From 743dd0e3b49582b802ddc552c20fb97fc26738d8 Mon Sep 17 00:00:00 2001 From: koe Date: Mon, 2 Aug 2021 23:27:43 -0500 Subject: [PATCH] multisig key exchange update and refactor --- src/crypto/crypto.h | 11 +- src/cryptonote_basic/account.cpp | 5 - src/cryptonote_basic/account.h | 1 - .../cryptonote_format_utils.cpp | 21 +- src/cryptonote_config.h | 4 + src/cryptonote_core/cryptonote_tx_utils.cpp | 1 - src/gen_multisig/gen_multisig.cpp | 42 +- src/multisig/CMakeLists.txt | 9 +- src/multisig/multisig.cpp | 168 ++-- src/multisig/multisig.h | 70 +- src/multisig/multisig_account.cpp | 184 +++++ src/multisig/multisig_account.h | 246 ++++++ src/multisig/multisig_account_kex_impl.cpp | 726 ++++++++++++++++++ src/multisig/multisig_kex_msg.cpp | 292 +++++++ src/multisig/multisig_kex_msg.h | 109 +++ src/multisig/multisig_kex_msg_serialization.h | 78 ++ src/simplewallet/simplewallet.cpp | 63 +- src/simplewallet/simplewallet.h | 1 - src/wallet/api/wallet.cpp | 24 +- src/wallet/api/wallet.h | 1 - src/wallet/api/wallet2_api.h | 8 +- src/wallet/wallet2.cpp | 602 ++++----------- src/wallet/wallet2.h | 46 +- src/wallet/wallet_rpc_server.cpp | 54 +- src/wallet/wallet_rpc_server_commands_defs.h | 9 +- tests/core_tests/chaingen.h | 2 +- tests/core_tests/multisig.cpp | 132 ++-- tests/functional_tests/multisig.py | 29 +- tests/unit_tests/multisig.cpp | 232 +++++- utils/python-rpc/framework/wallet.py | 6 +- 30 files changed, 2225 insertions(+), 951 deletions(-) create mode 100644 src/multisig/multisig_account.cpp create mode 100644 src/multisig/multisig_account.h create mode 100644 src/multisig/multisig_account_kex_impl.cpp create mode 100644 src/multisig/multisig_kex_msg.cpp create mode 100644 src/multisig/multisig_kex_msg.h create mode 100644 src/multisig/multisig_kex_msg_serialization.h diff --git a/src/crypto/crypto.h b/src/crypto/crypto.h index 7ddc0150f..599ae4f91 100644 --- a/src/crypto/crypto.h +++ b/src/crypto/crypto.h @@ -64,6 +64,11 @@ namespace crypto { friend class crypto_ops; }; + POD_CLASS public_key_memsafe : epee::mlocked> { + public_key_memsafe() = default; + public_key_memsafe(const public_key &original) { memcpy(this->data, original.data, 32); } + }; + using secret_key = epee::mlocked>; POD_CLASS public_keyV { @@ -100,7 +105,7 @@ namespace crypto { void random32_unbiased(unsigned char *bytes); static_assert(sizeof(ec_point) == 32 && sizeof(ec_scalar) == 32 && - sizeof(public_key) == 32 && sizeof(secret_key) == 32 && + sizeof(public_key) == 32 && sizeof(public_key_memsafe) == 32 && sizeof(secret_key) == 32 && sizeof(key_derivation) == 32 && sizeof(key_image) == 32 && sizeof(signature) == 64, "Invalid structure size"); @@ -310,9 +315,13 @@ namespace crypto { const extern crypto::public_key null_pkey; const extern crypto::secret_key null_skey; + + inline bool operator<(const public_key &p1, const public_key &p2) { return memcmp(&p1, &p2, sizeof(public_key)) < 0; } + inline bool operator>(const public_key &p1, const public_key &p2) { return p2 < p1; } } CRYPTO_MAKE_HASHABLE(public_key) CRYPTO_MAKE_HASHABLE_CONSTANT_TIME(secret_key) +CRYPTO_MAKE_HASHABLE_CONSTANT_TIME(public_key_memsafe) CRYPTO_MAKE_HASHABLE(key_image) CRYPTO_MAKE_COMPARABLE(signature) diff --git a/src/cryptonote_basic/account.cpp b/src/cryptonote_basic/account.cpp index 36ff41684..9927351a9 100644 --- a/src/cryptonote_basic/account.cpp +++ b/src/cryptonote_basic/account.cpp @@ -253,11 +253,6 @@ DISABLE_VS_WARNINGS(4244 4345) return crypto::secret_key_to_public_key(view_secret_key, m_keys.m_account_address.m_view_public_key); } //----------------------------------------------------------------- - void account_base::finalize_multisig(const crypto::public_key &spend_public_key) - { - m_keys.m_account_address.m_spend_public_key = spend_public_key; - } - //----------------------------------------------------------------- const account_keys& account_base::get_keys() const { return m_keys; diff --git a/src/cryptonote_basic/account.h b/src/cryptonote_basic/account.h index 5288b9b04..96b024c3c 100644 --- a/src/cryptonote_basic/account.h +++ b/src/cryptonote_basic/account.h @@ -82,7 +82,6 @@ namespace cryptonote void create_from_keys(const cryptonote::account_public_address& address, const crypto::secret_key& spendkey, const crypto::secret_key& viewkey); void create_from_viewkey(const cryptonote::account_public_address& address, const crypto::secret_key& viewkey); bool make_multisig(const crypto::secret_key &view_secret_key, const crypto::secret_key &spend_secret_key, const crypto::public_key &spend_public_key, const std::vector &multisig_keys); - void finalize_multisig(const crypto::public_key &spend_public_key); const account_keys& get_keys() const; std::string get_public_address_str(network_type nettype) const; std::string get_public_integrated_address_str(const crypto::hash8 &payment_id, network_type nettype) const; diff --git a/src/cryptonote_basic/cryptonote_format_utils.cpp b/src/cryptonote_basic/cryptonote_format_utils.cpp index 24d605c9b..3d64053d3 100644 --- a/src/cryptonote_basic/cryptonote_format_utils.cpp +++ b/src/cryptonote_basic/cryptonote_format_utils.cpp @@ -314,7 +314,26 @@ namespace cryptonote { // derive secret key with subaddress - step 1: original CN derivation crypto::secret_key scalar_step1; - hwdev.derive_secret_key(recv_derivation, real_output_index, ack.m_spend_secret_key, scalar_step1); // computes Hs(a*R || idx) + b + crypto::secret_key spend_skey = crypto::null_skey; + + if (ack.m_multisig_keys.empty()) + { + // if not multisig, use normal spend skey + spend_skey = ack.m_spend_secret_key; + } + else + { + // if multisig, use sum of multisig privkeys (local account's share of aggregate spend key) + for (const auto &multisig_key : ack.m_multisig_keys) + { + sc_add((unsigned char*)spend_skey.data, + (const unsigned char*)multisig_key.data, + (const unsigned char*)spend_skey.data); + } + } + + // computes Hs(a*R || idx) + b + hwdev.derive_secret_key(recv_derivation, real_output_index, spend_skey, scalar_step1); // step 2: add Hs(a || index_major || index_minor) crypto::secret_key subaddr_sk; diff --git a/src/cryptonote_config.h b/src/cryptonote_config.h index 2cb28b2b1..80534fbc0 100644 --- a/src/cryptonote_config.h +++ b/src/cryptonote_config.h @@ -230,12 +230,16 @@ namespace config const unsigned char HASH_KEY_RPC_PAYMENT_NONCE = 0x58; const unsigned char HASH_KEY_MEMORY = 'k'; const unsigned char HASH_KEY_MULTISIG[] = {'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 }; + const unsigned char HASH_KEY_MULTISIG_KEY_AGGREGATION[] = "Multisig_key_agg"; const unsigned char HASH_KEY_TXPROOF_V2[] = "TXPROOF_V2"; const unsigned char HASH_KEY_CLSAG_ROUND[] = "CLSAG_round"; const unsigned char HASH_KEY_CLSAG_AGG_0[] = "CLSAG_agg_0"; const unsigned char HASH_KEY_CLSAG_AGG_1[] = "CLSAG_agg_1"; const char HASH_KEY_MESSAGE_SIGNING[] = "MoneroMessageSignature"; + // Multisig + const uint32_t MULTISIG_MAX_SIGNERS{16}; + namespace testnet { uint64_t const CRYPTONOTE_PUBLIC_ADDRESS_BASE58_PREFIX = 53; diff --git a/src/cryptonote_core/cryptonote_tx_utils.cpp b/src/cryptonote_core/cryptonote_tx_utils.cpp index cee10e198..b165e1091 100644 --- a/src/cryptonote_core/cryptonote_tx_utils.cpp +++ b/src/cryptonote_core/cryptonote_tx_utils.cpp @@ -43,7 +43,6 @@ using namespace epee; #include "crypto/crypto.h" #include "crypto/hash.h" #include "ringct/rctSigs.h" -#include "multisig/multisig.h" using namespace crypto; diff --git a/src/gen_multisig/gen_multisig.cpp b/src/gen_multisig/gen_multisig.cpp index 15f7e5c0a..014287cc5 100644 --- a/src/gen_multisig/gen_multisig.cpp +++ b/src/gen_multisig/gen_multisig.cpp @@ -97,55 +97,35 @@ static bool generate_multisig(uint32_t threshold, uint32_t total, const std::str } // gather the keys - std::vector sk(total); - std::vector pk(total); + std::vector first_round_msgs; + first_round_msgs.reserve(total); for (size_t n = 0; n < total; ++n) { wallets[n]->decrypt_keys(pwd_container->password()); - if (!tools::wallet2::verify_multisig_info(wallets[n]->get_multisig_info(), sk[n], pk[n])) - { - tools::fail_msg_writer() << genms::tr("Failed to verify multisig info"); - return false; - } + + first_round_msgs.emplace_back(wallets[n]->get_multisig_first_kex_msg()); + wallets[n]->encrypt_keys(pwd_container->password()); } // make the wallets multisig - std::vector extra_info(total); + std::vector kex_msgs_intermediate(total); std::stringstream ss; for (size_t n = 0; n < total; ++n) { std::string name = basename + "-" + std::to_string(n + 1); - std::vector skn; - std::vector pkn; - for (size_t k = 0; k < total; ++k) - { - if (k != n) - { - skn.push_back(sk[k]); - pkn.push_back(pk[k]); - } - } - extra_info[n] = wallets[n]->make_multisig(pwd_container->password(), skn, pkn, threshold); + + kex_msgs_intermediate[n] = wallets[n]->make_multisig(pwd_container->password(), first_round_msgs, threshold); + ss << " " << name << std::endl; } //exchange keys unless exchange_multisig_keys returns no extra info - while (!extra_info[0].empty()) + while (!kex_msgs_intermediate[0].empty()) { - std::unordered_set pkeys; - std::vector signers(total); for (size_t n = 0; n < total; ++n) { - if (!tools::wallet2::verify_extra_multisig_info(extra_info[n], pkeys, signers[n])) - { - tools::fail_msg_writer() << genms::tr("Error verifying multisig extra info"); - return false; - } - } - for (size_t n = 0; n < total; ++n) - { - extra_info[n] = wallets[n]->exchange_multisig_keys(pwd_container->password(), pkeys, signers); + kex_msgs_intermediate[n] = wallets[n]->exchange_multisig_keys(pwd_container->password(), kex_msgs_intermediate); } } diff --git a/src/multisig/CMakeLists.txt b/src/multisig/CMakeLists.txt index eaa2c6f71..14099e64a 100644 --- a/src/multisig/CMakeLists.txt +++ b/src/multisig/CMakeLists.txt @@ -27,12 +27,17 @@ # THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. set(multisig_sources - multisig.cpp) + multisig.cpp + multisig_account.cpp + multisig_account_kex_impl.cpp + multisig_kex_msg.cpp) set(multisig_headers) set(multisig_private_headers - multisig.h) + multisig.h + multisig_account.h + multisig_kex_msg.h) monero_private_headers(multisig ${multisig_private_headers}) diff --git a/src/multisig/multisig.cpp b/src/multisig/multisig.cpp index 272de73b2..85c45bc31 100644 --- a/src/multisig/multisig.cpp +++ b/src/multisig/multisig.cpp @@ -1,4 +1,4 @@ -// Copyright (c) 2017-2020, The Monero Project +// Copyright (c) 2017-2021, The Monero Project // // All rights reserved. // @@ -26,29 +26,34 @@ // 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 -#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" #include "cryptonote_config.h" +#include "include_base_utils.h" +#include "multisig.h" +#include "ringct/rctOps.h" + +#include +#include +#include +#include #undef MONERO_DEFAULT_LOG_CATEGORY #define MONERO_DEFAULT_LOG_CATEGORY "multisig" -using namespace std; - -namespace cryptonote +namespace multisig { - //----------------------------------------------------------------- + //---------------------------------------------------------------------------------------------------------------------- crypto::secret_key get_multisig_blinded_secret_key(const crypto::secret_key &key) { + CHECK_AND_ASSERT_THROW_MES(key != crypto::null_skey, "Unexpected null secret key (danger!)."); + rct::key multisig_salt; static_assert(sizeof(rct::key) == sizeof(config::HASH_KEY_MULTISIG), "Hash domain separator is an unexpected size"); memcpy(multisig_salt.bytes, config::HASH_KEY_MULTISIG, sizeof(rct::key)); + // private key = H(key, domain-sep) rct::keyV data; data.reserve(2); data.push_back(rct::sk2rct(key)); @@ -57,134 +62,79 @@ namespace cryptonote memwipe(&data[0], sizeof(rct::key)); return result; } - //----------------------------------------------------------------- - void generate_multisig_N_N(const account_keys &keys, const std::vector &spend_keys, std::vector &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(); - const crypto::secret_key spend_secret_key = get_multisig_blinded_secret_key(keys.m_spend_secret_key); - CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(spend_secret_key, (crypto::public_key&)spend_pkey), "Failed to derive public key"); - for (const auto &k: spend_keys) - rct::addKeys(spend_pkey, spend_pkey, rct::pk2rct(k)); - multisig_keys.push_back(spend_secret_key); - spend_skey = rct::sk2rct(spend_secret_key); - } - //----------------------------------------------------------------- - void generate_multisig_N1_N(const account_keys &keys, const std::vector &spend_keys, std::vector &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 - crypto::secret_key blinded_skey = get_multisig_blinded_secret_key(keys.m_spend_secret_key); - for (const auto &k: spend_keys) - { - rct::key sk = rct::scalarmultKey(rct::pk2rct(k), rct::sk2rct(blinded_skey)); - crypto::secret_key msk = get_multisig_blinded_secret_key(rct::rct2sk(sk)); - memwipe(&sk, sizeof(sk)); - multisig_keys.push_back(msk); - sc_add(spend_skey.bytes, spend_skey.bytes, (const unsigned char*)msk.data); - } - } - //----------------------------------------------------------------- - std::vector generate_multisig_derivations(const account_keys &keys, const std::vector &derivations) - { - std::vector multisig_keys; - crypto::secret_key blinded_skey = get_multisig_blinded_secret_key(keys.m_spend_secret_key); - for (const auto &k: derivations) - { - rct::key d = rct::scalarmultKey(rct::pk2rct(k), rct::sk2rct(blinded_skey)); - multisig_keys.push_back(rct::rct2pk(d)); - } - - return multisig_keys; - } - //----------------------------------------------------------------- - crypto::secret_key calculate_multisig_signer_key(const std::vector& multisig_keys) - { - rct::key secret_key = rct::zero(); - for (const auto &k: multisig_keys) - { - sc_add(secret_key.bytes, secret_key.bytes, (const unsigned char*)k.data); - } - - return rct::rct2sk(secret_key); - } - //----------------------------------------------------------------- - std::vector calculate_multisig_keys(const std::vector& derivations) - { - std::vector multisig_keys; - multisig_keys.reserve(derivations.size()); - - for (const auto &k: derivations) - { - multisig_keys.emplace_back(get_multisig_blinded_secret_key(rct::rct2sk(rct::pk2rct(k)))); - } - - return multisig_keys; - } - //----------------------------------------------------------------- - crypto::secret_key generate_multisig_view_secret_key(const crypto::secret_key &skey, const std::vector &skeys) - { - crypto::secret_key view_skey = get_multisig_blinded_secret_key(skey); - for (const auto &k: skeys) - sc_add((unsigned char*)&view_skey, rct::sk2rct(view_skey).bytes, rct::sk2rct(k).bytes); - return view_skey; - } - //----------------------------------------------------------------- - crypto::public_key generate_multisig_M_N_spend_public_key(const std::vector &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, size_t multisig_key_index, const crypto::public_key& out_key, crypto::key_image& ki) + //---------------------------------------------------------------------------------------------------------------------- + bool generate_multisig_key_image(const cryptonote::account_keys &keys, + std::size_t multisig_key_index, + const crypto::public_key& out_key, + crypto::key_image& ki) { if (multisig_key_index >= keys.m_multisig_keys.size()) return false; crypto::generate_key_image(out_key, 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) + //---------------------------------------------------------------------------------------------------------------------- + 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 std::unordered_map& subaddresses, const crypto::public_key& out_key, const crypto::public_key &tx_public_key, const std::vector& additional_tx_public_keys, size_t real_output_index, const std::vector &pkis, crypto::key_image &ki) + //---------------------------------------------------------------------------------------------------------------------- + bool generate_multisig_composite_key_image(const cryptonote::account_keys &keys, + const std::unordered_map &subaddresses, + const crypto::public_key &out_key, + const crypto::public_key &tx_public_key, + const std::vector &additional_tx_public_keys, + std::size_t real_output_index, + const std::vector &pkis, + crypto::key_image &ki) { + // create a multisig partial key image + // KI_partial = ([view key component] + [subaddress component] + [multisig privkeys]) * Hp(output one-time address) + // - the 'multisig priv keys' here are those held by the local account + // - later, we add in the components held by other participants cryptonote::keypair in_ephemeral; if (!cryptonote::generate_key_image_helper(keys, subaddresses, out_key, tx_public_key, additional_tx_public_keys, real_output_index, in_ephemeral, ki, keys.get_device())) return false; std::unordered_set used; - for (size_t m = 0; m < keys.m_multisig_keys.size(); ++m) + + // create a key image component for each of the local account's multisig private keys + for (std::size_t m = 0; m < keys.m_multisig_keys.size(); ++m) { crypto::key_image pki; - bool r = cryptonote::generate_multisig_key_image(keys, m, out_key, pki); + // pki = keys.m_multisig_keys[m] * Hp(out_key) + // pki = key image component + // out_key = one-time address of an output owned by the multisig group + bool r = generate_multisig_key_image(keys, m, out_key, pki); if (!r) return false; + + // this KI component is 'used' because it was included in the partial key image 'ki' above used.insert(pki); } + + // add the KI components from other participants to the partial KI + // if they not included yet for (const auto &pki: pkis) { if (used.find(pki) == used.end()) { + // ignore components that have already been 'used' used.insert(pki); + + // KI_partial = KI_partial + KI_component[...] rct::addKeys((rct::key&)ki, rct::ki2rct(ki), rct::ki2rct(pki)); } } + + // at the end, 'ki' will hold the true key image for our output if inputs were sufficient + // - if 'pkis' (the other participants' KI components) is missing some components + // then 'ki' will not be complete + return true; } - //----------------------------------------------------------------- - uint32_t multisig_rounds_required(uint32_t participants, uint32_t threshold) - { - CHECK_AND_ASSERT_THROW_MES(participants >= threshold, "participants must be greater or equal than threshold"); - return participants - threshold + 1; - } -} + //---------------------------------------------------------------------------------------------------------------------- +} //namespace multisig diff --git a/src/multisig/multisig.h b/src/multisig/multisig.h index eab32187c..e041ea670 100644 --- a/src/multisig/multisig.h +++ b/src/multisig/multisig.h @@ -1,4 +1,4 @@ -// Copyright (c) 2017-2020, The Monero Project +// Copyright (c) 2017-2021, The Monero Project // // All rights reserved. // @@ -28,44 +28,42 @@ #pragma once -#include -#include #include "crypto/crypto.h" #include "cryptonote_basic/cryptonote_format_utils.h" #include "ringct/rctTypes.h" -namespace cryptonote -{ - struct account_keys; +#include +#include +#include +namespace cryptonote { struct account_keys; } + +namespace multisig +{ + /** + * @brief get_multisig_blinded_secret_key - converts an input private key into a blinded multisig private key + * Use 1a: converts account private spend key into multisig private key, which is used for key exchange and message signing + * Use 1b: converts account private view key into ancillary private key share, for the composite multisig private view key + * Use 2: converts DH shared secrets (curve points) into private keys, which are intermediate private keys in multisig key exchange + * @param key - private key to transform + * @return transformed private key + */ crypto::secret_key get_multisig_blinded_secret_key(const crypto::secret_key &key); - void generate_multisig_N_N(const account_keys &keys, const std::vector &spend_keys, std::vector &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey); - void generate_multisig_N1_N(const account_keys &keys, const std::vector &spend_keys, std::vector &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey); - /** - * @brief generate_multisig_derivations performs common DH key derivation. - * Each middle round in M/N scheme is DH exchange of public multisig keys of other participants multiplied by secret spend key of current participant. - * this functions does the following: new multisig key = secret spend * public multisig key - * @param keys - current wallet's keys - * @param derivations - public multisig keys of other participants - * @return new public multisig keys derived from previous round. This data needs to be exchange with other participants - */ - std::vector generate_multisig_derivations(const account_keys &keys, const std::vector &derivations); - crypto::secret_key calculate_multisig_signer_key(const std::vector& derivations); - /** - * @brief calculate_multisig_keys. Calculates secret multisig keys from others' participants ones as follows: mi = H(Mi) - * @param derivations - others' participants public multisig keys. - * @return vector of current wallet's multisig secret keys - */ - std::vector calculate_multisig_keys(const std::vector& derivations); - crypto::secret_key generate_multisig_view_secret_key(const crypto::secret_key &skey, const std::vector &skeys); - /** - * @brief generate_multisig_M_N_spend_public_key calculates multisig wallet's spend public key by summing all of public multisig keys - * @param pkeys unique public multisig keys - * @return multisig wallet's spend public key - */ - crypto::public_key generate_multisig_M_N_spend_public_key(const std::vector &pkeys); - bool generate_multisig_key_image(const account_keys &keys, size_t multisig_key_index, const crypto::public_key& out_key, crypto::key_image& ki); - 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 std::unordered_map& subaddresses, const crypto::public_key& out_key, const crypto::public_key &tx_public_key, const std::vector& additional_tx_public_keys, size_t real_output_index, const std::vector &pkis, crypto::key_image &ki); - uint32_t multisig_rounds_required(uint32_t participants, uint32_t threshold); -} + + bool generate_multisig_key_image(const cryptonote::account_keys &keys, + std::size_t multisig_key_index, + const crypto::public_key& out_key, + crypto::key_image& ki); + 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 cryptonote::account_keys &keys, + const std::unordered_map &subaddresses, + const crypto::public_key &out_key, + const crypto::public_key &tx_public_key, + const std::vector &additional_tx_public_keys, + std::size_t real_output_index, + const std::vector &pkis, + crypto::key_image &ki); +} //namespace multisig 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 +#include +#include + + +#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{}, 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 signers, + const crypto::secret_key &base_privkey, + const crypto::secret_key &base_common_privkey, + std::vector 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 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 signers, + const std::vector &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 &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 diff --git a/src/multisig/multisig_account.h b/src/multisig/multisig_account.h new file mode 100644 index 000000000..b01ae6c88 --- /dev/null +++ b/src/multisig/multisig_account.h @@ -0,0 +1,246 @@ +// 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. + +#pragma once + +#include "crypto/crypto.h" +#include "multisig_kex_msg.h" + +#include +#include +#include +#include +#include + + +namespace multisig +{ + /** + * multisig account: + * + * - handles account keys for an M-of-N multisig participant (M <= N; M >= 1; N >= 2) + * - encapsulates multisig account construction process (via key exchange [kex]) + * - TODO: encapsulates key preparation for aggregation-style signing + * + * :: multisig pubkey: the private key is split, M group participants are required to reassemble (e.g. to sign something) + * - in cryptonote, this is the multisig spend key + * :: multisig common pubkey: the private key is known to all participants (e.g. for authenticating as a group member) + * - in cryptonote, this is the multisig view key + * + * + * multisig key exchange: + * + * An 'M-of-N' (M <= N; M >= 1; N >= 2) multisignature key is a public key where at least 'M' out of 'N' + * possible co-signers must collaborate in order to create a signature. + * + * Constructing a multisig key involves a series of Diffie-Hellman exchanges between participants. + * At the end of key exchange (kex), each participant will hold a number of private keys. Each private + * key is shared by a group of (N - M + 1) participants. This way if (N - M) co-signers are missing, every + * private key will be held by at least one of the remaining M people. + * + * Note on MULTISIG_MAX_SIGNERS: During key exchange, participants will have up to '(N - 1) choose (N - M)' + * key shares. If N is large, then the max number of key shares (when M = (N-1)/2) can be huge. A limit of N <= 16 was + * arbitrarily chosen as a power of 2 that can accomodate the vast majority of practical use-cases. To increase the + * limit, FROST-style key aggregation should be used instead (it is more efficient than DH-based key generation + * when N - M > 1). + * + * - Further reading + * - MRL-0009: https://www.getmonero.org/resources/research-lab/pubs/MRL-0009.pdf + * - MuSig2: https://eprint.iacr.org/2020/1261 + * - ZtM2: https://web.getmonero.org/library/Zero-to-Monero-2-0-0.pdf Ch. 9, especially Section 9.6.3 + * - FROST: https://eprint.iacr.org/2018/417 + */ + class multisig_account final + { + public: + //member types + using kex_origins_map_t = std::unordered_map>; + + //constructors + // default constructor + multisig_account() = default; + + /** + * construct from base privkeys + * + * - prepares a kex msg for the first round of multisig key construction. + * - the local account's kex msgs are signed with the base_privkey + * - the first kex msg transmits the local base_common_privkey to other participants, for creating the group's common_privkey + */ + multisig_account(const crypto::secret_key &base_privkey, + const crypto::secret_key &base_common_privkey); + + // reconstruct from full account details (not recommended) + multisig_account(const std::uint32_t threshold, + std::vector signers, + const crypto::secret_key &base_privkey, + const crypto::secret_key &base_common_privkey, + std::vector 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); + + // copy constructor: default + + //destructor: default + ~multisig_account() = default; + + //overloaded operators: none + + //getters + // get threshold + std::uint32_t get_threshold() const { return m_threshold; } + // get signers + const std::vector& get_signers() const { return m_signers; } + // get base privkey + const crypto::secret_key& get_base_privkey() const { return m_base_privkey; } + // get base pubkey + const crypto::public_key& get_base_pubkey() const { return m_base_pubkey; } + // get base common privkey + const crypto::secret_key& get_base_common_privkey() const { return m_base_common_privkey; } + // get multisig privkeys + const std::vector& get_multisig_privkeys() const { return m_multisig_privkeys; } + // get common privkey + const crypto::secret_key& get_common_privkey() const { return m_common_privkey; } + // get multisig pubkey + const crypto::public_key& get_multisig_pubkey() const { return m_multisig_pubkey; } + // get common pubkey + const crypto::public_key& get_common_pubkey() const { return m_common_pubkey; } + // get kex rounds complete + std::uint32_t get_kex_rounds_complete() const { return m_kex_rounds_complete; } + // get kex keys to origins map + const kex_origins_map_t& get_kex_keys_to_origins_map() const { return m_kex_keys_to_origins_map; } + // get the kex msg for the next round + const std::string& get_next_kex_round_msg() const { return m_next_round_kex_message; } + + //account status functions + // account has been intialized, and the account holder can use the 'common' key + bool account_is_active() const; + // account is ready to make multisig signatures + bool multisig_is_ready() const; + + //account helpers + private: + // set the threshold (M) and signers (N) + void set_multisig_config(const std::size_t threshold, std::vector signers); + + //account mutators: key exchange to set up account + public: + /** + * brief: initialize_kex - initialize key exchange + * - Updates the account with a 'transactional' model. This account will only be mutated if the update succeeds. + */ + void initialize_kex(const std::uint32_t threshold, + std::vector signers, + const std::vector &expanded_msgs_rnd1); + /** + * brief: kex_update - Complete the 'in progress' kex round and set the kex message for the next round. + * - Updates the account with a 'transactional' model. This account will only be mutated if the update succeeds. + * - The main interface for multisig key exchange, this handles all the work of processing input messages, + * creating new messages for new rounds, and finalizing the multisig shared public key when kex is complete. + * param: expanded_msgs - kex messages corresponding to the account's 'in progress' round + */ + void kex_update(const std::vector &expanded_msgs); + + private: + // implementation of kex_update() (non-transactional) + void kex_update_impl(const std::vector &expanded_msgs); + /** + * brief: initialize_kex_update - Helper for kex_update_impl() + * - Collect the local signer's shared keys to ignore in incoming messages, build the aggregate ancillary key + * if appropriate. + * param: expanded_msgs - set of multisig kex messages to process + * param: rounds_required - number of rounds required for kex + * outparam: exclude_pubkeys_out - keys held by the local account corresponding to round 'current_round' + * - If 'current_round' is the final round, these are the local account's shares of the final aggregate key. + */ + void initialize_kex_update(const std::vector &expanded_msgs, + const std::uint32_t rounds_required, + std::vector &exclude_pubkeys_out); + /** + * brief: finalize_kex_update - Helper for kex_update_impl() + * param: rounds_required - number of rounds required for kex + * param: result_keys_to_origins_map - map between keys for the next round and the other participants they correspond to + * inoutparam: temp_account_inout - account to perform last update steps on + */ + void finalize_kex_update(const std::uint32_t rounds_required, + kex_origins_map_t result_keys_to_origins_map); + + //member variables + private: + /// misc. account details + // [M] minimum number of co-signers to sign a message with the aggregate pubkey + std::uint32_t m_threshold{0}; + // [N] base keys of all participants in the multisig (used to initiate key exchange, and as participant ids for msg signing) + std::vector m_signers; + + /// local participant's personal keys + // base keypair of the participant + // - used for signing messages, as the initial base key for key exchange, and to make DH derivations for key exchange + crypto::secret_key m_base_privkey; + crypto::public_key m_base_pubkey; + // common base privkey, used to produce the aggregate common privkey + crypto::secret_key m_base_common_privkey; + + /// core multisig account keys + // the account's private key shares of the multisig address + // TODO: also record which other signers have these privkeys, to enable aggregation signing (instead of round-robin) + std::vector m_multisig_privkeys; + // a privkey owned by all multisig participants (e.g. a cryptonote view key) + crypto::secret_key m_common_privkey; + // the multisig public key (e.g. a cryptonote spend key) + crypto::public_key m_multisig_pubkey; + // the common public key (e.g. a view spend key) + crypto::public_key m_common_pubkey; + + /// kex variables + // number of key exchange rounds that have been completed (all messages for the round collected and processed) + std::uint32_t m_kex_rounds_complete{0}; + // this account's pubkeys for the in-progress key exchange round + // - either DH derivations (intermediate rounds), H(derivation)*G (final round), empty (when kex is done) + kex_origins_map_t m_kex_keys_to_origins_map; + // the account's message for the in-progress key exchange round + std::string m_next_round_kex_message; + }; + + /** + * brief: multisig_kex_rounds_required - The number of key exchange rounds required to produce an M-of-N shared key. + * - Key exchange (kex) is a synchronous series of 'rounds'. In an 'active round', participants send messages + * to each other. + * - A participant considers a round 'complete' when they have collected sufficient messages + * from other participants, processed those messages, and updated their multisig account state. + * - Typically (as implemented in this module), completing a round coincides with making a message for the next round. + * param: num_signers - number of participants in multisig (N) + * param: threshold - threshold of multisig (M) + * return: number of kex rounds required + */ + std::uint32_t multisig_kex_rounds_required(const std::uint32_t num_signers, const std::uint32_t threshold); +} //namespace multisig diff --git a/src/multisig/multisig_account_kex_impl.cpp b/src/multisig/multisig_account_kex_impl.cpp new file mode 100644 index 000000000..0a0ca7bdc --- /dev/null +++ b/src/multisig/multisig_account_kex_impl.cpp @@ -0,0 +1,726 @@ +// 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 + +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +#undef MONERO_DEFAULT_LOG_CATEGORY +#define MONERO_DEFAULT_LOG_CATEGORY "multisig" + +namespace multisig +{ + //---------------------------------------------------------------------------------------------------------------------- + /** + * INTERNAL + * + * brief: calculate_multisig_keypair_from_derivation - wrapper on calculate_multisig_keypair() for an input public key + * Converts an input public key into a crypto private key (type cast, does not change serialization), + * then passes it to get_multisig_blinded_secret_key(). + * + * Result: + * - privkey = H(derivation) + * - pubkey = privkey * G + * param: derivation - a curve point + * outparam: derived_pubkey_out - public key of the resulting privkey + * return: multisig private key + */ + //---------------------------------------------------------------------------------------------------------------------- + static crypto::secret_key calculate_multisig_keypair_from_derivation(const crypto::public_key_memsafe &derivation, + crypto::public_key &derived_pubkey_out) + { + crypto::secret_key blinded_skey = get_multisig_blinded_secret_key(rct::rct2sk(rct::pk2rct(derivation))); + CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(blinded_skey, derived_pubkey_out), "Failed to derive public key"); + + return blinded_skey; + } + //---------------------------------------------------------------------------------------------------------------------- + /** + * INTERNAL + * + * brief: make_multisig_common_privkey - Create the 'common' multisig privkey, owned by all multisig participants. + * - common privkey = H(sorted base common privkeys) + * param: participant_base_common_privkeys - Base common privkeys contributed by multisig participants. + * outparam: common_privkey_out - result + */ + //---------------------------------------------------------------------------------------------------------------------- + static void make_multisig_common_privkey(std::vector participant_base_common_privkeys, + crypto::secret_key &common_privkey_out) + { + // sort the privkeys for consistency + //TODO: need a constant-time operator< for sorting secret keys + std::sort(participant_base_common_privkeys.begin(), participant_base_common_privkeys.end(), + [](const crypto::secret_key &key1, const crypto::secret_key &key2) -> bool + { + return memcmp(&key1, &key2, sizeof(crypto::secret_key)) < 0; + } + ); + + // privkey = H(sorted ancillary base privkeys) + crypto::hash_to_scalar(participant_base_common_privkeys.data(), + participant_base_common_privkeys.size()*sizeof(crypto::secret_key), + common_privkey_out); + + CHECK_AND_ASSERT_THROW_MES(common_privkey_out != crypto::null_skey, "Unexpected null secret key (danger!)