src/utilstrencodings.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2017 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #include <utilstrencodings.h>
   7
   8 #include <tinyformat.h>
   9
  10 #include <cstdlib>
  11 #include <cstring>
  12 #include <errno.h>
  13 #include <limits>
  14
  15 static const std::string CHARS_ALPHA_NUM = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  16
  17 static const std::string SAFE_CHARS[] =
  18 {
  19     CHARS_ALPHA_NUM + " .,;-_/:?@()", // SAFE_CHARS_DEFAULT
  20     CHARS_ALPHA_NUM + " .,;-_?@", // SAFE_CHARS_UA_COMMENT
  21     CHARS_ALPHA_NUM + ".-_", // SAFE_CHARS_FILENAME
  22 };
  23
  24 std::string SanitizeString(const std::string& str, int rule)
  25 {
  26     std::string strResult;
  27     for (std::string::size_type i = 0; i < str.size(); i++)
  28     {
  29         if (SAFE_CHARS[rule].find(str[i]) != std::string::npos)
  30             strResult.push_back(str[i]);
  31     }
  32     return strResult;
  33 }
  34
  35 const signed char p_util_hexdigit[256] =
  36 { -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  37   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  38   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  39   0,1,2,3,4,5,6,7,8,9,-1,-1,-1,-1,-1,-1,
  40   -1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  41   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  42   -1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  43   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  44   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  45   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  46   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  47   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  48   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  49   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  50   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  51   -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, };
  52
  53 signed char HexDigit(char c)
  54 {
  55     return p_util_hexdigit[(unsigned char)c];
  56 }
  57
  58 bool IsHex(const std::string& str)
  59 {
  60     for(std::string::const_iterator it(str.begin()); it != str.end(); ++it)
  61     {
  62         if (HexDigit(*it) < 0)
  63             return false;
  64     }
  65     return (str.size() > 0) && (str.size()%2 == 0);
  66 }
  67
  68 bool IsHexNumber(const std::string& str)
  69 {
  70     size_t starting_location = 0;
  71     if (str.size() > 2 && *str.begin() == '0' && *(str.begin()+1) == 'x') {
  72         starting_location = 2;
  73     }
  74     for (auto c : str.substr(starting_location)) {
  75         if (HexDigit(c) < 0) return false;
  76     }
  77     // Return false for empty string or "0x".
  78     return (str.size() > starting_location);
  79 }
  80
  81 std::vector<unsigned char> ParseHex(const char* psz)
  82 {
  83     // convert hex dump to vector
  84     std::vector<unsigned char> vch;
  85     while (true)
  86     {
  87         while (isspace(*psz))
  88             psz++;
  89         signed char c = HexDigit(*psz++);
  90         if (c == (signed char)-1)
  91             break;
  92         unsigned char n = (c << 4);
  93         c = HexDigit(*psz++);
  94         if (c == (signed char)-1)
  95             break;
  96         n |= c;
  97         vch.push_back(n);
  98     }
  99     return vch;
 100 }
 101
 102 std::vector<unsigned char> ParseHex(const std::string& str)
 103 {
 104     return ParseHex(str.c_str());
 105 }
 106
 107 void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
 108     size_t colon = in.find_last_of(':');
 109     // if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
 110     bool fHaveColon = colon != in.npos;
 111     bool fBracketed = fHaveColon && (in[0]=='[' && in[colon-1]==']'); // if there is a colon, and in[0]=='[', colon is not 0, so in[colon-1] is safe
 112     bool fMultiColon = fHaveColon && (in.find_last_of(':',colon-1) != in.npos);
 113     if (fHaveColon && (colon==0 || fBracketed || !fMultiColon)) {
 114         int32_t n;
 115         if (ParseInt32(in.substr(colon + 1), &n) && n > 0 && n < 0x10000) {
 116             in = in.substr(0, colon);
 117             portOut = n;
 118         }
 119     }
 120     if (in.size()>0 && in[0] == '[' && in[in.size()-1] == ']')
 121         hostOut = in.substr(1, in.size()-2);
 122     else
 123         hostOut = in;
 124 }
 125
 126 std::string EncodeBase64(const unsigned char* pch, size_t len)
 127 {
 128     static const char *pbase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 129
 130     std::string strRet = "";
