mirror of
https://github.com/qpdf/qpdf.git
synced 2024-11-02 03:42:30 +00:00
130 lines
3.3 KiB
C++
130 lines
3.3 KiB
C++
#include <qpdf/SecureRandomDataProvider.hh>
|
|
|
|
#include <qpdf/QUtil.hh>
|
|
#include <qpdf/qpdf-config.h>
|
|
#ifdef _WIN32
|
|
# define WIN32_LEAN_AND_MEAN
|
|
# include <direct.h>
|
|
# include <io.h>
|
|
# include <windows.h>
|
|
# ifndef SKIP_OS_SECURE_RANDOM
|
|
# include <wincrypt.h>
|
|
# endif
|
|
#endif
|
|
|
|
#ifdef SKIP_OS_SECURE_RANDOM
|
|
|
|
void
|
|
SecureRandomDataProvider::provideRandomData(unsigned char* data, size_t len)
|
|
{
|
|
throw std::logic_error("SecureRandomDataProvider::provideRandomData called "
|
|
"when support was not compiled in");
|
|
}
|
|
|
|
RandomDataProvider*
|
|
SecureRandomDataProvider::getInstance()
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#else
|
|
|
|
# ifdef _WIN32
|
|
|
|
namespace
|
|
{
|
|
class WindowsCryptProvider
|
|
{
|
|
public:
|
|
WindowsCryptProvider()
|
|
{
|
|
if (!CryptAcquireContextW(
|
|
&crypt_prov,
|
|
NULL,
|
|
NULL,
|
|
PROV_RSA_FULL,
|
|
CRYPT_VERIFYCONTEXT)) {
|
|
throw std::runtime_error(
|
|
"unable to acquire crypt context: " + getErrorMessage());
|
|
}
|
|
}
|
|
~WindowsCryptProvider()
|
|
{
|
|
// Ignore error
|
|
CryptReleaseContext(crypt_prov, 0);
|
|
}
|
|
|
|
HCRYPTPROV crypt_prov;
|
|
|
|
private:
|
|
std::string
|
|
getErrorMessage()
|
|
{
|
|
DWORD errorMessageID = ::GetLastError();
|
|
LPSTR messageBuffer = nullptr;
|
|
size_t size = FormatMessageA(
|
|
FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
|
|
FORMAT_MESSAGE_IGNORE_INSERTS,
|
|
NULL,
|
|
errorMessageID,
|
|
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
|
|
reinterpret_cast<LPSTR>(&messageBuffer),
|
|
0,
|
|
NULL);
|
|
std::string message(messageBuffer, size);
|
|
LocalFree(messageBuffer);
|
|
return (
|
|
"error number " +
|
|
QUtil::int_to_string_base(errorMessageID, 16) + ": " + message);
|
|
}
|
|
};
|
|
} // namespace
|
|
# endif
|
|
|
|
void
|
|
SecureRandomDataProvider::provideRandomData(unsigned char* data, size_t len)
|
|
{
|
|
# if defined(_WIN32)
|
|
|
|
// Optimization: make the WindowsCryptProvider static as long as
|
|
// it can be done in a thread-safe fashion.
|
|
WindowsCryptProvider c;
|
|
if (!CryptGenRandom(
|
|
c.crypt_prov,
|
|
static_cast<DWORD>(len),
|
|
reinterpret_cast<BYTE*>(data))) {
|
|
throw std::runtime_error("unable to generate secure random data");
|
|
}
|
|
|
|
# elif defined(RANDOM_DEVICE)
|
|
|
|
// Optimization: wrap the file open and close in a class so that
|
|
// the file is closed in a destructor, then make this static to
|
|
// keep the file handle open. Only do this if it can be done in a
|
|
// thread-safe fashion.
|
|
FILE* f = QUtil::safe_fopen(RANDOM_DEVICE, "rb");
|
|
size_t fr = fread(data, 1, len, f);
|
|
fclose(f);
|
|
if (fr != len) {
|
|
throw std::runtime_error(
|
|
"unable to read " + QUtil::uint_to_string(len) + " bytes from " +
|
|
std::string(RANDOM_DEVICE));
|
|
}
|
|
|
|
# else
|
|
|
|
# error \
|
|
"Don't know how to generate secure random numbers on this platform. See random number generation in the top-level README.md"
|
|
|
|
# endif
|
|
}
|
|
|
|
RandomDataProvider*
|
|
SecureRandomDataProvider::getInstance()
|
|
{
|
|
static SecureRandomDataProvider instance;
|
|
return &instance;
|
|
}
|
|
|
|
#endif
|