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e99acd00cc
CHG: since sim commands are timing critical, I'm testing a smaller prand prng function from Intel
31 lines
886 B
C
31 lines
886 B
C
#include "random.h"
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static uint32_t g_nextrandom;
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/* Generates a (non-cryptographically secure) 32-bit random number.
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*
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* We don't have an implementation of the "rand" function. Instead we use a
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* method of seeding with the time it took to call "autoseed" from first run.
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*
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* https://github.com/Proxmark/proxmark3/pull/209/commits/f9c1dcd9f6e68a8c07cffed697a9c4c8caed6015
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*
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* Iceman, rand needs to be fast.
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* https://software.intel.com/en-us/articles/fast-random-number-generator-on-the-intel-pentiumr-4-processor/
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*/
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inline void fast_prand(){
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fast_prandEx(GetTickCount());
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}
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inline void fast_prandEx(uint32_t seed) {
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g_nextrandom = seed;
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}
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uint32_t prand() {
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// g_nextrandom *= 6364136223846793005;
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// g_nextrandom += 1;
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//return (uint32_t)(g_nextrandom >> 32) % 0xffffffff;
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g_nextrandom = (214013 * g_nextrandom + 2531011);
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return (g_nextrandom>>16) & 0xFFFF;
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}
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