 131     strRet.reserve((len+2)/3*4);
 132
 133     int mode=0, left=0;
 134     const unsigned char *pchEnd = pch+len;
 135
 136     while (pch<pchEnd)
 137     {
 138         int enc = *(pch++);
 139         switch (mode)
 140         {
 141             case 0: // we have no bits
 142                 strRet += pbase64[enc >> 2];
 143                 left = (enc & 3) << 4;
 144                 mode = 1;
 145                 break;
 146
 147             case 1: // we have two bits
 148                 strRet += pbase64[left | (enc >> 4)];
 149                 left = (enc & 15) << 2;
 150                 mode = 2;
 151                 break;
 152
 153             case 2: // we have four bits
 154                 strRet += pbase64[left | (enc >> 6)];
 155                 strRet += pbase64[enc & 63];
 156                 mode = 0;
 157                 break;
 158         }
 159     }
 160
 161     if (mode)
 162     {
 163         strRet += pbase64[left];
 164         strRet += '=';
 165         if (mode == 1)
 166             strRet += '=';
 167     }
 168
 169     return strRet;
 170 }
 171
 172 std::string EncodeBase64(const std::string& str)
 173 {
 174     return EncodeBase64((const unsigned char*)str.c_str(), str.size());
 175 }
 176
 177 std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid)
 178 {
 179     static const int decode64_table[256] =
 180     {
 181         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 182         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 183         -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1,
 184         -1, -1, -1, -1, -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
 185         15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28,
 186         29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
 187         49, 50, 51, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 188         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 189         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 190         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 191         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 192         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 193         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
 194     };
 195
 196     if (pfInvalid)
 197         *pfInvalid = false;
 198
 199     std::vector<unsigned char> vchRet;
 200     vchRet.reserve(strlen(p)*3/4);
 201
 202     int mode = 0;
 203     int left = 0;
 204
 205     while (1)
 206     {
 207          int dec = decode64_table[(unsigned char)*p];
 208          if (dec == -1) break;
 209          p++;
 210          switch (mode)
 211          {
 212              case 0: // we have no bits and get 6
 213                  left = dec;
 214                  mode = 1;
 215                  break;
 216
 217               case 1: // we have 6 bits and keep 4
 218                   vchRet.push_back((left<<2) | (dec>>4));
 219                   left = dec & 15;
 220                   mode = 2;
 221                   break;
 222
 223              case 2: // we have 4 bits and get 6, we keep 2
 224                  vchRet.push_back((left<<4) | (dec>>2));
 225                  left = dec & 3;
 226                  mode = 3;
 227                  break;
 228
 229              case 3: // we have 2 bits and get 6
 230                  vchRet.push_back((left<<6) | dec);
 231                  mode = 0;
 232                  break;
 233          }
 234     }
 235
 236     if (pfInvalid)
 237         switch (mode)
 238         {
 239             case 0: // 4n base64 characters processed: ok
 240                 break;
 241
 242             case 1: // 4n+1 base64 character processed: impossible
 243                 *pfInvalid = true;
 244                 break;
 245
 246             case 2: // 4n+2 base64 characters processed: require '=='
 247                 if (left || p[0] != '=' || p[1] != '=' || decode64_table[(unsigned char)p[2]] != -1)
 248                     *pfInvalid = true;
 249                 break;
 250
 251             case 3: // 4n+3 base64 characters processed: require '='
 252                 if (left || p[0] != '=' || decode64_table[(unsigned char)p[1]] != -1)
 253                     *pfInvalid = true;
 254                 break;
 255         }
 256
 257     return vchRet;
 258 }
 259
 260 std::string DecodeBase64(const std::string& str)
 261 {
 262     std::vector<unsigned char> vchRet = DecodeBase64(str.c_str());
 263     return std::string((const char*)vchRet.data(), vchRet.size());
 264 }
 265
 266 std::string EncodeBase32(const unsigned char* pch, size_t len)
 267 {
