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