ext-cryptopp/files.cpp
2021-02-28 08:37:31 -05:00

301 lines
7.4 KiB
C++

// files.cpp - originally written and placed in the public domain by Wei Dai
#include "pch.h"
#ifndef CRYPTOPP_IMPORTS
#include "files.h"
#include <iostream>
#include <fstream>
#include <limits>
ANONYMOUS_NAMESPACE_BEGIN
/// \brief Disable badbit, failbit and eof exceptions
/// \sa https://github.com/weidai11/cryptopp/pull/968 and
/// https://www.cplusplus.com/reference/ios/ios/exceptions
class IosExceptionMask
{
public:
IosExceptionMask(std::istream& stream) : m_stream(stream) {
m_mask = m_stream.exceptions();
m_stream.exceptions(static_cast<std::ios::iostate>(0));
}
IosExceptionMask(std::istream& stream, std::ios::iostate newMask) : m_stream(stream) {
m_mask = m_stream.exceptions();
m_stream.exceptions(newMask);
}
~IosExceptionMask() {
m_stream.exceptions(m_mask);
}
private:
std::istream& m_stream;
std::ios::iostate m_mask;
};
ANONYMOUS_NAMESPACE_END
NAMESPACE_BEGIN(CryptoPP)
#if defined(CRYPTOPP_DEBUG) && !defined(CRYPTOPP_DOXYGEN_PROCESSING)
void Files_TestInstantiations()
{
FileStore f0;
FileSource f1;
FileSink f2;
}
#endif
void FileStore::StoreInitialize(const NameValuePairs &parameters)
{
m_waiting = false;
m_stream = NULLPTR;
m_file.release();
const char *fileName = NULLPTR;
#if defined(CRYPTOPP_UNIX_AVAILABLE) || _MSC_VER >= 1400
const wchar_t *fileNameWide = NULLPTR;
if (!parameters.GetValue(Name::InputFileNameWide(), fileNameWide))
#endif
if (!parameters.GetValue(Name::InputFileName(), fileName))
{
parameters.GetValue(Name::InputStreamPointer(), m_stream);
return;
}
std::ios::openmode binary = parameters.GetValueWithDefault(Name::InputBinaryMode(), true) ? std::ios::binary : std::ios::openmode(0);
m_file.reset(new std::ifstream);
#ifdef CRYPTOPP_UNIX_AVAILABLE
std::string narrowed;
if (fileNameWide)
fileName = (narrowed = StringNarrow(fileNameWide)).c_str();
#endif
#if _MSC_VER >= 1400
if (fileNameWide)
{
m_file->open(fileNameWide, std::ios::in | binary);
if (!*m_file)
throw OpenErr(StringNarrow(fileNameWide, false));
}
#endif
if (fileName)
{
m_file->open(fileName, std::ios::in | binary);
if (!*m_file)
throw OpenErr(fileName);
}
m_stream = m_file.get();
}
lword FileStore::MaxRetrievable() const
{
if (!m_stream)
return 0;
// Disable badbit, failbit and eof exceptions
IosExceptionMask guard(*m_stream);
// Clear error bits due to seekg(). Also see
// https://github.com/weidai11/cryptopp/pull/968
std::streampos current = m_stream->tellg();
std::streampos end = m_stream->seekg(0, std::ios::end).tellg();
m_stream->clear();
m_stream->seekg(current);
m_stream->clear();
// Return max for a non-seekable stream
// https://www.cplusplus.com/reference/istream/istream/tellg
if (end == static_cast<std::streampos>(-1))
return LWORD_MAX;
return end-current;
}
size_t FileStore::TransferTo2(BufferedTransformation &target, lword &transferBytes, const std::string &channel, bool blocking)
{
if (!m_stream)
{
transferBytes = 0;
return 0;
}
lword size=transferBytes;
transferBytes = 0;
if (m_waiting)
goto output;
size_t spaceSize, blockedBytes;
while (size && m_stream->good())
{
spaceSize = 1024;
m_space = HelpCreatePutSpace(target, channel, 1, UnsignedMin(size_t(SIZE_MAX), size), spaceSize);
m_stream->read((char *)m_space, (std::streamsize)STDMIN(size, (lword)spaceSize));
m_len = (size_t)m_stream->gcount();
output:
blockedBytes = target.ChannelPutModifiable2(channel, m_space, m_len, 0, blocking);
m_waiting = blockedBytes > 0;
if (m_waiting)
return blockedBytes;
