wownero/tests/unit_tests/ringct.cpp
moneromooo-monero 20e50ec7f7
ringct: do not serialize what can be reconstructed
The mixRing (output keys and commitments) and II fields (key images)
can be reconstructed from vin data.
This saves some modest amount of space in the tx.
2016-08-28 21:28:55 +01:00

667 lines
20 KiB
C++

// Copyright (c) 2014-2016, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
#include "gtest/gtest.h"
#include <cstdint>
#include <algorithm>
#include "ringct/rctTypes.h"
#include "ringct/rctSigs.h"
#include "ringct/rctOps.h"
using namespace crypto;
using namespace rct;
TEST(ringct, SNL)
{
key x, P1;
skpkGen(x, P1);
key P2 = pkGen();
key P3 = pkGen();
key L1, s1, s2;
GenSchnorrNonLinkable(L1, s1, s2, x, P1, P2, 0);
// a valid one
// an invalid one
ASSERT_TRUE(VerSchnorrNonLinkable(P1, P2, L1, s1, s2));
ASSERT_FALSE(VerSchnorrNonLinkable(P1, P3, L1, s1, s2));
}
TEST(ringct, ASNL)
{
int j = 0;
//Tests for ASNL
//#ASNL true one, false one, C != sum Ci, and one out of the range..
int N = 64;
key64 xv;
key64 P1v;
key64 P2v;
bits indi;
for (j = 0 ; j < N ; j++) {
indi[j] = (int)randXmrAmount(2);
xv[j] = skGen();
if ( (int)indi[j] == 0 ) {
P1v[j] = scalarmultBase(xv[j]);
P2v[j] = pkGen();
} else {
P2v[j] = scalarmultBase(xv[j]);
P1v[j] = pkGen();
}
}
//#true one
asnlSig L1s2s = GenASNL(xv, P1v, P2v, indi);
ASSERT_TRUE(VerASNL(P1v, P2v, L1s2s));
//#false one
indi[3] = (indi[3] + 1) % 2;
L1s2s = GenASNL(xv, P1v, P2v, indi);
ASSERT_FALSE(VerASNL(P1v, P2v, L1s2s));
//#true one again
indi[3] = (indi[3] + 1) % 2;
L1s2s = GenASNL(xv, P1v, P2v, indi);
ASSERT_TRUE(VerASNL(P1v, P2v, L1s2s));
//#false one
L1s2s = GenASNL(xv, P2v, P1v, indi);
ASSERT_FALSE(VerASNL(P1v, P2v, L1s2s));
}
TEST(ringct, MG_sigs)
{
int j = 0;
int N = 0;
//Tests for MG Sigs
//#MG sig: true one
N = 3;// #cols
int R = 3;// #rows
keyV xtmp = skvGen(R);
keyM xm = keyMInit(R, N);// = [[None]*N] #just used to generate test public keys
keyV sk = skvGen(R);
keyM P = keyMInit(R, N);// = keyM[[None]*N] #stores the public keys;
int ind = 2;
int i = 0;
for (j = 0 ; j < R ; j++) {
for (i = 0 ; i < N ; i++)
{
xm[i][j] = skGen();
P[i][j] = scalarmultBase(xm[i][j]);
}
}
for (j = 0 ; j < R ; j++) {
sk[j] = xm[ind][j];
}
key message = identity();
mgSig IIccss = MLSAG_Gen(message, P, sk, ind);
ASSERT_TRUE(MLSAG_Ver(message, P, IIccss, IIccss.II));
//#MG sig: false one
N = 3;// #cols
R = 3;// #rows
xtmp = skvGen(R);
keyM xx(N, xtmp);// = [[None]*N] #just used to generate test public keys
sk = skvGen(R);
//P (N, xtmp);// = keyM[[None]*N] #stores the public keys;
ind = 2;
for (j = 0 ; j < R ; j++) {
for (i = 0 ; i < N ; i++)
{
xx[i][j] = skGen();
P[i][j] = scalarmultBase(xx[i][j]);
}
sk[j] = xx[ind][j];
}
sk[2] = skGen();//asume we don't know one of the private keys..
