record blackballs as amount/offset, and add export ability

6 files changed, 283 insertions, 99 deletions

diff --git a/src/blockchain_utilities/blockchain_blackball.cpp b/src/blockchain_utilities/blockchain_blackball.cpp
index e68de9dc4..9a31b95b3 100644
--- a/src/blockchain_utilities/blockchain_blackball.cpp
+++ b/src/blockchain_utilities/blockchain_blackball.cpp
@@ -66,17 +66,17 @@ static MDB_env *env = NULL;
 struct output_data
 {
   uint64_t amount;
-  uint64_t index;
-  output_data(): amount(0), index(0) {}
-  output_data(uint64_t a, uint64_t i): amount(a), index(i) {}
-  bool operator==(const output_data &other) const { return other.amount == amount && other.index == index; }
+  uint64_t offset;
+  output_data(): amount(0), offset(0) {}
+  output_data(uint64_t a, uint64_t i): amount(a), offset(i) {}
+  bool operator==(const output_data &other) const { return other.amount == amount && other.offset == offset; }
 };
 
 //
 // relative_rings: key_image -> vector<uint64_t>
 // outputs: 128 bits -> set of key images
 // processed_txidx: string -> uint64_t
-// spent: 128 bits, zerokval
+// spent: amount -> offset
 // ring_instances: vector<uint64_t> -> uint64_t
 // stats: string -> arbitrary
 //
@@ -263,7 +263,7 @@ static void init(std::string cache_filename)
 
   dbr = mdb_dbi_open(txn, "spent", MDB_CREATE | MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED, &dbi_spent);
   CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
-  mdb_set_dupsort(txn, dbi_spent, compare_double64);
+  mdb_set_dupsort(txn, dbi_spent, compare_uint64);
 
   dbr = mdb_dbi_open(txn, "ring_instances", MDB_CREATE, &dbi_ring_instances);
   CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
@@ -511,13 +511,19 @@ static uint64_t get_num_spent_outputs()
   dbr = mdb_cursor_open(txn, dbi_spent, &cur);
   CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open cursor for spent outputs: " + std::string(mdb_strerror(dbr)));
   MDB_val k, v;
-  mdb_size_t count = 0;
-  dbr = mdb_cursor_get(cur, &k, &v, MDB_FIRST);
-  if (dbr != MDB_NOTFOUND)
+  mdb_size_t count = 0, tmp;
+
+  MDB_cursor_op op = MDB_FIRST;
+  while (1)
   {
-    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get first spent output: " + std::string(mdb_strerror(dbr)));
-    dbr = mdb_cursor_count(cur, &count);
+    dbr = mdb_cursor_get(cur, &k, &v, op);
+    op = MDB_NEXT_NODUP;
+    if (dbr == MDB_NOTFOUND)
+      break;
+    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to get first/next spent output: " + std::string(mdb_strerror(dbr)));
+    dbr = mdb_cursor_count(cur, &tmp);
     CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to count entries: " + std::string(mdb_strerror(dbr)));
+    count += tmp;
   }
 
   mdb_cursor_close(cur);
@@ -530,15 +536,17 @@ static uint64_t get_num_spent_outputs()
 
 static void add_spent_output(MDB_cursor *cur, const output_data &od)
 {
-  MDB_val v = {sizeof(od), (void*)&od};
-  int dbr = mdb_cursor_put(cur, (MDB_val *)&zerokval, &v, MDB_NODUPDATA);
+  MDB_val k = {sizeof(od.amount), (void*)&od.amount};
+  MDB_val v = {sizeof(od.offset), (void*)&od.offset};
+  int dbr = mdb_cursor_put(cur, &k, &v, 0);
   CHECK_AND_ASSERT_THROW_MES(!dbr || dbr == MDB_KEYEXIST, "Failed to add spent output: " + std::string(mdb_strerror(dbr)));
 }
 
 static bool is_output_spent(MDB_cursor *cur, const output_data &od)
 {
-  MDB_val v = {sizeof(od), (void*)&od};
-  int dbr = mdb_cursor_get(cur, (MDB_val *)&zerokval, &v, MDB_GET_BOTH);
+  MDB_val k = {sizeof(od.amount), (void*)&od.amount};
+  MDB_val v = {sizeof(od.offset), (void*)&od.offset};
+  int dbr = mdb_cursor_get(cur, &k, &v, MDB_GET_BOTH);
   CHECK_AND_ASSERT_THROW_MES(!dbr || dbr == MDB_NOTFOUND, "Failed to get spent output: " + std::string(mdb_strerror(dbr)));
   bool spent = dbr == 0;
   return spent;
@@ -562,8 +570,7 @@ static std::vector<output_data> get_spent_outputs(MDB_txn *txn)
   outs.reserve(count);
   while (1)
   {
-    const output_data *od = (const output_data*)v.mv_data;
-    outs.push_back(*od);
+    outs.push_back({*(const uint64_t*)k.mv_data, *(const uint64_t*)v.mv_data});
     dbr = mdb_cursor_get(cur, &k, &v, MDB_NEXT);
     if (dbr == MDB_NOTFOUND)
       break;
@@ -815,14 +822,6 @@ static void close_db(MDB_env *env, MDB_txn *txn, MDB_cursor *cur, MDB_dbi dbi)
   mdb_env_close(env);
 }
 
