104 lines
3.0 KiB
C++
104 lines
3.0 KiB
C++
/* This file is part of identiconpp.
|
|
* Copyright © 2018 tastytea <tastytea@tastytea.de>
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, version 3.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <exception>
|
|
#include <stdexcept>
|
|
#include <algorithm>
|
|
#include <cmath>
|
|
#include "identiconpp.hpp"
|
|
#include "debug.hpp"
|
|
|
|
void Identiconpp::check_entropy(const string &digest, algorithm type)
|
|
{
|
|
if (std::any_of(digest.begin(), digest.end(), not_hex))
|
|
{
|
|
throw std::invalid_argument
|
|
(
|
|
"Colors must consist of hexadecimal digits (" + digest + ")."
|
|
);
|
|
}
|
|
|
|
uint16_t entropy_provided;
|
|
uint16_t entropy_required;
|
|
switch (type)
|
|
{
|
|
case algorithm::ltr_symmetric:
|
|
{
|
|
// Every char is 4 bit
|
|
entropy_provided = digest.length() * 4;
|
|
// We need bits for each field in half of the columns, +1 column if
|
|
// they are uneven. Then we need enough bits to pick a color.
|
|
entropy_required = (_columns / 2 + _columns % 2) * _rows
|
|
+ std::floor(std::log2(_foreground.size())) + 1;
|
|
break;
|
|
}
|
|
case algorithm::ltr_asymmetric:
|
|
{
|
|
entropy_provided = digest.length() * 4;
|
|
entropy_required = _columns * _rows
|
|
+ std::floor(std::log2(_foreground.size())) + 1;
|
|
break;
|
|
}
|
|
case algorithm::sigil:
|
|
{
|
|
entropy_provided = digest.length() / 2 * 8;
|
|
entropy_required = (_columns / 2 + _columns % 2) * _rows + 8;
|
|
break;
|
|
}
|
|
}
|
|
ttdebug << "entropy_provided=" << std::to_string(entropy_provided)
|
|
<< ", entropy_required=" << std::to_string(entropy_required) << '\n';
|
|
|
|
if (entropy_provided < entropy_required)
|
|
{
|
|
throw std::invalid_argument(
|
|
"Passed digest \"" + digest + "\" is not capable of providing " +
|
|
std::to_string(entropy_required) + " bits of entropy.");
|
|
}
|
|
}
|
|
|
|
bool Identiconpp::not_hex(const char c)
|
|
{
|
|
if (c >= 0x61 && c <= 0x66)
|
|
{ // a-f
|
|
return false;
|
|
}
|
|
if (c >= 0x30 && c <= 0x39)
|
|
{ // 0-9
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void Identiconpp::check_color(const string &color)
|
|
{
|
|
if (color.length() != 8)
|
|
{
|
|
throw std::invalid_argument
|
|
(
|
|
"Colors must consist of exactly 8 digits(" + color + ")."
|
|
);
|
|
}
|
|
if (std::any_of(color.begin(), color.end(), not_hex))
|
|
{
|
|
throw std::invalid_argument
|
|
(
|
|
"Colors must consist of hexadecimal digits (" + color + ")."
|
|
);
|
|
}
|
|
}
|