add multisig core test and factor multisig building blocks

11 files changed, 303 insertions, 127 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index d8b0bf211..79d2a232d 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -114,6 +114,7 @@ add_subdirectory(ringct)
 add_subdirectory(checkpoints)
 add_subdirectory(cryptonote_basic)
 add_subdirectory(cryptonote_core)
+add_subdirectory(multisig)
 if(NOT IOS)
   add_subdirectory(blockchain_db)
 endif()
diff --git a/src/cryptonote_core/CMakeLists.txt b/src/cryptonote_core/CMakeLists.txt
index 169a38f0a..eeed881da 100644
--- a/src/cryptonote_core/CMakeLists.txt
+++ b/src/cryptonote_core/CMakeLists.txt
@@ -59,6 +59,7 @@ target_link_libraries(cryptonote_core
     common
     cncrypto
     blockchain_db
+    multisig
     ringct
     ${Boost_DATE_TIME_LIBRARY}
     ${Boost_PROGRAM_OPTIONS_LIBRARY}
diff --git a/src/cryptonote_core/cryptonote_tx_utils.cpp b/src/cryptonote_core/cryptonote_tx_utils.cpp
index 799c27e06..fb1f972b3 100644
--- a/src/cryptonote_core/cryptonote_tx_utils.cpp
+++ b/src/cryptonote_core/cryptonote_tx_utils.cpp
@@ -40,6 +40,7 @@ using namespace epee;
 #include "crypto/crypto.h"
 #include "crypto/hash.h"
 #include "ringct/rctSigs.h"
+#include "multisig/multisig.h"
 
 using namespace crypto;
 
