monero/src/multisig/multisig.cpp
stoffu 27a196b126
device: untangle cyclic depenency
When #3303 was merged, a cyclic dependency chain was generated:

    libdevice <- libcncrypto <- libringct <- libdevice

This was because libdevice needs access to a set of basic crypto operations
implemented in libringct such as scalarmultBase(), while libringct also needs
access to abstracted crypto operations implemented in libdevice such as
ecdhEncode(). To untangle this cyclic dependency chain, this patch splits libringct
into libringct_basic and libringct, where the basic crypto ops previously in
libringct are moved into libringct_basic. The cyclic dependency is now resolved
thanks to this separation:

    libcncrypto <- libringct_basic <- libdevice <- libcryptonote_basic <- libringct

This eliminates the need for crypto_device.cpp and rctOps_device.cpp.

Also, many abstracted interfaces of hw::device such as encrypt_payment_id() and
get_subaddress_secret_key() were previously implemented in libcryptonote_basic
(cryptonote_format_utils.cpp) and were then called from hw::core::device_default,
which is odd because libdevice is supposed to be independent of libcryptonote_basic.
Therefore, those functions were moved to device_default.cpp.
2018-03-14 21:00:15 +09:00

141 lines
6.8 KiB
C++

// Copyright (c) 2017-2018, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <unordered_set>
#include "include_base_utils.h"
#include "crypto/crypto.h"
#include "ringct/rctOps.h"
#include "cryptonote_basic/account.h"
#include "cryptonote_basic/cryptonote_format_utils.h"
#include "multisig.h"
#undef MONERO_DEFAULT_LOG_CATEGORY
#define MONERO_DEFAULT_LOG_CATEGORY "multisig"
using namespace std;
static const rct::key multisig_salt = { {'M', 'u', 'l', 't' , 'i', 's', 'i', 'g', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 } };
namespace cryptonote
{
//-----------------------------------------------------------------
crypto::secret_key get_multisig_blinded_secret_key(const crypto::secret_key &key)
{
rct::keyV data;
data.push_back(rct::sk2rct(key));
data.push_back(multisig_salt);
return rct::rct2sk(rct::hash_to_scalar(data));
}
//-----------------------------------------------------------------
void generate_multisig_N_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey)
{
// the multisig spend public key is the sum of all spend public keys
multisig_keys.clear();
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));
multisig_keys.push_back(msk);
sc_add(spend_skey.bytes, spend_skey.bytes, (const unsigned char*)msk.data);
}
}
//-----------------------------------------------------------------
crypto::secret_key generate_multisig_view_secret_key(const crypto::secret_key &skey, const std::vector<crypto::secret_key> &skeys)
{
rct::key view_skey = rct::sk2rct(get_multisig_blinded_secret_key(skey));
for (const auto &k: skeys)
sc_add(view_skey.bytes, view_skey.bytes, rct::sk2rct(k).bytes);
return rct::rct2sk(view_skey);
}
//-----------------------------------------------------------------
crypto::public_key generate_multisig_N1_N_spend_public_key(const std::vector<crypto::public_key> &pkeys)
{
rct::key spend_public_key = rct::identity();
for (const auto &pk: pkeys)
{
rct::addKeys(spend_public_key, spend_public_key, rct::pk2rct(pk));
}
return rct::rct2pk(spend_public_key);
}
//-----------------------------------------------------------------
bool generate_multisig_key_image(const account_keys &keys, size_t multisig_key_index, const crypto::public_key& out_key, crypto::key_image& ki)
{
if (multisig_key_index >= keys.m_multisig_keys.size())
return false;
crypto::generate_key_image(out_key, keys.m_multisig_keys[multisig_key_index], ki);
return true;
}
//-----------------------------------------------------------------
void generate_multisig_LR(const crypto::public_key pkey, const crypto::secret_key &k, crypto::public_key &L, crypto::public_key &R)
{
rct::scalarmultBase((rct::key&)L, rct::sk2rct(k));
crypto::generate_key_image(pkey, k, (crypto::key_image&)R);
}
//-----------------------------------------------------------------
bool generate_multisig_composite_key_image(const account_keys &keys, const std::unordered_map<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)
{
cryptonote::keypair in_ephemeral;
if (!cryptonote::generate_key_image_helper(keys, subaddresses, out_key, tx_public_key, additional_tx_public_keys, real_output_index, in_ephemeral, ki, keys.get_device()))
return false;
std::unordered_set<crypto::key_image> used;
for (size_t m = 0; m < keys.m_multisig_keys.size(); ++m)
{
crypto::key_image pki;
bool r = cryptonote::generate_multisig_key_image(keys, m, out_key, pki);
if (!r)
return false;
used.insert(pki);
}
for (const auto &pki: pkis)
{
if (used.find(pki) == used.end())
{
used.insert(pki);
rct::addKeys((rct::key&)ki, rct::ki2rct(ki), rct::ki2rct(pki));
}
}
return true;
}
//-----------------------------------------------------------------
}