Add view tags to outputs to reduce wallet scanning time

Implements view tags as proposed by @UkoeHB in MRL issue
https://github.com/monero-project/research-lab/issues/73

At tx construction, the sender adds a 1-byte view tag to each
output. The view tag is derived from the sender-receiver
shared secret. When scanning for outputs, the receiver can
check the view tag for a match, in order to reduce scanning
time. When the view tag does not match, the wallet avoids the
more expensive EC operations when deriving the output public
key using the shared secret.

7 files changed, 363 insertions, 17 deletions

diff --git a/tests/core_tests/block_validation.cpp b/tests/core_tests/block_validation.cpp
index 28f1de7d0..711f67b41 100644
--- a/tests/core_tests/block_validation.cpp
+++ b/tests/core_tests/block_validation.cpp
@@ -671,3 +671,127 @@ bool gen_block_low_coinbase::generate(std::vector<test_event_entry>& events) con
 
   return true;
 }
+
+bool gen_block_miner_tx_out_has_no_view_tag_before_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  bool use_view_tags = false;
+
+  BLOCK_VALIDATION_INIT_GENERATE();
+
+  MAKE_MINER_TX_MANUALLY(miner_tx, blk_0);
+
+  CHECK_AND_ASSERT_MES(!cryptonote::get_output_view_tag(miner_tx.vout[0]), false, "output should not have a view tag");
+
+  crypto::public_key output_public_key;
+  crypto::view_tag view_tag;
+  cryptonote::get_output_public_key(miner_tx.vout[0], output_public_key);
+
+  // explicitly call the setter to ensure it does not set a view tag on the miner tx output
+  cryptonote::set_tx_out(miner_tx.vout[0].amount, output_public_key, use_view_tags, view_tag, miner_tx.vout[0]);
+  CHECK_AND_ASSERT_MES(!cryptonote::get_output_view_tag(miner_tx.vout[0]), false, "output should still not have a view tag");
+
+  block blk_1;
+  generator.construct_block_manually(blk_1, blk_0, miner_account, test_generator::bf_miner_tx, 0, 0, 0, crypto::hash(), 0, miner_tx);
+  events.push_back(blk_1);
+
+  DO_CALLBACK(events, "check_block_accepted");
+
+  return true;
+}
+
+bool gen_block_miner_tx_out_has_no_view_tag_from_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  bool use_view_tags = false;
+
+  BLOCK_VALIDATION_INIT_GENERATE();
+
+  keypair txkey;
+  MAKE_MINER_TX_AND_KEY_AT_HF_MANUALLY(miner_tx, blk_0, HF_VERSION_VIEW_TAGS+1, &txkey);
+
+  crypto::public_key output_public_key;
+  crypto::view_tag view_tag;
+  cryptonote::get_output_public_key(miner_tx.vout[0], output_public_key);
+
+  // remove the view tag that is currently set on the miner tx output at this point
+  cryptonote::set_tx_out(miner_tx.vout[0].amount, output_public_key, use_view_tags, view_tag, miner_tx.vout[0]);
+  CHECK_AND_ASSERT_MES(!cryptonote::get_output_view_tag(miner_tx.vout[0]), false, "output should not have a view tag");
+
+  block blk_1;
+  generator.construct_block_manually(blk_1, blk_0, miner_account,
+      test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_miner_tx,
+      HF_VERSION_VIEW_TAGS+1, HF_VERSION_VIEW_TAGS+1, 0, crypto::hash(), 0, miner_tx);
+  events.push_back(blk_1);
+
+  DO_CALLBACK(events, "check_block_purged");
+
+  return true;
+}
+
+bool gen_block_miner_tx_out_has_view_tag_before_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  bool use_view_tags = true;
+
+  BLOCK_VALIDATION_INIT_GENERATE();
+
+  keypair txkey;
+  MAKE_MINER_TX_AND_KEY_MANUALLY(miner_tx, blk_0, &txkey);
+
+  // derive the view tag for the miner tx output
+  crypto::key_derivation derivation;
+  crypto::public_key output_public_key;
+  crypto::view_tag view_tag;
+  crypto::generate_key_derivation(miner_account.get_keys().m_account_address.m_view_public_key, txkey.sec, derivation);
+  crypto::derive_public_key(derivation, 0, miner_account.get_keys().m_account_address.m_spend_public_key, output_public_key);
+  crypto::derive_view_tag(derivation, 0, view_tag);
+
+  // set the view tag on the miner tx output
+  cryptonote::set_tx_out(miner_tx.vout[0].amount, output_public_key, use_view_tags, view_tag, miner_tx.vout[0]);
+  boost::optional<crypto::view_tag> actual_vt = cryptonote::get_output_view_tag(miner_tx.vout[0]);
+  CHECK_AND_ASSERT_MES(actual_vt && *actual_vt == view_tag, false, "unexpected output view tag");
+
+  block blk_1;
+  generator.construct_block_manually(blk_1, blk_0, miner_account, test_generator::bf_miner_tx, 0, 0, 0, crypto::hash(), 0, miner_tx);
+  events.push_back(blk_1);
+
+  DO_CALLBACK(events, "check_block_purged");
+
