581ffa8a24
* grub-core/lib/crc64.c: Likewise. * grub-core/loader/i386/pc/plan9.c: Likewise. * grub-core/partmap/plan.c: Likewise.
153 lines
3.1 KiB
C
153 lines
3.1 KiB
C
/* adler32.c - adler32 check. */
|
|
/*
|
|
* GRUB -- GRand Unified Bootloader
|
|
* Copyright (C) 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+");
|
|
|
|
/* Based on adler32() from adler32.c of zlib-1.2.5 library. */
|
|
|
|
#define BASE 65521UL
|
|
#define NMAX 5552
|
|
|
|
#define DO1(buf,i) {adler += (buf)[i]; sum2 += adler;}
|
|
#define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
|
|
#define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
|
|
#define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
|
|
#define DO16(buf) DO8(buf,0); DO8(buf,8);
|
|
|
|
static grub_uint32_t
|
|
update_adler32 (grub_uint32_t adler, const grub_uint8_t *buf, grub_size_t len)
|
|
{
|
|
unsigned long sum2;
|
|
unsigned int n;
|
|
|
|
sum2 = (adler >> 16) & 0xffff;
|
|
adler &= 0xffff;
|
|
|
|
if (len == 1)
|
|
{
|
|
adler += buf[0];
|
|
if (adler >= BASE)
|
|
adler -= BASE;
|
|
sum2 += adler;
|
|
if (sum2 >= BASE)
|
|
sum2 -= BASE;
|
|
return adler | (sum2 << 16);
|
|
}
|
|
|
|
if (len < 16)
|
|
{
|
|
while (len--)
|
|
{
|
|
adler += *buf++;
|
|
sum2 += adler;
|
|
}
|
|
if (adler >= BASE)
|
|
adler -= BASE;
|
|
sum2 %= BASE;
|
|
return adler | (sum2 << 16);
|
|
}
|
|
|
|
while (len >= NMAX)
|
|
{
|
|
len -= NMAX;
|
|
n = NMAX / 16;
|
|
do
|
|
{
|
|
DO16 (buf);
|
|
buf += 16;
|
|
}
|
|
while (--n);
|
|
adler %= BASE;
|
|
sum2 %= BASE;
|
|
}
|
|
|
|
if (len)
|
|
{
|
|
while (len >= 16)
|
|
{
|
|
len -= 16;
|
|
DO16 (buf);
|
|
buf += 16;
|
|
}
|
|
while (len--)
|
|
{
|
|
adler += *buf++;
|
|
sum2 += adler;
|
|
}
|
|
adler %= BASE;
|
|
sum2 %= BASE;
|
|
}
|
|
|
|
return adler | (sum2 << 16);
|
|
}
|
|
|
|
typedef struct
|
|
{
|
|
grub_uint32_t adler;
|
|
}
|
|
adler32_context;
|
|
|
|
static void
|
|
adler32_init (void *context)
|
|
{
|
|
adler32_context *ctx = (adler32_context *) context;
|
|
ctx->adler = 1;
|
|
}
|
|
|
|
static void
|
|
adler32_write (void *context, const void *inbuf, grub_size_t inlen)
|
|
{
|
|
adler32_context *ctx = (adler32_context *) context;
|
|
if (!inbuf)
|
|
return;
|
|
ctx->adler = update_adler32 (ctx->adler, inbuf, inlen);
|
|
}
|
|
|
|
static grub_uint8_t *
|
|
adler32_read (void *context)
|
|
{
|
|
adler32_context *ctx = (adler32_context *) context;
|
|
return (grub_uint8_t *) &ctx->adler;
|
|
}
|
|
|
|
static void
|
|
adler32_final (void *context __attribute__ ((unused)))
|
|
{
|
|
}
|
|
|
|
gcry_md_spec_t _gcry_digest_spec_adler32 = {
|
|
"ADLER32",0 , 0, 0 , 4,
|
|
adler32_init, adler32_write, adler32_final, adler32_read,
|
|
sizeof (adler32_context),
|
|
.blocksize = 64
|
|
};
|
|
|
|
GRUB_MOD_INIT(adler32)
|
|
{
|
|
grub_md_register (&_gcry_digest_spec_adler32);
|
|
}
|
|
|
|
GRUB_MOD_FINI(adler32)
|
|
{
|
|
grub_md_unregister (&_gcry_digest_spec_adler32);
|
|
}
|