概要：

今天在使用微信開放平臺對接一個內容管理系統的時候，在繫結公眾號的時候一直失敗

原因：

除錯的時候發現，直接原因是因為開放平臺裡面填寫的授權事件（該授權事件每十分鐘會通送一次事件來更新ticket），即：

這個地方填寫的url，除錯發現，這個URL沒錯，微信也有每10分鐘推送過來，但是到最後一直接收不到ticket，看程式碼發現是因為解密微信過來的資料的時候報錯了：

<?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;
	}
 

解決：

查詢資料發現，可以通過OpenSSL來代替Mcrypt（前提是已經安裝了OpenSSL擴充套件，不過一般都是預設安裝的），所以上面的程式碼可以改為：

<?php

function aes_decode($message, $encodingaeskey = '', $appid = '') {
	$key = base64_decode($encodingaeskey . '=');

	$ciphertext_dec = base64_decode($message);
	$iv = substr($key, 0, 16);

	/* mcrypt對稱解密程式碼在PHP7.1已經被拋棄了，所以使用下面的openssl來代替
	$module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');
	mcrypt_generic_init($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;
	}
 

上面的解密已經修改了，那麼對應的Mcrypt加密也需要修改，如果不改的話會導致不能全網釋出以及不能推送訊息等事件

加密的原始碼如下：

<?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對稱加密程式碼在PHP7.1已經被拋棄了，所以使用下面的openssl來代替
    $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;
}