coinstats: Fix hash_serialized2 calculation

The legacy serialization was vulnerable to maleation and is fixed by
adopting the same serialization procedure as was already in use for
MuHash.

This also includes necessary test fixes where the hash_serialized2 was
hardcoded as well as correction of the regtest chainparams.

Co-authored-by: Sebastian Falbesoner <sebastian.falbesoner@gmail.com>

3 files changed, 8 insertions, 6 deletions

diff --git a/test/functional/feature_assumeutxo.py b/test/functional/feature_assumeutxo.py
index 2765509f84..9c265649d5 100755
--- a/test/functional/feature_assumeutxo.py
+++ b/test/functional/feature_assumeutxo.py
@@ -94,8 +94,10 @@ class AssumeutxoTest(BitcoinTestFramework):
 
         self.log.info("  - snapshot file with alternated UTXO data")
         cases = [
-            [b"\xff" * 32, 0, "29926acf3ac81f908cf4f22515713ca541c08bb0f0ef1b2c3443a007134d69b8"], # wrong outpoint hash
-            [(1).to_bytes(4, "little"), 32, "798266c2e1f9a98fe5ce61f5951cbf47130743f3764cf3cbc254be129142cf9d"], # wrong outpoint index
+            [b"\xff" * 32, 0, "05030e506678f2eca8d624ffed97090ab3beadad1b51ee6e5985ba91c5720e37"], # wrong outpoint hash
+            [(1).to_bytes(4, "little"), 32, "7d29cfe2c1e242bc6f103878bb70cfffa8b4dac20dbd001ff6ce24b7de2d2399"], # wrong outpoint index
+            [b"\x81", 36, "f03939a195531f96d5dff983e294a1af62af86049fa7a19a7627246f237c03f1"], # wrong coin code VARINT((coinbase ? 1 : 0) | (height << 1))
+            [b"\x83", 36, "e4577da84590fb288c0f7967e89575e1b0aa46624669640f6f5dfef028d39930"], # another wrong coin code
         ]
 
         for content, offset, wrong_hash in cases:
@@ -103,7 +105,7 @@ class AssumeutxoTest(BitcoinTestFramework):
                 f.write(valid_snapshot_contents[:(32 + 8 + offset)])
                 f.write(content)
                 f.write(valid_snapshot_contents[(32 + 8 + offset + len(content)):])
-            expected_error(log_msg=f"[snapshot] bad snapshot content hash: expected ef45ccdca5898b6c2145e4581d2b88c56564dd389e4bd75a1aaf6961d3edd3c0, got {wrong_hash}")
+            expected_error(log_msg=f"[snapshot] bad snapshot content hash: expected 61d9c2b29a2571a5fe285fe2d8554f91f93309666fc9b8223ee96338de25ff53, got {wrong_hash}")
 
     def run_test(self):
         """
@@ -150,7 +152,7 @@ class AssumeutxoTest(BitcoinTestFramework):
 
         assert_equal(
             dump_output['txoutset_hash'],
-            'ef45ccdca5898b6c2145e4581d2b88c56564dd389e4bd75a1aaf6961d3edd3c0')
+            '61d9c2b29a2571a5fe285fe2d8554f91f93309666fc9b8223ee96338de25ff53')
         assert_equal(dump_output['nchaintx'], 300)
         assert_equal(n0.getblockchaininfo()["blocks"], SNAPSHOT_BASE_HEIGHT)
 
diff --git a/test/functional/feature_utxo_set_hash.py b/test/functional/feature_utxo_set_hash.py
index 0f510ced89..49c01eee1d 100755
--- a/test/functional/feature_utxo_set_hash.py
+++ b/test/functional/feature_utxo_set_hash.py
@@ -69,7 +69,7 @@ class UTXOSetHashTest(BitcoinTestFramework):
         assert_equal(finalized[::-1].hex(), node_muhash)
 
         self.log.info("Test deterministic UTXO set hash results")
-        assert_equal(node.gettxoutsetinfo()['hash_serialized_2'], "f9aa4fb5ffd10489b9a6994e70ccf1de8a8bfa2d5f201d9857332e9954b0855d")
+        assert_equal(node.gettxoutsetinfo()['hash_serialized_2'], "d1c7fec1c0623f6793839878cbe2a531eb968b50b27edd6e2a57077a5aed6094")
         assert_equal(node.gettxoutsetinfo("muhash")['muhash'], "d1725b2fe3ef43e55aa4907480aea98d406fc9e0bf8f60169e2305f1fbf5961b")
 
     def run_test(self):
diff --git a/test/functional/rpc_dumptxoutset.py b/test/functional/rpc_dumptxoutset.py
index f378878181..1ea6cf52d1 100755
--- a/test/functional/rpc_dumptxoutset.py
+++ b/test/functional/rpc_dumptxoutset.py
@@ -46,7 +46,7 @@ class DumptxoutsetTest(BitcoinTestFramework):
             'b1bacb602eacf5fbc9a7c2ef6eeb0d229c04e98bdf0c2ea5929012cd0eae3830')
 
         assert_equal(
-            out['txoutset_hash'], '1f7e3befd45dc13ae198dfbb22869a9c5c4196f8e9ef9735831af1288033f890')
+            out['txoutset_hash'], 'a0b7baa3bf5ccbd3279728f230d7ca0c44a76e9923fca8f32dbfd08d65ea496a')
         assert_equal(out['nchaintx'], 101)
 
         # Specifying a path to an existing or invalid file will fail.