add multisig core test and factor multisig building blocks

6 files changed, 716 insertions, 0 deletions

diff --git a/tests/core_tests/CMakeLists.txt b/tests/core_tests/CMakeLists.txt
index 68f2e9816..d80d62135 100644
--- a/tests/core_tests/CMakeLists.txt
+++ b/tests/core_tests/CMakeLists.txt
@@ -36,6 +36,7 @@ set(core_tests_sources
   chaingen_main.cpp
   double_spend.cpp
   integer_overflow.cpp
+  multisig.cpp
   ring_signature_1.cpp
   transaction_tests.cpp
   tx_validation.cpp
@@ -52,6 +53,7 @@ set(core_tests_headers
   double_spend.h
   double_spend.inl
   integer_overflow.h
+  multisig.h
   ring_signature_1.h
   transaction_tests.h
   tx_validation.h
@@ -63,6 +65,7 @@ add_executable(core_tests
   ${core_tests_headers})
 target_link_libraries(core_tests
   PRIVATE
+    multisig
     cryptonote_core
     p2p
     version
diff --git a/tests/core_tests/chaingen.h b/tests/core_tests/chaingen.h
index 0dcbc7f0c..939b88109 100644
--- a/tests/core_tests/chaingen.h
+++ b/tests/core_tests/chaingen.h
@@ -505,6 +505,54 @@ inline bool do_replay_file(const std::string& filename)
     cryptonote::account_base account; \
     account.generate();
 
+#define GENERATE_MULTISIG_ACCOUNT(account, threshold, total) \
+    CHECK_AND_ASSERT_MES(threshold >= 2 && threshold <= total, false, "Invalid multisig scheme"); \
+    std::vector<cryptonote::account_base> account(total); \
+    do \
+    { \
+      for (size_t msidx = 0; msidx < total; ++msidx) \
+        account[msidx].generate(); \
+      std::unordered_set<crypto::public_key> all_multisig_keys; \
+      std::vector<std::vector<crypto::secret_key>> view_keys(total); \
+      std::vector<std::vector<crypto::public_key>> spend_keys(total); \
+      for (size_t msidx = 0; msidx < total; ++msidx) \
+      { \
+        for (size_t msidx_inner = 0; msidx_inner < total; ++msidx_inner) \
+        { \
+          if (msidx_inner != msidx) \
+          { \
+            crypto::hash vkh; \
+            crypto::cn_fast_hash(&account[msidx_inner].get_keys().m_view_secret_key, sizeof(crypto::secret_key), vkh); \
+            view_keys[msidx].push_back((const crypto::secret_key&)vkh); \
+            spend_keys[msidx].push_back(account[msidx_inner].get_keys().m_account_address.m_spend_public_key); \
+          } \
+        } \
+      } \
+      for (size_t msidx = 0; msidx < total; ++msidx) \
+      { \
+        std::vector<crypto::secret_key> multisig_keys; \
+        crypto::secret_key spend_skey; \
+        crypto::public_key spend_pkey; \
+        if (threshold == total) \
+          cryptonote::generate_multisig_N_N(account[msidx].get_keys(), spend_keys[msidx], multisig_keys, (rct::key&)spend_skey, (rct::key&)spend_pkey); \
+        else \
+          cryptonote::generate_multisig_N1_N(account[msidx].get_keys(), spend_keys[msidx], multisig_keys, (rct::key&)spend_skey, (rct::key&)spend_pkey); \
+        crypto::secret_key view_skey = cryptonote::generate_multisig_view_secret_key(account[msidx].get_keys().m_view_secret_key, view_keys[msidx]); \
+        account[msidx].make_multisig(view_skey, spend_skey, spend_pkey, multisig_keys); \
+        for (const auto &k: multisig_keys) \
+          all_multisig_keys.insert(rct::rct2pk(rct::scalarmultBase(rct::sk2rct(k)))); \
+      } \
+      if (threshold < total) \
+      { \
+        std::vector<crypto::public_key> spend_public_keys; \
+        for (const auto &k: all_multisig_keys) \
+          spend_public_keys.push_back(k); \
+        crypto::public_key spend_pkey = cryptonote::generate_multisig_N1_N_spend_public_key(spend_public_keys); \
+        for (size_t msidx = 0; msidx < total; ++msidx) \
+          account[msidx].finalize_multisig(spend_pkey); \
+      } \
+    } while(0)
+
 #define MAKE_ACCOUNT(VEC_EVENTS, account) \
   cryptonote::account_base account; \
   account.generate(); \
