php-simple symmetric encryption algorithm and conversion function between string and hexadecimal, php-hexadecimal_PHP tutorial

php-simple symmetric encryption algorithm and conversion function between string and hexadecimal, php-hex

/**
* Encryption of simple symmetric encryption algorithm
* @param String $string The string to be encrypted
* @param String $skey Encryption EKY
* @return String
*/
function encode($string = '', $skey = 'textphp') {
$skey = str_split(base64_encode($skey));
$strArr = str_split(base64_encode($string));
$strCount = count($strArr);
foreach ($skey as $key => $value) {
$key < $strCount && $strArr[$key].=$value;
　}
　return str_replace('=', 'O0O0O', join('', $strArr));
}

/**
* Decryption of simple symmetric encryption algorithm
* @param String $string The string to be decrypted
* @param String $skey Decryption KEY
* @return String
*/
function decode($string = '', $skey = 'textphp') {
　$skey = str_split(base64_encode($skey));
　$ strArr = str_split(str_replace('O0O0O', '=', $string), 2);
$strCount = count($strArr);
foreach ($skey as $key => $value) {
　　$key < $strCount && $strArr[$key][1] === $value && $strArr[$key] = $strArr[$key][0];
　　}
　　 return base64_decode(join('', $strArr));
}

//Convert the string to hexadecimal
function str2hex($str, $encoded = 'GBK') {
$hex = '';
if ($encoded == 'GBK' ) {
　　$str = mb_convert_encoding($str, 'GBK', 'UTF-8');
　　}
　for ($i = 0, $length = mb_strlen($str); $i < ; $length; $i ) {
  $hex .= dechex(ord($str{$i}));
 }
 return $hex;
}

//Convert hexadecimal to string
function hex2str($hex, $encoded = 'GBK') {
　$str = '';
　$arr = str_split($hex, 2 );
foreach ($arr as $bit) {
$str .= chr(hexdec($bit));
}
if ($encoded == 'GBK') {
　　$str = mb_convert_encoding($str, 'UTF-8', 'GBK');
　　}
　　return $str;
}