// Copyright (c) 2016, Monero Research Labs // // Author: Shen Noether // // 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 "misc_log_ex.h" #include "common/perf_timer.h" #include "common/threadpool.h" #include "common/util.h" #include "rctSigs.h" #include "bulletproofs.h" #include "cryptonote_basic/cryptonote_format_utils.h" using namespace crypto; using namespace std; #undef MONERO_DEFAULT_LOG_CATEGORY #define MONERO_DEFAULT_LOG_CATEGORY "ringct" namespace rct { Bulletproof proveRangeBulletproof(key &C, key &mask, uint64_t amount) { mask = rct::skGen(); Bulletproof proof = bulletproof_PROVE(amount, mask); C = proof.V; return proof; } //Borromean (c.f. gmax/andytoshi's paper) boroSig genBorromean(const key64 x, const key64 P1, const key64 P2, const bits indices) { key64 L[2], alpha; key c; int naught = 0, prime = 0, ii = 0, jj=0; boroSig bb; for (ii = 0 ; ii < 64 ; ii++) { naught = indices[ii]; prime = (indices[ii] + 1) % 2; skGen(alpha[ii]); scalarmultBase(L[naught][ii], alpha[ii]); if (naught == 0) { skGen(bb.s1[ii]); c = hash_to_scalar(L[naught][ii]); addKeys2(L[prime][ii], bb.s1[ii], c, P2[ii]); } } bb.ee = hash_to_scalar(L[1]); //or L[1].. key LL, cc; for (jj = 0 ; jj < 64 ; jj++) { if (!indices[jj]) { sc_mulsub(bb.s0[jj].bytes, x[jj].bytes, bb.ee.bytes, alpha[jj].bytes); } else { skGen(bb.s0[jj]); addKeys2(LL, bb.s0[jj], bb.ee, P1[jj]); //different L0 cc = hash_to_scalar(LL); sc_mulsub(bb.s1[jj].bytes, x[jj].bytes, cc.bytes, alpha[jj].bytes); } } return bb; } //see above. bool verifyBorromean(const boroSig &bb, const key64 P1, const key64 P2) { key64 Lv1; key chash, LL; int ii = 0; for (ii = 0 ; ii < 64 ; ii++) { addKeys2(LL, bb.s0[ii], bb.ee, P1[ii]); chash = hash_to_scalar(LL); addKeys2(Lv1[ii], bb.s1[ii], chash, P2[ii]); } key eeComputed = hash_to_scalar(Lv1); //hash function fine return equalKeys(eeComputed, bb.ee); } //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] * Hash(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) { keyV II(xx.size()); size_t i = 0; for (i = 0; i < xx.size(); i++) { II[i] = scalarmultKey(hashToPoint(scalarmultBase(xx[i])), xx[i]); } return II; } //Multilayered Spontaneous Anonymous Group Signatures (MLSAG signatures) //This is a just slghtly more efficient version than the ones described below //(will be explained in more detail in Ring Multisig paper //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] * Hash(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 mgSig MLSAG_Gen(const key &message, const keyM & pk, const keyV & xx, const unsigned int index, size_t dsRows) { mgSig rv; size_t cols = pk.size(); CHECK_AND_ASSERT_THROW_MES(cols >= 2, "Error! What is c if cols = 1!"); CHECK_AND_ASSERT_THROW_MES(index < cols, "Index out of range"); size_t rows = pk[0].size(); CHECK_AND_ASSERT_THROW_MES(rows >= 1, "Empty pk"); for (size_t i = 1; i < cols; ++i) { CHECK_AND_ASSERT_THROW_MES(pk[i].size() == rows, "pk is not rectangular"); } CHECK_AND_ASSERT_THROW_MES(xx.size() == rows, "Bad xx size"); CHECK_AND_ASSERT_THROW_MES(dsRows <= rows, "Bad dsRows size"); size_t i = 0, j = 0, ii = 0; key c, c_old, L, R, Hi; sc_0(c_old.bytes); vector Ip(dsRows); rv.II = keyV(dsRows); keyV alpha(rows); keyV aG(rows); rv.ss = keyM(cols, aG); keyV aHP(dsRows); keyV toHash(1 + 3 * dsRows + 2 * (rows - dsRows)); toHash[0] = message; DP("here1"); for (i = 0; i < dsRows; i++) { skpkGen(alpha[i], aG[i]); //need to save alphas for later.. Hi = hashToPoint(pk[index][i]); aHP[i] = scalarmultKey(Hi, alpha[i]); toHash[3 * i + 1] = pk[index][i]; toHash[3 * i + 2] = aG[i]; toHash[3 * i + 3] = aHP[i]; rv.II[i] = scalarmultKey(Hi, xx[i]); precomp(Ip[i].k, rv.II[i]); } size_t ndsRows = 3 * dsRows; //non Double Spendable Rows (see identity chains paper) for (i = dsRows, ii = 0 ; i < rows ; i++, ii++) { skpkGen(alpha[i], aG[i]); //need to save alphas for later.. toHash[ndsRows + 2 * ii + 1] = pk[index][i]; toHash[ndsRows + 2 * ii + 2] = aG[i]; } c_old = hash_to_scalar(toHash); i = (index + 1) % cols; if (i == 0) { copy(rv.cc, c_old); } while (i != index) { rv.ss[i] = skvGen(rows); sc_0(c.bytes); for (j = 0; j < dsRows; j++) { addKeys2(L, rv.ss[i][j], c_old, pk[i][j]); hashToPoint(Hi, pk[i][j]); addKeys3(R, rv.ss[i][j], Hi, c_old, Ip[j].k); toHash[3 * j + 1] = pk[i][j]; toHash[3 * j + 2] = L; toHash[3 * j + 3] = R; } for (j = dsRows, ii = 0; j < rows; j++, ii++) { addKeys2(L, rv.ss[i][j], c_old, pk[i][j]); toHash[ndsRows + 2 * ii + 1] = pk[i][j]; toHash[ndsRows + 2 * ii + 2] = L; } c = hash_to_scalar(toHash); copy(c_old, c); i = (i + 1) % cols; if (i == 0) { copy(rv.cc, c_old); } } for (j = 0; j < rows; j++) { sc_mulsub(rv.ss[index][j].bytes, c.bytes, xx[j].bytes, alpha[j].bytes); } return rv; } //Multilayered Spontaneous Anonymous Group Signatures (MLSAG signatures) //This is a just slghtly more efficient version than the ones described below //(will be explained in more detail in Ring Multisig paper //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] * Hash(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 bool MLSAG_Ver(const key &message, const keyM & pk, const mgSig & rv, size_t dsRows) { size_t cols = pk.size(); CHECK_AND_ASSERT_MES(cols >= 2, false, "Error! What is c if cols = 1!"); size_t rows = pk[0].size(); CHECK_AND_ASSERT_MES(rows >= 1, false, "Empty pk"); for (size_t i = 1; i < cols; ++i) { CHECK_AND_ASSERT_MES(pk[i].size() == rows, false, "pk is not rectangular"); } CHECK_AND_ASSERT_MES(rv.II.size() == dsRows, false, "Bad II size"); CHECK_AND_ASSERT_MES(rv.ss.size() == cols, false, "Bad rv.ss size"); for (size_t i = 0; i < cols; ++i) { CHECK_AND_ASSERT_MES(rv.ss[i].size() == rows, false, "rv.ss is not rectangular"); } CHECK_AND_ASSERT_MES(dsRows <= rows, false, "Bad dsRows value"); for (size_t i = 0; i < rv.ss.size(); ++i) for (size_t j = 0; j < rv.ss[i].size(); ++j) CHECK_AND_ASSERT_MES(sc_check(rv.ss[i][j].bytes) == 0, false, "Bad ss slot"); CHECK_AND_ASSERT_MES(sc_check(rv.cc.bytes) == 0, false, "Bad cc"); size_t i = 0, j = 0, ii = 0; key c, L, R, Hi; key c_old = copy(rv.cc); vector Ip(dsRows); for (i = 0 ; i < dsRows ; i++) { precomp(Ip[i].k, rv.II[i]); } size_t ndsRows = 3 * dsRows; //non Double Spendable Rows (see identity chains paper keyV toHash(1 + 3 * dsRows + 2 * (rows - dsRows)); toHash[0] = message; i = 0; while (i < cols) { sc_0(c.bytes); for (j = 0; j < dsRows; j++) { addKeys2(L, rv.ss[i][j], c_old, pk[i][j]); hashToPoint(Hi, pk[i][j]); addKeys3(R, rv.ss[i][j], Hi, c_old, Ip[j].k); toHash[3 * j + 1] = pk[i][j]; toHash[3 * j + 2] = L; toHash[3 * j + 3] = R; } for (j = dsRows, ii = 0 ; j < rows ; j++, ii++) { addKeys2(L, rv.ss[i][j], c_old, pk[i][j]); toHash[ndsRows + 2 * ii + 1] = pk[i][j]; toHash[ndsRows + 2 * ii + 2] = L; } c = hash_to_scalar(toHash); copy(c_old, c); i = (i + 1); } sc_sub(c.bytes, c_old.bytes, rv.cc.bytes); return sc_isnonzero(c.bytes) == 0; } //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) { sc_0(mask.bytes); identity(C); bits b; d2b(b, amount); rangeSig sig; key64 ai; key64 CiH; int i = 0; for (i = 0; i < ATOMS; i++) { skGen(ai[i]); if (b[i] == 0) { scalarmultBase(sig.Ci[i], ai[i]); } if (b[i] == 1) { addKeys1(sig.Ci[i], ai[i], H2[i]); } subKeys(CiH[i], sig.Ci[i], H2[i]); sc_add(mask.bytes, mask.bytes, ai[i].bytes); addKeys(C, C, sig.Ci[i]); } sig.asig = genBorromean(ai, sig.Ci, CiH, b); return sig; } //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 bool verRange(const key & C, const rangeSig & as) { try { PERF_TIMER(verRange); key64 CiH; int i = 0; key Ctmp = identity(); for (i = 0; i < 64; i++) { subKeys(CiH[i], as.Ci[i], H2[i]); addKeys(Ctmp, Ctmp, as.Ci[i]); } if (!equalKeys(C, Ctmp)) return false; if (!verifyBorromean(as.asig, as.Ci, CiH)) return false; return true; } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (...) { return false; } } key get_pre_mlsag_hash(const rctSig &rv) { keyV hashes; hashes.reserve(3); hashes.push_back(rv.message); crypto::hash h; std::stringstream ss; binary_archive ba(ss); const size_t inputs = rv.pseudoOuts.size(); const size_t outputs = rv.ecdhInfo.size(); CHECK_AND_ASSERT_THROW_MES(const_cast(rv).serialize_rctsig_base(ba, inputs, outputs), "Failed to serialize rctSigBase"); cryptonote::get_blob_hash(ss.str(), h); hashes.push_back(hash2rct(h)); keyV kv; kv.reserve((64*3+1) * rv.p.rangeSigs.size()); for (auto r: rv.p.rangeSigs) { for (size_t n = 0; n < 64; ++n) kv.push_back(r.asig.s0[n]); for (size_t n = 0; n < 64; ++n) kv.push_back(r.asig.s1[n]); kv.push_back(r.asig.ee); for (size_t n = 0; n < 64; ++n) kv.push_back(r.Ci[n]); } hashes.push_back(cn_fast_hash(kv)); return cn_fast_hash(hashes); } //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 key &message, const ctkeyM & pubs, const ctkeyV & inSk, const ctkeyV &outSk, const ctkeyV & outPk, unsigned int index, key txnFeeKey) { mgSig mg; //setup vars size_t cols = pubs.size(); CHECK_AND_ASSERT_THROW_MES(cols >= 1, "Empty pubs"); size_t rows = pubs[0].size(); CHECK_AND_ASSERT_THROW_MES(rows >= 1, "Empty pubs"); for (size_t i = 1; i < cols; ++i) { CHECK_AND_ASSERT_THROW_MES(pubs[i].size() == rows, "pubs is not rectangular"); } CHECK_AND_ASSERT_THROW_MES(inSk.size() == rows, "Bad inSk size"); CHECK_AND_ASSERT_THROW_MES(outSk.size() == outPk.size(), "Bad outSk/outPk size"); keyV sk(rows + 1); keyV tmp(rows + 1); size_t i = 0, j = 0; for (i = 0; i < rows + 1; i++) { sc_0(sk[i].bytes); identity(tmp[i]); } keyM M(cols, tmp); //create the matrix to mg sig for (i = 0; i < cols; i++) { M[i][rows] = identity(); for (j = 0; j < rows; j++) { M[i][j] = pubs[i][j].dest; addKeys(M[i][rows], M[i][rows], pubs[i][j].mask); //add input commitments in last row } } sc_0(sk[rows].bytes); for (j = 0; j < rows; j++) { sk[j] = copy(inSk[j].dest); sc_add(sk[rows].bytes, sk[rows].bytes, inSk[j].mask.bytes); //add masks in last row } for (i = 0; i < cols; i++) { for (size_t j = 0; j < outPk.size(); j++) { subKeys(M[i][rows], M[i][rows], outPk[j].mask); //subtract output Ci's in last row } //subtract txn fee output in last row subKeys(M[i][rows], M[i][rows], txnFeeKey); } for (size_t j = 0; j < outPk.size(); j++) { sc_sub(sk[rows].bytes, sk[rows].bytes, outSk[j].mask.bytes); //subtract output masks in last row.. } return MLSAG_Gen(message, M, sk, index, rows); } //Ring-ct MG sigs Simple // Simple version for when we assume only // post rct inputs // here pubs is a vector of (P, C) length mixin // inSk is x, a_in corresponding to signing index // a_out, Cout is for the output commitment // index is the signing index.. mgSig proveRctMGSimple(const key &message, const ctkeyV & pubs, const ctkey & inSk, const key &a , const key &Cout, unsigned int index) { mgSig mg; //setup vars size_t rows = 1; size_t cols = pubs.size(); CHECK_AND_ASSERT_THROW_MES(cols >= 1, "Empty pubs"); keyV tmp(rows + 1); keyV sk(rows + 1); size_t i; keyM M(cols, tmp); for (i = 0; i < cols; i++) { M[i][0] = pubs[i].dest; subKeys(M[i][1], pubs[i].mask, Cout); sk[0] = copy(inSk.dest); sc_sub(sk[1].bytes, inSk.mask.bytes, a.bytes); } return MLSAG_Gen(message, M, sk, index, rows); } //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 bool verRctMG(const mgSig &mg, const ctkeyM & pubs, const ctkeyV & outPk, key txnFeeKey, const key &message) { PERF_TIMER(verRctMG); //setup vars size_t cols = pubs.size(); CHECK_AND_ASSERT_MES(cols >= 1, false, "Empty pubs"); size_t rows = pubs[0].size(); CHECK_AND_ASSERT_MES(rows >= 1, false, "Empty pubs"); for (size_t i = 1; i < cols; ++i) { CHECK_AND_ASSERT_MES(pubs[i].size() == rows, false, "pubs is not rectangular"); } keyV tmp(rows + 1); size_t i = 0, j = 0; for (i = 0; i < rows + 1; i++) { identity(tmp[i]); } keyM M(cols, tmp); //create the matrix to mg sig for (j = 0; j < rows; j++) { for (i = 0; i < cols; i++) { M[i][j] = pubs[i][j].dest; addKeys(M[i][rows], M[i][rows], pubs[i][j].mask); //add Ci in last row } } for (i = 0; i < cols; i++) { for (j = 0; j < outPk.size(); j++) { subKeys(M[i][rows], M[i][rows], outPk[j].mask); //subtract output Ci's in last row } //subtract txn fee output in last row subKeys(M[i][rows], M[i][rows], txnFeeKey); } return MLSAG_Ver(message, M, mg, rows); } //Ring-ct Simple MG sigs //Ver: //This does a simplified version, assuming only post Rct //inputs bool verRctMGSimple(const key &message, const mgSig &mg, const ctkeyV & pubs, const key & C) { try { PERF_TIMER(verRctMGSimple); //setup vars size_t rows = 1; size_t cols = pubs.size(); CHECK_AND_ASSERT_MES(cols >= 1, false, "Empty pubs"); keyV tmp(rows + 1); size_t i; keyM M(cols, tmp); //create the matrix to mg sig for (i = 0; i < cols; i++) { M[i][0] = pubs[i].dest; subKeys(M[i][1], pubs[i].mask, C); } //DP(C); return MLSAG_Ver(message, M, mg, rows); } catch (...) { return false; } } //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) { a.mask = pkGen(); a.dest = pkGen(); } //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" + 1 columns and one of the columns is inPk // the return value are the key matrix, and the index where inPk was put (random). tuple populateFromBlockchain(ctkeyV inPk, int mixin) { int rows = inPk.size(); ctkeyM rv(mixin + 1, inPk); int index = randXmrAmount(mixin); int i = 0, j = 0; for (i = 0; i <= mixin; i++) { if (i != index) { for (j = 0; j < rows; j++) { getKeyFromBlockchain(rv[i][j], (size_t)randXmrAmount); } } } return make_tuple(rv, index); } //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). xmr_amount populateFromBlockchainSimple(ctkeyV & mixRing, const ctkey & inPk, int mixin) { int index = randXmrAmount(mixin); int i = 0; for (i = 0; i <= mixin; i++) { if (i != index) { getKeyFromBlockchain(mixRing[i], (size_t)randXmrAmount(1000)); } else { mixRing[i] = inPk; } } return index; } //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 // Note: For txn fees, the last index in the amounts vector should contain that // Thus the amounts vector will be "one" longer than the destinations vectort rctSig genRct(const key &message, const ctkeyV & inSk, const keyV & destinations, const vector & amounts, const ctkeyM &mixRing, const keyV &amount_keys, unsigned int index, ctkeyV &outSk, bool bulletproof) { CHECK_AND_ASSERT_THROW_MES(amounts.size() == destinations.size() || amounts.size() == destinations.size() + 1, "Different number of amounts/destinations"); CHECK_AND_ASSERT_THROW_MES(amount_keys.size() == destinations.size(), "Different number of amount_keys/destinations"); CHECK_AND_ASSERT_THROW_MES(index < mixRing.size(), "Bad index into mixRing"); for (size_t n = 0; n < mixRing.size(); ++n) { CHECK_AND_ASSERT_THROW_MES(mixRing[n].size() == inSk.size(), "Bad mixRing size"); } rctSig rv; rv.type = RCTTypeFull; rv.message = message; rv.outPk.resize(destinations.size()); rv.p.rangeSigs.resize(destinations.size()); rv.ecdhInfo.resize(destinations.size()); size_t i = 0; keyV masks(destinations.size()); //sk mask.. outSk.resize(destinations.size()); for (i = 0; i < destinations.size(); i++) { //add destination to sig rv.outPk[i].dest = copy(destinations[i]); //compute range proof if (bulletproof) rv.p.bulletproofs[i] = proveRangeBulletproof(rv.outPk[i].mask, outSk[i].mask, amounts[i]); else rv.p.rangeSigs[i] = proveRange(rv.outPk[i].mask, outSk[i].mask, amounts[i]); #ifdef DBG if (bulletproof) CHECK_AND_ASSERT_THROW_MES(bulletproof_VERIFY(rv.p.bulletproofs[i]), "bulletproof_VERIFY failed on newly created proof"); else CHECK_AND_ASSERT_THROW_MES(verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]), "verRange failed on newly created proof"); #endif //mask amount and mask rv.ecdhInfo[i].mask = copy(outSk[i].mask); rv.ecdhInfo[i].amount = d2h(amounts[i]); ecdhEncode(rv.ecdhInfo[i], amount_keys[i]); } //set txn fee if (amounts.size() > destinations.size()) { rv.txnFee = amounts[destinations.size()]; } else { rv.txnFee = 0; } key txnFeeKey = scalarmultH(d2h(rv.txnFee)); rv.mixRing = mixRing; rv.p.MGs.push_back(proveRctMG(get_pre_mlsag_hash(rv), rv.mixRing, inSk, outSk, rv.outPk, index, txnFeeKey)); return rv; } rctSig genRct(const key &message, const ctkeyV & inSk, const ctkeyV & inPk, const keyV & destinations, const vector & amounts, const keyV &amount_keys, const int mixin) { unsigned int index; ctkeyM mixRing; ctkeyV outSk; tie(mixRing, index) = populateFromBlockchain(inPk, mixin); return genRct(message, inSk, destinations, amounts, mixRing, amount_keys, index, outSk, false); } //RCT simple //for post-rct only rctSig genRctSimple(const key &message, const ctkeyV & inSk, const keyV & destinations, const