Implement Taproot validation (BIP 341)

This includes key path spending and script path spending, but not the
Tapscript execution implementation (leaf 0xc0 remains unemcumbered in
this commit).

Includes constants for various aspects of the consensus rules suggested
by Jeremy Rubin.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/pubkey.h b/src/pubkey.h
index 1a818037d1..0f784b86e4 100644
--- a/src/pubkey.h
+++ b/src/pubkey.h
@@ -221,8 +221,10 @@ public:
      * sigbytes must be exactly 64 bytes.
      */
     bool VerifySchnorr(const uint256& msg, Span<const unsigned char> sigbytes) const;
+    bool CheckPayToContract(const XOnlyPubKey& base, const uint256& hash, bool parity) const;
 
     const unsigned char& operator[](int pos) const { return *(m_keydata.begin() + pos); }
+    const unsigned char* data() const { return m_keydata.begin(); }
     size_t size() const { return m_keydata.size(); }
 };