diff --git a/tests/core_tests/chaingen_main.cpp b/tests/core_tests/chaingen_main.cpp
index 9eba347cd..a7643292b 100644
--- a/tests/core_tests/chaingen_main.cpp
+++ b/tests/core_tests/chaingen_main.cpp
@@ -199,6 +199,23 @@ int main(int argc, char* argv[])
     GENERATE_AND_PLAY(gen_rct_tx_pre_rct_altered_extra);
     GENERATE_AND_PLAY(gen_rct_tx_rct_altered_extra);
 
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_22_1_2);
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_22_2_1);
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_33_1_23);
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_33_3_21);
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_23_1_2);
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_23_1_3);
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_23_2_1);
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_23_2_3);
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_45_1_234);
+    GENERATE_AND_PLAY(gen_multisig_tx_valid_89_3_1245789);
+    GENERATE_AND_PLAY(gen_multisig_tx_invalid_23_1__no_threshold);
+    GENERATE_AND_PLAY(gen_multisig_tx_invalid_45_5_23_no_threshold);
+    GENERATE_AND_PLAY(gen_multisig_tx_invalid_22_1__no_threshold);
+    GENERATE_AND_PLAY(gen_multisig_tx_invalid_33_1__no_threshold);
+    GENERATE_AND_PLAY(gen_multisig_tx_invalid_33_1_2_no_threshold);
+    GENERATE_AND_PLAY(gen_multisig_tx_invalid_33_1_3_no_threshold);
+
     el::Level level = (failed_tests.empty() ? el::Level::Info : el::Level::Error);
     MLOG(level, "\nREPORT:");
     MLOG(level, "  Test run: " << tests_count);
diff --git a/tests/core_tests/chaingen_tests_list.h b/tests/core_tests/chaingen_tests_list.h
index 26f88dddb..b9bbf03b4 100644
--- a/tests/core_tests/chaingen_tests_list.h
+++ b/tests/core_tests/chaingen_tests_list.h
@@ -41,6 +41,7 @@
 #include "tx_validation.h"
 #include "v2_tests.h"
 #include "rct.h"
+#include "multisig.h"
 /************************************************************************/
 /*                                                                      */
 /************************************************************************/
diff --git a/tests/core_tests/multisig.cpp b/tests/core_tests/multisig.cpp
new file mode 100644
index 000000000..484b8b7ab
--- /dev/null
+++ b/tests/core_tests/multisig.cpp
@@ -0,0 +1,460 @@
+// Copyright (c) 2017, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// 
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#include "ringct/rctSigs.h"
+#include "cryptonote_basic/cryptonote_basic.h"
+#include "multisig/multisig.h"
+#include "chaingen.h"
+#include "multisig.h"
+
+using namespace epee;
+using namespace crypto;
+using namespace cryptonote;
+
+//#define NO_MULTISIG
+
+//----------------------------------------------------------------------------------------------------------------------
+// Tests
+
+bool gen_multisig_tx_validation_base::generate_with(std::vector<test_event_entry>& events,
+    int mixin, uint64_t amount_paid, bool valid,
+    size_t threshold, size_t total, size_t creator, std::vector<size_t> signers,
+    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
+{
+  uint64_t ts_start = 1338224400;
+  bool r;
+
+  CHECK_AND_ASSERT_MES(total >= 2, false, "Bad scheme");
+  CHECK_AND_ASSERT_MES(threshold <= total, false, "Bad scheme");
+  CHECK_AND_ASSERT_MES(threshold >= total - 1, false, "Unsupported scheme");
+#ifdef NO_MULTISIG
+  CHECK_AND_ASSERT_MES(total <= 5, false, "Unsupported scheme");
+#endif
+
+  // given as 1 based for clarity
+  --creator;
+  for (size_t &signer: signers)
+    --signer;
+
+  CHECK_AND_ASSERT_MES(creator < total, false, "invalid creator");
+  for (size_t signer: signers)
+    CHECK_AND_ASSERT_MES(signer < total, false, "invalid signer");
+
+#ifdef NO_MULTISIG
+  GENERATE_ACCOUNT(acc0);
+  GENERATE_ACCOUNT(acc1);
+  GENERATE_ACCOUNT(acc2);
