bumped RC version

src/blockchain_db/lmdb/db_lmdb.cpp

@@ -1261,7 +1261,17 @@ uint64_t BlockchainLMDB::add_transaction_data(const crypto::hash& blk_hash, cons
     yield_tx_info yield_data;
     yield_data.block_height = m_height;
     yield_data.tx_hash = tx_hash;
-    yield_data.return_address = tx.return_address;
+    if (tx.version == TRANSACTION_VERSION_2_OUTS) {
+      if (tx.return_address == crypto::null_pkey)
+        throw0(DB_ERROR("missing return_address entry (needed to create yield data for PROTOCOL_TX)  - v2 STAKE"));
+      yield_data.return_address = tx.return_address;
+    } else if (tx.version >= TRANSACTION_VERSION_N_OUTS) {
+      if (tx.return_address_list.empty())
+        throw0(DB_ERROR("no return_address_list entry (needed to create yield data for the PROTOCOL_TX)"));
+      else if (tx.return_address_list.size() > 1)
+        throw0(DB_ERROR("too many return_address_list entries provided (only one needed to create yield data for the PROTOCOL_TX)"));
+      yield_data.return_address = tx.return_address_list[0];
+    }
     yield_data.locked_coins = tx.amount_burnt;
     if (tx.vin.empty())
       throw0(DB_ERROR("tx.vin is empty (needed to create yield data for the PROTOCOL_TX)"));

src/blockchain_utilities/CMakeLists.txt

@@ -133,6 +133,16 @@ monero_private_headers(blockchain_stats
 	  ${blockchain_stats_private_headers})
 
 
+set(blockchain_scanner_sources
+  blockchain_scanner.cpp
+  )
+
+set(blockchain_scanner_private_headers)
+
+monero_private_headers(blockchain_scanner
+	  ${blockchain_scanner_private_headers})
+
+
 monero_add_executable(blockchain_import
   ${blockchain_import_sources}
   ${blockchain_import_private_headers})
@@ -281,6 +291,27 @@ set_property(TARGET blockchain_depth
 	OUTPUT_NAME "salvium-blockchain-depth")
 install(TARGETS blockchain_depth DESTINATION bin)
 
+monero_add_executable(blockchain_scanner
+  ${blockchain_scanner_sources}
+  ${blockchain_scanner_private_headers})
+
+target_link_libraries(blockchain_scanner
+  PRIVATE
+    cryptonote_core
+    blockchain_db
+    version
+    epee
+    ${Boost_FILESYSTEM_LIBRARY}
+    ${Boost_SYSTEM_LIBRARY}
+    ${Boost_THREAD_LIBRARY}
+    ${CMAKE_THREAD_LIBS_INIT}
+    ${EXTRA_LIBRARIES})
+
+set_property(TARGET blockchain_scanner
+	PROPERTY
+	OUTPUT_NAME "salvium-blockchain-scanner")
+install(TARGETS blockchain_scanner DESTINATION bin)
+
 monero_add_executable(blockchain_stats
   ${blockchain_stats_sources}
   ${blockchain_stats_private_headers})

src/cryptonote_basic/cryptonote_basic.h

@@ -200,8 +200,11 @@ namespace cryptonote
     std::vector<uint8_t> extra;
     // TX type
     cryptonote::transaction_type type;
-    // Return address
     crypto::public_key return_address;
+    // Return address list (must be at least 1 and at most BULLETPROOF_MAX_OUTPUTS-1 - the "-1" is for the change output)
+    std::vector<crypto::public_key> return_address_list;
+    //return_address_change_mask
+    std::vector<uint8_t> return_address_change_mask;
     // Return TX public key
     crypto::public_key return_pubkey;
     // Source asset type
@@ -224,8 +227,13 @@ namespace cryptonote
       if (type != cryptonote::transaction_type::PROTOCOL) {
         VARINT_FIELD(amount_burnt)
         if (type != cryptonote::transaction_type::MINER) {
-          FIELD(return_address)
-          FIELD(return_pubkey)
+          if (type == cryptonote::transaction_type::TRANSFER && version >= TRANSACTION_VERSION_N_OUTS) {
+            FIELD(return_address_list)
+            FIELD(return_address_change_mask)
+          } else {
+            FIELD(return_address)
+            FIELD(return_pubkey)
+          }
           FIELD(source_asset_type)
           FIELD(destination_asset_type)
           VARINT_FIELD(amount_slippage_limit)
@@ -244,6 +252,8 @@ namespace cryptonote
       extra.clear();
       type = cryptonote::transaction_type::UNSET;
       return_address = crypto::null_pkey;
+      return_address_list.clear();
+      return_address_change_mask.clear();
       return_pubkey = crypto::null_pkey;
       source_asset_type.clear();
       destination_asset_type.clear();

