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multisig key exchange update and refactor

This commit is contained in:
koe 2021-08-02 23:27:43 -05:00
parent b58a9fb12e
commit e08abaa43f
30 changed files with 2224 additions and 952 deletions
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11
src/crypto/crypto.h
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@ -64,6 +64,11 @@ namespace crypto {
friend class crypto_ops; friend class crypto_ops;
}; };
POD_CLASS public_key_memsafe : epee::mlocked<tools::scrubbed<public_key>> {
public_key_memsafe() = default;
public_key_memsafe(const public_key &original) { memcpy(this->data, original.data, 32); }
};
using secret_key = epee::mlocked<tools::scrubbed<ec_scalar>>; using secret_key = epee::mlocked<tools::scrubbed<ec_scalar>>;
POD_CLASS public_keyV { POD_CLASS public_keyV {
@ -100,7 +105,7 @@ namespace crypto {
void random32_unbiased(unsigned char *bytes); void random32_unbiased(unsigned char *bytes);
static_assert(sizeof(ec_point) == 32 && sizeof(ec_scalar) == 32 && 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(key_derivation) == 32 && sizeof(key_image) == 32 &&
sizeof(signature) == 64, "Invalid structure size"); sizeof(signature) == 64, "Invalid structure size");
@ -310,9 +315,13 @@ namespace crypto {
const extern crypto::public_key null_pkey; const extern crypto::public_key null_pkey;
const extern crypto::secret_key null_skey; 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(public_key)
CRYPTO_MAKE_HASHABLE_CONSTANT_TIME(secret_key) CRYPTO_MAKE_HASHABLE_CONSTANT_TIME(secret_key)
CRYPTO_MAKE_HASHABLE_CONSTANT_TIME(public_key_memsafe)
CRYPTO_MAKE_HASHABLE(key_image) CRYPTO_MAKE_HASHABLE(key_image)
CRYPTO_MAKE_COMPARABLE(signature) CRYPTO_MAKE_COMPARABLE(signature)

5
src/cryptonote_basic/account.cpp
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@ -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); 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 const account_keys& account_base::get_keys() const
{ {
return m_keys; return m_keys;

1
src/cryptonote_basic/account.h
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@ -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_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); 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<crypto::secret_key> &multisig_keys); 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<crypto::secret_key> &multisig_keys);
void finalize_multisig(const crypto::public_key &spend_public_key);
const account_keys& get_keys() const; const account_keys& get_keys() const;
std::string get_public_address_str(network_type nettype) 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; std::string get_public_integrated_address_str(const crypto::hash8 &payment_id, network_type nettype) const;

21
src/cryptonote_basic/cryptonote_format_utils.cpp
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@ -306,7 +306,26 @@ namespace cryptonote
{ {
// derive secret key with subaddress - step 1: original CN derivation // derive secret key with subaddress - step 1: original CN derivation
crypto::secret_key scalar_step1; 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) // step 2: add Hs(a || index_major || index_minor)
crypto::secret_key subaddr_sk; crypto::secret_key subaddr_sk;

4
src/cryptonote_config.h
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@ -229,6 +229,7 @@ namespace config
const unsigned char HASH_KEY_RPC_PAYMENT_NONCE = 0x58; const unsigned char HASH_KEY_RPC_PAYMENT_NONCE = 0x58;
const unsigned char HASH_KEY_MEMORY = 'k'; 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[] = {'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_TXPROOF_V2[] = "TXPROOF_V2";
const unsigned char HASH_KEY_CLSAG_ROUND[] = "CLSAG_round"; 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_0[] = "CLSAG_agg_0";
@ -236,6 +237,9 @@ namespace config
const char HASH_KEY_MESSAGE_SIGNING[] = "MoneroMessageSignature"; const char HASH_KEY_MESSAGE_SIGNING[] = "MoneroMessageSignature";
const unsigned char HASH_KEY_MM_SLOT = 'm'; const unsigned char HASH_KEY_MM_SLOT = 'm';
// Multisig
const uint32_t MULTISIG_MAX_SIGNERS{16};
namespace testnet namespace testnet
{ {
uint64_t const CRYPTONOTE_PUBLIC_ADDRESS_BASE58_PREFIX = 53; uint64_t const CRYPTONOTE_PUBLIC_ADDRESS_BASE58_PREFIX = 53;

1
src/cryptonote_core/cryptonote_tx_utils.cpp
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@ -43,7 +43,6 @@ using namespace epee;
#include "crypto/crypto.h" #include "crypto/crypto.h"
#include "crypto/hash.h" #include "crypto/hash.h"
#include "ringct/rctSigs.h" #include "ringct/rctSigs.h"
#include "multisig/multisig.h"
using namespace crypto; using namespace crypto;

42
src/gen_multisig/gen_multisig.cpp
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@ -95,55 +95,35 @@ static bool generate_multisig(uint32_t threshold, uint32_t total, const std::str
} }
// gather the keys // gather the keys
std::vector<crypto::secret_key> sk(total); std::vector<std::string> first_round_msgs;
std::vector<crypto::public_key> pk(total); first_round_msgs.reserve(total);
for (size_t n = 0; n < total; ++n) for (size_t n = 0; n < total; ++n)
{ {
wallets[n]->decrypt_keys(pwd_container->password()); wallets[n]->decrypt_keys(pwd_container->password());
if (!tools::wallet2::verify_multisig_info(wallets[n]->get_multisig_info(), sk[n], pk[n]))
{ first_round_msgs.emplace_back(wallets[n]->get_multisig_first_kex_msg());
tools::fail_msg_writer() << genms::tr("Failed to verify multisig info");
return false;
}
wallets[n]->encrypt_keys(pwd_container->password()); wallets[n]->encrypt_keys(pwd_container->password());
} }
// make the wallets multisig // make the wallets multisig
std::vector<std::string> extra_info(total); std::vector<std::string> kex_msgs_intermediate(total);
std::stringstream ss; std::stringstream ss;
for (size_t n = 0; n < total; ++n) for (size_t n = 0; n < total; ++n)
{ {
std::string name = basename + "-" + std::to_string(n + 1); std::string name = basename + "-" + std::to_string(n + 1);
std::vector<crypto::secret_key> skn;
std::vector<crypto::public_key> pkn; kex_msgs_intermediate[n] = wallets[n]->make_multisig(pwd_container->password(), first_round_msgs, threshold);
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);
ss << " " << name << std::endl; ss << " " << name << std::endl;
} }
//exchange keys unless exchange_multisig_keys returns no extra info //exchange keys unless exchange_multisig_keys returns no extra info
while (!extra_info[0].empty()) while (!kex_msgs_intermediate[0].empty())
{ {
std::unordered_set<crypto::public_key> pkeys;
std::vector<crypto::public_key> signers(total);
for (size_t n = 0; n < total; ++n) for (size_t n = 0; n < total; ++n)
{ {
if (!tools::wallet2::verify_extra_multisig_info(extra_info[n], pkeys, signers[n])) kex_msgs_intermediate[n] = wallets[n]->exchange_multisig_keys(pwd_container->password(), kex_msgs_intermediate);
{
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);
} }
} }

9
src/multisig/CMakeLists.txt
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@ -27,12 +27,17 @@
# THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. # THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
set(multisig_sources set(multisig_sources
multisig.cpp) multisig.cpp
multisig_account.cpp
multisig_account_kex_impl.cpp
multisig_kex_msg.cpp)
set(multisig_headers) set(multisig_headers)
set(multisig_private_headers set(multisig_private_headers
multisig.h) multisig.h
multisig_account.h
multisig_kex_msg.h)
monero_private_headers(multisig monero_private_headers(multisig
${multisig_private_headers}) ${multisig_private_headers})

