// 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 "misc_language.h" #include "common/perf_timer.h" #include "common/threadpool.h" #include "common/util.h" #include "rctSigs.h" #include "bulletproofs.h" #include "bulletproofs_plus.h" #include "cryptonote_basic/cryptonote_format_utils.h" #include "cryptonote_config.h" using namespace crypto; using namespace std; #undef MONERO_DEFAULT_LOG_CATEGORY #define MONERO_DEFAULT_LOG_CATEGORY "ringct" #define CHECK_AND_ASSERT_MES_L1(expr, ret, message) {if(!(expr)) {MCERROR("verify", message); return ret;}} namespace { rct::Bulletproof make_dummy_bulletproof(const std::vector &outamounts, rct::keyV &C, rct::keyV &masks) { const size_t n_outs = outamounts.size(); const rct::key I = rct::identity(); size_t nrl = 0; while ((1u << nrl) < n_outs) ++nrl; nrl += 6; C.resize(n_outs); masks.resize(n_outs); for (size_t i = 0; i < n_outs; ++i) { masks[i] = I; rct::key sv8, sv; sv = rct::zero(); sv.bytes[0] = outamounts[i] & 255; sv.bytes[1] = (outamounts[i] >> 8) & 255; sv.bytes[2] = (outamounts[i] >> 16) & 255; sv.bytes[3] = (outamounts[i] >> 24) & 255; sv.bytes[4] = (outamounts[i] >> 32) & 255; sv.bytes[5] = (outamounts[i] >> 40) & 255; sv.bytes[6] = (outamounts[i] >> 48) & 255; sv.bytes[7] = (outamounts[i] >> 56) & 255; sc_mul(sv8.bytes, sv.bytes, rct::INV_EIGHT.bytes); rct::addKeys2(C[i], rct::INV_EIGHT, sv8, rct::H); } return rct::Bulletproof{rct::keyV(n_outs, I), I, I, I, I, I, I, rct::keyV(nrl, I), rct::keyV(nrl, I), I, I, I}; } rct::BulletproofPlus make_dummy_bulletproof_plus(const std::vector &outamounts, rct::keyV &C, rct::keyV &masks) { const size_t n_outs = outamounts.size(); const rct::key I = rct::identity(); size_t nrl = 0; while ((1u << nrl) < n_outs) ++nrl; nrl += 6; C.resize(n_outs); masks.resize(n_outs); for (size_t i = 0; i < n_outs; ++i) { masks[i] = I; rct::key sv8, sv; sv = rct::zero(); sv.bytes[0] = outamounts[i] & 255; sv.bytes[1] = (outamounts[i] >> 8) & 255; sv.bytes[2] = (outamounts[i] >> 16) & 255; sv.bytes[3] = (outamounts[i] >> 24) & 255; sv.bytes[4] = (outamounts[i] >> 32) & 255; sv.bytes[5] = (outamounts[i] >> 40) & 255; sv.bytes[6] = (outamounts[i] >> 48) & 255; sv.bytes[7] = (outamounts[i] >> 56) & 255; sc_mul(sv8.bytes, sv.bytes, rct::INV_EIGHT.bytes); rct::addKeys2(C[i], rct::INV_EIGHT, sv8, rct::H); } return rct::BulletproofPlus{rct::keyV(n_outs, I), I, I, I, I, I, I, rct::keyV(nrl, I), rct::keyV(nrl, I)}; } rct::clsag make_dummy_clsag(size_t ring_size) { const rct::key I = rct::identity(); const size_t n_scalars = ring_size; return rct::clsag{rct::keyV(n_scalars, I), I, I, I}; } } namespace rct { Bulletproof proveRangeBulletproof(keyV &C, keyV &masks, const std::vector &amounts, epee::span sk, hw::device &hwdev) { CHECK_AND_ASSERT_THROW_MES(amounts.size() == sk.size(), "Invalid amounts/sk sizes"); masks.resize(amounts.size()); for (size_t i = 0; i < masks.size(); ++i) masks[i] = hwdev.genCommitmentMask(sk[i]); Bulletproof proof = bulletproof_PROVE(amounts, masks); CHECK_AND_ASSERT_THROW_MES(proof.V.size() == amounts.size(), "V does not have the expected size"); C = proof.V; return proof; } Bulletproof proveRangeBulletproof_old(key &C, key &mask, uint64_t amount) { mask = rct::skGen(); Bulletproof proof = bulletproof_PROVE_old(amount, mask); CHECK_AND_ASSERT_THROW_MES(proof.V.size() == 1, "V has not exactly one element"); C = proof.V[0]; return proof; } Bulletproof proveRangeBulletproof_old(keyV &C, keyV &masks, const std::vector &amounts) { masks = rct::skvGen(amounts.size()); Bulletproof proof = bulletproof_PROVE_old(amounts, masks); CHECK_AND_ASSERT_THROW_MES(proof.V.size() == amounts.size(), "V does not have the expected size"); C = proof.V; return proof; } bool verBulletproof(const Bulletproof &proof) { try { return bulletproof_VERIFY(proof); } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (...) { return false; } } bool verBulletproof(const std::vector &proofs) { try { return bulletproof_VERIFY(proofs); } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (...) { return false; } } bool verBulletproof_old(const Bulletproof &proof) { try { return bulletproof_VERIFY_old(proof); } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (...) { return false; } } bool verBulletproof_old(const std::vector &proofs) { try { return bulletproof_VERIFY_old(proofs); } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (...) { return false; } } BulletproofPlus proveRangeBulletproofPlus(keyV &C, keyV &masks, const std::vector &amounts, epee::span sk, hw::device &hwdev) { CHECK_AND_ASSERT_THROW_MES(amounts.size() == sk.size(), "Invalid amounts/sk sizes"); masks.resize(amounts.size()); for (size_t i = 0; i < masks.size(); ++i) masks[i] = hwdev.genCommitmentMask(sk[i]); BulletproofPlus proof = bulletproof_plus_PROVE(amounts, masks); CHECK_AND_ASSERT_THROW_MES(proof.V.size() == amounts.size(), "V does not have the expected size"); C = proof.V; return proof; } bool verBulletproofPlus(const BulletproofPlus &proof) { try { return bulletproof_plus_VERIFY(proof); } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (...) { return false; } } bool verBulletproofPlus(const std::vector &proofs) { try { return