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ACME Client

A comprehensive PHP ACME v2 client library for automating SSL/TLS certificate management with Let's Encrypt, ZeroSSL, and other ACME-compatible Certificate Authorities.

Language / 语言: English | 中文

Features

ACME v2 Protocol Support: Full compatibility with ACME v2 specification
Multiple CA Support: Works with Let's Encrypt, ZeroSSL, and other ACME providers
Account Management: Create, store, and manage ACME accounts
Certificate Operations: Request, renew, and revoke SSL certificates
Domain Validation: Support for HTTP-01 and DNS-01 challenges
ARI Support: Automatic Renewal Information for optimal renewal timing
Flexible Key Types: Support for RSA and ECC keys
Comprehensive Logging: Built-in PSR-3 compatible logging
Easy Integration: Simple and intuitive API design

Requirements

PHP 8.2 or higher
OpenSSL extension
cURL extension
JSON extension
mbstring extension

Installation

Install via Composer:

composer require alapi/acme-client

Quick Start

1. Create Local Account Keys

You have two ways to create and manage ACME account keys:

Option A: Using existing keys with Account class

<?php
require_once 'vendor/autoload.php';

use ALAPI\Acme\Accounts\Account;

// Create account from existing private key string
$privateKeyPem = '-----BEGIN PRIVATE KEY-----...-----END PRIVATE KEY-----';
$account = new Account($privateKeyPem);

// Or create account with both private and public keys
$publicKeyPem = '-----BEGIN PUBLIC KEY-----...-----END PUBLIC KEY-----';
$account = new Account($privateKeyPem, $publicKeyPem);

// Or create account from private key only (public key will be extracted)
$account = Account::fromPrivateKey($privateKeyPem);

Option B: Using AccountStorage for file-based key management

<?php
require_once 'vendor/autoload.php';

use ALAPI\Acme\Utils\AccountStorage;

// Create new ECC account and save to files (recommended)
$account = AccountStorage::createAndSave(
    directory: 'storage',
    name: 'my-account',
    keyType: 'ECC',
    keySize: 'P-384'
);

// Or create RSA account and save to files
$rsaAccount = AccountStorage::createAndSave(
    directory: 'storage', 
    name: 'my-rsa-account',
    keyType: 'RSA',
    keySize: 4096
);

echo "Account keys created and saved successfully!\n";

2. Initialize ACME Client

<?php
require_once 'vendor/autoload.php';

use ALAPI\Acme\AcmeClient;
use ALAPI\Acme\Accounts\Account;
use ALAPI\Acme\Utils\AccountStorage;
use ALAPI\Acme\Http\Clients\ClientFactory;

// Option A: Load account from files
$account = AccountStorage::loadFromFiles('storage', 'my-account');

// Option B: Create account from existing keys
$privateKey = '-----BEGIN PRIVATE KEY-----...-----END PRIVATE KEY-----';
$account = new Account($privateKey);

// Create HTTP client with optional proxy
$httpClient = ClientFactory::create(timeout: 30, options: [
    // 'proxy' => 'http://proxy.example.com:8080'
]);

// Initialize client for Let's Encrypt production
$acmeClient = new AcmeClient(
    staging: false, // Set to true for testing
    localAccount: $account,
    httpClient: $httpClient
);

// Or use ZeroSSL
$zeroSslClient = new AcmeClient(
    localAccount: $account,
    httpClient: $httpClient,
    baseUrl: 'https://acme.zerossl.com/v2/DV90/directory'
);

3. Register ACME Account

For Let's Encrypt (no EAB required):

try {
    // Register account with Let's Encrypt
    $accountData = $acmeClient->account()->create(
        contacts: ['mailto:admin@example.com']
    );
    
    echo "Account registered successfully!\n";
    echo "Account URL: " . $accountData->url . "\n";
} catch (Exception $e) {
    echo "Registration failed: " . $e->getMessage() . "\n";
}

For ZeroSSL (EAB required):

try {
    // Get EAB credentials from ZeroSSL dashboard
    $eabKid = 'your-eab-kid';
    $eabHmacKey = 'your-eab-hmac-key';
    
    $accountData = $zeroSslClient->account()->create(
        eabKid: $eabKid,
        eabHmacKey: $eabHmacKey,
        contacts: ['mailto:admin@example.com']
    );
    
    echo "ZeroSSL account registered successfully!\n";
} catch (Exception $e) {
    echo "Registration failed: " . $e->getMessage() . "\n";
}

4. Request Certificate

<?php
use ALAPI\Acme\Enums\AuthorizationChallengeEnum;

try {
    // Get account data
    $accountData = $acmeClient->account()->get();
    
    // Create new order for domains
    $domains = ['example.com', 'www.example.com'];
    $order = $acmeClient->order()->new($accountData, $domains);
    
    echo "Order created: " . $order->url . "\n";
    echo "Status: " . $order->status . "\n";
    