@@ -72,21 +73,6 @@ namespace cryptonote
     LOG_PRINT_L2("destinations include " << num_stdaddresses << " standard addresses and " << num_subaddresses << " subaddresses");
   }
   //---------------------------------------------------------------
-  bool generate_key_image_helper_old(const account_keys& ack, const crypto::public_key& tx_public_key, size_t real_output_index, keypair& in_ephemeral, crypto::key_image& ki)
-  {
-     crypto::key_derivation recv_derivation = AUTO_VAL_INIT(recv_derivation);
-     bool r = crypto::generate_key_derivation(tx_public_key, ack.m_view_secret_key, recv_derivation);
-     CHECK_AND_ASSERT_MES(r, false, "key image helper: failed to generate_key_derivation(" << tx_public_key << ", " << ack.m_view_secret_key << ")");
-
-     r = crypto::derive_public_key(recv_derivation, real_output_index, ack.m_account_address.m_spend_public_key, in_ephemeral.pub);
-     CHECK_AND_ASSERT_MES(r, false, "key image helper: failed to derive_public_key(" << recv_derivation << ", " << real_output_index <<  ", " << ack.m_account_address.m_spend_public_key << ")");
-
-     crypto::derive_secret_key(recv_derivation, real_output_index, ack.m_spend_secret_key, in_ephemeral.sec);
-
-     crypto::generate_key_image(in_ephemeral.pub, in_ephemeral.sec, ki);
-     return true;
-  }
-  //---------------------------------------------------------------
   bool construct_miner_tx(size_t height, size_t median_size, uint64_t already_generated_coins, size_t current_block_size, uint64_t fee, const account_public_address &miner_address, transaction& tx, const blobdata& extra_nonce, size_t max_outs, uint8_t hard_fork_version) {
     tx.vin.clear();
     tx.vout.clear();
diff --git a/src/multisig/CMakeLists.txt b/src/multisig/CMakeLists.txt
new file mode 100644
index 000000000..432865ad3
--- /dev/null
+++ b/src/multisig/CMakeLists.txt
@@ -0,0 +1,52 @@
+# 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.
+
+set(multisig_sources
+  multisig.cpp)
+
+set(multisig_headers)
+
+set(multisig_private_headers
+  multisig.h)
+
+monero_private_headers(multisig
+  ${multisig_private_headers})
+
+monero_add_library(multisig
+  ${multisig_sources}
+  ${multisig_headers}
+  ${multisig_private_headers})
+
+target_link_libraries(multisig
+  PUBLIC
+    ringct
+    cryptonote_basic
+    common
+    cncrypto
+  PRIVATE
+    ${EXTRA_LIBRARIES})
diff --git a/src/multisig/multisig.cpp b/src/multisig/multisig.cpp
new file mode 100644
index 000000000..0a9933b13
--- /dev/null
+++ b/src/multisig/multisig.cpp
@@ -0,0 +1,152 @@
+// 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.
+
+#include <unordered_set>
+#include "include_base_utils.h"
+#include "crypto/crypto.h"
+#include "ringct/rctOps.h"
+#include "cryptonote_basic/account.h"
+#include "cryptonote_basic/cryptonote_format_utils.h"
+#include "multisig.h"
+
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "multisig"
+
+using namespace std;
+
+namespace cryptonote
+{
+  //-----------------------------------------------------------------
+  bool generate_key_image_helper_old(const account_keys& ack, const crypto::public_key& tx_public_key, size_t real_output_index, keypair& in_ephemeral, crypto::key_image& ki)
+  {
+    crypto::key_derivation recv_derivation = AUTO_VAL_INIT(recv_derivation);
+    bool r = crypto::generate_key_derivation(tx_public_key, ack.m_view_secret_key, recv_derivation);
+    CHECK_AND_ASSERT_MES(r, false, "key image helper: failed to generate_key_derivation(" << tx_public_key << ", " << ack.m_view_secret_key << ")");
+
+    r = crypto::derive_public_key(recv_derivation, real_output_index, ack.m_account_address.m_spend_public_key, in_ephemeral.pub);
+    CHECK_AND_ASSERT_MES(r, false, "key image helper: failed to derive_public_key(" << recv_derivation << ", " << real_output_index <<  ", " << ack.m_account_address.m_spend_public_key << ")");
+
+    crypto::derive_secret_key(recv_derivation, real_output_index, ack.m_spend_secret_key, in_ephemeral.sec);
+
+    crypto::generate_key_image(in_ephemeral.pub, in_ephemeral.sec, ki);
+    return true;
+  }
+  //-----------------------------------------------------------------
+  void generate_multisig_N_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey)
+  {
+    // the multisig spend public key is the sum of all spend public keys
+    multisig_keys.clear();
+    spend_pkey = rct::pk2rct(keys.m_account_address.m_spend_public_key);
+    for (const auto &k: spend_keys)
+      rct::addKeys(spend_pkey, spend_pkey, rct::pk2rct(k));
+    multisig_keys.push_back(keys.m_spend_secret_key);
+    spend_skey = rct::sk2rct(keys.m_spend_secret_key);
+  }
+  //-----------------------------------------------------------------
+  void generate_multisig_N1_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey)
+  {
+    multisig_keys.clear();
+    spend_pkey = rct::identity();
+    spend_skey = rct::zero();
+
+    // create all our composite private keys
+    for (const auto &k: spend_keys)
+    {
+      rct::keyV data;
+      data.push_back(rct::scalarmultKey(rct::pk2rct(k), rct::sk2rct(keys.m_spend_secret_key)));
+      static const rct::key salt = { {'M', 'u', 'l', 't' , 'i', 's', 'i', 'g' , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00  } };
