#include "xtea.h"
#include<string.h>
#define TOUR 32

void encrypt_xtea(uint32_t v[2], uint32_t const key[4]) {
    unsigned int i;
    uint32_t v0=v[0], v1=v[1], sum=0, delta=0x9E3779B9;
    for (i=0; i < TOUR; i++) {
        v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + key[sum & 3]);
        sum += delta;
        v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + key[(sum>>11) & 3]);
    }
    v[0]=v0; v[1]=v1;
}
void decrypt_xtea(uint32_t v[2], uint32_t const key[4]) {
    unsigned int i;
    uint32_t v0=v[0], v1=v[1], delta=0x9E3779B9, sum=delta*TOUR;
    for (i=0; i < TOUR; i++) {
        v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + key[(sum>>11) & 3]);
        sum -= delta;
        v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + key[sum & 3]);
    }
    v[0]=v0; v[1]=v1;
}
uint64_t hash_block_xtea(char b[24])
{
	uint32_t v[2];
	uint32_t k[4];
	memcpy(v,b,2*sizeof(uint32_t));
	memcpy(k,b+2*sizeof(uint32_t),4*sizeof(uint32_t));
	encrypt_xtea(v,k);
	return ((uint64_t)v[0])<<32 | v[1];

}