existing types from keys 2020-08-14 02:04:12 -04:00
Henry de Valence f8a24f9c11
Rename script fields to lock/unlock scripts. (#866)
This is slightly clearer and more correct than the previous pk_script.
2020-08-10 11:49:38 -07:00
teor 41225660fb doc: The genesis coinbase is the same in every network 2020-07-23 03:46:24 -04:00
Henry de Valence 90ec2982bf docs: fix broken links 2020-07-22 17:55:52 -07:00
teor 1915634d2b
Check for bad heights or hashes in checkpoint lists (#639)
* Add MIN and MAX for BlockHeight and LockTime
* Remove duplicate test cases
* fix a comment about the minimum lock time

The minimum LockTime::Time is 5 November 1985 00:53:20 UTC, so the first
day that only contains valid times is 6 November 1985 (in all timezones).

Similarly, the maximum LockTime::Time is 7 February 2106 06::28::15 UTC,
so the last day that only contains valid times in all time zones is
5 February 2106.

* fix: Reject checkpoint lists with bad hashes or heights

Reject the all-zeroes hash, because it is the parent hash of the genesis
block, and should never appear in a checkpoint list.

Reject checkpoint heights that are greater than the maximum block
height.
2020-07-16 15:09:22 +10:00
Jane Lusby 0474a79669
Add cool helpers for using zcash_serialize / zcash_deserialize (#586)
Co-authored-by: Dimitris Apostolou <dimitris.apostolou@icloud.com>
2020-07-09 15:29:31 -04:00
Henry de Valence 8b72781fe1 deps: Update redjubjub to 0.2
Closes #606.
2020-07-09 15:20:23 -04:00
Alfredo Garcia d736355f9f
Add ZIP143 and ZIP243 test vectors (#585) 2020-07-03 09:45:40 +10:00
Jane Lusby 00e750654a
add nullifier types (#568)
* add nullifier types

* Apply suggestions from code review

Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>

* add zcash_deserialize impls

* Add docs

Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
2020-07-01 17:57:32 -07:00
Jane Lusby c216f5ca25
Refine type for MAC (#577) 2020-07-01 17:57:03 -07:00
Jane Lusby 8281b9040c
Start work on new Amount type (#554) 2020-07-01 16:31:30 -07:00
Jane Lusby 6cbb6d4574
consolidate arbitrary impls to one file in zebra-chain (#553)
* consolidate arbitrary impls to one file in zebra-chain

* move the ones I missed

* move test-vectors

Co-authored-by: Jane Lusby <jane@zfnd.org>
2020-06-30 14:23:38 -07:00
teor 719aa75581 chain: Add a comment about transaction sizes
We don't need to check transaction sizes yet, because we aren't
parsing or generating transactions outside of blocks.

Part of #483.
2020-06-24 18:22:36 +10:00
Henry de Valence 9ddcccdcb4 Update ed25519-zebra to 0.3 2020-06-16 00:42:25 -04:00
Henry de Valence a023ba9b16
Add serde bounds to zebra-chain structures. (#231) 2020-06-15 15:08:14 -07:00
Jane Lusby 9f802cd8dd Wrap Transaction in Arc 2020-06-06 18:13:17 -04:00
Deirdre Connolly b263489af6
Export ed25519 zebra (#445)
And use that one, and our similar redjubjub export, everywhere.

Fixes #405

* Move PRs to 'In Progress' column on project board when created
2020-06-06 18:10:32 -04:00
Jane Lusby 4a2d2a359c
add cargo fmt to ci (#403)
* add cargo fmt to ci

* rebase on main

* switch to stable

Co-authored-by: Jane Lusby <jane@zfnd.org>
2020-05-27 19:12:25 -07:00
Jane Lusby b6b35364f3 cleanup warnings throughout codebase 2020-05-27 15:42:29 -04:00
Kiminuo 6465689555 transaction/hash.rs: Add FromStr implementation (issue #299)
Co-authored-by: Deirdre Connolly <durumcrustulum@gmail.com>
2020-05-14 15:30:11 -04:00
Deirdre Connolly df7ed7ae81
Move note encryption types around (#362)
* Move around and dedupe note *Cipertext types

* Bump code coverage test timeout to 5 minutes

* Try uploading coverage to codecov.io
2020-04-19 14:45:25 -04:00
Deirdre Connolly 21eca164d8 Refine Output description ephemeral_key to jubjub::AffinePoint
And impl Arbitrary for Output to support better generation of those points in proptests.
2020-04-18 22:05:13 -04:00
Deirdre Connolly 7a4be955be Remove todo 2020-04-18 22:05:13 -04:00
Deirdre Connolly cdfcdc4751 Tidy imports 2020-04-18 04:40:31 -04:00
Deirdre Connolly 05ca1c0c8a Refine JoinSplit ephemeral keys to be x25519_dalek::PublicKey
Impls PartialEq and Eq and Arbitrary on JoinSplit because PublicKey
does not impl them and we can't do it directly.

