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crypto: parse_tpod_from_hex_string

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sowle 2021-04-27 05:18:09 +03:00
parent 1df36cb841
commit 191a89f9c8
No known key found for this signature in database
GPG key ID: C07A24B2D89D49FC
2 changed files with 57 additions and 0 deletions
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43
src/crypto/crypto-sugar.h
View file

@ -88,6 +88,49 @@ namespace crypto
return ss.str();
}
template<typename t_pod_type>
bool parse_tpod_from_hex_string(const std::string& hex_str, t_pod_type& t_pod)
{
static const int16_t char_map[256] = { // 0-9, a-f, A-F is only allowed
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x00 - 0x1F
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, // 0x20 - 0x3F
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x40 - 0x5F
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x60 - 0x7F
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x80 - 0x9F
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0xA0 - 0xBF
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0xC0 - 0xDF
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 }; // 0xE0 - 0xFF
size_t pod_size = sizeof t_pod;
uint8_t *p = reinterpret_cast<uint8_t*>(&t_pod);
if (hex_str.size() != 2 * pod_size)
return false;
for (size_t i = 0; i < pod_size; ++i)
{
int16_t hi = char_map[static_cast<uint8_t>(hex_str[2 * i])];
int16_t lo = char_map[static_cast<uint8_t>(hex_str[2 * i + 1])];
if (hi < 0 || lo < 0)
{
// invalid characters in hex_str
memset(p, 0, pod_size);
return false;
}
p[i] = static_cast<uint8_t>(hi * 16 + lo); // write byte to pod
}
return true;
}
template<typename t_pod_type>
t_pod_type parse_tpod_from_hex_string(const std::string& hex_str)
{
t_pod_type t_pod = AUTO_VAL_INIT(t_pod);
parse_tpod_from_hex_string(hex_str, t_pod);
return t_pod;
}
//
// scalar_t - holds a 256-bit scalar, normally in [0..L-1]

14
tests/functional_tests/crypto_tests.cpp
View file

@ -1385,6 +1385,20 @@ TEST(ml2s, sig_verif_performance_2)
}
TEST(crypto, hex_tools)
{
ASSERT_EQ(parse_tpod_from_hex_string<uint8_t>("00"), 0x00);
ASSERT_EQ(parse_tpod_from_hex_string<uint8_t>("01"), 0x01);
ASSERT_EQ(parse_tpod_from_hex_string<uint8_t>("f1"), 0xf1);
ASSERT_EQ(parse_tpod_from_hex_string<uint8_t>("fe"), 0xfe);
ASSERT_EQ(parse_tpod_from_hex_string<uint64_t>("efcdab8967452301"), 0x0123456789abcdef);
ASSERT_EQ(parse_tpod_from_hex_string<uint64_t>("0123456789abcdef"), 0xefcdab8967452301);
ASSERT_EQ(parse_tpod_from_hex_string<scalar_t>("ecffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff7f"), c_scalar_Pm1);
ASSERT_EQ(parse_tpod_from_hex_string<scalar_t>("792fdce229e50661d0da1c7db39dd30700000000000000000000000000000006"), c_scalar_1div8);
return true;
}
//
// test's runner
//