mirror of
https://github.com/qpdf/qpdf.git
synced 2024-11-16 17:45:09 +00:00
cb769c62e5
This comment expands all tabs using an 8-character tab-width. You should ignore this commit when using git blame or use git blame -w. In the early days, I used to use tabs where possible for indentation, since emacs did this automatically. In recent years, I have switched to only using spaces, which means qpdf source code has been a mixture of spaces and tabs. I have avoided cleaning this up because of not wanting gratuitous whitespaces change to cloud the output of git blame, but I changed my mind after discussing with users who view qpdf source code in editors/IDEs that have other tab widths by default and in light of the fact that I am planning to start applying automatic code formatting soon.
56 lines
1.2 KiB
C++
56 lines
1.2 KiB
C++
#include <qpdf/InsecureRandomDataProvider.hh>
|
|
|
|
#include <qpdf/qpdf-config.h>
|
|
#include <qpdf/QUtil.hh>
|
|
#include <stdlib.h>
|
|
|
|
InsecureRandomDataProvider::InsecureRandomDataProvider() :
|
|
seeded_random(false)
|
|
{
|
|
}
|
|
|
|
InsecureRandomDataProvider::~InsecureRandomDataProvider()
|
|
{
|
|
}
|
|
|
|
void
|
|
InsecureRandomDataProvider::provideRandomData(unsigned char* data, size_t len)
|
|
{
|
|
for (size_t i = 0; i < len; ++i)
|
|
{
|
|
data[i] = static_cast<unsigned char>((this->random() & 0xff0) >> 4);
|
|
}
|
|
}
|
|
|
|
long
|
|
InsecureRandomDataProvider::random()
|
|
{
|
|
if (! this->seeded_random)
|
|
{
|
|
// Seed the random number generator with something simple, but
|
|
// just to be interesting, don't use the unmodified current
|
|
// time. It would be better if this were a more secure seed.
|
|
unsigned int seed = static_cast<unsigned int>(
|
|
QUtil::get_current_time() ^ 0xcccc);
|
|
#ifdef HAVE_RANDOM
|
|
::srandom(seed);
|
|
#else
|
|
srand(seed);
|
|
#endif
|
|
this->seeded_random = true;
|
|
}
|
|
|
|
# ifdef HAVE_RANDOM
|
|
return ::random();
|
|
# else
|
|
return rand();
|
|
# endif
|
|
}
|
|
|
|
RandomDataProvider*
|
|
InsecureRandomDataProvider::getInstance()
|
|
{
|
|
static InsecureRandomDataProvider instance;
|
|
return &instance;
|
|
}
|