utilstrencodings.cpp

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2017 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "utilstrencodings.h"

#include "tinyformat.h"

#include <cstdlib>
#include <cstring>
#include <errno.h>
#include <limits>

static const std::string CHARS_ALPHA_NUM = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

static const std::string SAFE_CHARS[] =
{
	CHARS_ALPHA_NUM + " .,;-_/:?@()", // SAFE_CHARS_DEFAULT
	CHARS_ALPHA_NUM + " .,;-_?@", // SAFE_CHARS_UA_COMMENT
	CHARS_ALPHA_NUM + ".-_", // SAFE_CHARS_FILENAME
};

std::string SanitizeString(const std::string& str, int rule)
{
	std::string strResult;
	for (std::string::size_type i = 0; i < str.size(); i++)
	{
		if (SAFE_CHARS[rule].find(str[i]) != std::string::npos)
			strResult.push_back(str[i]);
	}
	return strResult;
}

const signed char p_util_hexdigit[256] =
{ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
0,1,2,3,4,5,6,7,8,9,-1,-1,-1,-1,-1,-1,
-1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, };

signed char HexDigit(char c)
{
	return p_util_hexdigit[(unsigned char)c];
}

bool IsHex(const std::string& str)
{
	for (std::string::const_iterator it(str.begin()); it != str.end(); ++it)
	{
		if (HexDigit(*it) < 0)
			return false;
	}
	return (str.size() > 0) && (str.size() % 2 == 0);
}

bool IsHexNumber(const std::string& str)
{
	size_t starting_location = 0;
	if (str.size() > 2 && *str.begin() == '0' && *(str.begin() + 1) == 'x') {
		starting_location = 2;
	}
	for (auto c : str.substr(starting_location)) {
		if (HexDigit(c) < 0) return false;
	}
	// Return false for empty string or "0x".
	return (str.size() > starting_location);
}

std::vector<unsigned char> ParseHex(const char* psz)
{
	// convert hex dump to vector
	std::vector<unsigned char> vch;
	while (true)
	{
		while (isspace(*psz))
			psz++;
		signed char c = HexDigit(*psz++);
		if (c == (signed char)-1)
			break;
		unsigned char n = (c << 4);
		c = HexDigit(*psz++);
		if (c == (signed char)-1)
			break;
		n |= c;
		vch.push_back(n);
	}
	return vch;
}

std::vector<unsigned char> ParseHex(const std::string& str)
{
	return ParseHex(str.c_str());
}

void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
	size_t colon = in.find_last_of(':');
	// if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
	bool fHaveColon = colon != in.npos;
	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
	bool fMultiColon = fHaveColon && (in.find_last_of(':', colon - 1) != in.npos);
	if (fHaveColon && (colon == 0 || fBracketed || !fMultiColon)) {
		int32_t n;
		if (ParseInt32(in.substr(colon + 1), &n) && n > 0 && n < 0x10000) {
			in = in.substr(0, colon);
			portOut = n;
		}
	}
	if (in.size()>0 && in[0] == '[' && in[in.size() - 1] == ']')
		hostOut = in.substr(1, in.size() - 2);
	else
		hostOut = in;
}

std::string EncodeBase64(const unsigned char* pch, size_t len)
{
	static const char *pbase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

	std::string str;
	str.reserve(((len + 2) / 3) * 4);
	ConvertBits<8, 6, true>([&](int v) { str += pbase64[v]; }, pch, pch + len);
	while (str.size() % 4) str += '=';
	return str;
}

std::string EncodeBase64(const std::string& str)
{
	return EncodeBase64((const unsigned char*)str.c_str(), str.size());
}

std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid)
{
	static const int decode64_table[256] =
	{
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1,
		-1, -1, -1, -1, -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
		15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28,
		29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
		49, 50, 51, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
	};

	const char* e = p;
	std::vector<uint8_t> val;
	val.reserve(strlen(p));
	while (*p != 0) {
		int x = decode64_table[(unsigned char)*p];
		if (x == -1) break;
		val.push_back(x);
		++p;
	}

	std::vector<unsigned char> ret;
	ret.reserve((val.size() * 3) / 4);
	bool valid = ConvertBits<6, 8, false>([&](unsigned char c) { ret.push_back(c); }, val.begin(), val.end());

	const char* q = p;
	while (valid && *p != 0) {
		if (*p != '=') {
			valid = false;
			break;
		}
		++p;
	}
	valid = valid && (p - e) % 4 == 0 && p - q < 4;
	if (pfInvalid) *pfInvalid = !valid;

	return ret;
}

std::string DecodeBase64(const std::string& str)
{
	std::vector<unsigned char> vchRet = DecodeBase64(str.c_str());
	return std::string((const char*)vchRet.data(), vchRet.size());
}

std::string EncodeBase32(const unsigned char* pch, size_t len)
{
	static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567";

	std::string str;
	str.reserve(((len + 4) / 5) * 8);
	ConvertBits<8, 5, true>([&](int v) { str += pbase32[v]; }, pch, pch + len);
	while (str.size() % 8) str += '=';
	return str;
}

