lbrycrd/src/base58.cpp
2016-03-09 10:10:36 +00:00

316 lines
9 KiB
C++

// Copyright (c) 2014-2015 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "base58.h"
#include "hash.h"
#include "uint256.h"
#include <assert.h>
#include <stdint.h>
#include <string.h>
#include <vector>
#include <string>
#include <boost/variant/apply_visitor.hpp>
#include <boost/variant/static_visitor.hpp>
/** All alphanumeric characters except for "0", "I", "O", and "l" */
static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch)
{
// Skip leading spaces.
while (*psz && isspace(*psz))
psz++;
// Skip and count leading '1's.
int zeroes = 0;
while (*psz == '1') {
zeroes++;
psz++;
}
// Allocate enough space in big-endian base256 representation.
std::vector<unsigned char> b256(strlen(psz) * 733 / 1000 + 1); // log(58) / log(256), rounded up.
// Process the characters.
while (*psz && !isspace(*psz)) {
// Decode base58 character
const char* ch = strchr(pszBase58, *psz);
if (ch == NULL)
return false;
// Apply "b256 = b256 * 58 + ch".
int carry = ch - pszBase58;
for (std::vector<unsigned char>::reverse_iterator it = b256.rbegin(); it != b256.rend(); it++) {
carry += 58 * (*it);
*it = carry % 256;
carry /= 256;
}
assert(carry == 0);
psz++;
}
// Skip trailing spaces.
while (isspace(*psz))
psz++;
if (*psz != 0)
return false;
// Skip leading zeroes in b256.
std::vector<unsigned char>::iterator it = b256.begin();
while (it != b256.end() && *it == 0)
it++;
// Copy result into output vector.
vch.reserve(zeroes + (b256.end() - it));
vch.assign(zeroes, 0x00);
while (it != b256.end())
vch.push_back(*(it++));
return true;
}
std::string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend)
{
// Skip & count leading zeroes.
int zeroes = 0;
int length = 0;
while (pbegin != pend && *pbegin == 0) {
pbegin++;
zeroes++;
}
// Allocate enough space in big-endian base58 representation.
int size = (pend - pbegin) * 138 / 100 + 1; // log(256) / log(58), rounded up.
std::vector<unsigned char> b58(size);
// Process the bytes.
while (pbegin != pend) {
int carry = *pbegin;
int i = 0;
// Apply "b58 = b58 * 256 + ch".
for (std::vector<unsigned char>::reverse_iterator it = b58.rbegin(); (carry != 0 || i < length) && (it != b58.rend()); it++, i++) {
carry += 256 * (*it);
*it = carry % 58;
carry /= 58;
}
assert(carry == 0);
length = i;
pbegin++;
}
// Skip leading zeroes in base58 result.
std::vector<unsigned char>::iterator it = b58.begin() + (size - length);
while (it != b58.end() && *it == 0)
it++;
// Translate the result into a string.
std::string str;
str.reserve(zeroes + (b58.end() - it));
str.assign(zeroes, '1');
while (it != b58.end())
str += pszBase58[*(it++)];
return str;
}
std::string EncodeBase58(const std::vector<unsigned char>& vch)
{
return EncodeBase58(&vch[0], &vch[0] + vch.size());
}
bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet)
{
return DecodeBase58(str.c_str(), vchRet);
}
std::string EncodeBase58Check(const std::vector<unsigned char>& vchIn)
{
// add 4-byte hash check to the end
std::vector<unsigned char> vch(vchIn);
uint256 hash = Hash(vch.begin(), vch.end());
vch.insert(vch.end(), (unsigned char*)&hash, (unsigned char*)&hash + 4);
return EncodeBase58(vch);
}
bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet)
{
if (!DecodeBase58(psz, vchRet) ||
(vchRet.size() < 4)) {
vchRet.clear();
return false;
}
// re-calculate the checksum, insure it matches the included 4-byte checksum
uint256 hash = Hash(vchRet.begin(), vchRet.end() - 4);
if (memcmp(&hash, &vchRet.end()[-4], 4) != 0) {
vchRet.clear();
return false;
}
vchRet.resize(vchRet.size() - 4);
return true;
}
bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet)
{
return DecodeBase58Check(str.c_str(), vchRet);
}
CBase58Data::CBase58Data()
{
vchVersion.clear();
vchData.clear();
}
void CBase58Data::SetData(const std::vector<unsigned char>& vchVersionIn, const void* pdata, size_t nSize)
{
vchVersion = vchVersionIn;
vchData.resize(nSize);
if (!vchData.empty())
memcpy(&vchData[0], pdata, nSize);