+  GENERATE_ACCOUNT(acc3);
+  GENERATE_ACCOUNT(acc4);
+  account_base miner_account[5] = {acc0, acc1, acc2, acc3, acc4};
+#else
+  GENERATE_MULTISIG_ACCOUNT(miner_account, threshold, total);
+#endif
+
+  MAKE_GENESIS_BLOCK(events, blk_0, miner_account[creator], ts_start);
+
+  // create 8 miner accounts, and have them mine the next 8 blocks
+  // they will have a coinbase with a single out that's pseudo rct
+  const size_t n_coinbases = 8;
+  cryptonote::account_base miner_accounts[n_coinbases];
+  const cryptonote::block *prev_block = &blk_0;
+  cryptonote::block blocks[n_coinbases];
+  for (size_t n = 0; n < n_coinbases; ++n) {
+    // the first block goes to the multisig account
+    miner_accounts[n].generate();
+    account_base &account = n == 0 ? miner_account[creator] : miner_accounts[n];
+    CHECK_AND_ASSERT_MES(generator.construct_block_manually(blocks[n], *prev_block, account,
+        test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_hf_version | test_generator::bf_max_outs,
+        4, 4, prev_block->timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
+          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 1, 4),
+        false, "Failed to generate block");
+    events.push_back(blocks[n]);
+    prev_block = blocks + n;
+    LOG_PRINT_L0("Initial miner tx " << n << ": " << obj_to_json_str(blocks[n].miner_tx));
+    LOG_PRINT_L0("in block: " << obj_to_json_str(blocks[n]));
+  }
+
+  // rewind
+  cryptonote::block blk_r, blk_last;
+  {
+    blk_last = blocks[n_coinbases - 1];
+    for (size_t i = 0; i < CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW; ++i)
+    {
+      cryptonote::block blk;
+      CHECK_AND_ASSERT_MES(generator.construct_block_manually(blk, blk_last, miner_accounts[0],
+          test_generator::bf_major_ver | test_generator::bf_minor_ver | test_generator::bf_timestamp | test_generator::bf_hf_version | test_generator::bf_max_outs,
+          4, 4, blk_last.timestamp + DIFFICULTY_BLOCKS_ESTIMATE_TIMESPAN * 2, // v2 has blocks twice as long
+          crypto::hash(), 0, transaction(), std::vector<crypto::hash>(), 0, 1, 4),
+          false, "Failed to generate block");
+      events.push_back(blk);
+      blk_last = blk;
+    }
+    blk_r = blk_last;
+  }
+
+  const crypto::public_key tx_pub_key = get_tx_pub_key_from_extra(blocks[0].miner_tx);
+  MDEBUG("tx_pub_key: " << tx_pub_key);
+  const crypto::public_key output_pub_key = boost::get<txout_to_key>(blocks[0].miner_tx.vout[0].target).key;
+  MDEBUG("output_pub_key: " << output_pub_key);
+  cryptonote::keypair in_ephemeral;
+
+#ifndef NO_MULTISIG
+  // create k/L/R/ki for that output we're going to spend
+  std::vector<std::vector<crypto::secret_key>> account_k(total);
+  std::vector<std::vector<crypto::public_key>> account_L(total);
+  std::vector<std::vector<crypto::public_key>> account_R(total);
+  std::vector<std::vector<crypto::key_image>> account_ki(total);
+  for (size_t msidx = 0; msidx < total; ++msidx)
+  {
+    size_t nlr = threshold < total ? threshold - 1 : 1;
+    account_L[msidx].resize(nlr);
+    account_R[msidx].resize(nlr);
+    for (size_t n = 0; n < nlr; ++n)
+    {
+      account_k[msidx].push_back(rct::rct2sk(rct::skGen()));
+      cryptonote::generate_multisig_LR(output_pub_key, account_k[msidx][n], account_L[msidx][n], account_R[msidx][n]);
+    }
+    size_t numki = miner_account[msidx].get_multisig_keys().size();
+    account_ki[msidx].resize(numki);
+    for (size_t kiidx = 0; kiidx < numki; ++kiidx)
+    {
+      r = cryptonote::generate_multisig_key_image(miner_account[msidx].get_keys(), tx_pub_key, 0, in_ephemeral, account_ki[msidx][kiidx], kiidx);
+      CHECK_AND_ASSERT_MES(r, false, "Failed to generate multisig export key image");
+    }
+    MDEBUG("Party " << msidx << ":");