    // Check domain validations
    $validations = $acmeClient->domainValidation()->status($order);
    
    foreach ($validations as $validation) {
        $domain = $validation->identifier['value'];
        echo "Domain: $domain - Status: " . $validation->status . "\n";
        
        if ($validation->isPending()) {
            // Get validation data for HTTP-01 challenge
            $challenges = $acmeClient->domainValidation()->getValidationData(
                [$validation], 
                AuthorizationChallengeEnum::HTTP
            );
            
            foreach ($challenges as $challenge) {
                echo "HTTP Challenge for $domain:\n";
                echo "  File: " . $challenge['filename'] . "\n";
                echo "  Content: " . $challenge['content'] . "\n";
                echo "  Place it at: http://$domain/.well-known/acme-challenge/" . $challenge['filename'] . "\n\n";
            }
        }
    }
} catch (Exception $e) {
    echo "Error: " . $e->getMessage() . "\n";
}

5. Complete Domain Validation

After placing the challenge files on your web server:

try {
    // Trigger validation for each domain
    foreach ($validations as $validation) {
        if ($validation->isPending()) {
            $response = $acmeClient->domainValidation()->validate(
                $accountData,
                $validation,
                AuthorizationChallengeEnum::HTTP,
                localTest: true // Performs local validation first
            );
            
            echo "Validation triggered for: " . $validation->identifier['value'] . "\n";
        }
    }
    
    // Wait for validation to complete
    $maxAttempts = 10;
    $attempt = 0;
    
    do {
        sleep(5);
        $attempt++;
        
        // Check order status
        $currentOrder = $acmeClient->order()->get($accountData, $order->url);
        echo "Order status: " . $currentOrder->status . "\n";
        
        if ($currentOrder->status === 'ready') {
            echo "All validations completed successfully!\n";
            break;
        }
        
        if ($currentOrder->status === 'invalid') {
            echo "Order validation failed!\n";
            break;
        }
        
    } while ($attempt < $maxAttempts);
    
} catch (Exception $e) {
    echo "Validation error: " . $e->getMessage() . "\n";
}

6. Generate and Submit CSR

use ALAPI\Acme\Security\Cryptography\OpenSsl;

try {
    if ($currentOrder->status === 'ready') {
        // Generate Certificate private key
        $certificatePrivateKey = OpenSsl::generatePrivateKey('RSA', 2048);
        
        // Generate Certificate Signing Request (CSR) using OpenSsl helper
        $csrString = OpenSsl::generateCsr($domains, $certificatePrivateKey);
        
        // Export private key for saving
        $privateKeyString = OpenSsl::openSslKeyToString($certificatePrivateKey);
        
        // Submit CSR to finalize order
        $finalizedOrder = $acmeClient->order()->finalize(
            $accountData,
            $currentOrder,
            $csrString
        );
        
        echo "Order finalized successfully!\n";
        echo "Certificate URL: " . $finalizedOrder->certificateUrl . "\n";
        
        // Download certificate bundle
        $certificateBundle = $acmeClient->certificate()->get(
            $accountData,
            $finalizedOrder->certificateUrl
        );
        
        // Save certificate and private key
        file_put_contents('certificate.pem', $certificateBundle->certificate);
        file_put_contents('fullchain.pem', $certificateBundle->fullchain);
        file_put_contents('private-key.pem', $privateKeyString);
        
        echo "Certificate saved to certificate.pem\n";
        echo "Fullchain certificate saved to fullchain.pem\n";
        echo "Private key saved to private-key.pem\n";
    }
    
} catch (Exception $e) {
    echo "Certificate generation error: " . $e->getMessage() . "\n";
}

Advanced Usage

DNS-01 Challenge

For wildcard certificates or when HTTP validation isn't possible:

// Get DNS challenge data
$dnsChallenge = $acmeClient->domainValidation()->getValidationData(
    [$validation],
    AuthorizationChallengeEnum::DNS
);

foreach ($dnsChallenge as $challenge) {
    echo "DNS Challenge for " . $challenge['domain'] . ":\n";
    echo "  Record Name: " . $challenge['domain'] . "\n";
    echo "  Record Type: TXT\n";
    echo "  Record Value: " . $challenge['digest'] . "\n\n";
}

// After adding DNS records, trigger validation
$response = $acmeClient->domainValidation()->validate(
    $accountData,
    $validation,
    AuthorizationChallengeEnum::DNS,
    localTest: true
);

Certificate Renewal with ARI

use ALAPI\Acme\Management\RenewalManager;

// Load existing certificate
$certificatePem = file_get_contents('certificate.pem');

// Create renewal manager
$renewalManager = $acmeClient->renewalManager(defaultRenewalDays: 30);

// Check if renewal is needed
if ($renewalManager->shouldRenew($certificatePem)) {
    echo "Certificate needs renewal\n";
    
    // Get ARI information if supported
    if ($acmeClient->directory()->supportsARI()) {
        $renewalInfo = $acmeClient->renewalInfo()->getFromCertificate($certificatePem);
        
        echo "Suggested renewal window:\n";
        echo "  Start: " . $renewalInfo->suggestedWindow['start'] . "\n";
        echo "  End: " . $renewalInfo->suggestedWindow['end'] . "\n";
        
        if ($renewalInfo->shouldRenewNow()) {
            echo "ARI recommends renewing now\n";
            // Proceed with renewal...
        }
    }
} else {
    echo "Certificate renewal not needed yet\n";
}