-static crypto::public_key get_output_key(MDB_cursor *cur, uint64_t amount, uint64_t offset)
-{
-  MDB_val k = { sizeof(amount), (void*)&amount }, v = { sizeof(offset), (void*)&offset };
-  int dbr = mdb_cursor_get(cur, &k, &v, MDB_GET_BOTH);
-  if (dbr) throw std::runtime_error("Output key not found: " + std::string(mdb_strerror(dbr)));
-  return *(const crypto::public_key*)(((const char*)v.mv_data) + sizeof(uint64_t) * 2);
-}
-
 static void get_num_outputs(MDB_txn *txn, MDB_cursor *cur, MDB_dbi dbi, uint64_t &pre_rct, uint64_t &rct)
 {
   uint64_t amount = 0;
@@ -884,6 +883,113 @@ static crypto::hash get_genesis_block_hash(const std::string &filename)
   return genesis_block_hash;
 }
 
+static std::vector<std::pair<uint64_t, uint64_t>> load_outputs(const std::string &filename)
+{
+  std::vector<std::pair<uint64_t, uint64_t>> outputs;
+  uint64_t amount = std::numeric_limits<uint64_t>::max();
+  FILE *f;
+
+  f = fopen(filename.c_str(), "r");
+  if (!f)
+  {
+    MERROR("Failed to load outputs from " << filename << ": " << strerror(errno));
+    return {};
+  }
+  while (1)
+  {
+    char s[256];
+    fgets(s, sizeof(s), f);
+    if (feof(f))
+      break;
+    const size_t len = strlen(s);
+    if (len > 0 && s[len - 1] == '\n')
+      s[len - 1] = 0;
+    if (!s[0])
+      continue;
+    std::pair<uint64_t, uint64_t> output;
+    uint64_t offset, num_offsets;
+    if (sscanf(s, "@%" PRIu64, &amount) == 1)
+    {
+      continue;
+    }
+    if (amount == std::numeric_limits<uint64_t>::max())
+    {
+      MERROR("Bad format in " << filename);
+      continue;
+    }
+    if (sscanf(s, "%" PRIu64 "*%" PRIu64, &offset, &num_offsets) == 2 && num_offsets < std::numeric_limits<uint64_t>::max() - offset)
+    {
+      while (num_offsets-- > 0)
+        outputs.push_back(std::make_pair(amount, offset++));
+    }
+    else if (sscanf(s, "%" PRIu64, &offset) == 1)
+    {
+      outputs.push_back(std::make_pair(amount, offset));
+    }
+    else
+    {
+      MERROR("Bad format in " << filename);
+      continue;
+    }
+  }
+  fclose(f);
+  return outputs;
+}
+
+static bool export_spent_outputs(MDB_cursor *cur, const std::string &filename)
+{
+  FILE *f = fopen(filename.c_str(), "w");
+  if (!f)
+  {
+    MERROR("Failed to open " << filename << ": " << strerror(errno));
+    return false;
+  }
+
+  uint64_t pending_amount = std::numeric_limits<uint64_t>::max();
+  std::vector<uint64_t> pending_offsets;
+  MDB_val k, v;
+  MDB_cursor_op op = MDB_FIRST;
+  while (1)
+  {
+    int dbr = mdb_cursor_get(cur, &k, &v, op);
+    if (dbr == MDB_NOTFOUND)
+      break;
+    op = MDB_NEXT;
+    if (dbr)
+    {
+      fclose(f);
+      MERROR("Failed to enumerate spent outputs: " << mdb_strerror(dbr));
+      return false;
+    }
+    const uint64_t amount = *(const uint64_t*)k.mv_data;
+    const uint64_t offset = *(const uint64_t*)v.mv_data;
+    if (!pending_offsets.empty() && (amount != pending_amount || pending_offsets.back()+1 != offset))
+    {
+      if (pending_offsets.size() == 1)
+        fprintf(f, "%" PRIu64 "\n", pending_offsets.front());
+      else
+        fprintf(f, "%" PRIu64 "*%" PRIu64 "\n", pending_offsets.front(), pending_offsets.size());
+      pending_offsets.clear();
+    }
+    if (pending_amount != amount)
+    {
+      fprintf(f, "@%" PRIu64 "\n", amount);
+      pending_amount = amount;
+    }
+    pending_offsets.push_back(offset);
+  }
+  if (!pending_offsets.empty())
+  {
+    if (pending_offsets.size() == 1)
+      fprintf(f, "%" PRIu64 "\n", pending_offsets.front());
+    else
+      fprintf(f, "%" PRIu64 "*%" PRIu64 "\n", pending_offsets.front(), pending_offsets.size());
+    pending_offsets.clear();
+  }
+  fclose(f);
+  return true;
+}
+
 int main(int argc, char* argv[])
 {
   TRY_ENTRY();
@@ -920,6 +1026,8 @@ int main(int argc, char* argv[])
   , "Specify sync option, using format [safe|fast|fastest]:[nrecords_per_sync]." 
   , "fast:1000"
   };
+  const command_line::arg_descriptor<std::string> arg_extra_spent_list = {"extra-spent-list", "Optional list of known spent outputs",""};
+  const command_line::arg_descriptor<std::string> arg_export = {"export", "Filename to export the backball list to"};
 