168
src/multisig/multisig.cpp
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@ -1,4 +1,4 @@
// Copyright (c) 2017-2020, The Monero Project // Copyright (c) 2017-2021, The Monero Project
// //
// All rights reserved. // All rights reserved.
// //
@ -26,29 +26,34 @@
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF // 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. // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <unordered_set>
#include "include_base_utils.h"
#include "crypto/crypto.h" #include "crypto/crypto.h"
#include "ringct/rctOps.h"
#include "cryptonote_basic/account.h" #include "cryptonote_basic/account.h"
#include "cryptonote_basic/cryptonote_format_utils.h" #include "cryptonote_basic/cryptonote_format_utils.h"
#include "multisig.h"
#include "cryptonote_config.h" #include "cryptonote_config.h"
#include "include_base_utils.h"
#include "multisig.h"
#include "ringct/rctOps.h"
#include <algorithm>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#undef MONERO_DEFAULT_LOG_CATEGORY #undef MONERO_DEFAULT_LOG_CATEGORY
#define MONERO_DEFAULT_LOG_CATEGORY "multisig" #define MONERO_DEFAULT_LOG_CATEGORY "multisig"
using namespace std; namespace multisig
namespace cryptonote
{ {
//----------------------------------------------------------------- //----------------------------------------------------------------------------------------------------------------------
crypto::secret_key get_multisig_blinded_secret_key(const crypto::secret_key &key) 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; rct::key multisig_salt;
static_assert(sizeof(rct::key) == sizeof(config::HASH_KEY_MULTISIG), "Hash domain separator is an unexpected size"); 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)); memcpy(multisig_salt.bytes, config::HASH_KEY_MULTISIG, sizeof(rct::key));
// private key = H(key, domain-sep)
rct::keyV data; rct::keyV data;
data.reserve(2); data.reserve(2);
data.push_back(rct::sk2rct(key)); data.push_back(rct::sk2rct(key));
@ -57,134 +62,79 @@ namespace cryptonote
memwipe(&data[0], sizeof(rct::key)); memwipe(&data[0], sizeof(rct::key));
return result; return result;
} }
//----------------------------------------------------------------- //----------------------------------------------------------------------------------------------------------------------
void generate_multisig_N_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey) bool generate_multisig_key_image(const cryptonote::account_keys &keys,
{ std::size_t multisig_key_index,
// the multisig spend public key is the sum of all spend public keys const crypto::public_key& out_key,
multisig_keys.clear(); crypto::key_image& ki)
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<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey)
{
multisig_keys.clear();
spend_pkey = rct::identity();
spend_skey = rct::zero();
// create all our composite private keys
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<crypto::public_key> generate_multisig_derivations(const account_keys &keys, const std::vector<crypto::public_key> &derivations)
{
std::vector<crypto::public_key> 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<crypto::secret_key>& 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<crypto::secret_key> calculate_multisig_keys(const std::vector<crypto::public_key>& derivations)
{
std::vector<crypto::secret_key> 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<crypto::secret_key> &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<crypto::public_key> &pkeys)
{
rct::key spend_public_key = rct::identity();
for (const auto &pk: pkeys)
{
rct::addKeys(spend_public_key, spend_public_key, rct::pk2rct(pk));
}
return rct::rct2pk(spend_public_key);
}
//-----------------------------------------------------------------
bool generate_multisig_key_image(const account_keys &keys, size_t multisig_key_index, const crypto::public_key& out_key, crypto::key_image& ki)
{ {
if (multisig_key_index >= keys.m_multisig_keys.size()) if (multisig_key_index >= keys.m_multisig_keys.size())
return false; return false;
crypto::generate_key_image(out_key, keys.m_multisig_keys[multisig_key_index], ki); crypto::generate_key_image(out_key, keys.m_multisig_keys[multisig_key_index], ki);
return true; 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)); rct::scalarmultBase((rct::key&)L, rct::sk2rct(k));
crypto::generate_key_image(pkey, k, (crypto::key_image&)R); crypto::generate_key_image(pkey, k, (crypto::key_image&)R);
} }
//----------------------------------------------------------------- //----------------------------------------------------------------------------------------------------------------------
bool generate_multisig_composite_key_image(const account_keys &keys, const std::unordered_map<crypto::public_key, subaddress_index>& subaddresses, const crypto::public_key& out_key, const crypto::public_key &tx_public_key, const std::vector<crypto::public_key>& additional_tx_public_keys, size_t real_output_index, const std::vector<crypto::key_image> &pkis, crypto::key_image &ki) bool generate_multisig_composite_key_image(const cryptonote::account_keys &keys,
const std::unordered_map<crypto::public_key, cryptonote::subaddress_index> &subaddresses,
const crypto::public_key &out_key,
const crypto::public_key &tx_public_key,
const std::vector<crypto::public_key> &additional_tx_public_keys,
std::size_t real_output_index,
const std::vector<crypto::key_image> &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; 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())) 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; return false;
std::unordered_set<crypto::key_image> used; std::unordered_set<crypto::key_image> 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; 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) if (!r)
return false; return false;
// this KI component is 'used' because it was included in the partial key image 'ki' above
used.insert(pki); used.insert(pki);
} }
// add the KI components from other participants to the partial KI
// if they not included yet
for (const auto &pki: pkis) for (const auto &pki: pkis)
{ {
if (used.find(pki) == used.end()) if (used.find(pki) == used.end())
{ {
// ignore components that have already been 'used'
used.insert(pki); used.insert(pki);
// KI_partial = KI_partial + KI_component[...]
rct::addKeys((rct::key&)ki, rct::ki2rct(ki), rct::ki2rct(pki)); 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; return true;
} }
//----------------------------------------------------------------- //----------------------------------------------------------------------------------------------------------------------
uint32_t multisig_rounds_required(uint32_t participants, uint32_t threshold) } //namespace multisig
{
CHECK_AND_ASSERT_THROW_MES(participants >= threshold, "participants must be greater or equal than threshold");
return participants - threshold + 1;
}
}

70
src/multisig/multisig.h
View File

@ -1,4 +1,4 @@
// Copyright (c) 2017-2020, The Monero Project // Copyright (c) 2017-2021, The Monero Project
// //
// All rights reserved. // All rights reserved.
// //
@ -28,44 +28,42 @@
#pragma once #pragma once
#include <vector>
#include <unordered_map>
#include "crypto/crypto.h" #include "crypto/crypto.h"
#include "cryptonote_basic/cryptonote_format_utils.h" #include "cryptonote_basic/cryptonote_format_utils.h"
#include "ringct/rctTypes.h" #include "ringct/rctTypes.h"
namespace cryptonote #include <unordered_map>
{ #include <unordered_set>
struct account_keys; #include <vector>
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); 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<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey);
void generate_multisig_N1_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey); bool generate_multisig_key_image(const cryptonote::account_keys &keys,
/** std::size_t multisig_key_index,
* @brief generate_multisig_derivations performs common DH key derivation. const crypto::public_key& out_key,
* 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. crypto::key_image& ki);
* this functions does the following: new multisig key = secret spend * public multisig key void generate_multisig_LR(const crypto::public_key pkey,
* @param keys - current wallet's keys const crypto::secret_key &k,
* @param derivations - public multisig keys of other participants crypto::public_key &L,
* @return new public multisig keys derived from previous round. This data needs to be exchange with other participants crypto::public_key &R);
*/ bool generate_multisig_composite_key_image(const cryptonote::account_keys &keys,
std::vector<crypto::public_key> generate_multisig_derivations(const account_keys &keys, const std::vector<crypto::public_key> &derivations); const std::unordered_map<crypto::public_key, cryptonote::subaddress_index> &subaddresses,
crypto::secret_key calculate_multisig_signer_key(const std::vector<crypto::secret_key>& derivations); const crypto::public_key &out_key,
/** const crypto::public_key &tx_public_key,
* @brief calculate_multisig_keys. Calculates secret multisig keys from others' participants ones as follows: mi = H(Mi) const std::vector<crypto::public_key> &additional_tx_public_keys,
* @param derivations - others' participants public multisig keys. std::size_t real_output_index,
* @return vector of current wallet's multisig secret keys const std::vector<crypto::key_image> &pkis,
*/ crypto::key_image &ki);
std::vector<crypto::secret_key> calculate_multisig_keys(const std::vector<crypto::public_key>& derivations); } //namespace multisig
crypto::secret_key generate_multisig_view_secret_key(const crypto::secret_key &skey, const std::vector<crypto::secret_key> &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<crypto::public_key> &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<crypto::public_key, cryptonote::subaddress_index>& subaddresses, const crypto::public_key& out_key, const crypto::public_key &tx_public_key, const std::vector<crypto::public_key>& additional_tx_public_keys, size_t real_output_index, const std::vector<crypto::key_image> &pkis, crypto::key_image &ki);
uint32_t multisig_rounds_required(uint32_t participants, uint32_t threshold);
}

