matlab代做，FPGA代做，淘宝，专业代做MATLAB、FPGA博士/硕士/本科毕业设计、项目仿真、Coursework、Assignment
//XXTEA 简单，高效，安全。
//http://en.wikipedia.org/wiki/XXTEA
#define DELTA 0x9e3779b9
#define MX (((z>>5^y<<2) + (y>>3^z<<4)) ^ ((sum^y) + (key[(p&3)^e] ^ z)))
typedef unsigned long DWORD
//v是数据
//n是数据大小。n大于0，加密。小于0，解密
//key是密钥
void btea(DWORD *v, int n, DWORD key[4]) {
DWORD y, z, sum;
unsigned p, rounds, e;
if (n > 1) {
rounds = 6 + 52/n;
sum = 0;
z = v[n-1];
do {
sum += DELTA;
e = (sum >> 2) & 3;
for (p=0; p<n-1; p++) {
y = v[p+1];
z = v[p] += MX;
}
y = v[0];
z = v[n-1] += MX;
} while (--rounds);
} else if (n < -1) {
n = -n;
rounds = 6 + 52/n;
sum = rounds*DELTA;
y = v[0];
do {
e = (sum >> 2) & 3;
for (p=n-1; p>0; p--) {
z = v[p-1];
y = v[p] -= MX;
}
z = v[n-1];
y = v[0] -= MX;
} while ((sum -= DELTA) != 0);
}
}
