зеркало из https://github.com/github/putty.git
65 строки
1.3 KiB
C
65 строки
1.3 KiB
C
/*
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* uxgen.c: Unix implementation of get_heavy_noise() from cmdgen.c.
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*/
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#include <stdio.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include "putty.h"
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char *get_random_data(int len, const char *device)
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{
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char *buf = snewn(len, char);
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int fd;
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int ngot, ret;
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if (!device) {
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static const char *const default_devices[] = {
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"/dev/urandom", "/dev/random"
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};
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size_t i;
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for (i = 0; i < lenof(default_devices); i++) {
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if (access(default_devices[i], R_OK) == 0) {
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device = default_devices[i];
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break;
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}
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}
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if (!device) {
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sfree(buf);
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fprintf(stderr, "puttygen: cannot find a readable "
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"random number source; use --random-device\n");
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return NULL;
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}
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}
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fd = open(device, O_RDONLY);
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if (fd < 0) {
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sfree(buf);
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fprintf(stderr, "puttygen: %s: open: %s\n",
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device, strerror(errno));
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return NULL;
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}
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ngot = 0;
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while (ngot < len) {
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ret = read(fd, buf+ngot, len-ngot);
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if (ret < 0) {
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close(fd);
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sfree(buf);
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fprintf(stderr, "puttygen: %s: read: %s\n",
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device, strerror(errno));
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return NULL;
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}
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ngot += ret;
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}
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close(fd);
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return buf;
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}
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