/* Test of getting random bytes.
Copyright (C) 2020-2022 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see . */
/* Written by Bruno Haible. */
#include
#include
#include "signature.h"
SIGNATURE_CHECK (getrandom, ssize_t, (void *, size_t, unsigned int));
#include
#include
#include "macros.h"
int
main (void)
{
char buf1[8];
char buf2[8];
char large_buf[100000];
ssize_t ret;
/* Check that different calls produce different results (with a high
probability). */
ret = getrandom (buf1, sizeof (buf1), 0);
if (ret < 0)
ASSERT (errno == ENOSYS);
else
{
ret = getrandom (buf2, sizeof (buf2), 0);
if (ret < 0)
ASSERT (errno == ENOSYS);
else
{
/* It is very unlikely that two calls to getrandom produce the
same results. */
ASSERT (memcmp (buf1, buf2, sizeof (buf1)) != 0);
}
}
/* Likewise with the "truly random" number generator. */
ret = getrandom (buf1, sizeof (buf1), GRND_RANDOM);
if (ret < 0)
ASSERT (errno == ENOSYS);
else
{
ret = getrandom (buf2, sizeof (buf2), GRND_RANDOM);
if (ret < 0)
ASSERT (errno == ENOSYS);
else
{
/* It is very unlikely that two calls to getrandom produce the
same results. */
ASSERT (memcmp (buf1, buf2, sizeof (buf1)) != 0);
}
}
/* Check that GRND_NONBLOCK works. */
ret = getrandom (large_buf, sizeof (large_buf), GRND_RANDOM | GRND_NONBLOCK);
ASSERT (ret <= (ssize_t) sizeof (large_buf));
/* It is very unlikely that so many truly random bytes were ready. */
if (ret < 0)
ASSERT (errno == ENOSYS || errno == EAGAIN
|| errno == EINVAL /* Solaris */);
else
ASSERT (ret > 0);
if (getrandom (buf1, 1, 0) < 1)
if (getrandom (buf1, 1, GRND_RANDOM) < 1)
{
fputs ("Skipping test: getrandom is ineffective\n", stderr);
return 77;
}
return 0;
}