+    MDEBUG("spend: sec " << miner_account[msidx].get_keys().m_spend_secret_key << ", pub " << miner_account[msidx].get_keys().m_account_address.m_spend_public_key);
+    MDEBUG("view: sec " << miner_account[msidx].get_keys().m_view_secret_key << ", pub " << miner_account[msidx].get_keys().m_account_address.m_view_public_key);
+    for (const auto &k: miner_account[msidx].get_multisig_keys())
+      MDEBUG("msk: " << k);
+    for (size_t n = 0; n < account_k[msidx].size(); ++n)
+    {
+      MDEBUG("k: " << account_k[msidx][n]);
+      MDEBUG("L: " << account_L[msidx][n]);
+      MDEBUG("R: " << account_R[msidx][n]);
+    }
+    for (const auto &ki: account_ki[msidx])
+      MDEBUG("ki: " << ki);
+  }
+#endif
+
+  // create kLRki
+  rct::multisig_kLRki kLRki;
+#ifdef NO_MULTISIG
+  kLRki = {rct::zero(), rct::zero(), rct::zero(), rct::zero()};
+#else
+  kLRki.k = rct::sk2rct(account_k[creator][0]);
+  kLRki.L = rct::pk2rct(account_L[creator][0]);
+  kLRki.R = rct::pk2rct(account_R[creator][0]);
+  MDEBUG("Starting with k " << kLRki.k);
+  MDEBUG("Starting with L " << kLRki.L);
+  MDEBUG("Starting with R " << kLRki.R);
+  std::unordered_set<crypto::public_key> used_L;
+  for (size_t msidx = 0; msidx < total; ++msidx)
+  {
+    if (msidx == creator)
+      continue;
+    if (std::find(signers.begin(), signers.end(), msidx) == signers.end())
+      continue;
+    for (size_t lr = 0; lr < account_L[msidx].size(); ++lr)
+    {
+      if (used_L.find(account_L[msidx][lr]) == used_L.end())
+      {
+        used_L.insert(account_L[msidx][lr]);
+        MDEBUG("Adding L " << account_L[msidx][lr] << " (for k " << account_k[msidx][lr] << ")");
+        MDEBUG("Adding R " << account_R[msidx][lr]);
+        rct::addKeys((rct::key&)kLRki.L, kLRki.L, rct::pk2rct(account_L[msidx][lr]));
+        rct::addKeys((rct::key&)kLRki.R, kLRki.R, rct::pk2rct(account_R[msidx][lr]));
+        break;
+      }
+    }
+  }
+  std::vector<crypto::key_image> pkis;
+  for (size_t msidx = 0; msidx < total; ++msidx)
+    for (size_t n = 0; n < account_ki[msidx].size(); ++n)
+      pkis.push_back(account_ki[msidx][n]);
+  r = cryptonote::generate_multisig_composite_key_image(miner_account[0].get_keys(), tx_pub_key, 0, pkis, (crypto::key_image&)kLRki.ki);
+  CHECK_AND_ASSERT_MES(r, false, "Failed to generate composite key image");
+  MDEBUG("composite ki: " << kLRki.ki);
+  MDEBUG("L: " << kLRki.L);
+  MDEBUG("R: " << kLRki.R);
+  for (size_t n = 1; n < total; ++n)
+  {
+    rct::key ki;
+    r = cryptonote::generate_multisig_composite_key_image(miner_account[n].get_keys(), tx_pub_key, 0, pkis, (crypto::key_image&)ki);
+    CHECK_AND_ASSERT_MES(r, false, "Failed to generate composite key image");
+    CHECK_AND_ASSERT_MES(kLRki.ki == ki, false, "Composite key images do not match");
+  }
+#endif
+
+  // create a tx: we have 8 outputs, all from coinbase, so "fake" rct
+  std::vector<tx_source_entry> sources;
+  sources.resize(1);
+  tx_source_entry& src = sources.back();
+
+  src.real_output = 0;
+  src.amount = blocks[0].miner_tx.vout[0].amount;
+  src.real_out_tx_key = tx_pub_key;
+  src.real_output_in_tx_index = 0;
+  src.mask = rct::identity();
+  src.rct = true;
+  src.multisig_kLRki = kLRki;
+
+  for (int m = 0; m <= mixin; ++m)
+  {
+    rct::ctkey ctkey;
+    ctkey.dest = rct::pk2rct(boost::get<txout_to_key>(blocks[m].miner_tx.vout[0].target).key);
+    MDEBUG("using " << (m == 0 ? "real" : "fake") << " input " << ctkey.dest);
+    ctkey.mask = rct::commit(blocks[m].miner_tx.vout[0].amount, rct::identity()); // since those are coinbases, the masks are known
+    src.outputs.push_back(std::make_pair(m, ctkey));
+  }
+
+  //fill outputs entry
+  tx_destination_entry td;
+  td.addr = miner_account[creator].get_keys().m_account_address;
+  td.amount = amount_paid;
+  std::vector<tx_destination_entry> destinations;
+  destinations.push_back(td);
+
+  if (pre_tx)
+    pre_tx(sources, destinations);