vector &inamounts, const vector &outamounts, xmr_amount txnFee, const ctkeyM & mixRing, const keyV &amount_keys, const std::vector & index, ctkeyV &outSk, bool bulletproof) { CHECK_AND_ASSERT_THROW_MES(inamounts.size() > 0, "Empty inamounts"); CHECK_AND_ASSERT_THROW_MES(inamounts.size() == inSk.size(), "Different number of inamounts/inSk"); CHECK_AND_ASSERT_THROW_MES(outamounts.size() == destinations.size(), "Different number of amounts/destinations"); CHECK_AND_ASSERT_THROW_MES(amount_keys.size() == destinations.size(), "Different number of amount_keys/destinations"); CHECK_AND_ASSERT_THROW_MES(index.size() == inSk.size(), "Different number of index/inSk"); CHECK_AND_ASSERT_THROW_MES(mixRing.size() == inSk.size(), "Different number of mixRing/inSk"); for (size_t n = 0; n < mixRing.size(); ++n) { CHECK_AND_ASSERT_THROW_MES(index[n] < mixRing[n].size(), "Bad index into mixRing"); } rctSig rv; rv.type = RCTTypeSimple; rv.message = message; rv.outPk.resize(destinations.size()); if (bulletproof) rv.p.bulletproofs.resize(destinations.size()); else rv.p.rangeSigs.resize(destinations.size()); rv.ecdhInfo.resize(destinations.size()); size_t i; keyV masks(destinations.size()); //sk mask.. outSk.resize(destinations.size()); key sumout = zero(); for (i = 0; i < destinations.size(); i++) { //add destination to sig rv.outPk[i].dest = copy(destinations[i]); //compute range proof if (bulletproof) rv.p.bulletproofs[i] = proveRangeBulletproof(rv.outPk[i].mask, outSk[i].mask, outamounts[i]); else rv.p.rangeSigs[i] = proveRange(rv.outPk[i].mask, outSk[i].mask, outamounts[i]); #ifdef DBG if (bulletproof) CHECK_AND_ASSERT_THROW_MES(bulletproof_VERIFY(rv.p.bulletproofs[i]), "bulletproof_VERIFY failed on newly created proof"); else CHECK_AND_ASSERT_THROW_MES(verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]), "verRange failed on newly created proof"); #endif sc_add(sumout.bytes, outSk[i].mask.bytes, sumout.bytes); //mask amount and mask rv.ecdhInfo[i].mask = copy(outSk[i].mask); rv.ecdhInfo[i].amount = d2h(outamounts[i]); ecdhEncode(rv.ecdhInfo[i], amount_keys[i]); } //set txn fee rv.txnFee = txnFee; // TODO: unused ?? // key txnFeeKey = scalarmultH(d2h(rv.txnFee)); rv.mixRing = mixRing; rv.pseudoOuts.resize(inamounts.size()); rv.p.MGs.resize(inamounts.size()); key sumpouts = zero(); //sum pseudoOut masks keyV a(inamounts.size()); for (i = 0 ; i < inamounts.size() - 1; i++) { skGen(a[i]); sc_add(sumpouts.bytes, a[i].bytes, sumpouts.bytes); genC(rv.pseudoOuts[i], a[i], inamounts[i]); } rv.mixRing = mixRing; sc_sub(a[i].bytes, sumout.bytes, sumpouts.bytes); genC(rv.pseudoOuts[i], a[i], inamounts[i]); DP(rv.pseudoOuts[i]); key full_message = get_pre_mlsag_hash(rv); for (i = 0 ; i < inamounts.size(); i++) { rv.p.MGs[i] = proveRctMGSimple(full_message, rv.mixRing[i], inSk[i], a[i], rv.pseudoOuts[i], index[i]); } return rv; } rctSig genRctSimple(const key &message, const ctkeyV & inSk, const ctkeyV & inPk, const keyV & destinations, const vector &inamounts, const vector &outamounts, const keyV &amount_keys, xmr_amount txnFee, unsigned int mixin) { std::vector index; index.resize(inPk.size()); ctkeyM mixRing; ctkeyV outSk; mixRing.resize(inPk.size()); for (size_t i = 0; i < inPk.size(); ++i) { mixRing[i].resize(mixin+1); index[i] = populateFromBlockchainSimple(mixRing[i], inPk[i], mixin); } return genRctSimple(message, inSk, destinations, inamounts, outamounts, txnFee, mixRing, amount_keys, index, outSk, false); } //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 bool verRct(const rctSig & rv, bool semantics) { PERF_TIMER(verRct); CHECK_AND_ASSERT_MES(rv.type == RCTTypeFull, false, "verRct called on non-full rctSig"); if (semantics) { if (rv.p.rangeSigs.empty()) CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.bulletproofs.size(), false, "Mismatched sizes of outPk and rv.p.bulletproofs"); else CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.rangeSigs.size(), false, "Mismatched sizes of outPk and rv.p.rangeSigs"); CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.ecdhInfo.size(), false, "Mismatched sizes of outPk and rv.ecdhInfo"); CHECK_AND_ASSERT_MES(rv.p.MGs.size() == 1, false, "full rctSig has not one MG"); } else { // semantics check is early, we don't have the MGs resolved yet } // some rct ops can throw try { if (semantics) { tools::threadpool& tpool = tools::threadpool::getInstance(); tools::threadpool::waiter waiter; std::deque results(rv.outPk.size(), false); DP("range proofs verified?"); for (size_t i = 0; i < rv.outPk.size(); i++) { tpool.submit(&waiter, [&, i] { if (rv.p.rangeSigs.empty()) results[i] = bulletproof_VERIFY(rv.p.bulletproofs[i]); // TODO else results[i] = verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]); }); } waiter.wait(); for (size_t i = 0; i < rv.outPk.size(); ++i) { if (!results[i]) { LOG_PRINT_L1("Range proof verified failed for output " << i); return false; } } } if (!semantics) { //compute txn fee key txnFeeKey = scalarmultH(d2h(rv.txnFee)); bool mgVerd = verRctMG(rv.p.MGs[0], rv.mixRing, rv.outPk, txnFeeKey, get_pre_mlsag_hash(rv)); DP("mg sig verified?"); DP(mgVerd); if (!mgVerd) { LOG_PRINT_L1("MG signature verification failed"); return false; } } return true; } catch(...) { return false; } } //ver RingCT simple //assumes only post-rct style inputs (at least for max anonymity) bool verRctSimple(const rctSig & rv, bool semantics) { try { PERF_TIMER(verRctSimple); CHECK_AND_ASSERT_MES(rv.type == RCTTypeSimple, false, "verRctSimple called on non simple rctSig"); if (semantics) { if (rv.p.rangeSigs.empty()) CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.bulletproofs.size(), false, "Mismatched sizes of outPk and rv.p.bulletproofs"); else CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.rangeSigs.size(), false, "Mismatched sizes of outPk and rv.p.rangeSigs"); CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.ecdhInfo.size(), false, "Mismatched sizes of outPk and rv.ecdhInfo"); CHECK_AND_ASSERT_MES(rv.pseudoOuts.size() == rv.p.MGs.size(), false, "Mismatched sizes of rv.pseudoOuts and rv.p.MGs"); } else { // semantics check is early, and mixRing/MGs aren't resolved yet CHECK_AND_ASSERT_MES(rv.pseudoOuts.size() == rv.mixRing.size(), false, "Mismatched sizes of rv.pseudoOuts and mixRing"); } const size_t threads = std::max(rv.outPk.size(), rv.mixRing.size()); std::deque results(threads); tools::threadpool& tpool = tools::threadpool::getInstance(); tools::threadpool::waiter waiter; if (semantics) { key sumOutpks = identity(); for (size_t i = 0; i < rv.outPk.size(); i++) { addKeys(sumOutpks, sumOutpks, rv.outPk[i].mask); } DP(sumOutpks); key txnFeeKey = scalarmultH(d2h(rv.txnFee)); addKeys(sumOutpks, txnFeeKey, sumOutpks); key sumPseudoOuts = identity(); for (size_t i = 0 ; i < rv.pseudoOuts.size() ; i++) { addKeys(sumPseudoOuts, sumPseudoOuts, rv.pseudoOuts[i]); } DP(sumPseudoOuts); //check pseudoOuts vs Outs.. if (!equalKeys(sumPseudoOuts, sumOutpks)) { LOG_PRINT_L1("Sum check failed"); return false; } results.clear(); results.resize(rv.outPk.size()); for (size_t i = 0; i < rv.outPk.size(); i++) { tpool.submit(&waiter, [&, i] { if (rv.p.rangeSigs.empty()) results[i] = bulletproof_VERIFY(rv.p.bulletproofs[i]); else results[i] = verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]); }); } waiter.wait(); for (size_t i = 0; i < results.size(); ++i) { if (!results[i]) { LOG_PRINT_L1("Range proof verified failed for output " << i); return false; } } } else { const key message = get_pre_mlsag_hash(rv); results.clear(); results.resize(rv.mixRing.size()); for (size_t i = 0 ; i < rv.mixRing.size() ; i++) { tpool.submit(&waiter, [&, i] { results[i] = verRctMGSimple(message, rv.p.MGs[i], rv.mixRing[i], rv.pseudoOuts[i]); }); } waiter.wait(); for (size_t i = 0; i < results.size(); ++i) { if (!results[i]) { LOG_PRINT_L1("verRctMGSimple failed for input " << i); return false; } } } return true; } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (...) { return false; } } //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 xmr_amount decodeRct(const rctSig & rv, const key & sk, unsigned int i, key & mask) { CHECK_AND_ASSERT_MES(rv.type == RCTTypeFull, false, "decodeRct called on non-full rctSig"); CHECK_AND_ASSERT_THROW_MES(rv.outPk.size() == rv.ecdhInfo.size(), "Mismatched sizes of rv.outPk and rv.ecdhInfo"); CHECK_AND_ASSERT_THROW_MES(i < rv.ecdhInfo.size(), "Bad index"); //mask amount and mask ecdhTuple ecdh_info = rv.ecdhInfo[i]; ecdhDecode(ecdh_info, sk); mask = ecdh_info.mask; key amount = ecdh_info.amount; key C = rv.outPk[i].mask; DP("C"); DP(C); key Ctmp; addKeys2(Ctmp, mask, amount, H); DP("Ctmp"); DP(Ctmp); if (equalKeys(C, Ctmp) == false) { CHECK_AND_ASSERT_THROW_MES(false, "warning, amount decoded incorrectly, will be unable to spend"); } return h2d(amount); } xmr_amount decodeRct(const rctSig & rv, const key & sk, unsigned int i) { key mask; return decodeRct(rv, sk, i, mask); } xmr_amount decodeRctSimple(const rctSig & rv, const key & sk, unsigned int i, key &mask) { CHECK_AND_ASSERT_MES(rv.type == RCTTypeSimple, false, "decodeRct called on non simple rctSig"); CHECK_AND_ASSERT_THROW_MES(rv.outPk.size() == rv.ecdhInfo.size(), "Mismatched sizes of rv.outPk and rv.ecdhInfo"); CHECK_AND_ASSERT_THROW_MES(i < rv.ecdhInfo.size(), "Bad index"); //mask amount and mask ecdhTuple ecdh_info = rv.ecdhInfo[i]; ecdhDecode(ecdh_info, sk); mask = ecdh_info.mask; key amount = ecdh_info.amount; key C = rv.outPk[i].mask; DP("C"); DP(C); key Ctmp; addKeys2(Ctmp, mask, amount, H); DP("Ctmp"); DP(Ctmp); if (equalKeys(C, Ctmp) == false) { CHECK_AND_ASSERT_THROW_MES(false, "warning, amount decoded incorrectly, will be unable to spend"); } return h2d(amount); } xmr_amount decodeRctSimple(const rctSig & rv, const key & sk, unsigned int i) { key mask; return decodeRctSimple(rv, sk, i, mask); } }