BTEA算法C语言实现

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#include <iostream>
#include <stdio.h>

using namespace std;

#include <stdint.h>
#define DELTA 0x9e3779b9
#define MX (((z>>5^y<<2) + (y>>3^z<<4)) ^ ((sum^y) + (key[(p&3)^e] ^ z)))

  void btea(uint32_t *v, int n, uint32_t const key[4]) {
    uint32_t y, z, sum;
    unsigned p, rounds, e;
    if (n > 1) {          /* Coding Part */
      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) {  /* Decoding Part */
      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);
    }
  }

int main()
{
    uint32_t const key[4]={0x01234567,0x89ABCDEF,0xFEDCBA98,0x76543210};
    uint32_t data[2]={0x12345678,0x87654321};
    uint32_t *sent=data;
    btea(sent,2,key);
    printf("coded:%x  %x\n",sent[0],sent[1]);
    btea(sent,-2,key);
    printf("decoded:%x  %x\n",sent[0],sent[1]);
    return 0;
}

BTEA算法C语言实现

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原文地址：http://blog.csdn.net/libinjlu/article/details/43030369