Detailed explanation of how to use OpenSSL instead of Mcrypt encryption and decryption in PHP 7.1_php tips

<?php

function aes_decode($message, $encodingaeskey = '', $appid = '') {

 $key = base64_decode($encodingaeskey . '=');

 $ciphertext_dec = base64_decode($message);

 $iv = substr($key, 0, 16);

 $module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');

 mcrypt_generic_init($module, $key, $iv);

 $decrypted = mdecrypt_generic($module, $ciphertext_dec);

 mcrypt_generic_deinit($module);

 mcrypt_module_close($module);

 $pad = ord(substr($decrypted, -1));

 if ($pad < 1 || $pad > 32) {

 $pad = 0;

 }

<?php

function aes_decode($message, $encodingaeskey = '', $appid = '') {

 $key = base64_decode($encodingaeskey . '=');

 $ciphertext_dec = base64_decode($message);

 $iv = substr($key, 0, 16);

 /* mcrypt对称解密代码在PHP7.1已经被抛弃了，所以使用下面的openssl来代替

 $module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');

 mcrypt_generic_init($module, $key, $iv);

 $decrypted = mdecrypt_generic($module, $ciphertext_dec);

 mcrypt_generic_deinit($module);

 mcrypt_module_close($module);

 */

 $decrypted = openssl_decrypt($ciphertext_dec, 'AES-256-CBC', $key, OPENSSL_RAW_DATA|OPENSSL_ZERO_PADDING, $iv);

 $pad = ord(substr($decrypted, -1));

 if ($pad < 1 || $pad > 32) {

 $pad = 0;

 }

<?php

function aes_encode($message, $encodingaeskey = '', $appid = '') {

 $key = base64_decode($encodingaeskey . '=');

 $text = random(16) . pack("N", strlen($message)) . $message . $appid;

 $iv = substr($key, 0, 16);

 $block_size = 32;

 $text_length = strlen($text);

 $amount_to_pad = $block_size - ($text_length % $block_size);

 if ($amount_to_pad == 0) {

 $amount_to_pad = $block_size;

 }

 $pad_chr = chr($amount_to_pad);

 $tmp = '';

 for ($index = 0; $index < $amount_to_pad; $index++) {

 $tmp .= $pad_chr;

 }

 $text = $text . $tmp;

 $size = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);

 $module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');

 mcrypt_generic_init($module, $key, $iv);

 $encrypted = mcrypt_generic($module, $text);

 mcrypt_generic_deinit($module);

 mcrypt_module_close($module);

 $encrypt_msg = base64_encode($encrypted);

 return $encrypt_msg;

}

<?php

function aes_encode($message, $encodingaeskey = '', $appid = '') {

 $key = base64_decode($encodingaeskey . '=');

 $text = random(16) . pack("N", strlen($message)) . $message . $appid;

 $iv = substr($key, 0, 16);

 $block_size = 32;

 $text_length = strlen($text);

 $amount_to_pad = $block_size - ($text_length % $block_size);

 if ($amount_to_pad == 0) {

 $amount_to_pad = $block_size;

 }

 $pad_chr = chr($amount_to_pad);

 $tmp = '';

 for ($index = 0; $index < $amount_to_pad; $index++) {

 $tmp .= $pad_chr;

 }

 $text = $text . $tmp;

 /* mcrypt对称加密代码在PHP7.1已经被抛弃了，所以使用下面的openssl来代替

 $size = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);

 $module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');

 mcrypt_generic_init($module, $key, $iv);

 $encrypted = mcrypt_generic($module, $text);

 mcrypt_generic_deinit($module);

 mcrypt_module_close($module);

 */

 $encrypted = openssl_encrypt($text, 'AES-256-CBC', $key, OPENSSL_RAW_DATA|OPENSSL_ZERO_PADDING, $iv);

 $encrypt_msg = base64_encode($encrypted);

 return $encrypt_msg;

}