src/cryptonote_basic/cryptonote_boost_serialization.h

@@ -166,24 +166,7 @@ namespace boost
   inline void serialize(Archive &a, cryptonote::transaction_prefix &x, const boost::serialization::version_type ver)
   {
     a & x.version;
-    a & x.vin;
-    a & x.vout;
-    a & x.extra;
-    a & x.type;
-    if (x.type != cryptonote::transaction_type::MINER && x.type != cryptonote::transaction_type::PROTOCOL) {
-      a & x.return_address;
-      a & x.return_pubkey;
-      a & x.source_asset_type;
-      a & x.destination_asset_type;
-      a & x.amount_burnt;
-      a & x.amount_slippage_limit;
-    }
-  }
-
-  template <class Archive>
-  inline void serialize(Archive &a, cryptonote::transaction &x, const boost::serialization::version_type ver)
-  {
-    a & x.version;
+    a & x.unlock_time;
     a & x.vin;
     a & x.vout;
     a & x.extra;
@@ -191,8 +174,39 @@ namespace boost
     if (x.type != cryptonote::transaction_type::PROTOCOL) {
       a & x.amount_burnt;
       if (x.type != cryptonote::transaction_type::MINER) {
-        a & x.return_address;
-        a & x.return_pubkey;
+        if (x.type == cryptonote::transaction_type::TRANSFER && x.version >= TRANSACTION_VERSION_N_OUTS) {
+          a & x.return_address_list;
+          a & x.return_address_change_mask;
+        } else {
+          a & x.return_address;
+          a & x.return_pubkey;
+        }
+        a & x.source_asset_type;
+        a & x.destination_asset_type;
+        a & x.amount_slippage_limit;
+      }
+    }
+  }
+
+  template <class Archive>
+  inline void serialize(Archive &a, cryptonote::transaction &x, const boost::serialization::version_type ver)
+  {
+    a & x.version;
+    a & x.unlock_time;
+    a & x.vin;
+    a & x.vout;
+    a & x.extra;
+    a & x.type;
+    if (x.type != cryptonote::transaction_type::PROTOCOL) {
+      a & x.amount_burnt;
+      if (x.type != cryptonote::transaction_type::MINER) {
+        if (x.type == cryptonote::transaction_type::TRANSFER && x.version >= TRANSACTION_VERSION_N_OUTS) {
+          a & x.return_address_list;
+          a & x.return_address_change_mask;
+        } else {
+          a & x.return_address;
+          a & x.return_pubkey;
+        }
         a & x.source_asset_type;
         a & x.destination_asset_type;
         a & x.amount_slippage_limit;

src/cryptonote_basic/cryptonote_format_utils.cpp

@@ -1724,7 +1724,7 @@ namespace cryptonote
     blobdata blob = t_serializable_object_to_blob(static_cast<block_header>(b));
     crypto::hash tree_root_hash = get_tx_tree_hash(b);
     blob.append(reinterpret_cast<const char*>(&tree_root_hash), sizeof(tree_root_hash));
-    blob.append(tools::get_varint_data(b.tx_hashes.size()+1));
+    blob.append(tools::get_varint_data(b.tx_hashes.size() + (b.major_version >= HF_VERSION_ENABLE_N_OUTS ? 2 : 1)));
     return blob;
   }
   //---------------------------------------------------------------

src/cryptonote_basic/difficulty.cpp

@@ -33,6 +33,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <vector>
+#include <boost/math/special_functions/round.hpp>
 
 #include "int-util.h"
 #include "crypto/hash.h"
@@ -239,6 +240,63 @@ namespace cryptonote {
     return res.convert_to<difficulty_type>();
   }
 
+  difficulty_type next_difficulty_v2(std::vector<std::uint64_t> timestamps, std::vector<difficulty_type> cumulative_difficulties, size_t target_seconds) {
+
+    // LWMA difficulty algorithm
+    // Copyright (c) 2017-2018 Zawy
+    // MIT license http://www.opensource.org/licenses/mit-license.php.
+    // This is an improved version of Tom Harding's (Deger8) "WT-144"
+    // Karbowanec, Masari, Bitcoin Gold, and Bitcoin Cash have contributed.
+    // See https://github.com/zawy12/difficulty-algorithms/issues/3 for other algos.
+    // Do not use "if solvetime < 0 then solvetime = 1" which allows a catastrophic exploit.
+    // T= target_solvetime;
+    // N=45, 55, 70, 90, 120 for T=600, 240, 120, 90, and 60
+
+    const int64_t T = static_cast<int64_t>(target_seconds);
+    size_t N = DIFFICULTY_WINDOW;
+
+    if (timestamps.size() > N) {
+      timestamps.resize(N + 1);
+      cumulative_difficulties.resize(N + 1);
+    }
+    size_t n = timestamps.size();
+    assert(n == cumulative_difficulties.size());
+    assert(n <= DIFFICULTY_WINDOW);
+    // If new coin, just "give away" first 5 blocks at low difficulty
+    if ( n < 6 ) { return  1; }
+    // If height "n" is from 6 to N, then reset N to n-1.
+    else if (n < N+1) { N=n-1; }
+
+    // To get an average solvetime to within +/- ~0.1%, use an adjustment factor.
+    // adjust=0.99 for 90 < N < 130
+    const long double adjust = 0.998;
+    // The divisor k normalizes LWMA.
+    const long double k = N * (N + 1) / 2;
+
+    long double LWMA(0), sum_inverse_D(0), harmonic_mean_D(0), nextDifficulty(0);
+    int64_t solveTime(0);
+    uint64_t difficulty(0), next_difficulty(0);
+
+    // Loop through N most recent blocks.
+    for (size_t i = 1; i <= N; i++) {
+      solveTime = static_cast<int64_t>(timestamps[i]) - static_cast<int64_t>(timestamps[i - 1]);
+      solveTime = std::min<int64_t>((T * 7), std::max<int64_t>(solveTime, (-7 * T)));
+      difficulty = (cumulative_difficulties[i] - cumulative_difficulties[i - 1]).convert_to<uint64_t>();
+      LWMA += (int64_t)(solveTime * i) / k;
+      sum_inverse_D += 1 / static_cast<double>(difficulty);
+    }
+
+    // Keep LWMA sane in case something unforeseen occurs.
+    if (static_cast<int64_t>(boost::math::round(LWMA)) < T / 20)
+      LWMA = static_cast<double>(T / 20);
+
+    harmonic_mean_D = N / sum_inverse_D * adjust;
+    nextDifficulty = harmonic_mean_D * T / LWMA;
+    next_difficulty = static_cast<uint64_t>(nextDifficulty);
+
+    return next_difficulty;
+  }
+  
   std::string hex(difficulty_type v)
   {
     static const char chars[] = "0123456789abcdef";

