Consolidate XOnlyPubKey lookup hack

The places where we need to lookup information for a XOnlyPubKey
currently implement a hack which makes both serializations of the full
pubkey in order to try the CKeyIDs for the lookup functions. Instead of
duplicating this everywhere it is needed, we can consolidate the CKeyID
generation into a function, and then have wrappers around GetPubKey,
GetKey, and GetKeyOrigin which takes the XOnlyPubKey, retrieves all of
the CKeyIDs (using the new GetKeyIDs() function in XOnlyPubKey), and
tries their respective underlying lookup function.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/pubkey.h b/src/pubkey.h
index eec34a89c2..861a2cf500 100644
--- a/src/pubkey.h
+++ b/src/pubkey.h
@@ -267,6 +267,11 @@ public:
     /** Construct a Taproot tweaked output point with this point as internal key. */
     std::optional<std::pair<XOnlyPubKey, bool>> CreateTapTweak(const uint256* merkle_root) const;
 
+    /** Returns a list of CKeyIDs for the CPubKeys that could have been used to create this XOnlyPubKey.
+     * This is needed for key lookups since keys are indexed by CKeyID.
+     */
+    std::vector<CKeyID> GetKeyIDs() const;
+
     const unsigned char& operator[](int pos) const { return *(m_keydata.begin() + pos); }
     const unsigned char* data() const { return m_keydata.begin(); }
     static constexpr size_t size() { return decltype(m_keydata)::size(); }