lbrycrd/src/base58.h
2013-07-15 01:05:25 +02:00

419 lines
12 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2012 The Bitcoin Developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
//
// Why base-58 instead of standard base-64 encoding?
// - Don't want 0OIl characters that look the same in some fonts and
// could be used to create visually identical looking account numbers.
// - A string with non-alphanumeric characters is not as easily accepted as an account number.
// - E-mail usually won't line-break if there's no punctuation to break at.
// - Double-clicking selects the whole number as one word if it's all alphanumeric.
//
#ifndef BITCOIN_BASE58_H
#define BITCOIN_BASE58_H
#include <string>
#include <vector>
#include "chainparams.h"
#include "bignum.h"
#include "key.h"
#include "script.h"
#include "allocators.h"
static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
// Encode a byte sequence as a base58-encoded string
inline std::string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend)
{
CAutoBN_CTX pctx;
CBigNum bn58 = 58;
CBigNum bn0 = 0;
// Convert big endian data to little endian
// Extra zero at the end make sure bignum will interpret as a positive number
std::vector<unsigned char> vchTmp(pend-pbegin+1, 0);
reverse_copy(pbegin, pend, vchTmp.begin());
// Convert little endian data to bignum
CBigNum bn;
bn.setvch(vchTmp);
// Convert bignum to std::string
std::string str;
// Expected size increase from base58 conversion is approximately 137%
// use 138% to be safe
str.reserve((pend - pbegin) * 138 / 100 + 1);
CBigNum dv;
CBigNum rem;
while (bn > bn0)
{
if (!BN_div(&dv, &rem, &bn, &bn58, pctx))
throw bignum_error("EncodeBase58 : BN_div failed");
bn = dv;
unsigned int c = rem.getulong();
str += pszBase58[c];
}
// Leading zeroes encoded as base58 zeros
for (const unsigned char* p = pbegin; p < pend && *p == 0; p++)
str += pszBase58[0];
// Convert little endian std::string to big endian
reverse(str.begin(), str.end());
return str;
}
// Encode a byte vector as a base58-encoded string
inline std::string EncodeBase58(const std::vector<unsigned char>& vch)
{
return EncodeBase58(&vch[0], &vch[0] + vch.size());
}
// Decode a base58-encoded string psz into byte vector vchRet
// returns true if decoding is successful
inline bool DecodeBase58(const char* psz, std::vector<unsigned char>& vchRet)
{
CAutoBN_CTX pctx;
vchRet.clear();
CBigNum bn58 = 58;
CBigNum bn = 0;
CBigNum bnChar;
while (isspace(*psz))
psz++;
// Convert big endian string to bignum
for (const char* p = psz; *p; p++)
{
const char* p1 = strchr(pszBase58, *p);
if (p1 == NULL)
{
while (isspace(*p))
p++;
if (*p != '\0')
return false;
break;
}
bnChar.setulong(p1 - pszBase58);
if (!BN_mul(&bn, &bn, &bn58, pctx))
throw bignum_error("DecodeBase58 : BN_mul failed");
bn += bnChar;
}
// Get bignum as little endian data
std::vector<unsigned char> vchTmp = bn.getvch();
// Trim off sign byte if present
if (vchTmp.size() >= 2 && vchTmp.end()[-1] == 0 && vchTmp.end()[-2] >= 0x80)
vchTmp.erase(vchTmp.end()-1);
// Restore leading zeros
int nLeadingZeros = 0;
for (const char* p = psz; *p == pszBase58[0]; p++)
nLeadingZeros++;
vchRet.assign(nLeadingZeros + vchTmp.size(), 0);
// Convert little endian data to big endian
reverse_copy(vchTmp.begin(), vchTmp.end(), vchRet.end() - vchTmp.size());
return true;
}
// Decode a base58-encoded string str into byte vector vchRet
// returns true if decoding is successful
inline bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet)
{
return DecodeBase58(str.c_str(), vchRet);
}
// Encode a byte vector to a base58-encoded string, including checksum
inline 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);
}
// Decode a base58-encoded string psz that includes a checksum, into byte vector vchRet
// returns true if decoding is successful
inline bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet)
{
if (!DecodeBase58(psz, vchRet))
return false;
if (vchRet.size() < 4)
{
vchRet.clear();
return false;
}
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;
}
// Decode a base58-encoded string str that includes a checksum, into byte vector vchRet
// returns true if decoding is successful
inline bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet)
{
return DecodeBase58Check(str.c_str(), vchRet);
}
/** Base class for all base58-encoded data */
class CBase58Data
{
protected:
// the version byte(s)
std::vector<unsigned char> vchVersion;
// the actually encoded data
typedef std::vector<unsigned char, zero_after_free_allocator<unsigned char> > vector_uchar;
vector_uchar vchData;
CBase58Data()
{
vchVersion.clear();
vchData.clear();
}
void 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 SetData(const std::vector<unsigned char> &vchVersionIn, const unsigned char *pbegin, const unsigned char *pend)
{
SetData(vchVersionIn, (void*)pbegin, pend - pbegin);
}
public:
bool SetString(const char* psz, unsigned int nVersionBytes = 1)
{
std::vector<unsigned char> vchTemp;
DecodeBase58Check(psz, vchTemp);
if (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());
OPENSSL_cleanse(&vchTemp[0], vchData.size());
return true;
}
bool SetString(const std::string& str)
{
return SetString(str.c_str());
}
std::string ToString() const
{
std::vector<unsigned char> vch = vchVersion;
vch.insert(vch.end(), vchData.begin(), vchData.end());
return EncodeBase58Check(vch);
}
int 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;
}
bool operator==(const CBase58Data& b58) const { return CompareTo(b58) == 0; }
bool operator<=(const CBase58Data& b58) const { return CompareTo(b58) <= 0; }
bool operator>=(const CBase58Data& b58) const { return CompareTo(b58) >= 0; }
bool operator< (const CBase58Data& b58) const { return CompareTo(b58) < 0; }
bool operator> (const CBase58Data& b58) const { return CompareTo(b58) > 0; }
};
/** base58-encoded Bitcoin addresses.