."); + } + //---------------------------------------------------------------------------------------------------------------------- + /** + * INTERNAL + * + * brief: compute_multisig_aggregation_coefficient - creates aggregation coefficient for a specific public key in a set + * of public keys + * + * WARNING: The coefficient will only be deterministic if... + * 1) input keys are pre-sorted + * - tested here + * 2) input keys are in canonical form (compressed points in the prime-order subgroup of Ed25519) + * - untested here for performance + * param: sorted_keys - set of component public keys that will be merged into a multisig public spend key + * param: aggregation_key - one of the component public keys + * return: aggregation coefficient + */ + //---------------------------------------------------------------------------------------------------------------------- + static rct::key compute_multisig_aggregation_coefficient(const std::vector &sorted_keys, + const crypto::public_key &aggregation_key) + { + CHECK_AND_ASSERT_THROW_MES(std::is_sorted(sorted_keys.begin(), sorted_keys.end()), + "Keys for aggregation coefficient aren't sorted."); + + // aggregation key must be in sorted_keys + CHECK_AND_ASSERT_THROW_MES(std::find(sorted_keys.begin(), sorted_keys.end(), aggregation_key) != sorted_keys.end(), + "Aggregation key expected to be in input keyset."); + + // aggregation coefficient salt + rct::key salt = rct::zero(); + static_assert(sizeof(rct::key) >= sizeof(config::HASH_KEY_MULTISIG_KEY_AGGREGATION), "Hash domain separator is too big."); + memcpy(salt.bytes, config::HASH_KEY_MULTISIG_KEY_AGGREGATION, sizeof(config::HASH_KEY_MULTISIG_KEY_AGGREGATION)); + + // coeff = H(aggregation_key, sorted_keys, domain-sep) + rct::keyV data; + data.reserve(sorted_keys.size() + 2); + data.push_back(rct::pk2rct(aggregation_key)); + for (const auto &key : sorted_keys) + data.push_back(rct::pk2rct(key)); + data.push_back(salt); + + // note: coefficient is considered public knowledge, no need to memwipe data + return rct::hash_to_scalar(data); + } + //---------------------------------------------------------------------------------------------------------------------- + /** + * INTERNAL + * + * brief: generate_multisig_aggregate_key - generates a multisig public spend key via key aggregation + * Key aggregation via aggregation coefficients prevents key cancellation attacks. + * See: https://www.getmonero.org/resources/research-lab/pubs/MRL-0009.pdf + * param: final_keys - address components (public keys) obtained from other participants (not shared with local) + * param: privkeys_inout - private keys of address components known by local; each key will be multiplied by an aggregation coefficient (return by reference) + * return: final multisig public spend key for the account + */ + //---------------------------------------------------------------------------------------------------------------------- + static crypto::public_key generate_multisig_aggregate_key(std::vector final_keys, + std::vector &privkeys_inout) + { + // collect all public keys that will go into the spend key (these don't need to be memsafe) + final_keys.reserve(final_keys.size() + privkeys_inout.size()); + + // 1. convert local multisig private keys to pub keys + // 2. insert to final keyset if not there yet + // 3. save the corresponding index of input priv key set for later reference + std::unordered_map own_keys_mapping; + + for (std::size_t multisig_keys_index{0}; multisig_keys_index < privkeys_inout.size(); ++multisig_keys_index) + { + crypto::public_key pubkey; + CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(privkeys_inout[multisig_keys_index], pubkey), "Failed to derive public key"); + + own_keys_mapping[pubkey] = multisig_keys_index; + + final_keys.push_back(pubkey); + } + + // sort input final keys for computing aggregation coefficients (lowest to highest) + // note: input should be sanitized (no duplicates) + std::sort(final_keys.begin(), final_keys.end()); + CHECK_AND_ASSERT_THROW_MES(std::adjacent_find(final_keys.begin(), final_keys.end()) == final_keys.end(), + "Unexpected duplicate found in input list."); + + // key aggregation + rct::key aggregate_key = rct::identity(); + + for (const crypto::public_key &key : final_keys) + { + // get aggregation coefficient + rct::key coeff = compute_multisig_aggregation_coefficient(final_keys, key); + + // convert private key if possible + // note: retain original priv key index in input list, in case order matters upstream + auto found_key = own_keys_mapping.find(key); + if (found_key != own_keys_mapping.end()) + { + // k_agg = coeff*k_base + sc_mul((unsigned char*)&(privkeys_inout[found_key->second]), + coeff.bytes, + (const unsigned char*)&(privkeys_inout[found_key->second])); + + CHECK_AND_ASSERT_THROW_MES(privkeys_inout[found_key->second] != crypto::null_skey, + "Multisig privkey with aggregation coefficient unexpectedly null."); + } + + // convert public key (pre-merge operation) + // K_agg = coeff*K_base + rct::key converted_pubkey = rct::scalarmultKey(rct::pk2rct(key), coeff); + + // build aggregate key (merge operation) + rct::addKeys(aggregate_key, aggregate_key, converted_pubkey); + } + + return rct::rct2pk(aggregate_key); + } + //---------------------------------------------------------------------------------------------------------------------- + /** + * INTERNAL + * + * brief: multisig_kex_make_next_msg - Construct a kex msg for any round > 1 of multisig key construction. + * - Involves DH exchanges with pubkeys provided by other participants. + * - Conserves mapping [pubkey -> DH derivation] : [origin keys of participants that share this secret with you]. + * param: base_privkey - account's base private key, for performing DH exchanges and signing messages + * param: round - the round of the message that should be produced + * param: threshold - threshold for multisig (M in M-of-N) + * param: num_signers - number of participants in multisig (N) + * param: pubkey_origins_map - map between pubkeys to produce DH derivations with and identity keys of + * participants who will share each derivation with you + * outparam: derivation_origins_map_out - map between DH derivations (shared secrets) and identity keys + * - If msg is not for the last round, then these derivations are also stored in the output message + * so they can be sent to other participants, who will make more DH derivations for the next kex round. + * - If msg is for the last round, then these derivations won't be sent to other participants. + * Instead, they are converted to share secrets (i.e. s = H(derivation)) and multiplied by G. + * The keys s*G are sent to other participants in the message, so they can be used to produce the final + * multisig key via generate_multisig_spend_public_key(). + * - The values s are the local account's shares of the final multisig key's private key. The caller can + * compute those values with calculate_multisig_keypair_from_derivation() (or compute them directly). + * return: multisig kex message for the specified round + */ + //---------------------------------------------------------------------------------------------------------------------- + static multisig_kex_msg multisig_kex_make_next_msg(const crypto::secret_key &base_privkey, + const std::uint32_t round, + const std::uint32_t threshold, + const std::uint32_t num_signers, + const std::unordered_map> &pubkey_origins_map, + std::unordered_map> &derivation_origins_map_out) + { + CHECK_AND_ASSERT_THROW_MES(num_signers > 1, "Must be at least one other multisig signer."); + CHECK_AND_ASSERT_THROW_MES(num_signers <= config::MULTISIG_MAX_SIGNERS, + "Too many multisig signers specified (limit = 16 to prevent dangerous combinatorial explosion during key exchange)."); + CHECK_AND_ASSERT_THROW_MES(num_signers >= threshold, + "Multisig threshold may not be larger than number of signers."); + CHECK_AND_ASSERT_THROW_MES(threshold > 0, "Multisig threshold must be > 0."); + CHECK_AND_ASSERT_THROW_MES(round > 1, "Round for next msg must be > 1."); + CHECK_AND_ASSERT_THROW_MES(round <= multisig_kex_rounds_required(num_signers, threshold), + "Trying to make key exchange message for an invalid round."); + + // make shared secrets with input pubkeys + std::vector msg_pubkeys; + msg_pubkeys.reserve(pubkey_origins_map.size()); + derivation_origins_map_out.clear(); + + for (const auto &pubkey_and_origins : pubkey_origins_map) + { + // D = 8 * k_base * K_pubkey + // note: must be mul8 (cofactor), otherwise it is possible to leak to a malicious participant if the local + // base_privkey is a multiple of 8 or not + // note2: avoid making temporaries that won't be memwiped + rct::key derivation_rct; + auto a_wiper = epee::misc_utils::create_scope_leave_handler([&]{ + memwipe(&derivation_rct, sizeof(rct::key)); + }); + + rct::scalarmultKey(derivation_rct, rct::pk2rct(pubkey_and_origins.first), rct::sk2rct(base_privkey)); + rct::scalarmultKey(derivation_rct, derivation_rct, rct::EIGHT); + + crypto::public_key_memsafe derivation{rct::rct2pk(derivation_rct)}; + + // retain mapping between pubkey's origins and the DH derivation + // note: if msg for last round, then caller must know how to handle these derivations properly + derivation_origins_map_out[derivation] = pubkey_and_origins.second; + + // if the last round, convert derivations to public keys for the output message + if (round == multisig_kex_rounds_required(num_signers, threshold)) + { + // derived_pubkey = H(derivation)*G + crypto::public_key derived_pubkey; + calculate_multisig_keypair_from_derivation(derivation, derived_pubkey); + msg_pubkeys.push_back(derived_pubkey); + } + // otherwise, put derivations in message directly, so other signers can in turn create derivations (shared secrets) + // with them for the next round + else + msg_pubkeys.push_back(derivation); + } + + return multisig_kex_msg{round, base_privkey, std::move(msg_pubkeys)}; + } + //---------------------------------------------------------------------------------------------------------------------- + /** + * INTERNAL + * + * brief: multisig_kex_msgs_sanitize_pubkeys - Sanitize multisig kex messages. + * - Removes duplicates from msg pubkeys, ignores pubkeys equal to the local account's signing key, + * ignores messages signed by the local account, ignores keys found in input 'exclusion set', + * constructs map of pubkey:origins. + * - Requires that all input msgs have the same round number. + * + * origins = all the signing pubkeys that recommended a given pubkey found in input msgs + * + * - If the messages' round numbers are all '1', then only the message signing pubkey is considered + * 'recommended'. Furthermore, the 'exclusion set' is ignored. + * param: own_pubkey - local account's signing key (key used to sign multisig messages) + * param: expanded_msgs - set of multisig kex messages to process + * param: exclude_pubkeys - pubkeys to exclude from output set + * outparam: sanitized_pubkeys_out - processed pubkeys obtained from msgs, mapped to their origins + * return: round number shared by all input msgs + */ + //---------------------------------------------------------------------------------------------------------------------- + static std::uint32_t multisig_kex_msgs_sanitize_pubkeys(const crypto::public_key &own_pubkey, + const std::vector &expanded_msgs, + const std::vector &exclude_pubkeys, + std::unordered_map> &sanitized_pubkeys_out) + { + CHECK_AND_ASSERT_THROW_MES(expanded_msgs.size() > 0, "At least one input message expected."); + + std::uint32_t round = expanded_msgs[0].get_round(); + sanitized_pubkeys_out.clear(); + + // get all pubkeys from input messages, add them to pubkey:origins map + // - origins = all the signing pubkeys that recommended a given msg pubkey + for (const auto &expanded_msg : expanded_msgs) + { + CHECK_AND_ASSERT_THROW_MES(expanded_msg.get_round() == round, "All messages must have the same kex round number."); + + // ignore messages from self + if (expanded_msg.get_signing_pubkey() == own_pubkey) + continue; + + // in round 1, only the signing pubkey is treated as a msg pubkey + if (round == 1) + { + // note: ignores duplicates + sanitized_pubkeys_out[expanded_msg.get_signing_pubkey()].insert(expanded_msg.get_signing_pubkey()); + } + // in other rounds, only the msg pubkeys are treated as msg pubkeys + else + { + // copy all pubkeys from message into list + for (const auto &pubkey : expanded_msg.get_msg_pubkeys()) + { + // ignore own pubkey + if (pubkey == own_pubkey) + continue; + + // ignore pubkeys in 'ignore' set + if (std::find(exclude_pubkeys.begin(), exclude_pubkeys.end(), pubkey) != exclude_pubkeys.end()) + continue; + + // note: ignores duplicates + sanitized_pubkeys_out[pubkey].insert(expanded_msg.get_signing_pubkey()); + } + } + } + + return round; + } + //---------------------------------------------------------------------------------------------------------------------- + /** + * INTERNAL + * + * brief: evaluate_multisig_kex_round_msgs - Evaluate pubkeys from a kex round in order to prepare for the next round. + * - Sanitizes input msgs. + * - Require uniqueness in: 'signers', 'exclude_pubkeys'. + * - Requires each input pubkey be recommended by 'num_recommendations = expected_round' msg signers. + * - For a final multisig key to be truly 'M-of-N', each of the the private key's components must be + * shared by (N - M + 1) signers. + * - Requires that msgs are signed by only keys in 'signers'. + * - Requires that each key in 'signers' recommends [num_signers - 2 CHOOSE (expected_round - 1)] pubkeys. + * - These should be derivations each signer recommends for round 'expected_round', excluding derivations shared + * with the local account. + * - Requires that 'exclude_pubkeys' has [num_signers - 1 CHOOSE (expected_round - 1)] pubkeys. + * - These should be derivations the local account has corresponding to round 'expected_round'. + * param: base_privkey - multisig account's base private key + * param: expected_round - expected kex round of input messages + * param: threshold - threshold for multisig (M in M-of-N) + * param: signers - expected participants in multisig kex + * param: expanded_msgs - set of multisig kex messages to process + * param: exclude_pubkeys - derivations held by the local account corresponding to round 'expected_round' + * return: fully sanitized and validated pubkey:origins map for building the account's next kex round message + */ + //---------------------------------------------------------------------------------------------------------------------- + static std::unordered_map> evaluate_multisig_kex_round_msgs( + const crypto::public_key &base_pubkey, + const std::uint32_t expected_round, + const std::uint32_t threshold, + const std::vector &signers, + const std::vector &expanded_msgs, + const std::vector &exclude_pubkeys) + { + CHECK_AND_ASSERT_THROW_MES(signers.size() > 1, "Must be at least one other multisig signer."); + CHECK_AND_ASSERT_THROW_MES(signers.size() <= config::MULTISIG_MAX_SIGNERS, + "Too many multisig signers specified (limit = 16 to prevent dangerous combinatorial explosion during key exchange)."); + CHECK_AND_ASSERT_THROW_MES(signers.size() >= threshold, "Multisig threshold may not be larger than number of signers."); + CHECK_AND_ASSERT_THROW_MES(threshold > 0, "Multisig threshold must be > 0."); + CHECK_AND_ASSERT_THROW_MES(expected_round > 0, "Expected round must be > 0."); + CHECK_AND_ASSERT_THROW_MES(expected_round <= multisig_kex_rounds_required(signers.size(), threshold), + "Expecting key exchange messages for an invalid round."); + + std::unordered_map> pubkey_origins_map; + + // leave early in the last round of 1-of-N, where all signers share a key so the local signer doesn't care about + // recommendations from other signers + if (threshold == 1 && expected_round == multisig_kex_rounds_required(signers.size(), threshold)) + return pubkey_origins_map; + + // exclude_pubkeys should all be unique + for (auto it = exclude_pubkeys.begin(); it != exclude_pubkeys.end(); ++it) + { + CHECK_AND_ASSERT_THROW_MES(std::find(exclude_pubkeys.begin(), it, *it) == it, + "Found duplicate pubkeys for exclusion unexpectedly."); + } + + // sanitize input messages + std::uint32_t round = multisig_kex_msgs_sanitize_pubkeys(base_pubkey, expanded_msgs, exclude_pubkeys, pubkey_origins_map); + CHECK_AND_ASSERT_THROW_MES(round == expected_round, + "Kex messages were for round [" << round << "], but expected round is [" << expected_round << "]"); + + // evaluate pubkeys collected + std::unordered_map> origin_pubkeys_map; + + // 1. each pubkey should be recommended by a precise number of signers + for (const auto &pubkey_and_origins : pubkey_origins_map) + { + // expected amount = round_num + // With each successive round, pubkeys are shared by incrementally larger groups, + // starting at 1 in round 1 (i.e. the local multisig key to start kex with). + CHECK_AND_ASSERT_THROW_MES(pubkey_and_origins.second.size() == round, + "A pubkey recommended by multisig kex messages had an unexpected number of recommendations."); + + // map (sanitized) pubkeys back to origins + for (const auto &origin : pubkey_and_origins.second) + origin_pubkeys_map[origin].insert(pubkey_and_origins.first); + } + + // 2. the number of unique signers recommending pubkeys should equal the number of signers passed in (minus the local signer) + CHECK_AND_ASSERT_THROW_MES(origin_pubkeys_map.size() == signers.size() - 1, + "Number of unique other signers does not equal number of other signers that recommended pubkeys."); + + // 3. each origin should recommend a precise number of pubkeys + + // TODO: move to a 