当前位置: 首页 > 图文教程 > 网络编程 > PHP > PHP教程:TEA算法实现

PHP
利用discuz实现PHP大文件上传应用实例代码
php 遍历显示文件夹下所有目录、所有文件的函数,没有分页的代码
php在字符串中查找另一个字符串
php下HTTP Response中的Chunked编码实现方法
PHP实现定时生成HTML网站首页实例代码
PHP下一个非常全面获取图象信息的函数
PHP strtr() 函数使用说明
php 删除无限级目录与文件代码共享
php AJAX实例根据邮编自动完成地址信息
php miniBB中文乱码问题解决方法
cmd下运行php脚本
PHP 遍历XP文件夹下所有文件
php 移除数组重复元素的一点说明
discuz论坛 用户登录 后台程序代码
Optimizer与Debugger兼容性问题的解决方法
Zend Studio 无法启动的问题解决方法
php 页面执行时间计算代码
php smarty的预保留变量总结
php获取网页内容方法总结
php读取msn上的用户信息类

PHP教程:TEA算法实现


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-09-28   浏览: 236 ::
收藏到网摘: n/a

算法简单,而且效率高,每次可以操作8个字节的数据,加密解密的KEY为16字节,即包含4个int数据的int型数组,加密轮数应为8的倍数,一般比较常用的轮数为64,32,16,QQ原来就是用TEA16来还原密码的.

TEA算法
核心为:


#include <stdint.h>

void encrypt (uint32_t* v, uint32_t* k) {
    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 */
    for (i=0; i < 32; 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 */
    v[0]=v0; v[1]=v1;
}

void decrypt (uint32_t* v, uint32_t* k) {
    uint32_t v0=v[0], v1=v[1], sum=0xC6EF3720, 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 */
    for (i=0; i<32; i++) {                         /* basic cycle start */
        v1 -= ((v0<<4) + k2) ^ (v0 + sum) ^ ((v0>>5) + k3);
        v0 -= ((v1<<4) + k0) ^ (v1 + sum) ^ ((v1>>5) + k1);
        sum -= delta;                                  
    }                                              /* end cycle */
    v[0]=v0; v[1]=v1;
}

PHP部分代码非我原创,大家可以了解一下这方面的知识

<?php
$date = '8345354023476-3434';
$key = '12345';
$t = new tea ( );
$tea = $t->encrypt ( $date, $key );
$eetea = $t->decrypt ( $tea, $key );
var_dump ( $tea );
var_dump ( $eetea );
class tea {
    private $a, $b, $c, $d;
    private $n_iter;
    public function __construct() {
        $this->setIter ( 32 );
    }
    private function setIter($n_iter) {
        $this->n_iter = $n_iter;
    }
    private function getIter() {
        return $this->n_iter;
    }
    public function encrypt($data, $key) {
        // resize data to 32 bits (4 bytes)
        $n = $this->_resize ( $data, 4 );
       
        // convert data to long
        $data_long [0] = $n;
        $n_data_long = $this->_str2long ( 1, $data, $data_long );
       
        // resize data_long to 64 bits (2 longs of 32 bits)
        $n = count ( $data_long );
        if (($n & 1) == 1) {
            $data_long [$n] = chr ( 0 );
            $n_data_long ++;
        }
       
        // resize key to a multiple of 128 bits (16 bytes)
        $this->_resize ( $key, 16, true );
        if ('' == $key)
            $key = '0000000000000000';
           
        // convert key to long
        $n_key_long = $this->_str2long ( 0, $key, $key_long );
       
        // encrypt the long data with the key
        $enc_data = '';
        $w = array (0, 0 );
        $j = 0;
        $k = array (0, 0, 0, 0 );
        for($i = 0; $i < $n_data_long; ++ $i) {
            // get next key part of 128 bits
            if ($j + 4 <= $n_key_long) {
                $k [0] = $key_long [$j];
                $k [1] = $key_long [$j + 1];
                $k [2] = $key_long [$j + 2];
                $k [3] = $key_long [$j + 3];
            } else {
                $k [0] = $key_long [$j % $n_key_long];
                $k [1] = $key_long [($j + 1) % $n_key_long];
                $k [2] = $key_long [($j + 2) % $n_key_long];
                $k [3] = $key_long [($j + 3) % $n_key_long];
            }
            $j = ($j + 4) % $n_key_long;
           
            $this->_encipherLong ( $data_long [$i], $data_long [++ $i], $w, $k );
           
            // append the enciphered longs to the result
            $enc_data .= $this->_long2str ( $w [0] );
            $enc_data .= $this->_long2str ( $w [1] );
        }
       
        return $enc_data;
    }
    public function decrypt($enc_data, $key) {
        // convert data to long
        $n_enc_data_long = $this->_str2long ( 0, $enc_data, $enc_data_long );
       
        // resize key to a multiple of 128 bits (16 bytes)
        $this->_resize ( $key, 16, true );
        if ('' == $key)
            $key = '0000000000000000';
           
