49 lines
968 B
C
49 lines
968 B
C
#include <time.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include "xrandom.h"
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static int read_random(void *buf, int len)
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{
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int fd, rc, cnt;
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fd = open("/dev/urandom", O_RDONLY);
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if(fd == -1)
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return 0;
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cnt = 0;
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while(cnt < len) {
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rc = read(fd, ((char*)buf) + cnt, len - cnt);
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if(rc < 1) {
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/* -1 is error, but, well, EOF on /dev/urandom is even worse */
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close(fd);
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return 0;
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}
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cnt += rc;
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}
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close(fd);
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return 1;
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}
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void randomize()
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{
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unsigned int seed;
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int ok;
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ok = read_random(&seed, sizeof(seed));
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if(!ok) {
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seed = time(0) ^ (getpid() << 8);
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/* definitely worse, but better than nothing */
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}
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srand(seed);
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}
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void fill_random(void *buf, int len)
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{
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int i;
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for(i = 0; i < len; i++)
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((unsigned char*)buf)[i] = (rand() >> 7) & 0xff;
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}
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