Resolves #313
2020-04-13 15:32:04 -04:00
Deirdre Connolly 955a4ebc3c Rename SpendDescription to Spend, OutputDescription to Output 2020-04-09 17:17:21 -04:00
Henry de Valence 2d2603cf65 Add a CoinbaseData field, replacing Vec<u8>.
The CoinbaseData field can only be constructed by the transaction parser, so we
can ensure that a coinbase input is always serializable, as CoinbaseData
instances can't be constructed outside of the parser that maintains the data
size invariant.
2020-02-19 15:42:20 -05:00
Henry de Valence b443d7a4be Fix clippy lints. 2020-02-14 18:23:41 -05:00
Henry de Valence 44b299d15c Parse block heights in coinbase transactions.
BIP34, which is included in Zcash, encodes the block height into each
block by adding it into the unused BitcoinScript field of the block's
coinbase transaction.  However, this is done just by requiring that the
script pushes the block height onto the stack when it executes, and
there are multiple different ways to push data onto the stack in
BitcoinScript.  Also, the genesis block does not include the block
height, by accident.

Because we want to *parse* transactions into an algebraic data type that
encodes their structural properties, rather than allow possibly-invalid
data to float through the internals of our node, we want to extract the
block height upfront and store it separately from the rest of the
coinbase data, which is inert.  So the serialization code now contains
just enough logic to parse BitcoinScript-encoded block heights, and
special-case the encoding of the genesis block.

Elsewhere in the source code, the `LockTime` struct requires that we
must use block heights less than 500,000,000 (above which the number is
interpreted as a unix timestamp, not a height).  To unify invariants, we
ensure that the parsing logic works with block heights up to
500,000,000, even though these are unlikely to ever be used for Zcash.
2020-02-14 18:23:41 -05:00
Henry de Valence 4957567409 Represent coinbase inputs explicitly.
Coinbase inputs are handled differently from other inputs and have
different consensus rules, so they should be represented differently in
the source code.  This lets us discard extraneous details (for instance,
it's not necessary to maintain the all-zero hash) and specialize logic.
2020-02-14 18:23:41 -05:00
Henry de Valence 972d16518f Make ZcashSerialize infallible mod its Writer.
Closes #158.

