git.zerfleddert.de Git - proxmark3-svn/blob - common/random.c

   1 #include "random.h"
   2
   3 static uint64_t next_random = 1;
   4
   5 /* Generates a (non-cryptographically secure) 32-bit random number.
   6  *
   7  * We don't have an implementation of the "rand" function. Instead we use a
   8  * method of seeding with the time it took to call "autoseed" from first run.
   9  *
  10  * https://github.com/Proxmark/proxmark3/pull/209/commits/f9c1dcd9f6e68a8c07cffed697a9c4c8caed6015
  11  */
  12 uint32_t prand() {
  13         if (next_random == 1)
  14                 next_random = GetTickCount();
  15
  16         next_random = next_random * 6364136223846793005 + 1;
  17         return (uint32_t)(next_random >> 32) % 0xffffffff;
  18 }
  19