使用ThinkPHP6中集成Acmephp实现SSL证书在线生成，并自动续签。
直接上代码
1，安装Acmephp
用Composer来安装Acmephp。在项目根目录下执行以下命令：

SSL在线生成网址：https://ssl.goolibao.com/ssl

composer require acmephp/acmephp

2，创建证书目录
在config目录下创建一个acmephp.php配置文件，用于配置Acmephp。

return [
    'storage' => [
        'class' => AcmePhpSslStoreFilesystemStore::class,
        'directory' => __DIR__.'/../public/certs',
    ],
    'acme' => [
        'directory' => 'https://acme-v02.api.letsencrypt.org/directory',
        'contact' => ['mailto:admin@example.com'],
    ],
];

在上面的配置中，我们指定了证书存储的目录为public/certs，以及ACME服务器的地址和联系方式。
4，创建SSL证书
用Acmephp的API来创建SSL证书。控制器：

<?php

namespace appcontroller;

use AcmePhpSslPrivateKey;
use AcmePhpSslCertificate;
use AcmePhpCoreAcmeClient;
use AcmePhpBundleAcmeDomainAuthorizationChallengeSolver;
use AcmePhpBundleAcmeDomainAuthorizationChallenge;
use AcmePhpBundleAcmeDomainDomainValidator;
use SymfonyComponentHttpFoundationRequest;

class CertController
{
    public function create(Request $request)
    {
        $domain = $request->get('domain');
        $email = $request->get('email');

        $client = new AcmeClient($domain, $email);

        $solver = new AuthorizationChallengeSolver();

        $challenge = $client->requestAuthorization($domain);

        $solver->solve($challenge, $domain);

        $validator = new DomainValidator();

        $validator->validate($domain);

        $privateKey = new PrivateKey();

        $certificate = new Certificate($client->getCertificateData());

        $privateKey->saveToFile(__DIR__.'/../public/certs/'.$domain.'.key');
        $certificate->saveToFile(__DIR__.'/../public/certs/'.$domain.'.crt');

        return 'OK';
    }
}

我们首先从请求参数中获取域名和电子邮件地址，然后创建一个AcmeClient对象来请求证书。接着，我们通过AuthorizationChallengeSolver来解决验证挑战，然后使用DomainValidator来验证域名。最后，我们将私钥和证书保存到public/certs目录下。
5，自动续签SSL证书
用Acmephp的API来自动续签SSL证书。

<?php

namespace appcontroller;

use AcmePhpSslPrivateKey;
use AcmePhpSslCertificate;
use AcmePhpCoreAcmeClient;
use AcmePhpBundleAcmeDomainAuthorizationChallengeSolver;
use AcmePhpBundleAcmeDomainAuthorizationChallenge;
use AcmePhpBundleAcmeDomainDomainValidator;
use SymfonyComponentHttpFoundationRequest;

class CertController
{
    public function renew(Request $request)
    {
        $domain = $request->get('domain');
        $email = $request->get('email');

        $client = new AcmeClient($domain, $email);

        $certificate = new Certificate(file_get_contents(__DIR__.'/../public/certs/'.$domain.'.crt'));
        $privateKey = new PrivateKey(file_get_contents(__DIR__.'/../public/certs/'.$domain.'.key'));

        $client->renewCertificate($certificate, $privateKey);

        $certificate->saveToFile(__DIR__.'/../public/certs/'.$domain.'.crt');
        $privateKey->saveToFile(__DIR__.'/../public/certs/'.$domain.'.key');

        return 'OK';
    }
}

思路:我们首先从请求参数中获取域名和电子邮件地址，然后创建一个AcmeClient对象来请求证书。接着，我们加载之前生成的证书和私钥文件，然后调用renewCertificate方法来自动续签证书。最后，我们将新的证书和私钥保存到public/certs目录下。