+
+  transaction tx;
+  crypto::secret_key tx_key;
+#ifdef NO_MULTISIG
+  rct::multisig_out *msoutp = NULL;
+#else
+  rct::multisig_out msout;
+  rct::multisig_out *msoutp = &msout;
+#endif
+  std::unordered_map<crypto::public_key, cryptonote::subaddress_index> subaddresses;
+  subaddresses[miner_account[creator].get_keys().m_account_address.m_spend_public_key] = {0,0};
+  std::vector<crypto::secret_key> additional_tx_keys;
+  r = construct_tx_and_get_tx_key(miner_account[creator].get_keys(), subaddresses, sources, destinations, boost::none, std::vector<uint8_t>(), tx, 0, tx_key, additional_tx_keys, true, false, msoutp);
+  CHECK_AND_ASSERT_MES(r, false, "failed to construct transaction");
+
+#ifndef NO_MULTISIG
+  // sign
+  std::unordered_set<crypto::secret_key> used_keys;
+  const std::vector<crypto::secret_key> &msk0 = miner_account[creator].get_multisig_keys();
+  for (const auto &sk: msk0)
+    used_keys.insert(sk);
+  for (size_t signer: signers)
+  {
+    rct::key skey = rct::zero();
+    const std::vector<crypto::secret_key> &msk1 = miner_account[signer].get_multisig_keys();
+    for (size_t n = 0; n < msk1.size(); ++n)
+    {
+      const crypto::secret_key &sk1 = msk1[n];
+      if (used_keys.find(sk1) == used_keys.end())
+      {
+        used_keys.insert(sk1);
+        sc_add(skey.bytes, skey.bytes, rct::sk2rct(sk1).bytes);
+      }
+    }
+    CHECK_AND_ASSERT_MES(!(skey == rct::zero()), false, "failed to find secret multisig key to sign transaction");
+    std::vector<unsigned int> indices;
+    for (const auto &src: sources)
+      indices.push_back(src.real_output);
+    rct::keyV k;
+    k.push_back(rct::zero());
+    for (size_t n = 0; n < account_k[signer].size(); ++n)
+    {
+      crypto::public_key L;
+      rct::scalarmultBase((rct::key&)L, rct::sk2rct(account_k[signer][n]));
+      if (used_L.find(L) != used_L.end())
+      {
+        sc_add(k.back().bytes, k.back().bytes, rct::sk2rct(account_k[signer][n]).bytes);
+      }
+    }
+    CHECK_AND_ASSERT_MES(!(k.back() == rct::zero()), false, "failed to find k to sign transaction");
+
+    MDEBUG("signing with k size " << k.size());
+    MDEBUG("signing with k " << k.back());
+    MDEBUG("signing with sk " << skey);
+    for (const auto &sk: used_keys)
+      MDEBUG("  created with sk " << sk);
+    MDEBUG("signing with c size " << msout.c.size());
+    MDEBUG("signing with c " << msout.c.back());
+    r = rct::signMultisig(tx.rct_signatures, indices, k, msout, skey);
+    CHECK_AND_ASSERT_MES(r, false, "failed to sign transaction");
+  }
+#endif
+
+  // verify this tx is really to the expected address
+  const crypto::public_key tx_pub_key2 = get_tx_pub_key_from_extra(tx, 0);
+  crypto::key_derivation derivation;
+  r = crypto::generate_key_derivation(tx_pub_key2, miner_account[creator].get_keys().m_view_secret_key, derivation);
+  CHECK_AND_ASSERT_MES(r, false, "Failed to generate derivation");
+  uint64_t n_outs = 0, amount = 0;
+  std::vector<crypto::key_derivation> additional_derivations;
+  for (size_t n = 0; n < tx.vout.size(); ++n)
+  {
+    CHECK_AND_ASSERT_MES(typeid(txout_to_key) == tx.vout[n].target.type(), false, "Unexpected tx out type");
+    if (is_out_to_acc_precomp(subaddresses, boost::get<txout_to_key>(tx.vout[n].target).key, derivation, additional_derivations, n))
+    {
+      ++n_outs;
+      CHECK_AND_ASSERT_MES(tx.vout[n].amount == 0, false, "Destination amount is not zero");
+      rct::key Ctmp;
+      crypto::secret_key scalar1;
+      crypto::derivation_to_scalar(derivation, n, scalar1);
+      rct::ecdhTuple ecdh_info = tx.rct_signatures.ecdhInfo[n];
+      rct::ecdhDecode(ecdh_info, rct::sk2rct(scalar1));
+      rct::key C = tx.rct_signatures.outPk[n].mask;
+      rct::addKeys2(Ctmp, ecdh_info.mask, ecdh_info.amount, rct::H);