+      data.push_back(salt);
+      rct::key msk = rct::hash_to_scalar(data);
+      multisig_keys.push_back(rct::rct2sk(msk));
+      sc_add(spend_skey.bytes, spend_skey.bytes, msk.bytes);
+    }
+  }
+  //-----------------------------------------------------------------
+  crypto::secret_key generate_multisig_view_secret_key(const crypto::secret_key &skey, const std::vector<crypto::secret_key> &skeys)
+  {
+    crypto::hash hash;
+    crypto::cn_fast_hash(&skey, sizeof(crypto::hash), hash);
+    rct::key view_skey = rct::hash2rct(hash);
+    for (const auto &k: skeys)
+      sc_add(view_skey.bytes, view_skey.bytes, rct::sk2rct(k).bytes);
+    return rct::rct2sk(view_skey);
+  }
+  //-----------------------------------------------------------------
+  crypto::public_key generate_multisig_N1_N_spend_public_key(const std::vector<crypto::public_key> &pkeys)
+  {
+    rct::key spend_public_key = rct::identity();
+    for (const auto &pk: pkeys)
+    {
+      rct::addKeys(spend_public_key, spend_public_key, rct::pk2rct(pk));
+    }
+    return rct::rct2pk(spend_public_key);
+  }
+  //-----------------------------------------------------------------
+  bool generate_multisig_key_image(const account_keys &keys, const crypto::public_key& tx_public_key, size_t real_output_index, cryptonote::keypair& in_ephemeral, crypto::key_image& ki, size_t multisig_key_index)
+  {
+    if (multisig_key_index >= keys.m_multisig_keys.size())
+      return false;
+    if (!cryptonote::generate_key_image_helper_old(keys, tx_public_key, real_output_index, in_ephemeral, ki))
+      return false;
+    // we got the ephemeral keypair, but the key image isn't right as it's done as per our private spend key, which is multisig
+    crypto::generate_key_image(in_ephemeral.pub, keys.m_multisig_keys[multisig_key_index], ki);
+    return true;
+  }
+  //-----------------------------------------------------------------
+  void generate_multisig_LR(const crypto::public_key pkey, const crypto::secret_key &k, crypto::public_key &L, crypto::public_key &R)
+  {
+    rct::scalarmultBase((rct::key&)L, rct::sk2rct(k));
+    crypto::generate_key_image(pkey, k, (crypto::key_image&)R);
+  }
+  //-----------------------------------------------------------------
+  bool generate_multisig_composite_key_image(const account_keys &keys, const crypto::public_key &tx_public_key, size_t real_output_index, const std::vector<crypto::key_image> &pkis, crypto::key_image &ki)
+  {
+    cryptonote::keypair in_ephemeral;
+    if (!cryptonote::generate_key_image_helper_old(keys, tx_public_key, real_output_index, in_ephemeral, ki))
+      return false;
+    std::unordered_set<crypto::key_image> used;
+    for (size_t m = 0; m < keys.m_multisig_keys.size(); ++m)
+    {
+      crypto::key_image pki;
+      bool r = cryptonote::generate_multisig_key_image(keys, tx_public_key, real_output_index, in_ephemeral, pki, m);
+      if (!r)
+        return false;
+      used.insert(pki);
+    }
+    for (const auto &pki: pkis)
+    {
+      if (used.find(pki) == used.end())
+      {
+        used.insert(pki);
+        rct::addKeys((rct::key&)ki, rct::ki2rct(ki), rct::ki2rct(pki));
+      }
+    }
+    return true;
+  }
+  //-----------------------------------------------------------------
+}
diff --git a/src/multisig/multisig.h b/src/multisig/multisig.h
new file mode 100644
index 000000000..c5312182b
--- /dev/null
+++ b/src/multisig/multisig.h
@@ -0,0 +1,50 @@
+// 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.
+
+#pragma once
+
+#include <vector>
+#include <unordered_map>
+#include "crypto/crypto.h"
+#include "cryptonote_basic/cryptonote_format_utils.h"
+#include "ringct/rctTypes.h"
+
+namespace cryptonote
+{
+  struct account_keys;
+
+  bool generate_key_image_helper_old(const account_keys& ack, const crypto::public_key& tx_public_key, size_t real_output_index, keypair& in_ephemeral, crypto::key_image& ki);
+
+  void generate_multisig_N_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey);
+  void generate_multisig_N1_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey);
+  crypto::secret_key generate_multisig_view_secret_key(const crypto::secret_key &skey, const std::vector<crypto::secret_key> &skeys);
+  crypto::public_key generate_multisig_N1_N_spend_public_key(const std::vector<crypto::public_key> &pkeys);
+  bool generate_multisig_key_image(const account_keys &keys, const crypto::public_key& tx_public_key, size_t real_output_index, cryptonote::keypair& in_ephemeral, crypto::key_image& ki, size_t multisig_key_index);
+  void generate_multisig_LR(const crypto::public_key pkey, const crypto::secret_key &k, crypto::public_key &L, crypto::public_key &R);
+  bool generate_multisig_composite_key_image(const account_keys &keys, const crypto::public_key &tx_public_key, size_t real_output_index, const std::vector<crypto::key_image> &pkis, crypto::key_image &ki);
+}
diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index ab09ace91..b0aec186c 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -868,22 +868,9 @@ bool simple_wallet::finalize_multisig(const std::vector<std::string> &args)
     return true;
   }
 