IIccss = MLSAG_Gen(message, P, sk, ind);
ASSERT_FALSE(MLSAG_Ver(message, P, IIccss, IIccss.II));
}
TEST(ringct, range_proofs)
{
//Ring CT Stuff
//ct range proofs
ctkeyV sc, pc;
ctkey sctmp, pctmp;
//add fake input 5000
tie(sctmp, pctmp) = ctskpkGen(6000);
sc.push_back(sctmp);
pc.push_back(pctmp);
tie(sctmp, pctmp) = ctskpkGen(7000);
sc.push_back(sctmp);
pc.push_back(pctmp);
vector<xmr_amount >amounts;
//add output 500
amounts.push_back(500);
keyV destinations;
key Sk, Pk;
skpkGen(Sk, Pk);
destinations.push_back(Pk);
//add output for 12500
amounts.push_back(12500);
skpkGen(Sk, Pk);
destinations.push_back(Pk);
//compute rct data with mixin 500
rctSig s = genRct(sc, pc, destinations, amounts, 3);
//verify rct data
ASSERT_TRUE(verRct(s));
//decode received amount
ASSERT_TRUE(decodeRct(s, Sk, 1));
// Ring CT with failing MG sig part should not verify!
// Since sum of inputs != outputs
amounts[1] = 12501;
skpkGen(Sk, Pk);
destinations[1] = Pk;
//compute rct data with mixin 500
s = genRct(sc, pc, destinations, amounts, 3);
//verify rct data
ASSERT_FALSE(verRct(s));
//decode received amount
ASSERT_TRUE(decodeRct(s, Sk, 1));
}
TEST(ringct, range_proofs_with_fee)
{
//Ring CT Stuff
//ct range proofs
ctkeyV sc, pc;
ctkey sctmp, pctmp;
//add fake input 5000
tie(sctmp, pctmp) = ctskpkGen(6001);
sc.push_back(sctmp);
pc.push_back(pctmp);
tie(sctmp, pctmp) = ctskpkGen(7000);
sc.push_back(sctmp);
pc.push_back(pctmp);
vector<xmr_amount >amounts;
//add output 500
amounts.push_back(500);
keyV destinations;
key Sk, Pk;
skpkGen(Sk, Pk);
destinations.push_back(Pk);
//add txn fee for 1
//has no corresponding destination..
amounts.push_back(1);
//add output for 12500
amounts.push_back(12500);
skpkGen(Sk, Pk);
destinations.push_back(Pk);
//compute rct data with mixin 500
rctSig s = genRct(sc, pc, destinations, amounts, 3);
//verify rct data
ASSERT_TRUE(verRct(s));
//decode received amount
ASSERT_TRUE(decodeRct(s, Sk, 1));
// Ring CT with failing MG sig part should not verify!
// Since sum of inputs != outputs
amounts[1] = 12501;
skpkGen(Sk, Pk);
destinations[1] = Pk;
//compute rct data with mixin 500
s = genRct(sc, pc, destinations, amounts, 3);
//verify rct data
ASSERT_FALSE(verRct(s));
//decode received amount
ASSERT_TRUE(decodeRct(s, Sk, 1));
}
static rct::rctSig make_sample_rct_sig(int n_inputs, const uint64_t input_amounts[], int n_outputs, const uint64_t output_amounts[], bool last_is_fee)
{
ctkeyV sc, pc;
ctkey sctmp, pctmp;
vector<xmr_amount >amounts;
keyV destinations;
key Sk, Pk;
for (int n = 0; n < n_inputs; ++n) {
tie(sctmp, pctmp) = ctskpkGen(input_amounts[n]);
sc.push_back(sctmp);
pc.push_back(pctmp);
}
for (int n = 0; n < n_outputs; ++n) {
amounts.push_back(output_amounts[n]);
skpkGen(Sk, Pk);
if (n < n_outputs - 1 || !last_is_fee)
destinations.push_back(Pk);
}
return genRct(sc, pc, destinations, amounts, 3);;
}
static bool range_proof_test(bool expected_valid,
int n_inputs, const uint64_t input_amounts[], int n_outputs, const uint64_t output_amounts[], bool last_is_fee)
{
//compute rct data
bool valid;
try {
rctSig s = make_sample_rct_sig(n_inputs, input_amounts, n_outputs, output_amounts, last_is_fee);
valid = verRct(s);
}
catch (const std::exception &e) {
valid = false;
}
if (valid == expected_valid) {
return testing::AssertionSuccess();
}
else {
return testing::AssertionFailure();
}
}
#define NELTS(array) (sizeof(array)/sizeof(array[0]))
TEST(ringct, range_proofs_reject_empty_outs)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_empty_ins)
{
const uint64_t inputs[] = {};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_all_empty)
{
const uint64_t inputs[] = {};
const uint64_t outputs[] = {};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_zero_empty)
{
const uint64_t inputs[] = {0};
const uint64_t outputs[] = {};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_empty_zero)
