#define ITER 8
typedef unsigned long uint32_t;

/* encrypt
 *   Encrypt 64 bits with a 128 bit key using TEA
 *   From http://en.wikipedia.org/wiki/Tiny_Encryption_Algorithm
 * Arguments:
 *   v - array of two 32 bit uints to be encoded in place
 *   k - array of four 32 bit uints to act as key
 * Returns:
 *   w - encrypted result
 * Side effects:
 *   None
 */
void encrypt (uint32_t *v, const uint32_t k[4], uint32_t *w) {
	uint32_t v0=v[0], v1=v[1], sum=0, i;           /* set up */
	uint32_t delta=0x9e3779b9;                     /* a key schedule constant */
	uint32_t k0=k[0], k1=k[1], k2=k[2], k3=k[3];   /* cache key */

encrypt_loop: for (i=0; i < ITER; i++) {           /* basic cycle start */
        sum += delta;
        v0 += ((v1<<4) + k0) ^ (v1 + sum) ^ ((v1>>5) + k1);
        v1 += ((v0<<4) + k2) ^ (v0 + sum) ^ ((v0>>5) + k3);  
    }                                              /* end cycle */
    w[0]=v0; w[1]=v1;

}