1 files changed, 184 insertions, 0 deletions
diff --git a/src/multisig/multisig_account.cpp b/src/multisig/multisig_account.cpp
new file mode 100644
index 000000000..b7298c4b6
--- /dev/null
+++ b/src/multisig/multisig_account.cpp
@@ -0,0 +1,184 @@
+// Copyright (c) 2021, 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 "multisig_account.h"
+
+#include "crypto/crypto.h"
+#include "cryptonote_config.h"
+#include "include_base_utils.h"
+#include "multisig.h"
+#include "multisig_kex_msg.h"
+#include "ringct/rctOps.h"
+#include "ringct/rctTypes.h"
+
+#include <cstdint>
+#include <utility>
+#include <vector>
+
+
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "multisig"
+
+namespace multisig
+{
+  //----------------------------------------------------------------------------------------------------------------------
+  // multisig_account: EXTERNAL
+  //----------------------------------------------------------------------------------------------------------------------
+  multisig_account::multisig_account(const crypto::secret_key &base_privkey,
+    const crypto::secret_key &base_common_privkey) :
+      m_base_privkey{base_privkey},
+      m_base_common_privkey{base_common_privkey},
+      m_multisig_pubkey{rct::rct2pk(rct::identity())},
+      m_common_pubkey{rct::rct2pk(rct::identity())},
+      m_kex_rounds_complete{0},
+      m_next_round_kex_message{multisig_kex_msg{1, base_privkey, std::vector<crypto::public_key>{}, base_common_privkey}.get_msg()}
+  {
+    CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(m_base_privkey, m_base_pubkey),
+      "Failed to derive public key");
+  }
+  //----------------------------------------------------------------------------------------------------------------------
+  // multisig_account: EXTERNAL
+  //----------------------------------------------------------------------------------------------------------------------
+  multisig_account::multisig_account(const std::uint32_t threshold,
+    std::vector<crypto::public_key> signers,
+    const crypto::secret_key &base_privkey,
+    const crypto::secret_key &base_common_privkey,
+    std::vector<crypto::secret_key> multisig_privkeys,
+    const crypto::secret_key &common_privkey,
+    const crypto::public_key &multisig_pubkey,
+    const crypto::public_key &common_pubkey,
+    const std::uint32_t kex_rounds_complete,
+    kex_origins_map_t kex_origins_map,
+    std::string next_round_kex_message) :
+      m_base_privkey{base_privkey},
+      m_base_common_privkey{base_common_privkey},
+      m_multisig_privkeys{std::move(multisig_privkeys)},
+      m_common_privkey{common_privkey},
+      m_multisig_pubkey{multisig_pubkey},
+      m_common_pubkey{common_pubkey},
+      m_kex_rounds_complete{kex_rounds_complete},
+      m_kex_keys_to_origins_map{std::move(kex_origins_map)},
+      m_next_round_kex_message{std::move(next_round_kex_message)}
+  {
+    CHECK_AND_ASSERT_THROW_MES(kex_rounds_complete > 0, "multisig account: can't reconstruct account if its kex wasn't initialized");
+    CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(m_base_privkey, m_base_pubkey),
+      "Failed to derive public key");
+    set_multisig_config(threshold, std::move(signers));
+  }
+  //----------------------------------------------------------------------------------------------------------------------
+  // multisig_account: EXTERNAL
+  //----------------------------------------------------------------------------------------------------------------------
+  bool multisig_account::account_is_active() const
+  {
+    return m_kex_rounds_complete > 0;
+  }
+  //----------------------------------------------------------------------------------------------------------------------
+  // multisig_account: EXTERNAL
+  //----------------------------------------------------------------------------------------------------------------------
+  bool multisig_account::multisig_is_ready() const
+  {
+    if (account_is_active())
+      return multisig_kex_rounds_required(m_signers.size(), m_threshold) == m_kex_rounds_complete;
+    else
+      return false;
+  }
+    //----------------------------------------------------------------------------------------------------------------------