* Public-key-hash-addresses have version 0 (or 111 testnet).
* The data vector contains RIPEMD160(SHA256(pubkey)), where pubkey is the serialized public key.
* Script-hash-addresses have version 5 (or 196 testnet).
* The data vector contains RIPEMD160(SHA256(cscript)), where cscript is the serialized redemption script.
*/
class CBitcoinAddress;
class CBitcoinAddressVisitor : public boost::static_visitor<bool>
{
private:
CBitcoinAddress *addr;
public:
CBitcoinAddressVisitor(CBitcoinAddress *addrIn) : addr(addrIn) { }
bool operator()(const CKeyID &id) const;
bool operator()(const CScriptID &id) const;
bool operator()(const CNoDestination &no) const;
};
class CBitcoinAddress : public CBase58Data
{
public:
bool Set(const CKeyID &id) {
SetData(Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS), &id, 20);
return true;
}
bool Set(const CScriptID &id) {
SetData(Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS), &id, 20);
return true;
}
bool Set(const CTxDestination &dest)
{
return boost::apply_visitor(CBitcoinAddressVisitor(this), dest);
}
bool IsValid() const
{
bool fCorrectSize = vchData.size() == 20;
bool fKnownVersion = vchVersion == Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS) ||
vchVersion == Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS);
return fCorrectSize && fKnownVersion;
}
CBitcoinAddress()
{
}
CBitcoinAddress(const CTxDestination &dest)
{
Set(dest);
}
CBitcoinAddress(const std::string& strAddress)
{
SetString(strAddress);
}
CBitcoinAddress(const char* pszAddress)
{
SetString(pszAddress);
}
CTxDestination 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 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 IsScript() const {
return IsValid() && vchVersion == Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS);
}
};
bool inline CBitcoinAddressVisitor::operator()(const CKeyID &id) const { return addr->Set(id); }
bool inline CBitcoinAddressVisitor::operator()(const CScriptID &id) const { return addr->Set(id); }
bool inline CBitcoinAddressVisitor::operator()(const CNoDestination &id) const { return false; }
/** A base58-encoded secret key */
class CBitcoinSecret : public CBase58Data
{
public:
void 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 GetKey()
{
CKey ret;
ret.Set(&vchData[0], &vchData[32], vchData.size() > 32 && vchData[32] == 1);
return ret;
}
bool 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 SetString(const char* pszSecret)
{
return CBase58Data::SetString(pszSecret) && IsValid();
}
bool SetString(const std::string& strSecret)
{
return SetString(strSecret.c_str());
}
CBitcoinSecret(const CKey& vchSecret)
{
SetKey(vchSecret);
}
CBitcoinSecret()
{
}
};
template<typename K, int Size, CChainParams::Base58Type Type> class CBitcoinExtKeyBase : public CBase58Data
{
public:
void SetKey(const K &key) {
unsigned char vch[Size];
key.Encode(vch);
SetData(Params().Base58Prefix(Type), vch, vch+Size);
}
K GetKey() {
K ret;
ret.Decode(&vchData[0], &vchData[Size]);
return ret;
}
CBitcoinExtKeyBase(const K &key) {
SetKey(key);
}
CBitcoinExtKeyBase() {}
};
typedef CBitcoinExtKeyBase<CExtKey, 74, CChainParams::EXT_SECRET_KEY> CBitcoinExtKey;
typedef CBitcoinExtKeyBase<CExtPubKey, 74, CChainParams::EXT_PUBLIC_KEY> CBitcoinExtPubKey;
#endif // BITCOIN_BASE58_H