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Diffstat (limited to 'wsutil/crc16.h')
-rw-r--r-- | wsutil/crc16.h | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/wsutil/crc16.h b/wsutil/crc16.h new file mode 100644 index 0000000..2c1be91 --- /dev/null +++ b/wsutil/crc16.h @@ -0,0 +1,113 @@ +/** @file + * Declaration of CRC-16 routines and table + * + * 2004 Richard van der Hoff <richardv@mxtelecom.com> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later +*/ + +#ifndef __CRC16_H__ +#define __CRC16_H__ + +#include <wireshark.h> + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Calculate the CCITT/ITU/CRC-16 16-bit CRC + + (parameters for this CRC are: + Polynomial: x^16 + x^12 + x^5 + 1 (0x1021); + Start value 0xFFFF; + XOR result with 0xFFFF; + First bit is LSB) +*/ + +/** Compute CRC16 CCITT checksum of a buffer of data. + @param buf The buffer containing the data. + @param len The number of bytes to include in the computation. + @return The CRC16 CCITT checksum. */ +WS_DLL_PUBLIC uint16_t crc16_ccitt(const uint8_t *buf, unsigned len); + +/** Compute CRC16 X.25 CCITT checksum of a buffer of data. + @param buf The buffer containing the data. + @param len The number of bytes to include in the computation. + @return The CRC16 X.25 CCITT checksum. */ +WS_DLL_PUBLIC uint16_t crc16_x25_ccitt_seed(const uint8_t *buf, unsigned len, uint16_t seed); + +/** Compute CRC16 CCITT checksum of a buffer of data. If computing the + * checksum over multiple buffers and you want to feed the partial CRC16 + * back in, remember to take the 1's complement of the partial CRC16 first. + @param buf The buffer containing the data. + @param len The number of bytes to include in the computation. + @param seed The seed to use. + @return The CRC16 CCITT checksum (using the given seed). */ +WS_DLL_PUBLIC uint16_t crc16_ccitt_seed(const uint8_t *buf, unsigned len, uint16_t seed); + +/** Compute the 16bit CRC_A value of a buffer as defined in ISO14443-3. + @param buf The buffer containing the data. + @param len The number of bytes to include in the computation. + @return the CRC16 checksum for the buffer */ +WS_DLL_PUBLIC uint16_t crc16_iso14443a(const uint8_t *buf, unsigned len); + +/** Compute the 16bit CRC value of a buffer as defined in USB Specification. + @param buf The buffer containing the data. + @param len The number of bytes to include in the computation. + @return the CRC16 checksum for the buffer */ +WS_DLL_PUBLIC uint16_t crc16_usb(const uint8_t *buf, unsigned len); + +/** Calculates a CRC16 checksum for the given buffer with the polynom + * 0x5935 using a precompiled CRC table + * @param buf a pointer to a buffer of the given length + * @param len the length of the given buffer + * @param seed The seed to use. + * @return the CRC16 checksum for the buffer + */ +WS_DLL_PUBLIC uint16_t crc16_0x5935(const uint8_t *buf, uint32_t len, uint16_t seed); + +/** Calculates a CRC16 checksum for the given buffer with the polynom + * 0x755B using a precompiled CRC table + * @param buf a pointer to a buffer of the given length + * @param len the length of the given buffer + * @param seed The seed to use. + * @return the CRC16 checksum for the buffer + */ +WS_DLL_PUBLIC uint16_t crc16_0x755B(const uint8_t *buf, uint32_t len, uint16_t seed); + +/** Computes CRC16 checksum for the given data with the polynom 0x9949 using + * precompiled CRC table + * @param buf a pointer to a buffer of the given length + * @param len the length of the given buffer + * @param seed The seed to use. + * @return the CRC16 checksum for the buffer + */ +WS_DLL_PUBLIC uint16_t crc16_0x9949_seed(const uint8_t *buf, unsigned len, uint16_t seed); + +/** Computes CRC16 checksum for the given data with the polynom 0x3D65 using + * precompiled CRC table + * @param buf a pointer to a buffer of the given length + * @param len the length of the given buffer + * @param seed The seed to use. + * @return the CRC16 checksum for the buffer + */ +WS_DLL_PUBLIC uint16_t crc16_0x3D65_seed(const uint8_t *buf, unsigned len, uint16_t seed); + +/** Computes CRC16 checksum for the given data with the polynom 0x080F using + * precompiled CRC table + * @param buf a pointer to a buffer of the given length + * @param len the length of the given buffer + * @param seed The seed to use. + * @return the CRC16 checksum for the buffer + */ +WS_DLL_PUBLIC uint16_t crc16_0x080F_seed(const uint8_t *buf, unsigned len, uint16_t seed); + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* crc16.h */ |