 268     static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567";
 269
 270     std::string strRet="";
 271     strRet.reserve((len+4)/5*8);
 272
 273     int mode=0, left=0;
 274     const unsigned char *pchEnd = pch+len;
 275
 276     while (pch<pchEnd)
 277     {
 278         int enc = *(pch++);
 279         switch (mode)
 280         {
 281             case 0: // we have no bits
 282                 strRet += pbase32[enc >> 3];
 283                 left = (enc & 7) << 2;
 284                 mode = 1;
 285                 break;
 286
 287             case 1: // we have three bits
 288                 strRet += pbase32[left | (enc >> 6)];
 289                 strRet += pbase32[(enc >> 1) & 31];
 290                 left = (enc & 1) << 4;
 291                 mode = 2;
 292                 break;
 293
 294             case 2: // we have one bit
 295                 strRet += pbase32[left | (enc >> 4)];
 296                 left = (enc & 15) << 1;
 297                 mode = 3;
 298                 break;
 299
 300             case 3: // we have four bits
 301                 strRet += pbase32[left | (enc >> 7)];
 302                 strRet += pbase32[(enc >> 2) & 31];
 303                 left = (enc & 3) << 3;
 304                 mode = 4;
 305                 break;
 306
 307             case 4: // we have two bits
 308                 strRet += pbase32[left | (enc >> 5)];
 309                 strRet += pbase32[enc & 31];
 310                 mode = 0;
 311         }
 312     }
 313
 314     static const int nPadding[5] = {0, 6, 4, 3, 1};
 315     if (mode)
 316     {
 317         strRet += pbase32[left];
 318         for (int n=0; n<nPadding[mode]; n++)
 319              strRet += '=';
 320     }
 321
 322     return strRet;
 323 }
 324
 325 std::string EncodeBase32(const std::string& str)
 326 {
 327     return EncodeBase32((const unsigned char*)str.c_str(), str.size());
 328 }
 329
 330 std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid)
 331 {
 332     static const int decode32_table[256] =
 333     {
 334         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 335         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 336         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, -1, -1, -1, -1,
 337         -1, -1, -1, -1, -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
 338         15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1,  0,  1,  2,
 339          3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
 340         23, 24, 25, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 341         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 342         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 343         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 344         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 345         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 346         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
 347     };
 348
 349     if (pfInvalid)
 350         *pfInvalid = false;
 351
 352     std::vector<unsigned char> vchRet;
 353     vchRet.reserve((strlen(p))*5/8);
 354
 355     int mode = 0;
 356     int left = 0;
 357
 358     while (1)
 359     {
 360          int dec = decode32_table[(unsigned char)*p];
 361          if (dec == -1) break;
 362          p++;
 363          switch (mode)
 364          {
 365              case 0: // we have no bits and get 5
 366                  left = dec;
 367                  mode = 1;
 368                  break;
 369
 370               case 1: // we have 5 bits and keep 2
 371                   vchRet.push_back((left<<3) | (dec>>2));
 372                   left = dec & 3;
 373                   mode = 2;
 374                   break;
 375
 376              case 2: // we have 2 bits and keep 7
 377                  left = left << 5 | dec;
 378                  mode = 3;
 379                  break;
 380
 381              case 3: // we have 7 bits and keep 4
 382                  vchRet.push_back((left<<1) | (dec>>4));
 383                  left = dec & 15;
 384                  mode = 4;
 385                  break;
 386
 387              case 4: // we have 4 bits, and keep 1
 388                  vchRet.push_back((left<<4) | (dec>>1));
 389                  left = dec & 1;
 390                  mode = 5;
 391                  break;
 392
 393              case 5: // we have 1 bit, and keep 6
 394                  left = left << 5 | dec;
 395                  mode = 6;
 396                  break;
 397
 398              case 6: // we have 6 bits, and keep 3
 399                  vchRet.push_back((left<<2) | (dec>>3));