bulletproof_plus_VERIFY(proofs); } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (...) { return false; } } //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; auto wiper = epee::misc_utils::create_scope_leave_handler([&](){memwipe(alpha, sizeof(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 ge_p3 P1[64], const ge_p3 P2[64]) { key64 Lv1; key chash, LL; int ii = 0; ge_p2 p2; for (ii = 0 ; ii < 64 ; ii++) { // equivalent of: addKeys2(LL, bb.s0[ii], bb.ee, P1[ii]); ge_double_scalarmult_base_vartime(&p2, bb.ee.bytes, &P1[ii], bb.s0[ii].bytes); ge_tobytes(LL.bytes, &p2); chash = hash_to_scalar(LL); // equivalent of: addKeys2(Lv1[ii], bb.s1[ii], chash, P2[ii]); ge_double_scalarmult_base_vartime(&p2, chash.bytes, &P2[ii], bb.s1[ii].bytes); ge_tobytes(Lv1[ii].bytes, &p2); } key eeComputed = hash_to_scalar(Lv1); //hash function fine return equalKeys(eeComputed, bb.ee); } bool verifyBorromean(const boroSig &bb, const key64 P1, const key64 P2) { ge_p3 P1_p3[64], P2_p3[64]; for (size_t i = 0 ; i < 64 ; ++i) { CHECK_AND_ASSERT_MES_L1(ge_frombytes_vartime(&P1_p3[i], P1[i].bytes) == 0, false, "point conv failed"); CHECK_AND_ASSERT_MES_L1(ge_frombytes_vartime(&P2_p3[i], P2[i].bytes) == 0, false, "point conv failed"); } return verifyBorromean(bb, P1_p3, P2_p3); } // Generate a CLSAG signature // See paper by Goodell et al. (https://eprint.iacr.org/2019/654) // // The keys are set as follows: // P[l] == p*G // C[l] == z*G // C[i] == C_nonzero[i] - C_offset (for hashing purposes) for all i clsag CLSAG_Gen(const key &message, const keyV & P, const key & p, const keyV & C, const key & z, const keyV & C_nonzero, const key & C_offset, const unsigned int l, hw::device &hwdev) { clsag sig; size_t n = P.size(); // ring size CHECK_AND_ASSERT_THROW_MES(n == C.size(), "Signing and commitment key vector sizes must match!"); CHECK_AND_ASSERT_THROW_MES(n == C_nonzero.size(), "Signing and commitment key vector sizes must match!"); CHECK_AND_ASSERT_THROW_MES(l < n, "Signing index out of range!"); // Key images ge_p3 H_p3; hash_to_p3(H_p3,P[l]); key H; ge_p3_tobytes(H.bytes,&H_p3); key D; // Initial values key a; key aG; key aH; hwdev.clsag_prepare(p,z,sig.I,D,H,a,aG,aH); geDsmp I_precomp; geDsmp D_precomp; precomp(I_precomp.k,sig.I); precomp(D_precomp.k,D); // Offset key image scalarmultKey(sig.D,D,INV_EIGHT); // Aggregation hashes keyV mu_P_to_hash(2*n+4); // domain, I, D, P, C, C_offset keyV mu_C_to_hash(2*n+4); // domain, I, D, P, C, C_offset sc_0(mu_P_to_hash[0].bytes); memcpy(mu_P_to_hash[0].bytes,config::HASH_KEY_CLSAG_AGG_0,sizeof(config::HASH_KEY_CLSAG_AGG_0)-1); sc_0(mu_C_to_hash[0].bytes); memcpy(mu_C_to_hash[0].bytes,config::HASH_KEY_CLSAG_AGG_1,sizeof(config::HASH_KEY_CLSAG_AGG_1)-1); for (size_t i = 1; i < n+1; ++i) { mu_P_to_hash[i] = P[i-1]; mu_C_to_hash[i] = P[i-1]; } for (size_t i = n+1; i < 2*n+1; ++i) { mu_P_to_hash[i] = C_nonzero[i-n-1]; mu_C_to_hash[i] = C_nonzero[i-n-1]; } mu_P_to_hash[2*n+1] = sig.I; mu_P_to_hash[2*n+2] = sig.D; mu_P_to_hash[2*n+3] = C_offset; mu_C_to_hash[2*n+1] = sig.I; mu_C_to_hash[2*n+2] = sig.D; mu_C_to_hash[2*n+3] = C_offset; key mu_P, mu_C; mu_P = hash_to_scalar(mu_P_to_hash); mu_C = hash_to_scalar(mu_C_to_hash); // Initial commitment keyV c_to_hash(2*n+5); // domain, P, C, C_offset, message, aG, aH key c; sc_0(c_to_hash[0].bytes); memcpy(c_to_hash[0].bytes,config::HASH_KEY_CLSAG_ROUND,sizeof(config::HASH_KEY_CLSAG_ROUND)-1); for (size_t i = 1; i < n+1; ++i) { c_to_hash[i] = P[i-1]; c_to_hash[i+n] = C_nonzero[i-1]; } c_to_hash[2*n+1] = C_offset; c_to_hash[2*n+2] = message; c_to_hash[2*n+3] = aG; c_to_hash[2*n+4] = aH; hwdev.clsag_hash(c_to_hash,c); size_t i; i = (l + 1) % n; if (i == 0) copy(sig.c1, c); // Decoy indices sig.s = keyV(n); key c_new; key L; key R; key c_p; // = c[i]*mu_P key c_c; // = c[i]*mu_C geDsmp P_precomp; geDsmp C_precomp; geDsmp H_precomp; ge_p3 Hi_p3; while (i != l) { sig.s[i] = skGen(); sc_0(c_new.bytes); sc_mul(c_p.bytes,mu_P.bytes,c.bytes); sc_mul(c_c.bytes,mu_C.bytes,c.bytes); // Precompute points precomp(P_precomp.k,P[i]); precomp(C_precomp.k,C[i]); // Compute L addKeys_aGbBcC(L,sig.s[i],c_p,P_precomp.k,c_c,C_precomp.k); // Compute R hash_to_p3(Hi_p3,P[i]); ge_dsm_precomp(H_precomp.k, &Hi_p3); addKeys_aAbBcC(R,sig.s[i],H_precomp.k,c_p,I_precomp.k,c_c,D_precomp.k); c_to_hash[2*n+3] = L; c_to_hash[2*n+4] = R; hwdev.clsag_hash(c_to_hash,c_new); copy(c,c_new); i = (i + 1) % n; if (i == 0) copy(sig.c1,c); } // Compute final scalar hwdev.clsag_sign(c,a,p,z,mu_P,mu_C,sig.s[l]); memwipe(&a, sizeof(key)); return sig; } clsag CLSAG_Gen(const key &message, const keyV & P, const key & p, const keyV & C, const key & z, const keyV & C_nonzero, const key & C_offset, const unsigned int l) { return CLSAG_Gen(message, P, p, C, z, C_nonzero, C_offset, l, hw::get_device("default")); } // MLSAG signatures // See paper by Noether (https://eprint.iacr.org/2015/1098) // This generalization allows for some dimensions not to require linkability; // this is used in practice for commitment data within signatures // Note that using more than one linkable dimension is not recommended. mgSig MLSAG_Gen(const key &message, const keyM & pk, const keyV & xx, const unsigned