src/cryptonote_basic/difficulty.h

@@ -58,6 +58,7 @@ namespace cryptonote
     bool check_hash_128(const crypto::hash &hash, difficulty_type difficulty);
     bool check_hash(const crypto::hash &hash, difficulty_type difficulty);
     difficulty_type next_difficulty(std::vector<std::uint64_t> timestamps, std::vector<difficulty_type> cumulative_difficulties, size_t target_seconds);
-
+    difficulty_type next_difficulty_v2(std::vector<std::uint64_t> timestamps, std::vector<difficulty_type> cumulative_difficulties, size_t target_seconds);
+  
     std::string hex(difficulty_type v);
 }

src/cryptonote_basic/verification_context.h

@@ -59,6 +59,7 @@ namespace cryptonote
     bool m_fee_too_low;
     bool m_too_few_outputs;
     bool m_tx_extra_too_big;
+    bool m_version_mismatch; // TX version wrong for the currently-active HF version
   };
 
   struct block_verification_context

src/cryptonote_config.h

@@ -42,7 +42,9 @@
 #define CRYPTONOTE_MAX_TX_PER_BLOCK                     0x10000000
 #define CRYPTONOTE_PUBLIC_ADDRESS_TEXTBLOB_VER          0
 #define CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW            60
-#define CURRENT_TRANSACTION_VERSION                     2
+#define CURRENT_TRANSACTION_VERSION                     3
+#define TRANSACTION_VERSION_2_OUTS                      2
+#define TRANSACTION_VERSION_N_OUTS                      3
 #define CURRENT_BLOCK_MAJOR_VERSION                     1
 #define CURRENT_BLOCK_MINOR_VERSION                     1
 #define CRYPTONOTE_BLOCK_FUTURE_TIME_LIMIT              60*60*2
@@ -212,9 +214,11 @@
 
 #define HF_VERSION_LONG_TERM_BLOCK_WEIGHT       2
 #define HF_VERSION_2021_SCALING                 2
-#define HF_VERSION_ENABLE_CONVERT               2
-#define HF_VERSION_ENABLE_ORACLE                2
-#define HF_VERSION_SLIPPAGE_YIELD               2
+#define HF_VERSION_ENABLE_N_OUTS                2
+
+#define HF_VERSION_ENABLE_CONVERT               255
+#define HF_VERSION_ENABLE_ORACLE                255
+#define HF_VERSION_SLIPPAGE_YIELD               255
 
 #define TESTNET_VERSION                         11
 #define STAGENET_VERSION                        1

src/cryptonote_core/blockchain.cpp

@@ -967,7 +967,13 @@ start:
   }
 
   size_t target = get_difficulty_target();
-  difficulty_type diff = next_difficulty(timestamps, difficulties, target);
+  difficulty_type diff;
+  uint8_t version = get_current_hard_fork_version();
+  if (version == 1) {
+    diff = next_difficulty(timestamps, difficulties, target);
+  } else {
+    diff = next_difficulty_v2(timestamps, difficulties, target);
+  }
 