'math' library, with unit tests + auto n_choose_k_f = + [](const std::uint32_t n, const std::uint32_t k) -> std::uint32_t + { + static_assert(std::numeric_limits::digits <= std::numeric_limits::digits, + "n_choose_k requires no rounding issues when converting between int32 <-> double."); + + if (n < k) + return 0; + + double fp_result = boost::math::binomial_coefficient(n, k); + + if (fp_result < 0) + return 0; + + if (fp_result > std::numeric_limits::max()) // note: std::round() returns std::int32_t + return 0; + + return static_cast(std::round(fp_result)); + }; + + // other signers: (N - 2) choose (msg_round_num - 1) + // - Each signer recommends keys they share with other signers. + // - In each round, a signer shares a key with 'round num - 1' other signers. + // - Since 'origins pubkey map' excludes keys shared with the local account, + // only keys shared with participants 'other than local and self' will be in the map (e.g. N - 2 signers). + // - So other signers will recommend (N - 2) choose (msg_round_num - 1) pubkeys (after removing keys shared with local). + // - Each origin should have a shared key with each group of size 'round - 1'. + // Note: Keys shared with local are ignored to facilitate kex round boosting, where one or more signers may + // have boosted the local signer (implying they didn't have access to the local signer's previous round msg). + std::uint32_t expected_recommendations_others = n_choose_k_f(signers.size() - 2, round - 1); + + // local: (N - 1) choose (msg_round_num - 1) + std::uint32_t expected_recommendations_self = n_choose_k_f(signers.size() - 1, round - 1); + + // note: expected_recommendations_others would be 0 in the last round of 1-of-N, but we return early for that case + CHECK_AND_ASSERT_THROW_MES(expected_recommendations_self > 0 && expected_recommendations_others > 0, + "Bad num signers or round num (possibly numerical limits exceeded)."); + + // check that local account recommends expected number of keys + CHECK_AND_ASSERT_THROW_MES(exclude_pubkeys.size() == expected_recommendations_self, + "Local account did not recommend expected number of multisig keys."); + + // check that other signers recommend expected number of keys + for (const auto &origin_and_pubkeys : origin_pubkeys_map) + { + CHECK_AND_ASSERT_THROW_MES(origin_and_pubkeys.second.size() == expected_recommendations_others, + "A pubkey recommended by multisig kex messages had an unexpected number of recommendations."); + + // 2 (continued). only expected signers should be recommending keys + CHECK_AND_ASSERT_THROW_MES(std::find(signers.begin(), signers.end(), origin_and_pubkeys.first) != signers.end(), + "Multisig kex message with unexpected signer encountered."); + } + + // note: above tests implicitly detect if the total number of recommended keys is correct or not + return pubkey_origins_map; + } + //---------------------------------------------------------------------------------------------------------------------- + /** + * INTERNAL + * + * brief: multisig_kex_process_round - Process kex messages for the active kex round. + * - A wrapper around evaluate_multisig_kex_round_msgs() -> multisig_kex_make_next_msg(). + * - In other words, evaluate the input messages and try to make a message for the next round. + * - Note: Must be called on the final round's msgs to evaluate the final key components + * recommended by other participants. + * param: base_privkey - multisig account's base private key + * param: current_round - round of kex the input messages should be designed for + * param: threshold - threshold for multisig (M in M-of-N) + * param: signers - expected participants in multisig kex + * param: expanded_msgs - set of multisig kex messages to process + * param: exclude_pubkeys - keys held by the local account corresponding to round 'current_round' + * - If 'current_round' is the final round, these are the local account's shares of the final aggregate key. + * outparam: keys_to_origins_map_out - map between round keys and identity keys + * - If in the final round, these are key shares recommended by other signers for the final aggregate key. + * - Otherwise, these are the local account's DH derivations for the next round. + * - See multisig_kex_make_next_msg() for an explanation. + * return: multisig kex message for next round, or empty message if 'current_round' is the final round + */ + //---------------------------------------------------------------------------------------------------------------------- + static multisig_kex_msg multisig_kex_process_round(const crypto::secret_key &base_privkey, + const crypto::public_key &base_pubkey, + const std::uint32_t current_round, + const std::uint32_t threshold, + const std::vector &signers, + const std::vector &expanded_msgs, + const std::vector &exclude_pubkeys, + std::unordered_map> &keys_to_origins_map_out) + { + // evaluate messages + std::unordered_map> evaluated_pubkeys = + evaluate_multisig_kex_round_msgs(base_pubkey, current_round, threshold, signers, expanded_msgs, exclude_pubkeys); + + // produce message for next round (if there is one) + if (current_round < multisig_kex_rounds_required(signers.size(), threshold)) + { + return multisig_kex_make_next_msg(base_privkey, + current_round + 1, + threshold, + signers.size(), + evaluated_pubkeys, + keys_to_origins_map_out); + } + else + { + // no more rounds, so collect the key shares recommended by other signers for the final aggregate key + keys_to_origins_map_out.clear(); + keys_to_origins_map_out = std::move(evaluated_pubkeys); + + return multisig_kex_msg{}; + } + } + //---------------------------------------------------------------------------------------------------------------------- + // multisig_account: INTERNAL + //---------------------------------------------------------------------------------------------------------------------- + void multisig_account::initialize_kex_update(const std::vector &expanded_msgs, + const std::uint32_t rounds_required, + std::vector &exclude_pubkeys_out) + { + if (m_kex_rounds_complete == 0) + { + // the first round of kex msgs will contain each participant's base pubkeys and ancillary privkeys + + // collect participants' base common privkey shares + // note: duplicate privkeys are acceptable, and duplicates due to duplicate signers + // will be blocked by duplicate-signer errors after this function is called + std::vector participant_base_common_privkeys; + participant_base_common_privkeys.reserve(expanded_msgs.size() + 1); + + // add local ancillary base privkey + participant_base_common_privkeys.emplace_back(m_base_common_privkey); + + // add other signers' base common privkeys + for (const auto &expanded_msg : expanded_msgs) + { + if (expanded_msg.get_signing_pubkey() != m_base_pubkey) + { + participant_base_common_privkeys.emplace_back(expanded_msg.get_msg_privkey()); + } + } + + // make common privkey + make_multisig_common_privkey(std::move(participant_base_common_privkeys), m_common_privkey); + + // set common pubkey + CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(m_common_privkey, m_common_pubkey), + "Failed to derive public key"); + + // if N-of-N, then the base privkey will be used directly to make the account's share of the final key + if (rounds_required == 1) + { + m_multisig_privkeys.clear(); + m_multisig_privkeys.emplace_back(m_base_privkey); + } + + // exclude all keys the local account recommends + // - in the first round, only the local pubkey is recommended by the local signer + exclude_pubkeys_out.emplace_back(m_base_pubkey); + } + else + { + // in other rounds, kex msgs will contain participants' shared keys + + // ignore shared keys the account helped create for this round + for (const auto &shared_key_with_origins : m_kex_keys_to_origins_map) + { + exclude_pubkeys_out.emplace_back(shared_key_with_origins.first); + } + } + } + //---------------------------------------------------------------------------------------------------------------------- + // multisig_account: INTERNAL + //---------------------------------------------------------------------------------------------------------------------- + void multisig_account::finalize_kex_update(const std::uint32_t rounds_required, + std::unordered_map> result_keys_to_origins_map) + { + // prepare for next round (or complete the multisig account fully) + if (rounds_required == m_kex_rounds_complete + 1) + { + // finished (have set of msgs to complete address) + + // when 'completing the final round', result keys are other signers' shares of the final key + std::vector result_keys; + result_keys.reserve(result_keys_to_origins_map.size()); + + for (const auto &result_key_and_origins : result_keys_to_origins_map) + { + result_keys.emplace_back(result_key_and_origins.first); + } + + // compute final aggregate key, update local multisig privkeys with aggregation coefficients applied + m_multisig_pubkey = generate_multisig_aggregate_key(std::move(result_keys), m_multisig_privkeys); + + // no longer need the account's pubkeys saved for this round (they were only used to build exclude_pubkeys) + // TODO: record [pre-aggregation pubkeys : origins] map for aggregation-style signing + m_kex_keys_to_origins_map.clear(); + } + else if (rounds_required == m_kex_rounds_complete + 2) + { + // one more round (must send/receive one more set of kex msgs) + // - at this point, have local signer's pre-aggregation private key shares of the final address + + // result keys are the local signer's DH derivations for the next round + + // derivations are shared secrets between each group of N - M + 1 signers of which the local account is a member + // - convert them to private keys: multisig_key = H(derivation) + // - note: shared key = multisig_key[i]*G is recorded in the kex msg for sending to other participants + // instead of the original 'derivation' value (which MUST be kept secret!) + m_multisig_privkeys.clear(); + m_multisig_privkeys.reserve(result_keys_to_origins_map.size()); + + m_kex_keys_to_origins_map.clear(); + + for (const auto &derivation_and_origins : result_keys_to_origins_map) + { + // multisig_privkey = H(derivation) + // derived pubkey = multisig_key * G + crypto::public_key_memsafe derived_pubkey; + m_multisig_privkeys.push_back( + calculate_multisig_keypair_from_derivation(derivation_and_origins.first, derived_pubkey)); + + // save the account's kex key mappings for this round [derived pubkey : other signers who will have the same key] + m_kex_keys_to_origins_map[derived_pubkey] = std::move(derivation_and_origins.second); + } + } + else + { + // next round is an 'intermediate' key exchange round, so there is nothing special to do here + + // save the account's kex keys for this round [DH derivation : other signers who will have the same derivation] + m_kex_keys_to_origins_map = std::move(result_keys_to_origins_map); + } + + // a full set of msgs has been collected and processed, so the 'round is complete' + ++m_kex_rounds_complete; + } + //---------------------------------------------------------------------------------------------------------------------- + // multisig_account: INTERNAL + //---------------------------------------------------------------------------------------------------------------------- + void multisig_account::kex_update_impl(const std::vector &expanded_msgs) + { + CHECK_AND_ASSERT_THROW_MES(expanded_msgs.size() > 0, "No key exchange messages passed in."); + + const std::uint32_t rounds_required = multisig_kex_rounds_required(m_signers.size(), m_threshold); + CHECK_AND_ASSERT_THROW_MES(rounds_required > 0, "Multisig kex rounds required unexpectedly 0."); + + // initialize account update + std::vector exclude_pubkeys; + initialize_kex_update(expanded_msgs, rounds_required, exclude_pubkeys); + + // evaluate messages and get this account's kex msg for the next round + std::unordered_map> result_keys_to_origins_map; + + m_next_round_kex_message = multisig_kex_process_round( + m_base_privkey, + m_base_pubkey, + m_kex_rounds_complete + 1, + m_threshold, + m_signers, + expanded_msgs, + exclude_pubkeys, + result_keys_to_origins_map).get_msg(); + + // finish account update + finalize_kex_update(rounds_required, std::move(result_keys_to_origins_map)); + } + //---------------------------------------------------------------------------------------------------------------------- +} //namespace multisig diff --git a/src/multisig/multisig_kex_msg.cpp b/src/multisig/multisig_kex_msg.cpp new file mode 100644 index 000000000..89dcbfffd --- /dev/null +++ b/src/multisig/multisig_kex_msg.cpp @@ -0,0 +1,292 @@ +// 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_kex_msg.h" +#include "multisig_kex_msg_serialization.h" + +#include "common/base58.h" +#include "crypto/crypto.h" +extern "C" +{ +#include "crypto/crypto-ops.h" +} +#include "cryptonote_basic/cryptonote_format_utils.h" +#include "include_base_utils.h" +#include "ringct/rctOps.h" +#include "serialization/binary_archive.h" +#include "serialization/serialization.h" + +#include + +#include +#include +#include + + +#undef MONERO_DEFAULT_LOG_CATEGORY +#define MONERO_DEFAULT_LOG_CATEGORY "multisig" + +const boost::string_ref MULTISIG_KEX_V1_MAGIC{"MultisigV1"}; +const boost::string_ref MULTISIG_KEX_MSG_V1_MAGIC{"MultisigxV1"}; +const boost::string_ref MULTISIG_KEX_MSG_V2_MAGIC_1{"MultisigxV2R1"}; //round 1 +const boost::string_ref MULTISIG_KEX_MSG_V2_MAGIC_N{"MultisigxV2Rn"}; //round n > 1 + +namespace multisig +{ + //---------------------------------------------------------------------------------------------------------------------- + // multisig_kex_msg: EXTERNAL + //---------------------------------------------------------------------------------------------------------------------- + multisig_kex_msg::multisig_kex_msg(const std::uint32_t round, + const crypto::secret_key &signing_privkey, + std::vector msg_pubkeys, + const crypto::secret_key &msg_privkey) : + m_kex_round{round} + { + CHECK_AND_ASSERT_THROW_MES(round > 0, "Kex round must be > 0."); + CHECK_AND_ASSERT_THROW_MES(sc_check((const unsigned char*)&signing_privkey) == 0 && + signing_privkey != crypto::null_skey, "Invalid msg signing key."); + + if (round == 1) + { + CHECK_AND_ASSERT_THROW_MES(sc_check((const unsigned char*)&msg_privkey) == 0 && + msg_privkey != crypto::null_skey, "Invalid msg privkey."); + + m_msg_privkey = msg_privkey; + } + else + { + for (const auto &pubkey : msg_pubkeys) + { + CHECK_AND_ASSERT_THROW_MES(pubkey != crypto::null_pkey && pubkey != rct::rct2pk(rct::identity()), + "Pubkey for message was invalid."); + CHECK_AND_ASSERT_THROW_MES((rct::scalarmultKey(rct::pk2rct(pubkey), rct::curveOrder()) == rct::identity()), + "Pubkey for message was not in prime subgroup."); + } + + m_msg_pubkeys = std::move(msg_pubkeys); + } + CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(signing_privkey, m_signing_pubkey), + "Failed to derive public key"); + + // sets message and signing pub key + construct_msg(signing_privkey); + } + //---------------------------------------------------------------------------------------------------------------------- + // multisig_kex_msg: EXTERNAL + //---------------------------------------------------------------------------------------------------------------------- + multisig_kex_msg::multisig_kex_msg(std::string msg) : m_msg{std::move(msg)} + { + parse_and_validate_msg(); + } + //---------------------------------------------------------------------------------------------------------------------- + // multisig_kex_msg: INTERNAL + //---------------------------------------------------------------------------------------------------------------------- + crypto::hash multisig_kex_msg::get_msg_to_sign() const + { + //// + // msg_content = kex_round | signing_pubkey | expand(msg_pubkeys) | OPTIONAL msg_privkey + // sign_msg = versioning-domain-sep | msg_content + /// + + std::string data; + CHECK_AND_ASSERT_THROW_MES(MULTISIG_KEX_MSG_V2_MAGIC_1.size() == MULTISIG_KEX_MSG_V2_MAGIC_N.size(), + "Multisig kex msg magic inconsistency."); + data.reserve(MULTISIG_KEX_MSG_V2_MAGIC_1.size() + 4 + 32*(1 + (m_kex_round == 1 ? 