{
const uint64_t inputs[] = {};
const uint64_t outputs[] = {0};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_zero_zero)
{
const uint64_t inputs[] = {0};
const uint64_t outputs[] = {0};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_zero_out_first)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {0, 5000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_zero_out_last)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {5000, 0};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_zero_out_middle)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {2500, 0, 2500};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_zero_in_first)
{
const uint64_t inputs[] = {0, 5000};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_zero_in_last)
{
const uint64_t inputs[] = {5000, 0};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_zero_in_middle)
{
const uint64_t inputs[] = {2500, 0, 2500};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_single_lower)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {1};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_single_higher)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {5001};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_single_out_negative)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {(uint64_t)-1000ll};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_out_negative_first)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {(uint64_t)-1000ll, 6000};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_out_negative_last)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {6000, (uint64_t)-1000ll};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_out_negative_middle)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {3000, (uint64_t)-1000ll, 3000};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_single_in_negative)
{
const uint64_t inputs[] = {(uint64_t)-1000ll};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_in_negative_first)
{
const uint64_t inputs[] = {(uint64_t)-1000ll, 6000};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_in_negative_last)
{
const uint64_t inputs[] = {6000, (uint64_t)-1000ll};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_in_negative_middle)
{
const uint64_t inputs[] = {3000, (uint64_t)-1000ll, 3000};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_reject_higher_list)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {1000, 1000, 1000, 1000, 1000, 1000};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_1_to_1)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_1_to_N)
{
const uint64_t inputs[] = {5000};
const uint64_t outputs[] = {1000, 1000, 1000, 1000, 1000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_N_to_1)
{
const uint64_t inputs[] = {1000, 1000, 1000, 1000, 1000};
const uint64_t outputs[] = {5000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_N_to_N)
{
const uint64_t inputs[] = {1000, 1000, 1000, 1000, 1000};
const uint64_t outputs[] = {1000, 1000, 1000, 1000, 1000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, range_proofs_accept_very_long)
{
const size_t N=64;
uint64_t inputs[N];
uint64_t outputs[N];
for (size_t n = 0; n < N; ++n) {
inputs[n] = n;
outputs[n] = n;
}
std::random_shuffle(inputs, inputs + N);
std::random_shuffle(outputs, outputs + N);
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false));
}
TEST(ringct, HPow2)
{
key G = scalarmultBase(d2h(1));
key H = hashToPointSimple(G);
for (int j = 0 ; j < ATOMS ; j++) {
ASSERT_TRUE(equalKeys(H, H2[j]));
addKeys(H, H, H);
}
}
static const xmr_amount test_amounts[]={0, 1, 2, 3, 4, 5, 10000, 10000000000000000000ull, 10203040506070809000ull, 123456789123456789};
TEST(ringct, ecdh_roundtrip)
{
key k, P1;
ecdhTuple t0, t1;
for (auto amount: test_amounts) {
skpkGen(k, P1);
t0.mask = skGen();
t0.amount = d2h(amount);
t1 = t0;