-  // parse all multisig info
-  std::unordered_set<crypto::public_key> public_keys;
-  std::vector<crypto::public_key> signers(args.size(), crypto::null_pkey);
-  for (size_t i = 0; i < args.size(); ++i)
-  {
-    if (!tools::wallet2::verify_extra_multisig_info(args[i], public_keys, signers[i]))
-    {
-      fail_msg_writer() << tr("Bad multisig info: ") << args[i];
-      return true;
-    }
-  }
-
-  // we have all pubkeys now
   try
   {
-    if (!m_wallet->finalize_multisig(orig_pwd_container->password(), public_keys, signers))
+    if (!m_wallet->finalize_multisig(orig_pwd_container->password(), args))
     {
       fail_msg_writer() << tr("Failed to finalize multisig");
       return true;
diff --git a/src/wallet/CMakeLists.txt b/src/wallet/CMakeLists.txt
index ab48bd7a2..2d664ba15 100644
--- a/src/wallet/CMakeLists.txt
+++ b/src/wallet/CMakeLists.txt
@@ -51,6 +51,7 @@ monero_add_library(wallet
   ${wallet_private_headers})
 target_link_libraries(wallet
   PUBLIC
+    multisig
     common
     cryptonote_core
     mnemonics
@@ -104,6 +105,7 @@ if (BUILD_GUI_DEPS)
     set(libs_to_merge
             wallet_api
             wallet
+            multisig
             cryptonote_core
             cryptonote_basic
             mnemonics
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 807248860..2bba6f9e1 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -46,6 +46,7 @@ using namespace epee;
 #include "rpc/core_rpc_server_commands_defs.h"
 #include "misc_language.h"
 #include "cryptonote_basic/cryptonote_basic_impl.h"
+#include "multisig/multisig.h"
 #include "common/boost_serialization_helper.h"
 #include "common/command_line.h"
 #include "common/threadpool.h"
@@ -526,24 +527,9 @@ uint8_t get_bulletproof_fork(bool testnet)
     return 255; // TODO
 }
 