int index, size_t dsRows, hw::device &hwdev) { 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; ge_p3 Hi_p3; sc_0(c_old.bytes); vector Ip(dsRows); rv.II = keyV(dsRows); keyV alpha(rows); auto wiper = epee::misc_utils::create_scope_leave_handler([&](){memwipe(alpha.data(), alpha.size() * sizeof(alpha[0]));}); 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++) { toHash[3 * i + 1] = pk[index][i]; hash_to_p3(Hi_p3, pk[index][i]); ge_p3_tobytes(Hi.bytes, &Hi_p3); hwdev.mlsag_prepare(Hi, xx[i], alpha[i] , aG[i] , aHP[i] , rv.II[i]); toHash[3 * i + 2] = aG[i]; toHash[3 * i + 3] = aHP[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]; } hwdev.mlsag_hash(toHash, c_old); 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]); hash_to_p3(Hi_p3, pk[i][j]); ge_p3_tobytes(Hi.bytes, &Hi_p3); 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; } hwdev.mlsag_hash(toHash, c); copy(c_old, c); i = (i + 1) % cols; if (i == 0) { copy(rv.cc, c_old); } } hwdev.mlsag_sign(c, xx, alpha, rows, dsRows, rv.ss[index]); return rv; } // MLSAG signatures // See paper by Noether (https://eprint.iacr.org/2015/1098) // This generalization allows for some dimensions not to require linkability; // this is used in practice for commitment data within signatures // Note that using more than one linkable dimension is not recommended. 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, "Signature must contain more than one public key"); size_t rows = pk[0].size(); CHECK_AND_ASSERT_MES(rows >= 1, false, "Bad total row number"); for (size_t i = 1; i < cols; ++i) { CHECK_AND_ASSERT_MES(pk[i].size() == rows, false, "Bad public key matrix dimensions"); } CHECK_AND_ASSERT_MES(rv.II.size() == dsRows, false, "Wrong number of key images present"); CHECK_AND_ASSERT_MES(rv.ss.size() == cols, false, "Bad scalar matrix dimensions"); for (size_t i = 0; i < cols; ++i) { CHECK_AND_ASSERT_MES(rv.ss[i].size() == rows, false, "Bad scalar matrix dimensions"); } CHECK_AND_ASSERT_MES(dsRows <= rows, false, "Non-double-spend rows cannot exceed total rows"); 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 signature scalar"); } } CHECK_AND_ASSERT_MES(sc_check(rv.cc.bytes) == 0, false, "Bad initial signature hash"); size_t i = 0, j = 0, ii = 0; key c, L, R; key c_old = copy(rv.cc); vector Ip(dsRows); for (i = 0 ; i < dsRows ; i++) { CHECK_AND_ASSERT_MES(!(rv.II[i] == rct::identity()), false, "Bad key image"); precomp(Ip[i].k, rv.II[i]); } size_t ndsRows = 3 * dsRows; // number of dimensions not requiring linkability 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]); // Compute R directly ge_p3 hash8_p3; hash_to_p3(hash8_p3, pk[i][j]); ge_p2 R_p2; ge_double_scalarmult_precomp_vartime(&R_p2, rv.ss[i][j].bytes, &hash8_p3, c_old.bytes, Ip[j].k); ge_tobytes(R.bytes, &R_p2); 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); CHECK_AND_ASSERT_MES(!(c == rct::zero()), false, "Bad signature hash"); 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. https://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. https://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); ge_p3 CiH[64], asCi[64]; int i = 0; ge_p3 Ctmp_p3 = ge_p3_identity; for (i = 0; i < 64; i++) { // faster equivalent of: // subKeys(CiH[i], as.Ci[i], H2[i]); // addKeys(Ctmp, Ctmp, as.Ci[i]); ge_cached cached; ge_p3 p3; ge_p1p1 p1; CHECK_AND_ASSERT_MES_L1(ge_frombytes_vartime(&p3, H2[i].bytes) == 0, false, "point conv failed"); ge_p3_to_cached(&cached, &p3); CHECK_AND_ASSERT_MES_L1(ge_frombytes_vartime(&asCi[i], as.Ci[i].bytes) == 0, false, "point conv failed"); ge_sub(&p1, &asCi[i], &cached); ge_p3_to_cached(&cached, &asCi[i]); ge_p1p1_to_p3(&CiH[i], &p1); ge_add(&p1, &Ctmp_p3, &cached); ge_p1p1_to_p3(&Ctmp_p3, &p1); } key Ctmp; ge_p3_tobytes(Ctmp.bytes, &Ctmp_p3); if (!equalKeys(C, Ctmp)) return false; if (!verifyBorromean(as.asig, asCi, 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, hw::device &hwdev) { keyV hashes; hashes.reserve(3); hashes.push_back(rv.message); crypto::hash h; std::stringstream ss; binary_archive ba(ss); CHECK_AND_ASSERT_THROW_MES(!rv.mixRing.empty(), "Empty mixRing"); const size_t inputs = is_rct_simple(rv.type) ? rv.mixRing.size() : rv.mixRing[0].size(); const size_t outputs = rv.ecdhInfo.size(); key prehash; 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; if (rv.type == RCTTypeBulletproof || rv.type == RCTTypeBulletproof2 || rv.type == RCTTypeSimpleBulletproof || rv.type == RCTTypeFullBulletproof || rv.type == RCTTypeCLSAG) { kv.reserve((6*2+9) * rv.p.bulletproofs.size()); for (const auto &p: rv.p.bulletproofs) { // V are not hashed as they're expanded from outPk.mask // (and thus hashed as part of rctSigBase above) kv.push_back(p.A); kv.push_back(p.S); kv.push_back(p.T1); kv.push_back(p.T2); kv.push_back(p.taux); kv.push_back(p.mu); for (size_t n = 0; n < p.L.size(); ++n) kv.push_back(p.L[n]); for (size_t n = 0; n < p.R.size(); ++n) kv.push_back(p.R[n]); kv.push_back(p.a); kv.push_back(p.b); kv.push_back(p.t); } } else if (rv.type == RCTTypeBulletproofPlus) { kv.reserve((6*2+6) * rv.p.bulletproofs_plus.size()); for (const auto &p: rv.p.bulletproofs_plus) { // V are not hashed as they're expanded from