}
void CBase58Data::SetData(const std::vector<unsigned char>& vchVersionIn, const unsigned char* pbegin, const unsigned char* pend)
{
SetData(vchVersionIn, (void*)pbegin, pend - pbegin);
}
bool CBase58Data::SetString(const char* psz, unsigned int nVersionBytes)
{
std::vector<unsigned char> vchTemp;
bool rc58 = DecodeBase58Check(psz, vchTemp);
if ((!rc58) || (vchTemp.size() < nVersionBytes)) {
vchData.clear();
vchVersion.clear();
return false;
}
vchVersion.assign(vchTemp.begin(), vchTemp.begin() + nVersionBytes);
vchData.resize(vchTemp.size() - nVersionBytes);
if (!vchData.empty())
memcpy(&vchData[0], &vchTemp[nVersionBytes], vchData.size());
memory_cleanse(&vchTemp[0], vchData.size());
return true;
}
bool CBase58Data::SetString(const std::string& str)
{
return SetString(str.c_str());
}
std::string CBase58Data::ToString() const
{
std::vector<unsigned char> vch = vchVersion;
vch.insert(vch.end(), vchData.begin(), vchData.end());
return EncodeBase58Check(vch);
}
int CBase58Data::CompareTo(const CBase58Data& b58) const
{
if (vchVersion < b58.vchVersion)
return -1;
if (vchVersion > b58.vchVersion)
return 1;
if (vchData < b58.vchData)
return -1;
if (vchData > b58.vchData)
return 1;
return 0;
}
namespace
{
class CBitcoinAddressVisitor : public boost::static_visitor<bool>
{
private:
CBitcoinAddress* addr;
public:
CBitcoinAddressVisitor(CBitcoinAddress* addrIn) : addr(addrIn) {}
bool operator()(const CKeyID& id) const { return addr->Set(id); }
bool operator()(const CScriptID& id) const { return addr->Set(id); }
bool operator()(const CNoDestination& no) const { return false; }
};
} // anon namespace
bool CBitcoinAddress::Set(const CKeyID& id)
{
SetData(Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS), &id, 20);
return true;
}
bool CBitcoinAddress::Set(const CScriptID& id)
{
SetData(Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS), &id, 20);
return true;
}
bool CBitcoinAddress::Set(const CTxDestination& dest)
{
return boost::apply_visitor(CBitcoinAddressVisitor(this), dest);
}
bool CBitcoinAddress::IsValid() const
{
return IsValid(Params());
}
bool CBitcoinAddress::IsValid(const CChainParams& params) const
{
bool fCorrectSize = vchData.size() == 20;
bool fKnownVersion = vchVersion == params.Base58Prefix(CChainParams::PUBKEY_ADDRESS) ||
vchVersion == params.Base58Prefix(CChainParams::SCRIPT_ADDRESS);
return fCorrectSize && fKnownVersion;
}
CTxDestination CBitcoinAddress::Get() const
{
if (!IsValid())
return CNoDestination();
uint160 id;
memcpy(&id, &vchData[0], 20);
if (vchVersion == Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS))
return CKeyID(id);
else if (vchVersion == Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS))
return CScriptID(id);
else
return CNoDestination();
}
bool CBitcoinAddress::GetKeyID(CKeyID& keyID) const
{
if (!IsValid() || vchVersion != Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS))
return false;
uint160 id;
memcpy(&id, &vchData[0], 20);
keyID = CKeyID(id);
return true;
}
bool CBitcoinAddress::IsScript() const
{
return IsValid() && vchVersion == Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS);
}
void CBitcoinSecret::SetKey(const CKey& vchSecret)
{
assert(vchSecret.IsValid());
SetData(Params().Base58Prefix(CChainParams::SECRET_KEY), vchSecret.begin(), vchSecret.size());
if (vchSecret.IsCompressed())
vchData.push_back(1);
}
CKey CBitcoinSecret::GetKey()
{
CKey ret;
assert(vchData.size() >= 32);
ret.Set(vchData.begin(), vchData.begin() + 32, vchData.size() > 32 && vchData[32] == 1);
return ret;
}
bool CBitcoinSecret::IsValid() const
{
bool fExpectedFormat = vchData.size() == 32 || (vchData.size() == 33 && vchData[32] == 1);
bool fCorrectVersion = vchVersion == Params().Base58Prefix(CChainParams::SECRET_KEY);
return fExpectedFormat && fCorrectVersion;
}
bool CBitcoinSecret::SetString(const char* pszSecret)
{
return CBase58Data::SetString(pszSecret) && IsValid();
}
bool CBitcoinSecret::SetString(const std::string& strSecret)
{
return SetString(strSecret.c_str());
}