        // convert key to long
        $n_key_long = $this->_str2long ( 0, $key, $key_long );
       
        // decrypt the long data with the key
        $data = '';
        $w = array (0, 0 );
        $j = 0;
        $len = 0;
        $k = array (0, 0, 0, 0 );
        $pos = 0;
       
        for($i = 0; $i < $n_enc_data_long; $i += 2) {
            // get next key part of 128 bits
            if ($j + 4 <= $n_key_long) {
                $k [0] = $key_long [$j];
                $k [1] = $key_long [$j + 1];
                $k [2] = $key_long [$j + 2];
                $k [3] = $key_long [$j + 3];
            } else {
                $k [0] = $key_long [$j % $n_key_long];
                $k [1] = $key_long [($j + 1) % $n_key_long];
                $k [2] = $key_long [($j + 2) % $n_key_long];
                $k [3] = $key_long [($j + 3) % $n_key_long];
            }
            $j = ($j + 4) % $n_key_long;
           
            $this->_decipherLong ( $enc_data_long [$i], $enc_data_long [$i + 1], $w, $k );
           
            // append the deciphered longs to the result data (remove padding)
            if (0 == $i) {
                $len = $w [0];
                if (4 <= $len) {
                    $data .= $this->_long2str ( $w [1] );
                } else {
                    $data .= substr ( $this->_long2str ( $w [1] ), 0, $len % 4 );
                }
            } else {
                $pos = ($i - 1) * 4;
                if ($pos + 4 <= $len) {
                    $data .= $this->_long2str ( $w [0] );
                   
                    if ($pos + 8 <= $len) {
                        $data .= $this->_long2str ( $w [1] );
                    } elseif ($pos + 4 < $len) {
                        $data .= substr ( $this->_long2str ( $w [1] ), 0, $len % 4 );
                    }
                } else {
                    $data .= substr ( $this->_long2str ( $w [0] ), 0, $len % 4 );
                }
            }
        }
        return $data;
    }
    private function _encipherLong($y, $z, &$w, &$k) {
        $sum = ( integer ) 0;
        $delta = 0x9E3779B9;
        $n = ( integer ) $this->n_iter;
       
        while ( $n -- > 0 ) {
                       //C v0 += ((v1<<4) + k0) ^ (v1 + sum) ^ ((v1>>5) + k1);
                       //C v1 += ((v0<<4) + k2) ^ (v0 + sum) ^ ((v0>>5) + k3); 
            $sum = $this->_add ( $sum, $delta );
            $y = $this->_add ( $y, $this->_add ( ($z << 4),$this->a) ^ $this->_add($z , $sum) ^ $this->_add($this->_rshift ( $z, 5 ), $this->b )  );
            $z = $this->_add ( $z, $this->_add ( ($y << 4),$this->a) ^ $this->_add($y , $sum) ^ $this->_add($this->_rshift ( $y, 5 ), $this->b )  );
        }
       
        $w [0] = $y;
        $w [1] = $z;
    }
    private function _decipherLong($y, $z, &$w, &$k) {
        // sum = delta<<5, in general sum = delta * n
        $sum = 0xC6EF3720;
        $delta = 0x9E3779B9;
        $n = ( integer ) $this->n_iter;
       
        while ( $n -- > 0 ) {
                    //C v1 -= ((v0<<4) + k2) ^ (v0 + sum) ^ ((v0>>5) + k3);
                    //C v0 -= ((v1<<4) + k0) ^ (v1 + sum) ^ ((v1>>5) + k1);
            $z = $this->_add ( $z, -($this->_add ( ($y << 4),$this->a) ^ $this->_add($y , $sum) ^ $this->_add($this->_rshift ( $y, 5 ), $this->b ) ) );
            $y = $this->_add ( $y, - ($this->_add ( ($z << 4),$this->a) ^ $this->_add($z , $sum) ^ $this->_add($this->_rshift ( $z, 5 ), $this->b ) ) );
            $sum = $this->_add ( $sum, - $delta );
            }
       
        $w [0] = $y;
        $w [1] = $z;
    }
    private function _resize(&$data, $size, $nonull = false) {
        $n = strlen ( $data );
        $nmod = $n % $size;
        if (0 == $nmod)
            $nmod = $size;
       
        if ($nmod > 0) {
            if ($nonull) {
                for($i = $n; $i < $n - $nmod + $size; ++ $i) {
                    $data [$i] = $data [$i % $n];
                }
            } else {
                for($i = $n; $i < $n - $nmod + $size; ++ $i) {
                    $data [$i] = chr ( 0 );
                }
            }
        }
        return $n;
    }
    private function _hex2bin($str) {
        $len = strlen ( $str );
        return pack ( 'H' . $len, $str );
    }
    private function _str2long($start, &$data, &$data_long) {
        $n = strlen ( $data );
       