outPk.mask // (and thus hashed as part of rctSigBase above) kv.push_back(p.A); kv.push_back(p.A1); kv.push_back(p.B); kv.push_back(p.r1); kv.push_back(p.s1); kv.push_back(p.d1); for (size_t n = 0; n < p.L.size(); ++n) kv.push_back(p.L[n]); for (size_t n = 0; n < p.R.size(); ++n) kv.push_back(p.R[n]); } } else { kv.reserve((64*3+1) * rv.p.rangeSigs.size()); for (const 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)); hwdev.mlsag_prehash(ss.str(), inputs, outputs, hashes, rv.outPk, prehash); return prehash; } //Ring-ct MG sigs //Prove: // c.f. https://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, const key &txnFeeKey, hw::device &hwdev) { //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.. } mgSig result = MLSAG_Gen(message, M, sk, index, rows, hwdev); memwipe(sk.data(), sk.size() * sizeof(key)); return result; } //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, hw::device &hwdev) { //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); sk[0] = copy(inSk.dest); sc_sub(sk[1].bytes, inSk.mask.bytes, a.bytes); for (i = 0; i < cols; i++) { M[i][0] = pubs[i].dest; subKeys(M[i][1], pubs[i].mask, Cout); } mgSig result = MLSAG_Gen(message, M, sk, index, rows, hwdev); memwipe(sk.data(), sk.size() * sizeof(key)); return result; } clsag proveRctCLSAGSimple(const key &message, const ctkeyV &pubs, const ctkey &inSk, const key &a, const key &Cout, unsigned int index, hw::device &hwdev) { //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); keyM M(cols, tmp); keyV P, C, C_nonzero; P.reserve(pubs.size()); C.reserve(pubs.size()); C_nonzero.reserve(pubs.size()); for (const ctkey &k: pubs) { P.push_back(k.dest); C_nonzero.push_back(k.mask); rct::key tmp; subKeys(tmp, k.mask, Cout); C.push_back(tmp); } sk[0] = copy(inSk.dest); sc_sub(sk[1].bytes, inSk.mask.bytes, a.bytes); clsag result = CLSAG_Gen(message, P, sk[0], C, sk[1], C_nonzero, Cout, index, hwdev); memwipe(sk.data(), sk.size() * sizeof(key)); return result; } //Ring-ct MG sigs //Prove: // c.f. https://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, const 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); ge_p3 Cp3; CHECK_AND_ASSERT_MES_L1(ge_frombytes_vartime(&Cp3, C.bytes) == 0, false, "point conv failed"); ge_cached Ccached; ge_p3_to_cached(&Ccached, &Cp3); ge_p1p1 p1; //create the matrix to mg sig for (i = 0; i < cols; i++) { M[i][0] = pubs[i].dest; ge_p3 p3; CHECK_AND_ASSERT_MES_L1(ge_frombytes_vartime(&p3, pubs[i].mask.bytes) == 0, false, "point conv failed"); ge_sub(&p1, &p3, &Ccached); ge_p1p1_to_p3(&p3, &p1); ge_p3_tobytes(M[i][1].bytes, &p3); } //DP(C); return MLSAG_Ver(message, M, mg, rows); } catch (...) { return false; } } bool verRctCLSAGSimple(const key &message, const clsag &sig, const ctkeyV & pubs, const key & C_offset) { try { PERF_TIMER(verRctCLSAGSimple); const size_t n = pubs.size(); // Check data CHECK_AND_ASSERT_MES(n >= 1, false, "Empty pubs"); CHECK_AND_ASSERT_MES(n == sig.s.size(), false, "Signature scalar vector is the wrong size!"); for (size_t i = 0; i < n; ++i) CHECK_AND_ASSERT_MES(sc_check(sig.s[i].bytes) == 0, false, "Bad signature scalar!"); CHECK_AND_ASSERT_MES(sc_check(sig.c1.bytes) == 0, false, "Bad signature commitment!"); CHECK_AND_ASSERT_MES(!(sig.I == rct::identity()), false, "Bad key image!"); // Cache commitment offset for efficient subtraction later ge_p3 C_offset_p3; CHECK_AND_ASSERT_MES(ge_frombytes_vartime(&C_offset_p3, C_offset.bytes) == 0, false, "point conv failed"); ge_cached C_offset_cached; ge_p3_to_cached(&C_offset_cached, &C_offset_p3); // Prepare key images key c = copy(sig.c1); key D_8 = scalarmult8(sig.D); CHECK_AND_ASSERT_MES(!(D_8 == rct::identity()), false, "Bad auxiliary key image!"); geDsmp I_precomp; geDsmp D_precomp; precomp(I_precomp.k,sig.I); precomp(D_precomp.k,D_8); // Aggregation hashes keyV mu_P_to_hash(2*n+4); // domain, I, D, P, C, C_offset keyV mu_C_to_hash(2*n+4); // domain, I, D, P, C, C_offset sc_0(mu_P_to_hash[0].bytes); memcpy(mu_P_to_hash[0].bytes,config::HASH_KEY_CLSAG_AGG_0,sizeof(config::HASH_KEY_CLSAG_AGG_0)-1); sc_0(mu_C_to_hash[0].bytes); memcpy(mu_C_to_hash[0].bytes,config::HASH_KEY_CLSAG_AGG_1,sizeof(config::HASH_KEY_CLSAG_AGG_1)-1); for (size_t i = 1; i < n+1; ++i) { mu_P_to_hash[i] = pubs[i-1].dest; mu_C_to_hash[i] = pubs[i-1].dest; } for (size_t i = n+1; i < 2*n+1; ++i) { mu_P_to_hash[i] = pubs[i-n-1].mask; mu_C_to_hash[i] = pubs[i-n-1].mask; } mu_P_to_hash[2*n+1] = sig.I; mu_P_to_hash[2*n+2] = sig.D; mu_P_to_hash[2*n+3] = C_offset; mu_C_to_hash[2*n+1] = sig.I; mu_C_to_hash[2*n+2] = sig.D; mu_C_to_hash[2*n+3] = C_offset; key mu_P, mu_C; mu_P = hash_to_scalar(mu_P_to_hash); mu_C = hash_to_scalar(mu_C_to_hash); // Set up round hash keyV c_to_hash(2*n+5); // domain, P, C, C_offset, message, L, R sc_0(c_to_hash[0].bytes); memcpy(c_to_hash[0].bytes,config::HASH_KEY_CLSAG_ROUND,sizeof(config::HASH_KEY_CLSAG_ROUND)-1); for (size_t i = 1; i < n+1; ++i) { c_to_hash[i] = pubs[i-1].dest; c_to_hash[i+n] = pubs[i-1].mask; } c_to_hash[2*n+1] = C_offset; c_to_hash[2*n+2] = message; key c_p; // = c[i]*mu_P key c_c; // = c[i]*mu_C key c_new; key L; key R; geDsmp P_precomp; geDsmp C_precomp; size_t i = 0; ge_p3 