// Copyright (c) 2017-2020, 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 <boost/optional/optional.hpp>
#include <limits>
#include <string.h>
#include "memwipe.h"
#include "misc_log_ex.h"
#include "wipeable_string.h"
static constexpr const char hex[] = u8"0123456789abcdef";
namespace
{
int atolower(int c)
{
if (c >= 'A' && c <= 'Z')
c |= 32;
return c;
}
}
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());
if (size() > 0)
memcpy(buffer.data(), other.c_str(), size());
}
wipeable_string::wipeable_string(std::string &&other)
{
grow(other.size());
if (size() > 0)
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));
if (size() > 0)
memcpy(buffer.data(), s, size());
}
wipeable_string::wipeable_string(const char *s, size_t len)
{
grow(len);
memcpy(buffer.data(), s, len);
}
wipeable_string::~wipeable_string()
{
wipe();
}
void wipeable_string::wipe()
{
if (!buffer.empty())
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]};
if (old_sz > 0)
{
memcpy(tmp.get(), buffer.data(), old_sz * sizeof(char));
memwipe(buffer.data(), old_sz * sizeof(char));
}
buffer.reserve(reserved);
buffer.resize(sz);
if (old_sz > 0)
{
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::operator+=(char c)
{
push_back(c);
}
void wipeable_string::append(const char *ptr, size_t len)
{
const size_t orgsz = size();
CHECK_AND_ASSERT_THROW_MES(orgsz < std::numeric_limits<size_t>::max() - len, "Appended data too large");
grow(orgsz + len);
if (len > 0)
memcpy(data() + orgsz, ptr, len);
}
void wipeable_string::operator+=(const char *s)
{
append(s, strlen(s));
}
void wipeable_string::operator+=(const epee::wipeable_string &s)
{
append(s.data(), s.size());
}
void wipeable_string::operator+=(const std::string &s)
{
append(s.c_str(), s.size());
}
void wipeable_string::trim()
{
size_t prefix = 0;
while (prefix < size() && data()[prefix] == ' ')
++prefix;
if (prefix > 0)
memmove(buffer.data(), buffer.data() + prefix, size() - prefix);
size_t suffix = 0;
while (suffix < size()-prefix && data()[size() - 1 - prefix - suffix] == ' ')
++suffix;
resize(size() - prefix - suffix);
}
void wipeable_string::split(std::vector<wipeable_string> &fields) const
{
fields.clear();
size_t len = size();
const char *ptr = data();
bool space = true;
while (len--)
{
const char c = *ptr++;
const bool space_prev = space;
space = std::isspace(c);
if (!space)
{
if (space_prev)
fields.push_back({});
fields.back().push_back(c);
}
}
}
boost::optional<epee::wipeable_string> wipeable_string::parse_hexstr() const
{
if (size() % 2 != 0)
return boost::none;
boost::optional<epee::wipeable_string> res = epee::wipeable_string("");
const size_t len = size();
const char *d = data();
res->grow(0, len / 2);
for (size_t i = 0; i < len; i += 2)
{
char c = atolower(d[i]);
const char *ptr0 = strchr(hex, c);
if (!ptr0)
return boost::none;
c = atolower(d[i+1]);
const char *ptr1 = strchr(hex, c);
if (!ptr1)
return boost::none;
res->push_back(((ptr0-hex)<<4) | (ptr1-hex));
}
return res;
}
char wipeable_string::pop_back()
{
const size_t sz = size();
CHECK_AND_ASSERT_THROW_MES(sz > 0, "Popping from an empty string");
const char c = buffer.back();
resize(sz - 1);
return c;
}
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;
}
}
