src/base58.cpp

   1 // Copyright (c) 2014-2017 The Bitcoin Core developers
   2 // Distributed under the MIT software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 #include <base58.h>
   6
   7 #include <bech32.h>
   8 #include <hash.h>
   9 #include <script/script.h>
  10 #include <uint256.h>
  11 #include <utilstrencodings.h>
  12
  13 #include <boost/variant/apply_visitor.hpp>
  14 #include <boost/variant/static_visitor.hpp>
  15
  16 #include <algorithm>
  17 #include <assert.h>
  18 #include <string.h>
  19
  20
  21 /** All alphanumeric characters except for "0", "I", "O", and "l" */
  22 static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
  23
  24 bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch)
  25 {
  26     // Skip leading spaces.
  27     while (*psz && isspace(*psz))
  28         psz++;
  29     // Skip and count leading '1's.
  30     int zeroes = 0;
  31     int length = 0;
  32     while (*psz == '1') {
  33         zeroes++;
  34         psz++;
  35     }
  36     // Allocate enough space in big-endian base256 representation.
  37     int size = strlen(psz) * 733 /1000 + 1; // log(58) / log(256), rounded up.
  38     std::vector<unsigned char> b256(size);
  39     // Process the characters.
  40     while (*psz && !isspace(*psz)) {
  41         // Decode base58 character
  42         const char* ch = strchr(pszBase58, *psz);
  43         if (ch == nullptr)
  44             return false;
  45         // Apply "b256 = b256 * 58 + ch".
  46         int carry = ch - pszBase58;
  47         int i = 0;
  48         for (std::vector<unsigned char>::reverse_iterator it = b256.rbegin(); (carry != 0 || i < length) && (it != b256.rend()); ++it, ++i) {
  49             carry += 58 * (*it);
  50             *it = carry % 256;
  51             carry /= 256;
  52         }
  53         assert(carry == 0);
  54         length = i;
  55         psz++;
  56     }
  57     // Skip trailing spaces.
  58     while (isspace(*psz))
  59         psz++;
  60     if (*psz != 0)
  61         return false;
  62     // Skip leading zeroes in b256.
  63     std::vector<unsigned char>::iterator it = b256.begin() + (size - length);
  64     while (it != b256.end() && *it == 0)
  65         it++;
  66     // Copy result into output vector.
  67     vch.reserve(zeroes + (b256.end() - it));
  68     vch.assign(zeroes, 0x00);
  69     while (it != b256.end())
  70         vch.push_back(*(it++));
  71     return true;
  72 }
  73
  74 std::string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend)
  75 {
  76     // Skip & count leading zeroes.
  77     int zeroes = 0;
  78     int length = 0;
  79     while (pbegin != pend && *pbegin == 0) {
  80         pbegin++;
  81         zeroes++;
  82     }
  83     // Allocate enough space in big-endian base58 representation.
  84     int size = (pend - pbegin) * 138 / 100 + 1; // log(256) / log(58), rounded up.
  85     std::vector<unsigned char> b58(size);
  86     // Process the bytes.
  87     while (pbegin != pend) {
  88         int carry = *pbegin;
  89         int i = 0;
  90         // Apply "b58 = b58 * 256 + ch".
  91         for (std::vector<unsigned char>::reverse_iterator it = b58.rbegin(); (carry != 0 || i < length) && (it != b58.rend()); it++, i++) {
  92             carry += 256 * (*it);
  93             *it = carry % 58;
  94             carry /= 58;
  95         }
  96
  97         assert(carry == 0);
  98         length = i;
  99         pbegin++;
 100     }
 101     // Skip leading zeroes in base58 result.
 102     std::vector<unsigned char>::iterator it = b58.begin() + (size - length);
 103     while (it != b58.end() && *it == 0)
 104         it++;
 105     // Translate the result into a string.