hash8_p3; geDsmp hash_precomp; ge_p3 temp_p3; ge_p1p1 temp_p1; while (i < n) { sc_0(c_new.bytes); sc_mul(c_p.bytes,mu_P.bytes,c.bytes); sc_mul(c_c.bytes,mu_C.bytes,c.bytes); // Precompute points for L/R precomp(P_precomp.k,pubs[i].dest); CHECK_AND_ASSERT_MES(ge_frombytes_vartime(&temp_p3, pubs[i].mask.bytes) == 0, false, "point conv failed"); ge_sub(&temp_p1,&temp_p3,&C_offset_cached); ge_p1p1_to_p3(&temp_p3,&temp_p1); ge_dsm_precomp(C_precomp.k,&temp_p3); // Compute L addKeys_aGbBcC(L,sig.s[i],c_p,P_precomp.k,c_c,C_precomp.k); // Compute R hash_to_p3(hash8_p3,pubs[i].dest); ge_dsm_precomp(hash_precomp.k, &hash8_p3); addKeys_aAbBcC(R,sig.s[i],hash_precomp.k,c_p,I_precomp.k,c_c,D_precomp.k); c_to_hash[2*n+3] = L; c_to_hash[2*n+4] = R; c_new = hash_to_scalar(c_to_hash); CHECK_AND_ASSERT_MES(!(c_new == rct::zero()), false, "Bad signature hash"); copy(c,c_new); i = i + 1; } sc_sub(c_new.bytes,c.bytes,sig.c1.bytes); return sc_isnonzero(c_new.bytes) == 0; } 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. https://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, const RCTConfig &rct_config, hw::device &hwdev) { const bool bulletproof = rct_config.range_proof_type != RangeProofBorromean; 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"); } CHECK_AND_ASSERT_THROW_MES(inSk.size() < 2, "genRct is not suitable for 2+ rings"); rctSig rv; rv.type = bulletproof ? RCTTypeFullBulletproof : RCTTypeFull; rv.message = message; rv.outPk.resize(destinations.size()); if (!bulletproof) 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.rangeSigs[i] = proveRange(rv.outPk[i].mask, outSk[i].mask, amounts[i]); #ifdef DBG CHECK_AND_ASSERT_THROW_MES(verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]), "verRange failed on newly created proof"); #endif } } rv.p.bulletproofs.clear(); if (bulletproof) { std::vector proof_amounts; size_t amounts_proved = 0; while (amounts_proved < amounts.size()) { size_t batch_size = 1; if (rct_config.range_proof_type == RangeProofMultiOutputBulletproof) while (batch_size * 2 + amounts_proved <= amounts.size()) batch_size *= 2; rct::keyV C, masks; std::vector batch_amounts(batch_size); for (i = 0; i < batch_size; ++i) batch_amounts[i] = amounts[i + amounts_proved]; rv.p.bulletproofs.push_back(proveRangeBulletproof_old(C, masks, batch_amounts)); #ifdef DBG CHECK_AND_ASSERT_THROW_MES(verBulletproof_old(rv.p.bulletproofs.back()), "verBulletproof failed on newly created proof"); #endif for (i = 0; i < batch_size; ++i) { rv.outPk[i + amounts_proved].mask = C[i]; outSk[i + amounts_proved].mask = masks[i]; } amounts_proved += batch_size; } } for (i = 0; i < outSk.size(); ++i) { //mask amount and mask rv.ecdhInfo[i].mask = copy(outSk[i].mask); rv.ecdhInfo[i].amount = d2h(amounts[i]); hwdev.ecdhEncode(rv.ecdhInfo[i], amount_keys[i], rv.type == RCTTypeBulletproof2 || rv.type == RCTTypeCLSAG || rv.type == RCTTypeBulletproofPlus); } //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, hwdev), rv.mixRing, inSk, outSk, rv.outPk, index, txnFeeKey,hwdev)); 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, const RCTConfig &rct_config, hw::device &hwdev) { unsigned int index; ctkeyM mixRing; ctkeyV outSk; tie(mixRing, index) = populateFromBlockchain(inPk, mixin); return genRct(message, inSk, destinations, amounts, mixRing, amount_keys, index, outSk, rct_config, hwdev); } //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, const RCTConfig &rct_config, hw::device &hwdev) { const bool bulletproof_or_plus = rct_config.range_proof_type > RangeProofBorromean; 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; if (bulletproof_or_plus) { switch (rct_config.bp_version) { case 0: case 4: rv.type = RCTTypeBulletproofPlus; break; case 3: rv.type = RCTTypeCLSAG; break; case 2: rv.type = RCTTypeBulletproof2; break; case 1: rv.type = RCTTypeBulletproof; break; default: ASSERT_MES_AND_THROW("Unsupported BP version: " << rct_config.bp_version); } } else rv.type = RCTTypeSimple; rv.message = message; rv.outPk.resize(destinations.size()); if (!bulletproof_or_plus) rv.p.rangeSigs.resize(destinations.size()); rv.ecdhInfo.resize(destinations.size()); size_t i; 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_or_plus) rv.p.rangeSigs[i] = proveRange(rv.outPk[i].mask, outSk[i].mask, outamounts[i]); #ifdef DBG if (!bulletproof_or_plus) CHECK_AND_ASSERT_THROW_MES(verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]), "verRange failed on newly created proof"); #endif } rv.p.bulletproofs.clear(); rv.p.bulletproofs_plus.clear(); if (bulletproof_or_plus) { const bool plus = is_rct_bulletproof_plus(rv.type); size_t n_amounts = outamounts.size(); size_t amounts_proved = 0; if (rct_config.range_proof_type == RangeProofPaddedBulletproof) { rct::keyV C, masks; if (hwdev.get_mode() == hw::device::TRANSACTION_CREATE_FAKE) { // use a fake bulletproof for speed if (plus) rv.p.bulletproofs_plus.push_back(make_dummy_bulletproof_plus(outamounts, C, masks)); else rv.p.bulletproofs.push_back(make_dummy_bulletproof(outamounts, C, masks)); } else { const epee::span keys{&amount_keys[0], amount_keys.size()}; if (plus) rv.p.bulletproofs_plus.push_back(proveRangeBulletproofPlus(C, masks, outamounts, keys, hwdev)); else