As discussed on the issue, this makes it possible to safely serialize
data into hashes, and encourages serializable data to make illegal
states unrepresentable.
2020-02-05 19:48:43 -05:00
Henry de Valence f04f4f0b98 Apply clippy fixes 2020-02-05 12:42:32 -08:00
Deirdre Connolly 69164a6943 Add test for BlockHeaderHash::from(BlockHeader) 2020-02-04 18:04:53 -05:00
Deirdre Connolly 3ea4a6a9ab Move transaction test vectors around
Resolves #210
2020-02-04 18:04:53 -05:00
Deirdre Connolly ac3c31b1c2 Rearrange and tidy imports 2020-01-28 03:48:23 -05:00
Deirdre Connolly 157add149a Note that shielded_data::EncryptedCiphertext should move as part of note encryption work
Co-Authored-By: Henry de Valence <hdevalence@hdevalence.ca>
2020-01-28 03:48:23 -05:00
Deirdre Connolly 101f0a5c0a Remove commented out asserts in serialize
Co-Authored-By: Henry de Valence <hdevalence@hdevalence.ca>
2020-01-28 03:48:23 -05:00
Deirdre Connolly cdeaeaa3d6 Remove commented out asserts
Co-Authored-By: Henry de Valence <hdevalence@hdevalence.ca>
2020-01-28 03:48:23 -05:00
Deirdre Connolly 09e34f258f Note that joinsplit::EncryptedCiphertext structs should move as part of note encryption work
Co-Authored-By: Henry de Valence <hdevalence@hdevalence.ca>
2020-01-28 03:48:23 -05:00
Deirdre Connolly 283d06bb08 Add (de)serialization roundtrip proptext for shielded_data::(Encrypted,Out)Ciphertext 2020-01-28 03:48:23 -05:00
Deirdre Connolly 2df20b9e6c Add (de)serialization roundtrip proptext for joinsplit::EncryptedCiphertext 2020-01-28 03:48:23 -05:00
Deirdre Connolly a259a6b4b1 Add and use v4_strategy() 2020-01-28 03:48:23 -05:00
Deirdre Connolly a93e2db44b Add and use OutCiphertext
Instead of [u64; 10].
2020-01-28 03:48:23 -05:00
Deirdre Connolly 289f8ec9ca impl Arbitrary for SpendDescription and refine impl for ShieldedData 2020-01-28 03:48:23 -05:00
Deirdre Connolly f8781c3415 Refine Arbitrary impl for JoinSplitData<P> 2020-01-28 03:48:23 -05:00
Deirdre Connolly 100c5b15ec Impl Arbitrary for ShieldedData and derive it for other types
Wraps the construction of redjubjub Signature so we don't
need an explicit impl for it.
2020-01-28 03:48:23 -05:00
Deirdre Connolly 7632863454 Impl Arbitrary for JoinSplitData<P>
Wraps the construction of ed25519 PublicKeyBytes and Signature so we don't
need an explicit impl for ed25519 types.
2020-01-28 03:48:23 -05:00
Deirdre Connolly b47e886eed Add transaction v3 proptest strategy 2020-01-28 03:48:23 -05:00
Deirdre Connolly 9cbc60a2d7 Proptest v1 and v2 transaction variants 2020-01-28 03:48:23 -05:00
Deirdre Connolly 31b759a924 Update (de)serialization to use EncryptedCiphertext types 2020-01-28 03:48:23 -05:00
Deirdre Connolly ffd64d4b71 Add shielded_data::EncryptedCiphertext 2020-01-28 03:48:23 -05:00
Deirdre Connolly 95f3c61e53 Add joinsplit::EncryptedCiphertext and derive(Arbitrary) on JoinSplit* 2020-01-28 03:48:23 -05:00
Deirdre Connolly b0c0055915 Transaction::V1 round trip proptest 2020-01-28 03:48:23 -05:00
Deirdre Connolly dfb28b7854 Stubbing out an Arbitrary impl for variant V1 of the Transaction enum 2020-01-28 03:48:23 -05:00
Henry de Valence 60f3f35d89 Refine Ed25519 byte arrays to ed25519-zebra types. 2020-01-24 16:43:31 -05:00
Henry de Valence 2e04610be3 Fix doc errors (missing links, etc). 2020-01-24 13:38:23 -08:00
Henry de Valence 4d5c8c7940 Clarify Transaction docs to point to iterator methods.
Closes #191.
2020-01-24 13:38:23 -08:00
Henry de Valence 41021c65ad Implement transaction (de)serialization. 2019-12-31 02:46:39 -05:00
Henry de Valence 53cae4647e Make invalid ShieldedData unrepresentable.
ShieldedData objects must have at least one spend or output; using Either
ensures that at least one must be present.  This is similar to the
JoinSplitData case, but slightly more complicated: rather than enforcing that
one list has at least one element (which can be done as `(first, rest)`), here
we need to use Either.   This has the downside that it is possible to construct
multiple equivalent internal representations (choosing whether a spend or
output goes in the `first` slot), but this easily fixed with a custom PartialEq
implementation.
2019-12-31 02:46:39 -05:00
Henry de Valence 8ff4139c1f Use Groth16Proof in ShieldedData, not just JoinSplits. 2019-12-31 02:46:39 -05:00
Henry de Valence fa1e168fb5 Ensure that invalid JoinSplitDatas are unrepresentable.
All JoinSplitDatas must contain at least one JoinSplit.
2019-12-31 02:46:39 -05:00
Henry de Valence c26304d983 Correct an error in transaction modeling.
In the previous transaction modeling I defined the structs so that the number
of old and new commitments for a JoinSplit were variable, when in fact the
Sprout design fixes both to be 2.  So now they are hardcoded as 2 in the source
code as well.  This commit also fixes some missing `pub` fields on the
`JoinSplit` struct.
2019-12-31 02:46:39 -05:00
Henry de Valence 056127dc94 Copy a transaction test vector from librustzcash. 2019-12-31 02:46:39 -05:00
Henry de Valence 4315235d52 Use RedJubjub types in zebra-chain. (#142) 2019-12-12 14:23:19 -05:00
Henry de Valence c013895cd7 Update Transaction definition. (#105)
* Added a few more top-level fields for the Transaction struct

* Add a placeholder Script type.

This could alternately use bytes::Bytes to save some allocations
but I don't think this is important to get perfectly now.  In the future, we
will want to have all of the script handling code in the zebra-script crate,
but we will need to have a container type for an encoded script in zebra-chain,
because otherwise zebra-chain would depend on zebra-script and not the other
way around.

* Rename Transaction{Input,Output} -> Transparent{Input,Output}.

These are only *transparent* inputs and outputs, so by putting Transparent in
the name (instead of Transaction) it's more clear that a transaction's inputs
or outputs can also be shielded.

* Add a LockTime enum.

* First attempt at a Transaction enum.

This attempts to map the versioning and field presence rules into an ADT, so
that structurally invalid transactions (e.g., a BCTV14 proof in a Sapling
transaction) are unrepresentable.

* Update zebra-chain/src/transaction.rs

Co-Authored-By: Daira Hopwood <daira@jacaranda.org>

* Add fixme note on type refinement.

* Rename Transaction variants according to version.

* Split transaction.rs into submodules.

* Start filling in spend, output descriptions.

* Progress on JoinSplit data structures.

This has a lot of duplication and should really use generics to abstract over
Sprout-on-BCTV14 or Sprout-on-Groth16.

* Add data types for Bctv14 and Groth16 proofs.

This also adds a trait to abstract over them.

* Make JoinSplit descriptions generic over the proof system.

* Update zebra-chain/src/transaction/joinsplit.rs
2019-12-05 15:56:58 -05:00