-bool generate_key_image_helper_old(const account_keys& ack, const crypto::public_key& tx_public_key, size_t real_output_index, keypair& in_ephemeral, crypto::key_image& ki)
-{
-  crypto::key_derivation recv_derivation = AUTO_VAL_INIT(recv_derivation);
-  bool r = crypto::generate_key_derivation(tx_public_key, ack.m_view_secret_key, recv_derivation);
-  CHECK_AND_ASSERT_MES(r, false, "key image helper: failed to generate_key_derivation(" << tx_public_key << ", " << ack.m_view_secret_key << ")");
-
-  r = crypto::derive_public_key(recv_derivation, real_output_index, ack.m_account_address.m_spend_public_key, in_ephemeral.pub);
-  CHECK_AND_ASSERT_MES(r, false, "key image helper: failed to derive_public_key(" << recv_derivation << ", " << real_output_index <<  ", " << ack.m_account_address.m_spend_public_key << ")");
-
-  crypto::derive_secret_key(recv_derivation, real_output_index, ack.m_spend_secret_key, in_ephemeral.sec);
-
-  crypto::generate_key_image(in_ephemeral.pub, in_ephemeral.sec, ki);
-  return true;
-}
-
 bool wallet_generate_key_image_helper_old(const cryptonote::account_keys& ack, const crypto::public_key& tx_public_key, size_t real_output_index, cryptonote::keypair& in_ephemeral, crypto::key_image& ki, bool multisig_export = false)
 {
-  if (!generate_key_image_helper_old(ack, tx_public_key, real_output_index, in_ephemeral, ki))
+  if (!cryptonote::generate_key_image_helper_old(ack, tx_public_key, real_output_index, in_ephemeral, ki))
     return false;
   if (multisig_export)
   {
@@ -909,6 +895,12 @@ static uint64_t decodeRct(const rct::rctSig & rv, const crypto::key_derivation &
   }
 }
 //----------------------------------------------------------------------------------------------------
+bool wallet2::wallet_generate_key_image_helper_export(const cryptonote::account_keys& ack, const crypto::public_key& tx_public_key, size_t real_output_index, cryptonote::keypair& in_ephemeral, crypto::key_image& ki, size_t multisig_key_index) const
+{
+  THROW_WALLET_EXCEPTION_IF(multisig_key_index >= ack.m_multisig_keys.size(), error::wallet_internal_error, "Bad multisig_key_index");
+  return cryptonote::generate_multisig_key_image(ack, tx_public_key, real_output_index, in_ephemeral, ki, multisig_key_index);
+}
+//----------------------------------------------------------------------------------------------------
 void wallet2::scan_output(const cryptonote::account_keys &keys, const cryptonote::transaction &tx, const crypto::public_key &tx_pub_key, size_t i, tx_scan_info_t &tx_scan_info, int &num_vouts_received, std::unordered_map<cryptonote::subaddress_index, uint64_t> &tx_money_got_in_outs, std::vector<size_t> &outs)
 {
   bool r;
@@ -2804,29 +2796,11 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
   rct::key spend_pkey, spend_skey;
   if (threshold == spend_keys.size() + 1)
   {
-    // the multisig spend public key is the sum of all spend public keys
-    spend_pkey = rct::pk2rct(get_account().get_keys().m_account_address.m_spend_public_key);
-    for (const auto &k: spend_keys)
-      rct::addKeys(spend_pkey, spend_pkey, rct::pk2rct(k));
-    multisig_keys.push_back(get_account().get_keys().m_spend_secret_key);
-    spend_skey = rct::sk2rct(get_account().get_keys().m_spend_secret_key);
+    cryptonote::generate_multisig_N_N(get_account().get_keys(), spend_keys, multisig_keys, spend_skey, spend_pkey);
   }
   else if (threshold == spend_keys.size())
   {
-    spend_pkey = rct::identity();
-    spend_skey = rct::zero();
-
-    // create all our composite private keys
-    for (const auto &k: spend_keys)
-    {
-      rct::keyV data;
-      data.push_back(rct::scalarmultKey(rct::pk2rct(k), rct::sk2rct(get_account().get_keys().m_spend_secret_key)));
-      static const rct::key salt = { {'M', 'u', 'l', 't' , 'i', 's', 'i', 'g' , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00 , 0x00, 0x00, 0x00,0x00  } };
-      data.push_back(salt);
-      rct::key msk = rct::hash_to_scalar(data);
-      multisig_keys.push_back(rct::rct2sk(msk));
-      sc_add(spend_skey.bytes, spend_skey.bytes, msk.bytes);
-    }
+    cryptonote::generate_multisig_N1_N(get_account().get_keys(), spend_keys, multisig_keys, spend_skey, spend_pkey);
 
