1
0
Fork 0
forked from lthn/blockchain
blockchain/src/common/base58.cpp
2025-09-30 16:48:13 +01:00

259 lines
8.2 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

// Copyright (c) 2014-2018 Zano Project
// Copyright (c) 2014-2018 The Louisdor Project
// Copyright (c) 2012-2013 The Boolberry developers
// Copyright (c) 2017-2025 Lethean (https://lt.hn)
//
// Licensed under the European Union Public Licence (EUPL) version 1.2.
// You may obtain a copy of the licence at:
//
// https://joinup.ec.europa.eu/software/page/eupl/licence-eupl
//
// The EUPL is a copyleft licence that is compatible with the MIT/X11
// licence used by the original projects; the MIT terms are therefore
// considered “grandfathered” under the EUPL for this code.
//
// SPDXLicenseIdentifier: EUPL-1.2
//
#include <boost/config.hpp>
#include <boost/multiprecision/cpp_int.hpp>
#include "base58.h"
#include "crypto/hash.h"
#include "int-util.h"
#include "util.h"
#include "varint.h"
namespace tools
{
namespace base58
{
namespace
{
const char alphabet[] = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
const size_t alphabet_size = sizeof(alphabet) - 1;
const size_t encoded_block_sizes[] = {0, 2, 3, 5, 6, 7, 9, 10, 11};
const size_t full_block_size = sizeof(encoded_block_sizes) / sizeof(encoded_block_sizes[0]) - 1;
const size_t full_encoded_block_size = encoded_block_sizes[full_block_size];
const size_t addr_checksum_size = 4;
struct reverse_alphabet
{
reverse_alphabet()
{
m_data.resize(alphabet[alphabet_size - 1] - alphabet[0] + 1, -1);
for (size_t i = 0; i < alphabet_size; ++i)
{
size_t idx = static_cast<size_t>(alphabet[i] - alphabet[0]);
m_data[idx] = static_cast<int8_t>(i);
}
}
int operator()(char letter) const
{
size_t idx = static_cast<size_t>(letter - alphabet[0]);
return idx < m_data.size() ? m_data[idx] : -1;
}
static reverse_alphabet instance;
private:
std::vector<int8_t> m_data;
};
reverse_alphabet reverse_alphabet::instance;
struct decoded_block_sizes
{
decoded_block_sizes()
{
m_data.resize(encoded_block_sizes[full_block_size] + 1, -1);
for (size_t i = 0; i <= full_block_size; ++i)
{
m_data[encoded_block_sizes[i]] = static_cast<int>(i);
}
}
int operator()(size_t encoded_block_size) const
{
assert(encoded_block_size <= full_encoded_block_size);
return m_data[encoded_block_size];
}
static decoded_block_sizes instance;
private:
std::vector<int> m_data;
};
decoded_block_sizes decoded_block_sizes::instance;
uint64_t uint_8be_to_64(const uint8_t* data, size_t size)
{
assert(1 <= size && size <= sizeof(uint64_t));
uint64_t res = 0;
switch (9 - size)
{
case 1: res |= *data++; BOOST_FALLTHROUGH;
case 2: res <<= 8; res |= *data++; BOOST_FALLTHROUGH;
case 3: res <<= 8; res |= *data++; BOOST_FALLTHROUGH;
case 4: res <<= 8; res |= *data++; BOOST_FALLTHROUGH;
case 5: res <<= 8; res |= *data++; BOOST_FALLTHROUGH;
case 6: res <<= 8; res |= *data++; BOOST_FALLTHROUGH;
case 7: res <<= 8; res |= *data++; BOOST_FALLTHROUGH;
case 8: res <<= 8; res |= *data; break;
default: assert(false);
}
return res;
}
void uint_64_to_8be(uint64_t num, size_t size, uint8_t* data)
{
assert(1 <= size && size <= sizeof(uint64_t));
uint64_t num_be = SWAP64BE(num);
memcpy(data, reinterpret_cast<uint8_t*>(&num_be) + sizeof(uint64_t) - size, size);
}
void encode_block(const char* block, size_t size, char* res)
{
assert(1 <= size && size <= full_block_size);
uint64_t num = uint_8be_to_64(reinterpret_cast<const uint8_t*>(block), size);
int i = static_cast<int>(encoded_block_sizes[size]) - 1;
while (0 < num)
{
uint64_t remainder = num % alphabet_size;