   command_line::add_arg(desc_cmd_sett, arg_blackball_db_dir);
   command_line::add_arg(desc_cmd_sett, arg_log_level);
@@ -928,6 +1036,8 @@ int main(int argc, char* argv[])
   command_line::add_arg(desc_cmd_sett, arg_check_subsets);
   command_line::add_arg(desc_cmd_sett, arg_verbose);
   command_line::add_arg(desc_cmd_sett, arg_db_sync_mode);
+  command_line::add_arg(desc_cmd_sett, arg_extra_spent_list);
+  command_line::add_arg(desc_cmd_sett, arg_export);
   command_line::add_arg(desc_cmd_sett, arg_inputs);
   command_line::add_arg(desc_cmd_only, command_line::arg_help);
 
@@ -967,6 +1077,9 @@ int main(int argc, char* argv[])
   bool opt_rct_only = command_line::get_arg(vm, arg_rct_only);
   bool opt_check_subsets = command_line::get_arg(vm, arg_check_subsets);
   bool opt_verbose = command_line::get_arg(vm, arg_verbose);
+  std::string opt_export = command_line::get_arg(vm, arg_export);
+  std::string extra_spent_list = command_line::get_arg(vm, arg_extra_spent_list);
+  std::vector<std::pair<uint64_t, uint64_t>> extra_spent_outputs = extra_spent_list.empty() ? std::vector<std::pair<uint64_t, uint64_t>>() : load_outputs(extra_spent_list);
 
   std::string db_type = command_line::get_arg(vm, arg_database);
   if (!cryptonote::blockchain_valid_db_type(db_type))
@@ -1015,6 +1128,36 @@ int main(int argc, char* argv[])
   MDB_cursor *cur0;
   open_db(inputs[0], &env0, &txn0, &cur0, &dbi0);
 