 106     std::string str;
 107     str.reserve(zeroes + (b58.end() - it));
 108     str.assign(zeroes, '1');
 109     while (it != b58.end())
 110         str += pszBase58[*(it++)];
 111     return str;
 112 }
 113
 114 std::string EncodeBase58(const std::vector<unsigned char>& vch)
 115 {
 116     return EncodeBase58(vch.data(), vch.data() + vch.size());
 117 }
 118
 119 bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet)
 120 {
 121     return DecodeBase58(str.c_str(), vchRet);
 122 }
 123
 124 std::string EncodeBase58Check(const std::vector<unsigned char>& vchIn)
 125 {
 126     // add 4-byte hash check to the end
 127     std::vector<unsigned char> vch(vchIn);
 128     uint256 hash = Hash(vch.begin(), vch.end());
 129     vch.insert(vch.end(), (unsigned char*)&hash, (unsigned char*)&hash + 4);
 130     return EncodeBase58(vch);
 131 }
 132
 133 bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet)
 134 {
 135     if (!DecodeBase58(psz, vchRet) ||
 136         (vchRet.size() < 4)) {
 137         vchRet.clear();
 138         return false;
 139     }
 140     // re-calculate the checksum, ensure it matches the included 4-byte checksum
 141     uint256 hash = Hash(vchRet.begin(), vchRet.end() - 4);
 142     if (memcmp(&hash, &vchRet[vchRet.size() - 4], 4) != 0) {
 143         vchRet.clear();
 144         return false;
 145     }
 146     vchRet.resize(vchRet.size() - 4);
 147     return true;
 148 }
 149
 150 bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet)
 151 {
 152     return DecodeBase58Check(str.c_str(), vchRet);
 153 }
 154
 155 CBase58Data::CBase58Data()
 156 {
 157     vchVersion.clear();
 158     vchData.clear();
 159 }
 160
 161 void CBase58Data::SetData(const std::vector<unsigned char>& vchVersionIn, const void* pdata, size_t nSize)
 162 {
 163     vchVersion = vchVersionIn;
 164     vchData.resize(nSize);
 165     if (!vchData.empty())
 166         memcpy(vchData.data(), pdata, nSize);
 167 }
 168
 169 void CBase58Data::SetData(const std::vector<unsigned char>& vchVersionIn, const unsigned char* pbegin, const unsigned char* pend)
 170 {
 171     SetData(vchVersionIn, (void*)pbegin, pend - pbegin);
 172 }
 173
 174 bool CBase58Data::SetString(const char* psz, unsigned int nVersionBytes)
 175 {
 176     std::vector<unsigned char> vchTemp;
 177     bool rc58 = DecodeBase58Check(psz, vchTemp);
 178     if ((!rc58) || (vchTemp.size() < nVersionBytes)) {
 179         vchData.clear();
 180         vchVersion.clear();
 181         return false;
 182     }
 183     vchVersion.assign(vchTemp.begin(), vchTemp.begin() + nVersionBytes);
 184     vchData.resize(vchTemp.size() - nVersionBytes);
 185     if (!vchData.empty())
 186         memcpy(vchData.data(), vchTemp.data() + nVersionBytes, vchData.size());
 187     memory_cleanse(vchTemp.data(), vchTemp.size());
 188     return true;
 189 }
 190
 191 bool CBase58Data::SetString(const std::string& str)
 192 {
 193     return SetString(str.c_str());
 194 }
 195
 196 std::string CBase58Data::ToString() const
 197 {
 198     std::vector<unsigned char> vch = vchVersion;
 199     vch.insert(vch.end(), vchData.begin(), vchData.end());
 200     return EncodeBase58Check(vch);
 201 }
 202
 203 int CBase58Data::CompareTo(const CBase58Data& b58) const
 204 {
 205     if (vchVersion < b58.vchVersion)
 206         return -1;
 207     if (vchVersion > b58.vchVersion)
 208         return 1;
 209     if (vchData < b58.vchData)
 210         return -1;
 211     if (vchData > b58.vchData)
 212         return 1;
 213     return 0;
 214 }
 215
 216 namespace
 217 {
 218 class DestinationEncoder : public boost::static_visitor<std::string>
 219 {
 220 private:
 221     const CChainParams& m_params;
 222
 223 public:
 224     DestinationEncoder(const CChainParams& params) : m_params(params) {}
 225
 226     std::string operator()(const CKeyID& id) const
 227     {
 228         std::vector<unsigned char> data = m_params.Base58Prefix(CChainParams::PUBKEY_ADDRESS);
 229         data.insert(data.end(), id.begin(), id.end());
 230         return EncodeBase58Check(data);
 231     }
 232
 233     std::string operator()(const CScriptID& id) const
 234     {
 235         std::vector<unsigned char> data = m_params.Base58Prefix(CChainParams::SCRIPT_ADDRESS);
 236         data.insert(data.end(), id.begin(), id.end());
 237         return EncodeBase58Check(data);
 238     }
 239
 240     std::string operator()(const WitnessV0KeyHash& id) const
 241     {
 242         std::vector<unsigned char> data = {0};
 243         ConvertBits<8, 5, true>(data, id.begin(), id.end());
 244         return bech32::Encode(m_params.Bech32HRP(), data);
 245     }
 246
 247     std::string operator()(const WitnessV0ScriptHash& id) const
 248     {
 249         std::vector<unsigned char> data = {0};
 250         ConvertBits<8, 5, true>(data, id.begin(), id.end());
 251         return bech32::Encode(m_params.Bech32HRP(), data);
 252     }
 253
 254     std::string operator()(const WitnessUnknown& id) const
 255     {
 256         if (id.version < 1 || id.version > 16 || id.length < 2 || id.length > 40) {
 257             return {};
 258         }
 259         std::vector<unsigned char> data = {(unsigned char)id.version};
 260         ConvertBits<8, 5, true>(data, id.program, id.program + id.length);
 261         return bech32::Encode(m_params.Bech32HRP(), data);
 262     }
 263
 264     std::string operator()(const CNoDestination& no) const { return {}; }
 265 };
 266
 267 CTxDestination DecodeDestination(const std::string& str, const CChainParams& params)
 268 {
 269     std::vector<unsigned char> data;
 270     uint160 hash;
 271     if (DecodeBase58Check(str, data)) {
 272         // base58-encoded Bitcoin addresses.
