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#include <cybozu/test.hpp>
#include <cybozu/random_generator.hpp>
#include <mcl/fp.hpp>
#include <mcl/ecparam.hpp>
#include <mcl/elgamal.hpp>
struct TagZn;
typedef mcl::FpT<> Fp;
typedef mcl::FpT<TagZn> Zn;
typedef mcl::EcT<Fp> Ec;
typedef mcl::ElgamalT<Ec, Zn> ElgamalEc;
const mcl::EcParam& para = mcl::ecparam::secp192k1;
cybozu::RandomGenerator rg;
CYBOZU_TEST_AUTO(testEc)
{
Fp::init(para.p);
Zn::init(para.n);
Ec::init(para.a, para.b);
const Fp x0(para.gx);
const Fp y0(para.gy);
const size_t bitSize = Zn::getBitSize();
const Ec P(x0, y0);
/*
Zn = <P>
*/
ElgamalEc::PrivateKey prv;
prv.init(P, bitSize, rg);
prv.setCache(0, 60000);
const ElgamalEc::PublicKey& pub = prv.getPublicKey();
const int m1 = 12345;
const int m2 = 17655;
ElgamalEc::CipherText c1, c2;
pub.enc(c1, m1, rg);
pub.enc(c2, m2, rg);
Zn dec1, dec2;
prv.dec(dec1, c1);
prv.dec(dec2, c2);
// dec(enc) = id
CYBOZU_TEST_EQUAL(dec1, m1);
CYBOZU_TEST_EQUAL(dec2, m2);
CYBOZU_TEST_EQUAL(prv.dec(c1), m1);
CYBOZU_TEST_EQUAL(prv.dec(c2), m2);
// iostream
{
ElgamalEc::PublicKey pub2;
ElgamalEc::PrivateKey prv2;
ElgamalEc::CipherText cc1, cc2;
{
std::stringstream ss;
ss << prv;
ss >> prv2;
}
Zn d;
prv2.dec(d, c1);
CYBOZU_TEST_EQUAL(d, m1);
{
std::stringstream ss;
ss << c1;
ss >> cc1;
}
d = 0;
prv2.dec(d, cc1);
CYBOZU_TEST_EQUAL(d, m1);
{
std::stringstream ss;
ss << pub;
ss >> pub2;
}
pub2.enc(cc2, m2, rg);
prv.dec(d, cc2);
CYBOZU_TEST_EQUAL(d, m2);
}
// enc(m1) enc(m2) = enc(m1 + m2)
c1.add(c2);
prv.dec(dec1, c1);
CYBOZU_TEST_EQUAL(dec1, m1 + m2);
// enc(m1) x = enc(m1 + x)
{
const int x = 555;
pub.add(c1, x);
prv.dec(dec1, c1);
CYBOZU_TEST_EQUAL(dec1, m1 + m2 + x);
}
// rerandomize
c1 = c2;
pub.rerandomize(c1, rg);
// verify c1 != c2
CYBOZU_TEST_ASSERT(c1.c1 != c2.c1);
CYBOZU_TEST_ASSERT(c1.c2 != c2.c2);
prv.dec(dec1, c1);
// dec(c1) = dec(c2)
CYBOZU_TEST_EQUAL(dec1, m2);
// check neg
{
ElgamalEc::CipherText c;
Zn m = 1234;
pub.enc(c, m, rg);
c.neg();
Zn dec;
prv.dec(dec, c);
CYBOZU_TEST_EQUAL(dec, -m);
}
// check mul
{
ElgamalEc::CipherText c;
Zn m = 123;
int x = 111;
pub.enc(c, m, rg);
Zn dec;
prv.dec(dec, c);
c.mul(x);
prv.dec(dec, c);
m *= x;
CYBOZU_TEST_EQUAL(dec, m);
}
// check negative value
for (int i = -10; i < 10; i++) {
ElgamalEc::CipherText c;
const Zn mm = i;
pub.enc(c, mm, rg);
Zn dec;
prv.dec(dec, c, 1000);
CYBOZU_TEST_EQUAL(dec, mm);
}
// isZeroMessage
for (int m = 0; m < 10; m++) {
ElgamalEc::CipherText c0;
pub.enc(c0, m, rg);
if (m == 0) {
CYBOZU_TEST_ASSERT(prv.isZeroMessage(c0));
} else {
CYBOZU_TEST_ASSERT(!prv.isZeroMessage(c0));
}
}
// zkp
{
ElgamalEc::Zkp zkp;
ElgamalEc::CipherText c;
pub.encWithZkp(c, zkp, 0, rg);
CYBOZU_TEST_ASSERT(pub.verify(c, zkp));
zkp.s0 += 1;
CYBOZU_TEST_ASSERT(!pub.verify(c, zkp));
pub.encWithZkp(c, zkp, 1, rg);
CYBOZU_TEST_ASSERT(pub.verify(c, zkp));
zkp.s0 += 1;
CYBOZU_TEST_ASSERT(!pub.verify(c, zkp));
CYBOZU_TEST_EXCEPTION_MESSAGE(pub.encWithZkp(c, zkp, 2, rg), cybozu::Exception, "encWithZkp");
}
}
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