+  if (!extra_spent_outputs.empty())
+  {
+    MINFO("Adding " << extra_spent_outputs.size() << " extra spent outputs");
+    MDB_txn *txn;
+    int dbr = mdb_txn_begin(env, NULL, 0, &txn);
+    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
+    MDB_cursor *cur;
+    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
+    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
+
+    std::vector<std::pair<uint64_t, uint64_t>> blackballs;
+    for (const std::pair<uint64_t, uint64_t> &output: extra_spent_outputs)
+    {
+      if (!is_output_spent(cur, output_data(output.first, output.second)))
+      {
+        blackballs.push_back(output);
+        add_spent_output(cur, output_data(output.first, output.second));
+        inc_stat(txn, output.first ? "pre-rct-extra" : "rct-ring-extra");
+      }
+    }
+    if (!blackballs.empty())
+    {
+      ringdb.blackball(blackballs);
+      blackballs.clear();
+    }
+    mdb_cursor_close(cur);
+    dbr = mdb_txn_commit(txn);
+    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
+  }
+
   for (size_t n = 0; n < inputs.size(); ++n)
   {
     const std::string canonical = boost::filesystem::canonical(inputs[n]).string();
@@ -1033,7 +1176,7 @@ int main(int argc, char* argv[])
     CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
     size_t records = 0;
     const std::string filename = inputs[n];
-    std::vector<crypto::public_key> blackballs;
+    std::vector<std::pair<uint64_t, uint64_t>> blackballs;
     uint64_t n_txes;
     for_all_transactions(filename, start_idx, n_txes, [&](const cryptonote::transaction_prefix &tx)->bool
     {
@@ -1057,13 +1200,13 @@ int main(int argc, char* argv[])
         const uint64_t instances = inc_ring_instances(txn, txin.amount, new_ring);
         if (n == 0 && ring_size == 1)
         {
-          const crypto::public_key pkey = get_output_key(cur0, txin.amount, absolute[0]);
+          const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, absolute[0]);
           if (opt_verbose)
           {
-            MINFO("Blackballing output " << pkey << ", due to being used in a 1-ring");
+            MINFO("Blackballing output " << output.first << "/" << output.second << ", due to being used in a 1-ring");
             std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
           }
-          blackballs.push_back(pkey);
+          blackballs.push_back(output);
           add_spent_output(cur, output_data(txin.amount, absolute[0]));
           inc_stat(txn, txin.amount ? "pre-rct-ring-size-1" : "rct-ring-size-1");
         }
@@ -1071,13 +1214,13 @@ int main(int argc, char* argv[])
         {
           for (size_t o = 0; o < new_ring.size(); ++o)
           {
-            const crypto::public_key pkey = get_output_key(cur0, txin.amount, absolute[o]);
+            const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, absolute[o]);
             if (opt_verbose)
             {
-              MINFO("Blackballing output " << pkey << ", due to being used in " << new_ring.size() << " identical " << new_ring.size() << "-rings");
+              MINFO("Blackballing output " << output.first << "/" << output.second << ", due to being used in " << new_ring.size() << " identical " << new_ring.size() << "-rings");
               std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
             }
-            blackballs.push_back(pkey);
+            blackballs.push_back(output);
             add_spent_output(cur, output_data(txin.amount, absolute[o]));
             inc_stat(txn, txin.amount ? "pre-rct-duplicate-rings" : "rct-duplicate-rings");
           }
@@ -1086,13 +1229,13 @@ int main(int argc, char* argv[])
         {
           for (size_t o = 0; o < new_ring.size(); ++o)
           {
-            const crypto::public_key pkey = get_output_key(cur0, txin.amount, absolute[o]);
+            const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, absolute[o]);
             if (opt_verbose)
             {
-              MINFO("Blackballing output " << pkey << ", due to being used in " << new_ring.size() << " subsets of " << new_ring.size() << "-rings");
+              MINFO("Blackballing output " << output.first << "/" << output.second << ", due to being used in " << new_ring.size() << " subsets of " << new_ring.size() << "-rings");
               std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
             }
-            blackballs.push_back(pkey);
+            blackballs.push_back(output);
             add_spent_output(cur, output_data(txin.amount, absolute[o]));
             inc_stat(txn, txin.amount ? "pre-rct-subset-rings" : "rct-subset-rings");
           }
@@ -1122,13 +1265,13 @@ int main(int argc, char* argv[])
             }
             else if (common.size() == 1)
             {
-              const crypto::public_key pkey = get_output_key(cur0, txin.amount, common[0]);
+              const std::pair<uint64_t, uint64_t> output = std::make_pair(txin.amount, common[0]);
               if (opt_verbose)
               {
-                MINFO("Blackballing output " << pkey << ", due to being used in rings with a single common element");
+                MINFO("Blackballing output " << output.first << "/" << output.second << ", due to being used in rings with a single common element");
                 std::cout << "\r" << start_idx << "/" << n_txes << "         \r" << std::flush;
               }
-              blackballs.push_back(pkey);
+              blackballs.push_back(output);
               add_spent_output(cur, output_data(txin.amount, common[0]));
               inc_stat(txn, txin.amount ? "pre-rct-key-image-attack" : "rct-key-image-attack");
             }
@@ -1211,7 +1354,7 @@ int main(int argc, char* argv[])
     dbr = mdb_cursor_open(txn, dbi_spent, &cur);
     CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
 
-    std::vector<crypto::public_key> blackballs;
+    std::vector<std::pair<uint64_t, uint64_t>> blackballs;
     std::vector<output_data> scan_spent = std::move(work_spent);
     work_spent.clear();
     for (const output_data &od: scan_spent)
@@ -1234,13 +1377,13 @@ int main(int argc, char* argv[])
         }
         if (known == absolute.size() - 1)
         {
-          const crypto::public_key pkey = get_output_key(cur0, od.amount, last_unknown);
+          const std::pair<uint64_t, uint64_t> output = std::make_pair(od.amount, last_unknown);
           if (opt_verbose)
           {
-            MINFO("Blackballing output " << pkey << ", due to being used in a " <<
+            MINFO("Blackballing output " << output.first << "/" << output.second << ", due to being used in a " <<
                 absolute.size() << "-ring where all other outputs are known to be spent");
           }
-          blackballs.push_back(pkey);
+          blackballs.push_back(output);
           add_spent_output(cur, output_data(od.amount, last_unknown));
           work_spent.push_back(output_data(od.amount, last_unknown));
           inc_stat(txn, od.amount ? "pre-rct-chain-reaction" : "rct-chain-reaction");
@@ -1279,6 +1422,7 @@ skip_secondary_passes:
     { "pre-rct-duplicate-rings", pre_rct }, { "rct-duplicate-rings", rct },
     { "pre-rct-subset-rings", pre_rct }, { "rct-subset-rings", rct },
     { "pre-rct-key-image-attack", pre_rct }, { "rct-key-image-attack", rct },
+    { "pre-rct-extra", pre_rct }, { "rct-ring-extra", rct },
     { "pre-rct-chain-reaction", pre_rct }, { "rct-chain-reaction", rct },
   };
   for (const auto &key: stat_keys)
@@ -1291,6 +1435,19 @@ skip_secondary_passes:
   }
   mdb_txn_abort(txn);
 