   CRITICAL_REGION_LOCAL1(m_difficulty_lock);
   m_difficulty_for_next_block_top_hash = top_hash;
@@ -1026,6 +1032,7 @@ size_t Blockchain::recalculate_difficulties(boost::optional<uint64_t> start_heig
 
   std::vector<uint64_t> timestamps;
   std::vector<difficulty_type> difficulties;
+  uint8_t version = get_current_hard_fork_version();
   timestamps.reserve(DIFFICULTY_BLOCKS_COUNT + 1);
   difficulties.reserve(DIFFICULTY_BLOCKS_COUNT + 1);
   if (start_height > 1)
@@ -1045,7 +1052,9 @@ size_t Blockchain::recalculate_difficulties(boost::optional<uint64_t> start_heig
   for (uint64_t height = start_height; height <= top_height; ++height)
   {
     size_t target = DIFFICULTY_TARGET_V2;
-    difficulty_type recalculated_diff = next_difficulty(timestamps, difficulties, target);
+    difficulty_type recalculated_diff = (version == 1)
+      ? next_difficulty(timestamps, difficulties, target)
+      : next_difficulty_v2(timestamps, difficulties, target);
 
     boost::multiprecision::uint256_t recalculated_cum_diff_256 = boost::multiprecision::uint256_t(recalculated_diff) + last_cum_diff;
     CHECK_AND_ASSERT_THROW_MES(recalculated_cum_diff_256 <= std::numeric_limits<difficulty_type>::max(), "Difficulty overflow!");
@@ -1299,6 +1308,7 @@ difficulty_type Blockchain::get_next_difficulty_for_alternative_chain(const std:
   LOG_PRINT_L3("Blockchain::" << __func__);
   std::vector<uint64_t> timestamps;
   std::vector<difficulty_type> cumulative_difficulties;
+  uint8_t version = get_current_hard_fork_version();
 
   // if the alt chain isn't long enough to calculate the difficulty target
   // based on its blocks alone, need to get more blocks from the main chain
@@ -1354,7 +1364,11 @@ difficulty_type Blockchain::get_next_difficulty_for_alternative_chain(const std:
   size_t target = DIFFICULTY_TARGET_V2;
 
   // calculate the difficulty target for the block and return it
-  return next_difficulty(timestamps, cumulative_difficulties, target);
+  if (version == 1) {
+    return next_difficulty(timestamps, cumulative_difficulties, target);
+  } else {
+    return next_difficulty_v2(timestamps, cumulative_difficulties, target);
+  }
 }
 //------------------------------------------------------------------
 // This function does a sanity check on basic things that all miner
@@ -1448,6 +1462,7 @@ bool Blockchain::validate_miner_transaction(const block& b, size_t cumulative_bl
 
   switch (version) {
   case HF_VERSION_BULLETPROOF_PLUS:
+  case HF_VERSION_ENABLE_N_OUTS:
     if (b.miner_tx.amount_burnt > 0) {
       CHECK_AND_ASSERT_MES(money_in_use + b.miner_tx.amount_burnt > money_in_use, false, "miner transaction is overflowed by amount_burnt");
       money_in_use += b.miner_tx.amount_burnt;
@@ -3576,6 +3591,43 @@ bool Blockchain::check_tx_outputs(const transaction& tx, tx_verification_context
   return true;
 }
 //------------------------------------------------------------------
+bool Blockchain::check_tx_type_and_version(const transaction& tx, tx_verification_context &tvc) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  const uint8_t hf_version = m_hardfork->get_current_version();
+
+  // Prior to v2, only allow TX v2
+  if (hf_version < HF_VERSION_ENABLE_N_OUTS) {
+
+    // Check for N-out TXs
+    if (tx.version >= TRANSACTION_VERSION_N_OUTS) {
+      MERROR_VER("N-out TXs are not permitted prior to v" + std::to_string(HF_VERSION_ENABLE_N_OUTS));
+      tvc.m_version_mismatch = true;
+      return false;
+    }
+
+    // Check for v1 TXs - genesis block protocol_tx exception required!
+    if (tx.version == 1 && epee::string_tools::pod_to_hex(cryptonote::get_transaction_hash(tx)) == "4f78ff511e860acd03138737a71505eb62eb78b620e180e58c8e13ed0e1e3e19") {
+      MERROR("v1 TXs are not permitted");
+      tvc.m_version_mismatch = true;
+      return false;
+    }
+  }
+
+  // After v2 allow N-out TXs for TRANSFER ONLY
+  if (hf_version >= HF_VERSION_ENABLE_N_OUTS) {
+    if (tx.version >= TRANSACTION_VERSION_N_OUTS && tx.type != cryptonote::transaction_type::TRANSFER) {
+      MERROR("N-out TXs are only permitted for TRANSFER TX type");
+      tvc.m_version_mismatch = true;
+      return false;
+    }
+  }
+  
+  return true;
+}
+//------------------------------------------------------------------
 bool Blockchain::have_tx_keyimges_as_spent(const transaction &tx) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
@@ -3590,7 +3642,7 @@ bool Blockchain::have_tx_keyimges_as_spent(const transaction &tx) const
 bool Blockchain::expand_transaction_2(transaction &tx, const crypto::hash &tx_prefix_hash, const std::vector<std::vector<rct::ctkey>> &pubkeys, const uint8_t &hf_version)
 {
   PERF_TIMER(expand_transaction_2);
-  CHECK_AND_ASSERT_MES(tx.version == 2, false, "Transaction version is not 2");
+  CHECK_AND_ASSERT_MES(tx.version == 2 || tx.version == 3, false, "Transaction version is not 2/3");
 
   rct::rctSig &rv = tx.rct_signatures;
 
@@ -3779,7 +3831,7 @@ bool Blockchain::check_tx_inputs(transaction& tx, tx_verification_context &tvc,
     }
 