rv.p.bulletproofs.push_back(proveRangeBulletproof(C, masks, outamounts, keys, hwdev)); #ifdef DBG if (plus) CHECK_AND_ASSERT_THROW_MES(verBulletproofPlus(rv.p.bulletproofs_plus.back()), "verBulletproofPlus failed on newly created proof"); else CHECK_AND_ASSERT_THROW_MES(verBulletproof(rv.p.bulletproofs.back()), "verBulletproof failed on newly created proof"); #endif } for (i = 0; i < outamounts.size(); ++i) { if (plus) rv.outPk[i].mask = C[i]; else rv.outPk[i].mask = rct::scalarmult8(C[i]); outSk[i].mask = masks[i]; } } else while (amounts_proved < n_amounts) { size_t batch_size = 1; if (rct_config.range_proof_type == RangeProofMultiOutputBulletproof) while (batch_size * 2 + amounts_proved <= n_amounts && batch_size * 2 <= (plus ? BULLETPROOF_PLUS_MAX_OUTPUTS : BULLETPROOF_MAX_OUTPUTS)) batch_size *= 2; rct::keyV C, masks; std::vector batch_amounts(batch_size); for (i = 0; i < batch_size; ++i) batch_amounts[i] = outamounts[i + amounts_proved]; if (hwdev.get_mode() == hw::device::TRANSACTION_CREATE_FAKE) { // use a fake bulletproof for speed if (plus) rv.p.bulletproofs_plus.push_back(make_dummy_bulletproof_plus(batch_amounts, C, masks)); else rv.p.bulletproofs.push_back(make_dummy_bulletproof(batch_amounts, C, masks)); } else { const epee::span keys{&amount_keys[amounts_proved], batch_size}; if (plus) rv.p.bulletproofs_plus.push_back(proveRangeBulletproofPlus(C, masks, batch_amounts, keys, hwdev)); else rv.p.bulletproofs.push_back(proveRangeBulletproof(C, masks, batch_amounts, keys, hwdev)); #ifdef DBG if (plus) CHECK_AND_ASSERT_THROW_MES(verBulletproofPlus(rv.p.bulletproofs_plus.back()), "verBulletproofPlus failed on newly created proof"); else CHECK_AND_ASSERT_THROW_MES(verBulletproof(rv.p.bulletproofs.back()), "verBulletproof failed on newly created proof"); #endif } for (i = 0; i < batch_size; ++i) { if (plus) rv.outPk[i + amounts_proved].mask = C[i]; else rv.outPk[i + amounts_proved].mask = rct::scalarmult8(C[i]); outSk[i + amounts_proved].mask = masks[i]; } amounts_proved += batch_size; } } key sumout = zero(); for (i = 0; i < outSk.size(); ++i) { 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]); hwdev.ecdhEncode(rv.ecdhInfo[i], amount_keys[i], rv.type == RCTTypeBulletproof2 || rv.type == RCTTypeCLSAG || rv.type == RCTTypeBulletproofPlus); } //set txn fee rv.txnFee = txnFee; // TODO: unused ?? // key txnFeeKey = scalarmultH(d2h(rv.txnFee)); rv.mixRing = mixRing; keyV &pseudoOuts = bulletproof_or_plus ? rv.p.pseudoOuts : rv.pseudoOuts; pseudoOuts.resize(inamounts.size()); if (is_rct_clsag(rv.type)) rv.p.CLSAGs.resize(inamounts.size()); else 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(pseudoOuts[i], a[i], inamounts[i]); } sc_sub(a[i].bytes, sumout.bytes, sumpouts.bytes); genC(pseudoOuts[i], a[i], inamounts[i]); DP(pseudoOuts[i]); key full_message = get_pre_mlsag_hash(rv,hwdev); for (i = 0 ; i < inamounts.size(); i++) { if (is_rct_clsag(rv.type)) { if (hwdev.get_mode() == hw::device::TRANSACTION_CREATE_FAKE) rv.p.CLSAGs[i] = make_dummy_clsag(rv.mixRing[i].size()); else rv.p.CLSAGs[i] = proveRctCLSAGSimple(full_message, rv.mixRing[i], inSk[i], a[i], pseudoOuts[i], index[i], hwdev); } else { rv.p.MGs[i] = proveRctMGSimple(full_message, rv.mixRing[i], inSk[i], a[i], pseudoOuts[i], index[i], hwdev); } } 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, const RCTConfig &rct_config, hw::device &hwdev) { 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, rct_config, hwdev); } //RCT simple //for post-rct only rctSig genRctSimple_old(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, const RCTConfig &rct_config, hw::device &hwdev) { const bool bulletproof = rct_config.range_proof_type != RangeProofBorromean; 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 = bulletproof ? RCTTypeSimpleBulletproof : 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_old(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(verBulletproof_old(rv.p.bulletproofs[i]), "verBulletproof 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]); hwdev.ecdhEncode(rv.ecdhInfo[i], amount_keys[i], rv.type == RCTTypeSimpleBulletproof); } //set txn fee rv.txnFee = txnFee; // TODO: unused ?? // key txnFeeKey = scalarmultH(d2h(rv.txnFee)); rv.mixRing = mixRing; keyV &pseudoOuts = bulletproof ? rv.p.pseudoOuts : rv.pseudoOuts; 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(pseudoOuts[i], a[i], inamounts[i]); } rv.mixRing = mixRing; sc_sub(a[i].bytes, sumout.bytes, sumpouts.bytes); genC(pseudoOuts[i], a[i], inamounts[i]); DP(pseudoOuts[i]); key full_message = get_pre_mlsag_hash(rv,hwdev); for (i = 0 ; i < inamounts.size(); i++) { rv.p.MGs[i] = proveRctMGSimple(full_message, rv.mixRing[i], inSk[i], a[i], pseudoOuts[i], index[i], hwdev); } return rv; } rctSig genRctSimple_old(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, const RCTConfig &rct_config, hw::device &hwdev) { 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_old(message, inSk, destinations, inamounts, outamounts, txnFee, mixRing, amount_keys, index, outSk, rct_config, hwdev); } //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. https://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); const