1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
// Copyright (c) 2017-2023, 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 "crypto/crypto.h"
#include "cryptonote_basic/account.h"
#include "cryptonote_basic/cryptonote_format_utils.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
#define MONERO_DEFAULT_LOG_CATEGORY "multisig"
namespace multisig
{
//----------------------------------------------------------------------------------------------------------------------
crypto::secret_key get_multisig_blinded_secret_key(const crypto::secret_key &key)
{
CHECK_AND_ASSERT_THROW_MES(key != crypto::null_skey, "Unexpected null secret key (danger!).");
rct::key multisig_salt;
static_assert(sizeof(rct::key) == sizeof(config::HASH_KEY_MULTISIG), "Hash domain separator is an unexpected size");
memcpy(multisig_salt.bytes, config::HASH_KEY_MULTISIG, sizeof(rct::key));
// private key = H(key, domain-sep)
rct::keyV data;
data.reserve(2);
data.push_back(rct::sk2rct(key));
data.push_back(multisig_salt);
crypto::secret_key result = rct::rct2sk(rct::hash_to_scalar(data));
memwipe(&data[0], sizeof(rct::key));
return result;
}
//----------------------------------------------------------------------------------------------------------------------
bool generate_multisig_key_image(const cryptonote::account_keys &keys,
std::size_t multisig_key_index,
const crypto::public_key& out_key,
crypto::key_image& ki)
{
if (multisig_key_index >= keys.m_multisig_keys.size())
return false;
crypto::generate_key_image(out_key, keys.m_multisig_keys[multisig_key_index], ki);
return true;
}
//----------------------------------------------------------------------------------------------------------------------
void generate_multisig_LR(const crypto::public_key pkey,
const crypto::secret_key &k,
crypto::public_key &L,
crypto::public_key &R)
{
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 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;
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;
// 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;
// pki = keys.m_multisig_keys[m] * Hp(out_key)
// pki = key image component
// out_key = one-time address of an output owned by the multisig group
bool r = generate_multisig_key_image(keys, m, out_key, pki);
if (!r)
return false;
// this KI component is 'used' because it was included in the partial key image 'ki' above
used.insert(pki);
}
// add the KI components from other participants to the partial KI
// if they not included yet
for (const auto &pki: pkis)
{
if (used.find(pki) == used.end())
{
// ignore components that have already been 'used'
used.insert(pki);
// KI_partial = KI_partial + KI_component[...]
rct::addKeys((rct::key&)ki, rct::ki2rct(ki), rct::ki2rct(pki));
}
}
// at the end, 'ki' will hold the true key image for our output if inputs were sufficient
// - if 'pkis' (the other participants' KI components) is missing some components
// then 'ki' will not be complete
return true;
}
//----------------------------------------------------------------------------------------------------------------------
} //namespace multisig
|