std::string EncodeBase32(const std::string& str)
{
	return EncodeBase32((const unsigned char*)str.c_str(), str.size());
}

std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid)
{
	static const int decode32_table[256] =
	{
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, -1, -1, -1, -1,
		-1, -1, -1, -1, -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
		15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1,  0,  1,  2,
		3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
		23, 24, 25, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
	};

	const char* e = p;
	std::vector<uint8_t> val;
	val.reserve(strlen(p));
	while (*p != 0) {
		int x = decode32_table[(unsigned char)*p];
		if (x == -1) break;
		val.push_back(x);
		++p;
	}

	std::vector<unsigned char> ret;
	ret.reserve((val.size() * 5) / 8);
	bool valid = ConvertBits<5, 8, false>([&](unsigned char c) { ret.push_back(c); }, val.begin(), val.end());

	const char* q = p;
	while (valid && *p != 0) {
		if (*p != '=') {
			valid = false;
			break;
		}
		++p;
	}
	valid = valid && (p - e) % 8 == 0 && p - q < 8;
	if (pfInvalid) *pfInvalid = !valid;

	return ret;
}

std::string DecodeBase32(const std::string& str)
{
	std::vector<unsigned char> vchRet = DecodeBase32(str.c_str());
	return std::string((const char*)vchRet.data(), 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 = nullptr;
	errno = 0; // strtol will not set errno if valid
	long int n = strtol(str.c_str(), &endp, 10);
	if (out) *out = (int32_t)n;
	// Note that strtol returns a *long int*, so even if strtol doesn't report an 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.
	return endp && *endp == 0 && !errno &&
		n >= std::numeric_limits<int32_t>::min() &&
		n <= std::numeric_limits<int32_t>::max();
}

bool ParseInt64(const std::string& str, int64_t *out)
{
	if (!ParsePrechecks(str))
		return false;
	char *endp = nullptr;
	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 an 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 ParseUInt32(const std::string& str, uint32_t *out)
{
	if (!ParsePrechecks(str))
		return false;
	if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoul accepts these by default if they fit in the range
		return false;
	char *endp = nullptr;
	errno = 0; // strtoul will not set errno if valid
	unsigned long int n = strtoul(str.c_str(), &endp, 10);
	if (out) *out = (uint32_t)n;
	// Note that strtoul returns a *unsigned long int*, so even if it doesn't report an over/underflow
	// we still have to check that the returned value is within the range of an *uint32_t*. On 64-bit
	// platforms the size of these types may be different.
	return endp && *endp == 0 && !errno &&
		n <= std::numeric_limits<uint32_t>::max();
}

bool ParseUInt64(const std::string& str, uint64_t *out)
{
	if (!ParsePrechecks(str))
		return false;
	if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoull accepts these by default if they fit in the range
		return false;
	char *endp = nullptr;
	errno = 0; // strtoull will not set errno if valid
	unsigned long long int n = strtoull(str.c_str(), &endp, 10);
	if (out) *out = (uint64_t)n;
	// Note that strtoull returns a *unsigned long long int*, so even if it doesn't report an over/underflow
	// we still have to check that the returned value is within the range of an *uint64_t*.
	return endp && *endp == 0 && !errno &&
		n <= std::numeric_limits<uint64_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 ptr = 0;
	size_t indented = 0;
	while (ptr < in.size())
	{
		size_t lineend = in.find_first_of('\n', ptr);
		if (lineend == std::string::npos) {
			lineend = in.size();
		}
		const size_t linelen = lineend - ptr;
		const size_t rem_width = width - indented;
		if (linelen <= rem_width) {
			out << in.substr(ptr, linelen + 1);
			ptr = lineend + 1;
			indented = 0;
		}
		else {
			size_t finalspace = in.find_last_of(" \n", ptr + rem_width);
			if (finalspace == std::string::npos || finalspace < ptr) {
				// No place to break; just include the entire word and move on
				finalspace = in.find_first_of("\n ", ptr);
				if (finalspace == std::string::npos) {
					// End of the string, just add it and break
					out << in.substr(ptr);
					break;
				}
			}
			out << in.substr(ptr, finalspace - ptr) << "\n";
			if (in[finalspace] == '\n') {
				indented = 0;
			}
			else if (indent) {
				out << std::string(indent, ' ');
				indented = indent;
			}
			ptr = finalspace + 1;
		}
	}
	return out.str();
}

std::string i64tostr(int64_t n)
{
	return strprintf("%d", n);
}

std::string itostr(int n)
{
	return strprintf("%d", n);
}

int64_t atoi64(const char* psz)
{
#ifdef _MSC_VER
	return _atoi64(psz);
#else
	return strtoll(psz, nullptr, 10);
#endif
}

int64_t atoi64(const std::string& str)
{
#ifdef _MSC_VER
	return _atoi64(str.c_str());
#else
	return strtoll(str.c_str(), nullptr, 10);
#endif
}

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 = (int)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;
}