+  // multisig_account: INTERNAL
+  //----------------------------------------------------------------------------------------------------------------------
+  void multisig_account::set_multisig_config(const std::size_t threshold, std::vector<crypto::public_key> signers)
+  {
+    // validate
+    CHECK_AND_ASSERT_THROW_MES(threshold > 0 && threshold <= signers.size(), "multisig account: tried to set invalid threshold.");
+    CHECK_AND_ASSERT_THROW_MES(signers.size() >= 2 && signers.size() <= config::MULTISIG_MAX_SIGNERS,
+      "multisig account: tried to set invalid number of signers.");
+
+    for (auto signer_it = signers.begin(); signer_it != signers.end(); ++signer_it)
+    {
+      // signers should all be unique
+      CHECK_AND_ASSERT_THROW_MES(std::find(signers.begin(), signer_it, *signer_it) == signer_it,
+        "multisig account: tried to set signers, but found a duplicate signer unexpectedly.");
+
+      // signer pubkeys must be in main subgroup, and not identity
+      CHECK_AND_ASSERT_THROW_MES(rct::isInMainSubgroup(rct::pk2rct(*signer_it)) && !(*signer_it == rct::rct2pk(rct::identity())),
+        "multisig account: tried to set signers, but a signer pubkey is invalid.");
+    }
+
+    // own pubkey should be in signers list
+    CHECK_AND_ASSERT_THROW_MES(std::find(signers.begin(), signers.end(), m_base_pubkey) != signers.end(),
+      "multisig account: tried to set signers, but did not find the account's base pubkey in signer list.");
+
+    // sort signers
+    std::sort(signers.begin(), signers.end(),
+      [](const crypto::public_key &key1, const crypto::public_key &key2) -> bool
+        {
+          return memcmp(&key1, &key2, sizeof(crypto::public_key)) < 0;
+        }
+      );
+
+    // set
+    m_threshold = threshold;
+    m_signers = std::move(signers);
+  }
+  //----------------------------------------------------------------------------------------------------------------------
+  // multisig_account: EXTERNAL
+  //----------------------------------------------------------------------------------------------------------------------
+  void multisig_account::initialize_kex(const std::uint32_t threshold,
+    std::vector<crypto::public_key> signers,
+    const std::vector<multisig_kex_msg> &expanded_msgs_rnd1)
+  {
+    CHECK_AND_ASSERT_THROW_MES(!account_is_active(), "multisig account: tried to initialize kex, but already initialized");
+
+    // only mutate account if update succeeds
+    multisig_account temp_account{*this};
+    temp_account.set_multisig_config(threshold, std::move(signers));
+    temp_account.kex_update_impl(expanded_msgs_rnd1);
+    *this = std::move(temp_account);
+  }
+  //----------------------------------------------------------------------------------------------------------------------
+  // multisig_account: EXTERNAL
+  //----------------------------------------------------------------------------------------------------------------------
+  void multisig_account::kex_update(const std::vector<multisig_kex_msg> &expanded_msgs)
+  {
+    CHECK_AND_ASSERT_THROW_MES(account_is_active(), "multisig account: tried to update kex, but kex isn't initialized yet.");
+    CHECK_AND_ASSERT_THROW_MES(!multisig_is_ready(), "multisig account: tried to update kex, but kex is already complete.");
+
+    multisig_account temp_account{*this};
+    temp_account.kex_update_impl(expanded_msgs);
+    *this = std::move(temp_account);
+  }
+  //----------------------------------------------------------------------------------------------------------------------
+  // EXTERNAL
+  //----------------------------------------------------------------------------------------------------------------------
+  std::uint32_t multisig_kex_rounds_required(const std::uint32_t num_signers, const std::uint32_t threshold)
+  {
+    CHECK_AND_ASSERT_THROW_MES(num_signers >= threshold, "num_signers must be >= threshold");
+    CHECK_AND_ASSERT_THROW_MES(threshold >= 1, "threshold must be >= 1");
+    return num_signers - threshold + 1;
+  }
+  //----------------------------------------------------------------------------------------------------------------------
+} //namespace multisig