/*

War Times CRC algorithm 0.1
by Luigi Auriemma
e-mail: aluigi@autistici.org
web:    aluigi.org

This is the simple CRC algorithm used for the network data of the game
War Times European Frontline http://www.lsgames.com
Usage example:

    u_char msg[] =
        "\x00\x00\x00\x00"
        "\x0e\x27\x00\x00"
        "Hello, I'm a chat message\0";
        *(u_int *)msg = wartimes_crc(msg, sizeof(msg) - 1);

remember that when you want to send the data you must first send 4 bytes
to specify the type of packet, 4 for the length of the data block and
then the data.

*/

unsigned int wartimes_crc(unsigned char *data, unsigned int len) {
    int             i;
    unsigned int   crc = 0x0000007f,
                    table[4] = {
                        0x0000162e,
                        0x000004d0,
                        0x00001994,
                        0x00002694
                    };

    data += 8;
    for(i = 8; i < len; i++) {
        crc += table[i & 3] + *data;
        data++;
    }
    return(crc);
}