+  return true;
+}
+
+bool gen_block_miner_tx_out_has_view_tag_from_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  bool use_view_tags = true;
+
+  BLOCK_VALIDATION_INIT_GENERATE();
+
+  keypair txkey;
+  MAKE_MINER_TX_AND_KEY_AT_HF_MANUALLY(miner_tx, blk_0, HF_VERSION_VIEW_TAGS, &txkey);
+
+  CHECK_AND_ASSERT_MES(cryptonote::get_output_view_tag(miner_tx.vout[0]), false, "output should have a view tag");
+
+  // derive the view tag for the miner tx output
+  crypto::key_derivation derivation;
+  crypto::public_key output_public_key;
+  crypto::view_tag view_tag;
+  crypto::generate_key_derivation(miner_account.get_keys().m_account_address.m_view_public_key, txkey.sec, derivation);
+  crypto::derive_public_key(derivation, 0, miner_account.get_keys().m_account_address.m_spend_public_key, output_public_key);
+  crypto::derive_view_tag(derivation, 0, view_tag);
+
+  boost::optional<crypto::view_tag> actual_vt = cryptonote::get_output_view_tag(miner_tx.vout[0]);
+  CHECK_AND_ASSERT_MES(actual_vt && *actual_vt == view_tag, false, "unexpected output view tag");
+
+  // set the view tag on the miner tx output
+  cryptonote::set_tx_out(miner_tx.vout[0].amount, output_public_key, use_view_tags, view_tag, miner_tx.vout[0]);
+  boost::optional<crypto::view_tag> actual_vt_after_setting = cryptonote::get_output_view_tag(miner_tx.vout[0]);
+  CHECK_AND_ASSERT_MES(actual_vt_after_setting && *actual_vt_after_setting == view_tag, false, "unexpected output view tag after setting");
+
+  block blk_1;
+  generator.construct_block_manually(blk_1, blk_0, miner_account,
+      test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_miner_tx,
+      HF_VERSION_VIEW_TAGS, HF_VERSION_VIEW_TAGS, 0, crypto::hash(), 0, miner_tx);
+  events.push_back(blk_1);
+
+  DO_CALLBACK(events, "check_block_accepted");
+
+  return true;
+}
diff --git a/tests/core_tests/block_validation.h b/tests/core_tests/block_validation.h
index 2535039fb..3a157aaa9 100644
--- a/tests/core_tests/block_validation.h
+++ b/tests/core_tests/block_validation.h
@@ -230,3 +230,37 @@ struct get_test_options<gen_block_low_coinbase> {
     hard_forks, 0
   };
 };
+
+struct gen_block_miner_tx_out_has_no_view_tag_before_hf_view_tags : public gen_block_accepted_base<2>
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+
+struct gen_block_miner_tx_out_has_no_view_tag_from_hf_view_tags : public gen_block_verification_base<1>
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<>
+struct get_test_options<gen_block_miner_tx_out_has_no_view_tag_from_hf_view_tags> {
+  const std::pair<uint8_t, uint64_t> hard_forks[3] = {std::make_pair(1, 0), std::make_pair(HF_VERSION_VIEW_TAGS+1, 1), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
+
+struct gen_block_miner_tx_out_has_view_tag_before_hf_view_tags : public gen_block_verification_base<1>
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+
+struct gen_block_miner_tx_out_has_view_tag_from_hf_view_tags : public gen_block_accepted_base<2>
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<>
+struct get_test_options<gen_block_miner_tx_out_has_view_tag_from_hf_view_tags> {
+  const std::pair<uint8_t, uint64_t> hard_forks[3] = {std::make_pair(1, 0), std::make_pair(HF_VERSION_VIEW_TAGS, 1), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
diff --git a/tests/core_tests/chaingen.cpp b/tests/core_tests/chaingen.cpp
index 689b6801b..61195c7b0 100644
--- a/tests/core_tests/chaingen.cpp
+++ b/tests/core_tests/chaingen.cpp
@@ -462,7 +462,9 @@ bool init_output_indices(map_output_idx_t& outs, std::map<uint64_t, std::vector<
                     size_t tx_global_idx = outs[out.amount].size() - 1;
                     outs[out.amount][tx_global_idx].idx = tx_global_idx;
                     // Is out to me?
-                    if (is_out_to_acc(from.get_keys(), boost::get<txout_to_key>(out.target), get_tx_pub_key_from_extra(tx), get_additional_tx_pub_keys_from_extra(tx), j)) {
+                    crypto::public_key output_public_key;
+                    cryptonote::get_output_public_key(out, output_public_key);
+                    if (is_out_to_acc(from.get_keys(), output_public_key, get_tx_pub_key_from_extra(tx), get_additional_tx_pub_keys_from_extra(tx), j)) {
                         outs_mine[out.amount].push_back(tx_global_idx);
                     }
                 }
@@ -972,7 +974,7 @@ std::vector<cryptonote::tx_destination_entry> build_dsts(std::initializer_list<d
 
