Merge bitcoin/bitcoin#28196: BIP324 connection support

db9888feec48c6220a2fcf92865503bbbdab02a4 net: detect wrong-network V1 talking to V2Transport (Pieter Wuille)
91e1ef8684997fb4b3e8b64ef3935a936445066b test: add unit tests for V2Transport (Pieter Wuille)
297c8889975a18258d6cc39b1ec1e94fed6630fb net: make V2Transport preallocate receive buffer space (Pieter Wuille)
3ffa5fb49ee4a6d9502aa957093bd94058630282 net: make V2Transport send uniformly random number garbage bytes (Pieter Wuille)
0be752d9f8ca27320bc3e82498c7640fabd7e8de net: add short message encoding/decoding support to V2Transport (Pieter Wuille)
8da8642062fa2c7aa2f49995b832c3d0897e37ed net: make V2Transport auto-detect incoming V1 and fall back to it (Pieter Wuille)
13a7f01557272db652b3f333af3f06af6897253f net: add V2Transport class with subset of BIP324 functionality (Pieter Wuille)
dc2d7eb810ef95b06620f334c198687579916435 crypto: Spanify EllSwiftPubKey constructor (Pieter Wuille)
5f4b2c6d79e81ee0445752ad558fcc17831f4b2f net: remove unused Transport::SetReceiveVersion (Pieter Wuille)
c3fad1f29df093e8fd03d70eb43f25ee9d531bf7 net: add have_next_message argument to Transport::GetBytesToSend() (Pieter Wuille)

Pull request description:

  This is part of #27634.

  This implements the BIP324 v2 transport (which implements all of what the BIP calls transport layer *and* application layer), though in a non-exposed way. It is tested through an extensive fuzz test, which verifies that v2 transports can talk to v2 transports, and v1 transports can talk to v2 transports, and a unit test that exercises a number of unusual scenarios. The transport is functionally complete, including:
  * Autodetection of incoming V1 connections.
  * Garbage, both sending and receiving.
  * Short message type IDs, both sending and receiving.
  * Ignore packets (receiving only, but tested in a unit test).
  * Session IDs are visible in `getpeerinfo` output (for manual comparison).

  Things that are not included, left for future PRs, are:
  * Actually using the v2 transport for connections.
  * Support for the `NODE_P2P_V2` service flag.
  * Retrying downgrade to V1 when attempted outbound V2 connections immediately fail.
  * P2P functional and unit tests

ACKs for top commit:
  naumenkogs:
    ACK db9888feec48c6220a2fcf92865503bbbdab02a4
  theStack:
    re-ACK db9888feec48c6220a2fcf92865503bbbdab02a4
  mzumsande:
    Code Review ACK db9888feec48c6220a2fcf92865503bbbdab02a4

Tree-SHA512: 8906ac1e733a99e1f31c9111055611f706d80bbfc2edf6a07fa6e47b21bb65baacd1ff17993cbbf588063b2f5ad30b3af674a50c7bc8e8ebf4671483a21bbfeb

1 files changed, 6 insertions, 0 deletions

diff --git a/src/pubkey.cpp b/src/pubkey.cpp
index 4866feed67..05808e4c22 100644
--- a/src/pubkey.cpp
+++ b/src/pubkey.cpp
@@ -336,6 +336,12 @@ bool CPubKey::Derive(CPubKey& pubkeyChild, ChainCode &ccChild, unsigned int nChi
     return true;
 }
 
+EllSwiftPubKey::EllSwiftPubKey(Span<const std::byte> ellswift) noexcept
+{
+    assert(ellswift.size() == SIZE);
+    std::copy(ellswift.begin(), ellswift.end(), m_pubkey.begin());
+}
+
 CPubKey EllSwiftPubKey::Decode() const
 {
     secp256k1_pubkey pubkey;