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#include <qpdf/InsecureRandomDataProvider.hh>
#include <qpdf/QUtil.hh>
#include <qpdf/qpdf-config.h>
#include <cstdlib>
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.
auto 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;
}
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