src/base58.cpp

   1 // Copyright (c) 2014-2016 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 "hash.h"
   8 #include "uint256.h"
   9
  10 #include <assert.h>
  11 #include <stdint.h>
  12 #include <string.h>
  13 #include <vector>
  14 #include <string>
  15 #include <boost/variant/apply_visitor.hpp>
  16 #include <boost/variant/static_visitor.hpp>
  17
  18 /** All alphanumeric characters except for "0", "I", "O", and "l" */
  19 static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
  20
  21 bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch)
  22 {
  23     // Skip leading spaces.
  24     while (*psz && isspace(*psz))
  25         psz++;
  26     // Skip and count leading '1's.
  27     int zeroes = 0;
  28     int length = 0;
  29     while (*psz == '1') {
  30         zeroes++;
  31         psz++;
  32     }
  33     // Allocate enough space in big-endian base256 representation.
  34     int size = strlen(psz) * 733 /1000 + 1; // log(58) / log(256), rounded up.
  35     std::vector<unsigned char> b256(size);
  36     // Process the characters.
  37     while (*psz && !isspace(*psz)) {
  38         // Decode base58 character
  39         const char* ch = strchr(pszBase58, *psz);
  40         if (ch == NULL)
  41             return false;
  42         // Apply "b256 = b256 * 58 + ch".
  43         int carry = ch - pszBase58;
  44         int i = 0;
  45         for (std::vector<unsigned char>::reverse_iterator it = b256.rbegin(); (carry != 0 || i < length) && (it != b256.rend()); ++it, ++i) {
  46             carry += 58 * (*it);
  47             *it = carry % 256;
  48             carry /= 256;
  49         }
  50         assert(carry == 0);
  51         length = i;
  52         psz++;
  53     }
  54     // Skip trailing spaces.
  55     while (isspace(*psz))
  56         psz++;
  57     if (*psz != 0)
  58         return false;
  59     // Skip leading zeroes in b256.
  60     std::vector<unsigned char>::iterator it = b256.begin() + (size - length);
  61     while (it != b256.end() && *it == 0)
  62         it++;
  63     // Copy result into output vector.
  64     vch.reserve(zeroes + (b256.end() - it));
  65     vch.assign(zeroes, 0x00);
  66     while (it != b256.end())
  67         vch.push_back(*(it++));
  68     return true;
  69 }
  70
  71 std::string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend)
  72 {
  73     // Skip & count leading zeroes.
  74     int zeroes = 0;
  75     int length = 0;
  76     while (pbegin != pend && *pbegin == 0) {
  77         pbegin++;
  78         zeroes++;
  79     }
  80     // Allocate enough space in big-endian base58 representation.
  81     int size = (pend - pbegin) * 138 / 100 + 1; // log(256) / log(58), rounded up.
  82     std::vector<unsigned char> b58(size);
  83     // Process the bytes.
  84     while (pbegin != pend) {
  85         int carry = *pbegin;
  86         int i = 0;
  87         // Apply "b58 = b58 * 256 + ch".
  88         for (std::vector<unsigned char>::reverse_iterator it = b58.rbegin(); (carry != 0 || i < length) && (it != b58.rend()); it++, i++) {
  89             carry += 256 * (*it);
  90             *it = carry % 58;
  91             carry /= 58;
  92         }
  93
  94         assert(carry == 0);
  95         length = i;
  96         pbegin++;
  97     }
  98     // Skip leading zeroes in base58 result.
  99     std::vector<unsigned char>::iterator it = b58.begin() + (size - length);
 100     while (it != b58.end() && *it == 0)
 101         it++;
 102     // Translate the result into a string.
