Wallycore

- libsecp256k1-zkp: The internal libsecp256k1 library version has been updated
to fix a potential timing leak when compiling with clang v14 or later.
Although there are no known exploits at this time, users are encouraged to
update as soon as possible.
- descriptor_get_num_variants: Now returns 1 instead of 0 if no variants are
present. This allows iterating the variant from 0 to the number of variants
returned in order to generate all scripts/addresses.
- scriptpubkey_csv_2of3_then_2_from_bytes has been removed from the API.
- psbt: psbt_finalize now takes an extra flags parameter. The Java and Python
wrappers default this to zero for backwards compatibility.
- psbt: output_index, sequence, required_locktime and required_lockheight are
now returned as uint32_t values. Wrapped languages are not affected.

- witness_multisig_from_bytes: The length for the internally generated
scriptsig was not calculated correctly, and not checked after generation.
In rare cases where all signatures encode to the maximum DER signature
encoding, this may cause an invalid write/read of 1-2 bytes past an
allocated buffer. The severity of this depends on the users malloc
implementation, but all users are encouraged to upgrade to the latest
version. Note that the Jade and Bitbox02 hardware wallets and the Green
wallet apps are confirmed to *not* be affected by this issue.
- The old Javascript and cordova wrappers have been removed. Users should move
to the new JS wrappers which are significantly more functional.
- `WALLY_SEGWIT_ADDRESS_PUBKEY_MAX_LEN` was increased to account for future
segwit versions, in accordance with BIP 141. The previous value is available
as `WALLY_SEGWIT_V0_ADDRESS_PUBKEY_MAX_LEN`.

- Javascript: Add a new WASM-based JS + typescript wrapper for Node and
browsers. This now supports the entire wally API and builds to an npm module.
- Javascript: The old JS wrappers are now deprecated and will be removed
in the next release. Please report any issues with the replacement wrapper.
- psbt_extract now takes an extra flags parameter. The Java and Python
wrappers default this to zero for backwards compatibility.
- bip39_mnemonic_to_seed is no longer available for SWIG-wrapped languages.
Callers should use bip39_mnemonic_to_seed512 instead.
- Python: Remove support for Python 2.x.
- Python: The Python wrappers are now automatically generated. Please ensure
you thoroughly test your Python code after upgrading.
- Python: Some calls (e.g. bip39_mnemonic_to_seed512, aes, and aes_cbc) used
to take output buffers to fill and return the number of bytes written. These
calls now automatically create and fill thier buffer, returning it as the
only return value. The number of bytes written can be determined by using
len() on the returned output buffer.

- Support for PSET v0 (Elements) has been removed.
- PSBT: PSBT/PSET v2 support has been added. The ABI has changed slightly as a result.
Users will need to recompile their applications and change function names and
arguments in the cases listed below:
- PSBT_PROPRIETARY_TYPE has been renamed to WALLY_PSBT_PROPRIETARY_TYPE to respect
wallys namespace.
- psbt_init_alloc has changed its definition and now has a new flags argument.
Passing `WALLY_PSBT_INIT_PSET` to this function will create an Elements
PSET instead of a PSBT (version must be passed as 2 in this case).
- psbt_from_base64 and psbt_from_bytes now take an extra flags parameter. The
Java and Python wrappers default this to zero for backwards compatibility.
- psbt_add_input_at has been renamed to psbt_add_tx_input_at.
- psbt_add_output_at has been renamed to psbt_add_tx_output_at.
- wally_map initialization functions now take a verification function
as an extra parameter.
- wally_map_add_keypath_item has been renamed to wally_map_keypath_add.
This call must only be made on a keypath initialized map.
- The input and output variants wally_psbt_input_add_keypath_item and
wally_psbt_output_add_keypath_item have also been renamed to
wally_psbt_input_keypath_add and wally_psbt_output_keypath_add.
- New functions wally_map_keypath_bip32_init_alloc and
wally_map_keypath_public_key_init_alloc for initializing BIP32 and public key
keypath maps have been added.
- Note that PSET support for issuance and peg-in is incomplete at this time and
may contain bugs. Users are strongly advised to test their code thoroughly
if using these features.

- struct wally_operations has changed to hold the size of the struct
and has an additional member to allow overriding the lib secp context
used internally. Users must recompile their applications against this
version as a result (re-linking or simply upgrading the shared library
is insufficient).

- Build: Note that the secp256k1-zkp library is now a git submodule rather
than being directly checked in to the source tree. Run
`git submodule sync --recursive` then `git submodule update --init --recursive`
from the source tree in order to clone the secp source and build the library.
When you sync this change initially you may need to `rm -r src/secp256k1` then
`git checkout src/secp256k1` to remove any old files and achieve a clean
source tree.