 bool construct_miner_tx_manually(size_t height, uint64_t already_generated_coins,
                                  const account_public_address& miner_address, transaction& tx, uint64_t fee,
-                                 keypair* p_txkey/* = 0*/)
+                                 uint8_t hf_version/* = 1*/, keypair* p_txkey/* = 0*/)
 {
   keypair txkey;
   txkey = keypair::generate(hw::get_device("default"));
@@ -987,7 +989,7 @@ bool construct_miner_tx_manually(size_t height, uint64_t already_generated_coins
 
   // This will work, until size of constructed block is less then CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE
   uint64_t block_reward;
-  if (!get_block_reward(0, 0, already_generated_coins, block_reward, 1))
+  if (!get_block_reward(0, 0, already_generated_coins, block_reward, hf_version))
   {
     LOG_PRINT_L0("Block is too big");
     return false;
@@ -999,12 +1001,20 @@ bool construct_miner_tx_manually(size_t height, uint64_t already_generated_coins
   crypto::generate_key_derivation(miner_address.m_view_public_key, txkey.sec, derivation);
   crypto::derive_public_key(derivation, 0, miner_address.m_spend_public_key, out_eph_public_key);
 
+  bool use_view_tags = hf_version >= HF_VERSION_VIEW_TAGS;
+  crypto::view_tag view_tag;
+  if (use_view_tags)
+    crypto::derive_view_tag(derivation, 0, view_tag);
+
   tx_out out;
-  out.amount = block_reward;
-  out.target = txout_to_key(out_eph_public_key);
+  cryptonote::set_tx_out(block_reward, out_eph_public_key, use_view_tags, view_tag, out);
+
   tx.vout.push_back(out);
 
-  tx.version = 1;
+  if (hf_version >= HF_VERSION_DYNAMIC_FEE)
+    tx.version = 2;
+  else
+    tx.version = 1;
   tx.unlock_time = height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW;
 
   return true;
diff --git a/tests/core_tests/chaingen.h b/tests/core_tests/chaingen.h
index c1e592b86..5c8c9f79f 100644
--- a/tests/core_tests/chaingen.h
+++ b/tests/core_tests/chaingen.h
@@ -423,7 +423,8 @@ uint64_t sum_amount(const std::vector<cryptonote::tx_source_entry>& sources);
 
 bool construct_miner_tx_manually(size_t height, uint64_t already_generated_coins,
                                  const cryptonote::account_public_address& miner_address, cryptonote::transaction& tx,
-                                 uint64_t fee, cryptonote::keypair* p_txkey = nullptr);
+                                 uint64_t fee, uint8_t hf_version = 1,
+                                 cryptonote::keypair* p_txkey = nullptr);
 
 bool construct_tx_to_key(const std::vector<test_event_entry>& events, cryptonote::transaction& tx,
                          const cryptonote::block& blk_head, const cryptonote::account_base& from, const var_addr_t& to, uint64_t amount,
@@ -967,12 +968,14 @@ inline bool do_replay_file(const std::string& filename)
     std::list<cryptonote::transaction> SET_NAME; \
     MAKE_TX_MIX_LIST_RCT(VEC_EVENTS, SET_NAME, FROM, TO, AMOUNT, NMIX, HEAD);
 
