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 /** This is needed because the foreach macro can't get over the comma in pair<t1, t2> */
  23 #define PAIRTYPE(t1, t2)    std::pair<t1, t2>
  24
  25 /** Used by SanitizeString() */
  26 enum SafeChars
  27 {
  28     SAFE_CHARS_DEFAULT, //!< The full set of allowed chars
  29     SAFE_CHARS_UA_COMMENT, //!< BIP-0014 subset
  30     SAFE_CHARS_FILENAME, //!< Chars allowed in filenames
  31 };
  32
  33 /**
  34 * Remove unsafe chars. Safe chars chosen to allow simple messages/URLs/email
  35 * addresses, but avoid anything even possibly remotely dangerous like & or >
  36 * @param[in] str    The string to sanitize
  37 * @param[in] rule   The set of safe chars to choose (default: least restrictive)
  38 * @return           A new string without unsafe chars
  39 */
  40 std::string SanitizeString(const std::string& str, int rule = SAFE_CHARS_DEFAULT);
  41 std::vector<unsigned char> ParseHex(const char* psz);
  42 std::vector<unsigned char> ParseHex(const std::string& str);
  43 signed char HexDigit(char c);
  44 bool IsHex(const std::string& str);
  45 std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid = NULL);
  46 std::string DecodeBase64(const std::string& str);
  47 std::string EncodeBase64(const unsigned char* pch, size_t len);
  48 std::string EncodeBase64(const std::string& str);
  49 std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid = NULL);
  50 std::string DecodeBase32(const std::string& str);
  51 std::string EncodeBase32(const unsigned char* pch, size_t len);
  52 std::string EncodeBase32(const std::string& str);
  53
  54 std::string i64tostr(int64_t n);
  55 std::string itostr(int n);
  56 int64_t atoi64(const char* psz);
  57 int64_t atoi64(const std::string& str);
  58 int atoi(const std::string& str);
  59
  60 /**
  61  * Convert string to signed 32-bit integer with strict parse error feedback.
  62  * @returns true if the entire string could be parsed as valid integer,
  63  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  64  */
  65 bool ParseInt32(const std::string& str, int32_t *out);
  66
  67 /**
  68  * Convert string to signed 64-bit integer with strict parse error feedback.
  69  * @returns true if the entire string could be parsed as valid integer,
  70  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  71  */
  72 bool ParseInt64(const std::string& str, int64_t *out);
  73
  74 /**
  75  * Convert decimal string to unsigned 32-bit integer with strict parse error feedback.
  76  * @returns true if the entire string could be parsed as valid integer,
  77  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  78  */
  79 bool ParseUInt32(const std::string& str, uint32_t *out);
  80
  81 /**
  82  * Convert decimal string to unsigned 64-bit integer with strict parse error feedback.
  83  * @returns true if the entire string could be parsed as valid integer,
  84  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  85  */
  86 bool ParseUInt64(const std::string& str, uint64_t *out);
  87
  88 /**
  89  * Convert string to double with strict parse error feedback.
  90  * @returns true if the entire string could be parsed as valid double,
  91  *   false if not the entire string could be parsed or when overflow or underflow occurred.
  92  */
  93 bool ParseDouble(const std::string& str, double *out);
  94
  95 template<typename T>
  96 std::string HexStr(const T itbegin, const T itend, bool fSpaces=false)
  97 {
  98     std::string rv;
  99     static const char hexmap[16] = { '0', '1', '2', '3', '4', '5', '6', '7',
 100                                      '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
 101     rv.reserve((itend-itbegin)*3);
 102     for(T it = itbegin; it < itend; ++it)
 103     {
 104         unsigned char val = (unsigned char)(*it);
 105         if(fSpaces && it != itbegin)
 106             rv.push_back(' ');
 107         rv.push_back(hexmap[val>>4]);
 108         rv.push_back(hexmap[val&15]);
 109     }
 110
 111     return rv;
 112 }
 113
 114 template<typename T>
 115 inline std::string HexStr(const T& vch, bool fSpaces=false)
 116 {
 117     return HexStr(vch.begin(), vch.end(), fSpaces);
 118 }
 119
 120 /**
 121  * Format a paragraph of text to a fixed width, adding spaces for
 122  * indentation to any added line.
 123  */
 124 std::string FormatParagraph(const std::string& in, size_t width = 79, size_t indent = 0);
 125
 126 /**
 127  * Timing-attack-resistant comparison.
 128  * Takes time proportional to length
 129  * of first argument.
 130  */
 131 template <typename T>
 132 bool TimingResistantEqual(const T& a, const T& b)
 133 {
 134     if (b.size() == 0) return a.size() == 0;
 135     size_t accumulator = a.size() ^ b.size();
 136     for (size_t i = 0; i < a.size(); i++)
 137         accumulator |= a[i] ^ b[i%b.size()];
 138     return accumulator == 0;
 139 }
 140
 141 /** Parse number as fixed point according to JSON number syntax.
 142  * See http://json.org/number.gif
 143  * @returns true on success, false on error.
 144  * @note The result must be in the range (-10^18,10^18), otherwise an overflow error will trigger.
 145  */
 146 bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);
 147
 148 #endif // BITCOIN_UTILSTRENCODINGS_H