     // min/max tx version based on HF, and we accept v1 txes if having a non mixable
-    const size_t max_tx_version = (hf_version < HF_VERSION_SLIPPAGE_YIELD) ? 2 : CURRENT_TRANSACTION_VERSION;
+    const size_t max_tx_version = (hf_version >= HF_VERSION_ENABLE_N_OUTS) ? TRANSACTION_VERSION_N_OUTS : TRANSACTION_VERSION_2_OUTS;
     if (tx.version > max_tx_version)
     {
       MERROR_VER("transaction version " << (unsigned)tx.version << " is higher than max accepted version " << max_tx_version);
@@ -6056,7 +6108,7 @@ void Blockchain::cancel()
 }
 
 #if defined(PER_BLOCK_CHECKPOINT)
-static const char expected_block_hashes_hash[] = "7f60b4980ea16b32e3f9fc1959d9d4116ba91f2b067bd70b3e21c44520096d14";
+static const char expected_block_hashes_hash[] = "b8639efef99951207b401131ed9f88e37c856a693d237fc6fad349b929aa1059";
 void Blockchain::load_compiled_in_block_hashes(const GetCheckpointsCallback& get_checkpoints)
 {
   if (get_checkpoints == nullptr || !m_fast_sync)

src/cryptonote_core/blockchain.h

@@ -725,6 +725,19 @@ namespace cryptonote
      */
     bool check_tx_outputs(const transaction& tx, tx_verification_context &tvc) const;
 
+    /**
+     * @brief check that a transaction's version & type conforms to current standards
+     *
+     * This function checks, for example at the time of this writing, that
+     * the TX version and type is supported by the current HF version on-chain.
+     *
+     * @param tx the transaction to check the version and type of
+     * @param tvc returned info about tx verification
+     *
+     * @return false if the TX version and/or type is unsupported, otherwise true
+     */
+    bool check_tx_type_and_version(const transaction& tx, tx_verification_context &tvc) const;
+    
     /**
      * @brief gets the block weight limit based on recent blocks
      *

src/cryptonote_core/cryptonote_core.cpp

@@ -842,8 +842,8 @@ namespace cryptonote
     }
     bad_semantics_txes_lock.unlock();
 
-    uint8_t version = m_blockchain_storage.get_current_hard_fork_version();
-    const size_t max_tx_version = (version < HF_VERSION_SLIPPAGE_YIELD) ? 2 : CURRENT_TRANSACTION_VERSION;
+    uint8_t hf_version = m_blockchain_storage.get_current_hard_fork_version();
+    const size_t max_tx_version = (hf_version >= HF_VERSION_ENABLE_N_OUTS) ? TRANSACTION_VERSION_N_OUTS : TRANSACTION_VERSION_2_OUTS;
     if (tx.version == 0 || tx.version > max_tx_version)
     {
       // v2 is the latest one we know

src/cryptonote_core/cryptonote_tx_utils.cpp

@@ -46,6 +46,11 @@ using namespace epee;
 #include "ringct/rctSigs.h"
 #include "oracle/asset_types.h"
 
+extern "C"
+{
+#include "crypto/keccak.h"
+#include "crypto/crypto-ops.h"
+}
 using namespace crypto;
 
 namespace cryptonote
@@ -583,6 +588,7 @@ namespace cryptonote
       // Different forks take a different proportion of the block_reward for stakers
       switch (hard_fork_version) {
       case HF_VERSION_BULLETPROOF_PLUS:
+      case HF_VERSION_ENABLE_N_OUTS:
         // SRCG: subtract 20% that will be rewarded to staking users
         CHECK_AND_ASSERT_MES(tx.amount_burnt == 0, false, "while creating outs: amount_burnt is nonzero");
         tx.amount_burnt = amount / 5;
@@ -653,8 +659,11 @@ namespace cryptonote
     tx.set_null();
     amount_keys.clear();
 
-    if (hf_version >= HF_VERSION_SLIPPAGE_YIELD) {
-      tx.version = 3;
+    tx.type = (tx_type == cryptonote::transaction_type::RETURN) ? cryptonote::TRANSFER : tx_type;
+
+    // Configure the correct TX version for the current HF + TX type
+    if (hf_version >= HF_VERSION_ENABLE_N_OUTS && tx.type == cryptonote::transaction_type::TRANSFER) {
+      tx.version = TRANSACTION_VERSION_N_OUTS;
     } else {
       tx.version = 2;
     }
@@ -662,8 +671,6 @@ namespace cryptonote
     tx.extra = extra;
     crypto::public_key txkey_pub;
 
-    tx.type = (tx_type == cryptonote::transaction_type::RETURN) ? cryptonote::TRANSFER : tx_type;
-
     tx.source_asset_type = source_asset;
     tx.destination_asset_type = dest_asset;
     
