wownero/contrib/epee/src/wipeable_string.cpp

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2018-01-07 23:55:52 +00:00
// Copyright (c) 2017-2018, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <string.h>
#include "memwipe.h"
#include "misc_log_ex.h"
#include "wipeable_string.h"
namespace epee
{
wipeable_string::wipeable_string(const wipeable_string &other):
buffer(other.buffer)
{
}
wipeable_string::wipeable_string(wipeable_string &&other)
{
if (&other == this)
return;
buffer = std::move(other.buffer);
}
wipeable_string::wipeable_string(const std::string &other)
{
grow(other.size());
memcpy(buffer.data(), other.c_str(), size());
}
wipeable_string::wipeable_string(std::string &&other)
{
grow(other.size());
memcpy(buffer.data(), other.c_str(), size());
if (!other.empty())
{
memwipe(&other[0], other.size()); // we're kinda left with this again aren't we
other = std::string();
}
}
wipeable_string::wipeable_string(const char *s)
{
grow(strlen(s));
memcpy(buffer.data(), s, size());
}
wipeable_string::~wipeable_string()
{
wipe();
}
void wipeable_string::wipe()
{
memwipe(buffer.data(), buffer.size() * sizeof(char));
}
void wipeable_string::grow(size_t sz, size_t reserved)
{
if (reserved < sz)
reserved = sz;
if (reserved <= buffer.capacity())
{
if (sz < buffer.size())
memwipe(buffer.data() + sz, buffer.size() - sz);
buffer.resize(sz);
return;
}
size_t old_sz = buffer.size();
std::unique_ptr<char[]> tmp{new char[old_sz]};
memcpy(tmp.get(), buffer.data(), old_sz * sizeof(char));
memwipe(buffer.data(), old_sz * sizeof(char));
buffer.reserve(reserved);
buffer.resize(sz);
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memcpy(buffer.data(), tmp.get(), old_sz * sizeof(char));
memwipe(tmp.get(), old_sz * sizeof(char));
}
void wipeable_string::push_back(char c)
{
grow(size() + 1);
buffer.back() = c;
}
void wipeable_string::pop_back()
{
resize(size() - 1);
}
void wipeable_string::resize(size_t sz)
{
grow(sz);
}
void wipeable_string::reserve(size_t sz)
{
grow(size(), sz);
}
void wipeable_string::clear()
{
resize(0);
}
wipeable_string &wipeable_string::operator=(wipeable_string &&other)
{
if (&other != this)
buffer = std::move(other.buffer);
return *this;
}
wipeable_string &wipeable_string::operator=(const wipeable_string &other)
{
if (&other != this)
buffer = other.buffer;
return *this;
}
}