 400                  left = dec & 7;
 401                  mode = 7;
 402                  break;
 403
 404              case 7: // we have 3 bits, and keep 0
 405                  vchRet.push_back((left<<5) | dec);
 406                  mode = 0;
 407                  break;
 408          }
 409     }
 410
 411     if (pfInvalid)
 412         switch (mode)
 413         {
 414             case 0: // 8n base32 characters processed: ok
 415                 break;
 416
 417             case 1: // 8n+1 base32 characters processed: impossible
 418             case 3: //   +3
 419             case 6: //   +6
 420                 *pfInvalid = true;
 421                 break;
 422
 423             case 2: // 8n+2 base32 characters processed: require '======'
 424                 if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || p[3] != '=' || p[4] != '=' || p[5] != '=' || decode32_table[(unsigned char)p[6]] != -1)
 425                     *pfInvalid = true;
 426                 break;
 427
 428             case 4: // 8n+4 base32 characters processed: require '===='
 429                 if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || p[3] != '=' || decode32_table[(unsigned char)p[4]] != -1)
 430                     *pfInvalid = true;
 431                 break;
 432
 433             case 5: // 8n+5 base32 characters processed: require '==='
 434                 if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || decode32_table[(unsigned char)p[3]] != -1)
 435                     *pfInvalid = true;
 436                 break;
 437
 438             case 7: // 8n+7 base32 characters processed: require '='
 439                 if (left || p[0] != '=' || decode32_table[(unsigned char)p[1]] != -1)
 440                     *pfInvalid = true;
 441                 break;
 442         }
 443
 444     return vchRet;
 445 }
 446
 447 std::string DecodeBase32(const std::string& str)
 448 {
 449     std::vector<unsigned char> vchRet = DecodeBase32(str.c_str());
 450     return std::string((const char*)vchRet.data(), vchRet.size());
 451 }
 452
 453 static bool ParsePrechecks(const std::string& str)
 454 {
 455     if (str.empty()) // No empty string allowed
 456         return false;
 457     if (str.size() >= 1 && (isspace(str[0]) || isspace(str[str.size()-1]))) // No padding allowed
 458         return false;
 459     if (str.size() != strlen(str.c_str())) // No embedded NUL characters allowed
 460         return false;
 461     return true;
 462 }
 463
 464 bool ParseInt32(const std::string& str, int32_t *out)
 465 {
 466     if (!ParsePrechecks(str))
 467         return false;
 468     char *endp = nullptr;
 469     errno = 0; // strtol will not set errno if valid
 470     long int n = strtol(str.c_str(), &endp, 10);
 471     if(out) *out = (int32_t)n;
 472     // Note that strtol returns a *long int*, so even if strtol doesn't report an over/underflow
 473     // we still have to check that the returned value is within the range of an *int32_t*. On 64-bit
 474     // platforms the size of these types may be different.
 475     return endp && *endp == 0 && !errno &&
 476         n >= std::numeric_limits<int32_t>::min() &&
 477         n <= std::numeric_limits<int32_t>::max();
 478 }
 479
 480 bool ParseInt64(const std::string& str, int64_t *out)
 481 {
 482     if (!ParsePrechecks(str))
 483         return false;
 484     char *endp = nullptr;
 485     errno = 0; // strtoll will not set errno if valid
 486     long long int n = strtoll(str.c_str(), &endp, 10);
 487     if(out) *out = (int64_t)n;
 488     // Note that strtoll returns a *long long int*, so even if strtol doesn't report an over/underflow
 489     // we still have to check that the returned value is within the range of an *int64_t*.
 490     return endp && *endp == 0 && !errno &&
 491         n >= std::numeric_limits<int64_t>::min() &&
 492         n <= std::numeric_limits<int64_t>::max();
 493 }
 494
 495 bool ParseUInt32(const std::string& str, uint32_t *out)
 496 {
 497     if (!ParsePrechecks(str))
 498         return false;
 499     if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoul accepts these by default if they fit in the range
 500         return false;
 501     char *endp = nullptr;
 502     errno = 0; // strtoul will not set errno if valid
 503     unsigned long int n = strtoul(str.c_str(), &endp, 10);
 504     if(out) *out = (uint32_t)n;
 505     // Note that strtoul returns a *unsigned long int*, so even if it doesn't report an over/underflow
 506     // we still have to check that the returned value is within the range of an *uint32_t*. On 64-bit
 507     // platforms the size of these types may be different.