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// Copyright (c) 2021, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "multisig_account.h"
#include "crypto/crypto.h"
#include "cryptonote_config.h"
#include "include_base_utils.h"
#include "multisig.h"
#include "multisig_kex_msg.h"
#include "ringct/rctOps.h"
#include "ringct/rctTypes.h"
#include <cstdint>
#include <utility>
#include <vector>
#undef MONERO_DEFAULT_LOG_CATEGORY
#define MONERO_DEFAULT_LOG_CATEGORY "multisig"
namespace multisig
{
//----------------------------------------------------------------------------------------------------------------------
// multisig_account: EXTERNAL
//----------------------------------------------------------------------------------------------------------------------
multisig_account::multisig_account(const crypto::secret_key &base_privkey,
const crypto::secret_key &base_common_privkey) :
m_base_privkey{base_privkey},
m_base_common_privkey{base_common_privkey},
m_multisig_pubkey{rct::rct2pk(rct::identity())},
m_common_pubkey{rct::rct2pk(rct::identity())},
m_kex_rounds_complete{0},
m_next_round_kex_message{multisig_kex_msg{1, base_privkey, std::vector<crypto::public_key>{}, base_common_privkey}.get_msg()}
{
CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(m_base_privkey, m_base_pubkey),
"Failed to derive public key");
}
//----------------------------------------------------------------------------------------------------------------------
// multisig_account: EXTERNAL
//----------------------------------------------------------------------------------------------------------------------
multisig_account::multisig_account(const std::uint32_t threshold,
std::vector<crypto::public_key> signers,
const crypto::secret_key &base_privkey,
const crypto::secret_key &base_common_privkey,
std::vector<crypto::secret_key> multisig_privkeys,
const crypto::secret_key &common_privkey,
const crypto::public_key &multisig_pubkey,
const crypto::public_key &common_pubkey,
const std::uint32_t kex_rounds_complete,
kex_origins_map_t kex_origins_map,
std::string next_round_kex_message) :
m_base_privkey{base_privkey},
m_base_common_privkey{base_common_privkey},
m_multisig_privkeys{std::move(multisig_privkeys)},
m_common_privkey{common_privkey},
m_multisig_pubkey{multisig_pubkey},
m_common_pubkey{common_pubkey},
m_kex_rounds_complete{kex_rounds_complete},
m_kex_keys_to_origins_map{std::move(kex_origins_map)},
m_next_round_kex_message{std::move(next_round_kex_message)}
{
CHECK_AND_ASSERT_THROW_MES(kex_rounds_complete > 0, "multisig account: can't reconstruct account if its kex wasn't initialized");
CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(m_base_privkey, m_base_pubkey),
"Failed to derive public key");
set_multisig_config(threshold, std::move(signers));
}
//----------------------------------------------------------------------------------------------------------------------
// multisig_account: EXTERNAL
//----------------------------------------------------------------------------------------------------------------------
bool multisig_account::account_is_active() const
{
return m_kex_rounds_complete > 0;
}
//----------------------------------------------------------------------------------------------------------------------
// multisig_account: EXTERNAL
//----------------------------------------------------------------------------------------------------------------------
bool multisig_account::multisig_is_ready() const
{
if (account_is_active())
return multisig_kex_rounds_required(m_signers.size(), m_threshold) == m_kex_rounds_complete;
else
return false;
}
//----------------------------------------------------------------------------------------------------------------------
// multisig_account: INTERNAL
//----------------------------------------------------------------------------------------------------------------------
void multisig_account::set_multisig_config(const std::size_t threshold, std::vector<crypto::public_key> signers)
{
// validate
CHECK_AND_ASSERT_THROW_MES(threshold > 0 && threshold <= signers.size(), "multisig account: tried to set invalid threshold.");
CHECK_AND_ASSERT_THROW_MES(signers.size() >= 2 && signers.size() <= config::MULTISIG_MAX_SIGNERS,
"multisig account: tried to set invalid number of signers.");
for (auto signer_it = signers.begin(); signer_it != signers.end(); ++signer_it)
{
// signers should all be unique
CHECK_AND_ASSERT_THROW_MES(std::find(signers.begin(), signer_it, *signer_it) == signer_it,
"multisig account: tried to set signers, but found a duplicate signer unexpectedly.");
// signer pubkeys must be in main subgroup, and not identity
CHECK_AND_ASSERT_THROW_MES(rct::isInMainSubgroup(rct::pk2rct(*signer_it)) && !(*signer_it == rct::rct2pk(rct::identity())),
"multisig account: tried to set signers, but a signer pubkey is invalid.");
}
// own pubkey should be in signers list
CHECK_AND_ASSERT_THROW_MES(std::find(signers.begin(), signers.end(), m_base_pubkey) != signers.end(),
"multisig account: tried to set signers, but did not find the account's base pubkey in signer list.");
// sort signers
std::sort(signers.begin(), signers.end(),
[](const crypto::public_key &key1, const crypto::public_key &key2) -> bool
{
return memcmp(&key1, &key2, sizeof(crypto::public_key)) < 0;
}
);
// set
m_threshold = threshold;
m_signers = std::move(signers);
}
//----------------------------------------------------------------------------------------------------------------------
// multisig_account: EXTERNAL
//----------------------------------------------------------------------------------------------------------------------
void multisig_account::initialize_kex(const std::uint32_t threshold,
std::vector<crypto::public_key> signers,
const std::vector<multisig_kex_msg> &expanded_msgs_rnd1)
{
CHECK_AND_ASSERT_THROW_MES(!account_is_active(), "multisig account: tried to initialize kex, but already initialized");
// only mutate account if update succeeds
multisig_account temp_account{*this};
temp_account.set_multisig_config(threshold, std::move(signers));
temp_account.kex_update_impl(expanded_msgs_rnd1);
*this = std::move(temp_account);
}
//----------------------------------------------------------------------------------------------------------------------
// multisig_account: EXTERNAL
//----------------------------------------------------------------------------------------------------------------------
void multisig_account::kex_update(const std::vector<multisig_kex_msg> &expanded_msgs)
{
CHECK_AND_ASSERT_THROW_MES(account_is_active(), "multisig account: tried to update kex, but kex isn't initialized yet.");
CHECK_AND_ASSERT_THROW_MES(!multisig_is_ready(), "multisig account: tried to update kex, but kex is already complete.");
multisig_account temp_account{*this};
temp_account.kex_update_impl(expanded_msgs);
*this = std::move(temp_account);
}
//----------------------------------------------------------------------------------------------------------------------
// EXTERNAL
//----------------------------------------------------------------------------------------------------------------------
std::uint32_t multisig_kex_rounds_required(const std::uint32_t num_signers, const std::uint32_t threshold)
{
CHECK_AND_ASSERT_THROW_MES(num_signers >= threshold, "num_signers must be >= threshold");
CHECK_AND_ASSERT_THROW_MES(threshold >= 1, "threshold must be >= 1");
return num_signers - threshold + 1;
}
//----------------------------------------------------------------------------------------------------------------------
} //namespace multisig

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// 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 <cstdint>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
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<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>>;
//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<crypto::public_key> signers,
const crypto::secret_key &base_privkey,
const crypto::secret_key &base_common_privkey,
std::vector<crypto::secret_key> multisig_privkeys,
const crypto::secret_key &common_privkey,
const crypto::public_key &multisig_pubkey,
const crypto::public_key &common_pubkey,
const std::uint32_t kex_rounds_complete,
kex_origins_map_t kex_origins_map,
std::string next_round_kex_message);
// 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<crypto::public_key>& 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<crypto::secret_key>& 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<crypto::public_key> 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<crypto::public_key> signers,
const std::vector<multisig_kex_msg> &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<multisig_kex_msg> &expanded_msgs);
private:
// implementation of kex_update() (non-transactional)
void kex_update_impl(const std::vector<multisig_kex_msg> &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<multisig_kex_msg> &expanded_msgs,
const std::uint32_t rounds_required,
std::vector<crypto::public_key> &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<crypto::public_key> 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<crypto::secret_key> 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

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// 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 <boost/math/special_functions/binomial.hpp>
#include <algorithm>
#include <cmath>
#include <cstdint>
#include <limits>
#include <memory>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#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<crypto::secret_key> 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<crypto::public_key> &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<crypto::public_key> final_keys,
std::vector<crypto::secret_key> &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<crypto::public_key, std::size_t> 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<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>> &pubkey_origins_map,
std::unordered_map<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>> &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<crypto::public_key> 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<multisig_kex_msg> &expanded_msgs,
const std::vector<crypto::public_key> &exclude_pubkeys,
std::unordered_map<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>> &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<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>> 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<crypto::public_key> &signers,
const std::vector<multisig_kex_msg> &expanded_msgs,
const std::vector<crypto::public_key> &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<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>> 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<crypto::public_key, std::unordered_set<crypto::public_key>> 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<std::int32_t>::digits <= std::numeric_limits<double>::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<double>(n, k);
if (fp_result < 0)
return 0;
if (fp_result > std::numeric_limits<std::int32_t>::max()) // note: std::round() returns std::int32_t
return 0;
return static_cast<std::uint32_t>(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<crypto::public_key> &signers,
const std::vector<multisig_kex_msg> &expanded_msgs,
const std::vector<crypto::public_key> &exclude_pubkeys,
std::unordered_map<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>> &keys_to_origins_map_out)
{
// evaluate messages
std::unordered_map<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>> 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<multisig_kex_msg> &expanded_msgs,
const std::uint32_t rounds_required,
std::vector<crypto::public_key> &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<crypto::secret_key> 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<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>> 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<crypto::public_key> 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<multisig_kex_msg> &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<crypto::public_key> 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<crypto::public_key_memsafe, std::unordered_set<crypto::public_key>> 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

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@ -0,0 +1,290 @@
// 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 <boost/utility/string_ref.hpp>
#include <sstream>
#include <utility>
#include <vector>
#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<crypto::public_key> 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<char>(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<true> 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.");
binary_archive<false> b_archive{epee::strspan<std::uint8_t>(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

109
src/multisig/multisig_kex_msg.h Normal file
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@ -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 <cstdint>
#include <vector>
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<crypto::public_key> 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<crypto::public_key>& 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<crypto::public_key> 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

78
src/multisig/multisig_kex_msg_serialization.h Normal file
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@ -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 <cstdint>
#include <vector>
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<crypto::public_key> 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

63
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@ -235,7 +235,6 @@ namespace
const char* USAGE_IMPORT_OUTPUTS("import_outputs <filename>"); const char* USAGE_IMPORT_OUTPUTS("import_outputs <filename>");
const char* USAGE_SHOW_TRANSFER("show_transfer <txid>"); const char* USAGE_SHOW_TRANSFER("show_transfer <txid>");
const char* USAGE_MAKE_MULTISIG("make_multisig <threshold> <string1> [<string>...]"); const char* USAGE_MAKE_MULTISIG("make_multisig <threshold> <string1> [<string>...]");
const char* USAGE_FINALIZE_MULTISIG("finalize_multisig <string> [<string>...]");
const char* USAGE_EXCHANGE_MULTISIG_KEYS("exchange_multisig_keys <string> [<string>...]"); const char* USAGE_EXCHANGE_MULTISIG_KEYS("exchange_multisig_keys <string> [<string>...]");
const char* USAGE_EXPORT_MULTISIG_INFO("export_multisig_info <filename>"); const char* USAGE_EXPORT_MULTISIG_INFO("export_multisig_info <filename>");
const char* USAGE_IMPORT_MULTISIG_INFO("import_multisig_info <filename> [<filename>...]"); const char* USAGE_IMPORT_MULTISIG_INFO("import_multisig_info <filename> [<filename>...]");
@ -1021,7 +1020,7 @@ bool simple_wallet::prepare_multisig_main(const std::vector<std::string> &args,
SCOPED_WALLET_UNLOCK_ON_BAD_PASSWORD(return false;); 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() << multisig_info;
success_msg_writer() << tr("Send this multisig info to all other participants, then use make_multisig <threshold> <info1> [<info2>...] with others' multisig info"); success_msg_writer() << tr("Send this multisig info to all other participants, then use make_multisig <threshold> <info1> [<info2>...] 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 "); success_msg_writer() << tr("This includes the PRIVATE view key, so needs to be disclosed only to that multisig wallet's participants ");
@ -1122,58 +1121,6 @@ bool simple_wallet::make_multisig_main(const std::vector<std::string> &args, boo
return true; return true;
} }
bool simple_wallet::finalize_multisig(const std::vector<std::string> &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<std::string> &args) bool simple_wallet::exchange_multisig_keys(const std::vector<std::string> &args)
{ {
exchange_multisig_keys_main(args, false); exchange_multisig_keys_main(args, false);
@ -3627,10 +3574,6 @@ simple_wallet::simple_wallet()
m_cmd_binder.set_handler("make_multisig", boost::bind(&simple_wallet::on_command, this, &simple_wallet::make_multisig, _1), m_cmd_binder.set_handler("make_multisig", boost::bind(&simple_wallet::on_command, this, &simple_wallet::make_multisig, _1),
tr(USAGE_MAKE_MULTISIG), tr(USAGE_MAKE_MULTISIG),
tr("Turn this wallet into a multisig wallet")); 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", m_cmd_binder.set_handler("exchange_multisig_keys",
boost::bind(&simple_wallet::on_command, this, &simple_wallet::exchange_multisig_keys, _1), boost::bind(&simple_wallet::on_command, this, &simple_wallet::exchange_multisig_keys, _1),
tr(USAGE_EXCHANGE_MULTISIG_KEYS), tr(USAGE_EXCHANGE_MULTISIG_KEYS),
@ -10973,8 +10916,8 @@ void simple_wallet::mms_init(const std::vector<std::string> &args)
std::vector<std::string> numbers; std::vector<std::string> numbers;
boost::split(numbers, mn, boost::is_any_of("/")); boost::split(numbers, mn, boost::is_any_of("/"));
bool mn_ok = (numbers.size() == 2) bool mn_ok = (numbers.size() == 2)
&& get_number_from_arg(numbers[1], num_authorized_signers, 2, 100) && get_number_from_arg(numbers[1], num_authorized_signers, 2, config::MULTISIG_MAX_SIGNERS)
&& get_number_from_arg(numbers[0], num_required_signers, 2, num_authorized_signers); && get_number_from_arg(numbers[0], num_required_signers, 1, num_authorized_signers);
if (!mn_ok) if (!mn_ok)
{ {
fail_msg_writer() << tr("Error in the number of required signers and/or authorized signers"); fail_msg_writer() << tr("Error in the number of required signers and/or authorized signers");