size -= m_len;
transferBytes += m_len;
}
if (!m_stream->good() && !m_stream->eof())
throw ReadErr();
return 0;
}
size_t FileStore::CopyRangeTo2(BufferedTransformation &target, lword &begin, lword end, const std::string &channel, bool blocking) const
{
if (!m_stream)
return 0;
if (begin == 0 && end == 1)
{
int result = m_stream->peek();
if (result == std::char_traits<char>::eof())
return 0;
else
{
size_t blockedBytes = target.ChannelPut(channel, byte(result), blocking);
begin += 1-blockedBytes;
return blockedBytes;
}
}
// TODO: figure out what happens on cin
std::streampos current = m_stream->tellg();
std::streampos endPosition = m_stream->seekg(0, std::ios::end).tellg();
std::streampos newPosition = current + static_cast<std::streamoff>(begin);
if (newPosition >= endPosition)
{
m_stream->seekg(current);
return 0; // don't try to seek beyond the end of file
}
m_stream->seekg(newPosition);
try
{
CRYPTOPP_ASSERT(!m_waiting);
lword copyMax = end-begin;
size_t blockedBytes = const_cast<FileStore *>(this)->TransferTo2(target, copyMax, channel, blocking);
begin += copyMax;
if (blockedBytes)
{
const_cast<FileStore *>(this)->m_waiting = false;
return blockedBytes;
}
}
catch(...)
{
m_stream->clear();
m_stream->seekg(current);
throw;
}
m_stream->clear();
m_stream->seekg(current);
return 0;
}
lword FileStore::Skip(lword skipMax)
{
if (!m_stream)
return 0;
lword oldPos = m_stream->tellg();
std::istream::off_type offset;
if (!SafeConvert(skipMax, offset))
throw InvalidArgument("FileStore: maximum seek offset exceeded");
m_stream->seekg(offset, std::ios::cur);
return (lword)m_stream->tellg() - oldPos;
}
void FileSink::IsolatedInitialize(const NameValuePairs &parameters)
{
m_stream = NULLPTR;
m_file.release();
const char *fileName = NULLPTR;
#if defined(CRYPTOPP_UNIX_AVAILABLE) || _MSC_VER >= 1400
const wchar_t *fileNameWide = NULLPTR;
if (!parameters.GetValue(Name::OutputFileNameWide(), fileNameWide))
#endif
if (!parameters.GetValue(Name::OutputFileName(), fileName))
{
parameters.GetValue(Name::OutputStreamPointer(), m_stream);
return;
}
std::ios::openmode binary = parameters.GetValueWithDefault(Name::OutputBinaryMode(), true) ? std::ios::binary : std::ios::openmode(0);
m_file.reset(new std::ofstream);
#ifdef CRYPTOPP_UNIX_AVAILABLE
std::string narrowed;
if (fileNameWide)
fileName = (narrowed = StringNarrow(fileNameWide)).c_str();
#elif (CRYPTOPP_MSC_VERSION >= 1400)
if (fileNameWide)
{
m_file->open(fileNameWide, std::ios::out | std::ios::trunc | binary);
if (!*m_file)
throw OpenErr(StringNarrow(fileNameWide, false));
}
#endif
if (fileName)
{
m_file->open(fileName, std::ios::out | std::ios::trunc | binary);
if (!*m_file)
throw OpenErr(fileName);
}
m_stream = m_file.get();
}
bool FileSink::IsolatedFlush(bool hardFlush, bool blocking)
{
CRYPTOPP_UNUSED(hardFlush), CRYPTOPP_UNUSED(blocking);
if (!m_stream)
throw Err("FileSink: output stream not opened");
m_stream->flush();
if (!m_stream->good())
throw WriteErr();
return false;
}
size_t FileSink::Put2(const byte *inString, size_t length, int messageEnd, bool blocking)
{
CRYPTOPP_UNUSED(blocking);
if (!m_stream)
throw Err("FileSink: output stream not opened");
while (length > 0)
{
std::streamsize size;
if (!SafeConvert(length, size))
size = ((std::numeric_limits<std::streamsize>::max)());
m_stream->write((const char *)inString, size);
inString += size;
length -= (size_t)size;
}
if (messageEnd)
m_stream->flush();
if (!m_stream->good())
throw WriteErr();
return 0;
}
NAMESPACE_END
#endif