 508     return endp && *endp == 0 && !errno &&
 509         n <= std::numeric_limits<uint32_t>::max();
 510 }
 511
 512 bool ParseUInt64(const std::string& str, uint64_t *out)
 513 {
 514     if (!ParsePrechecks(str))
 515         return false;
 516     if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoull accepts these by default if they fit in the range
 517         return false;
 518     char *endp = nullptr;
 519     errno = 0; // strtoull will not set errno if valid
 520     unsigned long long int n = strtoull(str.c_str(), &endp, 10);
 521     if(out) *out = (uint64_t)n;
 522     // Note that strtoull returns a *unsigned long long int*, so even if it doesn't report an over/underflow
 523     // we still have to check that the returned value is within the range of an *uint64_t*.
 524     return endp && *endp == 0 && !errno &&
 525         n <= std::numeric_limits<uint64_t>::max();
 526 }
 527
 528
 529 bool ParseDouble(const std::string& str, double *out)
 530 {
 531     if (!ParsePrechecks(str))
 532         return false;
 533     if (str.size() >= 2 && str[0] == '0' && str[1] == 'x') // No hexadecimal floats allowed
 534         return false;
 535     std::istringstream text(str);
 536     text.imbue(std::locale::classic());
 537     double result;
 538     text >> result;
 539     if(out) *out = result;
 540     return text.eof() && !text.fail();
 541 }
 542
 543 std::string FormatParagraph(const std::string& in, size_t width, size_t indent)
 544 {
 545     std::stringstream out;
 546     size_t ptr = 0;
 547     size_t indented = 0;
 548     while (ptr < in.size())
 549     {
 550         size_t lineend = in.find_first_of('\n', ptr);
 551         if (lineend == std::string::npos) {
 552             lineend = in.size();
 553         }
 554         const size_t linelen = lineend - ptr;
 555         const size_t rem_width = width - indented;
 556         if (linelen <= rem_width) {
 557             out << in.substr(ptr, linelen + 1);
 558             ptr = lineend + 1;
 559             indented = 0;
 560         } else {
 561             size_t finalspace = in.find_last_of(" \n", ptr + rem_width);
 562             if (finalspace == std::string::npos || finalspace < ptr) {
 563                 // No place to break; just include the entire word and move on
 564                 finalspace = in.find_first_of("\n ", ptr);
 565                 if (finalspace == std::string::npos) {
 566                     // End of the string, just add it and break
 567                     out << in.substr(ptr);
 568                     break;
 569                 }
 570             }
 571             out << in.substr(ptr, finalspace - ptr) << "\n";
 572             if (in[finalspace] == '\n') {
 573                 indented = 0;
 574             } else if (indent) {
 575                 out << std::string(indent, ' ');
 576                 indented = indent;
 577             }
 578             ptr = finalspace + 1;
 579         }
 580     }
 581     return out.str();
 582 }
 583
 584 std::string i64tostr(int64_t n)
 585 {
 586     return strprintf("%d", n);
 587 }
 588
 589 std::string itostr(int n)
 590 {
 591     return strprintf("%d", n);
 592 }
 593
 594 int64_t atoi64(const char* psz)
 595 {
 596 #ifdef _MSC_VER
 597     return _atoi64(psz);
 598 #else
 599     return strtoll(psz, nullptr, 10);
 600 #endif
 601 }
 602
 603 int64_t atoi64(const std::string& str)
 604 {
 605 #ifdef _MSC_VER
 606     return _atoi64(str.c_str());
 607 #else
 608     return strtoll(str.c_str(), nullptr, 10);
 609 #endif
 610 }
 611
 612 int atoi(const std::string& str)
 613 {
 614     return atoi(str.c_str());
 615 }
 616
 617 /** Upper bound for mantissa.
 618  * 10^18-1 is the largest arbitrary decimal that will fit in a signed 64-bit integer.