1
src/simplewallet/simplewallet.h
View File

@ -233,7 +233,6 @@ namespace cryptonote
bool prepare_multisig_main(const std::vector<std::string>& args, bool called_by_mms); bool prepare_multisig_main(const std::vector<std::string>& args, bool called_by_mms);
bool make_multisig(const std::vector<std::string>& args); bool make_multisig(const std::vector<std::string>& args);
bool make_multisig_main(const std::vector<std::string>& args, bool called_by_mms); bool make_multisig_main(const std::vector<std::string>& args, bool called_by_mms);
bool finalize_multisig(const std::vector<std::string> &args);
bool exchange_multisig_keys(const std::vector<std::string> &args); bool exchange_multisig_keys(const std::vector<std::string> &args);
bool exchange_multisig_keys_main(const std::vector<std::string> &args, bool called_by_mms); bool exchange_multisig_keys_main(const std::vector<std::string> &args, bool called_by_mms);
bool export_multisig(const std::vector<std::string>& args); bool export_multisig(const std::vector<std::string>& args);

24
src/wallet/api/wallet.cpp
View File

@ -1332,7 +1332,7 @@ MultisigState WalletImpl::multisig() const {
string WalletImpl::getMultisigInfo() const { string WalletImpl::getMultisigInfo() const {
try { try {
clearStatus(); clearStatus();
return m_wallet->get_multisig_info(); return m_wallet->get_multisig_first_kex_msg();
} catch (const exception& e) { } catch (const exception& e) {
LOG_ERROR("Error on generating multisig info: " << e.what()); LOG_ERROR("Error on generating multisig info: " << e.what());
setStatusError(string(tr("Failed to get multisig info: ")) + e.what()); setStatusError(string(tr("Failed to get multisig info: ")) + e.what());
@ -1341,7 +1341,7 @@ string WalletImpl::getMultisigInfo() const {
return string(); return string();
} }
string WalletImpl::makeMultisig(const vector<string>& info, uint32_t threshold) { string WalletImpl::makeMultisig(const vector<string>& info, const uint32_t threshold) {
try { try {
clearStatus(); clearStatus();
@ -1366,30 +1366,12 @@ std::string WalletImpl::exchangeMultisigKeys(const std::vector<std::string> &inf
return m_wallet->exchange_multisig_keys(epee::wipeable_string(m_password), info); return m_wallet->exchange_multisig_keys(epee::wipeable_string(m_password), info);
} catch (const exception& e) { } catch (const exception& e) {
LOG_ERROR("Error on exchanging multisig keys: " << e.what()); 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(); return string();
} }
bool WalletImpl::finalizeMultisig(const vector<string>& 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) { bool WalletImpl::exportMultisigImages(string& images) {
try { try {
clearStatus(); clearStatus();

1
src/wallet/api/wallet.h
View File

@ -147,7 +147,6 @@ public:
std::string getMultisigInfo() const override; std::string getMultisigInfo() const override;
std::string makeMultisig(const std::vector<std::string>& info, uint32_t threshold) override; std::string makeMultisig(const std::vector<std::string>& info, uint32_t threshold) override;
std::string exchangeMultisigKeys(const std::vector<std::string> &info) override; std::string exchangeMultisigKeys(const std::vector<std::string> &info) override;
bool finalizeMultisig(const std::vector<std::string>& extraMultisigInfo) override;
bool exportMultisigImages(std::string& images) override; bool exportMultisigImages(std::string& images) override;
size_t importMultisigImages(const std::vector<std::string>& images) override; size_t importMultisigImages(const std::vector<std::string>& images) override;
bool hasMultisigPartialKeyImages() const override; bool hasMultisigPartialKeyImages() const override;

8
src/wallet/api/wallet2_api.h
View File

@ -790,7 +790,7 @@ struct Wallet
/** /**
* @brief makeMultisig - switches wallet in multisig state. The one and only creation phase for N / N wallets * @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 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 * @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<std::string>& info, uint32_t threshold) = 0; virtual std::string makeMultisig(const std::vector<std::string>& 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 * @return new info string if more rounds required or an empty string if wallet creation is done
*/ */
virtual std::string exchangeMultisigKeys(const std::vector<std::string> &info) = 0; virtual std::string exchangeMultisigKeys(const std::vector<std::string> &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<std::string>& extraMultisigInfo) = 0;
/** /**
* @brief exportMultisigImages - exports transfers' key images * @brief exportMultisigImages - exports transfers' key images
* @param images - output paramter for hex encoded array of images * @param images - output paramter for hex encoded array of images

