rust-bitcoin

Rearrange impls and traits for types

At the moment, there are a handful of different orderings used for
traits + impl blocks on the types in crypto keys.

Unify trait + impl ordering to impl -> FromStr -> TryFrom -> From ->
LowerHex -> Display -> Debug.

Add From<Infallible> to all error types

As has been decided in bitcoin, all error types should have a
From<Infallible> impl to aid in possible usage with generics.

Bump old bitcoin version to 0.32.9 in fuzz

p2p: Error on invalid FeeRate in FeeFilter decode

The FeeFilterDecoder currently saturates invalid fee rate values (those
outside 0..=u32::MAX) to FeeRate::MAX. This prevents the type from
round-tripping and causes problems with checksum calculations in the
V1NetworkMessage. Instead, invalid fee rates should fail to decode and
the range of valid fee rates should be changed to 0..Amount::MAX_MONEY,
as it is in Core.

p2p: Error on decode for addresses > 512 bytes

The AddrV2Decoder decodes the address type and the byte blob using
an ArrayDecoder + ByteVecDecoder. In the old version, a byte blob with
more than 512 bytes would throw an error, whilst the new version
successfully decodes it to an unknown address type.

Add check for address_bytes blob length > 512 bytes and throw error to
match old behaviour.

Adjust encodable fuzz target for known differences

The encodable fuzzing target should ignore known differences between the
old and new encoders/decoders. Due to various limitations with error
types and such, some known differences are not accounted for yet.

Add ignores for transaction decoder errors with known differences.
Adjust ignores for AddrV2Messages for service flags limit.

taproot-primitives: Remove hashes/arbitrary

The hashes crate does not have an arbitrary feature, and it the
unreleased feature is not used in this crate, so there's no reason to
attempt to enable it when the taproot-primitives crate arbitrary is
enabled.

p2p: change example to use configurable magic param

The example does not currently work as documented outside of regtest.

p2p: Wrap V1MessageHeaderDecoderError with V1NetworkMessage Header err

The V1NetworkMessageDecoderErrorInner has a Header error variant with
no internal information. This makes it less useful to decode a
V1NetworkMessage with the V1NetworkMessageDecoder than a
V1MessageHeaderDecoder in the case of an error. In order that users can
still retrieve meaningful error information, the header's error should
be wrapped by the Header error variant.

Add internal V1MessageHeaderDecoderError for
V1NetworkMessageDecoderErrorInner::Header variant.

p2p: Use V1MessageHeaderDecoder in V1NetworkMessageDecoder

The V1NetworkMessageDecoder decodes the header fields at the start of
the decoding process using a manually defined Decoder4. Since the
header fields that it decodes are exactly equivalent to the existing
encoding of the V1MessageHeader, the decoder for the header should be
used. This also provides an opportunity to wrap the header decoder
error to provide more information to the user than the current error
does.

Replace manual Decoder4 header_decoder with V1MessageHeaderDecoder in
V1NetworkMessageDecoder.

p2p: Use parsed types in ReadingPayload state

The ReadingPayload state in the V1NetworkMessageDecoder holds byte
arrays that are parsed later during the end() call. While this possibly
improves performance in an error case, it prevents efficient usage of
the V1MessageHeaderDecoder for parsing the header, complicating types.

Replace magic_bytes and payload_len_bytes with magic and length and use
Magic and u32 parsed types instead of [u8; 4] arrays.

Adjust encodable fuzz target for known differences

The encodable fuzzing target should ignore known differences between the
old and new encoders/decoders. Due to various limitations with error
types and such, some known differences are not accounted for yet.

Add ignores for decoder errors with known differences between 0.32 and
new decoders.

skip rustfmt for `software_sha256d_64`

hashes: use the optimized scalar in sha256d_64 fallback

we get up to ~7% speedup with the new optimized scalar

hashes: Add scalar SHA256d for 64-byte input

add the three transforms for sha256(sha256(64_bytes)) without any
SIMD intrinsics, as a fallback for platforms without SHA-NI, AVX2,
or SSE4.1 support

fmt: Apply rustfmt across workspace

crypto: use constant-time equality for Poly1305 tags

Currently, the `decrypt` method uses the standard `==` operator for tag verification, which is vulnerable to timing attacks

### Changes
- Introduced a helper function `constant_time_eq` that iterates through the entire 16-byte tag regardless of where a mismatch occurs as constant-time alternative.

This change ensures that the decryption process is secure against side-channel timing leaks.

Fixes #6122

Add with_compressedness to LegacyPublicKey

At present, to convert a compressed LegacyPublicKey to an uncompressed
copy, a user must either to use from_secp_uncompressed(key.to_inner())
or roundtrip serialize-deserialize. Neither of these are ideal. To
avoid users touching the secp types directly, we can copy the pattern
used for parity in XOnlyPublicKey's with_parity.

Introduce with_compressedness method on LegacyPublicKey to set
compressedness.

crypto: Remove with_serialized from LegacyPublicKey

The with_serialized method on LegacyPublicKey has been used for
serialising the legacy public key in an optionally compressed form
without allocating a vec. With the introduction of the
SerialisedLegacyPublicKey type, the to_bytes() method can now trivially
replace this method with a simpler interface.

Replace all uses of with_serialized with to_bytes and remove method
from LegacyPublicKey.

crypto: Move taproot errors into submodule

Now that the taproot module in crypto is publicly visible, it should
be update to follow the patterns of other crates in the workspace
regarding the use of error submodules.

Move error types to error submodule and re-export.

crypto: Fix lint errors in crypto::taproot

Following the move to crypto, the stricter lint requirements now
trigger various problems with the module that should be fixed.

Fix all lint errors in the crypto::taproot module.

Move taproot signatures to crypto

As part of the move of types to crypto, the taproot signatures should
also be moved to the crypto crate.

Move taproot module to crypto and re-export signatures and errors in
bitcoin.

Remove io dependency from crypto taproot

The taproot module in bitcoin's crypto holds only the Signature and
SerializedSignature types. In order to retain the lack of io dep in
crypto, the io based methods on these types should be removed, as they
were on the corresponding ecdsa signature types.

Remove Signature::serialize_to_writer and SerializedSignature::write_to
methods.

Update API files

Ignore mutants for the decoder helper method which wraps default

Also updates existing rules from trait renames.