1 : 0) + m_msg_pubkeys.size())); + + // versioning domain-sep + if (m_kex_round == 1) + data.append(MULTISIG_KEX_MSG_V2_MAGIC_1.data(), MULTISIG_KEX_MSG_V2_MAGIC_1.size()); + else + data.append(MULTISIG_KEX_MSG_V2_MAGIC_N.data(), MULTISIG_KEX_MSG_V2_MAGIC_N.size()); + + // kex_round as little-endian bytes + for (std::size_t i{0}; i < 4; ++i) + { + data += static_cast(m_kex_round >> i*8); + } + + // signing pubkey + data.append((const char *)&m_signing_pubkey, sizeof(crypto::public_key)); + + // add msg privkey if kex_round == 1 + if (m_kex_round == 1) + data.append((const char *)&m_msg_privkey, sizeof(crypto::secret_key)); + else + { + // only add pubkeys if not round 1 + + // msg pubkeys + for (const auto &key : m_msg_pubkeys) + data.append((const char *)&key, sizeof(crypto::public_key)); + } + + // message to sign + crypto::hash hash; + crypto::cn_fast_hash(data.data(), data.size(), hash); + + return hash; + } + //---------------------------------------------------------------------------------------------------------------------- + // multisig_kex_msg: INTERNAL + //---------------------------------------------------------------------------------------------------------------------- + void multisig_kex_msg::construct_msg(const crypto::secret_key &signing_privkey) + { + //// + // msg_content = kex_round | signing_pubkey | expand(msg_pubkeys) | OPTIONAL msg_privkey + // sign_msg = versioning-domain-sep | msg_content + // msg = versioning-domain-sep | serialize(msg_content | crypto_sig[signing_privkey](sign_msg)) + /// + + // sign the message + crypto::signature msg_signature; + crypto::hash msg_to_sign{get_msg_to_sign()}; + crypto::generate_signature(msg_to_sign, m_signing_pubkey, signing_privkey, msg_signature); + + // assemble the message + m_msg.clear(); + + std::stringstream serialized_msg_ss; + binary_archive b_archive(serialized_msg_ss); + + if (m_kex_round == 1) + { + m_msg.append(MULTISIG_KEX_MSG_V2_MAGIC_1.data(), MULTISIG_KEX_MSG_V2_MAGIC_1.size()); + + multisig_kex_msg_serializable_round1 msg_serializable; + msg_serializable.msg_privkey = m_msg_privkey; + msg_serializable.signing_pubkey = m_signing_pubkey; + msg_serializable.signature = msg_signature; + + CHECK_AND_ASSERT_THROW_MES(::serialization::serialize(b_archive, msg_serializable), + "Failed to serialize multisig kex msg"); + } + else + { + m_msg.append(MULTISIG_KEX_MSG_V2_MAGIC_N.data(), MULTISIG_KEX_MSG_V2_MAGIC_N.size()); + + multisig_kex_msg_serializable_general msg_serializable; + msg_serializable.kex_round = m_kex_round; + msg_serializable.msg_pubkeys = m_msg_pubkeys; + msg_serializable.signing_pubkey = m_signing_pubkey; + msg_serializable.signature = msg_signature; + + CHECK_AND_ASSERT_THROW_MES(::serialization::serialize(b_archive, msg_serializable), + "Failed to serialize multisig kex msg"); + } + + m_msg.append(tools::base58::encode(serialized_msg_ss.str())); + } + //---------------------------------------------------------------------------------------------------------------------- + // multisig_kex_msg: INTERNAL + //---------------------------------------------------------------------------------------------------------------------- + void multisig_kex_msg::parse_and_validate_msg() + { + // check message type + CHECK_AND_ASSERT_THROW_MES(m_msg.size() > 0, "Kex message unexpectedly empty."); + CHECK_AND_ASSERT_THROW_MES(m_msg.substr(0, MULTISIG_KEX_V1_MAGIC.size()) != MULTISIG_KEX_V1_MAGIC, + "V1 multisig kex messages are deprecated (unsafe)."); + CHECK_AND_ASSERT_THROW_MES(m_msg.substr(0, MULTISIG_KEX_MSG_V1_MAGIC.size()) != MULTISIG_KEX_MSG_V1_MAGIC, + "V1 multisig kex messages are deprecated (unsafe)."); + + // deserialize the message + std::string msg_no_magic; + CHECK_AND_ASSERT_THROW_MES(MULTISIG_KEX_MSG_V2_MAGIC_1.size() == MULTISIG_KEX_MSG_V2_MAGIC_N.size(), + "Multisig kex msg magic inconsistency."); + CHECK_AND_ASSERT_THROW_MES(tools::base58::decode(m_msg.substr(MULTISIG_KEX_MSG_V2_MAGIC_1.size()), msg_no_magic), + "Multisig kex msg decoding error."); + std::stringstream temp_msg_no_magic; + temp_msg_no_magic << msg_no_magic; + binary_archive b_archive{temp_msg_no_magic}; + crypto::signature msg_signature; + + if (m_msg.substr(0, MULTISIG_KEX_MSG_V2_MAGIC_1.size()) == MULTISIG_KEX_MSG_V2_MAGIC_1) + { + // try round 1 message + multisig_kex_msg_serializable_round1 kex_msg_rnd1; + + if (::serialization::serialize(b_archive, kex_msg_rnd1)) + { + // in round 1 the message stores a private ancillary key component for the multisig account + // that will be shared by all participants (e.g. a shared private view key) + m_kex_round = 1; + m_msg_privkey = kex_msg_rnd1.msg_privkey; + m_signing_pubkey = kex_msg_rnd1.signing_pubkey; + msg_signature = kex_msg_rnd1.signature; + } + else + { + CHECK_AND_ASSERT_THROW_MES(false, "Deserializing kex msg failed."); + } + } + else if (m_msg.substr(0, MULTISIG_KEX_MSG_V2_MAGIC_N.size()) == MULTISIG_KEX_MSG_V2_MAGIC_N) + { + // try general message + multisig_kex_msg_serializable_general kex_msg_general; + + if (::serialization::serialize(b_archive, kex_msg_general)) + { + m_kex_round = kex_msg_general.kex_round; + m_msg_privkey = crypto::null_skey; + m_msg_pubkeys = std::move(kex_msg_general.msg_pubkeys); + m_signing_pubkey = kex_msg_general.signing_pubkey; + msg_signature = kex_msg_general.signature; + + CHECK_AND_ASSERT_THROW_MES(m_kex_round > 1, "Invalid kex message round (must be > 1 for the general msg type)."); + } + else + { + CHECK_AND_ASSERT_THROW_MES(false, "Deserializing kex msg failed."); + } + } + else + { + // unknown message type + CHECK_AND_ASSERT_THROW_MES(false, "Only v2 multisig kex messages are supported."); + } + + // checks + for (const auto &pubkey: m_msg_pubkeys) + { + CHECK_AND_ASSERT_THROW_MES(pubkey != crypto::null_pkey && pubkey != rct::rct2pk(rct::identity()), + "Pubkey from message was invalid."); + CHECK_AND_ASSERT_THROW_MES(rct::isInMainSubgroup(rct::pk2rct(pubkey)), + "Pubkey from message was not in prime subgroup."); + } + + CHECK_AND_ASSERT_THROW_MES(m_signing_pubkey != crypto::null_pkey && m_signing_pubkey != rct::rct2pk(rct::identity()), + "Message signing key was invalid."); + CHECK_AND_ASSERT_THROW_MES(rct::isInMainSubgroup(rct::pk2rct(m_signing_pubkey)), + "Message signing key was not in prime subgroup."); + + // validate signature + crypto::hash signed_msg{get_msg_to_sign()}; + CHECK_AND_ASSERT_THROW_MES(crypto::check_signature(signed_msg, m_signing_pubkey, msg_signature), + "Multisig kex msg signature invalid."); + } + //---------------------------------------------------------------------------------------------------------------------- +} //namespace multisig diff --git a/src/multisig/multisig_kex_msg.h b/src/multisig/multisig_kex_msg.h new file mode 100644 index 000000000..23e3042f2 --- /dev/null +++ b/src/multisig/multisig_kex_msg.h @@ -0,0 +1,109 @@ +// 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. + +#pragma once + +#include "crypto/crypto.h" + +#include +#include + + +namespace multisig +{ + //// + // multisig key exchange message + // - can parse and validate an input message + // - can construct and sign a new message + // + // msg_content = kex_round | signing_pubkey | expand(msg_pubkeys) | OPTIONAL msg_privkey + // msg_to_sign = versioning-domain-sep | msg_content + // msg = versioning-domain-sep | b58(msg_content | crypto_sig[signing_privkey](msg_to_sign)) + // + // note: round 1 messages will contain a private key (e.g. for the aggregate multisig private view key) + /// + class multisig_kex_msg final + { + //member types: none + + //constructors + public: + // default constructor + multisig_kex_msg() = default; + + // construct from info + multisig_kex_msg(const std::uint32_t round, + const crypto::secret_key &signing_privkey, + std::vector msg_pubkeys, + const crypto::secret_key &msg_privkey = crypto::null_skey); + + // construct from string + multisig_kex_msg(std::string msg); + + // copy constructor: default + + //destructor: default + ~multisig_kex_msg() = default; + + //overloaded operators: none + + //member functions + // get msg string + const std::string& get_msg() const { return m_msg; } + // get kex round + std::uint32_t get_round() const { return m_kex_round; } + // get msg pubkeys + const std::vector& get_msg_pubkeys() const { return m_msg_pubkeys; } + // get msg privkey + const crypto::secret_key& get_msg_privkey() const { return m_msg_privkey; } + // get msg signing pubkey + const crypto::public_key& get_signing_pubkey() const { return m_signing_pubkey; } + + private: + // msg_to_sign = versioning-domain-sep | kex_round | signing_pubkey | expand(msg_pubkeys) | OPTIONAL msg_privkey + crypto::hash get_msg_to_sign() const; + // set: msg string based on msg contents, signing pubkey based on input privkey + void construct_msg(const crypto::secret_key &signing_privkey); + // parse msg string into parts, validate contents and signature + void parse_and_validate_msg(); + + //member variables + private: + // message as string + std::string m_msg; + + // key exchange round this msg was produced for + std::uint32_t m_kex_round; + // pubkeys stored in msg + std::vector m_msg_pubkeys; + // privkey stored in msg (if kex round 1) + crypto::secret_key m_msg_privkey; + // pubkey used to sign this msg + crypto::public_key m_signing_pubkey; + }; +} //namespace multisig diff --git a/src/multisig/multisig_kex_msg_serialization.h b/src/multisig/multisig_kex_msg_serialization.h new file mode 100644 index 000000000..9c7b993a7 --- /dev/null +++ b/src/multisig/multisig_kex_msg_serialization.h @@ -0,0 +1,78 @@ +// 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. + +#pragma once + +#include "crypto/crypto.h" +#include "serialization/containers.h" +#include "serialization/crypto.h" +#include "serialization/serialization.h" + +#include +#include + + +namespace multisig +{ + /// round 1 kex message + struct multisig_kex_msg_serializable_round1 + { + // privkey stored in msg + crypto::secret_key msg_privkey; + // pubkey used to sign this msg + crypto::public_key signing_pubkey; + // message signature + crypto::signature signature; + + BEGIN_SERIALIZE() + FIELD(msg_privkey) + FIELD(signing_pubkey) + FIELD(signature) + END_SERIALIZE() + }; + + /// general kex message (if round > 1) + struct multisig_kex_msg_serializable_general + { + // key exchange round this msg was produced for + std::uint32_t kex_round; + // pubkeys stored in msg + std::vector msg_pubkeys; + // pubkey used to sign this msg + crypto::public_key signing_pubkey; + // message signature + crypto::signature signature; + + BEGIN_SERIALIZE() + VARINT_FIELD(kex_round) + FIELD(msg_pubkeys) + FIELD(signing_pubkey) + FIELD(signature) + END_SERIALIZE() + }; +} //namespace multisig diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp index a18152e68..2258daa62 100644 --- a/src/simplewallet/simplewallet.cpp +++ b/src/simplewallet/simplewallet.cpp @@ -233,7 +233,6 @@ namespace const char* USAGE_IMPORT_OUTPUTS("import_outputs "); const char* USAGE_SHOW_TRANSFER("show_transfer "); const char* USAGE_MAKE_MULTISIG("make_multisig [...]"); - const char* USAGE_FINALIZE_MULTISIG("finalize_multisig [...]"); const char* USAGE_EXCHANGE_MULTISIG_KEYS("exchange_multisig_keys [...]"); const char* USAGE_EXPORT_MULTISIG_INFO("export_multisig_info "); const char* USAGE_IMPORT_MULTISIG_INFO("import_multisig_info [...]"); @@ -1013,7 +1012,7 @@ bool simple_wallet::prepare_multisig_main(const std::vector &args, SCOPED_WALLET_UNLOCK_ON_BAD_PASSWORD(return false;); - std::string multisig_info = m_wallet->get_multisig_info(); + std::string multisig_info = m_wallet->get_multisig_first_kex_msg(); success_msg_writer() << multisig_info; success_msg_writer() << tr("Send this multisig info to all other participants, then use make_multisig [...] with others' multisig info"); success_msg_writer() << tr("This includes the PRIVATE view key, so needs to be disclosed only to that multisig wallet's participants "); @@ -1114,58 +1113,6 @@ bool simple_wallet::make_multisig_main(const std::vector &args, boo return true; } -bool simple_wallet::finalize_multisig(const std::vector &args) -{ - bool ready; - if (m_wallet->key_on_device()) - { - fail_msg_writer() << tr("command not supported by HW wallet"); - return true; - } - - const auto pwd_container = get_and_verify_password(); - if(pwd_container == boost::none) - { - fail_msg_writer() << tr("Your original password was incorrect."); - return true; - } - - if (!m_wallet->multisig(&ready)) - { - fail_msg_writer() << tr("This wallet is not multisig"); - return true; - } - if (ready) - { - fail_msg_writer() << tr("This wallet is already finalized"); - return true; - } - - LOCK_IDLE_SCOPE(); - - if (args.size() < 2) - { - PRINT_USAGE(USAGE_FINALIZE_MULTISIG); - return true; - } - - try - { - if (!m_wallet->finalize_multisig(pwd_container->password(), args)) - { - fail_msg_writer() << tr("Failed to finalize multisig"); - return true; - } - } - catch (const std::exception &e) - { - fail_msg_writer() << tr("Failed to finalize multisig: ") << e.what(); - return true; - } - - return true; -} - bool simple_wallet::exchange_multisig_keys(const std::vector &args) { exchange_multisig_keys_main(args, false); @@ -3543,10 +3490,6 @@ simple_wallet::simple_wallet() m_cmd_binder.set_handler("make_multisig", boost::bind(&simple_wallet::on_command, this, &simple_wallet::make_multisig, _1), tr(USAGE_MAKE_MULTISIG), tr("Turn this wallet into a multisig wallet")); - m_cmd_binder.set_handler("finalize_multisig", - boost::bind(&simple_wallet::on_command, this, &simple_wallet::finalize_multisig, _1), - tr(USAGE_FINALIZE_MULTISIG), - tr("Turn this wallet into a multisig wallet, extra step for N-1/N wallets")); m_cmd_binder.set_handler("exchange_multisig_keys", boost::bind(&simple_wallet::on_command, this, &simple_wallet::exchange_multisig_keys, _1), tr(USAGE_EXCHANGE_MULTISIG_KEYS), @@ -10843,8 +10786,8 @@ void simple_wallet::mms_init(const std::vector &args) std::vector numbers; boost::split(numbers, mn, boost::is_any_of("/")); bool mn_ok = (numbers.size() == 2) - && get_number_from_arg(numbers[1], num_authorized_signers, 2, 100) - && get_number_from_arg(numbers[0], num_required_signers, 2, num_authorized_signers); + && get_number_from_arg(numbers[1], num_authorized_signers, 2, config::MULTISIG_MAX_SIGNERS) + && get_number_from_arg(numbers[0], num_required_signers, 1, num_authorized_signers); if (!mn_ok) { fail_msg_writer() << tr("Error in the number of required signers and/or authorized signers"); diff --git a/src/simplewallet/simplewallet.h b/src/simplewallet/simplewallet.h index 5846fe056..760784e95 100644 --- a/src/simplewallet/simplewallet.h +++ b/src/simplewallet/simplewallet.h @@ -231,7 +231,6 @@ namespace cryptonote bool prepare_multisig_main(const std::vector& args, bool called_by_mms); bool make_multisig(const std::vector& args); bool make_multisig_main(const std::vector& args, bool called_by_mms); - bool finalize_multisig(const std::vector &args); bool exchange_multisig_keys(const std::vector &args); bool exchange_multisig_keys_main(const std::vector &args, bool called_by_mms); bool export_multisig(const std::vector& args); diff --git a/src/wallet/api/wallet.cpp b/src/wallet/api/wallet.cpp index 92ab55a50..02966012c 100644 --- a/src/wallet/api/wallet.cpp +++ b/src/wallet/api/wallet.cpp @@ -1335,7 +1335,7 @@ MultisigState WalletImpl::multisig() const { string WalletImpl::getMultisigInfo() const { try { clearStatus(); - return m_wallet->get_multisig_info(); + return m_wallet->get_multisig_first_kex_msg(); } catch (const exception& e) { LOG_ERROR("Error on generating multisig info: " << e.what()); setStatusError(string(tr("Failed to get multisig info: ")) + e.what()); @@ -1344,7 +1344,7 @@ string WalletImpl::getMultisigInfo() const { return string(); } -string WalletImpl::makeMultisig(const vector& info, uint32_t threshold) { +string WalletImpl::makeMultisig(const vector& info, const uint32_t threshold) { try { clearStatus(); @@ -1369,30 +1369,12 @@ std::string WalletImpl::exchangeMultisigKeys(const std::vector &inf return m_wallet->exchange_multisig_keys(epee::wipeable_string(m_password), info); } catch (const exception& e) { LOG_ERROR("Error on exchanging multisig keys: " << e.what()); - setStatusError(string(tr("Failed to make multisig: ")) + e.what()); + setStatusError(string(tr("Failed to exchange multisig keys: ")) + e.what()); } return string(); } -bool WalletImpl::finalizeMultisig(const vector& extraMultisigInfo) { - try { - clearStatus(); - checkMultisigWalletNotReady(m_wallet); - - if (m_wallet->finalize_multisig(epee::wipeable_string(m_password), extraMultisigInfo)) { - return true; - } - - setStatusError(tr("Failed to finalize multisig wallet creation")); - } catch (const exception& e) { - LOG_ERROR("Error on finalizing multisig wallet creation: " << e.what()); - setStatusError(string(tr("Failed to finalize multisig wallet creation: ")) + e.what()); - } - - return false; -} - bool WalletImpl::exportMultisigImages(string& images) { try { clearStatus(); diff --git a/src/wallet/api/wallet.h b/src/wallet/api/wallet.h index 5b78e496e..6dfb67ccc 100644 --- a/src/wallet/api/wallet.h +++ b/src/wallet/api/wallet.h @@ -147,7 +147,6 @@ public: std::string getMultisigInfo() const override; std::string makeMultisig(const std::vector& info, uint32_t threshold) override; std::string exchangeMultisigKeys(const std::vector &info) override; - bool finalizeMultisig(const std::vector& extraMultisigInfo) override; bool exportMultisigImages(std::string& images) override; size_t importMultisigImages(const std::vector& images) override; bool hasMultisigPartialKeyImages() const override; diff --git a/src/wallet/api/wallet2_api.h b/src/wallet/api/wallet2_api.h index 0b8be83d9..4396fedf8 100644 --- a/src/wallet/api/wallet2_api.h +++ b/src/wallet/api/wallet2_api.h @@ -790,7 +790,7 @@ struct Wallet /** * @brief makeMultisig - switches wallet in multisig state. The one and only creation phase for N / N wallets * @param info - vector of multisig infos from other participants obtained with getMulitisInfo call - * @param threshold - number of required signers to make valid transaction. Must be equal to number of participants (N) or N - 1 + * @param threshold - number of required signers to make valid transaction. Must be <= number of participants * @return in case of N / N wallets returns empty string since no more key exchanges needed. For N - 1 / N wallets returns base58 encoded extra multisig info */ virtual std::string makeMultisig(const std::vector& info, uint32_t threshold) = 0; @@ -800,12 +800,6 @@ struct Wallet * @return new info string if more rounds required or an empty string if wallet creation is done */ virtual std::string exchangeMultisigKeys(const std::vector &info) = 0; - /** - * @brief finalizeMultisig - finalizes N - 1 / N multisig wallets creation - * @param extraMultisigInfo - wallet participants' extra multisig info obtained with makeMultisig call - * @return true if success - */ - virtual bool finalizeMultisig(const std::vector& extraMultisigInfo) = 0; /** * @brief exportMultisigImages - exports transfers' key images * @param images - output paramter for hex encoded array of images diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp index cbdda4f72..f9e207d69 100644 --- a/src/wallet/wallet2.cpp +++ b/src/wallet/wallet2.cpp @@ -28,6 +28,7 @@ // // Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers +#include #include #include #include @@ -56,6 +57,8 @@ using namespace epee; #include "misc_language.h" #include "cryptonote_basic/cryptonote_basic_impl.h" #include "multisig/multisig.h" +#include "multisig/multisig_account.h" +#include "multisig/multisig_kex_msg.h" #include "common/boost_serialization_helper.h" #include "common/command_line.h" #include "common/threadpool.h" @@ -146,7 +149,6 @@ using namespace cryptonote; #define RECENT_SPEND_WINDOW (15 * DIFFICULTY_TARGET_V2) static const std::string MULTISIG_SIGNATURE_MAGIC = "SigMultisigPkV1"; -static const std::string MULTISIG_EXTRA_INFO_MAGIC = "MultisigxV1"; static const std::string ASCII_OUTPUT_MAGIC = "MoneroAsciiDataV1"; @@ -164,42 +166,6 @@ namespace return dir.string(); } - std::string pack_multisignature_keys(const std::string& prefix, const std::vector& keys, const crypto::secret_key& signer_secret_key) - { - std::string data; - crypto::public_key signer; - CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(signer_secret_key, signer), "Failed to derive public spend key"); - data += std::string((const char *)&signer, sizeof(crypto::public_key)); - - for (const auto &key: keys) - { - data += std::string((const char *)&key, sizeof(crypto::public_key)); - } - - data.resize(data.size() + sizeof(crypto::signature)); - - crypto::hash hash; - crypto::cn_fast_hash(data.data(), data.size() - sizeof(crypto::signature), hash); - crypto::signature &signature = *(crypto::signature*)&data[data.size() - sizeof(crypto::signature)]; - crypto::generate_signature(hash, signer, signer_secret_key, signature); - - return MULTISIG_EXTRA_INFO_MAGIC + tools::base58::encode(data); - } - - std::vector secret_keys_to_public_keys(const std::vector& keys) - { - std::vector public_keys; - public_keys.reserve(keys.size()); - - std::transform(keys.begin(), keys.end(), std::back_inserter(public_keys), [] (const crypto::secret_key& k) -> crypto::public_key { - crypto::public_key p; - CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(k, p), "Failed to derive public spend key"); - return p; - }); - - return public_keys; - } - bool keys_intersect(const std::unordered_set& s1, const std::unordered_set& s2) { if (s1.empty() || s2.empty()) @@ -4681,7 +4647,6 @@ void wallet2::generate(const std::string& wallet_, const epee::wipeable_string& memwipe(&skey, sizeof(rct::key)); m_account.make_multisig(view_secret_key, spend_secret_key, spend_public_key, multisig_keys); - m_account.finalize_multisig(spend_public_key); // Not possible to restore a multisig wallet that is able to activate the MMS // (because the original keys are not (yet) part of the restore info), so @@ -4896,24 +4861,12 @@ void wallet2::restore(const std::string& wallet_, const epee::wipeable_string& p store(); } } - +//---------------------------------------------------------------------------------------------------- std::string wallet2::make_multisig(const epee::wipeable_string &password, - const std::vector &view_keys, - const std::vector &spend_keys, - uint32_t threshold) + const std::vector &initial_kex_msgs, + const std::uint32_t threshold) { - CHECK_AND_ASSERT_THROW_MES(!view_keys.empty(), "empty view keys"); - CHECK_AND_ASSERT_THROW_MES(view_keys.size() == spend_keys.size(), "Mismatched view/spend key sizes"); - CHECK_AND_ASSERT_THROW_MES(threshold > 1 && threshold <= spend_keys.size() + 1, "Invalid threshold"); - - std::string extra_multisig_info; - std::vector multisig_keys; - rct::key spend_pkey = rct::identity(); - rct::key spend_skey; - auto wiper = epee::misc_utils::create_scope_leave_handler([&](){memwipe(&spend_skey, sizeof(spend_skey));}); - std::vector multisig_signers; - - // decrypt keys + // decrypt account keys epee::misc_utils::auto_scope_leave_caller keys_reencryptor; if (m_ask_password == AskPasswordToDecrypt && !m_unattended && !m_watch_only) { @@ -4921,104 +4874,89 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password, crypto::generate_chacha_key(password.data(), password.size(), chacha_key, m_kdf_rounds); m_account.encrypt_viewkey(chacha_key); m_account.decrypt_keys(chacha_key); - keys_reencryptor = epee::misc_utils::create_scope_leave_handler([&, this, chacha_key]() { m_account.encrypt_keys(chacha_key); m_account.decrypt_viewkey(chacha_key); }); + keys_reencryptor = epee::misc_utils::create_scope_leave_handler( + [&, this, chacha_key]() + { + m_account.encrypt_keys(chacha_key); + m_account.decrypt_viewkey(chacha_key); + } + ); } - // In common multisig scheme there are 4 types of key exchange rounds: - // 1. First round is exchange of view secret keys and public spend keys. - // 2. Middle round is exchange of derivations: Ki = b * Mj, where b - spend secret key, - // M - public multisig key (in first round it equals to public spend key), K - new public multisig key. - // 3. Secret spend establishment round sets your secret multisig keys as follows: kl = H(Ml), where M - is *your* public multisig key, - // k - secret multisig key used to sign transactions. k and M are sets of keys, of course. - // And secret spend key as the sum of all participant's secret multisig keys - // 4. Last round establishes multisig wallet's public spend key. Participants exchange their public multisig keys - // and calculate common spend public key as sum of all unique participants' public multisig keys. - // Note that N/N scheme has only first round. N-1/N has 2 rounds: first and last. Common M/N has all 4 rounds. + // create multisig account + multisig::multisig_account multisig_account{ + multisig::get_multisig_blinded_secret_key(get_account().get_keys().m_spend_secret_key), + multisig::get_multisig_blinded_secret_key(get_account().get_keys().m_view_secret_key) + }; - // IMPORTANT: wallet's public spend key is not equal to secret_spend_key * G! - // Wallet's public spend key is the sum of unique public multisig keys of all participants. - // secret_spend_key * G = public signer key + // open initial kex messages, validate them, extract signers + std::vector expanded_msgs; + std::vector signers; + expanded_msgs.reserve(initial_kex_msgs.size()); + signers.reserve(initial_kex_msgs.size() + 1); - if (threshold == spend_keys.size() + 1) + for (const auto &msg : initial_kex_msgs) { - // In N / N case we only need to do one round and calculate secret multisig keys and new secret spend key - MINFO("Creating spend key..."); + expanded_msgs.emplace_back(msg); - // Calculates all multisig keys and spend key - cryptonote::generate_multisig_N_N(get_account().get_keys(), spend_keys, multisig_keys, spend_skey, spend_pkey); + // validate each message + // 1. must be 'round 1' + CHECK_AND_ASSERT_THROW_MES(expanded_msgs.back().get_round() == 1, + "Trying to make multisig with message that has invalid multisig kex round (should be '1')."); - // Our signer key is b * G, where b is secret spend key. - multisig_signers = spend_keys; - multisig_signers.push_back(get_multisig_signer_public_key(get_account().get_keys().m_spend_secret_key)); + // 2. duplicate signers not allowed + CHECK_AND_ASSERT_THROW_MES(std::find(signers.begin(), signers.end(), expanded_msgs.back().get_signing_pubkey()) == signers.end(), + "Duplicate signers not allowed when converting a wallet to multisig."); + + // add signer (skip self for now) + if (expanded_msgs.back().get_signing_pubkey() != multisig_account.get_base_pubkey()) + signers.push_back(expanded_msgs.back().get_signing_pubkey()); } - else - { - // We just got public spend keys of all participants and deriving multisig keys (set of Mi = b * Bi). - // note that derivations are public keys as DH exchange suppose it to be - auto derivations = cryptonote::generate_multisig_derivations(get_account().get_keys(), spend_keys); - spend_pkey = rct::identity(); - multisig_signers = std::vector(spend_keys.size() + 1, crypto::null_pkey); + // add self to signers + signers.push_back(multisig_account.get_base_pubkey()); - if (threshold == spend_keys.size()) - { - // N - 1 / N case + // intialize key exchange + multisig_account.initialize_kex(threshold, signers, expanded_msgs); + CHECK_AND_ASSERT_THROW_MES(multisig_account.account_is_active(), "Failed to activate multisig account."); - // We need an extra step, so we package all the composite public keys - // we know about, and make a signed string out of them - MINFO("Creating spend key..."); - - // Calculating set of our secret multisig keys as follows: mi = H(Mi), - // where mi - secret multisig key, Mi - others' participants public multisig key - multisig_keys = cryptonote::calculate_multisig_keys(derivations); - - // calculating current participant's spend secret key as sum of all secret multisig keys for current participant. - // IMPORTANT: participant's secret spend key is not an entire wallet's secret spend! - // Entire wallet's secret spend is sum of all unique secret multisig keys - // among all of participants and is not held by anyone! - spend_skey = rct::sk2rct(cryptonote::calculate_multisig_signer_key(multisig_keys)); - - // Preparing data for the last round to calculate common public spend key. The data contains public multisig keys. - extra_multisig_info = pack_multisignature_keys(MULTISIG_EXTRA_INFO_MAGIC, secret_keys_to_public_keys(multisig_keys), rct::rct2sk(spend_skey)); - } - else - { - // M / N case - MINFO("Preparing keys for next exchange round..."); - - // Preparing data for middle round - packing new public multisig keys to exchage with others. - extra_multisig_info = pack_multisignature_keys(MULTISIG_EXTRA_INFO_MAGIC, derivations, m_account.get_keys().m_spend_secret_key); - spend_skey = rct::sk2rct(m_account.get_keys().m_spend_secret_key); - - // Need to store middle keys to be able to proceed in case of wallet shutdown. - m_multisig_derivations = derivations; - } - } - + // update wallet state if (!m_original_keys_available) { // Save the original i.e. non-multisig keys so the MMS can continue to use them to encrypt and decrypt messages // (making a wallet multisig overwrites those keys, see account_base::make_multisig) - m_original_address = m_account.get_keys().m_account_address; - m_original_view_secret_key = m_account.get_keys().m_view_secret_key; + m_original_address = get_account().get_keys().m_account_address; + m_original_view_secret_key = get_account().get_keys().m_view_secret_key; m_original_keys_available = true; } clear(); - MINFO("Creating view key..."); - crypto::secret_key view_skey = cryptonote::generate_multisig_view_secret_key(get_account().get_keys().m_view_secret_key, view_keys); + // account base MINFO("Creating multisig address..."); - 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"); - memwipe(&spend_skey, sizeof(rct::key)); + CHECK_AND_ASSERT_THROW_MES(m_account.make_multisig(multisig_account.get_common_privkey(), + multisig_account.get_base_privkey(), + multisig_account.get_multisig_pubkey(), + multisig_account.get_multisig_privkeys()), + "Failed to create multisig wallet account due to bad keys"); init_type(hw::device::device_type::SOFTWARE); m_original_keys_available = true; m_multisig = true; m_multisig_threshold = threshold; - m_multisig_signers = multisig_signers; - ++m_multisig_rounds_passed; + m_multisig_signers = signers; + m_multisig_rounds_passed = 1; + + // derivations stored (should be empty in last round) + // TODO: make use of the origins map for aggregation-style signing (instead of round-robin) + m_multisig_derivations.clear(); + m_multisig_derivations.reserve(multisig_account.get_kex_keys_to_origins_map().size()); + + for (const auto &key_to_origins : multisig_account.get_kex_keys_to_origins_map()) + m_multisig_derivations.push_back(key_to_origins.first); + + // address + m_account_public_address.m_spend_public_key = multisig_account.get_multisig_pubkey(); // re-encrypt keys keys_reencryptor = epee::misc_utils::auto_scope_leave_caller(); @@ -5031,42 +4969,18 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password, if (!m_wallet_file.empty()) store(); - return extra_multisig_info; + return multisig_account.get_next_kex_round_msg(); } - +//---------------------------------------------------------------------------------------------------- std::string wallet2::exchange_multisig_keys(const epee::wipeable_string &password, - const std::vector &info) + const std::vector &kex_messages) { - THROW_WALLET_EXCEPTION_IF(info.empty(), - error::wallet_internal_error, "Empty multisig info"); - - if (info[0].substr(0, MULTISIG_EXTRA_INFO_MAGIC.size()) != MULTISIG_EXTRA_INFO_MAGIC) - { - THROW_WALLET_EXCEPTION_IF(false, - error::wallet_internal_error, "Unsupported info string"); - } - - std::vector signers; - std::unordered_set pkeys; - - THROW_WALLET_EXCEPTION_IF(!unpack_extra_multisig_info(info, signers, pkeys), - error::wallet_internal_error, "Bad extra multisig info"); - - return exchange_multisig_keys(password, pkeys, signers); -} - -std::string wallet2::exchange_multisig_keys(const epee::wipeable_string &password, - std::unordered_set derivations, - std::vector signers) -{ - CHECK_AND_ASSERT_THROW_MES(!derivations.empty(), "empty pkeys"); - CHECK_AND_ASSERT_THROW_MES(!signers.empty(), "empty signers"); - - bool ready = false; + bool ready{false}; CHECK_AND_ASSERT_THROW_MES(multisig(&ready), "The wallet is not multisig"); CHECK_AND_ASSERT_THROW_MES(!ready, "Multisig wallet creation process has already been finished"); + CHECK_AND_ASSERT_THROW_MES(kex_messages.size() > 0, "No key exchange messages passed in."); - // keys are decrypted + // decrypt account keys epee::misc_utils::auto_scope_leave_caller keys_reencryptor; if (m_ask_password == AskPasswordToDecrypt && !m_unattended && !m_watch_only) { @@ -5074,37 +4988,72 @@ std::string wallet2::exchange_multisig_keys(const epee::wipeable_string &passwor crypto::generate_chacha_key(password.data(), password.size(), chacha_key, m_kdf_rounds); m_account.encrypt_viewkey(chacha_key); m_account.decrypt_keys(chacha_key); - keys_reencryptor = epee::misc_utils::create_scope_leave_handler([&, this, chacha_key]() { m_account.encrypt_keys(chacha_key); m_account.decrypt_viewkey(chacha_key); }); + keys_reencryptor = epee::misc_utils::create_scope_leave_handler( + [&, this, chacha_key]() + { + m_account.encrypt_keys(chacha_key); + m_account.decrypt_viewkey(chacha_key); + } + ); } - if (m_multisig_rounds_passed == multisig_rounds_required(m_multisig_signers.size(), m_multisig_threshold) - 1) + // open kex messages + std::vector expanded_msgs; + expanded_msgs.reserve(kex_messages.size()); + + for (const auto &msg : kex_messages) + expanded_msgs.emplace_back(msg); + + // reconstruct multisig account + crypto::public_key dummy; + multisig::multisig_account::kex_origins_map_t kex_origins_map; + + for (const auto &derivation : m_multisig_derivations) + kex_origins_map[derivation]; + + multisig::multisig_account multisig_account{ + m_multisig_threshold, + m_multisig_signers, + get_account().get_keys().m_spend_secret_key, + crypto::null_skey, //base common privkey: not used + get_account().get_keys().m_multisig_keys, + get_account().get_keys().m_view_secret_key, + m_account_public_address.m_spend_public_key, + dummy, //common pubkey: not used + m_multisig_rounds_passed, + std::move(kex_origins_map), + "" + }; + + // update multisig kex + multisig_account.kex_update(expanded_msgs); + + // update wallet state + + // address + m_account_public_address.m_spend_public_key = multisig_account.get_multisig_pubkey(); + + // account base + CHECK_AND_ASSERT_THROW_MES(m_account.make_multisig(multisig_account.get_common_privkey(), + multisig_account.get_base_privkey(), + multisig_account.get_multisig_pubkey(), + multisig_account.get_multisig_privkeys()), + "Failed to update multisig wallet account due to bad keys"); + + // derivations stored (should be empty in last round) + // TODO: make use of the origins map for aggregation-style signing (instead of round-robin) + m_multisig_derivations.clear(); + m_multisig_derivations.reserve(multisig_account.get_kex_keys_to_origins_map().size()); + + for (const auto &key_to_origins : multisig_account.get_kex_keys_to_origins_map()) + m_multisig_derivations.push_back(key_to_origins.first); + + // rounds passed + m_multisig_rounds_passed = multisig_account.get_kex_rounds_complete(); + + // why is this necessary? who knows... + if (multisig_account.multisig_is_ready()) { - // the last round is passed and we have to calculate spend public key - // add ours if not included - crypto::public_key local_signer = get_multisig_signer_public_key(); - - if (std::find(signers.begin(), signers.end(), local_signer) == signers.end()) - { - signers.push_back(local_signer); - for (const auto &msk: get_account().get_multisig_keys()) - { - derivations.insert(rct::rct2pk(rct::scalarmultBase(rct::sk2rct(msk)))); - } - } - - CHECK_AND_ASSERT_THROW_MES(signers.size() == m_multisig_signers.size(), "Bad signers size"); - - // Summing all of unique public multisig keys to calculate common public spend key - crypto::public_key spend_public_key = cryptonote::generate_multisig_M_N_spend_public_key(std::vector(derivations.begin(), derivations.