@@ -849,7 +856,7 @@ namespace cryptonote
     uint64_t summary_outs_money = 0;
     //fill outputs
     size_t output_index = 0;
-    size_t change_index = 0;
+    uint8_t change_index = 0;
     for(const tx_destination_entry& dst_entr: destinations)
     {
       CHECK_AND_ASSERT_MES(dst_entr.amount > 0 || tx.version > 1, false, "Destination with wrong amount: " << dst_entr.amount);
@@ -891,7 +898,7 @@ namespace cryptonote
                                            need_additional_txkeys, additional_tx_keys,
                                            additional_tx_public_keys, amount_keys, out_eph_public_key,
                                            use_view_tags, view_tag);
-
+      
       tx_out out;
       cryptonote::set_tx_out(dst_entr.amount, dst_entr.asset_type, dst_entr.is_change ? 0 : unlock_time, out_eph_public_key, use_view_tags, view_tag, out);
       tx.vout.push_back(out);
@@ -902,7 +909,51 @@ namespace cryptonote
 
     remove_field_from_tx_extra(tx.extra, typeid(tx_extra_additional_pub_keys));
 
-    if (tx.type == cryptonote::transaction_type::TRANSFER || tx.type == cryptonote::transaction_type::STAKE) {
+    if (hf_version >= HF_VERSION_ENABLE_N_OUTS && tx.type == cryptonote::transaction_type::TRANSFER) {
+      
+      // Get the output public key for the change output
+      crypto::public_key P_change = crypto::null_pkey;
+      CHECK_AND_ASSERT_MES(tx.vout.size() >= 2, false, "Internal error - too few outputs for TRANSFER tx");
+      CHECK_AND_ASSERT_MES(cryptonote::get_output_public_key(tx.vout[change_index], P_change), false, "Internal error - failed to get TX change output public key");
+      CHECK_AND_ASSERT_MES(P_change != crypto::null_pkey, false, "Internal error - not found TX change output for TRANSFER tx");
+
+      // Calculate the F points and change mask for every destination
+      for (size_t op_index=0; op_index<tx.vout.size(); ++op_index) {
+
+        // Calculate the y value for return_payment support
+        ec_scalar y;
+        struct {
+          char domain_separator[8];
+          rct::key amount_key;
+        } buf;
+        std::memset(buf.domain_separator, 0x0, sizeof(buf.domain_separator));
+        std::strncpy(buf.domain_separator, "RETURN", 7);
+        buf.amount_key = amount_keys[op_index];
+        crypto::hash_to_scalar(&buf, sizeof(buf), y);
+        
+        // Now generate the return address (and TX pubkey, although we will discard that)
+        crypto::public_key F = crypto::null_pkey;
+        crypto::public_key F_txpubkey = crypto::null_pkey;
+        CHECK_AND_ASSERT_MES(get_return_address(tx.version, tx.type, y, sender_account_keys, P_change, additional_tx_public_keys[op_index], F, F_txpubkey, hwdev), false, "Failed to get return_address");
+
+        // Push the F point into the TX vector of F points
+        tx.return_address_list.push_back(F);
+
+        // Calculate the encrypted_change_index data for this output
+        struct {
+          char domain_separator[8];
+          rct::key amount_key;
+        } eci_buf;
+        std::memset(eci_buf.domain_separator, 0x0, sizeof(buf.domain_separator));
+        std::strncpy(eci_buf.domain_separator, "CHG_IDX", 8);
+        eci_buf.amount_key = amount_keys[op_index];
+        crypto::secret_key eci_out;
+        keccak((uint8_t *)&eci_buf, sizeof(eci_buf), (uint8_t*)&eci_out, sizeof(eci_out));
+        uint8_t eci_data = change_index ^ eci_out.data[0];
+        tx.return_address_change_mask.push_back(eci_data);
+      }
+
+    } else if (tx.type == cryptonote::transaction_type::TRANSFER || tx.type == cryptonote::transaction_type::STAKE) {
 
       // Get the output public key for the change output
       crypto::public_key P_change = crypto::null_pkey;

src/cryptonote_core/cryptonote_tx_utils.h

@@ -150,6 +150,7 @@ namespace cryptonote
       FIELD(original)
       VARINT_FIELD(amount)
       FIELD(addr)
+      FIELD(asset_type)
       FIELD(is_subaddress)
       FIELD(is_integrated)
       FIELD(is_change)

src/cryptonote_core/tx_pool.cpp

@@ -259,10 +259,10 @@ namespace cryptonote
       tvc.m_invalid_output = true;
       return false;
     }
-
+    
     // Check the TX type
-    if (tx.type <= cryptonote::transaction_type::UNSET || tx.type > cryptonote::transaction_type::MAX) {
-      LOG_PRINT_L1("Transaction with id= "<< id << " has invalid type " << (uint8_t)tx.type);
+    if (!m_blockchain.check_tx_type_and_version(tx, tvc)) {
+      LOG_PRINT_L1("Transaction with id= "<< id << " has invalid type " << (uint8_t)tx.type << " and/or version " << tx.version);
       tvc.m_verifivation_failed = true;
       return false;
     }

src/cryptonote_core/tx_verification_utils.cpp

@@ -130,7 +130,7 @@ bool ver_rct_non_semantics_simple_cached
     // mixring. Future versions of the protocol may differ in this regard, but if this assumptions
     // holds true in the future, enable the verification hash by modifying the `untested_tx`
     // condition below.
-    const bool untested_tx = tx.version > 2 || tx.rct_signatures.type > rct::RCTTypeBulletproofPlus;
+    const bool untested_tx = tx.version > 3 || tx.rct_signatures.type > rct::RCTTypeBulletproofPlus;
     VER_ASSERT(!untested_tx, "Unknown TX type. Make sure RCT cache works correctly with this type and then enable it in the code here.");
 