 103     std::string str;
 104     str.reserve(zeroes + (b58.end() - it));
 105     str.assign(zeroes, '1');
 106     while (it != b58.end())
 107         str += pszBase58[*(it++)];
 108     return str;
 109 }
 110
 111 std::string EncodeBase58(const std::vector<unsigned char>& vch)
 112 {
 113     return EncodeBase58(&vch[0], &vch[0] + vch.size());
 114 }
 115
 116 bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet)
 117 {
 118     return DecodeBase58(str.c_str(), vchRet);
 119 }
 120
 121 std::string EncodeBase58Check(const std::vector<unsigned char>& vchIn)
 122 {
 123     // add 4-byte hash check to the end
 124     std::vector<unsigned char> vch(vchIn);
 125     uint256 hash = Hash(vch.begin(), vch.end());
 126     vch.insert(vch.end(), (unsigned char*)&hash, (unsigned char*)&hash + 4);
 127     return EncodeBase58(vch);
 128 }
 129
 130 bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet)
 131 {
 132     if (!DecodeBase58(psz, vchRet) ||
 133         (vchRet.size() < 4)) {
 134         vchRet.clear();
 135         return false;
 136     }
 137     // re-calculate the checksum, ensure it matches the included 4-byte checksum
 138     uint256 hash = Hash(vchRet.begin(), vchRet.end() - 4);
 139     if (memcmp(&hash, &vchRet.end()[-4], 4) != 0) {
 140         vchRet.clear();
 141         return false;
 142     }
 143     vchRet.resize(vchRet.size() - 4);
 144     return true;
 145 }
 146
 147 bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet)
 148 {
 149     return DecodeBase58Check(str.c_str(), vchRet);
 150 }
 151
 152 CBase58Data::CBase58Data()
 153 {
 154     vchVersion.clear();
 155     vchData.clear();
 156 }
 157
 158 void CBase58Data::SetData(const std::vector<unsigned char>& vchVersionIn, const void* pdata, size_t nSize)
 159 {
 160     vchVersion = vchVersionIn;
 161     vchData.resize(nSize);
 162     if (!vchData.empty())
 163         memcpy(&vchData[0], pdata, nSize);
 164 }
 165
 166 void CBase58Data::SetData(const std::vector<unsigned char>& vchVersionIn, const unsigned char* pbegin, const unsigned char* pend)
 167 {
 168     SetData(vchVersionIn, (void*)pbegin, pend - pbegin);
 169 }
 170
 171 bool CBase58Data::SetString(const char* psz, unsigned int nVersionBytes)
 172 {
 173     std::vector<unsigned char> vchTemp;
 174     bool rc58 = DecodeBase58Check(psz, vchTemp);
 175     if ((!rc58) || (vchTemp.size() < nVersionBytes)) {
 176         vchData.clear();
 177         vchVersion.clear();
 178         return false;
 179     }
 180     vchVersion.assign(vchTemp.begin(), vchTemp.begin() + nVersionBytes);
 181     vchData.resize(vchTemp.size() - nVersionBytes);
 182     if (!vchData.empty())
 183         memcpy(&vchData[0], &vchTemp[nVersionBytes], vchData.size());
 184     memory_cleanse(&vchTemp[0], vchTemp.size());
 185     return true;
 186 }
 187
 188 bool CBase58Data::SetString(const std::string& str)
 189 {
 190     return SetString(str.c_str());
 191 }
 192
 193 std::string CBase58Data::ToString() const
 194 {
 195     std::vector<unsigned char> vch = vchVersion;
 196     vch.insert(vch.end(), vchData.begin(), vchData.end());
 197     return EncodeBase58Check(vch);
 198 }
 199
 200 int CBase58Data::CompareTo(const CBase58Data& b58) const
 201 {
 202     if (vchVersion < b58.vchVersion)
 203         return -1;
 204     if (vchVersion > b58.vchVersion)
 205         return 1;
 206     if (vchData < b58.vchData)
 207         return -1;
 208     if (vchData > b58.vchData)
 209         return 1;
 210     return 0;
 211 }
 212
 213 namespace