-#define MAKE_MINER_TX_AND_KEY_MANUALLY(TX, BLK, KEY)                                                      \
+#define MAKE_MINER_TX_AND_KEY_AT_HF_MANUALLY(TX, BLK, HF_VERSION, KEY)                                    \
   transaction TX;                                                                                         \
   if (!construct_miner_tx_manually(get_block_height(BLK) + 1, generator.get_already_generated_coins(BLK), \
-    miner_account.get_keys().m_account_address, TX, 0, KEY))                                              \
+    miner_account.get_keys().m_account_address, TX, 0, HF_VERSION, KEY))                                  \
     return false;
 
+#define MAKE_MINER_TX_AND_KEY_MANUALLY(TX, BLK, KEY) MAKE_MINER_TX_AND_KEY_AT_HF_MANUALLY(TX, BLK, 1, KEY)
+
 #define MAKE_MINER_TX_MANUALLY(TX, BLK) MAKE_MINER_TX_AND_KEY_MANUALLY(TX, BLK, 0)
 
 #define SET_EVENT_VISITOR_SETT(VEC_EVENTS, SETT) VEC_EVENTS.push_back(event_visitor_settings(SETT));
diff --git a/tests/core_tests/chaingen_main.cpp b/tests/core_tests/chaingen_main.cpp
index 2e2d170ff..b89dff445 100644
--- a/tests/core_tests/chaingen_main.cpp
+++ b/tests/core_tests/chaingen_main.cpp
@@ -133,6 +133,10 @@ int main(int argc, char* argv[])
     GENERATE_AND_PLAY(gen_block_miner_tx_out_is_big);
     GENERATE_AND_PLAY(gen_block_miner_tx_has_no_out);
     GENERATE_AND_PLAY(gen_block_miner_tx_has_out_to_alice);
+    GENERATE_AND_PLAY(gen_block_miner_tx_out_has_no_view_tag_before_hf_view_tags);
+    GENERATE_AND_PLAY(gen_block_miner_tx_out_has_no_view_tag_from_hf_view_tags);
+    GENERATE_AND_PLAY(gen_block_miner_tx_out_has_view_tag_before_hf_view_tags);
+    GENERATE_AND_PLAY(gen_block_miner_tx_out_has_view_tag_from_hf_view_tags);
     GENERATE_AND_PLAY(gen_block_has_invalid_tx);
     GENERATE_AND_PLAY(gen_block_is_too_big);
     GENERATE_AND_PLAY(gen_block_invalid_binary_format); // Takes up to 3 hours, if CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW == 500, up to 30 minutes, if CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW == 10
@@ -219,6 +223,15 @@ 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_pre_rct_has_no_view_tag_before_hf_view_tags);
+    // TODO: base test needs to be restructured to handle pre rct outputs after HF v12
+    // GENERATE_AND_PLAY(gen_rct_tx_pre_rct_has_no_view_tag_from_hf_view_tags);
+    GENERATE_AND_PLAY(gen_rct_tx_pre_rct_has_view_tag_before_hf_view_tags);
+    // GENERATE_AND_PLAY(gen_rct_tx_pre_rct_has_view_tag_from_hf_view_tags);
+    GENERATE_AND_PLAY(gen_rct_tx_rct_has_no_view_tag_before_hf_view_tags);
+    GENERATE_AND_PLAY(gen_rct_tx_rct_has_no_view_tag_from_hf_view_tags);
+    GENERATE_AND_PLAY(gen_rct_tx_rct_has_view_tag_before_hf_view_tags);
+    GENERATE_AND_PLAY(gen_rct_tx_rct_has_view_tag_from_hf_view_tags);
     GENERATE_AND_PLAY(gen_rct_tx_uses_output_too_early);
 
     GENERATE_AND_PLAY(gen_multisig_tx_valid_22_1_2);
diff --git a/tests/core_tests/rct.cpp b/tests/core_tests/rct.cpp
index 3a26de4c2..0926483fe 100644
--- a/tests/core_tests/rct.cpp
+++ b/tests/core_tests/rct.cpp
@@ -41,7 +41,7 @@ using namespace cryptonote;
 // Tests
 
