librustzcash/zcash_client_backend/CHANGELOG.md

# Changelog
All notable changes to this library will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this library adheres to Rust's notion of
[Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [Unreleased]
### Added
- A new feature flag, `transparent-inputs` is now available for use in 
  compilation of `zcash_primitives`, `zcash_client_backend`, and 
  `zcash_client_sqlite`. This flag must be enabled to provide access to the
  functionality which enables the receiving and spending of transparent funds.
- A new `data_api::wallet::spend` method has been added, which is
  intended to supersede the `data_api::wallet::create_spend_to_address`
  method. This new method now constructs transactions via interpretation
  of a `zcash_client_backend::zip321::TransactionRequest` value. 
  This facilitates the implementation of ZIP 321 support in wallets and
  provides substantially greater flexibility in transaction creation.
- A new `data_api::wallet::shield_transparent_funds` method has been added
  to facilitate the automatic shielding of transparent funds received
  by the wallet.
- `zcash_client_backend::data_api::WalletRead::get_transaction` has been added
  to provide access to decoded transaction data.
- `zcash_client_backend::data_api::WalletRead::get_all_nullifiers` has been
  added. This method provides access to all Sapling nullifiers, including
  for notes that have been previously marked spent.
- `zcash_client_backend::data_api::WalletRead::get_unspent_transparent_outputs`
  has been added under the `transparent-inputs` feature flag to provide access
  to received transparent UTXOs.
- A new `zcash_client_backend::encoding::AddressCodec` trait has been added
  to facilitate address encoding. This new API should be considered unstable
  and is likely to be removed or changed in an upcoming release.
- `zcash_client_backend::encoding::encode_payment_address` has been added.
  This API should be considered unstable.
- `zcash_client_backend::encoding::encode_transparent_address` has been added.
  This API should be considered unstable.

### Changed
- MSRV is now 1.51.0.
- Bumped dependencies to `ff 0.11`, `group 0.11`, `bls12_381 0.6`, `jubjub 0.8`.
- `epk: jubjub::ExtendedPoint` has been replaced by
  `ephemeral_key: zcash_note_encryption::EphemeralKeyBytes` in various places:
  - `zcash_client_backend::wallet::WalletShieldedOutput`: the `epk` field has
    been replaced by `ephemeral_key`.
  - `zcash_client_backend::proto::compact_formats::CompactOutput`: the `epk`
    method has been replaced by `ephemeral_key`.

- Renamed the following in `zcash_client_backend::data_api` to use lower-case
  abbreviations (matching Rust naming conventions):
  - `error::Error::InvalidExtSK` to `Error::InvalidExtSk`
  - `testing::MockWalletDB` to `testing::MockWalletDb`
- `data_api::WalletRead::get_target_and_anchor_heights` now takes 
  a `min_confirmations` argument that is used to compute an upper bound on the
  anchor height being returned; this had previously been hardcoded to
  `data_api::wallet::ANCHOR_OFFSET`.
- `data_api::WalletRead::get_spendable_notes` has been renamed to 
  `get_spendable_sapling_notes`
- `data_api::WalletRead::select_spendable_notes` has been renamed to 
  `select_spendable_sapling_notes`
- The `zcash_client_backend::data_api::SentTransaction` type has been
  substantially modified to accommodate handling of transparent
  inputs.
- `data_api::WalletWrite::store_received_tx` has been renamed to 
  `store_decrypted_tx` and it now takes an explicit list of 
  `(AccountId, Nullifier)` pairs that allows the library to 
  provide quick access to previously decrypted nullifiers.
- An `Error::MemoForbidden` error has been added to the 
  `data_api::error::Error` enum to report the condition where a
  memo was specified to be sent to a transparent recipient.
- The hardcoded `data_api::wallet::ANCHOR_OFFSET` constant has been removed.
- `zcash_client_backend::keys::spending_key` has been moved to the
  `zcash_client_backend::keys::sapling` module.
- Two new types, `UnifiedSpendingKey` and `UnifiedFullViewingKey` 
  have been added to the `zcash_client_backend::keys` module. These 
  types should be considered unstable as they are likely to be changed
  and/or extracted into a different crate in a future release.
- A `zcash_client_backend::wallet::WalletTransparentOutput` type
  has been added under the `transparent-inputs` feature flag in support
  of autoshielding functionality.
- `zcash_client_backend::zip321::MemoError` has been renamed and 
  expanded into a more comprehensive `Zip321Error` type, and 
  functions in hthe `zip321` module have been updated to use
  this unified error type.
- The `zcash_client_backend::wallet::AccountId` type has been moved
  to the `zcash_primitives::zip32` module.

## [0.5.0] - 2021-03-26
### Added
- `zcash_client_backend::address::RecipientAddress`
- `zcash_client_backend::data_api` module, containing the Data Access API.
- `zcash_client_backend::wallet`:
  - `AccountId`
  - `SpendableNote`
  - `OvkPolicy`
- `zcash_client_backend::welding_rig::ScanningKey` trait, representing a key
  which can be used for trial decryption of outputs, and optionally nullifier
  computation. This trait is implemented for
  `zcash_primitives::zip32:ExtendedFullViewingKey` and
  `zcash_primitives::primitives::SaplingIvk`.
- First alpha of TZE support, behind the `zfuture` feature flag.

### Changed
- MSRV is now 1.47.0.
- `epk` fields and return values were changed from a `jubjub::SubgroupPoint` to
  a `jubjub::ExtendedPoint`, to match the change to the `zcash_primitives`
  decryption APIs:
  - `zcash_client_backend::proto::compact_formats::CompactOutput::epk()`
  - The `epk` field of `zcash_client_backend::wallet::WalletShieldedOutput`.
- `zcash_client_backend::decrypt`:
  - `decrypt_transaction` now takes a variable with type
    `P: zcash_primitives::consensus::Parameters`.
  - The `memo` field of `DecryptedOutput` now has type `MemoBytes`.
- `zcash_client_backend::wallet`:
  - The `nf` property of `WalletShieldedSpend` now has the type `Nullifier`.
  - The `account` property of `WalletShieldedSpend` and `WalletShieldedOutput`
    now has the type `AccountId`.
- `zcash_client_backend::welding_rig`:
  - `scan_block` now takes `&[(AccountId, K: ScanningKey)]`, instead of a
    slice of extended full viewing keys with implicit account IDs.
  - The `nullifiers` argument to `scan_block` now has the type
    `&[(AccountId, Nullifier)]`.

### Removed
- `zcash_client_backend::constants` module (its sub-modules have been moved into
  `zcash_primitives::constants`, and more generally replaced by the new methods
  on the `zcash_primitives::consensus::Parameters` trait).

## [0.4.0] - 2020-09-09
### Changed
- MSRV is now 1.44.1.
- Bumped dependencies to `ff 0.8`, `group 0.8`, `bls12_381 0.3.1`,
  `jubjub 0.5.1`, `protobuf 2.15`.

## [0.3.0] - 2020-08-24
TBD

## [0.2.0] - 2020-03-13
TBD

## [0.1.0] - 2019-10-08
Initial release.