vaseboot/VasEBoot-core/lib/random.c

121 lines
3.0 KiB
C

/*
* VAS_EBOOT -- GRand Unified Bootloader
* Copyright (C) 2016 Free Software Foundation, Inc.
*
* VAS_EBOOT 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.
*
* VAS_EBOOT 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 VAS_EBOOT. If not, see <http://www.gnu.org/licenses/>.
*/
#include <VasEBoot/random.h>
#include <VasEBoot/dl.h>
#include <VasEBoot/lib/hexdump.h>
#include <VasEBoot/command.h>
#include <VasEBoot/mm.h>
VAS_EBOOT_MOD_LICENSE ("GPLv3+");
VasEBoot_err_t
VasEBoot_crypto_get_random (void *buffer, VasEBoot_size_t sz)
{
/* This is an arbitrer between different methods.
TODO: Add more methods in the future. */
/* TODO: Add some PRNG smartness to reduce damage from bad entropy. */
if (VasEBoot_crypto_arch_get_random (buffer, sz))
return VAS_EBOOT_ERR_NONE;
return VasEBoot_error (VAS_EBOOT_ERR_IO, "no random sources found");
}
static int
get_num_digits (int val)
{
int ret = 0;
while (val != 0)
{
ret++;
val /= 10;
}
if (ret == 0)
return 1;
return ret;
}
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
static VasEBoot_err_t
VasEBoot_cmd_hexdump_random (VasEBoot_command_t cmd __attribute__ ((unused)), int argc, char **args)
{
VasEBoot_size_t length = 64;
VasEBoot_err_t err;
void *buffer;
VasEBoot_uint8_t *ptr;
int stats[256];
int i, digits = 2;
char template[10];
if (argc >= 1)
length = VasEBoot_strtoull (args[0], 0, 0);
if (length == 0)
return VasEBoot_error (VAS_EBOOT_ERR_BAD_ARGUMENT, "length pust be positive");
buffer = VasEBoot_malloc (length);
if (!buffer)
return VasEBoot_errno;
err = VasEBoot_crypto_get_random (buffer, length);
if (err)
{
VasEBoot_free (buffer);
return err;
}
hexdump (0, buffer, length);
VasEBoot_memset(stats, 0, sizeof(stats));
for (ptr = buffer; ptr < (VasEBoot_uint8_t *) buffer + length; ptr++)
stats[*ptr]++;
VasEBoot_printf ("Statistics:\n");
for (i = 0; i < 256; i++)
{
int z = get_num_digits (stats[i]);
if (z > digits)
digits = z;
}
VasEBoot_snprintf (template, sizeof (template), "%%0%dd ", digits);
for (i = 0; i < 256; i++)
{
VasEBoot_printf ("%s", template);//, stats[i]);
if ((i & 0xf) == 0xf)
VasEBoot_printf ("\n");
}
VasEBoot_free (buffer);
return 0;
}
static VasEBoot_command_t cmd;
VAS_EBOOT_MOD_INIT (random)
{
cmd = VasEBoot_register_command ("hexdump_random", VasEBoot_cmd_hexdump_random,
N_("[LENGTH]"),
N_("Hexdump random data."));
}
VAS_EBOOT_MOD_FINI (random)
{
VasEBoot_unregister_command (cmd);
}