blockchain: enforce 10 block age for spending outputs

Some custom wallet code apparently ignores this, which causes users
of that code to be fingerprinted

src/cryptonote_config.h

@@ -163,6 +163,7 @@
 #define HF_VERSION_MIN_V2_COINBASE_TX           12
 #define HF_VERSION_SAME_MIXIN                   12
 #define HF_VERSION_REJECT_SIGS_IN_COINBASE      12
+#define HF_VERSION_ENFORCE_MIN_AGE              12
 
 #define PER_KB_FEE_QUANTIZATION_DECIMALS        8
 

src/cryptonote_core/blockchain.cpp

@@ -2982,6 +2982,9 @@ bool Blockchain::check_tx_inputs(transaction& tx, tx_verification_context &tvc,
   const auto waiter_guard = epee::misc_utils::create_scope_leave_handler([&]() { waiter.wait(&tpool); });
   int threads = tpool.get_max_concurrency();
 
+  uint64_t max_used_block_height = 0;
+  if (!pmax_used_block_height)
+    pmax_used_block_height = &max_used_block_height;
   for (const auto& txin : tx.vin)
   {
     // make sure output being spent is of type txin_to_key, rather than
@@ -3048,6 +3051,13 @@ bool Blockchain::check_tx_inputs(transaction& tx, tx_verification_context &tvc,
   if (tx.version == 1 && threads > 1)
     waiter.wait(&tpool);
 
+  // enforce min output age
+  if (hf_version >= HF_VERSION_ENFORCE_MIN_AGE)
+  {
+    CHECK_AND_ASSERT_MES(*pmax_used_block_height + CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE <= m_db->height(),
+        false, "Transaction spends at least one output which is too young");
+  }
+
   if (tx.version == 1)
   {
     if (threads > 1)

tests/core_tests/chaingen_main.cpp

@@ -208,6 +208,7 @@ int main(int argc, char* argv[])
     GENERATE_AND_PLAY(gen_rct_tx_pre_rct_increase_vin_and_fee);
     GENERATE_AND_PLAY(gen_rct_tx_pre_rct_altered_extra);
     GENERATE_AND_PLAY(gen_rct_tx_rct_altered_extra);
+    GENERATE_AND_PLAY(gen_rct_tx_uses_output_too_early);
 
     GENERATE_AND_PLAY(gen_multisig_tx_valid_22_1_2);
     GENERATE_AND_PLAY(gen_multisig_tx_valid_22_1_2_many_inputs);

tests/core_tests/rct.cpp

@@ -40,8 +40,8 @@ using namespace cryptonote;
 //----------------------------------------------------------------------------------------------------------------------
 // Tests
 
-bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& events,
+bool gen_rct_tx_validation_base::generate_with_full(std::vector<test_event_entry>& events,
-    const int *out_idx, int mixin, uint64_t amount_paid, bool valid,
+    const int *out_idx, int mixin, uint64_t amount_paid, size_t second_rewind, uint8_t last_version, const rct::RCTConfig &rct_config, bool valid,
     const std::function<void(std::vector<tx_source_entry> &sources, std::vector<tx_destination_entry> &destinations)> &pre_tx,
     const std::function<void(transaction &tx)> &post_tx) const
 {
@@ -151,13 +151,13 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
 
   // rewind
   {
-    for (size_t i = 0; i < CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW; ++i)
+    for (size_t i = 0; i < second_rewind; ++i)
     {
       cryptonote::block blk;
       CHECK_AND_ASSERT_MES(generator.construct_block_manually(blk, blk_last, miner_account,
           test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_hf_version | test_generator::bf_max_outs,
-          4, 4, blk_last.timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
+          last_version, last_version, blk_last.timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
-          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 6, 4),
+          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 6, last_version),
           false, "Failed to generate block");
       events.push_back(blk);
       blk_last = blk;
@@ -213,6 +213,8 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
   td.addr = miner_account.get_keys().m_account_address;
   td.amount = amount_paid;
   std::vector<tx_destination_entry> destinations;
+  // from v12, we need two outputs at least
+  destinations.push_back(td);
   destinations.push_back(td);
 