 619  * Larger integers cannot consist of arbitrary combinations of 0-9:
 620  *
 621  *   999999999999999999  1^18-1
 622  *  9223372036854775807  (1<<63)-1  (max int64_t)
 623  *  9999999999999999999  1^19-1     (would overflow)
 624  */
 625 static const int64_t UPPER_BOUND = 1000000000000000000LL - 1LL;
 626
 627 /** Helper function for ParseFixedPoint */
 628 static inline bool ProcessMantissaDigit(char ch, int64_t &mantissa, int &mantissa_tzeros)
 629 {
 630     if(ch == '0')
 631         ++mantissa_tzeros;
 632     else {
 633         for (int i=0; i<=mantissa_tzeros; ++i) {
 634             if (mantissa > (UPPER_BOUND / 10LL))
 635                 return false; /* overflow */
 636             mantissa *= 10;
 637         }
 638         mantissa += ch - '0';
 639         mantissa_tzeros = 0;
 640     }
 641     return true;
 642 }
 643
 644 bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out)
 645 {
 646     int64_t mantissa = 0;
 647     int64_t exponent = 0;
 648     int mantissa_tzeros = 0;
 649     bool mantissa_sign = false;
 650     bool exponent_sign = false;
 651     int ptr = 0;
 652     int end = val.size();
 653     int point_ofs = 0;
 654
 655     if (ptr < end && val[ptr] == '-') {
 656         mantissa_sign = true;
 657         ++ptr;
 658     }
 659     if (ptr < end)
 660     {
 661         if (val[ptr] == '0') {
 662             /* pass single 0 */
 663             ++ptr;
 664         } else if (val[ptr] >= '1' && val[ptr] <= '9') {
 665             while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
 666                 if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros))
 667                     return false; /* overflow */
 668                 ++ptr;
 669             }
 670         } else return false; /* missing expected digit */
 671     } else return false; /* empty string or loose '-' */
 672     if (ptr < end && val[ptr] == '.')
 673     {
 674         ++ptr;
 675         if (ptr < end && val[ptr] >= '0' && val[ptr] <= '9')
 676         {
 677             while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
 678                 if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros))
 679                     return false; /* overflow */
 680                 ++ptr;
 681                 ++point_ofs;
 682             }
 683         } else return false; /* missing expected digit */
 684     }
 685     if (ptr < end && (val[ptr] == 'e' || val[ptr] == 'E'))
 686     {
 687         ++ptr;
 688         if (ptr < end && val[ptr] == '+')
 689             ++ptr;
 690         else if (ptr < end && val[ptr] == '-') {
 691             exponent_sign = true;
 692             ++ptr;
 693         }
 694         if (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
 695             while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
 696                 if (exponent > (UPPER_BOUND / 10LL))
 697                     return false; /* overflow */
 698                 exponent = exponent * 10 + val[ptr] - '0';
 699                 ++ptr;
 700             }
 701         } else return false; /* missing expected digit */
 702     }
 703     if (ptr != end)
 704         return false; /* trailing garbage */
 705
 706     /* finalize exponent */
 707     if (exponent_sign)
 708         exponent = -exponent;
 709     exponent = exponent - point_ofs + mantissa_tzeros;
 710
 711     /* finalize mantissa */
 712     if (mantissa_sign)
 713         mantissa = -mantissa;
 714
 715     /* convert to one 64-bit fixed-point value */
 716     exponent += decimals;
 717     if (exponent < 0)
 718         return false; /* cannot represent values smaller than 10^-decimals */
 719     if (exponent >= 18)
 720         return false; /* cannot represent values larger than or equal to 10^(18-decimals) */
 721
 722     for (int i=0; i < exponent; ++i) {
 723         if (mantissa > (UPPER_BOUND / 10LL) || mantissa < -(UPPER_BOUND / 10LL))
 724             return false; /* overflow */
 725         mantissa *= 10;
 726     }
 727     if (mantissa > UPPER_BOUND || mantissa < -UPPER_BOUND)
 728         return false; /* overflow */
 729
 730     if (amount_out)
 731         *amount_out = mantissa;
 732
 733     return true;
 734 }
 735