wallet: implement IsKeyActive() in scriptpubkeyman

This new method returns true if the given CScript key is derived
from the SPKM. For Legacy that means checking the hd_seed_id in the
key's metadata.

Also patches PKDescriptor to return associated public keys in
MakeScripts()

Github-Pull: #27216
Rebased-From: f39957f5deec87d141e995a3bc90cc54e2d0ccbf

src/script/descriptor.cpp

@@ -772,8 +772,11 @@ class PKDescriptor final : public DescriptorImpl
 private:
     const bool m_xonly;
 protected:
-    std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, Span<const CScript>, FlatSigningProvider&) const override
+    std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, Span<const CScript>, FlatSigningProvider& out) const override
     {
+        CKeyID id = keys[0].GetID();
+        out.pubkeys.emplace(id, keys[0]);
+
         if (m_xonly) {
             CScript script = CScript() << ToByteVector(XOnlyPubKey(keys[0])) << OP_CHECKSIG;
             return Vector(std::move(script));

src/wallet/scriptpubkeyman.cpp

@@ -395,6 +395,23 @@ std::vector<WalletDestination> LegacyScriptPubKeyMan::MarkUnusedAddresses(const
     return result;
 }
 
+bool LegacyScriptPubKeyMan::IsKeyActive(const CScript& script) const
+{
+    LOCK(cs_KeyStore);
+
+    if (!IsMine(script)) return false; // Not in the keystore at all
+
+    for (const auto& key_id : GetAffectedKeys(script, *this)) {
+        const auto it = mapKeyMetadata.find(key_id);
+        if (it == mapKeyMetadata.end()) return false; // This key must be really old
+
+        if (!it->second.hd_seed_id.IsNull() && it->second.hd_seed_id == m_hd_chain.seed_id) return true;
+    }
+
+    // Imported or dumped for a new keypool
+    return false;
+}
+
 void LegacyScriptPubKeyMan::UpgradeKeyMetadata()
 {
     LOCK(cs_KeyStore);

src/wallet/scriptpubkeyman.h

@@ -204,6 +204,9 @@ public:
      */
     virtual std::vector<WalletDestination> MarkUnusedAddresses(const CScript& script) { return {}; }
 
+    /* Determines if address is derived from active key manager */
+    virtual bool IsKeyActive(const CScript& script) const = 0;
+
     /** Sets up the key generation stuff, i.e. generates new HD seeds and sets them as active.
       * Returns false if already setup or setup fails, true if setup is successful
       * Set force=true to make it re-setup if already setup, used for upgrades
@@ -393,6 +396,8 @@ public:
 
     std::vector<WalletDestination> MarkUnusedAddresses(const CScript& script) override;
 
+    [[nodiscard]] bool IsKeyActive(const CScript& script) const override;
+
     //! Upgrade stored CKeyMetadata objects to store key origin info as KeyOriginInfo
     void UpgradeKeyMetadata();
 
@@ -627,6 +632,8 @@ public:
 
     std::vector<WalletDestination> MarkUnusedAddresses(const CScript& script) override;
 
+    [[nodiscard]] bool IsKeyActive(const CScript& script) const override { return IsMine(script); }
+
     bool IsHDEnabled() const override;
 
     //! Setup descriptors based on the given CExtkey