diff options
Diffstat (limited to 'src/utilstrencodings.cpp')
| -rw-r--r-- | src/utilstrencodings.cpp | 166 |
1 files changed, 164 insertions, 2 deletions
diff --git a/src/utilstrencodings.cpp b/src/utilstrencodings.cpp index c15bddc6f..1f7a2cae2 100644 --- a/src/utilstrencodings.cpp +++ b/src/utilstrencodings.cpp @@ -416,12 +416,25 @@ string DecodeBase32(const string& str) return (vchRet.size() == 0) ? string() : string((const char*)&vchRet[0], vchRet.size()); } +static bool ParsePrechecks(const std::string& str) +{ + if (str.empty()) // No empty string allowed + return false; + if (str.size() >= 1 && (isspace(str[0]) || isspace(str[str.size()-1]))) // No padding allowed + return false; + if (str.size() != strlen(str.c_str())) // No embedded NUL characters allowed + return false; + return true; +} + bool ParseInt32(const std::string& str, int32_t *out) { + if (!ParsePrechecks(str)) + return false; char *endp = NULL; errno = 0; // strtol will not set errno if valid long int n = strtol(str.c_str(), &endp, 10); - if(out) *out = (int)n; + if(out) *out = (int32_t)n; // Note that strtol returns a *long int*, so even if strtol doesn't report a over/underflow // we still have to check that the returned value is within the range of an *int32_t*. On 64-bit // platforms the size of these types may be different. @@ -430,7 +443,36 @@ bool ParseInt32(const std::string& str, int32_t *out) n <= std::numeric_limits<int32_t>::max(); } -std::string FormatParagraph(const std::string in, size_t width, size_t indent) +bool ParseInt64(const std::string& str, int64_t *out) +{ + if (!ParsePrechecks(str)) + return false; + char *endp = NULL; + errno = 0; // strtoll will not set errno if valid + long long int n = strtoll(str.c_str(), &endp, 10); + if(out) *out = (int64_t)n; + // Note that strtoll returns a *long long int*, so even if strtol doesn't report a over/underflow + // we still have to check that the returned value is within the range of an *int64_t*. + return endp && *endp == 0 && !errno && + n >= std::numeric_limits<int64_t>::min() && + n <= std::numeric_limits<int64_t>::max(); +} + +bool ParseDouble(const std::string& str, double *out) +{ + if (!ParsePrechecks(str)) + return false; + if (str.size() >= 2 && str[0] == '0' && str[1] == 'x') // No hexadecimal floats allowed + return false; + std::istringstream text(str); + text.imbue(std::locale::classic()); + double result; + text >> result; + if(out) *out = result; + return text.eof() && !text.fail(); +} + +std::string FormatParagraph(const std::string& in, size_t width, size_t indent) { std::stringstream out; size_t col = 0; @@ -497,3 +539,123 @@ int atoi(const std::string& str) { return atoi(str.c_str()); } + +/** Upper bound for mantissa. + * 10^18-1 is the largest arbitrary decimal that will fit in a signed 64-bit integer. + * Larger integers cannot consist of arbitrary combinations of 0-9: + * + * 999999999999999999 1^18-1 + * 9223372036854775807 (1<<63)-1 (max int64_t) + * 9999999999999999999 1^19-1 (would overflow) + */ +static const int64_t UPPER_BOUND = 1000000000000000000LL - 1LL; + +/** Helper function for ParseFixedPoint */ +static inline bool ProcessMantissaDigit(char ch, int64_t &mantissa, int &mantissa_tzeros) +{ + if(ch == '0') + ++mantissa_tzeros; + else { + for (int i=0; i<=mantissa_tzeros; ++i) { + if (mantissa > (UPPER_BOUND / 10LL)) + return false; /* overflow */ + mantissa *= 10; + } + mantissa += ch - '0'; + mantissa_tzeros = 0; + } + return true; +} + +bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out) +{ + int64_t mantissa = 0; + int64_t exponent = 0; + int mantissa_tzeros = 0; + bool mantissa_sign = false; + bool exponent_sign = false; + int ptr = 0; + int end = val.size(); + int point_ofs = 0; + + if (ptr < end && val[ptr] == '-') { + mantissa_sign = true; + ++ptr; + } + if (ptr < end) + { + if (val[ptr] == '0') { + /* pass single 0 */ + ++ptr; + } else if (val[ptr] >= '1' && val[ptr] <= '9') { + while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') { + if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros)) + return false; /* overflow */ + ++ptr; + } + } else return false; /* missing expected digit */ + } else return false; /* empty string or loose '-' */ + if (ptr < end && val[ptr] == '.') + { + ++ptr; + if (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') + { + while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') { + if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros)) + return false; /* overflow */ + ++ptr; + ++point_ofs; + } + } else return false; /* missing expected digit */ + } + if (ptr < end && (val[ptr] == 'e' || val[ptr] == 'E')) + { + ++ptr; + if (ptr < end && val[ptr] == '+') + ++ptr; + else if (ptr < end && val[ptr] == '-') { + exponent_sign = true; + ++ptr; + } + if (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') { + while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') { + if (exponent > (UPPER_BOUND / 10LL)) + return false; /* overflow */ + exponent = exponent * 10 + val[ptr] - '0'; + ++ptr; + } + } else return false; /* missing expected digit */ + } + if (ptr != end) + return false; /* trailing garbage */ + + /* finalize exponent */ + if (exponent_sign) + exponent = -exponent; + exponent = exponent - point_ofs + mantissa_tzeros; + + /* finalize mantissa */ + if (mantissa_sign) + mantissa = -mantissa; + + /* convert to one 64-bit fixed-point value */ + exponent += decimals; + if (exponent < 0) + return false; /* cannot represent values smaller than 10^-decimals */ + if (exponent >= 18) + return false; /* cannot represent values larger than or equal to 10^(18-decimals) */ + + for (int i=0; i < exponent; ++i) { + if (mantissa > (UPPER_BOUND / 10LL) || mantissa < -(UPPER_BOUND / 10LL)) + return false; /* overflow */ + mantissa *= 10; + } + if (mantissa > UPPER_BOUND || mantissa < -UPPER_BOUND) + return false; /* overflow */ + + if (amount_out) + *amount_out = mantissa; + + return true; +} + |