 214 {
 215 class CBitcoinAddressVisitor : public boost::static_visitor<bool>
 216 {
 217 private:
 218     CBitcoinAddress* addr;
 219
 220 public:
 221     CBitcoinAddressVisitor(CBitcoinAddress* addrIn) : addr(addrIn) {}
 222
 223     bool operator()(const CKeyID& id) const { return addr->Set(id); }
 224     bool operator()(const CScriptID& id) const { return addr->Set(id); }
 225     bool operator()(const CNoDestination& no) const { return false; }
 226 };
 227
 228 } // anon namespace
 229
 230 bool CBitcoinAddress::Set(const CKeyID& id)
 231 {
 232     SetData(Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS), &id, 20);
 233     return true;
 234 }
 235
 236 bool CBitcoinAddress::Set(const CScriptID& id)
 237 {
 238     SetData(Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS), &id, 20);
 239     return true;
 240 }
 241
 242 bool CBitcoinAddress::Set(const CTxDestination& dest)
 243 {
 244     return boost::apply_visitor(CBitcoinAddressVisitor(this), dest);
 245 }
 246
 247 bool CBitcoinAddress::IsValid() const
 248 {
 249     return IsValid(Params());
 250 }
 251
 252 bool CBitcoinAddress::IsValid(const CChainParams& params) const
 253 {
 254     bool fCorrectSize = vchData.size() == 20;
 255     bool fKnownVersion = vchVersion == params.Base58Prefix(CChainParams::PUBKEY_ADDRESS) ||
 256                          vchVersion == params.Base58Prefix(CChainParams::SCRIPT_ADDRESS);
 257     return fCorrectSize && fKnownVersion;
 258 }
 259
 260 CTxDestination CBitcoinAddress::Get() const
 261 {
 262     if (!IsValid())
 263         return CNoDestination();
 264     uint160 id;
 265     memcpy(&id, &vchData[0], 20);
 266     if (vchVersion == Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS))
 267         return CKeyID(id);
 268     else if (vchVersion == Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS))
 269         return CScriptID(id);
 270     else
 271         return CNoDestination();
 272 }
 273
 274 bool CBitcoinAddress::GetKeyID(CKeyID& keyID) const
 275 {
 276     if (!IsValid() || vchVersion != Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS))
 277         return false;
 278     uint160 id;
 279     memcpy(&id, &vchData[0], 20);
 280     keyID = CKeyID(id);
 281     return true;
 282 }
 283
 284 bool CBitcoinAddress::IsScript() const
 285 {
 286     return IsValid() && vchVersion == Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS);
 287 }
 288
 289 void CBitcoinSecret::SetKey(const CKey& vchSecret)
 290 {
 291     assert(vchSecret.IsValid());
 292     SetData(Params().Base58Prefix(CChainParams::SECRET_KEY), vchSecret.begin(), vchSecret.size());
 293     if (vchSecret.IsCompressed())
 294         vchData.push_back(1);
 295 }
 296
 297 CKey CBitcoinSecret::GetKey()
 298 {
 299     CKey ret;
 300     assert(vchData.size() >= 32);
 301     ret.Set(vchData.begin(), vchData.begin() + 32, vchData.size() > 32 && vchData[32] == 1);
 302     return ret;
 303 }
 304
 305 bool CBitcoinSecret::IsValid() const
 306 {
 307     bool fExpectedFormat = vchData.size() == 32 || (vchData.size() == 33 && vchData[32] == 1);
 308     bool fCorrectVersion = vchVersion == Params().Base58Prefix(CChainParams::SECRET_KEY);
 309     return fExpectedFormat && fCorrectVersion;
 310 }
 311
 312 bool CBitcoinSecret::SetString(const char* pszSecret)
 313 {
 314     return CBase58Data::SetString(pszSecret) && IsValid();
 315 }
 316
 317 bool CBitcoinSecret::SetString(const std::string& strSecret)
 318 {
 319     return SetString(strSecret.c_str());
 320 }