num /= alphabet_size;
res[i] = alphabet[remainder];
--i;
}
}
bool decode_block(const char* block, size_t size, char* res)
{
assert(1 <= size && size <= full_encoded_block_size);
int res_size = decoded_block_sizes::instance(size);
if (res_size <= 0)
return false; // Invalid block size
uint64_t res_num = 0;
uint64_t order = 1;
for (size_t i = size - 1; i < size; --i)
{
int digit = reverse_alphabet::instance(block[i]);
if (digit < 0)
return false; // Invalid symbol
//uint64_t product_hi;
boost::multiprecision::uint128_t tmp = res_num;
tmp += boost::multiprecision::uint128_t(order) * digit;
if (tmp < res_num || tmp > std::numeric_limits<uint64_t>::max() )
return false; // Overflow
res_num = tmp.convert_to<uint64_t>();
order *= alphabet_size; // Never overflows, 58^10 < 2^64
}
if (static_cast<size_t>(res_size) < full_block_size && (UINT64_C(1) << (8 * res_size)) <= res_num)
return false; // Overflow
uint_64_to_8be(res_num, res_size, reinterpret_cast<uint8_t*>(res));
return true;
}
}
std::string encode(const std::string& data)
{
if (data.empty())
return std::string();
size_t full_block_count = data.size() / full_block_size;
size_t last_block_size = data.size() % full_block_size;
size_t res_size = full_block_count * full_encoded_block_size + encoded_block_sizes[last_block_size];
std::string res(res_size, alphabet[0]);
for (size_t i = 0; i < full_block_count; ++i)
{
encode_block(data.data() + i * full_block_size, full_block_size, &res[i * full_encoded_block_size]);
}
if (0 < last_block_size)
{
encode_block(data.data() + full_block_count * full_block_size, last_block_size, &res[full_block_count * full_encoded_block_size]);
}
return res;
}
bool decode(const std::string& enc, std::string& data)
{
if (enc.empty())
{
data.clear();
return true;
}
size_t full_block_count = enc.size() / full_encoded_block_size;
size_t last_block_size = enc.size() % full_encoded_block_size;
int last_block_decoded_size = decoded_block_sizes::instance(last_block_size);
if (last_block_decoded_size < 0)
return false; // Invalid enc length
size_t data_size = full_block_count * full_block_size + last_block_decoded_size;
data.resize(data_size, 0);
for (size_t i = 0; i < full_block_count; ++i)
{
if (!decode_block(enc.data() + i * full_encoded_block_size, full_encoded_block_size, &data[i * full_block_size]))
return false;
}
if (0 < last_block_size)
{
if (!decode_block(enc.data() + full_block_count * full_encoded_block_size, last_block_size,
&data[full_block_count * full_block_size]))
return false;
}
return true;
}
std::string encode_addr(uint64_t tag, const std::string& data)
{
std::string buf = get_varint_data(tag);
buf += data;
crypto::hash hash = crypto::cn_fast_hash(buf.data(), buf.size());
const char* hash_data = reinterpret_cast<const char*>(&hash);
buf.append(hash_data, addr_checksum_size);
return encode(buf);
}
bool decode_addr(std::string addr, uint64_t& tag, std::string& data)
{
std::string addr_data;
bool r = decode(addr, addr_data);
if (!r) return false;
if (addr_data.size() <= addr_checksum_size) return false;
std::string checksum(addr_checksum_size, '\0');
checksum = addr_data.substr(addr_data.size() - addr_checksum_size);
addr_data.resize(addr_data.size() - addr_checksum_size);
crypto::hash hash = crypto::cn_fast_hash(addr_data.data(), addr_data.size());
std::string expected_checksum(reinterpret_cast<const char*>(&hash), addr_checksum_size);
if (expected_checksum != checksum) return false;
int read = tools::read_varint(addr_data.begin(), addr_data.end(), tag);
if (read <= 0) return false;
data = addr_data.substr(read);
return true;
}
}
}