     // Don't cache older (or newer) rctSig types

src/hardforks/hardforks.cpp

@@ -45,8 +45,8 @@ const hardfork_t testnet_hard_forks[] = {
   // version 1 from the start of the blockchain
   { 1, 1, 0, 1341378000 },
 
-  // version 2 starts from block 1000, which is on or around the 23rd of November, 2015. Fork time finalised on 2015-11-20. No fork voting occurs for the v2 fork.
-  //{ 2, 1000, 0, 1445355000 },
+  // version 2 starts from block 250
+  { 2, 250, 0, 1445355000 },
 };
 const size_t num_testnet_hard_forks = sizeof(testnet_hard_forks) / sizeof(testnet_hard_forks[0]);
 const uint64_t testnet_hard_fork_version_1_till = ((uint64_t)-1);

src/simplewallet/simplewallet.cpp

@@ -7249,7 +7249,7 @@ bool simple_wallet::locked_transfer(const std::vector<std::string> &args_)
   // TODO: add locked versions
   if (args_.size() < 2)
   {
-    PRINT_USAGE(USAGE_TRANSFER);
+    PRINT_USAGE(USAGE_LOCKED_TRANSFER);
     return true;
   }
 
@@ -8043,10 +8043,17 @@ bool simple_wallet::return_payment(const std::vector<std::string> &args_)
       return true;
     }
 
-    // Verify we have a valid return_address and tx_pubkey
-    if (td.m_tx.return_address == crypto::null_pkey || td.m_tx.return_pubkey != crypto::null_pkey) {
-      fail_msg_writer() << tr("invalid return_address/return_pubkey for txid ") << args_[0];
-      return true;
+    if (td.m_tx.version >= HF_VERSION_ENABLE_N_OUTS) {
+      if (td.m_tx.return_address_list.empty() || td.m_tx.return_address_change_mask.empty()) {
+        fail_msg_writer() << tr("invalid return_address_list for txid ") << args_[0];
+        return true;
+      }
+    } else {
+      // Verify we have a valid return_address and tx_pubkey
+      if (td.m_tx.return_address == crypto::null_pkey || td.m_tx.return_pubkey != crypto::null_pkey) {
+        fail_msg_writer() << tr("invalid return_address/return_pubkey for txid ") << args_[0];
+        return true;
+      }
     }
 
     // Check that we have the key image information, and that it is usable

src/version.cpp.in

@@ -1,5 +1,5 @@
 #define DEF_SALVIUM_VERSION_TAG "@VERSIONTAG@"
-#define DEF_SALVIUM_VERSION "0.5.2"
+#define DEF_SALVIUM_VERSION "0.5.3-rc2"
 #define DEF_MONERO_VERSION_TAG "release"
 #define DEF_MONERO_VERSION "0.18.3.3"
 #define DEF_MONERO_RELEASE_NAME "Zero"

src/wallet/wallet2.cpp

@@ -11298,8 +11298,9 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_all(uint64_t below
 
   // gather all dust and non-dust outputs of specified subaddress (if any) and below specified threshold (if any)
   bool fund_found = false;
-  for (size_t i = 0; i < m_transfers.size(); ++i)
+  for (size_t idx = 0; idx < m_transfers_indices[asset_type].size(); idx++)
   {
+    size_t i = m_transfers_indices[asset_type][idx];
     const transfer_details& td = m_transfers[i];
     if (m_ignore_fractional_outputs && td.amount() < fractional_threshold)
     {
@@ -11383,24 +11384,86 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_return(std::vector
   uint32_t priority = adjust_priority(0);
   std::vector<uint8_t> extra; // No need for a TX extra beyond that which will be calculated herein
 
+  // To return a payment, we need to know the y value to process the F value
+  // ...but the y value is calculated differently depending on the original TX
+  ec_scalar y;
+  crypto::public_key return_address = null_pkey;
+  
   // Get P_change from the TX
   crypto::public_key P_change = crypto::null_pkey;
-  size_t change_index = (td_origin.m_internal_output_index == 0) ? 1 : 0;
-  THROW_WALLET_EXCEPTION_IF(!cryptonote::get_output_public_key(td_origin.m_tx.vout[change_index], P_change), error::wallet_internal_error, "Failed to identify change output");
+  uint8_t change_index;
+  uint32_t hf_version = get_current_hard_fork();
+  if (hf_version >= HF_VERSION_ENABLE_N_OUTS && td_origin.m_tx.version >= TRANSACTION_VERSION_N_OUTS) {
 