+  if (!opt_export.empty())
+  {
+    MDB_txn *txn;
+    int dbr = mdb_txn_begin(env, NULL, 0, &txn);
+    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to create LMDB transaction: " + std::string(mdb_strerror(dbr)));
+    MDB_cursor *cur;
+    dbr = mdb_cursor_open(txn, dbi_spent, &cur);
+    CHECK_AND_ASSERT_THROW_MES(!dbr, "Failed to open LMDB cursor: " + std::string(mdb_strerror(dbr)));
+    export_spent_outputs(cur, opt_export);
+    mdb_cursor_close(cur);
+    mdb_txn_abort(txn);
+  }
+
   LOG_PRINT_L0("Blockchain blackball data exported OK");
   close_db(env0, txn0, cur0, dbi0);
   close();
diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index f5aeabded..e0e0c441a 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -1624,23 +1624,23 @@ bool simple_wallet::set_ring(const std::vector<std::string> &args)
 
 bool simple_wallet::blackball(const std::vector<std::string> &args)
 {
-  crypto::public_key output;
+  uint64_t amount = std::numeric_limits<uint64_t>::max(), offset, num_offsets;
   if (args.size() == 0)
   {
-    fail_msg_writer() << tr("usage: blackball <output_public_key> | <filename> [add]");
+    fail_msg_writer() << tr("usage: blackball <amount>/<offset> | <filename> [add]");
     return true;
   }
 
   try
   {
-    if (epee::string_tools::hex_to_pod(args[0], output))
+    if (sscanf(args[0].c_str(), "%" PRIu64 "/%" PRIu64, &amount, &offset) == 2)
     {
-      m_wallet->blackball_output(output);
+      m_wallet->blackball_output(std::make_pair(amount, offset));
     }
     else if (epee::file_io_utils::is_file_exist(args[0]))
     {
-      std::vector<crypto::public_key> outputs;
-      char str[65];
+      std::vector<std::pair<uint64_t, uint64_t>> outputs;
+      char str[256];
 
       std::unique_ptr<FILE, tools::close_file> f(fopen(args[0].c_str(), "r"));
       if (f)
@@ -1654,10 +1654,27 @@ bool simple_wallet::blackball(const std::vector<std::string> &args)
             str[len - 1] = 0;
           if (!str[0])
             continue;
-          outputs.push_back(crypto::public_key());
-          if (!epee::string_tools::hex_to_pod(str, outputs.back()))
+          if (sscanf(str, "@%" PRIu64, &amount) == 1)
           {
-            fail_msg_writer() << tr("Invalid public key: ") << str;
+            continue;
+          }
+          if (amount == std::numeric_limits<uint64_t>::max())
+          {
+            fail_msg_writer() << tr("First line is not an amount");
+            return true;
+          }
+          if (sscanf(str, "%" PRIu64 "*%" PRIu64, &offset, &num_offsets) == 2 && num_offsets <= std::numeric_limits<uint64_t>::max() - offset)
+          {
+            while (num_offsets--)
+              outputs.push_back(std::make_pair(amount, offset++));
+          }
+          else if (sscanf(str, "%" PRIu64, &offset) == 1)
+          {
+            outputs.push_back(std::make_pair(amount, offset));
+          }
+          else
+          {
+            fail_msg_writer() << tr("Invalid output: ") << str;
             return true;
           }
         }
@@ -1682,7 +1699,7 @@ bool simple_wallet::blackball(const std::vector<std::string> &args)
     }
     else
     {
-      fail_msg_writer() << tr("Invalid public key, and file doesn't exist");
+      fail_msg_writer() << tr("Invalid output key, and file doesn't exist");
       return true;
     }
   }
@@ -1696,16 +1713,16 @@ bool simple_wallet::blackball(const std::vector<std::string> &args)
 
 bool simple_wallet::unblackball(const std::vector<std::string> &args)
 {
-  crypto::public_key output;
+  std::pair<uint64_t, uint64_t> output;
   if (args.size() != 1)
   {
-    fail_msg_writer() << tr("usage: unblackball <output_public_key>");
+    fail_msg_writer() << tr("usage: unblackball <amount>/<offset>");
     return true;
   }
 
