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crypto tests: point_is_zero test added

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sowle 2021-12-31 06:44:26 +03:00
parent 9ea35d3a2f
commit 140f43bc5e
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3 changed files with 65 additions and 1 deletions
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2
src/crypto/crypto-sugar.h
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@ -246,7 +246,7 @@ namespace crypto
return result;
}
// genrate 0 <= x < L
// generate 0 <= x < L
void make_random()
{
unsigned char tmp[64];

1
src/currency_core/currency_format_utils_abstract.h
View file

@ -129,6 +129,7 @@ namespace currency
}
return found;
}
//---------------------------------------------------------------
inline
const txin_to_key& get_to_key_input_from_txin_v(const txin_v& in_v)
{

63
tests/functional_tests/crypto_tests.cpp
View file

@ -1740,6 +1740,69 @@ TEST(crypto, torsion_elements)
return true;
}
TEST(crypto, point_is_zero)
{
static const fe fancy_p = { -19, 33554432, -1, 33554432, -1, 33554432, -1, 33554432, -1, 33554432 }; // 2**255 - 19
static const fe fancy_p_plus_1 = { -18, 33554432, -1, 33554432, -1, 33554432, -1, 33554432, -1, 33554432 }; // 2**255 - 18
static const fe f_one = { 1 };
ASSERT_TRUE(fe_isnonzero(fancy_p) == 0);
ASSERT_TRUE(fe_isnonzero(fancy_p_plus_1) != 0);
fe f_r, f_x;
fe_frombytes(f_x, scalar_t::random().data());
fe_mul(f_r, f_x, fancy_p);
ASSERT_TRUE(fe_isnonzero(f_r) == 0);
fe_sub(f_r, fancy_p_plus_1, f_one);
ASSERT_TRUE(fe_isnonzero(f_r) == 0);
// is_zero
point_t p;
memset(&p.m_p3, 0, sizeof p.m_p3);
memcpy(&p.m_p3.X, fancy_p, sizeof p.m_p3.X); // X = 2**255-19
memcpy(&p.m_p3.Y, fancy_p_plus_1, sizeof p.m_p3.Y); // Y = 2**255-19+1
p.m_p3.Z[0] = 1;
// {P, P+1, 1, 0} == {0, 1} (the identity point)
ASSERT_TRUE(p.is_zero());
memset(&p.m_p3, 0, sizeof p.m_p3);
memcpy(&p.m_p3.X, fancy_p, sizeof p.m_p3.X); // X = 2**255-19
memcpy(&p.m_p3.Y, fancy_p_plus_1, sizeof p.m_p3.Y); // Y = 2**255-19+1
p.m_p3.Z[0] = -1;
// {P, P+1, -1, 0} == {0, -1} (not an identity point, torsion element order 2)
ASSERT_FALSE(p.is_zero());
memset(&p.m_p3, 0, sizeof p.m_p3);
p.m_p3.Y[0] = 2;
p.m_p3.Z[0] = 2;
// {0, 2, 2, 0} == {0, 1} (the identity point)
ASSERT_TRUE(p.is_zero());
// all fe 10 components must be in [-33554432, 33554432] (curve25519-20060209.pdf page 9)
// 2**0 2**26 2**51 2**77 2**102 2**128 2**153 2**179 2**204 2*230
fe a0 = { 7172245, 16777211, 922265, 8160646, 9625798, -12989394, 10843498, 6987154, 15156548, -5214544 };
fe a1 = { 7172245, -16777221, 922266, 8160646, 9625798, -12989394, 10843498, 6987154, 15156548, -5214544 };
// note, a0 == a1:
// 16777211 * 2**26 + 922265 * 2**51 = 2076757281067996545024
// -16777221 * 2**26 + 922266 * 2**51 = 2076757281067996545024
memset(&p.m_p3, 0, sizeof p.m_p3);
memcpy(&p.m_p3.Y, &a0, sizeof a0);
memcpy(&p.m_p3.Z, &a1, sizeof a1);
// {0, x, x, 0} == {0, 1, 1, 0} == {0, 1} (the identity point)
ASSERT_TRUE(p.is_zero());
return true;
}
//
// test's runner
//