   if (pre_tx)
@@ -223,7 +225,7 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
   std::vector<crypto::secret_key> additional_tx_keys;
   std::unordered_map<crypto::public_key, cryptonote::subaddress_index> subaddresses;
   subaddresses[miner_accounts[0].get_keys().m_account_address.m_spend_public_key] = {0,0};
-  bool r = construct_tx_and_get_tx_key(miner_accounts[0].get_keys(), subaddresses, sources, destinations, cryptonote::account_public_address{}, std::vector<uint8_t>(), tx, 0, tx_key, additional_tx_keys, true);
+  bool r = construct_tx_and_get_tx_key(miner_accounts[0].get_keys(), subaddresses, sources, destinations, cryptonote::account_public_address{}, std::vector<uint8_t>(), tx, 0, tx_key, additional_tx_keys, true, rct_config);
   CHECK_AND_ASSERT_MES(r, false, "failed to construct transaction");
 
   if (post_tx)
@@ -237,6 +239,15 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
   return true;
 }
 
+bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& events,
+    const int *out_idx, int mixin, uint64_t amount_paid, bool valid,
+    const std::function<void(std::vector<tx_source_entry> &sources, std::vector<tx_destination_entry> &destinations)> &pre_tx,
+    const std::function<void(transaction &tx)> &post_tx) const
+{
+  const rct::RCTConfig rct_config { rct::RangeProofBorromean, 0 };
+  return generate_with_full(events, out_idx, mixin, amount_paid, CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE, 4, rct_config, valid, pre_tx, post_tx);
+}
+
 bool gen_rct_tx_valid_from_pre_rct::generate(std::vector<test_event_entry>& events) const
 {
   const int mixin = 2;
@@ -507,3 +518,11 @@ bool gen_rct_tx_rct_altered_extra::generate(std::vector<test_event_entry>& event
     NULL, [&failed](transaction &tx) {std::string extra_nonce; crypto::hash pid = crypto::null_hash; set_payment_id_to_tx_extra_nonce(extra_nonce, pid); if (!add_extra_nonce_to_tx_extra(tx.extra, extra_nonce)) failed = true; }) && !failed;
 }
 
+bool gen_rct_tx_uses_output_too_early::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 10;
+  const int out_idx[] = {1, -1};
+  const uint64_t amount_paid = 10000;
+  const rct::RCTConfig rct_config { rct::RangeProofPaddedBulletproof, 2 };
+  return generate_with_full(events, out_idx, mixin, amount_paid, CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE-3, HF_VERSION_ENFORCE_MIN_AGE, rct_config, false, NULL, NULL);
+}

tests/core_tests/rct.h

@@ -69,6 +69,10 @@ struct gen_rct_tx_validation_base : public test_chain_unit_base
     return true;
   }
 
+  bool generate_with_full(std::vector<test_event_entry>& events, const int *out_idx, int mixin,
+      uint64_t amount_paid, size_t second_rewind, uint8_t last_version, const rct::RCTConfig &rct_config, bool valid,
+      const std::function<void(std::vector<cryptonote::tx_source_entry> &sources, std::vector<cryptonote::tx_destination_entry> &destinations)> &pre_tx,
+      const std::function<void(cryptonote::transaction &tx)> &post_tx) const;
   bool generate_with(std::vector<test_event_entry>& events, const int *out_idx, int mixin,
       uint64_t amount_paid, bool valid,
       const std::function<void(std::vector<cryptonote::tx_source_entry> &sources, std::vector<cryptonote::tx_destination_entry> &destinations)> &pre_tx,
@@ -262,3 +266,13 @@ struct gen_rct_tx_rct_altered_extra : public gen_rct_tx_validation_base
 };
 template<> struct get_test_options<gen_rct_tx_rct_altered_extra>: public get_test_options<gen_rct_tx_validation_base> {};
 
+struct gen_rct_tx_uses_output_too_early : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_uses_output_too_early> {
+  const std::pair<uint8_t, uint64_t> hard_forks[5] = {std::make_pair(1, 0), std::make_pair(2, 1), std::make_pair(4, 65), std::make_pair(12, 69), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};