 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, size_t second_rewind, uint8_t last_version, const rct::RCTConfig &rct_config, 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 use_view_tags, 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
 {
@@ -98,7 +98,9 @@ bool gen_rct_tx_validation_base::generate_with_full(std::vector<test_event_entry
     const size_t index_in_tx = 5;
     src.amount = 30000000000000;
     for (int m = 0; m < 4; ++m) {
-      src.push_output(m, boost::get<txout_to_key>(blocks[m].miner_tx.vout[index_in_tx].target).key, src.amount);
+      crypto::public_key output_public_key;
+      cryptonote::get_output_public_key(blocks[m].miner_tx.vout[index_in_tx], output_public_key);
+      src.push_output(m, output_public_key, src.amount);
     }
     src.real_out_tx_key = cryptonote::get_tx_pub_key_from_extra(blocks[n].miner_tx);
     src.real_output = n;
@@ -139,10 +141,13 @@ bool gen_rct_tx_validation_base::generate_with_full(std::vector<test_event_entry
         rct::decodeRct(rct_txes[n].rct_signatures, rct::sk2rct(amount_key), o, rct_tx_masks[o+n*4], hw::get_device("default"));
     }
 
+    uint64_t fee = 0;
+    get_tx_fee(rct_txes[n], fee);
+
     CHECK_AND_ASSERT_MES(generator.construct_block_manually(blk_txes[n], blk_last, miner_account,
-        test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_tx_hashes | test_generator::bf_hf_version | test_generator::bf_max_outs,
+        test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_tx_hashes | test_generator::bf_hf_version | test_generator::bf_max_outs | test_generator::bf_tx_fees,
         4, 4, blk_last.timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
-        crypto::hash(), 0, transaction(), starting_rct_tx_hashes, 0, 6, 4),
+        crypto::hash(), 0, transaction(), starting_rct_tx_hashes, 0, 6, 4, fee),
         false, "Failed to generate block");
     events.push_back(blk_txes[n]);
     blk_last = blk_txes[n];
@@ -224,7 +229,7 @@ bool gen_rct_tx_validation_base::generate_with_full(std::vector<test_event_entry
   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, rct_config);
+  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, NULL, use_view_tags);
   CHECK_AND_ASSERT_MES(r, false, "failed to construct transaction");
 
   if (post_tx)
@@ -244,7 +249,8 @@ bool gen_rct_tx_validation_base::generate_with(std::vector<test_event_entry>& ev
     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 use_view_tags = false;
+  return generate_with_full(events, out_idx, mixin, amount_paid, CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE, 4, rct_config, use_view_tags, valid, pre_tx, post_tx);
 }
 