     // We need an extra step, so we package all the composite public keys
     // we know about, and make a signed string out of them
@@ -2856,13 +2830,10 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
 
   // the multisig view key is shared by all, make one all can derive
   MINFO("Creating view key...");
-  crypto::cn_fast_hash(&get_account().get_keys().m_view_secret_key, sizeof(crypto::secret_key), hash);
-  rct::key view_skey = rct::hash2rct(hash);
-  for (const auto &k: view_keys)
-    sc_add(view_skey.bytes, view_skey.bytes, rct::sk2rct(k).bytes);
+  crypto::secret_key view_skey = cryptonote::generate_multisig_view_secret_key(get_account().get_keys().m_view_secret_key, view_keys);
 
   MINFO("Creating multisig address...");
-  CHECK_AND_ASSERT_THROW_MES(m_account.make_multisig(rct::rct2sk(view_skey), rct::rct2sk(spend_skey), rct::rct2pk(spend_pkey), multisig_keys),
+  CHECK_AND_ASSERT_THROW_MES(m_account.make_multisig(view_skey, rct::rct2sk(spend_skey), rct::rct2pk(spend_pkey), multisig_keys),
       "Failed to create multisig wallet due to bad keys");
 
   m_account_public_address = m_account.get_keys().m_account_address;
@@ -2916,15 +2887,12 @@ bool wallet2::finalize_multisig(const epee::wipeable_string &password, std::unor
 
   CHECK_AND_ASSERT_THROW_MES(signers.size() == m_multisig_signers.size(), "Bad signers size");
 
-  rct::key spend_public_key = rct::identity();
-  for (const auto &pk: pkeys)
-  {
-    rct::addKeys(spend_public_key, spend_public_key, rct::pk2rct(pk));
-  }
+  crypto::public_key spend_public_key = cryptonote::generate_multisig_N1_N_spend_public_key(std::vector<crypto::public_key>(pkeys.begin(), pkeys.end()));
+  m_account_public_address.m_spend_public_key = spend_public_key;
+  m_account.finalize_multisig(spend_public_key);
+
   m_multisig_signers = signers;
   std::sort(m_multisig_signers.begin(), m_multisig_signers.end(), [](const crypto::public_key &e0, const crypto::public_key &e1){ return memcmp(&e0, &e1, sizeof(e0)); });
-  m_account_public_address.m_spend_public_key = rct::rct2pk(spend_public_key);
-  m_account.finalize_multisig(m_account_public_address.m_spend_public_key);
 
   if (!m_wallet_file.empty())
   {
@@ -2946,14 +2914,20 @@ bool wallet2::finalize_multisig(const epee::wipeable_string &password, std::unor
   return true;
 }
 
-bool wallet2::wallet_generate_key_image_helper_export(const cryptonote::account_keys& ack, const crypto::public_key& tx_public_key, size_t real_output_index, cryptonote::keypair& in_ephemeral, crypto::key_image& ki, size_t multisig_key_index) const
+bool wallet2::finalize_multisig(const epee::wipeable_string &password, const std::vector<std::string> &info)
 {
-  THROW_WALLET_EXCEPTION_IF(multisig_key_index >= ack.m_multisig_keys.size(), error::wallet_internal_error, "Bad multisig_key_index");
-  if (!generate_key_image_helper_old(ack, tx_public_key, real_output_index, in_ephemeral, ki))
-    return false;
-  // we got the ephemeral keypair, but the key image isn't right as it's done as per our private spend key, which is multisig
-  crypto::generate_key_image(in_ephemeral.pub, ack.m_multisig_keys[multisig_key_index], ki);
-  return true;
+  // parse all multisig info
+  std::unordered_set<crypto::public_key> public_keys;
+  std::vector<crypto::public_key> signers(info.size(), crypto::null_pkey);
+  for (size_t i = 0; i < info.size(); ++i)
+  {
+    if (!verify_extra_multisig_info(info[i], public_keys, signers[i]))
+    {
+      MERROR("Bad multisig info");
+      return false;
+    }
+  }
+  return finalize_multisig(password, public_keys, signers);
 }
 
