libaaruformat 1.0 Aaru Data Preservation Suite - Format Library

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crc64.c
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1/*
2 * This file is part of the Aaru Data Preservation Suite.
3 * Copyright (c) 2019-2025 Natalia Portillo.
4 *
5 * This library is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License as
7 * published by the Free Software Foundation; either version 2.1 of the
8 * License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 */
18
19#include <stdlib.h>
20
21#include <aaruformat.h>
22
23#include "log.h"
24
32 AARU_EXPORT crc64_ctx *AARU_CALL aaruf_crc64_init(void)
33{
34 TRACE("Entering aaruf_crc64_init()");
35 crc64_ctx *ctx = malloc(sizeof(crc64_ctx));
36
37 if(!ctx) return NULL;
38
39 ctx->crc = CRC64_ECMA_SEED;
40
41 TRACE("Exiting aaruf_crc64_init()");
42 return ctx;
43}
44
55 AARU_EXPORT int AARU_CALL aaruf_crc64_update(crc64_ctx *ctx, const uint8_t *data, uint32_t len)
56{
57 TRACE("Entering aaruf_crc64_update(%p, %p, %u)", ctx, data, len);
58 if(!ctx || !data)
59 {
60 TRACE("Exiting aaruf_crc64_update() = -1");
61 return -1;
62 }
63
64#if defined(__x86_64__) || defined(__amd64) || defined(_M_AMD64) || defined(_M_X64) || defined(__I386__) || \
65 defined(__i386__) || defined(__THW_INTEL) || defined(_M_IX86)
66 if(have_clmul())
67 {
68 ctx->crc = ~aaruf_crc64_clmul(~ctx->crc, data, len);
69
70 TRACE("Exiting aaruf_crc64_update() = 0");
71 return 0;
72 }
73#endif
74
75#if defined(__aarch64__) || defined(_M_ARM64) || defined(__arm__) || defined(_M_ARM)
76 if(have_neon())
77 {
78 ctx->crc = ~aaruf_crc64_vmull(~ctx->crc, data, len);
79
80 TRACE("Exiting aaruf_crc64_update() = 0");
81 return 0;
82 }
83#endif
84
85 // Unroll according to Intel slicing by uint8_t
86 // http://www.intel.com/technology/comms/perfnet/download/CRC_generators.pdf
87 // http://sourceforge.net/projects/slicing-by-8/
88
89 aaruf_crc64_slicing(&ctx->crc, data, len);
90
91 TRACE("Exiting aaruf_crc64_update() = 0");
92 return 0;
93}
94
102 AARU_EXPORT void AARU_CALL aaruf_crc64_slicing(uint64_t *previous_crc, const uint8_t *data, uint32_t len)
103{
104 uint64_t c = *previous_crc;
105
106 if(len > 4)
107 {
108 const uint8_t *limit = NULL;
109
110 while((uintptr_t)data & 3)
111 {
112 c = crc64_table[0][*data++ ^ c & 0xFF] ^ c >> 8;
113 --len;
114 }
115
116 limit = data + (len & ~(uint32_t)3);
117 len &= (uint32_t)3;
118
119 while(data < limit)
120 {
121 const uint32_t tmp = c ^ *(const uint32_t *)data;
122 data += 4;
123
124 c = crc64_table[3][(tmp & 0xFF)] ^ crc64_table[2][(tmp >> 8 & 0xFF)] ^ c >> 32 ^
125 crc64_table[1][(tmp >> 16 & 0xFF)] ^ crc64_table[0][(tmp >> 24)];
126 }
127 }
128
129 while(len-- != 0) c = crc64_table[0][*data++ ^ c & 0xFF] ^ c >> 8;
130
131 *previous_crc = c;
132}
133
141 AARU_EXPORT int AARU_CALL aaruf_crc64_final(crc64_ctx *ctx, uint64_t *crc)
142{
143 if(!ctx) return -1;
144
145 *crc = ctx->crc ^ CRC64_ECMA_SEED;
146
147 return 0;
148}
149
155 AARU_EXPORT void AARU_CALL aaruf_crc64_free(crc64_ctx *ctx)
156{
157 if(ctx) free(ctx);
158}
159
160 AARU_EXPORT uint64_t AARU_CALL aaruf_crc64_data(const uint8_t *data, const uint32_t len)
161{
162 crc64_ctx *ctx = aaruf_crc64_init();
163 uint64_t crc = 0;
164
165 if(!ctx) return crc;
166
167 aaruf_crc64_update(ctx, data, len);
168 aaruf_crc64_final(ctx, &crc);
169 aaruf_crc64_free(ctx);
170
171 return crc;
172}
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:45
AARU_EXPORT
#define AARU_EXPORT
Definition decls.h:54
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