 273         // Public-key-hash-addresses have version 0 (or 111 testnet).
 274         // The data vector contains RIPEMD160(SHA256(pubkey)), where pubkey is the serialized public key.
 275         const std::vector<unsigned char>& pubkey_prefix = params.Base58Prefix(CChainParams::PUBKEY_ADDRESS);
 276         if (data.size() == hash.size() + pubkey_prefix.size() && std::equal(pubkey_prefix.begin(), pubkey_prefix.end(), data.begin())) {
 277             std::copy(data.begin() + pubkey_prefix.size(), data.end(), hash.begin());
 278             return CKeyID(hash);
 279         }
 280         // Script-hash-addresses have version 5 (or 196 testnet).
 281         // The data vector contains RIPEMD160(SHA256(cscript)), where cscript is the serialized redemption script.
 282         const std::vector<unsigned char>& script_prefix = params.Base58Prefix(CChainParams::SCRIPT_ADDRESS);
 283         if (data.size() == hash.size() + script_prefix.size() && std::equal(script_prefix.begin(), script_prefix.end(), data.begin())) {
 284             std::copy(data.begin() + script_prefix.size(), data.end(), hash.begin());
 285             return CScriptID(hash);
 286         }
 287     }
 288     data.clear();
 289     auto bech = bech32::Decode(str);
 290     if (bech.second.size() > 0 && bech.first == params.Bech32HRP()) {
 291         // Bech32 decoding
 292         int version = bech.second[0]; // The first 5 bit symbol is the witness version (0-16)
 293         // The rest of the symbols are converted witness program bytes.
 294         if (ConvertBits<5, 8, false>(data, bech.second.begin() + 1, bech.second.end())) {
 295             if (version == 0) {
 296                 {
 297                     WitnessV0KeyHash keyid;
 298                     if (data.size() == keyid.size()) {
 299                         std::copy(data.begin(), data.end(), keyid.begin());
 300                         return keyid;
 301                     }
 302                 }
 303                 {
 304                     WitnessV0ScriptHash scriptid;
 305                     if (data.size() == scriptid.size()) {
 306                         std::copy(data.begin(), data.end(), scriptid.begin());
 307                         return scriptid;
 308                     }
 309                 }
 310                 return CNoDestination();
 311             }
 312             if (version > 16 || data.size() < 2 || data.size() > 40) {
 313                 return CNoDestination();
 314             }
 315             WitnessUnknown unk;
 316             unk.version = version;
 317             std::copy(data.begin(), data.end(), unk.program);
 318             unk.length = data.size();
 319             return unk;
 320         }
 321     }
 322     return CNoDestination();
 323 }
 324 } // namespace
 325
 326 void CBitcoinSecret::SetKey(const CKey& vchSecret)
 327 {
 328     assert(vchSecret.IsValid());
 329     SetData(Params().Base58Prefix(CChainParams::SECRET_KEY), vchSecret.begin(), vchSecret.size());
 330     if (vchSecret.IsCompressed())
 331         vchData.push_back(1);
 332 }
 333
 334 CKey CBitcoinSecret::GetKey()
 335 {
 336     CKey ret;
 337     assert(vchData.size() >= 32);
 338     ret.Set(vchData.begin(), vchData.begin() + 32, vchData.size() > 32 && vchData[32] == 1);
 339     return ret;
 340 }
 341
 342 bool CBitcoinSecret::IsValid() const
 343 {
 344     bool fExpectedFormat = vchData.size() == 32 || (vchData.size() == 33 && vchData[32] == 1);
 345     bool fCorrectVersion = vchVersion == Params().Base58Prefix(CChainParams::SECRET_KEY);
 346     return fExpectedFormat && fCorrectVersion;
 347 }
 348
 349 bool CBitcoinSecret::SetString(const char* pszSecret)
 350 {
 351     return CBase58Data::SetString(pszSecret) && IsValid();
 352 }
 353
 354 bool CBitcoinSecret::SetString(const std::string& strSecret)
 355 {
 356     return SetString(strSecret.c_str());
 357 }
 358
 359 std::string EncodeDestination(const CTxDestination& dest)
 360 {
 361     return boost::apply_visitor(DestinationEncoder(Params()), dest);
 362 }
 363
 364 CTxDestination DecodeDestination(const std::string& str)
 365 {
 366     return DecodeDestination(str, Params());
 367 }
 368
 369 bool IsValidDestinationString(const std::string& str, const CChainParams& params)
 370 {
 371     return IsValidDestination(DecodeDestination(str, params));
 372 }
 373
 374 bool IsValidDestinationString(const std::string& str)
 375 {
 376     return IsValidDestinationString(str, Params());
 377 }