602
src/wallet/wallet2.cpp
View File

@ -28,6 +28,7 @@
// //
// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers // Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
#include <algorithm>
#include <numeric> #include <numeric>
#include <tuple> #include <tuple>
#include <queue> #include <queue>
@ -59,6 +60,8 @@ using namespace epee;
#include "misc_language.h" #include "misc_language.h"
#include "cryptonote_basic/cryptonote_basic_impl.h" #include "cryptonote_basic/cryptonote_basic_impl.h"
#include "multisig/multisig.h" #include "multisig/multisig.h"
#include "multisig/multisig_account.h"
#include "multisig/multisig_kex_msg.h"
#include "common/boost_serialization_helper.h" #include "common/boost_serialization_helper.h"
#include "common/command_line.h" #include "common/command_line.h"
#include "common/threadpool.h" #include "common/threadpool.h"
@ -149,7 +152,6 @@ using namespace cryptonote;
#define RECENT_SPEND_WINDOW (50 * DIFFICULTY_TARGET_V2) #define RECENT_SPEND_WINDOW (50 * DIFFICULTY_TARGET_V2)
static const std::string MULTISIG_SIGNATURE_MAGIC = "SigMultisigPkV1"; 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"; static const std::string ASCII_OUTPUT_MAGIC = "MoneroAsciiDataV1";
@ -167,42 +169,6 @@ namespace
return dir.string(); return dir.string();
} }
std::string pack_multisignature_keys(const std::string& prefix, const std::vector<crypto::public_key>& 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<crypto::public_key> secret_keys_to_public_keys(const std::vector<crypto::secret_key>& keys)
{
std::vector<crypto::public_key> 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<crypto::public_key>& s1, const std::unordered_set<crypto::public_key>& s2) bool keys_intersect(const std::unordered_set<crypto::public_key>& s1, const std::unordered_set<crypto::public_key>& s2)
{ {
if (s1.empty() || s2.empty()) if (s1.empty() || s2.empty())
@ -4768,7 +4734,6 @@ void wallet2::generate(const std::string& wallet_, const epee::wipeable_string&
memwipe(&skey, sizeof(rct::key)); memwipe(&skey, sizeof(rct::key));
m_account.make_multisig(view_secret_key, spend_secret_key, spend_public_key, multisig_keys); 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 // 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 // (because the original keys are not (yet) part of the restore info), so
@ -4983,24 +4948,12 @@ void wallet2::restore(const std::string& wallet_, const epee::wipeable_string& p
store(); store();
} }
} }
//----------------------------------------------------------------------------------------------------
std::string wallet2::make_multisig(const epee::wipeable_string &password, std::string wallet2::make_multisig(const epee::wipeable_string &password,
const std::vector<crypto::secret_key> &view_keys, const std::vector<std::string> &initial_kex_msgs,
const std::vector<crypto::public_key> &spend_keys, const std::uint32_t threshold)
uint32_t threshold)
{ {
CHECK_AND_ASSERT_THROW_MES(!view_keys.empty(), "empty view keys"); // decrypt account 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<crypto::secret_key> 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<crypto::public_key> multisig_signers;
// decrypt keys
epee::misc_utils::auto_scope_leave_caller keys_reencryptor; epee::misc_utils::auto_scope_leave_caller keys_reencryptor;
if (m_ask_password == AskPasswordToDecrypt && !m_unattended && !m_watch_only) if (m_ask_password == AskPasswordToDecrypt && !m_unattended && !m_watch_only)
{ {
@ -5008,104 +4961,89 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
crypto::generate_chacha_key(password.data(), password.size(), chacha_key, m_kdf_rounds); crypto::generate_chacha_key(password.data(), password.size(), chacha_key, m_kdf_rounds);
m_account.encrypt_viewkey(chacha_key); m_account.encrypt_viewkey(chacha_key);
m_account.decrypt_keys(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: // create multisig account
// 1. First round is exchange of view secret keys and public spend keys. multisig::multisig_account multisig_account{
// 2. Middle round is exchange of derivations: Ki = b * Mj, where b - spend secret key, multisig::get_multisig_blinded_secret_key(get_account().get_keys().m_spend_secret_key),
// M - public multisig key (in first round it equals to public spend key), K - new public multisig key. multisig::get_multisig_blinded_secret_key(get_account().get_keys().m_view_secret_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.
// IMPORTANT: wallet's public spend key is not equal to secret_spend_key * G! // open initial kex messages, validate them, extract signers
// Wallet's public spend key is the sum of unique public multisig keys of all participants. std::vector<multisig::multisig_kex_msg> expanded_msgs;
// secret_spend_key * G = public signer key std::vector<crypto::public_key> 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 expanded_msgs.emplace_back(msg);
MINFO("Creating spend key...");
// Calculates all multisig keys and spend key // validate each message
cryptonote::generate_multisig_N_N(get_account().get_keys(), spend_keys, multisig_keys, spend_skey, spend_pkey); // 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. // 2. duplicate signers not allowed
multisig_signers = spend_keys; CHECK_AND_ASSERT_THROW_MES(std::find(signers.begin(), signers.end(), expanded_msgs.back().get_signing_pubkey()) == signers.end(),
multisig_signers.push_back(get_multisig_signer_public_key(get_account().get_keys().m_spend_secret_key)); "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(); // add self to signers
multisig_signers = std::vector<crypto::public_key>(spend_keys.size() + 1, crypto::null_pkey); signers.push_back(multisig_account.get_base_pubkey());
if (threshold == spend_keys.size()) // intialize key exchange
{ multisig_account.initialize_kex(threshold, signers, expanded_msgs);
// N - 1 / N case 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 // update wallet state
// 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;
}
}
if (!m_original_keys_available) 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 // 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) // (making a wallet multisig overwrites those keys, see account_base::make_multisig)
m_original_address = m_account.get_keys().m_account_address; m_original_address = get_account().get_keys().m_account_address;
m_original_view_secret_key = m_account.get_keys().m_view_secret_key; m_original_view_secret_key = get_account().get_keys().m_view_secret_key;
m_original_keys_available = true; m_original_keys_available = true;
} }
clear(); 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..."); 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), CHECK_AND_ASSERT_THROW_MES(m_account.make_multisig(multisig_account.get_common_privkey(),
"Failed to create multisig wallet due to bad keys"); multisig_account.get_base_privkey(),
memwipe(&spend_skey, sizeof(rct::key)); 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); init_type(hw::device::device_type::SOFTWARE);
m_original_keys_available = true; m_original_keys_available = true;
m_multisig = true; m_multisig = true;
m_multisig_threshold = threshold; m_multisig_threshold = threshold;
m_multisig_signers = multisig_signers; m_multisig_signers = signers;
++m_multisig_rounds_passed; 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 // re-encrypt keys
keys_reencryptor = epee::misc_utils::auto_scope_leave_caller(); keys_reencryptor = epee::misc_utils::auto_scope_leave_caller();
@ -5118,42 +5056,18 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
if (!m_wallet_file.empty()) if (!m_wallet_file.empty())
store(); store();
return extra_multisig_info; return multisig_account.get_next_kex_round_msg();
} }
//----------------------------------------------------------------------------------------------------
std::string wallet2::exchange_multisig_keys(const epee::wipeable_string &password, std::string wallet2::exchange_multisig_keys(const epee::wipeable_string &password,
const std::vector<std::string> &info) const std::vector<std::string> &kex_messages)
{ {
THROW_WALLET_EXCEPTION_IF(info.empty(), bool ready{false};
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<crypto::public_key> signers;
std::unordered_set<crypto::public_key> 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<crypto::public_key> derivations,
std::vector<crypto::public_key> signers)
{
CHECK_AND_ASSERT_THROW_MES(!derivations.empty(), "empty pkeys");
CHECK_AND_ASSERT_THROW_MES(!signers.empty(), "empty signers");
bool ready = false;
CHECK_AND_ASSERT_THROW_MES(multisig(&ready), "The wallet is not multisig"); 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(!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; epee::misc_utils::auto_scope_leave_caller keys_reencryptor;
if (m_ask_password == AskPasswordToDecrypt && !m_unattended && !m_watch_only) if (m_ask_password == AskPasswordToDecrypt && !m_unattended && !m_watch_only)
{ {
@ -5161,37 +5075,72 @@ std::string wallet2::exchange_multisig_keys(const epee::wipeable_string &passwor
crypto::generate_chacha_key(password.data(), password.size(), chacha_key, m_kdf_rounds); crypto::generate_chacha_key(password.data(), password.size(), chacha_key, m_kdf_rounds);
m_account.encrypt_viewkey(chacha_key); m_account.encrypt_viewkey(chacha_key);
m_account.decrypt_keys(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<multisig::multisig_kex_msg> 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<crypto::public_key>(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 are encrypted again
keys_reencryptor = epee::misc_utils::auto_scope_leave_caller(); keys_reencryptor = epee::misc_utils::auto_scope_leave_caller();
@ -5213,270 +5162,28 @@ std::string wallet2::exchange_multisig_keys(const epee::wipeable_string &passwor
if (!m_wallet_file.empty()) if (!m_wallet_file.empty())
store(); store();
return {};
} }
// Below are either middle or secret spend key establishment rounds // wallet/file relationship
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<crypto::public_key>(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<crypto::public_key>(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;
if (!m_wallet_file.empty()) if (!m_wallet_file.empty())
create_keys_file(m_wallet_file, false, password, boost::filesystem::exists(m_wallet_file + ".address.txt")); 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<std::string>& info, std::string wallet2::get_multisig_first_kex_msg() const
std::vector<crypto::public_key> &public_keys,
std::vector<crypto::secret_key> &secret_keys) const
{ {
// parse all multisig info // create multisig account
public_keys.resize(info.size()); multisig::multisig_account multisig_account{
secret_keys.resize(info.size()); // k_base = H(normal private spend key)
for (size_t i = 0; i < info.size(); ++i) multisig::get_multisig_blinded_secret_key(get_account().get_keys().m_spend_secret_key),
{ // k_view = H(normal private view key)
THROW_WALLET_EXCEPTION_IF(!verify_multisig_info(info[i], secret_keys[i], public_keys[i]), multisig::get_multisig_blinded_secret_key(get_account().get_keys().m_view_secret_key)
error::wallet_internal_error, "Bad multisig info: " + info[i]); };
}
// remove duplicates return multisig_account.get_next_kex_round_msg();
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");
}
}
} }
//----------------------------------------------------------------------------------------------------
std::string wallet2::make_multisig(const epee::wipeable_string &password,
const std::vector<std::string> &info,
uint32_t threshold)
{
std::vector<crypto::secret_key> secret_keys(info.size());
std::vector<crypto::public_key> 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<crypto::public_key> &pkeys, std::vector<crypto::public_key> 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<std::string>& info,
std::vector<crypto::public_key> &signers,
std::unordered_set<crypto::public_key> &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<std::string> &info)
{
std::unordered_set<crypto::public_key> public_keys;
std::vector<crypto::public_key> 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<crypto::public_key> &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 bool wallet2::multisig(bool *ready, uint32_t *threshold, uint32_t *total) const
{ {
if (!m_multisig) if (!m_multisig)
@ -5489,7 +5196,7 @@ 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())); *ready = !(get_account().get_keys().m_account_address.m_spend_public_key == rct::rct2pk(rct::identity()));
return true; return true;
} }
//----------------------------------------------------------------------------------------------------
bool wallet2::has_multisig_partial_key_images() const bool wallet2::has_multisig_partial_key_images() const
{ {
if (!m_multisig) if (!m_multisig)
@ -5499,7 +5206,7 @@ bool wallet2::has_multisig_partial_key_images() const
return true; return true;
return false; return false;
} }
//----------------------------------------------------------------------------------------------------
bool wallet2::has_unknown_key_images() const bool wallet2::has_unknown_key_images() const
{ {
for (const auto &td: m_transfers) for (const auto &td: m_transfers)
@ -13323,13 +13030,6 @@ size_t wallet2::import_outputs_from_str(const std::string &outputs_st)
return imported_outputs; 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 crypto::public_key wallet2::get_multisig_signer_public_key() const
{ {
CHECK_AND_ASSERT_THROW_MES(m_multisig, "Wallet is not multisig"); CHECK_AND_ASSERT_THROW_MES(m_multisig, "Wallet is not multisig");
@ -13373,7 +13073,7 @@ 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"); CHECK_AND_ASSERT_THROW_MES(n < m_transfers.size(), "Bad m_transfers index");
rct::multisig_kLRki kLRki; rct::multisig_kLRki kLRki;
kLRki.k = k; 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); kLRki.ki = rct::ki2rct(m_transfers[n].m_key_image);
return kLRki; return kLRki;
} }
@ -13420,7 +13120,7 @@ crypto::key_image wallet2::get_multisig_composite_key_image(size_t n) const
for (const auto &info: td.m_multisig_info) for (const auto &info: td.m_multisig_info)
for (const auto &pki: info.m_partial_key_images) for (const auto &pki: info.m_partial_key_images)
pkis.push_back(pki); 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"); THROW_WALLET_EXCEPTION_IF(!r, error::wallet_internal_error, "Failed to generate key image");
return ki; return ki;
} }
@ -13443,7 +13143,7 @@ cryptonote::blobdata wallet2::export_multisig()
for (size_t m = 0; m < get_account().get_multisig_keys().size(); ++m) 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 // 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"); CHECK_AND_ASSERT_THROW_MES(r, "Failed to generate key image");
info[n].m_partial_key_images.push_back(ki); info[n].m_partial_key_images.push_back(ki);
} }

