| /* |
| * Copyright (c) 2018 Workaround GmbH. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <sys/crc.h> |
| |
| uint32_t crc32_ieee(const uint8_t *data, size_t len) |
| { |
| return crc32_ieee_update(0x0, data, len); |
| } |
| |
| uint32_t crc32_ieee_update(uint32_t crc, const uint8_t *data, size_t len) |
| { |
| /* crc table generated from polynomial 0xedb88320 */ |
| static const uint32_t table[16] = { |
| 0x00000000U, 0x1db71064U, 0x3b6e20c8U, 0x26d930acU, |
| 0x76dc4190U, 0x6b6b51f4U, 0x4db26158U, 0x5005713cU, |
| 0xedb88320U, 0xf00f9344U, 0xd6d6a3e8U, 0xcb61b38cU, |
| 0x9b64c2b0U, 0x86d3d2d4U, 0xa00ae278U, 0xbdbdf21cU, |
| }; |
| |
| crc = ~crc; |
| |
| for (size_t i = 0; i < len; i++) { |
| uint8_t byte = data[i]; |
| |
| crc = (crc >> 4) ^ table[(crc ^ byte) & 0x0fU]; |
| crc = (crc >> 4) ^ table[(crc ^ ((uint32_t)byte >> 4)) & 0x0fU]; |
| } |
| |
| return (~crc); |
| } |