-  if (!epee::string_tools::hex_to_pod(args[0], output))
+  if (sscanf(args[0].c_str(), "%" PRIu64 "/%" PRIu64, &output.first, &output.second) != 2)
   {
-    fail_msg_writer() << tr("Invalid public key");
+    fail_msg_writer() << tr("Invalid output");
     return true;
   }
 
@@ -1723,25 +1740,25 @@ bool simple_wallet::unblackball(const std::vector<std::string> &args)
 
 bool simple_wallet::blackballed(const std::vector<std::string> &args)
 {
-  crypto::public_key output;
+  std::pair<uint64_t, uint64_t> output;
   if (args.size() != 1)
   {
-    fail_msg_writer() << tr("usage: blackballed <output_public_key>");
+    fail_msg_writer() << tr("usage: blackballed <amount>/<offset>");
     return true;
   }
 
-  if (!epee::string_tools::hex_to_pod(args[0], output))
+  if (sscanf(args[0].c_str(), "%" PRIu64 "/%" PRIu64, &output.first, &output.second) != 2)
   {
-    fail_msg_writer() << tr("Invalid public key");
+    fail_msg_writer() << tr("Invalid output");
     return true;
   }
 
   try
   {
     if (m_wallet->is_output_blackballed(output))
-      message_writer() << tr("Blackballed: ") << output;
+      message_writer() << tr("Blackballed: ") << output.first << "/" << output.second;
     else
-      message_writer() << tr("not blackballed: ") << output;
+      message_writer() << tr("not blackballed: ") << output.first << "/" << output.second;
   }
   catch (const std::exception &e)
   {
@@ -2554,15 +2571,15 @@ simple_wallet::simple_wallet()
                            tr("Save known rings to the shared rings database"));
   m_cmd_binder.set_handler("blackball",
                            boost::bind(&simple_wallet::blackball, this, _1),
-                           tr("blackball <output public key> | <filename> [add]"),
+                           tr("blackball <amount>/<offset> | <filename> [add]"),
                            tr("Blackball output(s) so they never get selected as fake outputs in a ring"));
   m_cmd_binder.set_handler("unblackball",
                            boost::bind(&simple_wallet::unblackball, this, _1),
-                           tr("unblackball <output public key>"),
+                           tr("unblackball <amount>/<offset>"),
                            tr("Unblackballs an output so it may get selected as a fake output in a ring"));
   m_cmd_binder.set_handler("blackballed",
                            boost::bind(&simple_wallet::blackballed, this, _1),
-                           tr("blackballed <output public key>"),
+                           tr("blackballed <amount>/<offset>"),
                            tr("Checks whether an output is blackballed"));
   m_cmd_binder.set_handler("version",
                            boost::bind(&simple_wallet::version, this, _1),
diff --git a/src/wallet/ringdb.cpp b/src/wallet/ringdb.cpp
index bf5478f5e..e9fc6866d 100644
--- a/src/wallet/ringdb.cpp
+++ b/src/wallet/ringdb.cpp
@@ -55,6 +55,13 @@ static int compare_hash32(const MDB_val *a, const MDB_val *b)
   return 0;
 }
 
+static int compare_uint64(const MDB_val *a, const MDB_val *b)
+{
+  const uint64_t va = *(const uint64_t*) a->mv_data;
+  const uint64_t vb = *(const uint64_t*) b->mv_data;
+  return va < vb ? -1 : va > vb;
+}
+
 static std::string compress_ring(const std::vector<uint64_t> &ring)
 {
   std::string s;
@@ -217,9 +224,9 @@ ringdb::ringdb(std::string filename, const std::string &genesis):
   THROW_WALLET_EXCEPTION_IF(dbr, tools::error::wallet_internal_error, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
   mdb_set_compare(txn, dbi_rings, compare_hash32);
 
-  dbr = mdb_dbi_open(txn, ("blackballs-" + genesis).c_str(), MDB_CREATE | MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED, &dbi_blackballs);
+  dbr = mdb_dbi_open(txn, ("blackballs2-" + genesis).c_str(), MDB_CREATE | MDB_INTEGERKEY | MDB_DUPSORT | MDB_DUPFIXED, &dbi_blackballs);
   THROW_WALLET_EXCEPTION_IF(dbr, tools::error::wallet_internal_error, "Failed to open LMDB dbi: " + std::string(mdb_strerror(dbr)));
-  mdb_set_dupsort(txn, dbi_blackballs, compare_hash32);
+  mdb_set_dupsort(txn, dbi_blackballs, compare_uint64);
 
   dbr = mdb_txn_commit(txn);
   THROW_WALLET_EXCEPTION_IF(dbr, tools::error::wallet_internal_error, "Failed to commit txn creating/opening database: " + std::string(mdb_strerror(dbr)));
@@ -374,7 +381,7 @@ bool ringdb::set_ring(const crypto::chacha_key &chacha_key, const crypto::key_im
   return true;
 }
 