46
src/wallet/wallet2.h
View File

@ -757,45 +757,20 @@ private:
* to other participants * to other participants
*/ */
std::string make_multisig(const epee::wipeable_string &password, std::string make_multisig(const epee::wipeable_string &password,
const std::vector<std::string> &info, const std::vector<std::string> &kex_messages,
uint32_t threshold); 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 * \return empty if done, non empty if we need to send another string
* to other participants * to other participants
*/ */
std::string make_multisig(const epee::wipeable_string &password,
const std::vector<crypto::secret_key> &view_keys,
const std::vector<crypto::public_key> &spend_keys,
uint32_t threshold);
std::string exchange_multisig_keys(const epee::wipeable_string &password, std::string exchange_multisig_keys(const epee::wipeable_string &password,
const std::vector<std::string> &info); const std::vector<std::string> &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::string get_multisig_first_kex_msg() const;
std::unordered_set<crypto::public_key> pkeys,
std::vector<crypto::public_key> signers);
/*!
* \brief Finalizes creation of a multisig wallet
*/
bool finalize_multisig(const epee::wipeable_string &password, const std::vector<std::string> &info);
/*!
* \brief Finalizes creation of a multisig wallet
*/
bool finalize_multisig(const epee::wipeable_string &password, const std::unordered_set<crypto::public_key> &pkeys, std::vector<crypto::public_key> 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<crypto::public_key> &pkeys, crypto::public_key &signer);
/*! /*!
* Export multisig info * Export multisig info
* This will generate and remember new k values * This will generate and remember new k values
@ -1477,7 +1452,6 @@ private:
void set_attribute(const std::string &key, const std::string &value); void set_attribute(const std::string &key, const std::string &value);
bool get_attribute(const std::string &key, std::string &value) const; 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_signer_public_key() const;
crypto::public_key get_multisig_signing_public_key(size_t idx) 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; crypto::public_key get_multisig_signing_public_key(const crypto::secret_key &skey) const;
@ -1641,12 +1615,6 @@ private:
bool get_rct_distribution(uint64_t &start_height, std::vector<uint64_t> &distribution); bool get_rct_distribution(uint64_t &start_height, std::vector<uint64_t> &distribution);
uint64_t get_segregation_fork_height() const; uint64_t get_segregation_fork_height() const;
void unpack_multisig_info(const std::vector<std::string>& info,
std::vector<crypto::public_key> &public_keys,
std::vector<crypto::secret_key> &secret_keys) const;
bool unpack_extra_multisig_info(const std::vector<std::string>& info,
std::vector<crypto::public_key> &signers,
std::unordered_set<crypto::public_key> &pkeys) const;
void cache_tx_data(const cryptonote::transaction& tx, const crypto::hash &txid, tx_cache_data &tx_cache_data) const; void cache_tx_data(const cryptonote::transaction& tx, const crypto::hash &txid, tx_cache_data &tx_cache_data) const;
std::shared_ptr<std::map<std::pair<uint64_t, uint64_t>, size_t>> create_output_tracker_cache() const; std::shared_ptr<std::map<std::pair<uint64_t, uint64_t>, size_t>> create_output_tracker_cache() const;

54
src/wallet/wallet_rpc_server.cpp
View File

@ -3938,7 +3938,7 @@ namespace tools
return false; return false;
} }
res.multisig_info = m_wallet->get_multisig_info(); res.multisig_info = m_wallet->get_multisig_first_kex_msg();
return true; return true;
} }
//------------------------------------------------------------------------------------------------------------------------------ //------------------------------------------------------------------------------------------------------------------------------
@ -4069,7 +4069,7 @@ namespace tools
catch (const std::exception &e) catch (const std::exception &e)
{ {
er.code = WALLET_RPC_ERROR_CODE_UNKNOWN_ERROR; 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; return false;
} }
@ -4094,53 +4094,7 @@ 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) 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); return false;
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;
} }
//------------------------------------------------------------------------------------------------------------------------------ //------------------------------------------------------------------------------------------------------------------------------
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) 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)
@ -4168,7 +4122,7 @@ namespace tools
return false; 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.code = WALLET_RPC_ERROR_CODE_THRESHOLD_NOT_REACHED;
er.message = "Needs multisig info from more participants"; er.message = "Needs multisig info from more participants";

11
src/wallet/wallet_rpc_server_commands_defs.h
View File

@ -47,7 +47,7 @@
// advance which version they will stop working with // advance which version they will stop working with
// Don't go over 32767 for any of these // Don't go over 32767 for any of these
#define WALLET_RPC_VERSION_MAJOR 1 #define WALLET_RPC_VERSION_MAJOR 1
#define WALLET_RPC_VERSION_MINOR 23 #define WALLET_RPC_VERSION_MINOR 24
#define MAKE_WALLET_RPC_VERSION(major,minor) (((major)<<16)|(minor)) #define MAKE_WALLET_RPC_VERSION(major,minor) (((major)<<16)|(minor))
#define WALLET_RPC_VERSION MAKE_WALLET_RPC_VERSION(WALLET_RPC_VERSION_MAJOR, WALLET_RPC_VERSION_MINOR) #define WALLET_RPC_VERSION MAKE_WALLET_RPC_VERSION(WALLET_RPC_VERSION_MAJOR, WALLET_RPC_VERSION_MINOR)
namespace tools namespace tools
@ -2504,24 +2504,17 @@ namespace wallet_rpc
struct COMMAND_RPC_FINALIZE_MULTISIG struct COMMAND_RPC_FINALIZE_MULTISIG
{ {
// NOP
struct request_t struct request_t
{ {
std::string password;
std::vector<std::string> multisig_info;
BEGIN_KV_SERIALIZE_MAP() BEGIN_KV_SERIALIZE_MAP()
KV_SERIALIZE(password)
KV_SERIALIZE(multisig_info)
END_KV_SERIALIZE_MAP() END_KV_SERIALIZE_MAP()
}; };
typedef epee::misc_utils::struct_init<request_t> request; typedef epee::misc_utils::struct_init<request_t> request;
struct response_t struct response_t
{ {
std::string address;
BEGIN_KV_SERIALIZE_MAP() BEGIN_KV_SERIALIZE_MAP()
KV_SERIALIZE(address)
END_KV_SERIALIZE_MAP() END_KV_SERIALIZE_MAP()
}; };
typedef epee::misc_utils::struct_init<response_t> response; typedef epee::misc_utils::struct_init<response_t> response;

2
tests/core_tests/chaingen.h
View File

@ -836,7 +836,7 @@ inline bool do_replay_file(const std::string& filename)
{ \ { \
for (size_t msidx = 0; msidx < total; ++msidx) \ for (size_t msidx = 0; msidx < total; ++msidx) \
account[msidx].generate(); \ 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) } while(0)
#define MAKE_ACCOUNT(VEC_EVENTS, account) \ #define MAKE_ACCOUNT(VEC_EVENTS, account) \

