php中加密解密DES类的简单使用方法示例

class DES
{
  var $key; // 密钥
  var $iv; // 偏移量

  function __construct( $key, $iv=0 ) {
    $this->key = $key;
    if( $iv == 0 ) {

      $this->iv = $key;

    } else {

      $this->iv = $iv; 
      // 创建初始向量, 并且检测密钥长度, Windows 平台请使用 MCRYPT_RAND
      // mcrypt_create_iv ( mcrypt_get_block_size (MCRYPT_DES, MCRYPT_MODE_CBC), MCRYPT_DEV_RANDOM );

    }

  }

  function encrypt($str) {
    //加密，返回大写十六进制字符串
    $size = mcrypt_get_block_size ( MCRYPT_DES, MCRYPT_MODE_CBC );

    $str = $this->pkcs5Pad ( $str, $size );
 // bin2hex 把 ASCII 字符的字符串转换为十六进制值
    return strtoupper( bin2hex( mcrypt_cbc(MCRYPT_DES, $this->key, $str, MCRYPT_ENCRYPT, $this->iv ) ) );

  }

  function decrypt($str) {
    //解密

    $strBin = $this->hex2bin( strtolower( $str ) );

    $str = mcrypt_cbc( MCRYPT_DES, $this->key, $strBin, MCRYPT_DECRYPT, $this->iv );

    $str = $this->pkcs5Unpad( $str );

    return $str;

  }


  function hex2bin($hexData) {

    $binData = "";

    for($i = 0; $i < strlen ( $hexData ); $i += 2) {

      $binData .= chr ( hexdec ( substr ( $hexData, $i, 2 ) ) );

    }

    return $binData;

  }

  function pkcs5Pad($text, $blocksize) {

    $pad = $blocksize - (strlen ( $text ) % $blocksize);

    return $text . str_repeat ( chr ( $pad ), $pad );

  }

  function pkcs5Unpad($text) {

    $pad = ord ( $text {strlen ( $text ) - 1} );

    if ($pad > strlen ( $text ))

      return false;

    if (strspn ( $text, chr ( $pad ), strlen ( $text ) - $pad ) != $pad)

      return false;

    return substr ( $text, 0, - 1 * $pad );
  }
}

class DES7
{

  //要改的加密, 使用 openssl

  public function desEncrypt($str,$key) {

    $iv = $key;

    $data = openssl_encrypt($str,"DES-CBC",$key,OPENSSL_RAW_DATA,$iv);

    $data = strtolower(bin2hex($data));

    return $data;

  }

  //要改的解密

  public function desDecrypt($str,$key) {

    $iv = $key;

    return openssl_decrypt (hex2bin($str), 'DES-CBC', $key, OPENSSL_RAW_DATA,$iv);

  }

}