 std::string wallet2::get_multisig_info() const
@@ -4657,7 +4631,7 @@ bool wallet2::sign_multisig_tx(multisig_tx_set &exported_txs, std::vector<crypto
   return true;
 }
 //----------------------------------------------------------------------------------------------------
-bool wallet2::sign_multisig_tx_from_file(multisig_tx_set &exported_txs, const std::string &filename, std::vector<crypto::hash> &txids)
+bool wallet2::sign_multisig_tx_to_file(multisig_tx_set &exported_txs, const std::string &filename, std::vector<crypto::hash> &txids)
 {
   bool r = sign_multisig_tx(exported_txs, txids);
   if (!r)
@@ -4684,7 +4658,7 @@ bool wallet2::sign_multisig_tx_from_file(const std::string &filename, std::vecto
     LOG_PRINT_L1("Transactions rejected by callback");
     return false;
   }
-  return sign_multisig_tx_from_file(exported_txs, filename, txids);
+  return sign_multisig_tx_to_file(exported_txs, filename, txids);
 }
 //----------------------------------------------------------------------------------------------------
 uint64_t wallet2::get_fee_multiplier(uint32_t priority, int fee_algorithm)
@@ -5591,7 +5565,7 @@ void wallet2::transfer_selected_rct(std::vector<cryptonote::tx_destination_entry
         LOG_PRINT_L2("Creating supplementary multisig transaction");
         cryptonote::transaction ms_tx;
         auto sources_copy_copy = sources_copy;
-        bool r = cryptonote::construct_tx_with_tx_key(m_account.get_keys(), m_subaddresses, sources_copy_copy, splitted_dsts, change_dts.addr, extra, ms_tx, unlock_time,tx_key, additional_tx_keys, true, &msout);
+        bool r = cryptonote::construct_tx_with_tx_key(m_account.get_keys(), m_subaddresses, sources_copy_copy, splitted_dsts, change_dts.addr, extra, ms_tx, unlock_time,tx_key, additional_tx_keys, true, bulletproof, &msout);
         LOG_PRINT_L2("constructed tx, r="<<r);
         THROW_WALLET_EXCEPTION_IF(!r, error::tx_not_constructed, sources, splitted_dsts, unlock_time, m_testnet);
         THROW_WALLET_EXCEPTION_IF(upper_transaction_size_limit <= get_object_blobsize(tx), error::tx_too_big, tx, upper_transaction_size_limit);
@@ -8357,8 +8331,7 @@ rct::multisig_kLRki wallet2::get_multisig_kLRki(size_t n, const rct::key &k) con
   CHECK_AND_ASSERT_THROW_MES(n < m_transfers.size(), "Bad m_transfers index");
   rct::multisig_kLRki kLRki;
   kLRki.k = k;
-  rct::scalarmultBase(kLRki.L, kLRki.k);
-  crypto::generate_key_image(m_transfers[n].get_public_key(), rct::rct2sk(kLRki.k), (crypto::key_image&)kLRki.R);
+  cryptonote::generate_multisig_LR(m_transfers[n].get_public_key(), rct::rct2sk(kLRki.k), (crypto::public_key&)kLRki.L, (crypto::public_key&)kLRki.R);
   kLRki.ki = rct::ki2rct(m_transfers[n].m_key_image);
   return kLRki;
 }
@@ -8399,32 +8372,13 @@ crypto::key_image wallet2::get_multisig_composite_key_image(size_t n) const
 