132
tests/core_tests/multisig.cpp
View File

@ -28,98 +28,88 @@
// //
// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers // 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 "chaingen.h"
#include "multisig.h" #include "multisig.h"
#include "common/apply_permutation.h"
#include "crypto/crypto.h"
#include "cryptonote_basic/cryptonote_basic.h"
#include "device/device.hpp" #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 epee;
using namespace crypto; using namespace crypto;
using namespace cryptonote; using namespace cryptonote;
using namespace multisig;
//#define NO_MULTISIG //#define NO_MULTISIG
void make_multisig_accounts(std::vector<cryptonote::account_base>& account, uint32_t threshold) static bool make_multisig_accounts(std::vector<cryptonote::account_base> &accounts, const uint32_t threshold)
{ {
std::vector<crypto::secret_key> all_view_keys; CHECK_AND_ASSERT_MES(accounts.size() > 0, false, "Invalid multisig scheme");
std::vector<std::vector<crypto::public_key>> derivations(account.size());
//storage for all set of multisig derivations and spend public key (in first round)
std::unordered_set<crypto::public_key> exchanging_keys;
for (size_t msidx = 0; msidx < account.size(); ++msidx) std::vector<multisig_account> multisig_accounts;
std::vector<crypto::public_key> signers;
std::vector<multisig_kex_msg> 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); // create account and collect signer
all_view_keys.push_back(vkh); 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); signers.emplace_back(multisig_accounts.back().get_base_pubkey());
crypto::public_key pskh;
crypto::secret_key_to_public_key(skh, pskh);
derivations[msidx].push_back(pskh); // collect account's first kex msg
exchanging_keys.insert(pskh); round_msgs.emplace_back(multisig_accounts.back().get_next_kex_round_msg());
} }
uint32_t roundsTotal = 1; // initialize accounts and collect kex messages for the next round
if (threshold < account.size()) std::vector<multisig_kex_msg> temp_round_msgs(multisig_accounts.size());
roundsTotal = account.size() - threshold; for (std::size_t account_index{0}; account_index < accounts.size(); ++account_index)
//secret multisig keys of every account
std::vector<std::vector<crypto::secret_key>> multisig_keys(account.size());
std::vector<crypto::secret_key> spend_skey(account.size());
std::vector<crypto::public_key> spend_pkey(account.size());
for (uint32_t round = 0; round < roundsTotal; ++round)
{ {
std::unordered_set<crypto::public_key> roundKeys; multisig_accounts[account_index].initialize_kex(threshold, signers, round_msgs);
for (size_t msidx = 0; msidx < account.size(); ++msidx)
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 multisig_accounts[account_index].kex_update(round_msgs);
auto myKeys = exchanging_keys;
for (const auto& d: derivations[msidx])
myKeys.erase(d);
if (threshold == account.size()) if (!multisig_accounts[account_index].multisig_is_ready())
{ temp_round_msgs[account_index] = multisig_accounts[account_index].get_next_kex_round_msg();
cryptonote::generate_multisig_N_N(account[msidx].get_keys(), std::vector<crypto::public_key>(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<crypto::public_key>(myKeys.begin(), myKeys.end()));
roundKeys.insert(derivations[msidx].begin(), derivations[msidx].end());
}
} }
exchanging_keys = roundKeys;
roundKeys.clear();
} }
std::unordered_set<crypto::public_key> all_multisig_keys; // update accounts post key exchange
for (size_t msidx = 0; msidx < account.size(); ++msidx) for (std::size_t account_index{0}; account_index < accounts.size(); ++account_index)
{ {
std::unordered_set<crypto::secret_key> view_keys(all_view_keys.begin(), all_view_keys.end()); accounts[account_index].make_multisig(multisig_accounts[account_index].get_common_privkey(),
view_keys.erase(all_view_keys[msidx]); multisig_accounts[account_index].get_base_privkey(),
multisig_accounts[account_index].get_multisig_pubkey(),
crypto::secret_key view_skey = cryptonote::generate_multisig_view_secret_key(account[msidx].get_keys().m_view_secret_key, std::vector<secret_key>(view_keys.begin(), view_keys.end())); multisig_accounts[account_index].get_multisig_privkeys());
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))));
}
} }
if (threshold < account.size()) return true;
{
std::vector<crypto::public_key> public_keys(std::vector<crypto::public_key>(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);
}
} }
//---------------------------------------------------------------------------------------------------------------------- //----------------------------------------------------------------------------------------------------------------------
@ -238,13 +228,13 @@ bool gen_multisig_tx_validation_base::generate_with(std::vector<test_event_entry
for (size_t n = 0; n < nlr; ++n) for (size_t n = 0; n < nlr; ++n)
{ {
account_k[msidx][tdidx].push_back(rct::rct2sk(rct::skGen())); account_k[msidx][tdidx].push_back(rct::rct2sk(rct::skGen()));
cryptonote::generate_multisig_LR(output_pub_key[tdidx], account_k[msidx][tdidx][n], account_L[msidx][tdidx][n], account_R[msidx][tdidx][n]); multisig::generate_multisig_LR(output_pub_key[tdidx], account_k[msidx][tdidx][n], account_L[msidx][tdidx][n], account_R[msidx][tdidx][n]);
} }
size_t numki = miner_account[msidx].get_multisig_keys().size(); size_t numki = miner_account[msidx].get_multisig_keys().size();
account_ki[msidx][tdidx].resize(numki); account_ki[msidx][tdidx].resize(numki);
for (size_t kiidx = 0; kiidx < numki; ++kiidx) for (size_t kiidx = 0; kiidx < numki; ++kiidx)
{ {
r = cryptonote::generate_multisig_key_image(miner_account[msidx].get_keys(), kiidx, output_pub_key[tdidx], account_ki[msidx][tdidx][kiidx]); r = multisig::generate_multisig_key_image(miner_account[msidx].get_keys(), kiidx, output_pub_key[tdidx], account_ki[msidx][tdidx][kiidx]);
CHECK_AND_ASSERT_MES(r, false, "Failed to generate multisig export key image"); CHECK_AND_ASSERT_MES(r, false, "Failed to generate multisig export key image");
} }
MDEBUG("Party " << msidx << ":"); MDEBUG("Party " << msidx << ":");
@ -303,7 +293,7 @@ bool gen_multisig_tx_validation_base::generate_with(std::vector<test_event_entry
for (size_t msidx = 0; msidx < total; ++msidx) for (size_t msidx = 0; msidx < total; ++msidx)
for (size_t n = 0; n < account_ki[msidx][tdidx].size(); ++n) for (size_t n = 0; n < account_ki[msidx][tdidx].size(); ++n)
pkis.push_back(account_ki[msidx][tdidx][n]); pkis.push_back(account_ki[msidx][tdidx][n]);
r = cryptonote::generate_multisig_composite_key_image(miner_account[0].get_keys(), subaddresses, output_pub_key[tdidx], tx_pub_key[tdidx], additional_tx_keys, 0, pkis, (crypto::key_image&)kLRki.ki); r = multisig::generate_multisig_composite_key_image(miner_account[0].get_keys(), subaddresses, output_pub_key[tdidx], tx_pub_key[tdidx], additional_tx_keys, 0, pkis, (crypto::key_image&)kLRki.ki);
CHECK_AND_ASSERT_MES(r, false, "Failed to generate composite key image"); CHECK_AND_ASSERT_MES(r, false, "Failed to generate composite key image");
MDEBUG("composite ki: " << kLRki.ki); MDEBUG("composite ki: " << kLRki.ki);
MDEBUG("L: " << kLRki.L); MDEBUG("L: " << kLRki.L);
@ -311,7 +301,7 @@ bool gen_multisig_tx_validation_base::generate_with(std::vector<test_event_entry
for (size_t n = 1; n < total; ++n) for (size_t n = 1; n < total; ++n)
{ {
rct::key ki; rct::key ki;
r = cryptonote::generate_multisig_composite_key_image(miner_account[n].get_keys(), subaddresses, output_pub_key[tdidx], tx_pub_key[tdidx], additional_tx_keys, 0, pkis, (crypto::key_image&)ki); r = multisig::generate_multisig_composite_key_image(miner_account[n].get_keys(), subaddresses, output_pub_key[tdidx], tx_pub_key[tdidx], additional_tx_keys, 0, pkis, (crypto::key_image&)ki);
CHECK_AND_ASSERT_MES(r, false, "Failed to generate composite key image"); CHECK_AND_ASSERT_MES(r, false, "Failed to generate composite key image");
CHECK_AND_ASSERT_MES(kLRki.ki == ki, false, "Composite key images do not match"); CHECK_AND_ASSERT_MES(kLRki.ki == ki, false, "Composite key images do not match");
} }

29
tests/functional_tests/multisig.py
View File

@ -39,40 +39,40 @@ from framework.wallet import Wallet
class MultisigTest(): class MultisigTest():
def run_test(self): def run_test(self):
self.reset() self.reset()
self.mine('493DsrfJPqiN3Suv9RcRDoZEbQtKZX1sNcGPA3GhkKYEEmivk8kjQrTdRdVc4ZbmzWJuE157z9NNUKmF2VDfdYDR3CziGMk', 5) self.mine('45J58b7PmKJFSiNPFFrTdtfMcFGnruP7V4CMuRpX7NsH4j3jGHKAjo3YJP2RePX6HMaSkbvTbrWUFhDNcNcHgtNmQ3gr7sG', 5)
self.mine('42jSRGmmKN96V2j3B8X2DbiNThBXW1tSi1rW1uwkqbyURenq3eC3yosNm8HEMdHuWwKMFGzMUB3RCTvcTaW9kHpdRPP7p5y', 5) self.mine('44G2TQNfsiURKkvxp7gbgaJY8WynZvANnhmyMAwv6WeEbAvyAWMfKXRhh3uBXT2UAKhAsUJ7Fg5zjjF2U1iGciFk5duN94i', 5)
self.mine('47fF32AdrmXG84FcPY697uZdd42pMMGiH5UpiTRTt3YX2pZC7t7wkzEMStEicxbQGRfrYvAAYxH6Fe8rnD56EaNwUgxRd53', 5) self.mine('41mro238grj56GnrWkakAKTkBy2yDcXYsUZ2iXCM9pe5Ueajd2RRc6Fhh3uBXT2UAKhAsUJ7Fg5zjjF2U1iGciFk5ief4ZP', 5)
self.mine('44SKxxLQw929wRF6BA9paQ1EWFshNnKhXM3qz6Mo3JGDE2YG3xyzVutMStEicxbQGRfrYvAAYxH6Fe8rnD56EaNwUiqhcwR', 5) self.mine('44vZSprQKJQRFe6t1VHgU4ESvq2dv7TjBLVGE7QscKxMdFSiyyPCEV64NnKUQssFPyWxc2meyt7j63F2S2qtCTRL6dakeff', 5)
self.mine('4ADHswEU3XBUee8pudBkZQd9beJainqNo1BQKkHJujAEPJyQrLj9U4dNm8HEMdHuWwKMFGzMUB3RCTvcTaW9kHpdRUDxgjW', 5) self.mine('47puypSwsV1gvUDratmX4y58fSwikXVehEiBhVLxJA1gRCxHyrRgTDr4NnKUQssFPyWxc2meyt7j63F2S2qtCTRL6aRPj5U', 5)
self.mine('42ey1afDFnn4886T7196doS9GPMzexD9gXpsZJDwVjeRVdFCSoHnv7KPbBeGpzJBzHRCAs9UxqeoyFQMYbqSWYTfJJQAWDm', 60) self.mine('42ey1afDFnn4886T7196doS9GPMzexD9gXpsZJDwVjeRVdFCSoHnv7KPbBeGpzJBzHRCAs9UxqeoyFQMYbqSWYTfJJQAWDm', 60)
self.test_states() self.test_states()
self.create_multisig_wallets(2, 2, '493DsrfJPqiN3Suv9RcRDoZEbQtKZX1sNcGPA3GhkKYEEmivk8kjQrTdRdVc4ZbmzWJuE157z9NNUKmF2VDfdYDR3CziGMk') self.create_multisig_wallets(2, 2, '45J58b7PmKJFSiNPFFrTdtfMcFGnruP7V4CMuRpX7NsH4j3jGHKAjo3YJP2RePX6HMaSkbvTbrWUFhDNcNcHgtNmQ3gr7sG')
self.import_multisig_info([1, 0], 5) self.import_multisig_info([1, 0], 5)
txid = self.transfer([1, 0]) txid = self.transfer([1, 0])
self.import_multisig_info([0, 1], 6) self.import_multisig_info([0, 1], 6)
self.check_transaction(txid) self.check_transaction(txid)
self.create_multisig_wallets(2, 3, '42jSRGmmKN96V2j3B8X2DbiNThBXW1tSi1rW1uwkqbyURenq3eC3yosNm8HEMdHuWwKMFGzMUB3RCTvcTaW9kHpdRPP7p5y') self.create_multisig_wallets(2, 3, '44G2TQNfsiURKkvxp7gbgaJY8WynZvANnhmyMAwv6WeEbAvyAWMfKXRhh3uBXT2UAKhAsUJ7Fg5zjjF2U1iGciFk5duN94i')
self.import_multisig_info([0, 2], 5) self.import_multisig_info([0, 2], 5)
txid = self.transfer([0, 2]) txid = self.transfer([0, 2])
self.import_multisig_info([0, 1, 2], 6) self.import_multisig_info([0, 1, 2], 6)
self.check_transaction(txid) self.check_transaction(txid)
self.create_multisig_wallets(3, 3, '4ADHswEU3XBUee8pudBkZQd9beJainqNo1BQKkHJujAEPJyQrLj9U4dNm8HEMdHuWwKMFGzMUB3RCTvcTaW9kHpdRUDxgjW') self.create_multisig_wallets(3, 3, '41mro238grj56GnrWkakAKTkBy2yDcXYsUZ2iXCM9pe5Ueajd2RRc6Fhh3uBXT2UAKhAsUJ7Fg5zjjF2U1iGciFk5ief4ZP')
self.import_multisig_info([2, 0, 1], 5) self.import_multisig_info([2, 0, 1], 5)
txid = self.transfer([2, 1, 0]) txid = self.transfer([2, 1, 0])
self.import_multisig_info([0, 2, 1], 6) self.import_multisig_info([0, 2, 1], 6)
self.check_transaction(txid) self.check_transaction(txid)
self.create_multisig_wallets(3, 4, '47fF32AdrmXG84FcPY697uZdd42pMMGiH5UpiTRTt3YX2pZC7t7wkzEMStEicxbQGRfrYvAAYxH6Fe8rnD56EaNwUgxRd53') self.create_multisig_wallets(3, 4, '44vZSprQKJQRFe6t1VHgU4ESvq2dv7TjBLVGE7QscKxMdFSiyyPCEV64NnKUQssFPyWxc2meyt7j63F2S2qtCTRL6dakeff')
self.import_multisig_info([0, 2, 3], 5) self.import_multisig_info([0, 2, 3], 5)
txid = self.transfer([0, 2, 3]) txid = self.transfer([0, 2, 3])
self.import_multisig_info([0, 1, 2, 3], 6) self.import_multisig_info([0, 1, 2, 3], 6)
self.check_transaction(txid) self.check_transaction(txid)
self.create_multisig_wallets(2, 4, '44SKxxLQw929wRF6BA9paQ1EWFshNnKhXM3qz6Mo3JGDE2YG3xyzVutMStEicxbQGRfrYvAAYxH6Fe8rnD56EaNwUiqhcwR') self.create_multisig_wallets(2, 4, '47puypSwsV1gvUDratmX4y58fSwikXVehEiBhVLxJA1gRCxHyrRgTDr4NnKUQssFPyWxc2meyt7j63F2S2qtCTRL6aRPj5U')
self.import_multisig_info([1, 2], 5) self.import_multisig_info([1, 2], 5)
txid = self.transfer([1, 2]) txid = self.transfer([1, 2])
self.import_multisig_info([0, 1, 2, 3], 6) self.import_multisig_info([0, 1, 2, 3], 6)
@ -176,10 +176,6 @@ class MultisigTest():
info.append(res.multisig_info) info.append(res.multisig_info)
for i in range(3): for i in range(3):
ok = False
try: res = wallet[i].finalize_multisig(info)
except: ok = True
assert ok
ok = False ok = False
try: res = wallet[i].exchange_multisig_keys(info) try: res = wallet[i].exchange_multisig_keys(info)
except: ok = True except: ok = True
@ -192,11 +188,6 @@ class MultisigTest():
assert res.multisig assert res.multisig
assert res.ready assert res.ready
ok = False
try: res = wallet[0].finalize_multisig(info)
except: ok = True
assert ok
ok = False ok = False
try: res = wallet[0].prepare_multisig() try: res = wallet[0].prepare_multisig()
except: ok = True except: ok = True

