mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-12-04 13:23:26 +01:00
115 lines
2.5 KiB
C
115 lines
2.5 KiB
C
/* crc64.c - crc64 function */
|
|
/*
|
|
* GRUB -- GRand Unified Bootloader
|
|
* Copyright (C) 2008,2011 Free Software Foundation, Inc.
|
|
*
|
|
* GRUB 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.
|
|
*
|
|
* GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <grub/types.h>
|
|
#include <grub/dl.h>
|
|
#include <grub/crypto.h>
|
|
|
|
GRUB_MOD_LICENSE ("GPLv3+");
|
|
|
|
static grub_uint64_t crc64_table [256];
|
|
|
|
/* Helper for init_crc64_table. */
|
|
static grub_uint64_t
|
|
reflect (grub_uint64_t ref, int len)
|
|
{
|
|
grub_uint64_t result = 0;
|
|
int i;
|
|
|
|
for (i = 1; i <= len; i++)
|
|
{
|
|
if (ref & 1)
|
|
result |= 1ULL << (len - i);
|
|
ref >>= 1;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
static void
|
|
init_crc64_table (void)
|
|
{
|
|
grub_uint64_t polynomial = 0x42f0e1eba9ea3693ULL;
|
|
int i, j;
|
|
|
|
for(i = 0; i < 256; i++)
|
|
{
|
|
crc64_table[i] = reflect(i, 8) << 56;
|
|
for (j = 0; j < 8; j++)
|
|
{
|
|
crc64_table[i] = (crc64_table[i] << 1) ^
|
|
(crc64_table[i] & (1ULL << 63) ? polynomial : 0);
|
|
}
|
|
crc64_table[i] = reflect(crc64_table[i], 64);
|
|
}
|
|
}
|
|
|
|
static void
|
|
crc64_init (void *context)
|
|
{
|
|
if (! crc64_table[1])
|
|
init_crc64_table ();
|
|
*(grub_uint64_t *) context = 0;
|
|
}
|
|
|
|
static void
|
|
crc64_write (void *context, const void *buf, grub_size_t size)
|
|
{
|
|
unsigned i;
|
|
const grub_uint8_t *data = buf;
|
|
grub_uint64_t crc = ~grub_le_to_cpu64 (*(grub_uint64_t *) context);
|
|
|
|
for (i = 0; i < size; i++)
|
|
{
|
|
crc = (crc >> 8) ^ crc64_table[(crc & 0xFF) ^ *data];
|
|
data++;
|
|
}
|
|
|
|
*(grub_uint64_t *) context = grub_cpu_to_le64 (~crc);
|
|
}
|
|
|
|
static grub_uint8_t *
|
|
crc64_read (void *context)
|
|
{
|
|
return context;
|
|
}
|
|
|
|
static void
|
|
crc64_final (void *context __attribute__ ((unused)))
|
|
{
|
|
}
|
|
|
|
gcry_md_spec_t _gcry_digest_spec_crc64 =
|
|
{
|
|
"CRC64", 0, 0, 0, 8,
|
|
crc64_init, crc64_write, crc64_final, crc64_read,
|
|
sizeof (grub_uint64_t),
|
|
.blocksize = 64
|
|
};
|
|
|
|
GRUB_MOD_INIT(crc64)
|
|
{
|
|
grub_md_register (&_gcry_digest_spec_crc64);
|
|
}
|
|
|
|
GRUB_MOD_FINI(crc64)
|
|
{
|
|
grub_md_unregister (&_gcry_digest_spec_crc64);
|
|
}
|