        $tmp = unpack ( 'N*', $data );
        $j = $start;
       
        foreach ( $tmp as $value )
            $data_long [$j ++] = $value;
       
        return $j;
    }
    private function _long2str($l) {
        return pack ( 'N', $l );
    }
   
   
    private function _rshift($integer, $n) {
        // convert to 32 bits
        if (0xffffffff < $integer || - 0xffffffff > $integer) {
            $integer = fmod ( $integer, 0xffffffff + 1 );
        }
       
        // convert to unsigned integer
        if (0x7fffffff < $integer) {
            $integer -= 0xffffffff + 1.0;
        } elseif (- 0x80000000 > $integer) {
            $integer += 0xffffffff + 1.0;
        }
       
        // do right shift
        if (0 > $integer) {
            $integer &= 0x7fffffff; // remove sign bit before shift
            $integer >>= $n; // right shift
            $integer |= 1 << (31 - $n); // set shifted sign bit
        } else {
            $integer >>= $n; // use normal right shift
        }
       
        return $integer;
    }
    private function _add($i1, $i2) {
        $result = 0.0;
       
        foreach ( func_get_args () as $value ) {
            // remove sign if necessary
            if (0.0 > $value) {
                $value -= 1.0 + 0xffffffff;
            }
           
            $result += $value;
        }
       
        // convert to 32 bits
        if (0xffffffff < $result || - 0xffffffff > $result) {
            $result = fmod ( $result, 0xffffffff + 1 );
        }
       
        // convert to signed integer
        if (0x7fffffff < $result) {
            $result -= 0xffffffff + 1.0;
        } elseif (- 0x80000000 > $result) {
            $result += 0xffffffff + 1.0;
        }
       
        return $result;
    }
   
// }}}
}
?>

上面的是TEA的算法,XTEA的算法为:

 


#include <stdint.h>

void encipher(unsigned int num_rounds, uint32_t v[2], uint32_t const k[4]) {
    unsigned int i;
    uint32_t v0=v[0], v1=v[1], sum=0, delta=0x9E3779B9;
    for (i=0; i < num_rounds; i++) {
        v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
        sum += delta;
        v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]);
    }
    v[0]=v0; v[1]=v1;
}

void decipher(unsigned int num_rounds, uint32_t v[2], uint32_t const k[4]) {
    unsigned int i;
    uint32_t v0=v[0], v1=v[1], delta=0x9E3779B9, sum=delta*num_rounds;
    for (i=0; i < num_rounds; i++) {
        v1 &#8722;= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]);
        sum &#8722;= delta;
        v0 &#8722;= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
    }
    v[0]=v0; v[1]=v1;
}

那PHP中只需要把运算的位置改下就OK

 

    private function _teaencipherLong($y, $z, &$w, &$k) {
        $sum = ( integer ) 0;
        $delta = 0x9E3779B9;
        $n = ( integer ) $this->n_iter;
       
        while ( $n -- > 0 ) {
            $y = $this->_add ( $y, $this->_add ( $z << 4 ^ $this->_rshift ( $z, 5 ), $z ) ^ $this->_add ( $sum, $k [$sum & 3] ) );
            $sum = $this->_add ( $sum, $delta );
            $z = $this->_add ( $z, $this->_add ( $y << 4 ^ $this->_rshift ( $y, 5 ), $y ) ^ $this->_add ( $sum, $k [$this->_rshift ( $sum, 11 ) & 3] ) );
        }
       
        $w [0] = $y;
        $w [1] = $z;
    }   
    private function _decipherLong($y, $z, &$w, &$k) {
        // sum = delta<<5, in general sum = delta * n
        $sum = 0xC6EF3720;
        $delta = 0x9E3779B9;
        $n = ( integer ) $this->n_iter;
       
        while ( $n -- > 0 ) {
            $z = $this->_add ( $z, - ($this->_add ( $y << 4 ^ $this->_rshift ( $y, 5 ), $y ) ^ $this->_add ( $sum, $k [$this->_rshift ( $sum, 11 ) & 3] )) );
            $sum = $this->_add ( $sum, - $delta );
            $y = $this->_add ( $y, - ($this->_add ( $z << 4 ^ $this->_rshift ( $z, 5 ), $z ) ^ $this->_add ( $sum, $k [$sum & 3] )) );
        }
       
        $w [0] = $y;
        $w [1] = $z;
    }

XXTEA的算法
核心为

 


#define MX (z>>5^y<<2) + (y>>3^z<<4)^(sum^y) + (k[p&3^e]^z);

  long btea(long* v, long n, long* k) {
    unsigned long z=v[n-1], y=v[0], sum=0, e, DELTA=0x9e3779b9;
    long p, q ;
    if (n > 1) {          /* Coding Part */
      q = 6 + 52/n;
      while (q-- > 0) {
        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;
      }
      return 0 ;
    } else if (n < -1) {  /* Decoding Part */
      n = -n;
      q = 6 + 52/n;
      sum = q*DELTA ;
      while (sum != 0) {
        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;
        sum -= DELTA;
      }
      return 0;
    }
    return 1;
  }

也是运算不一样,这个就不写了,有人已经写过这方面的代码了