+      CHECK_AND_ASSERT_MES(rct::equalKeys(C, Ctmp), false, "Failed to decode amount");
+      amount += rct::h2d(ecdh_info.amount);
+    }
+  }
+  CHECK_AND_ASSERT_MES(n_outs == 1, false, "Not exactly 1 output was received");
+  CHECK_AND_ASSERT_MES(amount == amount_paid, false, "Amount paid was not the expected amount");
+
+  if (post_tx)
+    post_tx(tx);
+
+  if (!valid)
+    DO_CALLBACK(events, "mark_invalid_tx");
+  events.push_back(tx);
+  LOG_PRINT_L0("Test tx: " << obj_to_json_str(tx));
+
+  return true;
+}
+
+bool gen_multisig_tx_valid_22_1_2::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 2, 2, 1, {2}, NULL, NULL);
+}
+
+bool gen_multisig_tx_valid_22_2_1::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 2, 2, 2, {1}, NULL, NULL);
+}
+
+bool gen_multisig_tx_valid_33_1_23::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 3, 3, 1, {2, 3}, NULL, NULL);
+}
+
+bool gen_multisig_tx_valid_33_3_21::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 3, 3, 3, {2, 1}, NULL, NULL);
+}
+
+bool gen_multisig_tx_valid_23_1_2::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 2, 3, 1, {2}, NULL, NULL);
+}
+
+bool gen_multisig_tx_valid_23_1_3::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 2, 3, 1, {3}, NULL, NULL);
+}
+
+bool gen_multisig_tx_valid_23_2_1::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 2, 3, 2, {1}, NULL, NULL);
+}
+
+bool gen_multisig_tx_valid_23_2_3::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 2, 3, 2, {3}, NULL, NULL);
+}
+
+bool gen_multisig_tx_valid_45_1_234::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 4, 5, 1, {2, 3, 4}, NULL, NULL);
+}
+
+bool gen_multisig_tx_valid_89_3_1245789::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, true, 8, 9, 3, {1, 2, 4, 5, 7, 8, 9}, NULL, NULL);
+}
+
+bool gen_multisig_tx_invalid_22_1__no_threshold::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, false, 2, 2, 1, {}, NULL, NULL);
+}
+
+bool gen_multisig_tx_invalid_33_1__no_threshold::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, false, 3, 3, 1, {}, NULL, NULL);
+}
+
+bool gen_multisig_tx_invalid_33_1_2_no_threshold::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, false, 3, 3, 1, {2}, NULL, NULL);
+}
+
+bool gen_multisig_tx_invalid_33_1_3_no_threshold::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, false, 3, 3, 1, {3}, NULL, NULL);
+}
+
+bool gen_multisig_tx_invalid_23_1__no_threshold::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, false, 2, 3, 1, {}, NULL, NULL);
+}
+
+bool gen_multisig_tx_invalid_45_5_23_no_threshold::generate(std::vector<test_event_entry>& events) const
+{
+  const int mixin = 4;
+  const uint64_t amount_paid = 10000;
+  return generate_with(events, mixin, amount_paid, false, 4, 5, 5, {2, 3}, NULL, NULL);
+}
diff --git a/tests/core_tests/multisig.h b/tests/core_tests/multisig.h
new file mode 100644
index 000000000..735c3b73d
--- /dev/null
+++ b/tests/core_tests/multisig.h
@@ -0,0 +1,187 @@
+// Copyright (c) 2017, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// 
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#pragma once 
+#include "chaingen.h"
+
+struct gen_multisig_tx_validation_base : public test_chain_unit_base
+{
+  gen_multisig_tx_validation_base()
+    : m_invalid_tx_index(0)
+    , m_invalid_block_index(0)
+  {
+    REGISTER_CALLBACK_METHOD(gen_multisig_tx_validation_base, mark_invalid_tx);
+    REGISTER_CALLBACK_METHOD(gen_multisig_tx_validation_base, mark_invalid_block);
+  }
+
+  bool check_tx_verification_context(const cryptonote::tx_verification_context& tvc, bool tx_added, size_t event_idx, const cryptonote::transaction& /*tx*/)
+  {
+    if (m_invalid_tx_index == event_idx)
+      return tvc.m_verifivation_failed;
+    else
+      return !tvc.m_verifivation_failed && tx_added;
+  }
+
+  bool check_block_verification_context(const cryptonote::block_verification_context& bvc, size_t event_idx, const cryptonote::block& /*block*/)