bool bulletproof = is_rct_bulletproof(rv.type); CHECK_AND_ASSERT_MES(rv.type == RCTTypeFull || rv.type == RCTTypeFullBulletproof, false, "verRct called on non-full rctSig"); if (semantics) { if (rv.type == RCTTypeBulletproof) CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.rangeSigs.size(), false, "Mismatched sizes of outPk and rv.p.rangeSigs"); else 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::getInstanceForCompute(); tools::threadpool::waiter waiter(tpool); std::deque results(bulletproof ? rv.p.bulletproofs.size() : rv.outPk.size(), false); DP("range proofs verified?"); if (rct::is_rct_new_bulletproof(rv.type)) { for (size_t i = 0; i < rv.p.bulletproofs.size(); i++) tpool.submit(&waiter, [&, i] { results[i] = verBulletproof(rv.p.bulletproofs[i]); }); } else if (bulletproof) { for (size_t i = 0; i < rv.p.bulletproofs.size(); i++) tpool.submit(&waiter, [&, i] { results[i] = verBulletproof_old(rv.p.bulletproofs[i]); }); } else { for (size_t i = 0; i < rv.outPk.size(); i++) tpool.submit(&waiter, [&, i] { results[i] = verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]); }); } if (!waiter.wait()) return false; for (size_t i = 0; i < results.size(); ++i) { if (!results[i]) { LOG_PRINT_L1("Range proof verified failed for proof " << 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, hw::get_device("default"))); DP("mg sig verified?"); DP(mgVerd); if (!mgVerd) { LOG_PRINT_L1("MG signature verification failed"); return false; } } return true; } catch (const std::exception &e) { LOG_PRINT_L1("Error in verRct: " << e.what()); return false; } catch (...) { LOG_PRINT_L1("Error in verRct, but not an actual exception"); return false; } } //ver RingCT simple //assumes only post-rct style inputs (at least for max anonymity) bool verRctSemanticsSimple(const std::vector & rvv) { try { PERF_TIMER(verRctSemanticsSimple); tools::threadpool& tpool = tools::threadpool::getInstanceForCompute(); tools::threadpool::waiter waiter(tpool); std::deque results; std::vector bp_proofs; std::vector bpp_proofs; size_t max_non_bp_proofs = 0, offset = 0; for (const rctSig *rvp: rvv) { CHECK_AND_ASSERT_MES(rvp, false, "rctSig pointer is NULL"); const rctSig &rv = *rvp; CHECK_AND_ASSERT_MES(rv.type == RCTTypeSimple || rv.type == RCTTypeBulletproof || rv.type == RCTTypeBulletproof2 || rv.type == RCTTypeSimpleBulletproof || rv.type == RCTTypeCLSAG || rv.type == RCTTypeBulletproofPlus, false, "verRctSemanticsSimple called on non simple rctSig"); const bool bulletproof = is_rct_bulletproof(rv.type); const bool bulletproof_plus = is_rct_bulletproof_plus(rv.type); if (bulletproof || bulletproof_plus) { if (bulletproof_plus) CHECK_AND_ASSERT_MES(rv.outPk.size() == n_bulletproof_plus_amounts(rv.p.bulletproofs_plus), false, "Mismatched sizes of outPk and bulletproofs_plus"); else CHECK_AND_ASSERT_MES(rv.outPk.size() == n_bulletproof_amounts(rv.p.bulletproofs), false, "Mismatched sizes of outPk and bulletproofs"); if (is_rct_clsag(rv.type)) { CHECK_AND_ASSERT_MES(rv.p.MGs.empty(), false, "MGs are not empty for CLSAG"); CHECK_AND_ASSERT_MES(rv.p.pseudoOuts.size() == rv.p.CLSAGs.size(), false, "Mismatched sizes of rv.p.pseudoOuts and rv.p.CLSAGs"); } else { CHECK_AND_ASSERT_MES(rv.p.CLSAGs.empty(), false, "CLSAGs are not empty for MLSAG"); CHECK_AND_ASSERT_MES(rv.p.pseudoOuts.size() == rv.p.MGs.size(), false, "Mismatched sizes of rv.p.pseudoOuts and rv.p.MGs"); } CHECK_AND_ASSERT_MES(rv.pseudoOuts.empty(), false, "rv.pseudoOuts is not empty"); } 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.pseudoOuts.size() == rv.p.MGs.size(), false, "Mismatched sizes of rv.pseudoOuts and rv.p.MGs"); CHECK_AND_ASSERT_MES(rv.p.pseudoOuts.empty(), false, "rv.p.pseudoOuts is not empty"); } CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.ecdhInfo.size(), false, "Mismatched sizes of outPk and rv.ecdhInfo"); if (!bulletproof && !bulletproof_plus) max_non_bp_proofs += rv.p.rangeSigs.size(); } results.resize(max_non_bp_proofs); for (const rctSig *rvp: rvv) { const rctSig &rv = *rvp; const bool bulletproof = is_rct_bulletproof(rv.type); const bool bulletproof_plus = is_rct_bulletproof_plus(rv.type); const keyV &pseudoOuts = bulletproof || bulletproof_plus ? rv.p.pseudoOuts : rv.pseudoOuts; rct::keyV masks(rv.outPk.size()); for (size_t i = 0; i < rv.outPk.size(); i++) { if (bulletproof_plus) masks[i] = rct::scalarmult8(rv.outPk[i].mask); else masks[i] = rv.outPk[i].mask; } key sumOutpks = addKeys(masks); DP(sumOutpks); const key txnFeeKey = scalarmultH(d2h(rv.txnFee)); addKeys(sumOutpks, txnFeeKey, sumOutpks); key sumPseudoOuts = addKeys(pseudoOuts); DP(sumPseudoOuts); //check pseudoOuts vs Outs.. if (!equalKeys(sumPseudoOuts, sumOutpks)) { LOG_PRINT_L1("Sum check failed"); return false; } if (bulletproof_plus) { for (size_t i = 0; i < rv.p.bulletproofs_plus.size(); i++) bpp_proofs.push_back(&rv.p.bulletproofs_plus[i]); } else if (bulletproof) { for (size_t i = 0; i < rv.p.bulletproofs.size(); i++) bp_proofs.push_back(&rv.p.bulletproofs[i]); } else { for (size_t i = 0; i < rv.p.rangeSigs.size(); i++) tpool.submit(&waiter, [&, i, offset] { results[i+offset] = verRange(rv.outPk[i].mask, rv.p.rangeSigs[i]); }); offset += rv.p.rangeSigs.size(); } } if (!bpp_proofs.empty() && !verBulletproofPlus(bpp_proofs)) { LOG_PRINT_L1("Aggregate range proof verified failed"); if (!waiter.wait()) return false; return false; } if (!bp_proofs.empty() && !verBulletproof(bp_proofs)) { LOG_PRINT_L1("Aggregate range proof verified failed"); if (!waiter.wait()) return false; return false; } if (!waiter.wait()) return false; for (size_t i = 0; i < results.size(); ++i) { if (!results[i]) { LOG_PRINT_L1("Range proof verified failed for proof " << i); return false; } } return true; } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (const std::exception &e) { LOG_PRINT_L1("Error in verRctSemanticsSimple: " << e.what()); return false; } catch (...) { LOG_PRINT_L1("Error in verRctSemanticsSimple, but not an actual exception"); return false; } } bool verRctSemanticsSimple(const rctSig & rv) { return verRctSemanticsSimple(std::vector(1, &rv)); } //ver RingCT simple //assumes only post-rct style inputs (at least for max anonymity) bool verRctNonSemanticsSimple(const rctSig & rv) { try { PERF_TIMER(verRctNonSemanticsSimple); CHECK_AND_ASSERT_MES(rv.type == RCTTypeSimple || rv.type == RCTTypeBulletproof || rv.type == RCTTypeBulletproof2 || rv.type == RCTTypeSimpleBulletproof || rv.type == RCTTypeCLSAG || rv.type == RCTTypeBulletproofPlus, false, "verRctNonSemanticsSimple called on non simple rctSig"); const bool bulletproof = is_rct_bulletproof(rv.type); const bool bulletproof_plus = is_rct_bulletproof_plus(rv.type); // semantics check is early, and mixRing/MGs aren't resolved yet if (bulletproof || bulletproof_plus) CHECK_AND_ASSERT_MES(rv.p.pseudoOuts.size() == rv.mixRing.size(), false, "Mismatched sizes of rv.p.pseudoOuts and mixRing"); else 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::getInstanceForCompute(); tools::threadpool::waiter waiter(tpool); const keyV &pseudoOuts = bulletproof || bulletproof_plus ? rv.p.pseudoOuts : rv.pseudoOuts; const key message = get_pre_mlsag_hash(rv, hw::get_device("default")); results.clear(); results.resize(rv.mixRing.size()); for (size_t i = 0 ; i < rv.mixRing.size() ; i++) { tpool.submit(&waiter, [&, i] { if (is_rct_clsag(rv.type)) results[i] = verRctCLSAGSimple(message, rv.p.CLSAGs[i], rv.mixRing[i], pseudoOuts[i]); else results[i] = verRctMGSimple(message, rv.p.MGs[i], rv.mixRing[i], pseudoOuts[i]); }); } if (!waiter.wait()) return false; for (size_t i = 0; i < results.size(); ++i) { if (!results[i]) { LOG_PRINT_L1("verRctMGSimple/verRctCLSAGSimple failed for input " << i); return false; } } return true; } // we can get deep throws from ge_frombytes_vartime if input isn't valid catch (const std::exception &e) { LOG_PRINT_L1("Error in verRctNonSemanticsSimple: " << e.what()); return false; } catch (...) { LOG_PRINT_L1("Error in verRctNonSemanticsSimple, but not an actual exception"); 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. https://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, hw::device &hwdev) { CHECK_AND_ASSERT_MES(rv.type == RCTTypeFull || rv.type == RCTTypeFullBulletproof, false, "decodeRct called on non-full rctSig"); CHECK_AND_ASSERT_THROW_MES(i < rv.ecdhInfo.size(), "Bad index"); CHECK_AND_ASSERT_THROW_MES(rv.outPk.size() == rv.ecdhInfo.size(), "Mismatched sizes of rv.outPk and rv.ecdhInfo"); //mask amount and mask ecdhTuple ecdh_info = rv.ecdhInfo[i]; hwdev.ecdhDecode(ecdh_info, sk, rv.type == RCTTypeBulletproof2 || rv.type == RCTTypeCLSAG || rv.type == RCTTypeBulletproofPlus); mask = ecdh_info.mask; key amount = ecdh_info.amount; key C = rv.outPk[i].mask; if (is_rct_bulletproof_plus(rv.type)) C = scalarmult8(C); DP("C"); DP(C); key Ctmp; CHECK_AND_ASSERT_THROW_MES(sc_check(mask.bytes) == 0, "warning, bad ECDH mask"); CHECK_AND_ASSERT_THROW_MES(sc_check(amount.bytes) == 0, "warning, bad ECDH amount"); 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, hw::device &hwdev) { key mask; return decodeRct(rv, sk, i, mask, hwdev); } xmr_amount decodeRctSimple(const rctSig & rv, const key & sk, unsigned int i, key &mask, hw::device &hwdev) { CHECK_AND_ASSERT_MES(rv.type == RCTTypeSimple || rv.type == RCTTypeBulletproof || rv.type == RCTTypeBulletproof2 || rv.type == RCTTypeSimpleBulletproof || rv.type == RCTTypeCLSAG || rv.type == RCTTypeBulletproofPlus, false, "decodeRct called on non simple rctSig"); CHECK_AND_ASSERT_THROW_MES(i < rv.ecdhInfo.size(), "Bad index"); CHECK_AND_ASSERT_THROW_MES(rv.outPk.size() == rv.ecdhInfo.size(), "Mismatched sizes of rv.outPk and rv.ecdhInfo"); //mask amount and mask ecdhTuple ecdh_info = rv.ecdhInfo[i]; hwdev.ecdhDecode(ecdh_info, sk, rv.type == RCTTypeBulletproof2 || rv.type == RCTTypeCLSAG || rv.type == RCTTypeBulletproofPlus); mask = ecdh_info.mask; key amount = ecdh_info.amount; key C = rv.outPk[i].mask; if (is_rct_bulletproof_plus(rv.type)) C = scalarmult8(C); DP("C"); DP(C); key Ctmp; CHECK_AND_ASSERT_THROW_MES(sc_check(mask.bytes) == 0, "warning, bad ECDH mask"); CHECK_AND_ASSERT_THROW_MES(sc_check(amount.bytes) == 0, "warning, bad ECDH amount"); 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, hw::device &hwdev) { key mask; return decodeRctSimple(rv, sk, i, mask, hwdev); } }