checkbrute_crc/src/plugin_jamcrc.c

99 lines
2.5 KiB
C

/*
* Library: libjamcrc
* File: src/plugin_jamcrc.c
* Original Author: Lammert Bies
* Plugin Author: Syping
*
* This file is licensed under the MIT License as stated below
*
* Copyright (c) 1999-2016 Lammert Bies
* Copyright (c) 2020 Syping
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <stdbool.h>
#include "checksum.h"
static void init_crc32_tab(void);
static bool crc_tab32_init = false;
static uint32_t crc_tab32[256];
static void init_crc32_tab(void) {
uint32_t i;
uint32_t j;
uint32_t crc;
for (i = 0; i < 256; i++) {
crc = i;
for (j = 0; j < 8; j++) {
if (crc & 0x00000001L) {
crc = (crc >> 1) ^ CRC_POLY_32;
}
else {
crc = crc >> 1;
}
}
crc_tab32[i] = crc;
}
crc_tab32_init = true;
}
const char* checkbrute_format()
{
return "JAMCRC";
}
const char* checkbrute_version()
{
return "0.1";
}
uint32_t checkbrute_hash32(unsigned char* data, size_t size)
{
uint32_t crc;
uint32_t tmp;
uint32_t long_c;
const unsigned char *ptr;
size_t a;
if (!crc_tab32_init)
init_crc32_tab();
crc = CRC_START_32;
ptr = data;
if (ptr != NULL)
for (a = 0; a < size; a++) {
long_c = 0x000000FFL & (uint32_t)*ptr;
tmp = crc ^ long_c;
crc = (crc >> 8) ^ crc_tab32[tmp & 0xff];
ptr++;
}
crc ^= 0x00000000L;
return crc & 0xffffffffL;
}
int checkbrute_hashsz()
{
return 4;
}