openssl_encrypt加密数组值无法解密及continue语句执行异常咨询

问题根因与修复方案 #

1. 相同明文加密结果不一致、无法解密的问题 #

根因为变量名冲突：代码顶部定义的加密密钥变量名为$key，但内层遍历二维数组列的foreach语句将列名赋值给了$key变量，导致加密时实际传入的密钥并非预定义的有效密钥，而是当前列的键名字符串，因此加密结果错误无法解密。
修复方案：将遍历列使用的变量重命名，避免和密钥变量重名，这里统一将密钥变量重命名为$encryption_key规避冲突。

2. 不加密[0]、[1]列的逻辑不生效的问题 #

根因为判断条件错误：现有判断条件if ($items < 2)中的$items是当前行的完整数组，并非当前列的序号，且数组的列键是带方括号的字符串格式（如"[0]"），无法直接和数字比较。
修复方案：先提取列键中的数字再做判断，修改判断逻辑即可实现跳过前两列加密。

修正后的完整代码 #

<?php
header( 'Content-Type: text/html; charset=utf-8' );

echo "Below is a 3-row, 2-dimensional array displaying sections, fields and values";
$bgyaa = array (
'[0]' => array ( 
    '[0]' => '2',
    '[1]' => 'bgyaa.ZBRDE5aTZsUGZmWQ',
    '[2]' => '12346',
    '[3]' => 'John Citizen',
    '[4]' => 'noy-pic-1.jpg',
    '[5]' => 'noy-pic-2.jpg',
    '[6]' => 'RESIDENT',
    '[7]' => '777 Sarangani Street',
    '[8]' => '03/27/84',
    '[9]' => 'B',
    '[10]' => '287-865-194',
    '[11]' =>' '),
'[1]' => array ( 
    '[0]' => '3',
    '[1]' => 'bgyaa.ZMTEtpTC5qVGNTUQ',
    '[2]' => '12347',
    '[3]' => 'Dominador Pridas',
    '[4]' => 'domeng-pic-1.jpg',
    '[5]' => 'domeng-pic-2.jpg',
    '[6]' => 'TENANT',
    '[7]' => '321 Mango Drive',
    '[8]' => '03/27/84',
    '[9]' => 'B',
    '[10]' => '287-865-194',
    '[11]' =>' ' ),
'[2]' => array ( 
    '[0]' => '4',
    '[1]' => 'bgyaa.ZpcEpteDJOZlBVQQ',
    '[2]' => '12348',
    '[3]' => 'Taylor Swift',
    '[4]' => 'taylorswift-pic-1.jpg',
    '[5]' => 'taylorswift-pic-2.jpg',
    '[6]' => 'TENANT',
    '[7]' => '826 Anonas Street',
    '[8]' => '03/27/84',
    '[9]' => 'B',
    '[10]' => '287-865-194',
    '[11]' =>' ' ), 
);


echo "<pre>";
foreach ($bgyaa as $section => $items)
{
    foreach ($items as $col_key => $value)
    {
        echo "$section:\t$col_key:\t$value<br/>";
    }
}                       

$encryption_key="c871754451c2b89d4cdb1b14705be457b7fabe967af6a559f3d20c79ded5b5ff18675e56fa77d75fdcd47c34271bb74e372d6d04652f7aa6f529a838ca4aa6bd";
$iv= "f1e64276d153ad8a"; // this iv value is 16 bytes of hex characters
$cipher = "aes-256-cbc-hmac-sha256";

if (in_array($cipher, openssl_get_cipher_methods()))
{
    $ivlen = openssl_cipher_iv_length($cipher);
    $plain_text = 'John Citizen';
    $encrypted = openssl_encrypt($plain_text, $cipher, $encryption_key, $options=0, $iv);
    echo "<br/><br/><br/>Bellw are from direct encrytion of the plain text name<br/>";
    echo "plain text is John Citizen " . "<br/>";
    echo "encrypted text is " . $encrypted . "<br/><br/><br/>";
}

echo "And then below are openssl_encrypt (cipher aes-256-cbc) encrypted array codes beside their plain text original values<br/>";
foreach ($bgyaa as $section => $items)     // section is the sub array (starts from 0)
// items are rows
{
    foreach ($items as $col_key => $value) 
    //key represents field or column
    //value represents the values of row
    {
        $col_index = trim($col_key, '[]');
        if ($col_index < 2) 
        {
            continue; //跳过前两列不加密
        }
        $encrypted = '';
        if (in_array($cipher, openssl_get_cipher_methods()))
        {
            $ivlen = openssl_cipher_iv_length($cipher);             
            $encrypted = openssl_encrypt($value, $cipher, $encryption_key, $options=0, $iv);
        }                   
        echo $col_key . " : " . $encrypted . "  :  " . $value . "<br/>";                            
    }
}

echo "</pre>";   

?>

生产环境使用注意：加密IV不要固定写死，需要为每条加密数据生成独立随机IV，和密文一起存储，降低安全风险。

内容的提问来源于stack exchange，提问作者osarte2021