-bool ringdb::blackball_worker(const std::vector<crypto::public_key> &outputs, int op)
+bool ringdb::blackball_worker(const std::vector<std::pair<uint64_t, uint64_t>> &outputs, int op)
 {
   MDB_txn *txn;
   MDB_cursor *cursor;
@@ -391,24 +398,25 @@ bool ringdb::blackball_worker(const std::vector<crypto::public_key> &outputs, in
   epee::misc_utils::auto_scope_leave_caller txn_dtor = epee::misc_utils::create_scope_leave_handler([&](){if (tx_active) mdb_txn_abort(txn);});
   tx_active = true;
 
-  MDB_val key = zerokeyval;
-  MDB_val data;
 
-  for (const crypto::public_key &output: outputs)
+  MDB_val key, data;
+  for (const std::pair<uint64_t, uint64_t> &output: outputs)
   {
-    data.mv_data = (void*)&output;
-    data.mv_size = sizeof(output);
+    key.mv_data = (void*)&output.first;
+    key.mv_size = sizeof(output.first);
+    data.mv_data = (void*)&output.second;
+    data.mv_size = sizeof(output.second);
 
     switch (op)
     {
       case BLACKBALL_BLACKBALL:
-        MDEBUG("Blackballing output " << output);
-        dbr = mdb_put(txn, dbi_blackballs, &key, &data, MDB_NODUPDATA);
+        MDEBUG("Blackballing output " << output.first << "/" << output.second);
+        dbr = mdb_put(txn, dbi_blackballs, &key, &data, MDB_APPENDDUP);
         if (dbr == MDB_KEYEXIST)
           dbr = 0;
         break;
       case BLACKBALL_UNBLACKBALL:
-        MDEBUG("Unblackballing output " << output);
+        MDEBUG("Unblackballing output " << output.first << "/" << output.second);
         dbr = mdb_del(txn, dbi_blackballs, &key, &data);
         if (dbr == MDB_NOTFOUND)
           dbr = 0;
@@ -443,32 +451,32 @@ bool ringdb::blackball_worker(const std::vector<crypto::public_key> &outputs, in
   return ret;
 }
 
-bool ringdb::blackball(const std::vector<crypto::public_key> &outputs)
+bool ringdb::blackball(const std::vector<std::pair<uint64_t, uint64_t>> &outputs)
 {
   return blackball_worker(outputs, BLACKBALL_BLACKBALL);
 }
 
-bool ringdb::blackball(const crypto::public_key &output)
+bool ringdb::blackball(const std::pair<uint64_t, uint64_t> &output)
 {
-  std::vector<crypto::public_key> outputs(1, output);
+  std::vector<std::pair<uint64_t, uint64_t>> outputs(1, output);
   return blackball_worker(outputs, BLACKBALL_BLACKBALL);
 }
 
-bool ringdb::unblackball(const crypto::public_key &output)
+bool ringdb::unblackball(const std::pair<uint64_t, uint64_t> &output)
 {
-  std::vector<crypto::public_key> outputs(1, output);
+  std::vector<std::pair<uint64_t, uint64_t>> outputs(1, output);
   return blackball_worker(outputs, BLACKBALL_UNBLACKBALL);
 }
 
-bool ringdb::blackballed(const crypto::public_key &output)
+bool ringdb::blackballed(const std::pair<uint64_t, uint64_t> &output)
 {
-  std::vector<crypto::public_key> outputs(1, output);
+  std::vector<std::pair<uint64_t, uint64_t>> outputs(1, output);
   return blackball_worker(outputs, BLACKBALL_QUERY);
 }
 
 bool ringdb::clear_blackballs()
 {
-  return blackball_worker(std::vector<crypto::public_key>(), BLACKBALL_CLEAR);
+  return blackball_worker(std::vector<std::pair<uint64_t, uint64_t>>(), BLACKBALL_CLEAR);
 }
 
 }
diff --git a/src/wallet/ringdb.h b/src/wallet/ringdb.h
index 4a78f61f8..7b448b0d7 100644
--- a/src/wallet/ringdb.h
+++ b/src/wallet/ringdb.h
@@ -49,14 +49,14 @@ namespace tools
     bool get_ring(const crypto::chacha_key &chacha_key, const crypto::key_image &key_image, std::vector<uint64_t> &outs);
     bool set_ring(const crypto::chacha_key &chacha_key, const crypto::key_image &key_image, const std::vector<uint64_t> &outs, bool relative);
 