+  {
+    if (m_invalid_block_index == event_idx)
+      return bvc.m_verifivation_failed;
+    else
+      return !bvc.m_verifivation_failed;
+  }
+
+  bool mark_invalid_block(cryptonote::core& /*c*/, size_t ev_index, const std::vector<test_event_entry>& /*events*/)
+  {
+    m_invalid_block_index = ev_index + 1;
+    return true;
+  }
+
+  bool mark_invalid_tx(cryptonote::core& /*c*/, size_t ev_index, const std::vector<test_event_entry>& /*events*/)
+  {
+    m_invalid_tx_index = ev_index + 1;
+    return true;
+  }
+
+  bool generate_with(std::vector<test_event_entry>& events, int mixin,
+      uint64_t amount_paid, bool valid,
+      size_t threshold, size_t total, size_t creator, std::vector<size_t> signers,
+      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;
+
+private:
+  size_t m_invalid_tx_index;
+  size_t m_invalid_block_index;
+};
+
+template<>
+struct get_test_options<gen_multisig_tx_validation_base> {
+  const std::pair<uint8_t, uint64_t> hard_forks[3] = {std::make_pair(1, 0), std::make_pair(4, 1), std::make_pair(0, 0)};
+  const cryptonote::test_options test_options = {
+    hard_forks
+  };
+};
+
+// valid
+struct gen_multisig_tx_valid_22_1_2: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_valid_22_1_2>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_valid_22_2_1: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_valid_22_2_1>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_valid_33_1_23: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_valid_33_1_23>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_valid_33_3_21: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_valid_33_3_21>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_valid_23_1_2: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_valid_23_1_2>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_valid_23_1_3: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_valid_23_1_3>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_valid_23_2_1: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_valid_23_2_1>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_valid_23_2_3: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_valid_23_2_3>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_valid_45_1_234: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+
+template<> struct get_test_options<gen_multisig_tx_valid_45_1_234>: public get_test_options<gen_multisig_tx_validation_base> {};
+struct gen_multisig_tx_valid_89_3_1245789: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_valid_89_3_1245789>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+// invalid
+struct gen_multisig_tx_invalid_22_1__no_threshold: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_invalid_22_1__no_threshold>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_invalid_33_1__no_threshold: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_invalid_33_1__no_threshold>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_invalid_33_1_2_no_threshold: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_invalid_33_1_2_no_threshold>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_invalid_33_1_3_no_threshold: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_invalid_33_1_3_no_threshold>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_invalid_23_1__no_threshold: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_invalid_23_1__no_threshold>: public get_test_options<gen_multisig_tx_validation_base> {};
+
+struct gen_multisig_tx_invalid_45_5_23_no_threshold: public gen_multisig_tx_validation_base
+{
+  bool generate(std::vector<test_event_entry>& events) const;
+};
+template<> struct get_test_options<gen_multisig_tx_invalid_45_5_23_no_threshold>: public get_test_options<gen_multisig_tx_validation_base> {};