crc32.h File Reference

#include <stdint.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER)
u32	crc32_le (u32 seed, const void *data, size_t len)
	Calculate 32-bit little-endian CRC checksum.

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Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

u32 crc32_le	(	u32	seed,
		const void *	data,
		size_t	len
	)

Calculate 32-bit little-endian CRC checksum.

Parameters:

	seed	Initial value
	data	Data to checksum
	len	Length of data

Usually seed is initially zero or all one bits, depending on the protocol. To continue a CRC checksum over multiple calls, pass the return value from one call as the seed parameter to the next.

Definition at line 38 of file crc32.c.

References CRCPOLY, src, u32, and u8.

Referenced by tkip_decrypt(), tkip_encrypt(), wep_decrypt(), and wep_encrypt().

{
        u32 crc = seed;
        const u8 *src = data;
        u32 mult;
        int i;

        while ( len-- ) {
                crc ^= *src++;
                for ( i = 0; i < 8; i++ ) {
                        mult = ( crc & 1 ) ? CRCPOLY : 0;
                        crc = ( crc >> 1 ) ^ mult;
                }
        }

        return crc;
}