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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>
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#include <qpdf/qpdf-config.h>
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#include <qpdf/QUtil.hh>
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#include <stdlib.h>
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InsecureRandomDataProvider::InsecureRandomDataProvider() :
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seeded_random(false)
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{
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}
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InsecureRandomDataProvider::~InsecureRandomDataProvider()
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{
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}
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void
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InsecureRandomDataProvider::provideRandomData(unsigned char* data, size_t len)
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{
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for (size_t i = 0; i < len; ++i)
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{
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data[i] = static_cast<unsigned char>((this->random() & 0xff0) >> 4);
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}
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}
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long
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InsecureRandomDataProvider::random()
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{
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if (! this->seeded_random)
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{
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// Seed the random number generator with something simple, but
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// just to be interesting, don't use the unmodified current
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// time. It would be better if this were a more secure seed.
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unsigned int seed = static_cast<unsigned int>(
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QUtil::get_current_time() ^ 0xcccc);
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#ifdef HAVE_RANDOM
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::srandom(seed);
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#else
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srand(seed);
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#endif
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this->seeded_random = true;
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}
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# ifdef HAVE_RANDOM
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return ::random();
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# else
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return rand();
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# endif
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}
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RandomDataProvider*
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InsecureRandomDataProvider::getInstance()
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{
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static InsecureRandomDataProvider instance;
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return &instance;
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}
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