php des加密

http://www.jb51.net/article/56410.htm

class DES
{
 var $key;
 var $iv; //偏移量
 
 function DES( $key, $iv=0 ) {
 //key长度8例如:1234abcd
  $this->key = $key;
  if( $iv == 0 ) {
   $this->iv = $key;
  } else {
   $this->iv = $iv; //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 );
  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 );
 }
}