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)) < 0; }); - - ++m_multisig_rounds_passed; - m_multisig_derivations.clear(); - // keys are encrypted again keys_reencryptor = epee::misc_utils::auto_scope_leave_caller(); @@ -5126,270 +5075,28 @@ std::string wallet2::exchange_multisig_keys(const epee::wipeable_string &passwor if (!m_wallet_file.empty()) store(); - - return {}; } - // Below are either middle or secret spend key establishment rounds - - for (const auto& key: m_multisig_derivations) - derivations.erase(key); - - // Deriving multisig keys (set of Mi = b * Bi) according to DH from other participants' multisig keys. - auto new_derivations = cryptonote::generate_multisig_derivations(get_account().get_keys(), std::vector(derivations.begin(), derivations.end())); - - std::string extra_multisig_info; - if (m_multisig_rounds_passed == multisig_rounds_required(m_multisig_signers.size(), m_multisig_threshold) - 2) // next round is last - { - // Next round is last therefore we are performing secret spend establishment round as described above. - MINFO("Creating spend key..."); - - // Calculating our secret multisig keys by hashing our public multisig keys. - auto multisig_keys = cryptonote::calculate_multisig_keys(std::vector(new_derivations.begin(), new_derivations.end())); - // And summing it to get personal secret spend key - crypto::secret_key spend_skey = cryptonote::calculate_multisig_signer_key(multisig_keys); - - m_account.make_multisig(m_account.get_keys().m_view_secret_key, spend_skey, rct::rct2pk(rct::identity()), multisig_keys); - - // Packing public multisig keys to exchange with others and calculate common public spend key in the last round - extra_multisig_info = pack_multisignature_keys(MULTISIG_EXTRA_INFO_MAGIC, secret_keys_to_public_keys(multisig_keys), spend_skey); - } - else - { - // This is just middle round - MINFO("Preparing keys for next exchange round..."); - extra_multisig_info = pack_multisignature_keys(MULTISIG_EXTRA_INFO_MAGIC, new_derivations, m_account.get_keys().m_spend_secret_key); - m_multisig_derivations = new_derivations; - } - - ++m_multisig_rounds_passed; - + // wallet/file relationship if (!m_wallet_file.empty()) create_keys_file(m_wallet_file, false, password, boost::filesystem::exists(m_wallet_file + ".address.txt")); - return extra_multisig_info; + return multisig_account.get_next_kex_round_msg(); } - -void wallet2::unpack_multisig_info(const std::vector& info, - std::vector &public_keys, - std::vector &secret_keys) const +//---------------------------------------------------------------------------------------------------- +std::string wallet2::get_multisig_first_kex_msg() const { - // parse all multisig info - public_keys.resize(info.size()); - secret_keys.resize(info.size()); - for (size_t i = 0; i < info.size(); ++i) - { - THROW_WALLET_EXCEPTION_IF(!verify_multisig_info(info[i], secret_keys[i], public_keys[i]), - error::wallet_internal_error, "Bad multisig info: " + info[i]); - } + // create multisig account + multisig::multisig_account multisig_account{ + // k_base = H(normal private spend key) + multisig::get_multisig_blinded_secret_key(get_account().get_keys().m_spend_secret_key), + // k_view = H(normal private view key) + multisig::get_multisig_blinded_secret_key(get_account().get_keys().m_view_secret_key) + }; - // remove duplicates - for (size_t i = 0; i < secret_keys.size(); ++i) - { - for (size_t j = i + 1; j < secret_keys.size(); ++j) - { - if (rct::sk2rct(secret_keys[i]) == rct::sk2rct(secret_keys[j])) - { - MDEBUG("Duplicate key found, ignoring"); - secret_keys[j] = secret_keys.back(); - public_keys[j] = public_keys.back(); - secret_keys.pop_back(); - public_keys.pop_back(); - --j; - } - } - } - - // people may include their own, weed it out - const crypto::secret_key local_skey = cryptonote::get_multisig_blinded_secret_key(get_account().get_keys().m_view_secret_key); - const crypto::public_key local_pkey = get_multisig_signer_public_key(get_account().get_keys().m_spend_secret_key); - for (size_t i = 0; i < secret_keys.size(); ++i) - { - if (secret_keys[i] == local_skey) - { - MDEBUG("Local key is present, ignoring"); - secret_keys[i] = secret_keys.back(); - public_keys[i] = public_keys.back(); - secret_keys.pop_back(); - public_keys.pop_back(); - --i; - } - else - { - THROW_WALLET_EXCEPTION_IF(public_keys[i] == local_pkey, error::wallet_internal_error, - "Found local spend public key, but not local view secret key - something very weird"); - } - } + return multisig_account.get_next_kex_round_msg(); } - -std::string wallet2::make_multisig(const epee::wipeable_string &password, - const std::vector &info, - uint32_t threshold) -{ - std::vector secret_keys(info.size()); - std::vector public_keys(info.size()); - unpack_multisig_info(info, public_keys, secret_keys); - return make_multisig(password, secret_keys, public_keys, threshold); -} - -bool wallet2::finalize_multisig(const epee::wipeable_string &password, const std::unordered_set &pkeys, std::vector signers) -{ - bool ready; - uint32_t threshold, total; - if (!multisig(&ready, &threshold, &total)) - { - MERROR("This is not a multisig wallet"); - return false; - } - if (ready) - { - MERROR("This multisig wallet is already finalized"); - return false; - } - if (threshold + 1 != total) - { - MERROR("finalize_multisig should only be used for N-1/N wallets, use exchange_multisig_keys instead"); - return false; - } - exchange_multisig_keys(password, pkeys, signers); - return true; -} - -bool wallet2::unpack_extra_multisig_info(const std::vector& info, - std::vector &signers, - std::unordered_set &pkeys) const -{ - // parse all multisig info - signers.resize(info.size(), crypto::null_pkey); - for (size_t i = 0; i < info.size(); ++i) - { - if (!verify_extra_multisig_info(info[i], pkeys, signers[i])) - { - return false; - } - } - - return true; -} - -bool wallet2::finalize_multisig(const epee::wipeable_string &password, const std::vector &info) -{ - std::unordered_set public_keys; - std::vector signers; - if (!unpack_extra_multisig_info(info, signers, public_keys)) - { - MERROR("Bad multisig info"); - return false; - } - - return finalize_multisig(password, public_keys, signers); -} - -std::string wallet2::get_multisig_info() const -{ - // It's a signed package of private view key and public spend key - const crypto::secret_key skey = cryptonote::get_multisig_blinded_secret_key(get_account().get_keys().m_view_secret_key); - const crypto::public_key pkey = get_multisig_signer_public_key(get_account().get_keys().m_spend_secret_key); - crypto::hash hash; - - std::string data; - data += std::string((const char *)&skey, sizeof(crypto::secret_key)); - data += std::string((const char *)&pkey, sizeof(crypto::public_key)); - - data.resize(data.size() + sizeof(crypto::signature)); - crypto::cn_fast_hash(data.data(), data.size() - sizeof(signature), hash); - crypto::signature &signature = *(crypto::signature*)&data[data.size() - sizeof(crypto::signature)]; - crypto::generate_signature(hash, pkey, get_multisig_blinded_secret_key(get_account().get_keys().m_spend_secret_key), signature); - - return std::string("MultisigV1") + tools::base58::encode(data); -} - -bool wallet2::verify_multisig_info(const std::string &data, crypto::secret_key &skey, crypto::public_key &pkey) -{ - const size_t header_len = strlen("MultisigV1"); - if (data.size() < header_len || data.substr(0, header_len) != "MultisigV1") - { - MERROR("Multisig info header check error"); - return false; - } - std::string decoded; - if (!tools::base58::decode(data.substr(header_len), decoded)) - { - MERROR("Multisig info decoding error"); - return false; - } - if (decoded.size() != sizeof(crypto::secret_key) + sizeof(crypto::public_key) + sizeof(crypto::signature)) - { - MERROR("Multisig info is corrupt"); - return false; - } - - size_t offset = 0; - skey = *(const crypto::secret_key*)(decoded.data() + offset); - offset += sizeof(skey); - pkey = *(const crypto::public_key*)(decoded.data() + offset); - offset += sizeof(pkey); - const crypto::signature &signature = *(const crypto::signature*)(decoded.data() + offset); - - crypto::hash hash; - crypto::cn_fast_hash(decoded.data(), decoded.size() - sizeof(signature), hash); - if (!crypto::check_signature(hash, pkey, signature)) - { - MERROR("Multisig info signature is invalid"); - return false; - } - - return true; -} - -bool wallet2::verify_extra_multisig_info(const std::string &data, std::unordered_set &pkeys, crypto::public_key &signer) -{ - if (data.size() < MULTISIG_EXTRA_INFO_MAGIC.size() || data.substr(0, MULTISIG_EXTRA_INFO_MAGIC.size()) != MULTISIG_EXTRA_INFO_MAGIC) - { - MERROR("Multisig info header check error"); - return false; - } - std::string decoded; - if (!tools::base58::decode(data.substr(MULTISIG_EXTRA_INFO_MAGIC.size()), decoded)) - { - MERROR("Multisig info decoding error"); - return false; - } - if (decoded.size() < sizeof(crypto::public_key) + sizeof(crypto::signature)) - { - MERROR("Multisig info is corrupt"); - return false; - } - if ((decoded.size() - (sizeof(crypto::public_key) + sizeof(crypto::signature))) % sizeof(crypto::public_key)) - { - MERROR("Multisig info is corrupt"); - return false; - } - - const size_t n_keys = (decoded.size() - (sizeof(crypto::public_key) + sizeof(crypto::signature))) / sizeof(crypto::public_key); - size_t offset = 0; - signer = *(const crypto::public_key*)(decoded.data() + offset); - offset += sizeof(signer); - const crypto::signature &signature = *(const crypto::signature*)(decoded.data() + offset + n_keys * sizeof(crypto::public_key)); - - crypto::hash hash; - crypto::cn_fast_hash(decoded.data(), decoded.size() - sizeof(signature), hash); - if (!crypto::check_signature(hash, signer, signature)) - { - MERROR("Multisig info signature is invalid"); - return false; - } - - for (size_t n = 0; n < n_keys; ++n) - { - crypto::public_key mspk = *(const crypto::public_key*)(decoded.data() + offset); - pkeys.insert(mspk); - offset += sizeof(mspk); - } - - return true; -} - +//---------------------------------------------------------------------------------------------------- bool wallet2::multisig(bool *ready, uint32_t *threshold, uint32_t *total) const { if (!m_multisig) @@ -5402,7 +5109,7 @@ bool wallet2::multisig(bool *ready, uint32_t *threshold, uint32_t *total) const *ready = !(get_account().get_keys().m_account_address.m_spend_public_key == rct::rct2pk(rct::identity())); return true; } - +//---------------------------------------------------------------------------------------------------- bool wallet2::has_multisig_partial_key_images() const { if (!m_multisig) @@ -5412,7 +5119,7 @@ bool wallet2::has_multisig_partial_key_images() const return true; return false; } - +//---------------------------------------------------------------------------------------------------- bool wallet2::has_unknown_key_images() const { for (const auto &td: m_transfers) @@ -13218,13 +12925,6 @@ size_t wallet2::import_outputs_from_str(const std::string &outputs_st) return imported_outputs; } //---------------------------------------------------------------------------------------------------- -crypto::public_key wallet2::get_multisig_signer_public_key(const crypto::secret_key &spend_skey) const -{ - crypto::public_key pkey; - crypto::secret_key_to_public_key(get_multisig_blinded_secret_key(spend_skey), pkey); - return pkey; -} -//---------------------------------------------------------------------------------------------------- crypto::public_key wallet2::get_multisig_signer_public_key() const { CHECK_AND_ASSERT_THROW_MES(m_multisig, "Wallet is not multisig"); @@ -13268,7 +12968,7 @@ 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; - cryptonote::generate_multisig_LR(m_transfers[n].get_public_key(), rct::rct2sk(kLRki.k), (crypto::public_key&)kLRki.L, (crypto::public_key&)kLRki.R); + multisig::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; } @@ -13316,7 +13016,7 @@ crypto::key_image wallet2::get_multisig_composite_key_image(size_t n) const for (const auto &info: td.m_multisig_info) for (const auto &pki: info.m_partial_key_images) pkis.push_back(pki); - bool r = cryptonote::generate_multisig_composite_key_image(get_account().get_keys(), m_subaddresses, td.get_public_key(), tx_key, additional_tx_keys, td.m_internal_output_index, pkis, ki); + bool r = multisig::generate_multisig_composite_key_image(get_account().get_keys(), m_subaddresses, td.get_public_key(), tx_key, additional_tx_keys, td.m_internal_output_index, pkis, ki); THROW_WALLET_EXCEPTION_IF(!r, error::wallet_internal_error, "Failed to generate key image"); return ki; } @@ -13339,7 +13039,7 @@ cryptonote::blobdata wallet2::export_multisig() for (size_t m = 0; m < get_account().get_multisig_keys().size(); ++m) { // we want to export the partial key image, not the full one, so we can't use td.m_key_image - bool r = generate_multisig_key_image(get_account().get_keys(), m, td.get_public_key(), ki); + bool r = multisig::generate_multisig_key_image(get_account().get_keys(), m, td.get_public_key(), ki); CHECK_AND_ASSERT_THROW_MES(r, "Failed to generate key image"); info[n].m_partial_key_images.push_back(ki); } diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h index d72a90101..8d54ec20d 100644 --- a/src/wallet/wallet2.h +++ b/src/wallet/wallet2.h @@ -757,45 +757,20 @@ private: * to other participants */ std::string make_multisig(const epee::wipeable_string &password, - const std::vector &info, - uint32_t threshold); + const std::vector &kex_messages, + const std::uint32_t threshold); /*! - * \brief Creates a multisig wallet + * \brief Increment the multisig key exchange round * \return empty if done, non empty if we need to send another string * to other participants */ - std::string make_multisig(const epee::wipeable_string &password, - const std::vector &view_keys, - const std::vector &spend_keys, - uint32_t threshold); std::string exchange_multisig_keys(const epee::wipeable_string &password, - const std::vector &info); + const std::vector &kex_messages); /*! - * \brief Any but first round of keys exchange + * \brief Get initial message to start multisig key exchange (before 'make_multisig()' is called) + * \return string to send to other participants */ - std::string exchange_multisig_keys(const epee::wipeable_string &password, - std::unordered_set pkeys, - std::vector signers); - /*! - * \brief Finalizes creation of a multisig wallet - */ - bool finalize_multisig(const epee::wipeable_string &password, const std::vector &info); - /*! - * \brief Finalizes creation of a multisig wallet - */ - bool finalize_multisig(const epee::wipeable_string &password, const std::unordered_set &pkeys, std::vector signers); - /*! - * Get a packaged multisig information string - */ - std::string get_multisig_info() const; - /*! - * Verifies and extracts keys from a packaged multisig information string - */ - static bool verify_multisig_info(const std::string &data, crypto::secret_key &skey, crypto::public_key &pkey); - /*! - * Verifies and extracts keys from a packaged multisig information string - */ - static bool verify_extra_multisig_info(const std::string &data, std::unordered_set &pkeys, crypto::public_key &signer); + std::string get_multisig_first_kex_msg() const; /*! * Export multisig info * This will generate and remember new k values @@ -1472,7 +1447,6 @@ private: void set_attribute(const std::string &key, const std::string &value); bool get_attribute(const std::string &key, std::string &value) const; - crypto::public_key get_multisig_signer_public_key(const crypto::secret_key &spend_skey) const; crypto::public_key get_multisig_signer_public_key() const; crypto::public_key get_multisig_signing_public_key(size_t idx) const; crypto::public_key get_multisig_signing_public_key(const crypto::secret_key &skey) const; @@ -1635,12 +1609,6 @@ private: bool get_rct_distribution(uint64_t &start_height, std::vector &distribution); uint64_t get_segregation_fork_height() const; - void unpack_multisig_info(const std::vector& info, - std::vector &public_keys, - std::vector &secret_keys) const; - bool unpack_extra_multisig_info(const std::vector& info, - std::vector &signers, - std::unordered_set &pkeys) const; void cache_tx_data(const cryptonote::transaction& tx, const crypto::hash &txid, tx_cache_data &tx_cache_data) const; std::shared_ptr, size_t>> create_output_tracker_cache() const; diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp index f324f8c72..b1f2a3ca2 100644 --- a/src/wallet/wallet_rpc_server.cpp +++ b/src/wallet/wallet_rpc_server.cpp @@ -3879,7 +3879,7 @@ namespace tools return false; } - res.multisig_info = m_wallet->get_multisig_info(); + res.multisig_info = m_wallet->get_multisig_first_kex_msg(); return true; } //------------------------------------------------------------------------------------------------------------------------------ @@ -4010,7 +4010,7 @@ namespace tools catch (const std::exception &e) { er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR; - er.message = "Error calling import_multisig"; + er.message = std::string{"Error calling import_multisig: "} + e.what(); return false; } @@ -4035,53 +4035,7 @@ namespace tools //------------------------------------------------------------------------------------------------------------------------------ bool wallet_rpc_server::on_finalize_multisig(const wallet_rpc::COMMAND_RPC_FINALIZE_MULTISIG::request& req, wallet_rpc::COMMAND_RPC_FINALIZE_MULTISIG::response& res, epee::json_rpc::error& er, const connection_context *ctx) { - if (!m_wallet) return not_open(er); - if (m_restricted) - { - er.code = WALLET_RPC_ERROR_CODE_DENIED; - er.message = "Command unavailable in restricted mode."; - return false; - } - bool ready; - uint32_t threshold, total; - if (!m_wallet->multisig(&ready, &threshold, &total)) - { - er.code = WALLET_RPC_ERROR_CODE_NOT_MULTISIG; - er.message = "This wallet is not multisig"; - return false; - } - if (ready) - { - er.code = WALLET_RPC_ERROR_CODE_ALREADY_MULTISIG; - er.message = "This wallet is multisig, and already finalized"; - return false; - } - - if (req.multisig_info.size() < 1 || req.multisig_info.size() > total) - { - er.code = WALLET_RPC_ERROR_CODE_THRESHOLD_NOT_REACHED; - er.message = "Needs multisig info from more participants"; - return false; - } - - try - { - if (!m_wallet->finalize_multisig(req.password, req.multisig_info)) - { - er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR; - er.message = "Error calling finalize_multisig"; - return false; - } - } - catch (const std::exception &e) - { - er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR; - er.message = std::string("Error calling finalize_multisig: ") + e.what(); - return false; - } - res.address = m_wallet->get_account().get_public_address_str(m_wallet->nettype()); - - return true; + return false; } //------------------------------------------------------------------------------------------------------------------------------ bool wallet_rpc_server::on_exchange_multisig_keys(const wallet_rpc::COMMAND_RPC_EXCHANGE_MULTISIG_KEYS::request& req, wallet_rpc::COMMAND_RPC_EXCHANGE_MULTISIG_KEYS::response& res, epee::json_rpc::error& er, const connection_context *ctx) @@ -4109,7 +4063,7 @@ namespace tools return false; } - if (req.multisig_info.size() < 1 || req.multisig_info.size() > total) + if (req.multisig_info.size() + 1 < total) { er.code = WALLET_RPC_ERROR_CODE_THRESHOLD_NOT_REACHED; er.message = "Needs multisig info from more participants"; diff --git a/src/wallet/wallet_rpc_server_commands_defs.h b/src/wallet/wallet_rpc_server_commands_defs.h index 302ac7dc4..6d59ce966 100644 --- a/src/wallet/wallet_rpc_server_commands_defs.h +++ b/src/wallet/wallet_rpc_server_commands_defs.h @@ -2459,24 +2459,17 @@ namespace wallet_rpc struct COMMAND_RPC_FINALIZE_MULTISIG { + // NOP struct request_t { - std::string password; - std::vector multisig_info; - BEGIN_KV_SERIALIZE_MAP() - KV_SERIALIZE(password) - KV_SERIALIZE(multisig_info) END_KV_SERIALIZE_MAP() }; typedef epee::misc_utils::struct_init request; struct response_t { - std::string address; - BEGIN_KV_SERIALIZE_MAP() - KV_SERIALIZE(address) END_KV_SERIALIZE_MAP() }; typedef epee::misc_utils::struct_init response; diff --git a/tests/core_tests/chaingen.h b/tests/core_tests/chaingen.h index a5fd35028..5807084a4 100644 --- a/tests/core_tests/chaingen.h +++ b/tests/core_tests/chaingen.h @@ -840,7 +840,7 @@ inline bool do_replay_file(const std::string& filename) { \ for (size_t msidx = 0; msidx < total; ++msidx) \ account[msidx].generate(); \ - make_multisig_accounts(account, threshold); \ + CHECK_AND_ASSERT_MES(make_multisig_accounts(account, threshold), false, "Failed to make multisig accounts."); \ } while(0) #define MAKE_ACCOUNT(VEC_EVENTS, account) \ diff --git a/tests/core_tests/multisig.cpp b/tests/core_tests/multisig.cpp index f098e1bce..73bc1f104 100644 --- a/tests/core_tests/multisig.cpp +++ b/tests/core_tests/multisig.cpp @@ -28,98 +28,88 @@ // // 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 "common/apply_permutation.h" #include "chaingen.h" #include "multisig.h" + +#include "common/apply_permutation.h" +#include "crypto/crypto.h" +#include "cryptonote_basic/cryptonote_basic.h" #include "device/device.hpp" +#include "multisig/multisig.h" +#include "multisig/multisig_account.h" +#include "multisig/multisig_kex_msg.h" +#include "ringct/rctOps.h" +#include "ringct/rctSigs.h" + using namespace epee; using namespace crypto; using namespace cryptonote; +using namespace multisig; //#define NO_MULTISIG -void make_multisig_accounts(std::vector& account, uint32_t threshold) +static bool make_multisig_accounts(std::vector &accounts, const uint32_t threshold) { - std::vector all_view_keys; - std::vector> derivations(account.size()); - //storage for all set of multisig derivations and spend public key (in first round) - std::unordered_set exchanging_keys; + CHECK_AND_ASSERT_MES(accounts.size() > 0, false, "Invalid multisig scheme"); - for (size_t msidx = 0; msidx < account.size(); ++msidx) + std::vector multisig_accounts; + std::vector signers; + std::vector round_msgs; + multisig_accounts.reserve(accounts.size()); + signers.reserve(accounts.size()); + round_msgs.reserve(accounts.size()); + + // create multisig accounts + for (std::size_t account_index{0}; account_index < accounts.size(); ++account_index) { - crypto::secret_key vkh = cryptonote::get_multisig_blinded_secret_key(account[msidx].get_keys().m_view_secret_key); - all_view_keys.push_back(vkh); + // create account and collect signer + multisig_accounts.emplace_back( + multisig_account{ + get_multisig_blinded_secret_key(accounts[account_index].get_keys().m_spend_secret_key), + get_multisig_blinded_secret_key(accounts[account_index].get_keys().m_view_secret_key) + } + ); - crypto::secret_key skh = cryptonote::get_multisig_blinded_secret_key(account[msidx].get_keys().m_spend_secret_key); - crypto::public_key pskh; - crypto::secret_key_to_public_key(skh, pskh); + signers.emplace_back(multisig_accounts.back().get_base_pubkey()); - derivations[msidx].push_back(pskh); - exchanging_keys.insert(pskh); + // collect account's first kex msg + round_msgs.emplace_back(multisig_accounts.back().get_next_kex_round_msg()); } - uint32_t roundsTotal = 1; - if (threshold < account.size()) - roundsTotal = account.size() - threshold; - - //secret multisig keys of every account - std::vector> multisig_keys(account.size()); - std::vector spend_skey(account.size()); - std::vector spend_pkey(account.size()); - for (uint32_t round = 0; round < roundsTotal; ++round) + // initialize accounts and collect kex messages for the next round + std::vector temp_round_msgs(multisig_accounts.size()); + for (std::size_t account_index{0}; account_index < accounts.size(); ++account_index) { - std::unordered_set roundKeys; - for (size_t msidx = 0; msidx < account.size(); ++msidx) + multisig_accounts[account_index].initialize_kex(threshold, signers, round_msgs); + + if (!multisig_accounts[account_index].multisig_is_ready()) + temp_round_msgs[account_index] = multisig_accounts[account_index].get_next_kex_round_msg(); + } + + // perform key exchange rounds + while (!multisig_accounts[0].multisig_is_ready()) + { + round_msgs = temp_round_msgs; + + for (std::size_t account_index{0}; account_index < multisig_accounts.size(); ++account_index) { - // subtracting one's keys from set of all unique keys is the same as key exchange - auto myKeys = exchanging_keys; - for (const auto& d: derivations[msidx]) - myKeys.erase(d); + multisig_accounts[account_index].kex_update(round_msgs); - if (threshold == account.size()) - { - cryptonote::generate_multisig_N_N(account[msidx].get_keys(), std::vector(myKeys.begin(), myKeys.end()), multisig_keys[msidx], (rct::key&)spend_skey[msidx], (rct::key&)spend_pkey[msidx]); - } - else - { - derivations[msidx] = cryptonote::generate_multisig_derivations(account[msidx].get_keys(), std::vector(myKeys.begin(), myKeys.end())); - roundKeys.insert(derivations[msidx].begin(), derivations[msidx].end()); - } + if (!multisig_accounts[account_index].multisig_is_ready()) + temp_round_msgs[account_index] = multisig_accounts[account_index].get_next_kex_round_msg(); } - - exchanging_keys = roundKeys; - roundKeys.clear(); } - std::unordered_set all_multisig_keys; - for (size_t msidx = 0; msidx < account.size(); ++msidx) + // update accounts post key exchange + for (std::size_t account_index{0}; account_index < accounts.size(); ++account_index) { - std::unordered_set view_keys(all_view_keys.begin(), all_view_keys.end()); - view_keys.erase(all_view_keys[msidx]); - - crypto::secret_key view_skey = cryptonote::generate_multisig_view_secret_key(account[msidx].get_keys().m_view_secret_key, std::vector(view_keys.begin(), view_keys.end())); - if (threshold < account.size()) - { - multisig_keys[msidx] = cryptonote::calculate_multisig_keys(derivations[msidx]); - spend_skey[msidx] = cryptonote::calculate_multisig_signer_key(multisig_keys[msidx]); - } - account[msidx].make_multisig(view_skey, spend_skey[msidx], spend_pkey[msidx], multisig_keys[msidx]); - for (const auto &k: multisig_keys[msidx]) { - all_multisig_keys.insert(rct::rct2pk(rct::scalarmultBase(rct::sk2rct(k)))); - } + accounts[account_index].make_multisig(multisig_accounts[account_index].get_common_privkey(), + multisig_accounts[account_index].get_base_privkey(), + multisig_accounts[account_index].get_multisig_pubkey(), + multisig_accounts[account_index].get_multisig_privkeys()); } - if (threshold < account.size()) - { - std::vector public_keys(std::vector(all_multisig_keys.begin(), all_multisig_keys.end())); - crypto::public_key spend_pkey = cryptonote::generate_multisig_M_N_spend_public_key(public_keys); - - for (size_t msidx = 0; msidx < account.size(); ++msidx) - account[msidx].finalize_multisig(spend_pkey); - } + return true; } //---------------------------------------------------------------------------------------------------------------------- @@ -238,13 +228,13 @@ bool gen_multisig_tx_validation_base::generate_with(std::vector -#include "wallet/wallet2.h" - static const struct { const char *address; @@ -86,59 +90,145 @@ static void make_wallet(unsigned int idx, tools::wallet2 &wallet) } } -static std::vector exchange_round(std::vector& wallets, const std::vector& mis) +static std::vector exchange_round(std::vector& wallets, const std::vector& infos) { std::vector new_infos; - for (size_t i = 0; i < wallets.size(); ++i) { - new_infos.push_back(wallets[i].exchange_multisig_keys("", mis)); + new_infos.reserve(infos.size()); + + for (size_t i = 0; i < wallets.size(); ++i) + { + new_infos.push_back(wallets[i].exchange_multisig_keys("", infos)); } return new_infos; } +static void check_results(const std::vector &intermediate_infos, + std::vector& wallets, + std::uint32_t M) +{ + // check results + std::unordered_set unique_privkeys; + rct::key composite_pubkey = rct::identity(); + + wallets[0].decrypt_keys(""); + crypto::public_key spend_pubkey = wallets[0].get_account().get_keys().m_account_address.m_spend_public_key; + crypto::secret_key view_privkey = wallets[0].get_account().get_keys().m_view_secret_key; + crypto::public_key view_pubkey; + EXPECT_TRUE(crypto::secret_key_to_public_key(view_privkey, view_pubkey)); + wallets[0].encrypt_keys(""); + + for (size_t i = 0; i < wallets.size(); ++i) + { + EXPECT_TRUE(intermediate_infos[i].empty()); + bool ready; + uint32_t threshold, total; + EXPECT_TRUE(wallets[i].multisig(&ready, &threshold, &total)); + EXPECT_TRUE(ready); + EXPECT_TRUE(threshold == M); + EXPECT_TRUE(total == wallets.size()); + + wallets[i].decrypt_keys(""); + + if (i != 0) + { + // "equals" is transitive relation so we need only to compare first wallet's address to each others' addresses. + // no need to compare 0's address with itself. + EXPECT_TRUE(wallets[0].get_account().get_public_address_str(cryptonote::TESTNET) == + wallets[i].get_account().get_public_address_str(cryptonote::TESTNET)); + + EXPECT_EQ(spend_pubkey, wallets[i].get_account().get_keys().m_account_address.m_spend_public_key); + EXPECT_EQ(view_privkey, wallets[i].get_account().get_keys().m_view_secret_key); + EXPECT_EQ(view_pubkey, wallets[i].get_account().get_keys().m_account_address.m_view_public_key); + } + + // sum together unique multisig keys + for (const auto &privkey : wallets[i].get_account().get_keys().m_multisig_keys) + { + EXPECT_NE(privkey, crypto::null_skey); + + if (unique_privkeys.find(privkey) == unique_privkeys.end()) + { + unique_privkeys.insert(privkey); + crypto::public_key pubkey; + crypto::secret_key_to_public_key(privkey, pubkey); + EXPECT_NE(privkey, crypto::null_skey); + EXPECT_NE(pubkey, crypto::null_pkey); + EXPECT_NE(pubkey, rct::rct2pk(rct::identity())); + rct::addKeys(composite_pubkey, composite_pubkey, rct::pk2rct(pubkey)); + } + } + wallets[i].encrypt_keys(""); + } + + // final key via sums should equal the wallets' public spend key + wallets[0].decrypt_keys(""); + EXPECT_EQ(wallets[0].get_account().get_keys().m_account_address.m_spend_public_key, rct::rct2pk(composite_pubkey)); + wallets[0].encrypt_keys(""); +} + static void make_wallets(std::vector& wallets, unsigned int M) { ASSERT_TRUE(wallets.size() > 1 && wallets.size() <= KEYS_COUNT); ASSERT_TRUE(M <= wallets.size()); + std::uint32_t rounds_required = multisig::multisig_kex_rounds_required(wallets.size(), M); + std::uint32_t rounds_complete{0}; - std::vector mis(wallets.size()); + // initialize wallets, get first round multisig kex msgs + std::vector initial_infos(wallets.size()); - for (size_t i = 0; i < wallets.size(); ++i) { + for (size_t i = 0; i < wallets.size(); ++i) + { make_wallet(i, wallets[i]); wallets[i].decrypt_keys(""); - mis[i] = wallets[i].get_multisig_info(); + initial_infos[i] = wallets[i].get_multisig_first_kex_msg(); wallets[i].encrypt_keys(""); } - for (auto& wallet: wallets) { + // wallets should not be multisig yet + for (const auto &wallet: wallets) + { ASSERT_FALSE(wallet.multisig()); } - std::vector mxis; - for (size_t i = 0; i < wallets.size(); ++i) { - // it's ok to put all of multisig keys in this function. it throws in case of error - mxis.push_back(wallets[i].make_multisig("", mis, M)); + // make wallets multisig, get second round kex messages (if appropriate) + std::vector intermediate_infos(wallets.size()); + + for (size_t i = 0; i < wallets.size(); ++i) + { + intermediate_infos[i] = wallets[i].make_multisig("", initial_infos, M); } - while (!mxis[0].empty()) { - mxis = exchange_round(wallets, mxis); + ++rounds_complete; + + // perform kex rounds until kex is complete + while (!intermediate_infos[0].empty()) + { + bool ready{false}; + wallets[0].multisig(&ready); + EXPECT_FALSE(ready); + + intermediate_infos = exchange_round(wallets, intermediate_infos); + + ++rounds_complete; } - for (size_t i = 0; i < wallets.size(); ++i) { - ASSERT_TRUE(mxis[i].empty()); - bool ready; - uint32_t threshold, total; - ASSERT_TRUE(wallets[i].multisig(&ready, &threshold, &total)); - ASSERT_TRUE(ready); - ASSERT_TRUE(threshold == M); - ASSERT_TRUE(total == wallets.size()); + EXPECT_EQ(rounds_required, rounds_complete); - if (i != 0) { - // "equals" is transitive relation so we need only to compare first wallet's address to each others' addresses. no need to compare 0's address with itself. - ASSERT_TRUE(wallets[0].get_account().get_public_address_str(cryptonote::TESTNET) == wallets[i].get_account().get_public_address_str(cryptonote::TESTNET)); - } - } + check_results(intermediate_infos, wallets, M); +} + +TEST(multisig, make_1_2) +{ + std::vector wallets(2); + make_wallets(wallets, 1); +} + +TEST(multisig, make_1_3) +{ + std::vector wallets(3); + make_wallets(wallets, 1); } TEST(multisig, make_2_2) @@ -165,8 +255,88 @@ TEST(multisig, make_2_4) make_wallets(wallets, 2); } -TEST(multisig, make_2_5) +TEST(multisig, multisig_kex_msg) { - std::vector wallets(5); - make_wallets(wallets, 2); + using namespace multisig; + + crypto::public_key pubkey1; + crypto::public_key pubkey2; + crypto::public_key pubkey3; + crypto::secret_key_to_public_key(rct::rct2sk(rct::skGen()), pubkey1); + crypto::secret_key_to_public_key(rct::rct2sk(rct::skGen()), pubkey2); + crypto::secret_key_to_public_key(rct::rct2sk(rct::skGen()), pubkey3); + + crypto::secret_key signing_skey = rct::rct2sk(rct::skGen()); + crypto::public_key signing_pubkey; + while(!crypto::secret_key_to_public_key(signing_skey, signing_pubkey)) + { + signing_skey = rct::rct2sk(rct::skGen()); + } + + crypto::secret_key ancillary_skey = rct::rct2sk(rct::skGen()); + while (ancillary_skey == crypto::null_skey) + ancillary_skey = rct::rct2sk(rct::skGen()); + + // misc. edge cases + EXPECT_NO_THROW((multisig_kex_msg{})); + EXPECT_ANY_THROW((multisig_kex_msg{multisig_kex_msg{}.get_msg()})); + EXPECT_ANY_THROW((multisig_kex_msg{"abc"})); + EXPECT_ANY_THROW((multisig_kex_msg{0, crypto::null_skey, std::vector{}, crypto::null_skey})); + EXPECT_ANY_THROW((multisig_kex_msg{1, crypto::null_skey, std::vector{}, crypto::null_skey})); + EXPECT_ANY_THROW((multisig_kex_msg{1, signing_skey, std::vector{}, crypto::null_skey})); + EXPECT_ANY_THROW((multisig_kex_msg{1, crypto::null_skey, std::vector{}, ancillary_skey})); + + // test that messages are both constructible and reversible + + // round 1 + EXPECT_NO_THROW((multisig_kex_msg{ + multisig_kex_msg{1, signing_skey, std::vector{}, ancillary_skey}.get_msg() + })); + EXPECT_NO_THROW((multisig_kex_msg{ + multisig_kex_msg{1, signing_skey, std::vector{pubkey1}, ancillary_skey}.get_msg() + })); + + // round 2 + EXPECT_NO_THROW((multisig_kex_msg{ + multisig_kex_msg{2, signing_skey, std::vector{pubkey1}, ancillary_skey}.get_msg() + })); + EXPECT_NO_THROW((multisig_kex_msg{ + multisig_kex_msg{2, signing_skey, std::vector{pubkey1}, crypto::null_skey}.get_msg() + })); + EXPECT_NO_THROW((multisig_kex_msg{ + multisig_kex_msg{2, signing_skey, std::vector{pubkey1, pubkey2}, ancillary_skey}.get_msg() + })); + EXPECT_NO_THROW((multisig_kex_msg{ + multisig_kex_msg{2, signing_skey, std::vector{pubkey1, pubkey2, pubkey3}, crypto::null_skey}.get_msg() + })); + + // test that keys can be recovered if stored in a message and the message's reverse + + // round 1 + multisig_kex_msg msg_rnd1{1, signing_skey, std::vector{pubkey1}, ancillary_skey}; + multisig_kex_msg msg_rnd1_reverse{msg_rnd1.get_msg()}; + EXPECT_EQ(msg_rnd1.get_round(), 1); + EXPECT_EQ(msg_rnd1.get_round(), msg_rnd1_reverse.get_round()); + EXPECT_EQ(msg_rnd1.get_signing_pubkey(), signing_pubkey); + EXPECT_EQ(msg_rnd1.get_signing_pubkey(), msg_rnd1_reverse.get_signing_pubkey()); + EXPECT_EQ(msg_rnd1.get_msg_pubkeys().size(), 0); + EXPECT_EQ(msg_rnd1.get_msg_pubkeys().size(), msg_rnd1_reverse.get_msg_pubkeys().size()); + EXPECT_EQ(msg_rnd1.get_msg_privkey(), ancillary_skey); + EXPECT_EQ(msg_rnd1.get_msg_privkey(), msg_rnd1_reverse.get_msg_privkey()); + + // round 2 + multisig_kex_msg msg_rnd2{2, signing_skey, std::vector{pubkey1, pubkey2}, ancillary_skey}; + multisig_kex_msg msg_rnd2_reverse{msg_rnd2.get_msg()}; + EXPECT_EQ(msg_rnd2.get_round(), 2); + EXPECT_EQ(msg_rnd2.get_round(), msg_rnd2_reverse.get_round()); + EXPECT_EQ(msg_rnd2.get_signing_pubkey(), signing_pubkey); + EXPECT_EQ(msg_rnd2.get_signing_pubkey(), msg_rnd2_reverse.get_signing_pubkey()); + ASSERT_EQ(msg_rnd2.get_msg_pubkeys().size(), 2); + ASSERT_EQ(msg_rnd2.get_msg_pubkeys().size(), msg_rnd2_reverse.get_msg_pubkeys().size()); + EXPECT_EQ(msg_rnd2.get_msg_pubkeys()[0], pubkey1); + EXPECT_EQ(msg_rnd2.get_msg_pubkeys()[1], pubkey2); + EXPECT_EQ(msg_rnd2.get_msg_pubkeys()[0], msg_rnd2_reverse.get_msg_pubkeys()[0]); + EXPECT_EQ(msg_rnd2.get_msg_pubkeys()[1], msg_rnd2_reverse.get_msg_pubkeys()[1]); + EXPECT_EQ(msg_rnd2.get_msg_privkey(), crypto::null_skey); + EXPECT_EQ(msg_rnd2.get_msg_privkey(), msg_rnd2_reverse.get_msg_privkey()); } diff --git a/utils/python-rpc/framework/wallet.py b/utils/python-rpc/framework/wallet.py index da49e9317..96d99a3c4 100644 --- a/utils/python-rpc/framework/wallet.py +++ b/utils/python-rpc/framework/wallet.py @@ -512,14 +512,12 @@ class Wallet(object): } return self.rpc.send_json_rpc_request(make_multisig) - def finalize_multisig(self, multisig_info, password = ''): + def finalize_multisig(self): finalize_multisig = { 'method': 'finalize_multisig', 'params' : { - 'multisig_info': multisig_info, - 'password': password, }, - 'jsonrpc': '2.0', + 'jsonrpc': '2.0', 'id': '0' } return self.rpc.send_json_rpc_request(finalize_multisig)