aboutsummaryrefslogtreecommitdiff
path: root/src/ringct/rctSigs.h
blob: bf9d4be816730c7f883ecaf453e968f2e4083e0b (plain) (blame)
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
141
142
143
144
145
146
147
148
149
150
151
152
// Copyright (c) 2016, Monero Research Labs
//
// Author: Shen Noether <shen.noether@gmx.com>
//
// 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

//#define DBG

#ifndef RCTSIGS_H
#define RCTSIGS_H

#include <cstddef>
#include <mutex>
#include <vector>
#include <tuple>

#include "crypto/generic-ops.h"

extern "C" {
#include "crypto/random.h"
#include "crypto/keccak.h"
}
#include "crypto/crypto.h"


#include "rctTypes.h"
#include "rctOps.h"

//Define this flag when debugging to get additional info on the console
#ifdef DBG
#define DP(x) dp(x)
#else
#define DP(x)
#endif



using namespace std;
using namespace crypto;

namespace rct {

    //Schnorr Non-linkable
    //Gen Gives a signature (L1, s1, s2) proving that the sender knows "x" such that xG = one of P1 or P2
    //Ver Verifies that signer knows an "x" such that xG = one of P1 or P2
    //These are called in the below ASNL sig generation
    void GenSchnorrNonLinkable(key & L1, key & s1, key & s2, const key & x, const key & P1, const key & P2, int index);
    bool VerSchnorrNonLinkable(const key & P1, const key & P2, const key & L1, const key & s1, const key & s2);

    //Aggregate Schnorr Non-linkable Ring Signature (ASNL)
    // c.f. http://eprint.iacr.org/2015/1098 section 5.
    // These are used in range proofs (alternatively Borromean could be used)
    // Gen gives a signature which proves the signer knows, for each i,
    //   an x[i] such that x[i]G = one of P1[i] or P2[i]
    // Ver Verifies the signer knows a key for one of P1[i], P2[i] at each i
    asnlSig GenASNL(key64 x, key64 P1, key64 P2, bits indices);
    bool VerASNL(const key64 P1, const key64 P2, const asnlSig &as);

    //Multilayered Spontaneous Anonymous Group Signatures (MLSAG signatures)
    //These are aka MG signatutes in earlier drafts of the ring ct paper
    // c.f. http://eprint.iacr.org/2015/1098 section 2.
    // keyImageV just does I[i] = xx[i] * HashToPoint(xx[i] * G) for each i
    // Gen creates a signature which proves that for some column in the keymatrix "pk"
    //   the signer knows a secret key for each row in that column
    // Ver verifies that the MG sig was created correctly
    keyV keyImageV(const keyV &xx);
    mgSig MLSAG_Gen(key message, const keyM & pk, const keyV & xx, const unsigned int index, size_t dsRows);
    bool MLSAG_Ver(key message, const keyM &pk, const mgSig &sig, size_t dsRows);
    //mgSig MLSAG_Gen_Old(const keyM & pk, const keyV & xx, const int index);

    //proveRange and verRange
    //proveRange gives C, and mask such that \sumCi = C
    //   c.f. http://eprint.iacr.org/2015/1098 section 5.1
    //   and Ci is a commitment to either 0 or 2^i, i=0,...,63
    //   thus this proves that "amount" is in [0, 2^64]
    //   mask is a such that C = aG + bH, and b = amount
    //verRange verifies that \sum Ci = C and that each Ci is a commitment to 0 or 2^i
    rangeSig proveRange(key & C, key & mask, const xmr_amount & amount);
    bool verRange(const key & C, const rangeSig & as);

    //Ring-ct MG sigs
    //Prove:
    //   c.f. http://eprint.iacr.org/2015/1098 section 4. definition 10.
    //   This does the MG sig on the "dest" part of the given key matrix, and
    //   the last row is the sum of input commitments from that column - sum output commitments
    //   this shows that sum inputs = sum outputs
    //Ver:
    //   verifies the above sig is created corretly
    mgSig proveRctMG(const ctkeyM & pubs, const ctkeyV & inSk, const keyV &outMasks, const ctkeyV & outPk, unsigned int index, key txnFee, const key &message);
    mgSig proveRctMGSimple(const key & message, const ctkeyV & pubs, const ctkey & inSk, const key &a , const key &Cout, unsigned int index);
    bool verRctMG(mgSig mg, const ctkeyM & pubs, const ctkeyV & outPk, key txnFee, const key &message);
    bool verRctMGSimple(const key &message, const mgSig &mg, const ctkeyV & pubs, const key & C);

    //These functions get keys from blockchain
    //replace these when connecting blockchain
    //getKeyFromBlockchain grabs a key from the blockchain at "reference_index" to mix with
    //populateFromBlockchain creates a keymatrix with "mixin" columns and one of the columns is inPk
    //   the return value are the key matrix, and the index where inPk was put (random).
    void getKeyFromBlockchain(ctkey & a, size_t reference_index);
    tuple<ctkeyM, xmr_amount> populateFromBlockchain(ctkeyV inPk, int mixin);

    //RingCT protocol
    //genRct:
    //   creates an rctSig with all data necessary to verify the rangeProofs and that the signer owns one of the
    //   columns that are claimed as inputs, and that the sum of inputs  = sum of outputs.
    //   Also contains masked "amount" and "mask" so the receiver can see how much they received
    //verRct:
    //   verifies that all signatures (rangeProogs, MG sig, sum inputs = outputs) are correct
    //decodeRct: (c.f. http://eprint.iacr.org/2015/1098 section 5.1.1)
    //   uses the attached ecdh info to find the amounts represented by each output commitment
    //   must know the destination private key to find the correct amount, else will return a random number
    rctSig genRct(const key &message, const ctkeyV & inSk, const keyV & destinations, const vector<xmr_amount> & amounts, const ctkeyM &mixRing, const keyV &amount_keys, unsigned int index, ctkeyV &outSk);
    rctSig genRct(const key &message, const ctkeyV & inSk, const ctkeyV  & inPk, const keyV & destinations, const vector<xmr_amount> & amounts, const keyV &amount_keys, const int mixin);
    rctSig genRctSimple(const key & message, const ctkeyV & inSk, const ctkeyV & inPk, const keyV & destinations, const vector<xmr_amount> & inamounts, const vector<xmr_amount> & outamounts, const keyV &amount_keys, xmr_amount txnFee, unsigned int mixin);
    rctSig genRctSimple(const key & message, const ctkeyV & inSk, const keyV & destinations, const vector<xmr_amount> & inamounts, const vector<xmr_amount> & outamounts, xmr_amount txnFee, const ctkeyM & mixRing, const keyV &amount_keys, const std::vector<unsigned int> & index, ctkeyV &outSk);
    bool verRct(const rctSig & rv);
    bool verRctSimple(const rctSig & rv);
    xmr_amount decodeRct(const rctSig & rv, const key & sk, unsigned int i, key & mask);
    xmr_amount decodeRctFromSharedSecret(const rctSig & rv, const key & sk, unsigned int i, key & mask);
    xmr_amount decodeRct(const rctSig & rv, const key & sk, unsigned int i);
    xmr_amount decodeRctSimpleFromSharedSecret(const rctSig & rv, const key & sk, unsigned int i, key & mask);
    xmr_amount decodeRctSimple(const rctSig & rv, const key & sk, unsigned int i, key & mask);
    xmr_amount decodeRctSimple(const rctSig & rv, const key & sk, unsigned int i);
}
#endif  /* RCTSIGS_H */