ecdhEncode(t1, P1);
ecdhDecode(t1, k);
ASSERT_TRUE(t0.mask == t1.mask);
ASSERT_TRUE(equalKeys(t0.mask, t1.mask));
ASSERT_TRUE(t0.amount == t1.amount);
ASSERT_TRUE(equalKeys(t0.amount, t1.amount));
}
}
TEST(ringct, d2h)
{
key k, P1;
skpkGen(k, P1);
for (auto amount: test_amounts) {
d2h(k, amount);
ASSERT_TRUE(amount == h2d(k));
}
}
TEST(ringct, d2b)
{
for (auto amount: test_amounts) {
bits b;
d2b(b, amount);
ASSERT_TRUE(amount == b2d(b));
}
}
TEST(ringct, prooveRange_is_non_deterministic)
{
key C[2], mask[2];
for (int n = 0; n < 2; ++n)
proveRange(C[n], mask[n], 80);
ASSERT_TRUE(memcmp(C[0].bytes, C[1].bytes, sizeof(C[0].bytes)));
ASSERT_TRUE(memcmp(mask[0].bytes, mask[1].bytes, sizeof(mask[0].bytes)));
}
TEST(ringct, fee_0_valid)
{
const uint64_t inputs[] = {1000, 1000};
const uint64_t outputs[] = {2000, 0};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, true));
}
TEST(ringct, fee_non_0_valid)
{
const uint64_t inputs[] = {1000, 1000};
const uint64_t outputs[] = {1900, 100};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, true));
}
TEST(ringct, fee_non_0_invalid_higher)
{
const uint64_t inputs[] = {1000, 1000};
const uint64_t outputs[] = {1990, 100};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, true));
}
TEST(ringct, fee_non_0_invalid_lower)
{
const uint64_t inputs[] = {1000, 1000};
const uint64_t outputs[] = {1000, 100};
EXPECT_TRUE(range_proof_test(false, NELTS(inputs), inputs, NELTS(outputs), outputs, true));
}
TEST(ringct, fee_burn_valid_one_out)
{
const uint64_t inputs[] = {1000, 1000};
const uint64_t outputs[] = {0, 2000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, true));
}
TEST(ringct, fee_burn_valid_zero_out)
{
const uint64_t inputs[] = {1000, 1000};
const uint64_t outputs[] = {2000};
EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, true));
}
#define TEST_rctSig_elements(name, op) \
TEST(ringct, rctSig_##name) \
{ \
const uint64_t inputs[] = {1000, 1000}; \
const uint64_t outputs[] = {1000, 1000}; \
rct::rctSig sig = make_sample_rct_sig(NELTS(inputs), inputs, NELTS(outputs), outputs, true); \
ASSERT_TRUE(rct::verRct(sig)); \
op; \
ASSERT_FALSE(rct::verRct(sig)); \
}
TEST_rctSig_elements(rangeSigs_empty, sig.rangeSigs.resize(0));
TEST_rctSig_elements(rangeSigs_too_many, sig.rangeSigs.push_back(sig.rangeSigs.back()));
TEST_rctSig_elements(rangeSigs_too_few, sig.rangeSigs.pop_back());
TEST_rctSig_elements(mgSig_ss_empty, sig.MG.ss.resize(0));
TEST_rctSig_elements(mgSig_ss_too_many, sig.MG.ss.push_back(sig.MG.ss.back()));
TEST_rctSig_elements(mgSig_ss_too_few, sig.MG.ss.pop_back());
TEST_rctSig_elements(mgSig_ss0_empty, sig.MG.ss[0].resize(0));
TEST_rctSig_elements(mgSig_ss0_too_many, sig.MG.ss[0].push_back(sig.MG.ss[0].back()));
TEST_rctSig_elements(mgSig_ss0_too_few, sig.MG.ss[0].pop_back());
TEST_rctSig_elements(mgSig_II_empty, sig.MG.II.resize(0));
TEST_rctSig_elements(mgSig_II_too_many, sig.MG.II.push_back(sig.MG.II.back()));
TEST_rctSig_elements(mgSig_II_too_few, sig.MG.II.pop_back());
TEST_rctSig_elements(mgSig_mixRing_empty, sig.mixRing.resize(0));
TEST_rctSig_elements(mgSig_mixRing_too_many, sig.mixRing.push_back(sig.mixRing.back()));
TEST_rctSig_elements(mgSig_mixRing_too_few, sig.mixRing.pop_back());
TEST_rctSig_elements(mgSig_mixRing0_empty, sig.mixRing[0].resize(0));
TEST_rctSig_elements(mgSig_mixRing0_too_many, sig.mixRing[0].push_back(sig.mixRing[0].back()));
TEST_rctSig_elements(mgSig_mixRing0_too_few, sig.mixRing[0].pop_back());
TEST_rctSig_elements(ecdhInfo_empty, sig.ecdhInfo.resize(0));
TEST_rctSig_elements(ecdhInfo_too_many, sig.ecdhInfo.push_back(sig.ecdhInfo.back()));
TEST_rctSig_elements(ecdhInfo_too_few, sig.ecdhInfo.pop_back());
TEST_rctSig_elements(outPk_empty, sig.outPk.resize(0));
TEST_rctSig_elements(outPk_too_many, sig.outPk.push_back(sig.outPk.back()));
TEST_rctSig_elements(outPk_too_few, sig.outPk.pop_back());