Certificate Revocation

try {
    // Load certificate to revoke
    $certificatePem = file_get_contents('certificate.pem');
    
    // Revoke certificate
    $success = $acmeClient->certificate()->revoke(
        $certificatePem,
        reason: 1 // 0=unspecified, 1=keyCompromise, 2=cACompromise, 3=affiliationChanged, 4=superseded, 5=cessationOfOperation
    );
    
    if ($success) {
        echo "Certificate revoked successfully\n";
    } else {
        echo "Certificate revocation failed\n";
    }
    
} catch (Exception $e) {
    echo "Revocation error: " . $e->getMessage() . "\n";
}

Multiple Certificate Authorities

// Let's Encrypt
$letsEncrypt = new AcmeClient(
    staging: false,
    localAccount: $account,
    httpClient: $httpClient
);

// ZeroSSL
$zeroSSL = new AcmeClient(
    localAccount: $account,
    httpClient: $httpClient,
    baseUrl: 'https://acme.zerossl.com/v2/DV90/directory'
);

// Google Trust Services
$googleCA = new AcmeClient(
    localAccount: $account,
    httpClient: $httpClient,
    baseUrl: 'https://dv.acme-v02.api.pki.goog/directory'
);

Custom HTTP Client Configuration

use ALAPI\Acme\Http\Clients\ClientFactory;

$httpClient = ClientFactory::create(30, [
    'proxy' => 'http://proxy.example.com:8080',
    'verify' => true, // SSL verification
    'timeout' => 30,
    'connect_timeout' => 10,
    'headers' => [
        'User-Agent' => 'MyApp ACME Client 1.0'
    ]
]);

Logging

use Monolog\Logger;
use Monolog\Handler\StreamHandler;

// Create logger
$logger = new Logger('acme');
$logger->pushHandler(new StreamHandler('acme.log', Logger::INFO));

// Set logger on client
$acmeClient->setLogger($logger);

Configuration

Account Management Options

Using AccountStorage for file-based management:

use ALAPI\Acme\Utils\AccountStorage;

// Check if account files exist
if (AccountStorage::exists('storage', 'my-account')) {
    $account = AccountStorage::loadFromFiles('storage', 'my-account');
} else {
    $account = AccountStorage::createAndSave('storage', 'my-account');
}

// Load or create account automatically
$account = AccountStorage::loadOrCreate(
    directory: 'storage',
    name: 'my-account',
    keyType: 'ECC',
    keySize: 'P-384'
);

Using Account class for existing keys:

use ALAPI\Acme\Accounts\Account;

// From existing private key
$privateKey = file_get_contents('/path/to/private.key');
$account = new Account($privateKey);

// With both private and public keys
$privateKey = file_get_contents('/path/to/private.key');
$publicKey = file_get_contents('/path/to/public.key');
$account = new Account($privateKey, $publicKey);

// Create new account with specific key type
$account = Account::createECC('P-384');  // or 'P-256', 'P-384'
$account = Account::createRSA(4096);     // or 2048, 3072

// Get account information
echo "Key Type: " . $account->getKeyType() . "\n";
echo "Key Size: " . $account->getKeySize() . "\n";

Error Handling

use ALAPI\Acme\Exceptions\AcmeException;
use ALAPI\Acme\Exceptions\AcmeAccountException;
use ALAPI\Acme\Exceptions\DomainValidationException;
use ALAPI\Acme\Exceptions\AcmeCertificateException;

try {
    // ACME operations here
} catch (AcmeAccountException $e) {
    echo "Account error: " . $e->getMessage() . "\n";
    echo "Detail: " . $e->getDetail() . "\n";
    echo "Type: " . $e->getAcmeType() . "\n";
} catch (DomainValidationException $e) {
    echo "Validation error: " . $e->getMessage() . "\n";
} catch (AcmeCertificateException $e) {
    echo "Certificate error: " . $e->getMessage() . "\n";
} catch (AcmeException $e) {
    echo "ACME error: " . $e->getMessage() . "\n";
} catch (Exception $e) {
    echo "General error: " . $e->getMessage() . "\n";
}

Testing

Run the test suite:

composer test

Run static analysis:

composer analyse

Fix code style:

composer cs-fix

Security Considerations

Private Keys: Store private keys securely with appropriate file permissions (600)
Account Keys: Keep account keys separate from certificate keys
Staging Environment: Use staging environment for testing
Rate Limits: Be aware of CA rate limits
Validation: Always validate challenges locally before triggering ACME validation

Contributing

Fork the repository
Create a feature branch
Make your changes
Add tests for new functionality
Run the test suite
Submit a pull request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

If you encounter any issues or have questions:

Check the documentation
Search existing issues
Create a new issue if needed

alapi / acme-client

Maintainers

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