src/utilstrencodings.h

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2016 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 /**
   7  * Utilities for converting data from/to strings.
   8  */
   9 #ifndef BITCOIN_UTILSTRENCODINGS_H
  10 #define BITCOIN_UTILSTRENCODINGS_H
  11
  12 #include <stdint.h>
  13 #include <string>
  14 #include <vector>
  15
  16 #define BEGIN(a)            ((char*)&(a))
  17 #define END(a)              ((char*)&((&(a))[1]))
  18 #define UBEGIN(a)           ((unsigned char*)&(a))
  19 #define UEND(a)             ((unsigned char*)&((&(a))[1]))
  20 #define ARRAYLEN(array)     (sizeof(array)/sizeof((array)[0]))
  21
  22 /** Used by SanitizeString() */
  23 enum SafeChars
  24 {
  25     SAFE_CHARS_DEFAULT, //!< The full set of allowed chars
  26     SAFE_CHARS_UA_COMMENT, //!< BIP-0014 subset
  27     SAFE_CHARS_FILENAME, //!< Chars allowed in filenames
  28 };
  29
  30 /**
  31 * Remove unsafe chars. Safe chars chosen to allow simple messages/URLs/email
  32 * addresses, but avoid anything even possibly remotely dangerous like & or >
  33 * @param[in] str    The string to sanitize
  34 * @param[in] rule   The set of safe chars to choose (default: least restrictive)
  35 * @return           A new string without unsafe chars
  36 */
  37 std::string SanitizeString(const std::string& str, int rule = SAFE_CHARS_DEFAULT);
  38 std::vector<unsigned char> ParseHex(const char* psz);
  39 std::vector<unsigned char> ParseHex(const std::string& str);
  40 signed char HexDigit(char c);
  41 /* Returns true if each character in str is a hex character, and has an even
  42  * number of hex digits.*/
  43 bool IsHex(const std::string& str);
  44 /**
  45 * Return true if the string is a hex number, optionally prefixed with "0x"
  46 */
  47 bool IsHexNumber(const std::string& str);
  48 std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid = nullptr);
  49 std::string DecodeBase64(const std::string& str);
  50 std::string EncodeBase64(const unsigned char* pch, size_t len);
  51 std::string EncodeBase64(const std::string& str);
  52 std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid = nullptr);
  53 std::string DecodeBase32(const std::string& str);
  54 std::string EncodeBase32(const unsigned char* pch, size_t len);
  55 std::string EncodeBase32(const std::string& str);
  56
  57 void SplitHostPort(std::string in, int &portOut, std::string &hostOut);
  58 std::string i64tostr(int64_t n);
  59 std::string itostr(int n);
  60 int64_t atoi64(const char* psz);
  61 int64_t atoi64(const std::string& str);
  62 int atoi(const std::string& str);
  63
  64 /**
  65  * Convert string to signed 32-bit integer with strict parse error feedback.
  66  * @returns true if the entire string could be parsed as valid integer,
  67  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  68  */
  69 bool ParseInt32(const std::string& str, int32_t *out);
  70
  71 /**
  72  * Convert string to signed 64-bit integer with strict parse error feedback.
  73  * @returns true if the entire string could be parsed as valid integer,
  74  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  75  */
  76 bool ParseInt64(const std::string& str, int64_t *out);
  77
  78 /**
  79  * Convert decimal string to unsigned 32-bit integer with strict parse error feedback.
  80  * @returns true if the entire string could be parsed as valid integer,
  81  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  82  */
  83 bool ParseUInt32(const std::string& str, uint32_t *out);
  84
  85 /**
  86  * Convert decimal string to unsigned 64-bit integer with strict parse error feedback.
  87  * @returns true if the entire string could be parsed as valid integer,
  88  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  89  */
  90 bool ParseUInt64(const std::string& str, uint64_t *out);
  91
  92 /**
  93  * Convert string to double with strict parse error feedback.
  94  * @returns true if the entire string could be parsed as valid double,
  95  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  96  */
  97 bool ParseDouble(const std::string& str, double *out);
  98
  99 template<typename T>
 100 std::string HexStr(const T itbegin, const T itend, bool fSpaces=false)
 101 {
 102     std::string rv;
 103     static const char hexmap[16] = { '0', '1', '2', '3', '4', '5', '6', '7',
 104                                      '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
 105     rv.reserve((itend-itbegin)*3);
 106     for(T it = itbegin; it < itend; ++it)
 107     {
 108         unsigned char val = (unsigned char)(*it);
 109         if(fSpaces && it != itbegin)
 110             rv.push_back(' ');
 111         rv.push_back(hexmap[val>>4]);
 112         rv.push_back(hexmap[val&15]);
 113     }
 114
 115     return rv;
 116 }
 117
 118 template<typename T>
 119 inline std::string HexStr(const T& vch, bool fSpaces=false)
 120 {
 121     return HexStr(vch.begin(), vch.end(), fSpaces);
 122 }
 123
 124 /**
 125  * Format a paragraph of text to a fixed width, adding spaces for
 126  * indentation to any added line.
 127  */
 128 std::string FormatParagraph(const std::string& in, size_t width = 79, size_t indent = 0);
 129
 130 /**
 131  * Timing-attack-resistant comparison.
 132  * Takes time proportional to length
 133  * of first argument.
 134  */
 135 template <typename T>
 136 bool TimingResistantEqual(const T& a, const T& b)
 137 {
 138     if (b.size() == 0) return a.size() == 0;
 139     size_t accumulator = a.size() ^ b.size();
 140     for (size_t i = 0; i < a.size(); i++)
 141         accumulator |= a[i] ^ b[i%b.size()];
 142     return accumulator == 0;
 143 }
 144
 145 /** Parse number as fixed point according to JSON number syntax.
 146  * See http://json.org/number.gif
 147  * @returns true on success, false on error.
 148  * @note The result must be in the range (-10^18,10^18), otherwise an overflow error will trigger.
 149  */
 150 bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);
 151
 152 /** Convert from one power-of-2 number base to another. */
 153 template<int frombits, int tobits, bool pad, typename O, typename I>
 154 bool ConvertBits(O& out, I it, I end) {
 155     size_t acc = 0;
 156     size_t bits = 0;
 157     constexpr size_t maxv = (1 << tobits) - 1;
 158     constexpr size_t max_acc = (1 << (frombits + tobits - 1)) - 1;
 159     while (it != end) {
 160         acc = ((acc << frombits) | *it) & max_acc;
 161         bits += frombits;
 162         while (bits >= tobits) {
 163             bits -= tobits;
 164             out.push_back((acc >> bits) & maxv);
 165         }
 166         ++it;
 167     }
 168     if (pad) {
 169         if (bits) out.push_back((acc << (tobits - bits)) & maxv);
 170     } else if (bits >= frombits || ((acc << (tobits - bits)) & maxv)) {
 171         return false;
 172     }
 173     return true;
 174 }
 175
 176 #endif // BITCOIN_UTILSTRENCODINGS_H