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Diffstat (limited to 'src/multisig/multisig.cpp')
| -rw-r--r-- | src/multisig/multisig.cpp | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/src/multisig/multisig.cpp b/src/multisig/multisig.cpp new file mode 100644 index 000000000..39d0e1c4b --- /dev/null +++ b/src/multisig/multisig.cpp @@ -0,0 +1,141 @@ +// Copyright (c) 2017, The Monero Project +// +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without modification, are +// permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this list of +// conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, this list +// of conditions and the following disclaimer in the documentation and/or other +// materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its contributors may be +// used to endorse or promote products derived from this software without specific +// prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY +// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL +// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF +// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include <unordered_set> +#include "include_base_utils.h" +#include "crypto/crypto.h" +#include "ringct/rctOps.h" +#include "cryptonote_basic/account.h" +#include "cryptonote_basic/cryptonote_format_utils.h" +#include "multisig.h" + +#undef MONERO_DEFAULT_LOG_CATEGORY +#define MONERO_DEFAULT_LOG_CATEGORY "multisig" + +using namespace std; + +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)) + 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; + } + //----------------------------------------------------------------- +} |