 bool gen_rct_tx_valid_from_pre_rct::generate(std::vector<test_event_entry>& events) const
@@ -517,11 +523,99 @@ 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_pre_rct_has_no_view_tag_before_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 2;
+  const int out_idx[] = {0, -1};
+  const uint64_t amount_paid = 10000;
+  bool use_view_tags = false;
+  bool valid = true;
+  return generate_with_full(events, out_idx, mixin, amount_paid, 0, 0, {}, use_view_tags, valid, NULL, NULL);
+}
+
+bool gen_rct_tx_pre_rct_has_no_view_tag_from_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 10;
+  const int out_idx[] = {0, -1};
+  const uint64_t amount_paid = 10000;
+  const rct::RCTConfig rct_config { rct::RangeProofPaddedBulletproof, 3 };
+  bool use_view_tags = false;
+  bool valid = false;
+  return generate_with_full(events, out_idx, mixin, amount_paid, CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE, HF_VERSION_VIEW_TAGS, rct_config, use_view_tags, valid, NULL, NULL);
+}
+
+bool gen_rct_tx_pre_rct_has_view_tag_before_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 2;
+  const int out_idx[] = {0, -1};
+  const uint64_t amount_paid = 10000;
+  bool use_view_tags = true;
+  bool valid = false;
+  return generate_with_full(events, out_idx, mixin, amount_paid, 0, 0, {}, use_view_tags, valid, NULL, NULL);
+}
+
+bool gen_rct_tx_pre_rct_has_view_tag_from_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 10;
+  const int out_idx[] = {0, -1};
+  const uint64_t amount_paid = 10000;
+  const rct::RCTConfig rct_config { rct::RangeProofPaddedBulletproof, 3 };
+  bool use_view_tags = true;
+  bool valid = true;
+  return generate_with_full(events, out_idx, mixin, amount_paid, CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE, HF_VERSION_VIEW_TAGS, rct_config, use_view_tags, valid, NULL, NULL);
+}
+
+bool gen_rct_tx_rct_has_no_view_tag_before_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 2;
+  const int out_idx[] = {1, -1};
+  const uint64_t amount_paid = 10000;
+  const rct::RCTConfig rct_config { rct::RangeProofBorromean, 0 };
+  bool use_view_tags = false;
+  bool valid = true;
+  return generate_with_full(events, out_idx, mixin, amount_paid, 0, 0, rct_config, use_view_tags, valid, NULL, NULL);
+}
+
+bool gen_rct_tx_rct_has_no_view_tag_from_hf_view_tags::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, 3 };
+  bool use_view_tags = false;
+  bool valid = false;
+  return generate_with_full(events, out_idx, mixin, amount_paid, CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE, HF_VERSION_VIEW_TAGS+1, rct_config, use_view_tags, valid, NULL, NULL);
+}
+
+bool gen_rct_tx_rct_has_view_tag_before_hf_view_tags::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 2;
+  const int out_idx[] = {1, -1};
+  const uint64_t amount_paid = 10000;
+  const rct::RCTConfig rct_config { rct::RangeProofBorromean, 0 };
+  bool use_view_tags = true;
+  bool valid = false;
+  return generate_with_full(events, out_idx, mixin, amount_paid, 0, 0, rct_config, use_view_tags, valid, NULL, NULL);
+}
+
+bool gen_rct_tx_rct_has_view_tag_from_hf_view_tags::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, 3 };
+  bool use_view_tags = true;
+  bool valid = true;
+  return generate_with_full(events, out_idx, mixin, amount_paid, CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE, HF_VERSION_VIEW_TAGS, rct_config, use_view_tags, valid, NULL, NULL);
+}
+
 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);
+  bool use_view_tags = false;
+  bool valid = false;
+  return generate_with_full(events, out_idx, mixin, amount_paid, CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE-3, HF_VERSION_ENFORCE_MIN_AGE, rct_config, use_view_tags, valid, NULL, NULL);
 }
diff --git a/tests/core_tests/rct.h b/tests/core_tests/rct.h
index dee074e4c..c20e8a580 100644
--- a/tests/core_tests/rct.h
+++ b/tests/core_tests/rct.h
@@ -70,7 +70,7 @@ struct gen_rct_tx_validation_base : public test_chain_unit_base
   }
 
   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,
+      uint64_t amount_paid, size_t second_rewind, uint8_t last_version, const rct::RCTConfig &rct_config, bool use_view_tags, 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,
@@ -266,6 +266,74 @@ 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_pre_rct_has_no_view_tag_before_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_pre_rct_has_no_view_tag_before_hf_view_tags>: public get_test_options<gen_rct_tx_validation_base> {};
+
+struct gen_rct_tx_pre_rct_has_no_view_tag_from_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_pre_rct_has_no_view_tag_from_hf_view_tags> {
+  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(HF_VERSION_VIEW_TAGS, 69), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
+
+struct gen_rct_tx_pre_rct_has_view_tag_before_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_pre_rct_has_view_tag_before_hf_view_tags>: public get_test_options<gen_rct_tx_validation_base> {};
+
+struct gen_rct_tx_pre_rct_has_view_tag_from_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_pre_rct_has_view_tag_from_hf_view_tags> {
+  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(HF_VERSION_VIEW_TAGS, 69), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
+
+struct gen_rct_tx_rct_has_no_view_tag_before_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_rct_has_no_view_tag_before_hf_view_tags>: public get_test_options<gen_rct_tx_validation_base> {};
+
+struct gen_rct_tx_rct_has_no_view_tag_from_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_rct_has_no_view_tag_from_hf_view_tags> {
+  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(HF_VERSION_VIEW_TAGS+1, 69), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
+
+struct gen_rct_tx_rct_has_view_tag_before_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_rct_has_view_tag_before_hf_view_tags>: public get_test_options<gen_rct_tx_validation_base> {};
+
+struct gen_rct_tx_rct_has_view_tag_from_hf_view_tags : public gen_rct_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_rct_tx_rct_has_view_tag_from_hf_view_tags> {
+  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(HF_VERSION_VIEW_TAGS, 69), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks, 0
+  };
+};
+
 struct gen_rct_tx_uses_output_too_early : public gen_rct_tx_validation_base
 {
   bool generate(std::vector<test_event_entry>& events) const;