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#include "libbb.h"
#include <ntsecapi.h>
#include "../shell/random.h"
/*
* Obtain a few bytes of random-ish data to initialise the generator.
* This is unlikely to be very robust: don't rely on it for
* anything that needs to be secure.
*/
static void get_entropy(uint32_t state[2])
{
#if defined(__MINGW64_VERSION_MAJOR) && \
(__MINGW64_VERSION_MAJOR >= 7 || defined(__MINGW64__))
if (!RtlGenRandom(state, sizeof(state[0])*2))
#endif
GetSystemTimeAsFileTime((FILETIME *)state);
#if 0
{
unsigned char *p = (unsigned char *)state;
int j;
for (j=0; j<8; ++j) {
fprintf(stderr, "%02x", *p++);
if ((j&3) == 3) {
fprintf(stderr, " ");
}
}
fprintf(stderr, "\n");
}
#endif
}
ssize_t get_random_bytes(void *buf, ssize_t count)
{
static random_t rnd;
ssize_t save_count = count;
uint32_t value;
unsigned char *ptr = (unsigned char *)&value;
if (buf == NULL || count < 0) {
errno = EINVAL;
return -1;
}
if (UNINITED_RANDOM_T(&rnd)) {
uint32_t state[2] = {0, 0};
get_entropy(state);
INIT_RANDOM_T(&rnd, state[0] ? state[0] : 1, state[1]);
}
for (;count > 0; buf+=4, count-=4) {
value = full_random(&rnd);
memcpy(buf, ptr, count >= 4 ? 4 : count);
}
return save_count;
}
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