refactor: Use type-safe assumeutxo hash

This avoids accidentally mixing it up with other hashes (like block
hashes).

src/chainparams.cpp

@@ -451,11 +451,11 @@ public:
         m_assumeutxo_data = MapAssumeutxo{
             {
                 110,
-                {uint256S("0x1ebbf5850204c0bdb15bf030f47c7fe91d45c44c712697e4509ba67adb01c618"), 110},
+                {AssumeutxoHash{uint256S("0x1ebbf5850204c0bdb15bf030f47c7fe91d45c44c712697e4509ba67adb01c618")}, 110},
             },
             {
                 210,
-                {uint256S("0x9c5ed99ef98544b34f8920b6d1802f72ac28ae6e2bd2bd4c316ff10c230df3f2"), 210},
+                {AssumeutxoHash{uint256S("0x9c5ed99ef98544b34f8920b6d1802f72ac28ae6e2bd2bd4c316ff10c230df3f2")}, 210},
             },
         };
 

src/chainparams.h

@@ -10,6 +10,7 @@
 #include <consensus/params.h>
 #include <primitives/block.h>
 #include <protocol.h>
+#include <util/hash_type.h>
 
 #include <memory>
 #include <vector>
@@ -25,6 +26,10 @@ struct CCheckpointData {
     }
 };
 
+struct AssumeutxoHash : public BaseHash<uint256> {
+    explicit AssumeutxoHash(const uint256& hash) : BaseHash(hash) {}
+};
+
 /**
  * Holds configuration for use during UTXO snapshot load and validation. The contents
  * here are security critical, since they dictate which UTXO snapshots are recognized
@@ -32,7 +37,7 @@ struct CCheckpointData {
  */
 struct AssumeutxoData {
     //! The expected hash of the deserialized UTXO set.
-    const uint256 hash_serialized;
+    const AssumeutxoHash hash_serialized;
 
     //! Used to populate the nChainTx value, which is used during BlockManager::LoadBlockIndex().
     //!

src/test/validation_tests.cpp

@@ -135,11 +135,11 @@ BOOST_AUTO_TEST_CASE(test_assumeutxo)
     }
 
     const auto out110 = *ExpectedAssumeutxo(110, *params);
-    BOOST_CHECK_EQUAL(out110.hash_serialized, uint256S("1ebbf5850204c0bdb15bf030f47c7fe91d45c44c712697e4509ba67adb01c618"));
+    BOOST_CHECK_EQUAL(out110.hash_serialized.ToString(), "1ebbf5850204c0bdb15bf030f47c7fe91d45c44c712697e4509ba67adb01c618");
     BOOST_CHECK_EQUAL(out110.nChainTx, (unsigned int)110);
 
     const auto out210 = *ExpectedAssumeutxo(210, *params);
-    BOOST_CHECK_EQUAL(out210.hash_serialized, uint256S("9c5ed99ef98544b34f8920b6d1802f72ac28ae6e2bd2bd4c316ff10c230df3f2"));
+    BOOST_CHECK_EQUAL(out210.hash_serialized.ToString(), "9c5ed99ef98544b34f8920b6d1802f72ac28ae6e2bd2bd4c316ff10c230df3f2");
     BOOST_CHECK_EQUAL(out210.nChainTx, (unsigned int)210);
 }
 

src/validation.cpp

@@ -4939,7 +4939,7 @@ bool ChainstateManager::PopulateAndValidateSnapshot(
 
     const AssumeutxoData& au_data = *maybe_au_data;
 
-    if (stats.hashSerialized != au_data.hash_serialized) {
+    if (AssumeutxoHash{stats.hashSerialized} != au_data.hash_serialized) {
         LogPrintf("[snapshot] bad snapshot content hash: expected %s, got %s\n",
             au_data.hash_serialized.ToString(), stats.hashSerialized.ToString());
         return false;