   const transfer_details &td = m_transfers[n];
   crypto::public_key tx_key = get_tx_pub_key_from_received_outs(td);
-  cryptonote::keypair in_ephemeral;
   crypto::key_image ki;
-  bool r = wallet_generate_key_image_helper_old(get_account().get_keys(), tx_key, td.m_internal_output_index, in_ephemeral, ki);
-  CHECK_AND_ASSERT_THROW_MES(r, "Failed to generate key image");
-  std::unordered_set<crypto::key_image> used;
-
-  // insert the ones we start from
-  for (size_t m = 0; m < get_account().get_multisig_keys().size(); ++m)
-  {
-    crypto::key_image pki;
-    wallet_generate_key_image_helper_export(get_account().get_keys(), tx_key, td.m_internal_output_index, in_ephemeral, pki, m);
-    used.insert(pki);
-  }
-
+  std::vector<crypto::key_image> pkis;
   for (const auto &info: td.m_multisig_info)
-  {
     for (const auto &pki: info.m_partial_key_images)
-    {
-      // don't add duplicates again
-      if (used.find(pki) != used.end())
-        continue;
-      used.insert(pki);
-
-      rct::addKeys((rct::key&)ki, rct::ki2rct(ki), rct::ki2rct(pki));
-    }
-  }
+      pkis.push_back(pki);
+  bool r = cryptonote::generate_multisig_composite_key_image(get_account().get_keys(), tx_key, td.m_internal_output_index, pkis, ki);
+  THROW_WALLET_EXCEPTION_IF(!r, error::wallet_internal_error, "Failed to generate key image");
   return ki;
 }
 //----------------------------------------------------------------------------------------------------
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index 5f973fef5..8abc42ff3 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -477,6 +477,10 @@ namespace tools
     /*!
      * \brief Finalizes creation of a multisig wallet
      */
+    bool finalize_multisig(const epee::wipeable_string &password, const std::vector<std::string> &info);
+    /*!
+     * \brief Finalizes creation of a multisig wallet
+     */
     bool finalize_multisig(const epee::wipeable_string &password, std::unordered_set<crypto::public_key> pkeys, std::vector<crypto::public_key> signers);
     /*!
      * Get a packaged multisig information string
@@ -642,7 +646,7 @@ namespace tools
     bool load_multisig_tx_from_file(const std::string &filename, multisig_tx_set &exported_txs, std::function<bool(const multisig_tx_set&)> accept_func = NULL);
     bool sign_multisig_tx_from_file(const std::string &filename, std::vector<crypto::hash> &txids, std::function<bool(const multisig_tx_set&)> accept_func);
     bool sign_multisig_tx(multisig_tx_set &exported_txs, std::vector<crypto::hash> &txids);
-    bool sign_multisig_tx_from_file(multisig_tx_set &exported_txs, const std::string &filename, std::vector<crypto::hash> &txids);
+    bool sign_multisig_tx_to_file(multisig_tx_set &exported_txs, const std::string &filename, std::vector<crypto::hash> &txids);
     std::vector<pending_tx> create_unmixable_sweep_transactions(bool trusted_daemon);
     bool check_connection(uint32_t *version = NULL, uint32_t timeout = 200000);
     void get_transfers(wallet2::transfer_container& incoming_transfers) const;
diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index 472302a94..ac991d861 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -2622,22 +2622,9 @@ namespace tools
       return false;
     }
 
-    // parse all multisig info
-    std::unordered_set<crypto::public_key> public_keys;
-    std::vector<crypto::public_key> signers(req.multisig_info.size(), crypto::null_pkey);
-    for (size_t i = 0; i < req.multisig_info.size(); ++i)
-    {
-      if (!m_wallet->verify_extra_multisig_info(req.multisig_info[i], public_keys, signers[i]))
-      {
-        er.code = WALLET_RPC_ERROR_CODE_BAD_MULTISIG_INFO;
-        er.message = std::string("Bad multisig_info info: ") + req.multisig_info[i];
-        return false;
-      }
-    }
-
     try
     {
-      if (!m_wallet->finalize_multisig(req.password, public_keys, signers))
+      if (!m_wallet->finalize_multisig(req.password, req.multisig_info))
       {
         er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR;
         er.message = "Error calling finalize_multisig";