-    bool blackball(const crypto::public_key &output);
-    bool blackball(const std::vector<crypto::public_key> &outputs);
-    bool unblackball(const crypto::public_key &output);
-    bool blackballed(const crypto::public_key &output);
+    bool blackball(const std::pair<uint64_t, uint64_t> &output);
+    bool blackball(const std::vector<std::pair<uint64_t, uint64_t>> &outputs);
+    bool unblackball(const std::pair<uint64_t, uint64_t> &output);
+    bool blackballed(const std::pair<uint64_t, uint64_t> &output);
     bool clear_blackballs();
 
   private:
-    bool blackball_worker(const std::vector<crypto::public_key> &outputs, int op);
+    bool blackball_worker(const std::vector<std::pair<uint64_t, uint64_t>> &outputs, int op);
 
   private:
     std::string filename;
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index ffd7131cd..9866aa215 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -6221,7 +6221,7 @@ bool wallet2::find_and_save_rings(bool force)
   return true;
 }
 
-bool wallet2::blackball_output(const crypto::public_key &output)
+bool wallet2::blackball_output(const std::pair<uint64_t, uint64_t> &output)
 {
   if (!m_ringdb)
     return false;
@@ -6229,7 +6229,7 @@ bool wallet2::blackball_output(const crypto::public_key &output)
   catch (const std::exception &e) { return false; }
 }
 
-bool wallet2::set_blackballed_outputs(const std::vector<crypto::public_key> &outputs, bool add)
+bool wallet2::set_blackballed_outputs(const std::vector<std::pair<uint64_t, uint64_t>> &outputs, bool add)
 {
   if (!m_ringdb)
     return false;
@@ -6244,7 +6244,7 @@ bool wallet2::set_blackballed_outputs(const std::vector<crypto::public_key> &out
   catch (const std::exception &e) { return false; }
 }
 
-bool wallet2::unblackball_output(const crypto::public_key &output)
+bool wallet2::unblackball_output(const std::pair<uint64_t, uint64_t> &output)
 {
   if (!m_ringdb)
     return false;
@@ -6252,7 +6252,7 @@ bool wallet2::unblackball_output(const crypto::public_key &output)
   catch (const std::exception &e) { return false; }
 }
 
-bool wallet2::is_output_blackballed(const crypto::public_key &output) const
+bool wallet2::is_output_blackballed(const std::pair<uint64_t, uint64_t> &output) const
 {
   if (!m_ringdb)
     return false;
@@ -6297,8 +6297,8 @@ bool wallet2::tx_add_fake_output(std::vector<std::vector<tools::wallet2::get_out
   CHECK_AND_ASSERT_MES(!outs.empty(), false, "internal error: outs is empty");
   if (std::find(outs.back().begin(), outs.back().end(), item) != outs.back().end()) // don't add duplicates
     return false;
-  if (is_output_blackballed(output_public_key)) // don't add blackballed outputs
-    return false;
+//  if (is_output_blackballed(output_public_key)) // don't add blackballed outputs
+//    return false;
   outs.back().push_back(item);
   return true;
 }
@@ -6795,6 +6795,8 @@ void wallet2::get_outs(std::vector<std::vector<tools::wallet2::get_outs_entry>>
 
           if (seen_indices.count(i))
             continue;
+          if (is_output_blackballed(std::make_pair(amount, i))) // don't add blackballed outputs
+            continue;
           seen_indices.emplace(i);
 
           LOG_PRINT_L2("picking " << i << " as " << type);
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index 556679f51..f0ed1c0e8 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -1161,10 +1161,10 @@ namespace tools
     bool set_ring(const crypto::key_image &key_image, const std::vector<uint64_t> &outs, bool relative);
     bool find_and_save_rings(bool force = true);
 
-    bool blackball_output(const crypto::public_key &output);
-    bool set_blackballed_outputs(const std::vector<crypto::public_key> &outputs, bool add = false);
-    bool unblackball_output(const crypto::public_key &output);
-    bool is_output_blackballed(const crypto::public_key &output) const;
+    bool blackball_output(const std::pair<uint64_t, uint64_t> &output);
+    bool set_blackballed_outputs(const std::vector<std::pair<uint64_t, uint64_t>> &outputs, bool add = false);
+    bool unblackball_output(const std::pair<uint64_t, uint64_t> &output);
+    bool is_output_blackballed(const std::pair<uint64_t, uint64_t> &output) const;
 
     bool lock_keys_file();
     bool unlock_keys_file();