232
tests/unit_tests/multisig.cpp
View File

@ -26,12 +26,16 @@
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF // 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. // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "crypto/crypto.h"
#include "multisig/multisig_account.h"
#include "multisig/multisig_kex_msg.h"
#include "ringct/rctOps.h"
#include "wallet/wallet2.h"
#include "gtest/gtest.h" #include "gtest/gtest.h"
#include <cstdint> #include <cstdint>
#include "wallet/wallet2.h"
static const struct static const struct
{ {
const char *address; const char *address;
@ -86,59 +90,145 @@ static void make_wallet(unsigned int idx, tools::wallet2 &wallet)
} }
} }
static std::vector<std::string> exchange_round(std::vector<tools::wallet2>& wallets, const std::vector<std::string>& mis) static std::vector<std::string> exchange_round(std::vector<tools::wallet2>& wallets, const std::vector<std::string>& infos)
{ {
std::vector<std::string> new_infos; std::vector<std::string> new_infos;
for (size_t i = 0; i < wallets.size(); ++i) { new_infos.reserve(infos.size());
new_infos.push_back(wallets[i].exchange_multisig_keys("", mis));
for (size_t i = 0; i < wallets.size(); ++i)
{
new_infos.push_back(wallets[i].exchange_multisig_keys("", infos));
} }
return new_infos; return new_infos;
} }
static void check_results(const std::vector<std::string> &intermediate_infos,
std::vector<tools::wallet2>& wallets,
std::uint32_t M)
{
// check results
std::unordered_set<crypto::secret_key> 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<tools::wallet2>& wallets, unsigned int M) static void make_wallets(std::vector<tools::wallet2>& wallets, unsigned int M)
{ {
ASSERT_TRUE(wallets.size() > 1 && wallets.size() <= KEYS_COUNT); ASSERT_TRUE(wallets.size() > 1 && wallets.size() <= KEYS_COUNT);
ASSERT_TRUE(M <= wallets.size()); 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<std::string> mis(wallets.size()); // initialize wallets, get first round multisig kex msgs
std::vector<std::string> 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]); make_wallet(i, wallets[i]);
wallets[i].decrypt_keys(""); 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(""); wallets[i].encrypt_keys("");
} }
for (auto& wallet: wallets) { // wallets should not be multisig yet
for (const auto &wallet: wallets)
{
ASSERT_FALSE(wallet.multisig()); ASSERT_FALSE(wallet.multisig());
} }
std::vector<std::string> mxis; // make wallets multisig, get second round kex messages (if appropriate)
for (size_t i = 0; i < wallets.size(); ++i) { std::vector<std::string> intermediate_infos(wallets.size());
// 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)); for (size_t i = 0; i < wallets.size(); ++i)
{
intermediate_infos[i] = wallets[i].make_multisig("", initial_infos, M);
} }
while (!mxis[0].empty()) { ++rounds_complete;
mxis = exchange_round(wallets, mxis);
// 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) { EXPECT_EQ(rounds_required, rounds_complete);
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());
if (i != 0) { check_results(intermediate_infos, wallets, M);
// "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));
} TEST(multisig, make_1_2)
} {
std::vector<tools::wallet2> wallets(2);
make_wallets(wallets, 1);
}
TEST(multisig, make_1_3)
{
std::vector<tools::wallet2> wallets(3);
make_wallets(wallets, 1);
} }
TEST(multisig, make_2_2) TEST(multisig, make_2_2)
@ -165,8 +255,88 @@ TEST(multisig, make_2_4)
make_wallets(wallets, 2); make_wallets(wallets, 2);
} }
TEST(multisig, make_2_5) TEST(multisig, multisig_kex_msg)
{ {
std::vector<tools::wallet2> wallets(5); using namespace multisig;
make_wallets(wallets, 2);
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::public_key>{}, crypto::null_skey}));
EXPECT_ANY_THROW((multisig_kex_msg{1, crypto::null_skey, std::vector<crypto::public_key>{}, crypto::null_skey}));
EXPECT_ANY_THROW((multisig_kex_msg{1, signing_skey, std::vector<crypto::public_key>{}, crypto::null_skey}));
EXPECT_ANY_THROW((multisig_kex_msg{1, crypto::null_skey, std::vector<crypto::public_key>{}, 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<crypto::public_key>{}, ancillary_skey}.get_msg()
}));
EXPECT_NO_THROW((multisig_kex_msg{
multisig_kex_msg{1, signing_skey, std::vector<crypto::public_key>{pubkey1}, ancillary_skey}.get_msg()
}));
// round 2
EXPECT_NO_THROW((multisig_kex_msg{
multisig_kex_msg{2, signing_skey, std::vector<crypto::public_key>{pubkey1}, ancillary_skey}.get_msg()
}));
EXPECT_NO_THROW((multisig_kex_msg{
multisig_kex_msg{2, signing_skey, std::vector<crypto::public_key>{pubkey1}, crypto::null_skey}.get_msg()
}));
EXPECT_NO_THROW((multisig_kex_msg{
multisig_kex_msg{2, signing_skey, std::vector<crypto::public_key>{pubkey1, pubkey2}, ancillary_skey}.get_msg()
}));
EXPECT_NO_THROW((multisig_kex_msg{
multisig_kex_msg{2, signing_skey, std::vector<crypto::public_key>{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<crypto::public_key>{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<crypto::public_key>{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());
} }

6
utils/python-rpc/framework/wallet.py
View File

@ -512,14 +512,12 @@ class Wallet(object):
} }
return self.rpc.send_json_rpc_request(make_multisig) return self.rpc.send_json_rpc_request(make_multisig)
def finalize_multisig(self, multisig_info, password = ''): def finalize_multisig(self):
finalize_multisig = { finalize_multisig = {
'method': 'finalize_multisig', 'method': 'finalize_multisig',
'params' : { 'params' : {
'multisig_info': multisig_info,
'password': password,
}, },
'jsonrpc': '2.0', 'jsonrpc': '2.0',
'id': '0' 'id': '0'
} }
return self.rpc.send_json_rpc_request(finalize_multisig) return self.rpc.send_json_rpc_request(finalize_multisig)