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crc64.c
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/*
* This file is part of the Aaru Data Preservation Suite.
* Copyright (c) 2019-2026 Natalia Portillo.
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of the
* License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <aaruformat.h>
#include "log.h"
AARU_EXPORT crc64_ctx *AARU_CALL aaruf_crc64_init(void)
{
TRACE("Entering aaruf_crc64_init()");
crc64_ctx *ctx = malloc(sizeof(crc64_ctx));
if(!ctx) return NULL;
ctx->crc = CRC64_ECMA_SEED;
TRACE("Exiting aaruf_crc64_init()");
return ctx;
}
AARU_EXPORT int AARU_CALL aaruf_crc64_update(crc64_ctx *ctx, const uint8_t *data, uint32_t len)
{
TRACE("Entering aaruf_crc64_update(%p, %p, %u)", ctx, data, len);
if(!ctx || !data)
{
TRACE("Exiting aaruf_crc64_update() = -1");
return -1;
}
#if defined(__x86_64__) || defined(__amd64) || defined(_M_AMD64) || defined(_M_X64) || defined(__I386__) || \
defined(__i386__) || defined(__THW_INTEL) || defined(_M_IX86)
if(have_clmul())
{
ctx->crc = ~aaruf_crc64_clmul(~ctx->crc, data, len);
TRACE("Exiting aaruf_crc64_update() = 0");
return 0;
}
#endif
#if defined(__aarch64__) || defined(_M_ARM64) || defined(__arm__) || defined(_M_ARM)
if(have_neon())
{
ctx->crc = ~aaruf_crc64_vmull(~ctx->crc, data, len);
TRACE("Exiting aaruf_crc64_update() = 0");
return 0;
}
#endif
// Unroll according to Intel slicing by uint8_t
// http://www.intel.com/technology/comms/perfnet/download/CRC_generators.pdf
// http://sourceforge.net/projects/slicing-by-8/
aaruf_crc64_slicing(&ctx->crc, data, len);
TRACE("Exiting aaruf_crc64_update() = 0");
return 0;
}
AARU_EXPORT void AARU_CALL aaruf_crc64_slicing(uint64_t *previous_crc, const uint8_t *data, uint32_t len)
{
uint64_t c = *previous_crc;
if(len > 4)
{
const uint8_t *limit = NULL;
while((uintptr_t)data & 3)
{
c = crc64_table[0][*data++ ^ c & 0xFF] ^ c >> 8;
--len;
}
limit = data + (len & ~(uint32_t)3);
len &= (uint32_t)3;
while(data < limit)
{
const uint32_t tmp = c ^ *(const uint32_t *)data;
data += 4;
c = crc64_table[3][(tmp & 0xFF)] ^ crc64_table[2][(tmp >> 8 & 0xFF)] ^ c >> 32 ^
crc64_table[1][(tmp >> 16 & 0xFF)] ^ crc64_table[0][(tmp >> 24)];
}
}
while(len-- != 0) c = crc64_table[0][*data++ ^ c & 0xFF] ^ c >> 8;
*previous_crc = c;
}
AARU_EXPORT int AARU_CALL aaruf_crc64_final(crc64_ctx *ctx, uint64_t *crc)
{
if(!ctx) return -1;
*crc = ctx->crc ^ CRC64_ECMA_SEED;
return 0;
}
AARU_EXPORT void AARU_CALL aaruf_crc64_free(crc64_ctx *ctx)
{
if(ctx) free(ctx);
}
AARU_EXPORT uint64_t AARU_CALL aaruf_crc64_data(const uint8_t *data, const uint32_t len)
{
crc64_ctx *ctx = aaruf_crc64_init();
uint64_t crc = 0;
if(!ctx) return crc;
aaruf_crc64_update(ctx, data, len);
aaruf_crc64_final(ctx, &crc);
aaruf_crc64_free(ctx);
return crc;
}
aaruformat.h
aaruf_crc64_update
int aaruf_crc64_update(crc64_ctx *ctx, const uint8_t *data, uint32_t len)
Updates the CRC64 context with new data.
Definition crc64.c:55
aaruf_crc64_free
void aaruf_crc64_free(crc64_ctx *ctx)
Frees a CRC64 context.
Definition crc64.c:155
aaruf_crc64_slicing
void aaruf_crc64_slicing(uint64_t *previous_crc, const uint8_t *data, uint32_t len)
Updates a CRC64 value using the slicing-by-8 algorithm.
Definition crc64.c:102
aaruf_crc64_data
uint64_t aaruf_crc64_data(const uint8_t *data, const uint32_t len)
Definition crc64.c:160
aaruf_crc64_final
int aaruf_crc64_final(crc64_ctx *ctx, uint64_t *crc)
Computes the final CRC64 value from the context.
Definition crc64.c:141
aaruf_crc64_init
crc64_ctx * aaruf_crc64_init(void)
Initializes a CRC64 context.
Definition crc64.c:32
crc64_table
static const uint64_t crc64_table[4][256]
Precomputed slicing-by-4 ECMA-182 CRC64 lookup tables (4 * 256 * 8 = 8192 bytes).
Definition crc64.h:66
CRC64_ECMA_SEED
#define CRC64_ECMA_SEED
ECMA-182 initial seed (all bits set).
Definition crc64.h:280
AARU_CALL
#define AARU_CALL
Definition decls.h:46
AARU_EXPORT
#define AARU_EXPORT
Definition decls.h:55
log.h
TRACE
#define TRACE(fmt,...)
Definition log.h:25
crc64_ctx
Minimal ECMA-182 CRC64 incremental state container (running value only).
Definition crc64.h:56
crc64_ctx::crc
uint64_t crc
Running CRC value (initialize to CRC64_ECMA_SEED before first update).
Definition crc64.h:57