+    // Calculate z_i (the shared secret between sender and ourselves for the original TX)
+    crypto::public_key txkey_pub = null_pkey; // R
+    const std::vector<crypto::public_key> in_additional_tx_pub_keys = get_additional_tx_pub_keys_from_extra(td_origin.m_tx);
+    if (in_additional_tx_pub_keys.size() != 0) {
+      THROW_WALLET_EXCEPTION_IF(in_additional_tx_pub_keys.size() != td_origin.m_tx.vout.size(),
+                                error::wallet_internal_error,
+                                tr("at create_transactions_return(): incorrect number of additional TX pubkeys in origin TX for return_payment"));
+      txkey_pub = in_additional_tx_pub_keys[td_origin.m_internal_output_index];
+    } else {
+      txkey_pub = get_tx_pub_key_from_extra(td_origin.m_tx);
+    }
+    crypto::key_derivation derivation = AUTO_VAL_INIT(derivation);
+    THROW_WALLET_EXCEPTION_IF(!generate_key_derivation(txkey_pub, m_account.get_keys().m_view_secret_key, derivation),
+                              error::wallet_internal_error,
+                              tr("at create_transactions_return(): failed to generate_key_derivation"));
+    crypto::secret_key z_i;
+    derivation_to_scalar(derivation, td_origin.m_internal_output_index, z_i);
+    
+    // Calculate the y value for return_payment support
+    struct {
+      char domain_separator[8];
+      rct::key amount_key;
+    } buf;
+    std::memset(buf.domain_separator, 0x0, sizeof(buf.domain_separator));
+    std::strncpy(buf.domain_separator, "RETURN", 7);
+    buf.amount_key = rct::sk2rct(z_i);
+    crypto::hash_to_scalar(&buf, sizeof(buf), y);
+        
+    // The change_index needs decoding too
+    uint8_t eci_data = td_origin.m_tx.return_address_change_mask[td_origin.m_internal_output_index];
+
+    // Calculate the encrypted_change_index data for this output
+    std::memset(buf.domain_separator, 0x0, sizeof(buf.domain_separator));
+    std::strncpy(buf.domain_separator, "CHG_IDX", 8);
+    crypto::secret_key eci_out;
+    keccak((uint8_t *)&buf, sizeof(buf), (uint8_t*)&eci_out, sizeof(eci_out));
+    change_index = eci_data ^ eci_out.data[0];
+
+    return_address = td_origin.m_tx.return_address_list[td_origin.m_internal_output_index];
+    
+  } else {
+    
+    // Calculate y
+    struct {
+      char domain_separator[8];
+      crypto::public_key pubkey;
+    } buf;
+    std::memset(buf.domain_separator, 0x0, sizeof(buf.domain_separator));
+    std::strncpy(buf.domain_separator, "RETURN", 6);
+    buf.pubkey = P_change;
+    crypto::hash_to_scalar(&buf, sizeof(buf), y);
+
+    // Change index is the one we didn't receive
+    change_index = (td_origin.m_internal_output_index == 0) ? 1 : 0;
+
+    return_address = td_origin.m_tx.return_address;
+  }
+  
+  // Sanity check that we aren't attempting to return our own TX change output to ourselves
+  THROW_WALLET_EXCEPTION_IF(change_index == td_origin.m_internal_output_index, error::wallet_internal_error, tr("Attempting to return change to ourself"));
+
+  // Sanity check that we can obtain the change output from the origin TX
+  THROW_WALLET_EXCEPTION_IF(!cryptonote::get_output_public_key(td_origin.m_tx.vout[change_index], P_change),
+                            error::wallet_internal_error,
+                            tr("Failed to identify change output"));
+  
   // Calculate yF
-  ec_scalar y;
-  struct {
-    char domain_separator[8];
-    crypto::public_key pubkey;
-  } buf;
-  std::memset(buf.domain_separator, 0x0, sizeof(buf.domain_separator));
-  std::strncpy(buf.domain_separator, "RETURN", 6);
-  buf.pubkey = P_change;
-  crypto::hash_to_scalar(&buf, sizeof(buf), y);
-
   rct::key key_y         = (rct::key&)(y);
-  rct::key key_F         = (rct::key&)(td_origin.m_tx.return_address);
+  rct::key key_F         = (rct::key&)(return_address);
   rct::key key_yF        = rct::scalarmultKey(key_F, key_y);
 
   // Build the subaddress to send the return to

src/wallet/wallet_rpc_server.cpp

@@ -392,6 +392,7 @@ namespace tools
       td.address = d.address(m_wallet->nettype(), pd.m_payment_id);
     }
 
+    entry.asset_type = pd.m_tx.source_asset_type;
     entry.type = "out";
     entry.subaddr_index = { pd.m_subaddr_account, 0 };
     for (uint32_t i: pd.m_subaddr_indices)
@@ -424,6 +425,7 @@ namespace tools
     }
 
     entry.type = is_failed ? "failed" : "pending";
+    entry.asset_type = pd.m_tx.source_asset_type;
     entry.subaddr_index = { pd.m_subaddr_account, 0 };
     for (uint32_t i: pd.m_subaddr_indices)
       entry.subaddr_indices.push_back({pd.m_subaddr_account, i});