php - 将加密/解密函数从 PHP 转换为 NodeJS

Question

我正在考虑将一个项目从 PHP 移植到 NodeJS，其中包含一个用于加密和解密字符串的加密/解密类，我正在尝试将其转换为 NodeJS。

下面是现有的 PHP 函数

public function encrypt($data): string
{
    return base64_encode(openssl_encrypt($data, 'AES-256-CBC', $this->cipher_key,
        OPENSSL_RAW_DATA, $this->iv));
}

public function decrypt($encryptedString)
{
    try
    {
        return $this->strippadding(openssl_decrypt(base64_decode($encryptedString), 'AES-256-CBC',
        $this->cipher_key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $this->iv));
    }
    catch (\Exception $e)
    {
        Logger::log("Failed to decrypt string. Error: " . $e->getMessage());
        return $encryptedString;
    }
}

private function strippadding($string)
{
    error_reporting(0);
    $slast = ord(substr($string, -1));
    $slastc = chr($slast);
    //$pcheck = substr($string, -$slast);
    if(preg_match('/'.$slastc.'{'.$slast.'}/', $string)){
        return substr($string, 0, strlen($string)-$slast);
    } else {
        return null;
    }
}

下面是我移植到 NodeJS 的代码

const encrypt = (data, key, iv) => {
    const cipher = crypto.createCipheriv('AES-256-CBC', key, iv);
    let encrypted = cipher.update(data, 'utf8', 'base64');
    encrypted += cipher.final('base64');
    return encrypted;
}

const decrypt = (encryptedString, key, iv) => {
    try {
        const decipher = crypto.createDecipheriv('AES-256-CBC', key, iv);
        decipher.setAutoPadding(false);
        let decrypted = decipher.update(encryptedString, 'base64', 'utf-8');
        decrypted += decipher.final('utf-8');
        return strippadding(decrypted);
        return decrypted
    } catch (e) {
        console.log(`Failed to decrypt string. Error: ${e.message}`);
        return encryptedString;
    }
}

const strippadding = (string) => {
    const slast = string.charCodeAt(string.length - 1);
    const slastc = String.fromCharCode(slast);
    const regex = new RegExp(`${slastc}{${slast}}`);
    if (regex.test(string)) {
        return string.substring(0, string.length - slast);
    } else {
        return null;
    }
}

当我尝试获取现有的加密字符串并使用相同的 key 和 iv 对其进行解密时，我得到一个 NULL 返回，因为 strippadding 函数中的正则表达式似乎不起作用，但我不明白为什么。如果我不使用 strippadding 而只是打印解密的变量，我只会得到随机符号。

如果我尝试加密一个字符串，我会得到与我期望的完全不同的字符串，所以我有一些不太正确的东西，但不确定是什么。

Answer 1

因为根据您的评论，实现应该只解密使用 encrypt() 方法生成的密文，并且 encrypt() 方法应用默认的 PKCS# 7 填充，默认的 PKCS#7 填充也可以用于解密，即不再需要自定义取消填充 strippadding()。一个可能的 NodeJS 实现是:

var crypto = require('crypto');

const encrypt = (data, key, iv) => {
    const cipher = crypto.createCipheriv('AES-256-CBC', key, iv);
    let encrypted = cipher.update(data, 'utf8', 'base64');
    encrypted += cipher.final('base64');
    return encrypted;
}

const decrypt = (encryptedString, key, iv) => {
    try {
        const decipher = crypto.createDecipheriv('AES-256-CBC', key, iv);
        let decrypted = decipher.update(encryptedString, 'base64', 'utf-8');
        decrypted += decipher.final('utf-8');
        return decrypted
    } catch (e) {
        console.log(`Failed to decrypt string. Error: ${e.message}`);
        return encryptedString;
    }
}

iv = '0123456789012345';
key = '01234567890123456789012345678901';
plaintext = 'The quick brown fox jumps over the lazy dog';
ciphertext = encrypt(plaintext, key, iv);
console.log(ciphertext); // 4G9jpxHot6qflEAQfUaAoReZQ4DqMdKimblTAtQ5uXAsjmWpkjbskgcEkVzxqYpE
decrypted = decrypt(ciphertext, key, iv);
console.log(decrypted); // The quick brown fox jumps over the lazy dog

---

测试:以下 PHP 代码使用发布的方法 enrypt() 和定制的 decrypt():

class Test {
    private $iv = '0123456789012345';
    private $cipher_key = '01234567890123456789012345678901';
    public function encrypt($data)
    {
        return base64_encode(openssl_encrypt($data, 'AES-256-CBC', $this->cipher_key, OPENSSL_RAW_DATA, $this->iv));
    }
    public function decrypt($data)
    {
        try
        {
            return openssl_decrypt(base64_decode($data), 'AES-256-CBC', $this->cipher_key, OPENSSL_RAW_DATA, $this->iv);
        }
        catch (\Exception $e)
        {
            Logger::log("Failed to decrypt string. Error: " . $e->getMessage());
            return $encryptedString;
        }
    }
}

$test = new Test();
$plaintext = 'The quick brown fox jumps over the lazy dog';
$ciphertext = $test->encrypt($plaintext);
print($ciphertext . PHP_EOL); // 4G9jpxHot6qflEAQfUaAoReZQ4DqMdKimblTAtQ5uXAsjmWpkjbskgcEkVzxqYpE
$decrypted = $test->decrypt($ciphertext);
print($decrypted . PHP_EOL); // The quick brown fox jumps over the lazy dog

对于相同的 key 和明文，密文与 NodeJS 代码相同，解密后的文本类似。