PHP7.2的AES加密类

      一般来说AES加密需要mcrypt扩展的支持，windows的环境下PHP都自带了这个扩展，而linux则需要自己安装这个扩展，但是在PHP7.2以后mcrypt扩展从PHP核心代码中移除。

       所以如果使用PHP7.2之后的版本是无法通过mcrypt扩展实现Aes加密的，那么如何PHP7.2之后如何进行Aes加密呢？官方手册上说mcrypt被OpenSSL取代，所以我们可以通过OpenSSL代替。如下所示：

mcrypt:

<?php

namespace App\Libs\AES;
/**
 * aes 加密 解密类库
 *
 */
class Aes {

    private $key = null;

    /**
     *
     * @param $key 		**
     * @return String
     */
    public function __construct() {
        $this->key = '123';
    }

    /**
     * 加密
     * @param String input 加密的字符串
     * @param String key   解密的key
     * @return HexString
     */
    public function encrypt($input = '') {
        $size = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_ECB);
        $input = $this->pkcs5_pad($input, $size);
        $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_ECB, '');
        $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        mcrypt_generic_init($td, $this->key, $iv);

        $data = mcrypt_generic($td, $input);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);
        $data = base64_encode($data);

        return $data;

    }
    /**
     * 填充方式 pkcs5
     * @param String text 		 原始字符串
     * @param String blocksize   加密长度
     * @return String
     */
    private function pkcs5_pad($text, $blocksize) {
        $pad = $blocksize - (strlen($text) % $blocksize);
        return $text . str_repeat(chr($pad), $pad);
    }

    /**
     * 解密
     * @param String input 解密的字符串
     * @param String key   解密的key
     * @return String
     */
    public function decrypt($sStr) {
        $decrypted= mcrypt_decrypt(MCRYPT_RIJNDAEL_128,$this->key,base64_decode($sStr), MCRYPT_MODE_ECB);
        $dec_s = strlen($decrypted);
        $padding = ord($decrypted[$dec_s-1]);
        $decrypted = substr($decrypted, 0, -$padding);

        return $decrypted;
    }

}

OpenSSL:

<?php

namespace App\Libs\AES;
/**
 * aes 加密 解密类库
 *
 */
class Aes {

    private $hex_iv = 'jagdjagfjkgjkaskkak';

    private $key = 'yrzs';

    function __construct($key) {
        $this->key = $key;
        $this->key = hash('sha256', $this->key, true);
    }
    public function encrypt($input)
    {
        $data = openssl_encrypt($input, 'AES-256-CBC', $this->key, OPENSSL_RAW_DATA, $this->hexToStr($this->hex_iv));
        $data = base64_encode($data);
        return $data;
    }

    public function decrypt($input)
    {
        $decrypted = openssl_decrypt(base64_decode($input), 'AES-256-CBC', $this->key, OPENSSL_RAW_DATA, $this->hexToStr($this->hex_iv));
        return $decrypted;
    }
    private function addpadding($string, $blocksize = 16) {

        $len = strlen($string);

        $pad = $blocksize - ($len % $blocksize);

        $string .= str_repeat(chr($pad), $pad);

        return $string;

    }

    private function strippadding($string) {

        $slast = ord(substr($string, -1));

        $slastc = chr($slast);

        $pcheck = substr($string, -$slast);

        if (preg_match("/$slastc{" . $slast . "}/", $string)) {

            $string = substr($string, 0, strlen($string) - $slast);

            return $string;

        } else {

            return false;

        }

    }

    function hexToStr($hex)
    {

        $string='';

        for ($i=0; $i < strlen($hex)-1; $i+=2)

        {

            $string .= chr(hexdec($hex[$i].$hex[$i+1]));

        }

        return $string;
    }
}