javascript - Some issues related to aes128 encryption

class aes {

<code>const KEY = "625202f9149e061d";
const IV = "5efd3f6060e20330";

/**</code>

• pkcs7 complement code

• @param string $string plain text

• @param int $blocksize Blocksize , in byte

• @return String
  */

1. function addPkcs7Padding($string, $blocksize = 32) {

   <code>   $len = strlen($string); //取得字符串长度
      $pad = $blocksize - ($len % $blocksize); //取得补码的长度
      $string .= str_repeat(chr($pad), $pad); //用ASCII码为补码长度的字符， 补足最后一段
      return $string;</code>

   }

2. aes128cbcEncrypt($str, $iv = self::IV, $key = self::KEY) { // $this->addPkcs7Padding($str,16)

   <code>   $base = (mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $this->addPkcs7Padding($str, 16), MCRYPT_MODE_CBC, $iv));
      return $this->strToHex($base);</code>

   }

3. strToHex($string) {//Convert string to hexadecimal

   <code>   $hex = "";
      $tmp = "";
      for ($i = 0; $i < strlen($string); $i++) {
          $tmp = dechex(ord($string[$i]));
          $hex.= strlen($tmp) == 1 ? "0" . $tmp : $tmp;
      }
      $hex = strtoupper($hex);
      return $hex;</code>

   }
   Aes encryption codes found online include PHP and android. Can a kind person tell me about each step of this encryption process? $aes = new aes(); $aes->aes128cbcEncrypt('token'); or help. Write a corresponding js version = =

Reply content:

class aes {

<code>const KEY = "625202f9149e061d";
const IV = "5efd3f6060e20330";

/**</code>

• pkcs7 complement code

• @param string $string plain text

• @param int $blocksize Blocksize , in byte

• @return String
  */

1. function addPkcs7Padding($string, $blocksize = 32) {

   <code>   $len = strlen($string); //取得字符串长度
      $pad = $blocksize - ($len % $blocksize); //取得补码的长度
      $string .= str_repeat(chr($pad), $pad); //用ASCII码为补码长度的字符， 补足最后一段
      return $string;</code>

   }

2. aes128cbcEncrypt($str, $iv = self::IV, $key = self::KEY) { // $this->addPkcs7Padding($str,16)

   <code>   $base = (mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $this->addPkcs7Padding($str, 16), MCRYPT_MODE_CBC, $iv));
      return $this->strToHex($base);</code>

   }

3. strToHex($string) {//Convert string to hexadecimal

   <code>   $hex = "";
      $tmp = "";
      for ($i = 0; $i < strlen($string); $i++) {
          $tmp = dechex(ord($string[$i]));
          $hex.= strlen($tmp) == 1 ? "0" . $tmp : $tmp;
      }
      $hex = strtoupper($hex);
      return $hex;</code>

   }
   Aes encryption codes found online include PHP and android. Can a kind person tell me about each step of this encryption process? $aes = new aes(); $aes->aes128cbcEncrypt('token'); or help. Write a corresponding js version = =

It sounds quite complicated, just take a look at this link.
http://yinghuayuan8866.blog.163.com/blog/static/2245702720121225658625/